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| author | Adam Harrison <adamdharrison@gmail.com> | 2023-07-06 06:37:41 -0400 |
|---|---|---|
| committer | Adam Harrison <adamdharrison@gmail.com> | 2023-07-06 06:37:41 -0400 |
| commit | 9db10386430479067795bec66bb26343ff176ded (patch) | |
| tree | 5ad0cf95abde7cf03afaf8f70af8549d46b09a46 /lib/mbedtls-2.27.0/library/ssl_msg.c | |
| parent | 57092d80cb07fa1a84873769fa92165426196054 (diff) | |
| download | lite-xl-plugin-manager-9db10386430479067795bec66bb26343ff176ded.tar.gz lite-xl-plugin-manager-9db10386430479067795bec66bb26343ff176ded.zip | |
Removed old mbedtls, replacing with submodule.
Diffstat (limited to 'lib/mbedtls-2.27.0/library/ssl_msg.c')
| -rw-r--r-- | lib/mbedtls-2.27.0/library/ssl_msg.c | 6071 |
1 files changed, 0 insertions, 6071 deletions
diff --git a/lib/mbedtls-2.27.0/library/ssl_msg.c b/lib/mbedtls-2.27.0/library/ssl_msg.c deleted file mode 100644 index 1352b49..0000000 --- a/lib/mbedtls-2.27.0/library/ssl_msg.c +++ /dev/null @@ -1,6071 +0,0 @@ -/* - * Generic SSL/TLS messaging layer functions - * (record layer + retransmission state machine) - * - * Copyright The Mbed TLS Contributors - * SPDX-License-Identifier: Apache-2.0 - * - * Licensed under the Apache License, Version 2.0 (the "License"); you may - * not use this file except in compliance with the License. - * You may obtain a copy of the License at - * - * http://www.apache.org/licenses/LICENSE-2.0 - * - * Unless required by applicable law or agreed to in writing, software - * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT - * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - * See the License for the specific language governing permissions and - * limitations under the License. - */ -/* - * The SSL 3.0 specification was drafted by Netscape in 1996, - * and became an IETF standard in 1999. - * - * http://wp.netscape.com/eng/ssl3/ - * http://www.ietf.org/rfc/rfc2246.txt - * http://www.ietf.org/rfc/rfc4346.txt - */ - -#include "common.h" - -#if defined(MBEDTLS_SSL_TLS_C) - -#if defined(MBEDTLS_PLATFORM_C) -#include "mbedtls/platform.h" -#else -#include <stdlib.h> -#define mbedtls_calloc calloc -#define mbedtls_free free -#endif - -#include "mbedtls/ssl.h" -#include "mbedtls/ssl_internal.h" -#include "mbedtls/debug.h" -#include "mbedtls/error.h" -#include "mbedtls/platform_util.h" -#include "mbedtls/version.h" - -#include "ssl_invasive.h" - -#include <string.h> - -#if defined(MBEDTLS_USE_PSA_CRYPTO) -#include "mbedtls/psa_util.h" -#include "psa/crypto.h" -#endif - -#if defined(MBEDTLS_X509_CRT_PARSE_C) -#include "mbedtls/oid.h" -#endif - -static uint32_t ssl_get_hs_total_len( mbedtls_ssl_context const *ssl ); - -/* - * Start a timer. - * Passing millisecs = 0 cancels a running timer. - */ -void mbedtls_ssl_set_timer( mbedtls_ssl_context *ssl, uint32_t millisecs ) -{ - if( ssl->f_set_timer == NULL ) - return; - - MBEDTLS_SSL_DEBUG_MSG( 3, ( "set_timer to %d ms", (int) millisecs ) ); - ssl->f_set_timer( ssl->p_timer, millisecs / 4, millisecs ); -} - -/* - * Return -1 is timer is expired, 0 if it isn't. - */ -int mbedtls_ssl_check_timer( mbedtls_ssl_context *ssl ) -{ - if( ssl->f_get_timer == NULL ) - return( 0 ); - - if( ssl->f_get_timer( ssl->p_timer ) == 2 ) - { - MBEDTLS_SSL_DEBUG_MSG( 3, ( "timer expired" ) ); - return( -1 ); - } - - return( 0 ); -} - -#if defined(MBEDTLS_SSL_RECORD_CHECKING) -static int ssl_parse_record_header( mbedtls_ssl_context const *ssl, - unsigned char *buf, - size_t len, - mbedtls_record *rec ); - -int mbedtls_ssl_check_record( mbedtls_ssl_context const *ssl, - unsigned char *buf, - size_t buflen ) -{ - int ret = 0; - MBEDTLS_SSL_DEBUG_MSG( 1, ( "=> mbedtls_ssl_check_record" ) ); - MBEDTLS_SSL_DEBUG_BUF( 3, "record buffer", buf, buflen ); - - /* We don't support record checking in TLS because - * (a) there doesn't seem to be a usecase for it, and - * (b) In SSLv3 and TLS 1.0, CBC record decryption has state - * and we'd need to backup the transform here. - */ - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_STREAM ) - { - ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE; - goto exit; - } -#if defined(MBEDTLS_SSL_PROTO_DTLS) - else - { - mbedtls_record rec; - - ret = ssl_parse_record_header( ssl, buf, buflen, &rec ); - if( ret != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 3, "ssl_parse_record_header", ret ); - goto exit; - } - - if( ssl->transform_in != NULL ) - { - ret = mbedtls_ssl_decrypt_buf( ssl, ssl->transform_in, &rec ); - if( ret != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 3, "mbedtls_ssl_decrypt_buf", ret ); - goto exit; - } - } - } -#endif /* MBEDTLS_SSL_PROTO_DTLS */ - -exit: - /* On success, we have decrypted the buffer in-place, so make - * sure we don't leak any plaintext data. */ - mbedtls_platform_zeroize( buf, buflen ); - - /* For the purpose of this API, treat messages with unexpected CID - * as well as such from future epochs as unexpected. */ - if( ret == MBEDTLS_ERR_SSL_UNEXPECTED_CID || - ret == MBEDTLS_ERR_SSL_EARLY_MESSAGE ) - { - ret = MBEDTLS_ERR_SSL_UNEXPECTED_RECORD; - } - - MBEDTLS_SSL_DEBUG_MSG( 1, ( "<= mbedtls_ssl_check_record" ) ); - return( ret ); -} -#endif /* MBEDTLS_SSL_RECORD_CHECKING */ - -#define SSL_DONT_FORCE_FLUSH 0 -#define SSL_FORCE_FLUSH 1 - -#if defined(MBEDTLS_SSL_PROTO_DTLS) - -/* Forward declarations for functions related to message buffering. */ -static void ssl_buffering_free_slot( mbedtls_ssl_context *ssl, - uint8_t slot ); -static void ssl_free_buffered_record( mbedtls_ssl_context *ssl ); -static int ssl_load_buffered_message( mbedtls_ssl_context *ssl ); -static int ssl_load_buffered_record( mbedtls_ssl_context *ssl ); -static int ssl_buffer_message( mbedtls_ssl_context *ssl ); -static int ssl_buffer_future_record( mbedtls_ssl_context *ssl, - mbedtls_record const *rec ); -static int ssl_next_record_is_in_datagram( mbedtls_ssl_context *ssl ); - -static size_t ssl_get_maximum_datagram_size( mbedtls_ssl_context const *ssl ) -{ - size_t mtu = mbedtls_ssl_get_current_mtu( ssl ); -#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH) - size_t out_buf_len = ssl->out_buf_len; -#else - size_t out_buf_len = MBEDTLS_SSL_OUT_BUFFER_LEN; -#endif - - if( mtu != 0 && mtu < out_buf_len ) - return( mtu ); - - return( out_buf_len ); -} - -static int ssl_get_remaining_space_in_datagram( mbedtls_ssl_context const *ssl ) -{ - size_t const bytes_written = ssl->out_left; - size_t const mtu = ssl_get_maximum_datagram_size( ssl ); - - /* Double-check that the write-index hasn't gone - * past what we can transmit in a single datagram. */ - if( bytes_written > mtu ) - { - /* Should never happen... */ - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - - return( (int) ( mtu - bytes_written ) ); -} - -static int ssl_get_remaining_payload_in_datagram( mbedtls_ssl_context const *ssl ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - size_t remaining, expansion; - size_t max_len = MBEDTLS_SSL_OUT_CONTENT_LEN; - -#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) - const size_t mfl = mbedtls_ssl_get_output_max_frag_len( ssl ); - - if( max_len > mfl ) - max_len = mfl; - - /* By the standard (RFC 6066 Sect. 4), the MFL extension - * only limits the maximum record payload size, so in theory - * we would be allowed to pack multiple records of payload size - * MFL into a single datagram. However, this would mean that there's - * no way to explicitly communicate MTU restrictions to the peer. - * - * The following reduction of max_len makes sure that we never - * write datagrams larger than MFL + Record Expansion Overhead. - */ - if( max_len <= ssl->out_left ) - return( 0 ); - - max_len -= ssl->out_left; -#endif - - ret = ssl_get_remaining_space_in_datagram( ssl ); - if( ret < 0 ) - return( ret ); - remaining = (size_t) ret; - - ret = mbedtls_ssl_get_record_expansion( ssl ); - if( ret < 0 ) - return( ret ); - expansion = (size_t) ret; - - if( remaining <= expansion ) - return( 0 ); - - remaining -= expansion; - if( remaining >= max_len ) - remaining = max_len; - - return( (int) remaining ); -} - -/* - * Double the retransmit timeout value, within the allowed range, - * returning -1 if the maximum value has already been reached. - */ -static int ssl_double_retransmit_timeout( mbedtls_ssl_context *ssl ) -{ - uint32_t new_timeout; - - if( ssl->handshake->retransmit_timeout >= ssl->conf->hs_timeout_max ) - return( -1 ); - - /* Implement the final paragraph of RFC 6347 section 4.1.1.1 - * in the following way: after the initial transmission and a first - * retransmission, back off to a temporary estimated MTU of 508 bytes. - * This value is guaranteed to be deliverable (if not guaranteed to be - * delivered) of any compliant IPv4 (and IPv6) network, and should work - * on most non-IP stacks too. */ - if( ssl->handshake->retransmit_timeout != ssl->conf->hs_timeout_min ) - { - ssl->handshake->mtu = 508; - MBEDTLS_SSL_DEBUG_MSG( 2, ( "mtu autoreduction to %d bytes", ssl->handshake->mtu ) ); - } - - new_timeout = 2 * ssl->handshake->retransmit_timeout; - - /* Avoid arithmetic overflow and range overflow */ - if( new_timeout < ssl->handshake->retransmit_timeout || - new_timeout > ssl->conf->hs_timeout_max ) - { - new_timeout = ssl->conf->hs_timeout_max; - } - - ssl->handshake->retransmit_timeout = new_timeout; - MBEDTLS_SSL_DEBUG_MSG( 3, ( "update timeout value to %lu millisecs", - (unsigned long) ssl->handshake->retransmit_timeout ) ); - - return( 0 ); -} - -static void ssl_reset_retransmit_timeout( mbedtls_ssl_context *ssl ) -{ - ssl->handshake->retransmit_timeout = ssl->conf->hs_timeout_min; - MBEDTLS_SSL_DEBUG_MSG( 3, ( "update timeout value to %lu millisecs", - (unsigned long) ssl->handshake->retransmit_timeout ) ); -} -#endif /* MBEDTLS_SSL_PROTO_DTLS */ - -#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL) -int (*mbedtls_ssl_hw_record_init)( mbedtls_ssl_context *ssl, - const unsigned char *key_enc, const unsigned char *key_dec, - size_t keylen, - const unsigned char *iv_enc, const unsigned char *iv_dec, - size_t ivlen, - const unsigned char *mac_enc, const unsigned char *mac_dec, - size_t maclen ) = NULL; -int (*mbedtls_ssl_hw_record_activate)( mbedtls_ssl_context *ssl, int direction) = NULL; -int (*mbedtls_ssl_hw_record_reset)( mbedtls_ssl_context *ssl ) = NULL; -int (*mbedtls_ssl_hw_record_write)( mbedtls_ssl_context *ssl ) = NULL; -int (*mbedtls_ssl_hw_record_read)( mbedtls_ssl_context *ssl ) = NULL; -int (*mbedtls_ssl_hw_record_finish)( mbedtls_ssl_context *ssl ) = NULL; -#endif /* MBEDTLS_SSL_HW_RECORD_ACCEL */ - -/* - * Encryption/decryption functions - */ - -#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) || \ - defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL) - -static size_t ssl_compute_padding_length( size_t len, - size_t granularity ) -{ - return( ( granularity - ( len + 1 ) % granularity ) % granularity ); -} - -/* This functions transforms a (D)TLS plaintext fragment and a record content - * type into an instance of the (D)TLSInnerPlaintext structure. This is used - * in DTLS 1.2 + CID and within TLS 1.3 to allow flexible padding and to protect - * a record's content type. - * - * struct { - * opaque content[DTLSPlaintext.length]; - * ContentType real_type; - * uint8 zeros[length_of_padding]; - * } (D)TLSInnerPlaintext; - * - * Input: - * - `content`: The beginning of the buffer holding the - * plaintext to be wrapped. - * - `*content_size`: The length of the plaintext in Bytes. - * - `max_len`: The number of Bytes available starting from - * `content`. This must be `>= *content_size`. - * - `rec_type`: The desired record content type. - * - * Output: - * - `content`: The beginning of the resulting (D)TLSInnerPlaintext structure. - * - `*content_size`: The length of the resulting (D)TLSInnerPlaintext structure. - * - * Returns: - * - `0` on success. - * - A negative error code if `max_len` didn't offer enough space - * for the expansion. - */ -static int ssl_build_inner_plaintext( unsigned char *content, - size_t *content_size, - size_t remaining, - uint8_t rec_type, - size_t pad ) -{ - size_t len = *content_size; - - /* Write real content type */ - if( remaining == 0 ) - return( -1 ); - content[ len ] = rec_type; - len++; - remaining--; - - if( remaining < pad ) - return( -1 ); - memset( content + len, 0, pad ); - len += pad; - remaining -= pad; - - *content_size = len; - return( 0 ); -} - -/* This function parses a (D)TLSInnerPlaintext structure. - * See ssl_build_inner_plaintext() for details. */ -static int ssl_parse_inner_plaintext( unsigned char const *content, - size_t *content_size, - uint8_t *rec_type ) -{ - size_t remaining = *content_size; - - /* Determine length of padding by skipping zeroes from the back. */ - do - { - if( remaining == 0 ) - return( -1 ); - remaining--; - } while( content[ remaining ] == 0 ); - - *content_size = remaining; - *rec_type = content[ remaining ]; - - return( 0 ); -} -#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID || - MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */ - -/* `add_data` must have size 13 Bytes if the CID extension is disabled, - * and 13 + 1 + CID-length Bytes if the CID extension is enabled. */ -static void ssl_extract_add_data_from_record( unsigned char* add_data, - size_t *add_data_len, - mbedtls_record *rec, - unsigned minor_ver ) -{ - /* Quoting RFC 5246 (TLS 1.2): - * - * additional_data = seq_num + TLSCompressed.type + - * TLSCompressed.version + TLSCompressed.length; - * - * For the CID extension, this is extended as follows - * (quoting draft-ietf-tls-dtls-connection-id-05, - * https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-05): - * - * additional_data = seq_num + DTLSPlaintext.type + - * DTLSPlaintext.version + - * cid + - * cid_length + - * length_of_DTLSInnerPlaintext; - * - * For TLS 1.3, the record sequence number is dropped from the AAD - * and encoded within the nonce of the AEAD operation instead. - */ - - unsigned char *cur = add_data; - -#if defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL) - if( minor_ver != MBEDTLS_SSL_MINOR_VERSION_4 ) -#endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */ - { - ((void) minor_ver); - memcpy( cur, rec->ctr, sizeof( rec->ctr ) ); - cur += sizeof( rec->ctr ); - } - - *cur = rec->type; - cur++; - - memcpy( cur, rec->ver, sizeof( rec->ver ) ); - cur += sizeof( rec->ver ); - -#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) - if( rec->cid_len != 0 ) - { - memcpy( cur, rec->cid, rec->cid_len ); - cur += rec->cid_len; - - *cur = rec->cid_len; - cur++; - - cur[0] = ( rec->data_len >> 8 ) & 0xFF; - cur[1] = ( rec->data_len >> 0 ) & 0xFF; - cur += 2; - } - else -#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ - { - cur[0] = ( rec->data_len >> 8 ) & 0xFF; - cur[1] = ( rec->data_len >> 0 ) & 0xFF; - cur += 2; - } - - *add_data_len = cur - add_data; -} - -#if defined(MBEDTLS_SSL_PROTO_SSL3) - -#define SSL3_MAC_MAX_BYTES 20 /* MD-5 or SHA-1 */ - -/* - * SSLv3.0 MAC functions - */ -static void ssl_mac( mbedtls_md_context_t *md_ctx, - const unsigned char *secret, - const unsigned char *buf, size_t len, - const unsigned char *ctr, int type, - unsigned char out[SSL3_MAC_MAX_BYTES] ) -{ - unsigned char header[11]; - unsigned char padding[48]; - int padlen; - int md_size = mbedtls_md_get_size( md_ctx->md_info ); - int md_type = mbedtls_md_get_type( md_ctx->md_info ); - - /* Only MD5 and SHA-1 supported */ - if( md_type == MBEDTLS_MD_MD5 ) - padlen = 48; - else - padlen = 40; - - memcpy( header, ctr, 8 ); - header[ 8] = (unsigned char) type; - header[ 9] = (unsigned char)( len >> 8 ); - header[10] = (unsigned char)( len ); - - memset( padding, 0x36, padlen ); - mbedtls_md_starts( md_ctx ); - mbedtls_md_update( md_ctx, secret, md_size ); - mbedtls_md_update( md_ctx, padding, padlen ); - mbedtls_md_update( md_ctx, header, 11 ); - mbedtls_md_update( md_ctx, buf, len ); - mbedtls_md_finish( md_ctx, out ); - - memset( padding, 0x5C, padlen ); - mbedtls_md_starts( md_ctx ); - mbedtls_md_update( md_ctx, secret, md_size ); - mbedtls_md_update( md_ctx, padding, padlen ); - mbedtls_md_update( md_ctx, out, md_size ); - mbedtls_md_finish( md_ctx, out ); -} -#endif /* MBEDTLS_SSL_PROTO_SSL3 */ - -#if defined(MBEDTLS_GCM_C) || \ - defined(MBEDTLS_CCM_C) || \ - defined(MBEDTLS_CHACHAPOLY_C) -static int ssl_transform_aead_dynamic_iv_is_explicit( - mbedtls_ssl_transform const *transform ) -{ - return( transform->ivlen != transform->fixed_ivlen ); -} - -/* Compute IV := ( fixed_iv || 0 ) XOR ( 0 || dynamic_IV ) - * - * Concretely, this occurs in two variants: - * - * a) Fixed and dynamic IV lengths add up to total IV length, giving - * IV = fixed_iv || dynamic_iv - * - * This variant is used in TLS 1.2 when used with GCM or CCM. - * - * b) Fixed IV lengths matches total IV length, giving - * IV = fixed_iv XOR ( 0 || dynamic_iv ) - * - * This variant occurs in TLS 1.3 and for TLS 1.2 when using ChaChaPoly. - * - * See also the documentation of mbedtls_ssl_transform. - * - * This function has the precondition that - * - * dst_iv_len >= max( fixed_iv_len, dynamic_iv_len ) - * - * which has to be ensured by the caller. If this precondition - * violated, the behavior of this function is undefined. - */ -static void ssl_build_record_nonce( unsigned char *dst_iv, - size_t dst_iv_len, - unsigned char const *fixed_iv, - size_t fixed_iv_len, - unsigned char const *dynamic_iv, - size_t dynamic_iv_len ) -{ - size_t i; - - /* Start with Fixed IV || 0 */ - memset( dst_iv, 0, dst_iv_len ); - memcpy( dst_iv, fixed_iv, fixed_iv_len ); - - dst_iv += dst_iv_len - dynamic_iv_len; - for( i = 0; i < dynamic_iv_len; i++ ) - dst_iv[i] ^= dynamic_iv[i]; -} -#endif /* MBEDTLS_GCM_C || MBEDTLS_CCM_C || MBEDTLS_CHACHAPOLY_C */ - -int mbedtls_ssl_encrypt_buf( mbedtls_ssl_context *ssl, - mbedtls_ssl_transform *transform, - mbedtls_record *rec, - int (*f_rng)(void *, unsigned char *, size_t), - void *p_rng ) -{ - mbedtls_cipher_mode_t mode; - int auth_done = 0; - unsigned char * data; - unsigned char add_data[13 + 1 + MBEDTLS_SSL_CID_OUT_LEN_MAX ]; - size_t add_data_len; - size_t post_avail; - - /* The SSL context is only used for debugging purposes! */ -#if !defined(MBEDTLS_DEBUG_C) - ssl = NULL; /* make sure we don't use it except for debug */ - ((void) ssl); -#endif - - /* The PRNG is used for dynamic IV generation that's used - * for CBC transformations in TLS 1.1 and TLS 1.2. */ -#if !( defined(MBEDTLS_SSL_SOME_SUITES_USE_CBC) && \ - ( defined(MBEDTLS_SSL_PROTO_TLS1_1) || defined(MBEDTLS_SSL_PROTO_TLS1_2) ) ) - ((void) f_rng); - ((void) p_rng); -#endif - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> encrypt buf" ) ); - - if( transform == NULL ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "no transform provided to encrypt_buf" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - if( rec == NULL - || rec->buf == NULL - || rec->buf_len < rec->data_offset - || rec->buf_len - rec->data_offset < rec->data_len -#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) - || rec->cid_len != 0 -#endif - ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad record structure provided to encrypt_buf" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - - data = rec->buf + rec->data_offset; - post_avail = rec->buf_len - ( rec->data_len + rec->data_offset ); - MBEDTLS_SSL_DEBUG_BUF( 4, "before encrypt: output payload", - data, rec->data_len ); - - mode = mbedtls_cipher_get_cipher_mode( &transform->cipher_ctx_enc ); - - if( rec->data_len > MBEDTLS_SSL_OUT_CONTENT_LEN ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "Record content %" MBEDTLS_PRINTF_SIZET - " too large, maximum %" MBEDTLS_PRINTF_SIZET, - rec->data_len, - (size_t) MBEDTLS_SSL_OUT_CONTENT_LEN ) ); - return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); - } - - /* The following two code paths implement the (D)TLSInnerPlaintext - * structure present in TLS 1.3 and DTLS 1.2 + CID. - * - * See ssl_build_inner_plaintext() for more information. - * - * Note that this changes `rec->data_len`, and hence - * `post_avail` needs to be recalculated afterwards. - * - * Note also that the two code paths cannot occur simultaneously - * since they apply to different versions of the protocol. There - * is hence no risk of double-addition of the inner plaintext. - */ -#if defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL) - if( transform->minor_ver == MBEDTLS_SSL_MINOR_VERSION_4 ) - { - size_t padding = - ssl_compute_padding_length( rec->data_len, - MBEDTLS_SSL_TLS1_3_PADDING_GRANULARITY ); - if( ssl_build_inner_plaintext( data, - &rec->data_len, - post_avail, - rec->type, - padding ) != 0 ) - { - return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL ); - } - - rec->type = MBEDTLS_SSL_MSG_APPLICATION_DATA; - } -#endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */ - -#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) - /* - * Add CID information - */ - rec->cid_len = transform->out_cid_len; - memcpy( rec->cid, transform->out_cid, transform->out_cid_len ); - MBEDTLS_SSL_DEBUG_BUF( 3, "CID", rec->cid, rec->cid_len ); - - if( rec->cid_len != 0 ) - { - size_t padding = - ssl_compute_padding_length( rec->data_len, - MBEDTLS_SSL_CID_PADDING_GRANULARITY ); - /* - * Wrap plaintext into DTLSInnerPlaintext structure. - * See ssl_build_inner_plaintext() for more information. - * - * Note that this changes `rec->data_len`, and hence - * `post_avail` needs to be recalculated afterwards. - */ - if( ssl_build_inner_plaintext( data, - &rec->data_len, - post_avail, - rec->type, - padding ) != 0 ) - { - return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL ); - } - - rec->type = MBEDTLS_SSL_MSG_CID; - } -#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ - - post_avail = rec->buf_len - ( rec->data_len + rec->data_offset ); - - /* - * Add MAC before if needed - */ -#if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC) - if( mode == MBEDTLS_MODE_STREAM || - ( mode == MBEDTLS_MODE_CBC -#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) - && transform->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED -#endif - ) ) - { - if( post_avail < transform->maclen ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "Buffer provided for encrypted record not large enough" ) ); - return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL ); - } - -#if defined(MBEDTLS_SSL_PROTO_SSL3) - if( transform->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ) - { - unsigned char mac[SSL3_MAC_MAX_BYTES]; - ssl_mac( &transform->md_ctx_enc, transform->mac_enc, - data, rec->data_len, rec->ctr, rec->type, mac ); - memcpy( data + rec->data_len, mac, transform->maclen ); - } - else -#endif -#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \ - defined(MBEDTLS_SSL_PROTO_TLS1_2) - if( transform->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_1 ) - { - unsigned char mac[MBEDTLS_SSL_MAC_ADD]; - - ssl_extract_add_data_from_record( add_data, &add_data_len, rec, - transform->minor_ver ); - - mbedtls_md_hmac_update( &transform->md_ctx_enc, add_data, - add_data_len ); - mbedtls_md_hmac_update( &transform->md_ctx_enc, - data, rec->data_len ); - mbedtls_md_hmac_finish( &transform->md_ctx_enc, mac ); - mbedtls_md_hmac_reset( &transform->md_ctx_enc ); - - memcpy( data + rec->data_len, mac, transform->maclen ); - } - else -#endif - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - - MBEDTLS_SSL_DEBUG_BUF( 4, "computed mac", data + rec->data_len, - transform->maclen ); - - rec->data_len += transform->maclen; - post_avail -= transform->maclen; - auth_done++; - } -#endif /* MBEDTLS_SSL_SOME_MODES_USE_MAC */ - - /* - * Encrypt - */ -#if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER) - if( mode == MBEDTLS_MODE_STREAM ) - { - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - size_t olen; - MBEDTLS_SSL_DEBUG_MSG( 3, ( "before encrypt: msglen = %" MBEDTLS_PRINTF_SIZET ", " - "including %d bytes of padding", - rec->data_len, 0 ) ); - - if( ( ret = mbedtls_cipher_crypt( &transform->cipher_ctx_enc, - transform->iv_enc, transform->ivlen, - data, rec->data_len, - data, &olen ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_crypt", ret ); - return( ret ); - } - - if( rec->data_len != olen ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - } - else -#endif /* MBEDTLS_ARC4_C || MBEDTLS_CIPHER_NULL_CIPHER */ - -#if defined(MBEDTLS_GCM_C) || \ - defined(MBEDTLS_CCM_C) || \ - defined(MBEDTLS_CHACHAPOLY_C) - if( mode == MBEDTLS_MODE_GCM || - mode == MBEDTLS_MODE_CCM || - mode == MBEDTLS_MODE_CHACHAPOLY ) - { - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - unsigned char iv[12]; - unsigned char *dynamic_iv; - size_t dynamic_iv_len; - int dynamic_iv_is_explicit = - ssl_transform_aead_dynamic_iv_is_explicit( transform ); - - /* Check that there's space for the authentication tag. */ - if( post_avail < transform->taglen ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "Buffer provided for encrypted record not large enough" ) ); - return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL ); - } - - /* - * Build nonce for AEAD encryption. - * - * Note: In the case of CCM and GCM in TLS 1.2, the dynamic - * part of the IV is prepended to the ciphertext and - * can be chosen freely - in particular, it need not - * agree with the record sequence number. - * However, since ChaChaPoly as well as all AEAD modes - * in TLS 1.3 use the record sequence number as the - * dynamic part of the nonce, we uniformly use the - * record sequence number here in all cases. - */ - dynamic_iv = rec->ctr; - dynamic_iv_len = sizeof( rec->ctr ); - - ssl_build_record_nonce( iv, sizeof( iv ), - transform->iv_enc, - transform->fixed_ivlen, - dynamic_iv, - dynamic_iv_len ); - - /* - * Build additional data for AEAD encryption. - * This depends on the TLS version. - */ - ssl_extract_add_data_from_record( add_data, &add_data_len, rec, - transform->minor_ver ); - - MBEDTLS_SSL_DEBUG_BUF( 4, "IV used (internal)", - iv, transform->ivlen ); - MBEDTLS_SSL_DEBUG_BUF( 4, "IV used (transmitted)", - dynamic_iv, - dynamic_iv_is_explicit ? dynamic_iv_len : 0 ); - MBEDTLS_SSL_DEBUG_BUF( 4, "additional data used for AEAD", - add_data, add_data_len ); - MBEDTLS_SSL_DEBUG_MSG( 3, ( "before encrypt: msglen = %" MBEDTLS_PRINTF_SIZET ", " - "including 0 bytes of padding", - rec->data_len ) ); - - /* - * Encrypt and authenticate - */ - - if( ( ret = mbedtls_cipher_auth_encrypt_ext( &transform->cipher_ctx_enc, - iv, transform->ivlen, - add_data, add_data_len, - data, rec->data_len, /* src */ - data, rec->buf_len - (data - rec->buf), /* dst */ - &rec->data_len, - transform->taglen ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_auth_encrypt", ret ); - return( ret ); - } - MBEDTLS_SSL_DEBUG_BUF( 4, "after encrypt: tag", - data + rec->data_len - transform->taglen, - transform->taglen ); - /* Account for authentication tag. */ - post_avail -= transform->taglen; - - /* - * Prefix record content with dynamic IV in case it is explicit. - */ - if( dynamic_iv_is_explicit != 0 ) - { - if( rec->data_offset < dynamic_iv_len ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "Buffer provided for encrypted record not large enough" ) ); - return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL ); - } - - memcpy( data - dynamic_iv_len, dynamic_iv, dynamic_iv_len ); - rec->data_offset -= dynamic_iv_len; - rec->data_len += dynamic_iv_len; - } - - auth_done++; - } - else -#endif /* MBEDTLS_GCM_C || MBEDTLS_CCM_C || MBEDTLS_CHACHAPOLY_C */ -#if defined(MBEDTLS_SSL_SOME_SUITES_USE_CBC) - if( mode == MBEDTLS_MODE_CBC ) - { - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - size_t padlen, i; - size_t olen; - - /* Currently we're always using minimal padding - * (up to 255 bytes would be allowed). */ - padlen = transform->ivlen - ( rec->data_len + 1 ) % transform->ivlen; - if( padlen == transform->ivlen ) - padlen = 0; - - /* Check there's enough space in the buffer for the padding. */ - if( post_avail < padlen + 1 ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "Buffer provided for encrypted record not large enough" ) ); - return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL ); - } - - for( i = 0; i <= padlen; i++ ) - data[rec->data_len + i] = (unsigned char) padlen; - - rec->data_len += padlen + 1; - post_avail -= padlen + 1; - -#if defined(MBEDTLS_SSL_PROTO_TLS1_1) || defined(MBEDTLS_SSL_PROTO_TLS1_2) - /* - * Prepend per-record IV for block cipher in TLS v1.1 and up as per - * Method 1 (6.2.3.2. in RFC4346 and RFC5246) - */ - if( transform->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_2 ) - { - if( f_rng == NULL ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "No PRNG provided to encrypt_record routine" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - - if( rec->data_offset < transform->ivlen ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "Buffer provided for encrypted record not large enough" ) ); - return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL ); - } - - /* - * Generate IV - */ - ret = f_rng( p_rng, transform->iv_enc, transform->ivlen ); - if( ret != 0 ) - return( ret ); - - memcpy( data - transform->ivlen, transform->iv_enc, - transform->ivlen ); - - } -#endif /* MBEDTLS_SSL_PROTO_TLS1_1 || MBEDTLS_SSL_PROTO_TLS1_2 */ - - MBEDTLS_SSL_DEBUG_MSG( 3, ( "before encrypt: msglen = %" MBEDTLS_PRINTF_SIZET ", " - "including %" MBEDTLS_PRINTF_SIZET - " bytes of IV and %" MBEDTLS_PRINTF_SIZET " bytes of padding", - rec->data_len, transform->ivlen, - padlen + 1 ) ); - - if( ( ret = mbedtls_cipher_crypt( &transform->cipher_ctx_enc, - transform->iv_enc, - transform->ivlen, - data, rec->data_len, - data, &olen ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_crypt", ret ); - return( ret ); - } - - if( rec->data_len != olen ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - -#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) - if( transform->minor_ver < MBEDTLS_SSL_MINOR_VERSION_2 ) - { - /* - * Save IV in SSL3 and TLS1 - */ - memcpy( transform->iv_enc, transform->cipher_ctx_enc.iv, - transform->ivlen ); - } - else -#endif - { - data -= transform->ivlen; - rec->data_offset -= transform->ivlen; - rec->data_len += transform->ivlen; - } - -#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) - if( auth_done == 0 ) - { - unsigned char mac[MBEDTLS_SSL_MAC_ADD]; - - /* - * MAC(MAC_write_key, seq_num + - * TLSCipherText.type + - * TLSCipherText.version + - * length_of( (IV +) ENC(...) ) + - * IV + // except for TLS 1.0 - * ENC(content + padding + padding_length)); - */ - - if( post_avail < transform->maclen) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "Buffer provided for encrypted record not large enough" ) ); - return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL ); - } - - ssl_extract_add_data_from_record( add_data, &add_data_len, - rec, transform->minor_ver ); - - MBEDTLS_SSL_DEBUG_MSG( 3, ( "using encrypt then mac" ) ); - MBEDTLS_SSL_DEBUG_BUF( 4, "MAC'd meta-data", add_data, - add_data_len ); - - mbedtls_md_hmac_update( &transform->md_ctx_enc, add_data, - add_data_len ); - mbedtls_md_hmac_update( &transform->md_ctx_enc, - data, rec->data_len ); - mbedtls_md_hmac_finish( &transform->md_ctx_enc, mac ); - mbedtls_md_hmac_reset( &transform->md_ctx_enc ); - - memcpy( data + rec->data_len, mac, transform->maclen ); - - rec->data_len += transform->maclen; - post_avail -= transform->maclen; - auth_done++; - } -#endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */ - } - else -#endif /* MBEDTLS_SSL_SOME_SUITES_USE_CBC) */ - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - - /* Make extra sure authentication was performed, exactly once */ - if( auth_done != 1 ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= encrypt buf" ) ); - - return( 0 ); -} - -#if defined(MBEDTLS_SSL_SOME_SUITES_USE_TLS_CBC) -/* - * Turn a bit into a mask: - * - if bit == 1, return the all-bits 1 mask, aka (size_t) -1 - * - if bit == 0, return the all-bits 0 mask, aka 0 - * - * This function can be used to write constant-time code by replacing branches - * with bit operations using masks. - * - * This function is implemented without using comparison operators, as those - * might be translated to branches by some compilers on some platforms. - */ -static size_t mbedtls_ssl_cf_mask_from_bit( size_t bit ) -{ - /* MSVC has a warning about unary minus on unsigned integer types, - * but this is well-defined and precisely what we want to do here. */ -#if defined(_MSC_VER) -#pragma warning( push ) -#pragma warning( disable : 4146 ) -#endif - return -bit; -#if defined(_MSC_VER) -#pragma warning( pop ) -#endif -} - -/* - * Constant-flow mask generation for "less than" comparison: - * - if x < y, return all bits 1, that is (size_t) -1 - * - otherwise, return all bits 0, that is 0 - * - * This function can be used to write constant-time code by replacing branches - * with bit operations using masks. - * - * This function is implemented without using comparison operators, as those - * might be translated to branches by some compilers on some platforms. - */ -static size_t mbedtls_ssl_cf_mask_lt( size_t x, size_t y ) -{ - /* This has the most significant bit set if and only if x < y */ - const size_t sub = x - y; - - /* sub1 = (x < y) ? 1 : 0 */ - const size_t sub1 = sub >> ( sizeof( sub ) * 8 - 1 ); - - /* mask = (x < y) ? 0xff... : 0x00... */ - const size_t mask = mbedtls_ssl_cf_mask_from_bit( sub1 ); - - return( mask ); -} - -/* - * Constant-flow mask generation for "greater or equal" comparison: - * - if x >= y, return all bits 1, that is (size_t) -1 - * - otherwise, return all bits 0, that is 0 - * - * This function can be used to write constant-time code by replacing branches - * with bit operations using masks. - * - * This function is implemented without using comparison operators, as those - * might be translated to branches by some compilers on some platforms. - */ -static size_t mbedtls_ssl_cf_mask_ge( size_t x, size_t y ) -{ - return( ~mbedtls_ssl_cf_mask_lt( x, y ) ); -} - -/* - * Constant-flow boolean "equal" comparison: - * return x == y - * - * This function can be used to write constant-time code by replacing branches - * with bit operations - it can be used in conjunction with - * mbedtls_ssl_cf_mask_from_bit(). - * - * This function is implemented without using comparison operators, as those - * might be translated to branches by some compilers on some platforms. - */ -static size_t mbedtls_ssl_cf_bool_eq( size_t x, size_t y ) -{ - /* diff = 0 if x == y, non-zero otherwise */ - const size_t diff = x ^ y; - - /* MSVC has a warning about unary minus on unsigned integer types, - * but this is well-defined and precisely what we want to do here. */ -#if defined(_MSC_VER) -#pragma warning( push ) -#pragma warning( disable : 4146 ) -#endif - - /* diff_msb's most significant bit is equal to x != y */ - const size_t diff_msb = ( diff | -diff ); - -#if defined(_MSC_VER) -#pragma warning( pop ) -#endif - - /* diff1 = (x != y) ? 1 : 0 */ - const size_t diff1 = diff_msb >> ( sizeof( diff_msb ) * 8 - 1 ); - - return( 1 ^ diff1 ); -} - -/* - * Constant-flow conditional memcpy: - * - if c1 == c2, equivalent to memcpy(dst, src, len), - * - otherwise, a no-op, - * but with execution flow independent of the values of c1 and c2. - * - * This function is implemented without using comparison operators, as those - * might be translated to branches by some compilers on some platforms. - */ -static void mbedtls_ssl_cf_memcpy_if_eq( unsigned char *dst, - const unsigned char *src, - size_t len, - size_t c1, size_t c2 ) -{ - /* mask = c1 == c2 ? 0xff : 0x00 */ - const size_t equal = mbedtls_ssl_cf_bool_eq( c1, c2 ); - const unsigned char mask = (unsigned char) mbedtls_ssl_cf_mask_from_bit( equal ); - - /* dst[i] = c1 == c2 ? src[i] : dst[i] */ - for( size_t i = 0; i < len; i++ ) - dst[i] = ( src[i] & mask ) | ( dst[i] & ~mask ); -} - -/* - * Compute HMAC of variable-length data with constant flow. - * - * Only works with MD-5, SHA-1, SHA-256 and SHA-384. - * (Otherwise, computation of block_size needs to be adapted.) - */ -MBEDTLS_STATIC_TESTABLE int mbedtls_ssl_cf_hmac( - mbedtls_md_context_t *ctx, - const unsigned char *add_data, size_t add_data_len, - const unsigned char *data, size_t data_len_secret, - size_t min_data_len, size_t max_data_len, - unsigned char *output ) -{ - /* - * This function breaks the HMAC abstraction and uses the md_clone() - * extension to the MD API in order to get constant-flow behaviour. - * - * HMAC(msg) is defined as HASH(okey + HASH(ikey + msg)) where + means - * concatenation, and okey/ikey are the XOR of the key with some fixed bit - * patterns (see RFC 2104, sec. 2), which are stored in ctx->hmac_ctx. - * - * We'll first compute inner_hash = HASH(ikey + msg) by hashing up to - * minlen, then cloning the context, and for each byte up to maxlen - * finishing up the hash computation, keeping only the correct result. - * - * Then we only need to compute HASH(okey + inner_hash) and we're done. - */ - const mbedtls_md_type_t md_alg = mbedtls_md_get_type( ctx->md_info ); - /* TLS 1.0-1.2 only support SHA-384, SHA-256, SHA-1, MD-5, - * all of which have the same block size except SHA-384. */ - const size_t block_size = md_alg == MBEDTLS_MD_SHA384 ? 128 : 64; - const unsigned char * const ikey = ctx->hmac_ctx; - const unsigned char * const okey = ikey + block_size; - const size_t hash_size = mbedtls_md_get_size( ctx->md_info ); - - unsigned char aux_out[MBEDTLS_MD_MAX_SIZE]; - mbedtls_md_context_t aux; - size_t offset; - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - - mbedtls_md_init( &aux ); - -#define MD_CHK( func_call ) \ - do { \ - ret = (func_call); \ - if( ret != 0 ) \ - goto cleanup; \ - } while( 0 ) - - MD_CHK( mbedtls_md_setup( &aux, ctx->md_info, 0 ) ); - - /* After hmac_start() of hmac_reset(), ikey has already been hashed, - * so we can start directly with the message */ - MD_CHK( mbedtls_md_update( ctx, add_data, add_data_len ) ); - MD_CHK( mbedtls_md_update( ctx, data, min_data_len ) ); - - /* For each possible length, compute the hash up to that point */ - for( offset = min_data_len; offset <= max_data_len; offset++ ) - { - MD_CHK( mbedtls_md_clone( &aux, ctx ) ); - MD_CHK( mbedtls_md_finish( &aux, aux_out ) ); - /* Keep only the correct inner_hash in the output buffer */ - mbedtls_ssl_cf_memcpy_if_eq( output, aux_out, hash_size, - offset, data_len_secret ); - - if( offset < max_data_len ) - MD_CHK( mbedtls_md_update( ctx, data + offset, 1 ) ); - } - - /* The context needs to finish() before it starts() again */ - MD_CHK( mbedtls_md_finish( ctx, aux_out ) ); - - /* Now compute HASH(okey + inner_hash) */ - MD_CHK( mbedtls_md_starts( ctx ) ); - MD_CHK( mbedtls_md_update( ctx, okey, block_size ) ); - MD_CHK( mbedtls_md_update( ctx, output, hash_size ) ); - MD_CHK( mbedtls_md_finish( ctx, output ) ); - - /* Done, get ready for next time */ - MD_CHK( mbedtls_md_hmac_reset( ctx ) ); - -#undef MD_CHK - -cleanup: - mbedtls_md_free( &aux ); - return( ret ); -} - -/* - * Constant-flow memcpy from variable position in buffer. - * - functionally equivalent to memcpy(dst, src + offset_secret, len) - * - but with execution flow independent from the value of offset_secret. - */ -MBEDTLS_STATIC_TESTABLE void mbedtls_ssl_cf_memcpy_offset( - unsigned char *dst, - const unsigned char *src_base, - size_t offset_secret, - size_t offset_min, size_t offset_max, - size_t len ) -{ - size_t offset; - - for( offset = offset_min; offset <= offset_max; offset++ ) - { - mbedtls_ssl_cf_memcpy_if_eq( dst, src_base + offset, len, - offset, offset_secret ); - } -} -#endif /* MBEDTLS_SSL_SOME_SUITES_USE_TLS_CBC */ - -int mbedtls_ssl_decrypt_buf( mbedtls_ssl_context const *ssl, - mbedtls_ssl_transform *transform, - mbedtls_record *rec ) -{ - size_t olen; - mbedtls_cipher_mode_t mode; - int ret, auth_done = 0; -#if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC) - size_t padlen = 0, correct = 1; -#endif - unsigned char* data; - unsigned char add_data[13 + 1 + MBEDTLS_SSL_CID_IN_LEN_MAX ]; - size_t add_data_len; - -#if !defined(MBEDTLS_DEBUG_C) - ssl = NULL; /* make sure we don't use it except for debug */ - ((void) ssl); -#endif - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> decrypt buf" ) ); - if( rec == NULL || - rec->buf == NULL || - rec->buf_len < rec->data_offset || - rec->buf_len - rec->data_offset < rec->data_len ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad record structure provided to decrypt_buf" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - - data = rec->buf + rec->data_offset; - mode = mbedtls_cipher_get_cipher_mode( &transform->cipher_ctx_dec ); - -#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) - /* - * Match record's CID with incoming CID. - */ - if( rec->cid_len != transform->in_cid_len || - memcmp( rec->cid, transform->in_cid, rec->cid_len ) != 0 ) - { - return( MBEDTLS_ERR_SSL_UNEXPECTED_CID ); - } -#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ - -#if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER) - if( mode == MBEDTLS_MODE_STREAM ) - { - padlen = 0; - if( ( ret = mbedtls_cipher_crypt( &transform->cipher_ctx_dec, - transform->iv_dec, - transform->ivlen, - data, rec->data_len, - data, &olen ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_crypt", ret ); - return( ret ); - } - - if( rec->data_len != olen ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - } - else -#endif /* MBEDTLS_ARC4_C || MBEDTLS_CIPHER_NULL_CIPHER */ -#if defined(MBEDTLS_GCM_C) || \ - defined(MBEDTLS_CCM_C) || \ - defined(MBEDTLS_CHACHAPOLY_C) - if( mode == MBEDTLS_MODE_GCM || - mode == MBEDTLS_MODE_CCM || - mode == MBEDTLS_MODE_CHACHAPOLY ) - { - unsigned char iv[12]; - unsigned char *dynamic_iv; - size_t dynamic_iv_len; - - /* - * Extract dynamic part of nonce for AEAD decryption. - * - * Note: In the case of CCM and GCM in TLS 1.2, the dynamic - * part of the IV is prepended to the ciphertext and - * can be chosen freely - in particular, it need not - * agree with the record sequence number. - */ - dynamic_iv_len = sizeof( rec->ctr ); - if( ssl_transform_aead_dynamic_iv_is_explicit( transform ) == 1 ) - { - if( rec->data_len < dynamic_iv_len ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%" MBEDTLS_PRINTF_SIZET - " ) < explicit_iv_len (%" MBEDTLS_PRINTF_SIZET ") ", - rec->data_len, - dynamic_iv_len ) ); - return( MBEDTLS_ERR_SSL_INVALID_MAC ); - } - dynamic_iv = data; - - data += dynamic_iv_len; - rec->data_offset += dynamic_iv_len; - rec->data_len -= dynamic_iv_len; - } - else - { - dynamic_iv = rec->ctr; - } - - /* Check that there's space for the authentication tag. */ - if( rec->data_len < transform->taglen ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%" MBEDTLS_PRINTF_SIZET - ") < taglen (%" MBEDTLS_PRINTF_SIZET ") ", - rec->data_len, - transform->taglen ) ); - return( MBEDTLS_ERR_SSL_INVALID_MAC ); - } - rec->data_len -= transform->taglen; - - /* - * Prepare nonce from dynamic and static parts. - */ - ssl_build_record_nonce( iv, sizeof( iv ), - transform->iv_dec, - transform->fixed_ivlen, - dynamic_iv, - dynamic_iv_len ); - - /* - * Build additional data for AEAD encryption. - * This depends on the TLS version. - */ - ssl_extract_add_data_from_record( add_data, &add_data_len, rec, - transform->minor_ver ); - MBEDTLS_SSL_DEBUG_BUF( 4, "additional data used for AEAD", - add_data, add_data_len ); - - /* Because of the check above, we know that there are - * explicit_iv_len Bytes preceeding data, and taglen - * bytes following data + data_len. This justifies - * the debug message and the invocation of - * mbedtls_cipher_auth_decrypt() below. */ - - MBEDTLS_SSL_DEBUG_BUF( 4, "IV used", iv, transform->ivlen ); - MBEDTLS_SSL_DEBUG_BUF( 4, "TAG used", data + rec->data_len, - transform->taglen ); - - /* - * Decrypt and authenticate - */ - if( ( ret = mbedtls_cipher_auth_decrypt_ext( &transform->cipher_ctx_dec, - iv, transform->ivlen, - add_data, add_data_len, - data, rec->data_len + transform->taglen, /* src */ - data, rec->buf_len - (data - rec->buf), &olen, /* dst */ - transform->taglen ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_auth_decrypt", ret ); - - if( ret == MBEDTLS_ERR_CIPHER_AUTH_FAILED ) - return( MBEDTLS_ERR_SSL_INVALID_MAC ); - - return( ret ); - } - auth_done++; - - /* Double-check that AEAD decryption doesn't change content length. */ - if( olen != rec->data_len ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - } - else -#endif /* MBEDTLS_GCM_C || MBEDTLS_CCM_C */ -#if defined(MBEDTLS_SSL_SOME_SUITES_USE_CBC) - if( mode == MBEDTLS_MODE_CBC ) - { - size_t minlen = 0; - - /* - * Check immediate ciphertext sanity - */ -#if defined(MBEDTLS_SSL_PROTO_TLS1_1) || defined(MBEDTLS_SSL_PROTO_TLS1_2) - if( transform->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_2 ) - { - /* The ciphertext is prefixed with the CBC IV. */ - minlen += transform->ivlen; - } -#endif - - /* Size considerations: - * - * - The CBC cipher text must not be empty and hence - * at least of size transform->ivlen. - * - * Together with the potential IV-prefix, this explains - * the first of the two checks below. - * - * - The record must contain a MAC, either in plain or - * encrypted, depending on whether Encrypt-then-MAC - * is used or not. - * - If it is, the message contains the IV-prefix, - * the CBC ciphertext, and the MAC. - * - If it is not, the padded plaintext, and hence - * the CBC ciphertext, has at least length maclen + 1 - * because there is at least the padding length byte. - * - * As the CBC ciphertext is not empty, both cases give the - * lower bound minlen + maclen + 1 on the record size, which - * we test for in the second check below. - */ - if( rec->data_len < minlen + transform->ivlen || - rec->data_len < minlen + transform->maclen + 1 ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%" MBEDTLS_PRINTF_SIZET - ") < max( ivlen(%" MBEDTLS_PRINTF_SIZET - "), maclen (%" MBEDTLS_PRINTF_SIZET ") " - "+ 1 ) ( + expl IV )", rec->data_len, - transform->ivlen, - transform->maclen ) ); - return( MBEDTLS_ERR_SSL_INVALID_MAC ); - } - - /* - * Authenticate before decrypt if enabled - */ -#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) - if( transform->encrypt_then_mac == MBEDTLS_SSL_ETM_ENABLED ) - { - unsigned char mac_expect[MBEDTLS_SSL_MAC_ADD]; - - MBEDTLS_SSL_DEBUG_MSG( 3, ( "using encrypt then mac" ) ); - - /* Update data_len in tandem with add_data. - * - * The subtraction is safe because of the previous check - * data_len >= minlen + maclen + 1. - * - * Afterwards, we know that data + data_len is followed by at - * least maclen Bytes, which justifies the call to - * mbedtls_ssl_safer_memcmp() below. - * - * Further, we still know that data_len > minlen */ - rec->data_len -= transform->maclen; - ssl_extract_add_data_from_record( add_data, &add_data_len, rec, - transform->minor_ver ); - - /* Calculate expected MAC. */ - MBEDTLS_SSL_DEBUG_BUF( 4, "MAC'd meta-data", add_data, - add_data_len ); - mbedtls_md_hmac_update( &transform->md_ctx_dec, add_data, - add_data_len ); - mbedtls_md_hmac_update( &transform->md_ctx_dec, - data, rec->data_len ); - mbedtls_md_hmac_finish( &transform->md_ctx_dec, mac_expect ); - mbedtls_md_hmac_reset( &transform->md_ctx_dec ); - - MBEDTLS_SSL_DEBUG_BUF( 4, "message mac", data + rec->data_len, - transform->maclen ); - MBEDTLS_SSL_DEBUG_BUF( 4, "expected mac", mac_expect, - transform->maclen ); - - /* Compare expected MAC with MAC at the end of the record. */ - if( mbedtls_ssl_safer_memcmp( data + rec->data_len, mac_expect, - transform->maclen ) != 0 ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "message mac does not match" ) ); - return( MBEDTLS_ERR_SSL_INVALID_MAC ); - } - auth_done++; - } -#endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */ - - /* - * Check length sanity - */ - - /* We know from above that data_len > minlen >= 0, - * so the following check in particular implies that - * data_len >= minlen + ivlen ( = minlen or 2 * minlen ). */ - if( rec->data_len % transform->ivlen != 0 ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%" MBEDTLS_PRINTF_SIZET - ") %% ivlen (%" MBEDTLS_PRINTF_SIZET ") != 0", - rec->data_len, transform->ivlen ) ); - return( MBEDTLS_ERR_SSL_INVALID_MAC ); - } - -#if defined(MBEDTLS_SSL_PROTO_TLS1_1) || defined(MBEDTLS_SSL_PROTO_TLS1_2) - /* - * Initialize for prepended IV for block cipher in TLS v1.1 and up - */ - if( transform->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_2 ) - { - /* Safe because data_len >= minlen + ivlen = 2 * ivlen. */ - memcpy( transform->iv_dec, data, transform->ivlen ); - - data += transform->ivlen; - rec->data_offset += transform->ivlen; - rec->data_len -= transform->ivlen; - } -#endif /* MBEDTLS_SSL_PROTO_TLS1_1 || MBEDTLS_SSL_PROTO_TLS1_2 */ - - /* We still have data_len % ivlen == 0 and data_len >= ivlen here. */ - - if( ( ret = mbedtls_cipher_crypt( &transform->cipher_ctx_dec, - transform->iv_dec, transform->ivlen, - data, rec->data_len, data, &olen ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_crypt", ret ); - return( ret ); - } - - /* Double-check that length hasn't changed during decryption. */ - if( rec->data_len != olen ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - -#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) - if( transform->minor_ver < MBEDTLS_SSL_MINOR_VERSION_2 ) - { - /* - * Save IV in SSL3 and TLS1, where CBC decryption of consecutive - * records is equivalent to CBC decryption of the concatenation - * of the records; in other words, IVs are maintained across - * record decryptions. - */ - memcpy( transform->iv_dec, transform->cipher_ctx_dec.iv, - transform->ivlen ); - } -#endif - - /* Safe since data_len >= minlen + maclen + 1, so after having - * subtracted at most minlen and maclen up to this point, - * data_len > 0 (because of data_len % ivlen == 0, it's actually - * >= ivlen ). */ - padlen = data[rec->data_len - 1]; - - if( auth_done == 1 ) - { - const size_t mask = mbedtls_ssl_cf_mask_ge( - rec->data_len, - padlen + 1 ); - correct &= mask; - padlen &= mask; - } - else - { -#if defined(MBEDTLS_SSL_DEBUG_ALL) - if( rec->data_len < transform->maclen + padlen + 1 ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%" MBEDTLS_PRINTF_SIZET - ") < maclen (%" MBEDTLS_PRINTF_SIZET - ") + padlen (%" MBEDTLS_PRINTF_SIZET ")", - rec->data_len, - transform->maclen, - padlen + 1 ) ); - } -#endif - - const size_t mask = mbedtls_ssl_cf_mask_ge( - rec->data_len, - transform->maclen + padlen + 1 ); - correct &= mask; - padlen &= mask; - } - - padlen++; - - /* Regardless of the validity of the padding, - * we have data_len >= padlen here. */ - -#if defined(MBEDTLS_SSL_PROTO_SSL3) - if( transform->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ) - { - /* This is the SSL 3.0 path, we don't have to worry about Lucky - * 13, because there's a strictly worse padding attack built in - * the protocol (known as part of POODLE), so we don't care if the - * code is not constant-time, in particular branches are OK. */ - if( padlen > transform->ivlen ) - { -#if defined(MBEDTLS_SSL_DEBUG_ALL) - MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad padding length: is %" MBEDTLS_PRINTF_SIZET ", " - "should be no more than %" MBEDTLS_PRINTF_SIZET, - padlen, transform->ivlen ) ); -#endif - correct = 0; - } - } - else -#endif /* MBEDTLS_SSL_PROTO_SSL3 */ -#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \ - defined(MBEDTLS_SSL_PROTO_TLS1_2) - if( transform->minor_ver > MBEDTLS_SSL_MINOR_VERSION_0 ) - { - /* The padding check involves a series of up to 256 - * consecutive memory reads at the end of the record - * plaintext buffer. In order to hide the length and - * validity of the padding, always perform exactly - * `min(256,plaintext_len)` reads (but take into account - * only the last `padlen` bytes for the padding check). */ - size_t pad_count = 0; - volatile unsigned char* const check = data; - - /* Index of first padding byte; it has been ensured above - * that the subtraction is safe. */ - size_t const padding_idx = rec->data_len - padlen; - size_t const num_checks = rec->data_len <= 256 ? rec->data_len : 256; - size_t const start_idx = rec->data_len - num_checks; - size_t idx; - - for( idx = start_idx; idx < rec->data_len; idx++ ) - { - /* pad_count += (idx >= padding_idx) && - * (check[idx] == padlen - 1); - */ - const size_t mask = mbedtls_ssl_cf_mask_ge( idx, padding_idx ); - const size_t equal = mbedtls_ssl_cf_bool_eq( check[idx], - padlen - 1 ); - pad_count += mask & equal; - } - correct &= mbedtls_ssl_cf_bool_eq( pad_count, padlen ); - -#if defined(MBEDTLS_SSL_DEBUG_ALL) - if( padlen > 0 && correct == 0 ) - MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad padding byte detected" ) ); -#endif - padlen &= mbedtls_ssl_cf_mask_from_bit( correct ); - } - else -#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \ - MBEDTLS_SSL_PROTO_TLS1_2 */ - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - - /* If the padding was found to be invalid, padlen == 0 - * and the subtraction is safe. If the padding was found valid, - * padlen hasn't been changed and the previous assertion - * data_len >= padlen still holds. */ - rec->data_len -= padlen; - } - else -#endif /* MBEDTLS_SSL_SOME_SUITES_USE_CBC */ - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - -#if defined(MBEDTLS_SSL_DEBUG_ALL) - MBEDTLS_SSL_DEBUG_BUF( 4, "raw buffer after decryption", - data, rec->data_len ); -#endif - - /* - * Authenticate if not done yet. - * Compute the MAC regardless of the padding result (RFC4346, CBCTIME). - */ -#if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC) - if( auth_done == 0 ) - { - unsigned char mac_expect[MBEDTLS_SSL_MAC_ADD]; - unsigned char mac_peer[MBEDTLS_SSL_MAC_ADD]; - - /* If the initial value of padlen was such that - * data_len < maclen + padlen + 1, then padlen - * got reset to 1, and the initial check - * data_len >= minlen + maclen + 1 - * guarantees that at this point we still - * have at least data_len >= maclen. - * - * If the initial value of padlen was such that - * data_len >= maclen + padlen + 1, then we have - * subtracted either padlen + 1 (if the padding was correct) - * or 0 (if the padding was incorrect) since then, - * hence data_len >= maclen in any case. - */ - rec->data_len -= transform->maclen; - ssl_extract_add_data_from_record( add_data, &add_data_len, rec, - transform->minor_ver ); - -#if defined(MBEDTLS_SSL_PROTO_SSL3) - if( transform->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ) - { - ssl_mac( &transform->md_ctx_dec, - transform->mac_dec, - data, rec->data_len, - rec->ctr, rec->type, - mac_expect ); - memcpy( mac_peer, data + rec->data_len, transform->maclen ); - } - else -#endif /* MBEDTLS_SSL_PROTO_SSL3 */ -#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \ - defined(MBEDTLS_SSL_PROTO_TLS1_2) - if( transform->minor_ver > MBEDTLS_SSL_MINOR_VERSION_0 ) - { - /* - * The next two sizes are the minimum and maximum values of - * data_len over all padlen values. - * - * They're independent of padlen, since we previously did - * data_len -= padlen. - * - * Note that max_len + maclen is never more than the buffer - * length, as we previously did in_msglen -= maclen too. - */ - const size_t max_len = rec->data_len + padlen; - const size_t min_len = ( max_len > 256 ) ? max_len - 256 : 0; - - ret = mbedtls_ssl_cf_hmac( &transform->md_ctx_dec, - add_data, add_data_len, - data, rec->data_len, min_len, max_len, - mac_expect ); - if( ret != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_cf_hmac", ret ); - return( ret ); - } - - mbedtls_ssl_cf_memcpy_offset( mac_peer, data, - rec->data_len, - min_len, max_len, - transform->maclen ); - } - else -#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \ - MBEDTLS_SSL_PROTO_TLS1_2 */ - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - -#if defined(MBEDTLS_SSL_DEBUG_ALL) - MBEDTLS_SSL_DEBUG_BUF( 4, "expected mac", mac_expect, transform->maclen ); - MBEDTLS_SSL_DEBUG_BUF( 4, "message mac", mac_peer, transform->maclen ); -#endif - - if( mbedtls_ssl_safer_memcmp( mac_peer, mac_expect, - transform->maclen ) != 0 ) - { -#if defined(MBEDTLS_SSL_DEBUG_ALL) - MBEDTLS_SSL_DEBUG_MSG( 1, ( "message mac does not match" ) ); -#endif - correct = 0; - } - auth_done++; - } - - /* - * Finally check the correct flag - */ - if( correct == 0 ) - return( MBEDTLS_ERR_SSL_INVALID_MAC ); -#endif /* MBEDTLS_SSL_SOME_MODES_USE_MAC */ - - /* Make extra sure authentication was performed, exactly once */ - if( auth_done != 1 ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - -#if defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL) - if( transform->minor_ver == MBEDTLS_SSL_MINOR_VERSION_4 ) - { - /* Remove inner padding and infer true content type. */ - ret = ssl_parse_inner_plaintext( data, &rec->data_len, - &rec->type ); - - if( ret != 0 ) - return( MBEDTLS_ERR_SSL_INVALID_RECORD ); - } -#endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */ - -#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) - if( rec->cid_len != 0 ) - { - ret = ssl_parse_inner_plaintext( data, &rec->data_len, - &rec->type ); - if( ret != 0 ) - return( MBEDTLS_ERR_SSL_INVALID_RECORD ); - } -#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= decrypt buf" ) ); - - return( 0 ); -} - -#undef MAC_NONE -#undef MAC_PLAINTEXT -#undef MAC_CIPHERTEXT - -#if defined(MBEDTLS_ZLIB_SUPPORT) -/* - * Compression/decompression functions - */ -static int ssl_compress_buf( mbedtls_ssl_context *ssl ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - unsigned char *msg_post = ssl->out_msg; - ptrdiff_t bytes_written = ssl->out_msg - ssl->out_buf; - size_t len_pre = ssl->out_msglen; - unsigned char *msg_pre = ssl->compress_buf; -#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH) - size_t out_buf_len = ssl->out_buf_len; -#else - size_t out_buf_len = MBEDTLS_SSL_OUT_BUFFER_LEN; -#endif - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> compress buf" ) ); - - if( len_pre == 0 ) - return( 0 ); - - memcpy( msg_pre, ssl->out_msg, len_pre ); - - MBEDTLS_SSL_DEBUG_MSG( 3, ( "before compression: msglen = %" MBEDTLS_PRINTF_SIZET ", ", - ssl->out_msglen ) ); - - MBEDTLS_SSL_DEBUG_BUF( 4, "before compression: output payload", - ssl->out_msg, ssl->out_msglen ); - - ssl->transform_out->ctx_deflate.next_in = msg_pre; - ssl->transform_out->ctx_deflate.avail_in = len_pre; - ssl->transform_out->ctx_deflate.next_out = msg_post; - ssl->transform_out->ctx_deflate.avail_out = out_buf_len - bytes_written; - - ret = deflate( &ssl->transform_out->ctx_deflate, Z_SYNC_FLUSH ); - if( ret != Z_OK ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "failed to perform compression (%d)", ret ) ); - return( MBEDTLS_ERR_SSL_COMPRESSION_FAILED ); - } - - ssl->out_msglen = out_buf_len - - ssl->transform_out->ctx_deflate.avail_out - bytes_written; - - MBEDTLS_SSL_DEBUG_MSG( 3, ( "after compression: msglen = %" MBEDTLS_PRINTF_SIZET ", ", - ssl->out_msglen ) ); - - MBEDTLS_SSL_DEBUG_BUF( 4, "after compression: output payload", - ssl->out_msg, ssl->out_msglen ); - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= compress buf" ) ); - - return( 0 ); -} - -static int ssl_decompress_buf( mbedtls_ssl_context *ssl ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - unsigned char *msg_post = ssl->in_msg; - ptrdiff_t header_bytes = ssl->in_msg - ssl->in_buf; - size_t len_pre = ssl->in_msglen; - unsigned char *msg_pre = ssl->compress_buf; -#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH) - size_t in_buf_len = ssl->in_buf_len; -#else - size_t in_buf_len = MBEDTLS_SSL_IN_BUFFER_LEN; -#endif - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> decompress buf" ) ); - - if( len_pre == 0 ) - return( 0 ); - - memcpy( msg_pre, ssl->in_msg, len_pre ); - - MBEDTLS_SSL_DEBUG_MSG( 3, ( "before decompression: msglen = %" MBEDTLS_PRINTF_SIZET ", ", - ssl->in_msglen ) ); - - MBEDTLS_SSL_DEBUG_BUF( 4, "before decompression: input payload", - ssl->in_msg, ssl->in_msglen ); - - ssl->transform_in->ctx_inflate.next_in = msg_pre; - ssl->transform_in->ctx_inflate.avail_in = len_pre; - ssl->transform_in->ctx_inflate.next_out = msg_post; - ssl->transform_in->ctx_inflate.avail_out = in_buf_len - header_bytes; - - ret = inflate( &ssl->transform_in->ctx_inflate, Z_SYNC_FLUSH ); - if( ret != Z_OK ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "failed to perform decompression (%d)", ret ) ); - return( MBEDTLS_ERR_SSL_COMPRESSION_FAILED ); - } - - ssl->in_msglen = in_buf_len - - ssl->transform_in->ctx_inflate.avail_out - header_bytes; - - MBEDTLS_SSL_DEBUG_MSG( 3, ( "after decompression: msglen = %" MBEDTLS_PRINTF_SIZET ", ", - ssl->in_msglen ) ); - - MBEDTLS_SSL_DEBUG_BUF( 4, "after decompression: input payload", - ssl->in_msg, ssl->in_msglen ); - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= decompress buf" ) ); - - return( 0 ); -} -#endif /* MBEDTLS_ZLIB_SUPPORT */ - -/* - * Fill the input message buffer by appending data to it. - * The amount of data already fetched is in ssl->in_left. - * - * If we return 0, is it guaranteed that (at least) nb_want bytes are - * available (from this read and/or a previous one). Otherwise, an error code - * is returned (possibly EOF or WANT_READ). - * - * With stream transport (TLS) on success ssl->in_left == nb_want, but - * with datagram transport (DTLS) on success ssl->in_left >= nb_want, - * since we always read a whole datagram at once. - * - * For DTLS, it is up to the caller to set ssl->next_record_offset when - * they're done reading a record. - */ -int mbedtls_ssl_fetch_input( mbedtls_ssl_context *ssl, size_t nb_want ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - size_t len; -#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH) - size_t in_buf_len = ssl->in_buf_len; -#else - size_t in_buf_len = MBEDTLS_SSL_IN_BUFFER_LEN; -#endif - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> fetch input" ) ); - - if( ssl->f_recv == NULL && ssl->f_recv_timeout == NULL ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "Bad usage of mbedtls_ssl_set_bio() " - "or mbedtls_ssl_set_bio()" ) ); - return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); - } - - if( nb_want > in_buf_len - (size_t)( ssl->in_hdr - ssl->in_buf ) ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "requesting more data than fits" ) ); - return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); - } - -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { - uint32_t timeout; - - /* - * The point is, we need to always read a full datagram at once, so we - * sometimes read more then requested, and handle the additional data. - * It could be the rest of the current record (while fetching the - * header) and/or some other records in the same datagram. - */ - - /* - * Move to the next record in the already read datagram if applicable - */ - if( ssl->next_record_offset != 0 ) - { - if( ssl->in_left < ssl->next_record_offset ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - - ssl->in_left -= ssl->next_record_offset; - - if( ssl->in_left != 0 ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "next record in same datagram, offset: %" - MBEDTLS_PRINTF_SIZET, - ssl->next_record_offset ) ); - memmove( ssl->in_hdr, - ssl->in_hdr + ssl->next_record_offset, - ssl->in_left ); - } - - ssl->next_record_offset = 0; - } - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "in_left: %" MBEDTLS_PRINTF_SIZET - ", nb_want: %" MBEDTLS_PRINTF_SIZET, - ssl->in_left, nb_want ) ); - - /* - * Done if we already have enough data. - */ - if( nb_want <= ssl->in_left) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= fetch input" ) ); - return( 0 ); - } - - /* - * A record can't be split across datagrams. If we need to read but - * are not at the beginning of a new record, the caller did something - * wrong. - */ - if( ssl->in_left != 0 ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - - /* - * Don't even try to read if time's out already. - * This avoids by-passing the timer when repeatedly receiving messages - * that will end up being dropped. - */ - if( mbedtls_ssl_check_timer( ssl ) != 0 ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "timer has expired" ) ); - ret = MBEDTLS_ERR_SSL_TIMEOUT; - } - else - { - len = in_buf_len - ( ssl->in_hdr - ssl->in_buf ); - - if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER ) - timeout = ssl->handshake->retransmit_timeout; - else - timeout = ssl->conf->read_timeout; - - MBEDTLS_SSL_DEBUG_MSG( 3, ( "f_recv_timeout: %lu ms", (unsigned long) timeout ) ); - - if( ssl->f_recv_timeout != NULL ) - ret = ssl->f_recv_timeout( ssl->p_bio, ssl->in_hdr, len, - timeout ); - else - ret = ssl->f_recv( ssl->p_bio, ssl->in_hdr, len ); - - MBEDTLS_SSL_DEBUG_RET( 2, "ssl->f_recv(_timeout)", ret ); - - if( ret == 0 ) - return( MBEDTLS_ERR_SSL_CONN_EOF ); - } - - if( ret == MBEDTLS_ERR_SSL_TIMEOUT ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "timeout" ) ); - mbedtls_ssl_set_timer( ssl, 0 ); - - if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER ) - { - if( ssl_double_retransmit_timeout( ssl ) != 0 ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "handshake timeout" ) ); - return( MBEDTLS_ERR_SSL_TIMEOUT ); - } - - if( ( ret = mbedtls_ssl_resend( ssl ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_resend", ret ); - return( ret ); - } - - return( MBEDTLS_ERR_SSL_WANT_READ ); - } -#if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_RENEGOTIATION) - else if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER && - ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_PENDING ) - { - if( ( ret = mbedtls_ssl_resend_hello_request( ssl ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_resend_hello_request", - ret ); - return( ret ); - } - - return( MBEDTLS_ERR_SSL_WANT_READ ); - } -#endif /* MBEDTLS_SSL_SRV_C && MBEDTLS_SSL_RENEGOTIATION */ - } - - if( ret < 0 ) - return( ret ); - - ssl->in_left = ret; - } - else -#endif - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "in_left: %" MBEDTLS_PRINTF_SIZET - ", nb_want: %" MBEDTLS_PRINTF_SIZET, - ssl->in_left, nb_want ) ); - - while( ssl->in_left < nb_want ) - { - len = nb_want - ssl->in_left; - - if( mbedtls_ssl_check_timer( ssl ) != 0 ) - ret = MBEDTLS_ERR_SSL_TIMEOUT; - else - { - if( ssl->f_recv_timeout != NULL ) - { - ret = ssl->f_recv_timeout( ssl->p_bio, - ssl->in_hdr + ssl->in_left, len, - ssl->conf->read_timeout ); - } - else - { - ret = ssl->f_recv( ssl->p_bio, - ssl->in_hdr + ssl->in_left, len ); - } - } - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "in_left: %" MBEDTLS_PRINTF_SIZET - ", nb_want: %" MBEDTLS_PRINTF_SIZET, - ssl->in_left, nb_want ) ); - MBEDTLS_SSL_DEBUG_RET( 2, "ssl->f_recv(_timeout)", ret ); - - if( ret == 0 ) - return( MBEDTLS_ERR_SSL_CONN_EOF ); - - if( ret < 0 ) - return( ret ); - - if ( (size_t)ret > len || ( INT_MAX > SIZE_MAX && ret > (int)SIZE_MAX ) ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, - ( "f_recv returned %d bytes but only %" MBEDTLS_PRINTF_SIZET " were requested", - ret, len ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - - ssl->in_left += ret; - } - } - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= fetch input" ) ); - - return( 0 ); -} - -/* - * Flush any data not yet written - */ -int mbedtls_ssl_flush_output( mbedtls_ssl_context *ssl ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - unsigned char *buf; - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> flush output" ) ); - - if( ssl->f_send == NULL ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "Bad usage of mbedtls_ssl_set_bio() " - "or mbedtls_ssl_set_bio()" ) ); - return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); - } - - /* Avoid incrementing counter if data is flushed */ - if( ssl->out_left == 0 ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= flush output" ) ); - return( 0 ); - } - - while( ssl->out_left > 0 ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "message length: %" MBEDTLS_PRINTF_SIZET - ", out_left: %" MBEDTLS_PRINTF_SIZET, - mbedtls_ssl_out_hdr_len( ssl ) + ssl->out_msglen, ssl->out_left ) ); - - buf = ssl->out_hdr - ssl->out_left; - ret = ssl->f_send( ssl->p_bio, buf, ssl->out_left ); - - MBEDTLS_SSL_DEBUG_RET( 2, "ssl->f_send", ret ); - - if( ret <= 0 ) - return( ret ); - - if( (size_t)ret > ssl->out_left || ( INT_MAX > SIZE_MAX && ret > (int)SIZE_MAX ) ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, - ( "f_send returned %d bytes but only %" MBEDTLS_PRINTF_SIZET " bytes were sent", - ret, ssl->out_left ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - - ssl->out_left -= ret; - } - -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { - ssl->out_hdr = ssl->out_buf; - } - else -#endif - { - ssl->out_hdr = ssl->out_buf + 8; - } - mbedtls_ssl_update_out_pointers( ssl, ssl->transform_out ); - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= flush output" ) ); - - return( 0 ); -} - -/* - * Functions to handle the DTLS retransmission state machine - */ -#if defined(MBEDTLS_SSL_PROTO_DTLS) -/* - * Append current handshake message to current outgoing flight - */ -static int ssl_flight_append( mbedtls_ssl_context *ssl ) -{ - mbedtls_ssl_flight_item *msg; - MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> ssl_flight_append" ) ); - MBEDTLS_SSL_DEBUG_BUF( 4, "message appended to flight", - ssl->out_msg, ssl->out_msglen ); - - /* Allocate space for current message */ - if( ( msg = mbedtls_calloc( 1, sizeof( mbedtls_ssl_flight_item ) ) ) == NULL ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc %" MBEDTLS_PRINTF_SIZET " bytes failed", - sizeof( mbedtls_ssl_flight_item ) ) ); - return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); - } - - if( ( msg->p = mbedtls_calloc( 1, ssl->out_msglen ) ) == NULL ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc %" MBEDTLS_PRINTF_SIZET " bytes failed", - ssl->out_msglen ) ); - mbedtls_free( msg ); - return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); - } - - /* Copy current handshake message with headers */ - memcpy( msg->p, ssl->out_msg, ssl->out_msglen ); - msg->len = ssl->out_msglen; - msg->type = ssl->out_msgtype; - msg->next = NULL; - - /* Append to the current flight */ - if( ssl->handshake->flight == NULL ) - ssl->handshake->flight = msg; - else - { - mbedtls_ssl_flight_item *cur = ssl->handshake->flight; - while( cur->next != NULL ) - cur = cur->next; - cur->next = msg; - } - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= ssl_flight_append" ) ); - return( 0 ); -} - -/* - * Free the current flight of handshake messages - */ -void mbedtls_ssl_flight_free( mbedtls_ssl_flight_item *flight ) -{ - mbedtls_ssl_flight_item *cur = flight; - mbedtls_ssl_flight_item *next; - - while( cur != NULL ) - { - next = cur->next; - - mbedtls_free( cur->p ); - mbedtls_free( cur ); - - cur = next; - } -} - -/* - * Swap transform_out and out_ctr with the alternative ones - */ -static int ssl_swap_epochs( mbedtls_ssl_context *ssl ) -{ - mbedtls_ssl_transform *tmp_transform; - unsigned char tmp_out_ctr[8]; - - if( ssl->transform_out == ssl->handshake->alt_transform_out ) - { - MBEDTLS_SSL_DEBUG_MSG( 3, ( "skip swap epochs" ) ); - return( 0 ); - } - - MBEDTLS_SSL_DEBUG_MSG( 3, ( "swap epochs" ) ); - - /* Swap transforms */ - tmp_transform = ssl->transform_out; - ssl->transform_out = ssl->handshake->alt_transform_out; - ssl->handshake->alt_transform_out = tmp_transform; - - /* Swap epoch + sequence_number */ - memcpy( tmp_out_ctr, ssl->cur_out_ctr, 8 ); - memcpy( ssl->cur_out_ctr, ssl->handshake->alt_out_ctr, 8 ); - memcpy( ssl->handshake->alt_out_ctr, tmp_out_ctr, 8 ); - - /* Adjust to the newly activated transform */ - mbedtls_ssl_update_out_pointers( ssl, ssl->transform_out ); - -#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL) - if( mbedtls_ssl_hw_record_activate != NULL ) - { - int ret = mbedtls_ssl_hw_record_activate( ssl, MBEDTLS_SSL_CHANNEL_OUTBOUND ); - if( ret != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_activate", ret ); - return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED ); - } - } -#endif - - return( 0 ); -} - -/* - * Retransmit the current flight of messages. - */ -int mbedtls_ssl_resend( mbedtls_ssl_context *ssl ) -{ - int ret = 0; - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> mbedtls_ssl_resend" ) ); - - ret = mbedtls_ssl_flight_transmit( ssl ); - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= mbedtls_ssl_resend" ) ); - - return( ret ); -} - -/* - * Transmit or retransmit the current flight of messages. - * - * Need to remember the current message in case flush_output returns - * WANT_WRITE, causing us to exit this function and come back later. - * This function must be called until state is no longer SENDING. - */ -int mbedtls_ssl_flight_transmit( mbedtls_ssl_context *ssl ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> mbedtls_ssl_flight_transmit" ) ); - - if( ssl->handshake->retransmit_state != MBEDTLS_SSL_RETRANS_SENDING ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "initialise flight transmission" ) ); - - ssl->handshake->cur_msg = ssl->handshake->flight; - ssl->handshake->cur_msg_p = ssl->handshake->flight->p + 12; - ret = ssl_swap_epochs( ssl ); - if( ret != 0 ) - return( ret ); - - ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_SENDING; - } - - while( ssl->handshake->cur_msg != NULL ) - { - size_t max_frag_len; - const mbedtls_ssl_flight_item * const cur = ssl->handshake->cur_msg; - - int const is_finished = - ( cur->type == MBEDTLS_SSL_MSG_HANDSHAKE && - cur->p[0] == MBEDTLS_SSL_HS_FINISHED ); - - uint8_t const force_flush = ssl->disable_datagram_packing == 1 ? - SSL_FORCE_FLUSH : SSL_DONT_FORCE_FLUSH; - - /* Swap epochs before sending Finished: we can't do it after - * sending ChangeCipherSpec, in case write returns WANT_READ. - * Must be done before copying, may change out_msg pointer */ - if( is_finished && ssl->handshake->cur_msg_p == ( cur->p + 12 ) ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "swap epochs to send finished message" ) ); - ret = ssl_swap_epochs( ssl ); - if( ret != 0 ) - return( ret ); - } - - ret = ssl_get_remaining_payload_in_datagram( ssl ); - if( ret < 0 ) - return( ret ); - max_frag_len = (size_t) ret; - - /* CCS is copied as is, while HS messages may need fragmentation */ - if( cur->type == MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC ) - { - if( max_frag_len == 0 ) - { - if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 ) - return( ret ); - - continue; - } - - memcpy( ssl->out_msg, cur->p, cur->len ); - ssl->out_msglen = cur->len; - ssl->out_msgtype = cur->type; - - /* Update position inside current message */ - ssl->handshake->cur_msg_p += cur->len; - } - else - { - const unsigned char * const p = ssl->handshake->cur_msg_p; - const size_t hs_len = cur->len - 12; - const size_t frag_off = p - ( cur->p + 12 ); - const size_t rem_len = hs_len - frag_off; - size_t cur_hs_frag_len, max_hs_frag_len; - - if( ( max_frag_len < 12 ) || ( max_frag_len == 12 && hs_len != 0 ) ) - { - if( is_finished ) - { - ret = ssl_swap_epochs( ssl ); - if( ret != 0 ) - return( ret ); - } - - if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 ) - return( ret ); - - continue; - } - max_hs_frag_len = max_frag_len - 12; - - cur_hs_frag_len = rem_len > max_hs_frag_len ? - max_hs_frag_len : rem_len; - - if( frag_off == 0 && cur_hs_frag_len != hs_len ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "fragmenting handshake message (%u > %u)", - (unsigned) cur_hs_frag_len, - (unsigned) max_hs_frag_len ) ); - } - - /* Messages are stored with handshake headers as if not fragmented, - * copy beginning of headers then fill fragmentation fields. - * Handshake headers: type(1) len(3) seq(2) f_off(3) f_len(3) */ - memcpy( ssl->out_msg, cur->p, 6 ); - - ssl->out_msg[6] = ( ( frag_off >> 16 ) & 0xff ); - ssl->out_msg[7] = ( ( frag_off >> 8 ) & 0xff ); - ssl->out_msg[8] = ( ( frag_off ) & 0xff ); - - ssl->out_msg[ 9] = ( ( cur_hs_frag_len >> 16 ) & 0xff ); - ssl->out_msg[10] = ( ( cur_hs_frag_len >> 8 ) & 0xff ); - ssl->out_msg[11] = ( ( cur_hs_frag_len ) & 0xff ); - - MBEDTLS_SSL_DEBUG_BUF( 3, "handshake header", ssl->out_msg, 12 ); - - /* Copy the handshake message content and set records fields */ - memcpy( ssl->out_msg + 12, p, cur_hs_frag_len ); - ssl->out_msglen = cur_hs_frag_len + 12; - ssl->out_msgtype = cur->type; - - /* Update position inside current message */ - ssl->handshake->cur_msg_p += cur_hs_frag_len; - } - - /* If done with the current message move to the next one if any */ - if( ssl->handshake->cur_msg_p >= cur->p + cur->len ) - { - if( cur->next != NULL ) - { - ssl->handshake->cur_msg = cur->next; - ssl->handshake->cur_msg_p = cur->next->p + 12; - } - else - { - ssl->handshake->cur_msg = NULL; - ssl->handshake->cur_msg_p = NULL; - } - } - - /* Actually send the message out */ - if( ( ret = mbedtls_ssl_write_record( ssl, force_flush ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret ); - return( ret ); - } - } - - if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 ) - return( ret ); - - /* Update state and set timer */ - if( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER ) - ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_FINISHED; - else - { - ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_WAITING; - mbedtls_ssl_set_timer( ssl, ssl->handshake->retransmit_timeout ); - } - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= mbedtls_ssl_flight_transmit" ) ); - - return( 0 ); -} - -/* - * To be called when the last message of an incoming flight is received. - */ -void mbedtls_ssl_recv_flight_completed( mbedtls_ssl_context *ssl ) -{ - /* We won't need to resend that one any more */ - mbedtls_ssl_flight_free( ssl->handshake->flight ); - ssl->handshake->flight = NULL; - ssl->handshake->cur_msg = NULL; - - /* The next incoming flight will start with this msg_seq */ - ssl->handshake->in_flight_start_seq = ssl->handshake->in_msg_seq; - - /* We don't want to remember CCS's across flight boundaries. */ - ssl->handshake->buffering.seen_ccs = 0; - - /* Clear future message buffering structure. */ - mbedtls_ssl_buffering_free( ssl ); - - /* Cancel timer */ - mbedtls_ssl_set_timer( ssl, 0 ); - - if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE && - ssl->in_msg[0] == MBEDTLS_SSL_HS_FINISHED ) - { - ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_FINISHED; - } - else - ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_PREPARING; -} - -/* - * To be called when the last message of an outgoing flight is send. - */ -void mbedtls_ssl_send_flight_completed( mbedtls_ssl_context *ssl ) -{ - ssl_reset_retransmit_timeout( ssl ); - mbedtls_ssl_set_timer( ssl, ssl->handshake->retransmit_timeout ); - - if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE && - ssl->in_msg[0] == MBEDTLS_SSL_HS_FINISHED ) - { - ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_FINISHED; - } - else - ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_WAITING; -} -#endif /* MBEDTLS_SSL_PROTO_DTLS */ - -/* - * Handshake layer functions - */ - -/* - * Write (DTLS: or queue) current handshake (including CCS) message. - * - * - fill in handshake headers - * - update handshake checksum - * - DTLS: save message for resending - * - then pass to the record layer - * - * DTLS: except for HelloRequest, messages are only queued, and will only be - * actually sent when calling flight_transmit() or resend(). - * - * Inputs: - * - ssl->out_msglen: 4 + actual handshake message len - * (4 is the size of handshake headers for TLS) - * - ssl->out_msg[0]: the handshake type (ClientHello, ServerHello, etc) - * - ssl->out_msg + 4: the handshake message body - * - * Outputs, ie state before passing to flight_append() or write_record(): - * - ssl->out_msglen: the length of the record contents - * (including handshake headers but excluding record headers) - * - ssl->out_msg: the record contents (handshake headers + content) - */ -int mbedtls_ssl_write_handshake_msg( mbedtls_ssl_context *ssl ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - const size_t hs_len = ssl->out_msglen - 4; - const unsigned char hs_type = ssl->out_msg[0]; - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write handshake message" ) ); - - /* - * Sanity checks - */ - if( ssl->out_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE && - ssl->out_msgtype != MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC ) - { - /* In SSLv3, the client might send a NoCertificate alert. */ -#if defined(MBEDTLS_SSL_PROTO_SSL3) && defined(MBEDTLS_SSL_CLI_C) - if( ! ( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 && - ssl->out_msgtype == MBEDTLS_SSL_MSG_ALERT && - ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT ) ) -#endif /* MBEDTLS_SSL_PROTO_SSL3 && MBEDTLS_SSL_SRV_C */ - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - } - - /* Whenever we send anything different from a - * HelloRequest we should be in a handshake - double check. */ - if( ! ( ssl->out_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE && - hs_type == MBEDTLS_SSL_HS_HELLO_REQUEST ) && - ssl->handshake == NULL ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && - ssl->handshake != NULL && - ssl->handshake->retransmit_state == MBEDTLS_SSL_RETRANS_SENDING ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } -#endif - - /* Double-check that we did not exceed the bounds - * of the outgoing record buffer. - * This should never fail as the various message - * writing functions must obey the bounds of the - * outgoing record buffer, but better be safe. - * - * Note: We deliberately do not check for the MTU or MFL here. - */ - if( ssl->out_msglen > MBEDTLS_SSL_OUT_CONTENT_LEN ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "Record too large: " - "size %" MBEDTLS_PRINTF_SIZET - ", maximum %" MBEDTLS_PRINTF_SIZET, - ssl->out_msglen, - (size_t) MBEDTLS_SSL_OUT_CONTENT_LEN ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - - /* - * Fill handshake headers - */ - if( ssl->out_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE ) - { - ssl->out_msg[1] = (unsigned char)( hs_len >> 16 ); - ssl->out_msg[2] = (unsigned char)( hs_len >> 8 ); - ssl->out_msg[3] = (unsigned char)( hs_len ); - - /* - * DTLS has additional fields in the Handshake layer, - * between the length field and the actual payload: - * uint16 message_seq; - * uint24 fragment_offset; - * uint24 fragment_length; - */ -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { - /* Make room for the additional DTLS fields */ - if( MBEDTLS_SSL_OUT_CONTENT_LEN - ssl->out_msglen < 8 ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "DTLS handshake message too large: " - "size %" MBEDTLS_PRINTF_SIZET ", maximum %" MBEDTLS_PRINTF_SIZET, - hs_len, - (size_t) ( MBEDTLS_SSL_OUT_CONTENT_LEN - 12 ) ) ); - return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); - } - - memmove( ssl->out_msg + 12, ssl->out_msg + 4, hs_len ); - ssl->out_msglen += 8; - - /* Write message_seq and update it, except for HelloRequest */ - if( hs_type != MBEDTLS_SSL_HS_HELLO_REQUEST ) - { - ssl->out_msg[4] = ( ssl->handshake->out_msg_seq >> 8 ) & 0xFF; - ssl->out_msg[5] = ( ssl->handshake->out_msg_seq ) & 0xFF; - ++( ssl->handshake->out_msg_seq ); - } - else - { - ssl->out_msg[4] = 0; - ssl->out_msg[5] = 0; - } - - /* Handshake hashes are computed without fragmentation, - * so set frag_offset = 0 and frag_len = hs_len for now */ - memset( ssl->out_msg + 6, 0x00, 3 ); - memcpy( ssl->out_msg + 9, ssl->out_msg + 1, 3 ); - } -#endif /* MBEDTLS_SSL_PROTO_DTLS */ - - /* Update running hashes of handshake messages seen */ - if( hs_type != MBEDTLS_SSL_HS_HELLO_REQUEST ) - ssl->handshake->update_checksum( ssl, ssl->out_msg, ssl->out_msglen ); - } - - /* Either send now, or just save to be sent (and resent) later */ -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && - ! ( ssl->out_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE && - hs_type == MBEDTLS_SSL_HS_HELLO_REQUEST ) ) - { - if( ( ret = ssl_flight_append( ssl ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "ssl_flight_append", ret ); - return( ret ); - } - } - else -#endif - { - if( ( ret = mbedtls_ssl_write_record( ssl, SSL_FORCE_FLUSH ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "ssl_write_record", ret ); - return( ret ); - } - } - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write handshake message" ) ); - - return( 0 ); -} - -/* - * Record layer functions - */ - -/* - * Write current record. - * - * Uses: - * - ssl->out_msgtype: type of the message (AppData, Handshake, Alert, CCS) - * - ssl->out_msglen: length of the record content (excl headers) - * - ssl->out_msg: record content - */ -int mbedtls_ssl_write_record( mbedtls_ssl_context *ssl, uint8_t force_flush ) -{ - int ret, done = 0; - size_t len = ssl->out_msglen; - uint8_t flush = force_flush; - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write record" ) ); - -#if defined(MBEDTLS_ZLIB_SUPPORT) - if( ssl->transform_out != NULL && - ssl->session_out->compression == MBEDTLS_SSL_COMPRESS_DEFLATE ) - { - if( ( ret = ssl_compress_buf( ssl ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "ssl_compress_buf", ret ); - return( ret ); - } - - len = ssl->out_msglen; - } -#endif /*MBEDTLS_ZLIB_SUPPORT */ - -#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL) - if( mbedtls_ssl_hw_record_write != NULL ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "going for mbedtls_ssl_hw_record_write()" ) ); - - ret = mbedtls_ssl_hw_record_write( ssl ); - if( ret != 0 && ret != MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_write", ret ); - return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED ); - } - - if( ret == 0 ) - done = 1; - } -#endif /* MBEDTLS_SSL_HW_RECORD_ACCEL */ - if( !done ) - { - unsigned i; - size_t protected_record_size; -#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH) - size_t out_buf_len = ssl->out_buf_len; -#else - size_t out_buf_len = MBEDTLS_SSL_OUT_BUFFER_LEN; -#endif - /* Skip writing the record content type to after the encryption, - * as it may change when using the CID extension. */ - - mbedtls_ssl_write_version( ssl->major_ver, ssl->minor_ver, - ssl->conf->transport, ssl->out_hdr + 1 ); - - memcpy( ssl->out_ctr, ssl->cur_out_ctr, 8 ); - ssl->out_len[0] = (unsigned char)( len >> 8 ); - ssl->out_len[1] = (unsigned char)( len ); - - if( ssl->transform_out != NULL ) - { - mbedtls_record rec; - - rec.buf = ssl->out_iv; - rec.buf_len = out_buf_len - ( ssl->out_iv - ssl->out_buf ); - rec.data_len = ssl->out_msglen; - rec.data_offset = ssl->out_msg - rec.buf; - - memcpy( &rec.ctr[0], ssl->out_ctr, 8 ); - mbedtls_ssl_write_version( ssl->major_ver, ssl->minor_ver, - ssl->conf->transport, rec.ver ); - rec.type = ssl->out_msgtype; - -#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) - /* The CID is set by mbedtls_ssl_encrypt_buf(). */ - rec.cid_len = 0; -#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ - - if( ( ret = mbedtls_ssl_encrypt_buf( ssl, ssl->transform_out, &rec, - ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "ssl_encrypt_buf", ret ); - return( ret ); - } - - if( rec.data_offset != 0 ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - - /* Update the record content type and CID. */ - ssl->out_msgtype = rec.type; -#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID ) - memcpy( ssl->out_cid, rec.cid, rec.cid_len ); -#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ - ssl->out_msglen = len = rec.data_len; - ssl->out_len[0] = (unsigned char)( rec.data_len >> 8 ); - ssl->out_len[1] = (unsigned char)( rec.data_len ); - } - - protected_record_size = len + mbedtls_ssl_out_hdr_len( ssl ); - -#if defined(MBEDTLS_SSL_PROTO_DTLS) - /* In case of DTLS, double-check that we don't exceed - * the remaining space in the datagram. */ - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { - ret = ssl_get_remaining_space_in_datagram( ssl ); - if( ret < 0 ) - return( ret ); - - if( protected_record_size > (size_t) ret ) - { - /* Should never happen */ - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - } -#endif /* MBEDTLS_SSL_PROTO_DTLS */ - - /* Now write the potentially updated record content type. */ - ssl->out_hdr[0] = (unsigned char) ssl->out_msgtype; - - MBEDTLS_SSL_DEBUG_MSG( 3, ( "output record: msgtype = %u, " - "version = [%u:%u], msglen = %" MBEDTLS_PRINTF_SIZET, - ssl->out_hdr[0], ssl->out_hdr[1], - ssl->out_hdr[2], len ) ); - - MBEDTLS_SSL_DEBUG_BUF( 4, "output record sent to network", - ssl->out_hdr, protected_record_size ); - - ssl->out_left += protected_record_size; - ssl->out_hdr += protected_record_size; - mbedtls_ssl_update_out_pointers( ssl, ssl->transform_out ); - - for( i = 8; i > mbedtls_ssl_ep_len( ssl ); i-- ) - if( ++ssl->cur_out_ctr[i - 1] != 0 ) - break; - - /* The loop goes to its end iff the counter is wrapping */ - if( i == mbedtls_ssl_ep_len( ssl ) ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "outgoing message counter would wrap" ) ); - return( MBEDTLS_ERR_SSL_COUNTER_WRAPPING ); - } - } - -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && - flush == SSL_DONT_FORCE_FLUSH ) - { - size_t remaining; - ret = ssl_get_remaining_payload_in_datagram( ssl ); - if( ret < 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "ssl_get_remaining_payload_in_datagram", - ret ); - return( ret ); - } - - remaining = (size_t) ret; - if( remaining == 0 ) - { - flush = SSL_FORCE_FLUSH; - } - else - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "Still %u bytes available in current datagram", (unsigned) remaining ) ); - } - } -#endif /* MBEDTLS_SSL_PROTO_DTLS */ - - if( ( flush == SSL_FORCE_FLUSH ) && - ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_flush_output", ret ); - return( ret ); - } - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write record" ) ); - - return( 0 ); -} - -#if defined(MBEDTLS_SSL_PROTO_DTLS) - -static int ssl_hs_is_proper_fragment( mbedtls_ssl_context *ssl ) -{ - if( ssl->in_msglen < ssl->in_hslen || - memcmp( ssl->in_msg + 6, "\0\0\0", 3 ) != 0 || - memcmp( ssl->in_msg + 9, ssl->in_msg + 1, 3 ) != 0 ) - { - return( 1 ); - } - return( 0 ); -} - -static uint32_t ssl_get_hs_frag_len( mbedtls_ssl_context const *ssl ) -{ - return( ( ssl->in_msg[9] << 16 ) | - ( ssl->in_msg[10] << 8 ) | - ssl->in_msg[11] ); -} - -static uint32_t ssl_get_hs_frag_off( mbedtls_ssl_context const *ssl ) -{ - return( ( ssl->in_msg[6] << 16 ) | - ( ssl->in_msg[7] << 8 ) | - ssl->in_msg[8] ); -} - -static int ssl_check_hs_header( mbedtls_ssl_context const *ssl ) -{ - uint32_t msg_len, frag_off, frag_len; - - msg_len = ssl_get_hs_total_len( ssl ); - frag_off = ssl_get_hs_frag_off( ssl ); - frag_len = ssl_get_hs_frag_len( ssl ); - - if( frag_off > msg_len ) - return( -1 ); - - if( frag_len > msg_len - frag_off ) - return( -1 ); - - if( frag_len + 12 > ssl->in_msglen ) - return( -1 ); - - return( 0 ); -} - -/* - * Mark bits in bitmask (used for DTLS HS reassembly) - */ -static void ssl_bitmask_set( unsigned char *mask, size_t offset, size_t len ) -{ - unsigned int start_bits, end_bits; - - start_bits = 8 - ( offset % 8 ); - if( start_bits != 8 ) - { - size_t first_byte_idx = offset / 8; - - /* Special case */ - if( len <= start_bits ) - { - for( ; len != 0; len-- ) - mask[first_byte_idx] |= 1 << ( start_bits - len ); - - /* Avoid potential issues with offset or len becoming invalid */ - return; - } - - offset += start_bits; /* Now offset % 8 == 0 */ - len -= start_bits; - - for( ; start_bits != 0; start_bits-- ) - mask[first_byte_idx] |= 1 << ( start_bits - 1 ); - } - - end_bits = len % 8; - if( end_bits != 0 ) - { - size_t last_byte_idx = ( offset + len ) / 8; - - len -= end_bits; /* Now len % 8 == 0 */ - - for( ; end_bits != 0; end_bits-- ) - mask[last_byte_idx] |= 1 << ( 8 - end_bits ); - } - - memset( mask + offset / 8, 0xFF, len / 8 ); -} - -/* - * Check that bitmask is full - */ -static int ssl_bitmask_check( unsigned char *mask, size_t len ) -{ - size_t i; - - for( i = 0; i < len / 8; i++ ) - if( mask[i] != 0xFF ) - return( -1 ); - - for( i = 0; i < len % 8; i++ ) - if( ( mask[len / 8] & ( 1 << ( 7 - i ) ) ) == 0 ) - return( -1 ); - - return( 0 ); -} - -/* msg_len does not include the handshake header */ -static size_t ssl_get_reassembly_buffer_size( size_t msg_len, - unsigned add_bitmap ) -{ - size_t alloc_len; - - alloc_len = 12; /* Handshake header */ - alloc_len += msg_len; /* Content buffer */ - - if( add_bitmap ) - alloc_len += msg_len / 8 + ( msg_len % 8 != 0 ); /* Bitmap */ - - return( alloc_len ); -} - -#endif /* MBEDTLS_SSL_PROTO_DTLS */ - -static uint32_t ssl_get_hs_total_len( mbedtls_ssl_context const *ssl ) -{ - return( ( ssl->in_msg[1] << 16 ) | - ( ssl->in_msg[2] << 8 ) | - ssl->in_msg[3] ); -} - -int mbedtls_ssl_prepare_handshake_record( mbedtls_ssl_context *ssl ) -{ - if( ssl->in_msglen < mbedtls_ssl_hs_hdr_len( ssl ) ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "handshake message too short: %" MBEDTLS_PRINTF_SIZET, - ssl->in_msglen ) ); - return( MBEDTLS_ERR_SSL_INVALID_RECORD ); - } - - ssl->in_hslen = mbedtls_ssl_hs_hdr_len( ssl ) + ssl_get_hs_total_len( ssl ); - - MBEDTLS_SSL_DEBUG_MSG( 3, ( "handshake message: msglen =" - " %" MBEDTLS_PRINTF_SIZET ", type = %u, hslen = %" MBEDTLS_PRINTF_SIZET, - ssl->in_msglen, ssl->in_msg[0], ssl->in_hslen ) ); - -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - unsigned int recv_msg_seq = ( ssl->in_msg[4] << 8 ) | ssl->in_msg[5]; - - if( ssl_check_hs_header( ssl ) != 0 ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid handshake header" ) ); - return( MBEDTLS_ERR_SSL_INVALID_RECORD ); - } - - if( ssl->handshake != NULL && - ( ( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER && - recv_msg_seq != ssl->handshake->in_msg_seq ) || - ( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER && - ssl->in_msg[0] != MBEDTLS_SSL_HS_CLIENT_HELLO ) ) ) - { - if( recv_msg_seq > ssl->handshake->in_msg_seq ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "received future handshake message of sequence number %u (next %u)", - recv_msg_seq, - ssl->handshake->in_msg_seq ) ); - return( MBEDTLS_ERR_SSL_EARLY_MESSAGE ); - } - - /* Retransmit only on last message from previous flight, to avoid - * too many retransmissions. - * Besides, No sane server ever retransmits HelloVerifyRequest */ - if( recv_msg_seq == ssl->handshake->in_flight_start_seq - 1 && - ssl->in_msg[0] != MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "received message from last flight, " - "message_seq = %u, start_of_flight = %u", - recv_msg_seq, - ssl->handshake->in_flight_start_seq ) ); - - if( ( ret = mbedtls_ssl_resend( ssl ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_resend", ret ); - return( ret ); - } - } - else - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "dropping out-of-sequence message: " - "message_seq = %u, expected = %u", - recv_msg_seq, - ssl->handshake->in_msg_seq ) ); - } - - return( MBEDTLS_ERR_SSL_CONTINUE_PROCESSING ); - } - /* Wait until message completion to increment in_msg_seq */ - - /* Message reassembly is handled alongside buffering of future - * messages; the commonality is that both handshake fragments and - * future messages cannot be forwarded immediately to the - * handshake logic layer. */ - if( ssl_hs_is_proper_fragment( ssl ) == 1 ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "found fragmented DTLS handshake message" ) ); - return( MBEDTLS_ERR_SSL_EARLY_MESSAGE ); - } - } - else -#endif /* MBEDTLS_SSL_PROTO_DTLS */ - /* With TLS we don't handle fragmentation (for now) */ - if( ssl->in_msglen < ssl->in_hslen ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "TLS handshake fragmentation not supported" ) ); - return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE ); - } - - return( 0 ); -} - -void mbedtls_ssl_update_handshake_status( mbedtls_ssl_context *ssl ) -{ - mbedtls_ssl_handshake_params * const hs = ssl->handshake; - - if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER && hs != NULL ) - { - ssl->handshake->update_checksum( ssl, ssl->in_msg, ssl->in_hslen ); - } - - /* Handshake message is complete, increment counter */ -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && - ssl->handshake != NULL ) - { - unsigned offset; - mbedtls_ssl_hs_buffer *hs_buf; - - /* Increment handshake sequence number */ - hs->in_msg_seq++; - - /* - * Clear up handshake buffering and reassembly structure. - */ - - /* Free first entry */ - ssl_buffering_free_slot( ssl, 0 ); - - /* Shift all other entries */ - for( offset = 0, hs_buf = &hs->buffering.hs[0]; - offset + 1 < MBEDTLS_SSL_MAX_BUFFERED_HS; - offset++, hs_buf++ ) - { - *hs_buf = *(hs_buf + 1); - } - - /* Create a fresh last entry */ - memset( hs_buf, 0, sizeof( mbedtls_ssl_hs_buffer ) ); - } -#endif -} - -/* - * DTLS anti-replay: RFC 6347 4.1.2.6 - * - * in_window is a field of bits numbered from 0 (lsb) to 63 (msb). - * Bit n is set iff record number in_window_top - n has been seen. - * - * Usually, in_window_top is the last record number seen and the lsb of - * in_window is set. The only exception is the initial state (record number 0 - * not seen yet). - */ -#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY) -void mbedtls_ssl_dtls_replay_reset( mbedtls_ssl_context *ssl ) -{ - ssl->in_window_top = 0; - ssl->in_window = 0; -} - -static inline uint64_t ssl_load_six_bytes( unsigned char *buf ) -{ - return( ( (uint64_t) buf[0] << 40 ) | - ( (uint64_t) buf[1] << 32 ) | - ( (uint64_t) buf[2] << 24 ) | - ( (uint64_t) buf[3] << 16 ) | - ( (uint64_t) buf[4] << 8 ) | - ( (uint64_t) buf[5] ) ); -} - -static int mbedtls_ssl_dtls_record_replay_check( mbedtls_ssl_context *ssl, uint8_t *record_in_ctr ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - unsigned char *original_in_ctr; - - // save original in_ctr - original_in_ctr = ssl->in_ctr; - - // use counter from record - ssl->in_ctr = record_in_ctr; - - ret = mbedtls_ssl_dtls_replay_check( (mbedtls_ssl_context const *) ssl ); - - // restore the counter - ssl->in_ctr = original_in_ctr; - - return ret; -} - -/* - * Return 0 if sequence number is acceptable, -1 otherwise - */ -int mbedtls_ssl_dtls_replay_check( mbedtls_ssl_context const *ssl ) -{ - uint64_t rec_seqnum = ssl_load_six_bytes( ssl->in_ctr + 2 ); - uint64_t bit; - - if( ssl->conf->anti_replay == MBEDTLS_SSL_ANTI_REPLAY_DISABLED ) - return( 0 ); - - if( rec_seqnum > ssl->in_window_top ) - return( 0 ); - - bit = ssl->in_window_top - rec_seqnum; - - if( bit >= 64 ) - return( -1 ); - - if( ( ssl->in_window & ( (uint64_t) 1 << bit ) ) != 0 ) - return( -1 ); - - return( 0 ); -} - -/* - * Update replay window on new validated record - */ -void mbedtls_ssl_dtls_replay_update( mbedtls_ssl_context *ssl ) -{ - uint64_t rec_seqnum = ssl_load_six_bytes( ssl->in_ctr + 2 ); - - if( ssl->conf->anti_replay == MBEDTLS_SSL_ANTI_REPLAY_DISABLED ) - return; - - if( rec_seqnum > ssl->in_window_top ) - { - /* Update window_top and the contents of the window */ - uint64_t shift = rec_seqnum - ssl->in_window_top; - - if( shift >= 64 ) - ssl->in_window = 1; - else - { - ssl->in_window <<= shift; - ssl->in_window |= 1; - } - - ssl->in_window_top = rec_seqnum; - } - else - { - /* Mark that number as seen in the current window */ - uint64_t bit = ssl->in_window_top - rec_seqnum; - - if( bit < 64 ) /* Always true, but be extra sure */ - ssl->in_window |= (uint64_t) 1 << bit; - } -} -#endif /* MBEDTLS_SSL_DTLS_ANTI_REPLAY */ - -#if defined(MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE) && defined(MBEDTLS_SSL_SRV_C) -/* - * Without any SSL context, check if a datagram looks like a ClientHello with - * a valid cookie, and if it doesn't, generate a HelloVerifyRequest message. - * Both input and output include full DTLS headers. - * - * - if cookie is valid, return 0 - * - if ClientHello looks superficially valid but cookie is not, - * fill obuf and set olen, then - * return MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED - * - otherwise return a specific error code - */ -static int ssl_check_dtls_clihlo_cookie( - mbedtls_ssl_cookie_write_t *f_cookie_write, - mbedtls_ssl_cookie_check_t *f_cookie_check, - void *p_cookie, - const unsigned char *cli_id, size_t cli_id_len, - const unsigned char *in, size_t in_len, - unsigned char *obuf, size_t buf_len, size_t *olen ) -{ - size_t sid_len, cookie_len; - unsigned char *p; - - /* - * Structure of ClientHello with record and handshake headers, - * and expected values. We don't need to check a lot, more checks will be - * done when actually parsing the ClientHello - skipping those checks - * avoids code duplication and does not make cookie forging any easier. - * - * 0-0 ContentType type; copied, must be handshake - * 1-2 ProtocolVersion version; copied - * 3-4 uint16 epoch; copied, must be 0 - * 5-10 uint48 sequence_number; copied - * 11-12 uint16 length; (ignored) - * - * 13-13 HandshakeType msg_type; (ignored) - * 14-16 uint24 length; (ignored) - * 17-18 uint16 message_seq; copied - * 19-21 uint24 fragment_offset; copied, must be 0 - * 22-24 uint24 fragment_length; (ignored) - * - * 25-26 ProtocolVersion client_version; (ignored) - * 27-58 Random random; (ignored) - * 59-xx SessionID session_id; 1 byte len + sid_len content - * 60+ opaque cookie<0..2^8-1>; 1 byte len + content - * ... - * - * Minimum length is 61 bytes. - */ - if( in_len < 61 || - in[0] != MBEDTLS_SSL_MSG_HANDSHAKE || - in[3] != 0 || in[4] != 0 || - in[19] != 0 || in[20] != 0 || in[21] != 0 ) - { - return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); - } - - sid_len = in[59]; - if( sid_len > in_len - 61 ) - return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); - - cookie_len = in[60 + sid_len]; - if( cookie_len > in_len - 60 ) - return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); - - if( f_cookie_check( p_cookie, in + sid_len + 61, cookie_len, - cli_id, cli_id_len ) == 0 ) - { - /* Valid cookie */ - return( 0 ); - } - - /* - * If we get here, we've got an invalid cookie, let's prepare HVR. - * - * 0-0 ContentType type; copied - * 1-2 ProtocolVersion version; copied - * 3-4 uint16 epoch; copied - * 5-10 uint48 sequence_number; copied - * 11-12 uint16 length; olen - 13 - * - * 13-13 HandshakeType msg_type; hello_verify_request - * 14-16 uint24 length; olen - 25 - * 17-18 uint16 message_seq; copied - * 19-21 uint24 fragment_offset; copied - * 22-24 uint24 fragment_length; olen - 25 - * - * 25-26 ProtocolVersion server_version; 0xfe 0xff - * 27-27 opaque cookie<0..2^8-1>; cookie_len = olen - 27, cookie - * - * Minimum length is 28. - */ - if( buf_len < 28 ) - return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL ); - - /* Copy most fields and adapt others */ - memcpy( obuf, in, 25 ); - obuf[13] = MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST; - obuf[25] = 0xfe; - obuf[26] = 0xff; - - /* Generate and write actual cookie */ - p = obuf + 28; - if( f_cookie_write( p_cookie, - &p, obuf + buf_len, cli_id, cli_id_len ) != 0 ) - { - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - - *olen = p - obuf; - - /* Go back and fill length fields */ - obuf[27] = (unsigned char)( *olen - 28 ); - - obuf[14] = obuf[22] = (unsigned char)( ( *olen - 25 ) >> 16 ); - obuf[15] = obuf[23] = (unsigned char)( ( *olen - 25 ) >> 8 ); - obuf[16] = obuf[24] = (unsigned char)( ( *olen - 25 ) ); - - obuf[11] = (unsigned char)( ( *olen - 13 ) >> 8 ); - obuf[12] = (unsigned char)( ( *olen - 13 ) ); - - return( MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED ); -} - -/* - * Handle possible client reconnect with the same UDP quadruplet - * (RFC 6347 Section 4.2.8). - * - * Called by ssl_parse_record_header() in case we receive an epoch 0 record - * that looks like a ClientHello. - * - * - if the input looks like a ClientHello without cookies, - * send back HelloVerifyRequest, then return 0 - * - if the input looks like a ClientHello with a valid cookie, - * reset the session of the current context, and - * return MBEDTLS_ERR_SSL_CLIENT_RECONNECT - * - if anything goes wrong, return a specific error code - * - * This function is called (through ssl_check_client_reconnect()) when an - * unexpected record is found in ssl_get_next_record(), which will discard the - * record if we return 0, and bubble up the return value otherwise (this - * includes the case of MBEDTLS_ERR_SSL_CLIENT_RECONNECT and of unexpected - * errors, and is the right thing to do in both cases). - */ -static int ssl_handle_possible_reconnect( mbedtls_ssl_context *ssl ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - size_t len; - - if( ssl->conf->f_cookie_write == NULL || - ssl->conf->f_cookie_check == NULL ) - { - /* If we can't use cookies to verify reachability of the peer, - * drop the record. */ - MBEDTLS_SSL_DEBUG_MSG( 1, ( "no cookie callbacks, " - "can't check reconnect validity" ) ); - return( 0 ); - } - - ret = ssl_check_dtls_clihlo_cookie( - ssl->conf->f_cookie_write, - ssl->conf->f_cookie_check, - ssl->conf->p_cookie, - ssl->cli_id, ssl->cli_id_len, - ssl->in_buf, ssl->in_left, - ssl->out_buf, MBEDTLS_SSL_OUT_CONTENT_LEN, &len ); - - MBEDTLS_SSL_DEBUG_RET( 2, "ssl_check_dtls_clihlo_cookie", ret ); - - if( ret == MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED ) - { - int send_ret; - MBEDTLS_SSL_DEBUG_MSG( 1, ( "sending HelloVerifyRequest" ) ); - MBEDTLS_SSL_DEBUG_BUF( 4, "output record sent to network", - ssl->out_buf, len ); - /* Don't check write errors as we can't do anything here. - * If the error is permanent we'll catch it later, - * if it's not, then hopefully it'll work next time. */ - send_ret = ssl->f_send( ssl->p_bio, ssl->out_buf, len ); - MBEDTLS_SSL_DEBUG_RET( 2, "ssl->f_send", send_ret ); - (void) send_ret; - - return( 0 ); - } - - if( ret == 0 ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "cookie is valid, resetting context" ) ); - if( ( ret = mbedtls_ssl_session_reset_int( ssl, 1 ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "reset", ret ); - return( ret ); - } - - return( MBEDTLS_ERR_SSL_CLIENT_RECONNECT ); - } - - return( ret ); -} -#endif /* MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE && MBEDTLS_SSL_SRV_C */ - -static int ssl_check_record_type( uint8_t record_type ) -{ - if( record_type != MBEDTLS_SSL_MSG_HANDSHAKE && - record_type != MBEDTLS_SSL_MSG_ALERT && - record_type != MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC && - record_type != MBEDTLS_SSL_MSG_APPLICATION_DATA ) - { - return( MBEDTLS_ERR_SSL_INVALID_RECORD ); - } - - return( 0 ); -} - -/* - * ContentType type; - * ProtocolVersion version; - * uint16 epoch; // DTLS only - * uint48 sequence_number; // DTLS only - * uint16 length; - * - * Return 0 if header looks sane (and, for DTLS, the record is expected) - * MBEDTLS_ERR_SSL_INVALID_RECORD if the header looks bad, - * MBEDTLS_ERR_SSL_UNEXPECTED_RECORD (DTLS only) if sane but unexpected. - * - * With DTLS, mbedtls_ssl_read_record() will: - * 1. proceed with the record if this function returns 0 - * 2. drop only the current record if this function returns UNEXPECTED_RECORD - * 3. return CLIENT_RECONNECT if this function return that value - * 4. drop the whole datagram if this function returns anything else. - * Point 2 is needed when the peer is resending, and we have already received - * the first record from a datagram but are still waiting for the others. - */ -static int ssl_parse_record_header( mbedtls_ssl_context const *ssl, - unsigned char *buf, - size_t len, - mbedtls_record *rec ) -{ - int major_ver, minor_ver; - - size_t const rec_hdr_type_offset = 0; - size_t const rec_hdr_type_len = 1; - - size_t const rec_hdr_version_offset = rec_hdr_type_offset + - rec_hdr_type_len; - size_t const rec_hdr_version_len = 2; - - size_t const rec_hdr_ctr_len = 8; -#if defined(MBEDTLS_SSL_PROTO_DTLS) - uint32_t rec_epoch; - size_t const rec_hdr_ctr_offset = rec_hdr_version_offset + - rec_hdr_version_len; - -#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) - size_t const rec_hdr_cid_offset = rec_hdr_ctr_offset + - rec_hdr_ctr_len; - size_t rec_hdr_cid_len = 0; -#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ -#endif /* MBEDTLS_SSL_PROTO_DTLS */ - - size_t rec_hdr_len_offset; /* To be determined */ - size_t const rec_hdr_len_len = 2; - - /* - * Check minimum lengths for record header. - */ - -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { - rec_hdr_len_offset = rec_hdr_ctr_offset + rec_hdr_ctr_len; - } - else -#endif /* MBEDTLS_SSL_PROTO_DTLS */ - { - rec_hdr_len_offset = rec_hdr_version_offset + rec_hdr_version_len; - } - - if( len < rec_hdr_len_offset + rec_hdr_len_len ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "datagram of length %u too small to hold DTLS record header of length %u", - (unsigned) len, - (unsigned)( rec_hdr_len_len + rec_hdr_len_len ) ) ); - return( MBEDTLS_ERR_SSL_INVALID_RECORD ); - } - - /* - * Parse and validate record content type - */ - - rec->type = buf[ rec_hdr_type_offset ]; - - /* Check record content type */ -#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) - rec->cid_len = 0; - - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && - ssl->conf->cid_len != 0 && - rec->type == MBEDTLS_SSL_MSG_CID ) - { - /* Shift pointers to account for record header including CID - * struct { - * ContentType special_type = tls12_cid; - * ProtocolVersion version; - * uint16 epoch; - * uint48 sequence_number; - * opaque cid[cid_length]; // Additional field compared to - * // default DTLS record format - * uint16 length; - * opaque enc_content[DTLSCiphertext.length]; - * } DTLSCiphertext; - */ - - /* So far, we only support static CID lengths - * fixed in the configuration. */ - rec_hdr_cid_len = ssl->conf->cid_len; - rec_hdr_len_offset += rec_hdr_cid_len; - - if( len < rec_hdr_len_offset + rec_hdr_len_len ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "datagram of length %u too small to hold DTLS record header including CID, length %u", - (unsigned) len, - (unsigned)( rec_hdr_len_offset + rec_hdr_len_len ) ) ); - return( MBEDTLS_ERR_SSL_INVALID_RECORD ); - } - - /* configured CID len is guaranteed at most 255, see - * MBEDTLS_SSL_CID_OUT_LEN_MAX in check_config.h */ - rec->cid_len = (uint8_t) rec_hdr_cid_len; - memcpy( rec->cid, buf + rec_hdr_cid_offset, rec_hdr_cid_len ); - } - else -#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ - { - if( ssl_check_record_type( rec->type ) ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "unknown record type %u", - (unsigned) rec->type ) ); - return( MBEDTLS_ERR_SSL_INVALID_RECORD ); - } - } - - /* - * Parse and validate record version - */ - - rec->ver[0] = buf[ rec_hdr_version_offset + 0 ]; - rec->ver[1] = buf[ rec_hdr_version_offset + 1 ]; - mbedtls_ssl_read_version( &major_ver, &minor_ver, - ssl->conf->transport, - &rec->ver[0] ); - - if( major_ver != ssl->major_ver ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "major version mismatch" ) ); - return( MBEDTLS_ERR_SSL_INVALID_RECORD ); - } - - if( minor_ver > ssl->conf->max_minor_ver ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "minor version mismatch" ) ); - return( MBEDTLS_ERR_SSL_INVALID_RECORD ); - } - - /* - * Parse/Copy record sequence number. - */ - -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { - /* Copy explicit record sequence number from input buffer. */ - memcpy( &rec->ctr[0], buf + rec_hdr_ctr_offset, - rec_hdr_ctr_len ); - } - else -#endif /* MBEDTLS_SSL_PROTO_DTLS */ - { - /* Copy implicit record sequence number from SSL context structure. */ - memcpy( &rec->ctr[0], ssl->in_ctr, rec_hdr_ctr_len ); - } - - /* - * Parse record length. - */ - - rec->data_offset = rec_hdr_len_offset + rec_hdr_len_len; - rec->data_len = ( (size_t) buf[ rec_hdr_len_offset + 0 ] << 8 ) | - ( (size_t) buf[ rec_hdr_len_offset + 1 ] << 0 ); - MBEDTLS_SSL_DEBUG_BUF( 4, "input record header", buf, rec->data_offset ); - - MBEDTLS_SSL_DEBUG_MSG( 3, ( "input record: msgtype = %u, " - "version = [%d:%d], msglen = %" MBEDTLS_PRINTF_SIZET, - rec->type, - major_ver, minor_ver, rec->data_len ) ); - - rec->buf = buf; - rec->buf_len = rec->data_offset + rec->data_len; - - if( rec->data_len == 0 ) - return( MBEDTLS_ERR_SSL_INVALID_RECORD ); - - /* - * DTLS-related tests. - * Check epoch before checking length constraint because - * the latter varies with the epoch. E.g., if a ChangeCipherSpec - * message gets duplicated before the corresponding Finished message, - * the second ChangeCipherSpec should be discarded because it belongs - * to an old epoch, but not because its length is shorter than - * the minimum record length for packets using the new record transform. - * Note that these two kinds of failures are handled differently, - * as an unexpected record is silently skipped but an invalid - * record leads to the entire datagram being dropped. - */ -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { - rec_epoch = ( rec->ctr[0] << 8 ) | rec->ctr[1]; - - /* Check that the datagram is large enough to contain a record - * of the advertised length. */ - if( len < rec->data_offset + rec->data_len ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "Datagram of length %u too small to contain record of advertised length %u.", - (unsigned) len, - (unsigned)( rec->data_offset + rec->data_len ) ) ); - return( MBEDTLS_ERR_SSL_INVALID_RECORD ); - } - - /* Records from other, non-matching epochs are silently discarded. - * (The case of same-port Client reconnects must be considered in - * the caller). */ - if( rec_epoch != ssl->in_epoch ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "record from another epoch: " - "expected %u, received %lu", - ssl->in_epoch, (unsigned long) rec_epoch ) ); - - /* Records from the next epoch are considered for buffering - * (concretely: early Finished messages). */ - if( rec_epoch == (unsigned) ssl->in_epoch + 1 ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "Consider record for buffering" ) ); - return( MBEDTLS_ERR_SSL_EARLY_MESSAGE ); - } - - return( MBEDTLS_ERR_SSL_UNEXPECTED_RECORD ); - } -#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY) - /* For records from the correct epoch, check whether their - * sequence number has been seen before. */ - else if( mbedtls_ssl_dtls_record_replay_check( (mbedtls_ssl_context *) ssl, - &rec->ctr[0] ) != 0 ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "replayed record" ) ); - return( MBEDTLS_ERR_SSL_UNEXPECTED_RECORD ); - } -#endif - } -#endif /* MBEDTLS_SSL_PROTO_DTLS */ - - return( 0 ); -} - - -#if defined(MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE) && defined(MBEDTLS_SSL_SRV_C) -static int ssl_check_client_reconnect( mbedtls_ssl_context *ssl ) -{ - unsigned int rec_epoch = ( ssl->in_ctr[0] << 8 ) | ssl->in_ctr[1]; - - /* - * Check for an epoch 0 ClientHello. We can't use in_msg here to - * access the first byte of record content (handshake type), as we - * have an active transform (possibly iv_len != 0), so use the - * fact that the record header len is 13 instead. - */ - if( rec_epoch == 0 && - ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER && - ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER && - ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE && - ssl->in_left > 13 && - ssl->in_buf[13] == MBEDTLS_SSL_HS_CLIENT_HELLO ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "possible client reconnect " - "from the same port" ) ); - return( ssl_handle_possible_reconnect( ssl ) ); - } - - return( 0 ); -} -#endif /* MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE && MBEDTLS_SSL_SRV_C */ - -/* - * If applicable, decrypt record content - */ -static int ssl_prepare_record_content( mbedtls_ssl_context *ssl, - mbedtls_record *rec ) -{ - int ret, done = 0; - - MBEDTLS_SSL_DEBUG_BUF( 4, "input record from network", - rec->buf, rec->buf_len ); - -#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL) - if( mbedtls_ssl_hw_record_read != NULL ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "going for mbedtls_ssl_hw_record_read()" ) ); - - ret = mbedtls_ssl_hw_record_read( ssl ); - if( ret != 0 && ret != MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_read", ret ); - return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED ); - } - - if( ret == 0 ) - done = 1; - } -#endif /* MBEDTLS_SSL_HW_RECORD_ACCEL */ - if( !done && ssl->transform_in != NULL ) - { - unsigned char const old_msg_type = rec->type; - - if( ( ret = mbedtls_ssl_decrypt_buf( ssl, ssl->transform_in, - rec ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "ssl_decrypt_buf", ret ); - -#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) - if( ret == MBEDTLS_ERR_SSL_UNEXPECTED_CID && - ssl->conf->ignore_unexpected_cid - == MBEDTLS_SSL_UNEXPECTED_CID_IGNORE ) - { - MBEDTLS_SSL_DEBUG_MSG( 3, ( "ignoring unexpected CID" ) ); - ret = MBEDTLS_ERR_SSL_CONTINUE_PROCESSING; - } -#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ - - return( ret ); - } - - if( old_msg_type != rec->type ) - { - MBEDTLS_SSL_DEBUG_MSG( 4, ( "record type after decrypt (before %d): %d", - old_msg_type, rec->type ) ); - } - - MBEDTLS_SSL_DEBUG_BUF( 4, "input payload after decrypt", - rec->buf + rec->data_offset, rec->data_len ); - -#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) - /* We have already checked the record content type - * in ssl_parse_record_header(), failing or silently - * dropping the record in the case of an unknown type. - * - * Since with the use of CIDs, the record content type - * might change during decryption, re-check the record - * content type, but treat a failure as fatal this time. */ - if( ssl_check_record_type( rec->type ) ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "unknown record type" ) ); - return( MBEDTLS_ERR_SSL_INVALID_RECORD ); - } -#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ - - if( rec->data_len == 0 ) - { -#if defined(MBEDTLS_SSL_PROTO_TLS1_2) - if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 - && rec->type != MBEDTLS_SSL_MSG_APPLICATION_DATA ) - { - /* TLS v1.2 explicitly disallows zero-length messages which are not application data */ - MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid zero-length message type: %d", ssl->in_msgtype ) ); - return( MBEDTLS_ERR_SSL_INVALID_RECORD ); - } -#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ - - ssl->nb_zero++; - - /* - * Three or more empty messages may be a DoS attack - * (excessive CPU consumption). - */ - if( ssl->nb_zero > 3 ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "received four consecutive empty " - "messages, possible DoS attack" ) ); - /* Treat the records as if they were not properly authenticated, - * thereby failing the connection if we see more than allowed - * by the configured bad MAC threshold. */ - return( MBEDTLS_ERR_SSL_INVALID_MAC ); - } - } - else - ssl->nb_zero = 0; - -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { - ; /* in_ctr read from peer, not maintained internally */ - } - else -#endif - { - unsigned i; - for( i = 8; i > mbedtls_ssl_ep_len( ssl ); i-- ) - if( ++ssl->in_ctr[i - 1] != 0 ) - break; - - /* The loop goes to its end iff the counter is wrapping */ - if( i == mbedtls_ssl_ep_len( ssl ) ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "incoming message counter would wrap" ) ); - return( MBEDTLS_ERR_SSL_COUNTER_WRAPPING ); - } - } - - } - -#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { - mbedtls_ssl_dtls_replay_update( ssl ); - } -#endif - - /* Check actual (decrypted) record content length against - * configured maximum. */ - if( ssl->in_msglen > MBEDTLS_SSL_IN_CONTENT_LEN ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) ); - return( MBEDTLS_ERR_SSL_INVALID_RECORD ); - } - - return( 0 ); -} - -/* - * Read a record. - * - * Silently ignore non-fatal alert (and for DTLS, invalid records as well, - * RFC 6347 4.1.2.7) and continue reading until a valid record is found. - * - */ - -/* Helper functions for mbedtls_ssl_read_record(). */ -static int ssl_consume_current_message( mbedtls_ssl_context *ssl ); -static int ssl_get_next_record( mbedtls_ssl_context *ssl ); -static int ssl_record_is_in_progress( mbedtls_ssl_context *ssl ); - -int mbedtls_ssl_read_record( mbedtls_ssl_context *ssl, - unsigned update_hs_digest ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> read record" ) ); - - if( ssl->keep_current_message == 0 ) - { - do { - - ret = ssl_consume_current_message( ssl ); - if( ret != 0 ) - return( ret ); - - if( ssl_record_is_in_progress( ssl ) == 0 ) - { -#if defined(MBEDTLS_SSL_PROTO_DTLS) - int have_buffered = 0; - - /* We only check for buffered messages if the - * current datagram is fully consumed. */ - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && - ssl_next_record_is_in_datagram( ssl ) == 0 ) - { - if( ssl_load_buffered_message( ssl ) == 0 ) - have_buffered = 1; - } - - if( have_buffered == 0 ) -#endif /* MBEDTLS_SSL_PROTO_DTLS */ - { - ret = ssl_get_next_record( ssl ); - if( ret == MBEDTLS_ERR_SSL_CONTINUE_PROCESSING ) - continue; - - if( ret != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_get_next_record" ), ret ); - return( ret ); - } - } - } - - ret = mbedtls_ssl_handle_message_type( ssl ); - -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ret == MBEDTLS_ERR_SSL_EARLY_MESSAGE ) - { - /* Buffer future message */ - ret = ssl_buffer_message( ssl ); - if( ret != 0 ) - return( ret ); - - ret = MBEDTLS_ERR_SSL_CONTINUE_PROCESSING; - } -#endif /* MBEDTLS_SSL_PROTO_DTLS */ - - } while( MBEDTLS_ERR_SSL_NON_FATAL == ret || - MBEDTLS_ERR_SSL_CONTINUE_PROCESSING == ret ); - - if( 0 != ret ) - { - MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ssl_handle_message_type" ), ret ); - return( ret ); - } - - if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE && - update_hs_digest == 1 ) - { - mbedtls_ssl_update_handshake_status( ssl ); - } - } - else - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "reuse previously read message" ) ); - ssl->keep_current_message = 0; - } - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= read record" ) ); - - return( 0 ); -} - -#if defined(MBEDTLS_SSL_PROTO_DTLS) -static int ssl_next_record_is_in_datagram( mbedtls_ssl_context *ssl ) -{ - if( ssl->in_left > ssl->next_record_offset ) - return( 1 ); - - return( 0 ); -} - -static int ssl_load_buffered_message( mbedtls_ssl_context *ssl ) -{ - mbedtls_ssl_handshake_params * const hs = ssl->handshake; - mbedtls_ssl_hs_buffer * hs_buf; - int ret = 0; - - if( hs == NULL ) - return( -1 ); - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> ssl_load_buffered_messsage" ) ); - - if( ssl->state == MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC || - ssl->state == MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC ) - { - /* Check if we have seen a ChangeCipherSpec before. - * If yes, synthesize a CCS record. */ - if( !hs->buffering.seen_ccs ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "CCS not seen in the current flight" ) ); - ret = -1; - goto exit; - } - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "Injecting buffered CCS message" ) ); - ssl->in_msgtype = MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC; - ssl->in_msglen = 1; - ssl->in_msg[0] = 1; - - /* As long as they are equal, the exact value doesn't matter. */ - ssl->in_left = 0; - ssl->next_record_offset = 0; - - hs->buffering.seen_ccs = 0; - goto exit; - } - -#if defined(MBEDTLS_DEBUG_C) - /* Debug only */ - { - unsigned offset; - for( offset = 1; offset < MBEDTLS_SSL_MAX_BUFFERED_HS; offset++ ) - { - hs_buf = &hs->buffering.hs[offset]; - if( hs_buf->is_valid == 1 ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "Future message with sequence number %u %s buffered.", - hs->in_msg_seq + offset, - hs_buf->is_complete ? "fully" : "partially" ) ); - } - } - } -#endif /* MBEDTLS_DEBUG_C */ - - /* Check if we have buffered and/or fully reassembled the - * next handshake message. */ - hs_buf = &hs->buffering.hs[0]; - if( ( hs_buf->is_valid == 1 ) && ( hs_buf->is_complete == 1 ) ) - { - /* Synthesize a record containing the buffered HS message. */ - size_t msg_len = ( hs_buf->data[1] << 16 ) | - ( hs_buf->data[2] << 8 ) | - hs_buf->data[3]; - - /* Double-check that we haven't accidentally buffered - * a message that doesn't fit into the input buffer. */ - if( msg_len + 12 > MBEDTLS_SSL_IN_CONTENT_LEN ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "Next handshake message has been buffered - load" ) ); - MBEDTLS_SSL_DEBUG_BUF( 3, "Buffered handshake message (incl. header)", - hs_buf->data, msg_len + 12 ); - - ssl->in_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE; - ssl->in_hslen = msg_len + 12; - ssl->in_msglen = msg_len + 12; - memcpy( ssl->in_msg, hs_buf->data, ssl->in_hslen ); - - ret = 0; - goto exit; - } - else - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "Next handshake message %u not or only partially bufffered", - hs->in_msg_seq ) ); - } - - ret = -1; - -exit: - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= ssl_load_buffered_message" ) ); - return( ret ); -} - -static int ssl_buffer_make_space( mbedtls_ssl_context *ssl, - size_t desired ) -{ - int offset; - mbedtls_ssl_handshake_params * const hs = ssl->handshake; - MBEDTLS_SSL_DEBUG_MSG( 2, ( "Attempt to free buffered messages to have %u bytes available", - (unsigned) desired ) ); - - /* Get rid of future records epoch first, if such exist. */ - ssl_free_buffered_record( ssl ); - - /* Check if we have enough space available now. */ - if( desired <= ( MBEDTLS_SSL_DTLS_MAX_BUFFERING - - hs->buffering.total_bytes_buffered ) ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "Enough space available after freeing future epoch record" ) ); - return( 0 ); - } - - /* We don't have enough space to buffer the next expected handshake - * message. Remove buffers used for future messages to gain space, - * starting with the most distant one. */ - for( offset = MBEDTLS_SSL_MAX_BUFFERED_HS - 1; - offset >= 0; offset-- ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "Free buffering slot %d to make space for reassembly of next handshake message", - offset ) ); - - ssl_buffering_free_slot( ssl, (uint8_t) offset ); - - /* Check if we have enough space available now. */ - if( desired <= ( MBEDTLS_SSL_DTLS_MAX_BUFFERING - - hs->buffering.total_bytes_buffered ) ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "Enough space available after freeing buffered HS messages" ) ); - return( 0 ); - } - } - - return( -1 ); -} - -static int ssl_buffer_message( mbedtls_ssl_context *ssl ) -{ - int ret = 0; - mbedtls_ssl_handshake_params * const hs = ssl->handshake; - - if( hs == NULL ) - return( 0 ); - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> ssl_buffer_message" ) ); - - switch( ssl->in_msgtype ) - { - case MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC: - MBEDTLS_SSL_DEBUG_MSG( 2, ( "Remember CCS message" ) ); - - hs->buffering.seen_ccs = 1; - break; - - case MBEDTLS_SSL_MSG_HANDSHAKE: - { - unsigned recv_msg_seq_offset; - unsigned recv_msg_seq = ( ssl->in_msg[4] << 8 ) | ssl->in_msg[5]; - mbedtls_ssl_hs_buffer *hs_buf; - size_t msg_len = ssl->in_hslen - 12; - - /* We should never receive an old handshake - * message - double-check nonetheless. */ - if( recv_msg_seq < ssl->handshake->in_msg_seq ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - - recv_msg_seq_offset = recv_msg_seq - ssl->handshake->in_msg_seq; - if( recv_msg_seq_offset >= MBEDTLS_SSL_MAX_BUFFERED_HS ) - { - /* Silently ignore -- message too far in the future */ - MBEDTLS_SSL_DEBUG_MSG( 2, - ( "Ignore future HS message with sequence number %u, " - "buffering window %u - %u", - recv_msg_seq, ssl->handshake->in_msg_seq, - ssl->handshake->in_msg_seq + MBEDTLS_SSL_MAX_BUFFERED_HS - 1 ) ); - - goto exit; - } - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffering HS message with sequence number %u, offset %u ", - recv_msg_seq, recv_msg_seq_offset ) ); - - hs_buf = &hs->buffering.hs[ recv_msg_seq_offset ]; - - /* Check if the buffering for this seq nr has already commenced. */ - if( !hs_buf->is_valid ) - { - size_t reassembly_buf_sz; - - hs_buf->is_fragmented = - ( ssl_hs_is_proper_fragment( ssl ) == 1 ); - - /* We copy the message back into the input buffer - * after reassembly, so check that it's not too large. - * This is an implementation-specific limitation - * and not one from the standard, hence it is not - * checked in ssl_check_hs_header(). */ - if( msg_len + 12 > MBEDTLS_SSL_IN_CONTENT_LEN ) - { - /* Ignore message */ - goto exit; - } - - /* Check if we have enough space to buffer the message. */ - if( hs->buffering.total_bytes_buffered > - MBEDTLS_SSL_DTLS_MAX_BUFFERING ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - - reassembly_buf_sz = ssl_get_reassembly_buffer_size( msg_len, - hs_buf->is_fragmented ); - - if( reassembly_buf_sz > ( MBEDTLS_SSL_DTLS_MAX_BUFFERING - - hs->buffering.total_bytes_buffered ) ) - { - if( recv_msg_seq_offset > 0 ) - { - /* If we can't buffer a future message because - * of space limitations -- ignore. */ - MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffering of future message of size %" MBEDTLS_PRINTF_SIZET - " would exceed the compile-time limit %" MBEDTLS_PRINTF_SIZET - " (already %" MBEDTLS_PRINTF_SIZET - " bytes buffered) -- ignore\n", - msg_len, (size_t) MBEDTLS_SSL_DTLS_MAX_BUFFERING, - hs->buffering.total_bytes_buffered ) ); - goto exit; - } - else - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffering of future message of size %" MBEDTLS_PRINTF_SIZET - " would exceed the compile-time limit %" MBEDTLS_PRINTF_SIZET - " (already %" MBEDTLS_PRINTF_SIZET - " bytes buffered) -- attempt to make space by freeing buffered future messages\n", - msg_len, (size_t) MBEDTLS_SSL_DTLS_MAX_BUFFERING, - hs->buffering.total_bytes_buffered ) ); - } - - if( ssl_buffer_make_space( ssl, reassembly_buf_sz ) != 0 ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "Reassembly of next message of size %" MBEDTLS_PRINTF_SIZET - " (%" MBEDTLS_PRINTF_SIZET " with bitmap) would exceed" - " the compile-time limit %" MBEDTLS_PRINTF_SIZET - " (already %" MBEDTLS_PRINTF_SIZET - " bytes buffered) -- fail\n", - msg_len, - reassembly_buf_sz, - (size_t) MBEDTLS_SSL_DTLS_MAX_BUFFERING, - hs->buffering.total_bytes_buffered ) ); - ret = MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL; - goto exit; - } - } - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "initialize reassembly, total length = %" MBEDTLS_PRINTF_SIZET, - msg_len ) ); - - hs_buf->data = mbedtls_calloc( 1, reassembly_buf_sz ); - if( hs_buf->data == NULL ) - { - ret = MBEDTLS_ERR_SSL_ALLOC_FAILED; - goto exit; - } - hs_buf->data_len = reassembly_buf_sz; - - /* Prepare final header: copy msg_type, length and message_seq, - * then add standardised fragment_offset and fragment_length */ - memcpy( hs_buf->data, ssl->in_msg, 6 ); - memset( hs_buf->data + 6, 0, 3 ); - memcpy( hs_buf->data + 9, hs_buf->data + 1, 3 ); - - hs_buf->is_valid = 1; - - hs->buffering.total_bytes_buffered += reassembly_buf_sz; - } - else - { - /* Make sure msg_type and length are consistent */ - if( memcmp( hs_buf->data, ssl->in_msg, 4 ) != 0 ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "Fragment header mismatch - ignore" ) ); - /* Ignore */ - goto exit; - } - } - - if( !hs_buf->is_complete ) - { - size_t frag_len, frag_off; - unsigned char * const msg = hs_buf->data + 12; - - /* - * Check and copy current fragment - */ - - /* Validation of header fields already done in - * mbedtls_ssl_prepare_handshake_record(). */ - frag_off = ssl_get_hs_frag_off( ssl ); - frag_len = ssl_get_hs_frag_len( ssl ); - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "adding fragment, offset = %" MBEDTLS_PRINTF_SIZET - ", length = %" MBEDTLS_PRINTF_SIZET, - frag_off, frag_len ) ); - memcpy( msg + frag_off, ssl->in_msg + 12, frag_len ); - - if( hs_buf->is_fragmented ) - { - unsigned char * const bitmask = msg + msg_len; - ssl_bitmask_set( bitmask, frag_off, frag_len ); - hs_buf->is_complete = ( ssl_bitmask_check( bitmask, - msg_len ) == 0 ); - } - else - { - hs_buf->is_complete = 1; - } - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "message %scomplete", - hs_buf->is_complete ? "" : "not yet " ) ); - } - - break; - } - - default: - /* We don't buffer other types of messages. */ - break; - } - -exit: - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= ssl_buffer_message" ) ); - return( ret ); -} -#endif /* MBEDTLS_SSL_PROTO_DTLS */ - -static int ssl_consume_current_message( mbedtls_ssl_context *ssl ) -{ - /* - * Consume last content-layer message and potentially - * update in_msglen which keeps track of the contents' - * consumption state. - * - * (1) Handshake messages: - * Remove last handshake message, move content - * and adapt in_msglen. - * - * (2) Alert messages: - * Consume whole record content, in_msglen = 0. - * - * (3) Change cipher spec: - * Consume whole record content, in_msglen = 0. - * - * (4) Application data: - * Don't do anything - the record layer provides - * the application data as a stream transport - * and consumes through mbedtls_ssl_read only. - * - */ - - /* Case (1): Handshake messages */ - if( ssl->in_hslen != 0 ) - { - /* Hard assertion to be sure that no application data - * is in flight, as corrupting ssl->in_msglen during - * ssl->in_offt != NULL is fatal. */ - if( ssl->in_offt != NULL ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - - /* - * Get next Handshake message in the current record - */ - - /* Notes: - * (1) in_hslen is not necessarily the size of the - * current handshake content: If DTLS handshake - * fragmentation is used, that's the fragment - * size instead. Using the total handshake message - * size here is faulty and should be changed at - * some point. - * (2) While it doesn't seem to cause problems, one - * has to be very careful not to assume that in_hslen - * is always <= in_msglen in a sensible communication. - * Again, it's wrong for DTLS handshake fragmentation. - * The following check is therefore mandatory, and - * should not be treated as a silently corrected assertion. - * Additionally, ssl->in_hslen might be arbitrarily out of - * bounds after handling a DTLS message with an unexpected - * sequence number, see mbedtls_ssl_prepare_handshake_record. - */ - if( ssl->in_hslen < ssl->in_msglen ) - { - ssl->in_msglen -= ssl->in_hslen; - memmove( ssl->in_msg, ssl->in_msg + ssl->in_hslen, - ssl->in_msglen ); - - MBEDTLS_SSL_DEBUG_BUF( 4, "remaining content in record", - ssl->in_msg, ssl->in_msglen ); - } - else - { - ssl->in_msglen = 0; - } - - ssl->in_hslen = 0; - } - /* Case (4): Application data */ - else if( ssl->in_offt != NULL ) - { - return( 0 ); - } - /* Everything else (CCS & Alerts) */ - else - { - ssl->in_msglen = 0; - } - - return( 0 ); -} - -static int ssl_record_is_in_progress( mbedtls_ssl_context *ssl ) -{ - if( ssl->in_msglen > 0 ) - return( 1 ); - - return( 0 ); -} - -#if defined(MBEDTLS_SSL_PROTO_DTLS) - -static void ssl_free_buffered_record( mbedtls_ssl_context *ssl ) -{ - mbedtls_ssl_handshake_params * const hs = ssl->handshake; - if( hs == NULL ) - return; - - if( hs->buffering.future_record.data != NULL ) - { - hs->buffering.total_bytes_buffered -= - hs->buffering.future_record.len; - - mbedtls_free( hs->buffering.future_record.data ); - hs->buffering.future_record.data = NULL; - } -} - -static int ssl_load_buffered_record( mbedtls_ssl_context *ssl ) -{ - mbedtls_ssl_handshake_params * const hs = ssl->handshake; - unsigned char * rec; - size_t rec_len; - unsigned rec_epoch; -#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH) - size_t in_buf_len = ssl->in_buf_len; -#else - size_t in_buf_len = MBEDTLS_SSL_IN_BUFFER_LEN; -#endif - if( ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - return( 0 ); - - if( hs == NULL ) - return( 0 ); - - rec = hs->buffering.future_record.data; - rec_len = hs->buffering.future_record.len; - rec_epoch = hs->buffering.future_record.epoch; - - if( rec == NULL ) - return( 0 ); - - /* Only consider loading future records if the - * input buffer is empty. */ - if( ssl_next_record_is_in_datagram( ssl ) == 1 ) - return( 0 ); - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> ssl_load_buffered_record" ) ); - - if( rec_epoch != ssl->in_epoch ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffered record not from current epoch." ) ); - goto exit; - } - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "Found buffered record from current epoch - load" ) ); - - /* Double-check that the record is not too large */ - if( rec_len > in_buf_len - (size_t)( ssl->in_hdr - ssl->in_buf ) ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - - memcpy( ssl->in_hdr, rec, rec_len ); - ssl->in_left = rec_len; - ssl->next_record_offset = 0; - - ssl_free_buffered_record( ssl ); - -exit: - MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= ssl_load_buffered_record" ) ); - return( 0 ); -} - -static int ssl_buffer_future_record( mbedtls_ssl_context *ssl, - mbedtls_record const *rec ) -{ - mbedtls_ssl_handshake_params * const hs = ssl->handshake; - - /* Don't buffer future records outside handshakes. */ - if( hs == NULL ) - return( 0 ); - - /* Only buffer handshake records (we are only interested - * in Finished messages). */ - if( rec->type != MBEDTLS_SSL_MSG_HANDSHAKE ) - return( 0 ); - - /* Don't buffer more than one future epoch record. */ - if( hs->buffering.future_record.data != NULL ) - return( 0 ); - - /* Don't buffer record if there's not enough buffering space remaining. */ - if( rec->buf_len > ( MBEDTLS_SSL_DTLS_MAX_BUFFERING - - hs->buffering.total_bytes_buffered ) ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffering of future epoch record of size %" MBEDTLS_PRINTF_SIZET - " would exceed the compile-time limit %" MBEDTLS_PRINTF_SIZET - " (already %" MBEDTLS_PRINTF_SIZET - " bytes buffered) -- ignore\n", - rec->buf_len, (size_t) MBEDTLS_SSL_DTLS_MAX_BUFFERING, - hs->buffering.total_bytes_buffered ) ); - return( 0 ); - } - - /* Buffer record */ - MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffer record from epoch %u", - ssl->in_epoch + 1U ) ); - MBEDTLS_SSL_DEBUG_BUF( 3, "Buffered record", rec->buf, rec->buf_len ); - - /* ssl_parse_record_header() only considers records - * of the next epoch as candidates for buffering. */ - hs->buffering.future_record.epoch = ssl->in_epoch + 1; - hs->buffering.future_record.len = rec->buf_len; - - hs->buffering.future_record.data = - mbedtls_calloc( 1, hs->buffering.future_record.len ); - if( hs->buffering.future_record.data == NULL ) - { - /* If we run out of RAM trying to buffer a - * record from the next epoch, just ignore. */ - return( 0 ); - } - - memcpy( hs->buffering.future_record.data, rec->buf, rec->buf_len ); - - hs->buffering.total_bytes_buffered += rec->buf_len; - return( 0 ); -} - -#endif /* MBEDTLS_SSL_PROTO_DTLS */ - -static int ssl_get_next_record( mbedtls_ssl_context *ssl ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - mbedtls_record rec; - -#if defined(MBEDTLS_SSL_PROTO_DTLS) - /* We might have buffered a future record; if so, - * and if the epoch matches now, load it. - * On success, this call will set ssl->in_left to - * the length of the buffered record, so that - * the calls to ssl_fetch_input() below will - * essentially be no-ops. */ - ret = ssl_load_buffered_record( ssl ); - if( ret != 0 ) - return( ret ); -#endif /* MBEDTLS_SSL_PROTO_DTLS */ - - /* Ensure that we have enough space available for the default form - * of TLS / DTLS record headers (5 Bytes for TLS, 13 Bytes for DTLS, - * with no space for CIDs counted in). */ - ret = mbedtls_ssl_fetch_input( ssl, mbedtls_ssl_in_hdr_len( ssl ) ); - if( ret != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_fetch_input", ret ); - return( ret ); - } - - ret = ssl_parse_record_header( ssl, ssl->in_hdr, ssl->in_left, &rec ); - if( ret != 0 ) - { -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { - if( ret == MBEDTLS_ERR_SSL_EARLY_MESSAGE ) - { - ret = ssl_buffer_future_record( ssl, &rec ); - if( ret != 0 ) - return( ret ); - - /* Fall through to handling of unexpected records */ - ret = MBEDTLS_ERR_SSL_UNEXPECTED_RECORD; - } - - if( ret == MBEDTLS_ERR_SSL_UNEXPECTED_RECORD ) - { -#if defined(MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE) && defined(MBEDTLS_SSL_SRV_C) - /* Reset in pointers to default state for TLS/DTLS records, - * assuming no CID and no offset between record content and - * record plaintext. */ - mbedtls_ssl_update_in_pointers( ssl ); - - /* Setup internal message pointers from record structure. */ - ssl->in_msgtype = rec.type; -#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) - ssl->in_len = ssl->in_cid + rec.cid_len; -#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ - ssl->in_iv = ssl->in_msg = ssl->in_len + 2; - ssl->in_msglen = rec.data_len; - - ret = ssl_check_client_reconnect( ssl ); - MBEDTLS_SSL_DEBUG_RET( 2, "ssl_check_client_reconnect", ret ); - if( ret != 0 ) - return( ret ); -#endif - - /* Skip unexpected record (but not whole datagram) */ - ssl->next_record_offset = rec.buf_len; - - MBEDTLS_SSL_DEBUG_MSG( 1, ( "discarding unexpected record " - "(header)" ) ); - } - else - { - /* Skip invalid record and the rest of the datagram */ - ssl->next_record_offset = 0; - ssl->in_left = 0; - - MBEDTLS_SSL_DEBUG_MSG( 1, ( "discarding invalid record " - "(header)" ) ); - } - - /* Get next record */ - return( MBEDTLS_ERR_SSL_CONTINUE_PROCESSING ); - } - else -#endif - { - return( ret ); - } - } - -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { - /* Remember offset of next record within datagram. */ - ssl->next_record_offset = rec.buf_len; - if( ssl->next_record_offset < ssl->in_left ) - { - MBEDTLS_SSL_DEBUG_MSG( 3, ( "more than one record within datagram" ) ); - } - } - else -#endif - { - /* - * Fetch record contents from underlying transport. - */ - ret = mbedtls_ssl_fetch_input( ssl, rec.buf_len ); - if( ret != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_fetch_input", ret ); - return( ret ); - } - - ssl->in_left = 0; - } - - /* - * Decrypt record contents. - */ - - if( ( ret = ssl_prepare_record_content( ssl, &rec ) ) != 0 ) - { -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { - /* Silently discard invalid records */ - if( ret == MBEDTLS_ERR_SSL_INVALID_MAC ) - { - /* Except when waiting for Finished as a bad mac here - * probably means something went wrong in the handshake - * (eg wrong psk used, mitm downgrade attempt, etc.) */ - if( ssl->state == MBEDTLS_SSL_CLIENT_FINISHED || - ssl->state == MBEDTLS_SSL_SERVER_FINISHED ) - { -#if defined(MBEDTLS_SSL_ALL_ALERT_MESSAGES) - if( ret == MBEDTLS_ERR_SSL_INVALID_MAC ) - { - mbedtls_ssl_send_alert_message( ssl, - MBEDTLS_SSL_ALERT_LEVEL_FATAL, - MBEDTLS_SSL_ALERT_MSG_BAD_RECORD_MAC ); - } -#endif - return( ret ); - } - -#if defined(MBEDTLS_SSL_DTLS_BADMAC_LIMIT) - if( ssl->conf->badmac_limit != 0 && - ++ssl->badmac_seen >= ssl->conf->badmac_limit ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "too many records with bad MAC" ) ); - return( MBEDTLS_ERR_SSL_INVALID_MAC ); - } -#endif - - /* As above, invalid records cause - * dismissal of the whole datagram. */ - - ssl->next_record_offset = 0; - ssl->in_left = 0; - - MBEDTLS_SSL_DEBUG_MSG( 1, ( "discarding invalid record (mac)" ) ); - return( MBEDTLS_ERR_SSL_CONTINUE_PROCESSING ); - } - - return( ret ); - } - else -#endif - { - /* Error out (and send alert) on invalid records */ -#if defined(MBEDTLS_SSL_ALL_ALERT_MESSAGES) - if( ret == MBEDTLS_ERR_SSL_INVALID_MAC ) - { - mbedtls_ssl_send_alert_message( ssl, - MBEDTLS_SSL_ALERT_LEVEL_FATAL, - MBEDTLS_SSL_ALERT_MSG_BAD_RECORD_MAC ); - } -#endif - return( ret ); - } - } - - - /* Reset in pointers to default state for TLS/DTLS records, - * assuming no CID and no offset between record content and - * record plaintext. */ - mbedtls_ssl_update_in_pointers( ssl ); -#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) - ssl->in_len = ssl->in_cid + rec.cid_len; -#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ - ssl->in_iv = ssl->in_len + 2; - - /* The record content type may change during decryption, - * so re-read it. */ - ssl->in_msgtype = rec.type; - /* Also update the input buffer, because unfortunately - * the server-side ssl_parse_client_hello() reparses the - * record header when receiving a ClientHello initiating - * a renegotiation. */ - ssl->in_hdr[0] = rec.type; - ssl->in_msg = rec.buf + rec.data_offset; - ssl->in_msglen = rec.data_len; - ssl->in_len[0] = (unsigned char)( rec.data_len >> 8 ); - ssl->in_len[1] = (unsigned char)( rec.data_len ); - -#if defined(MBEDTLS_ZLIB_SUPPORT) - if( ssl->transform_in != NULL && - ssl->session_in->compression == MBEDTLS_SSL_COMPRESS_DEFLATE ) - { - if( ( ret = ssl_decompress_buf( ssl ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "ssl_decompress_buf", ret ); - return( ret ); - } - - /* Check actual (decompress) record content length against - * configured maximum. */ - if( ssl->in_msglen > MBEDTLS_SSL_IN_CONTENT_LEN ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) ); - return( MBEDTLS_ERR_SSL_INVALID_RECORD ); - } - } -#endif /* MBEDTLS_ZLIB_SUPPORT */ - - return( 0 ); -} - -int mbedtls_ssl_handle_message_type( mbedtls_ssl_context *ssl ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - - /* - * Handle particular types of records - */ - if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE ) - { - if( ( ret = mbedtls_ssl_prepare_handshake_record( ssl ) ) != 0 ) - { - return( ret ); - } - } - - if( ssl->in_msgtype == MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC ) - { - if( ssl->in_msglen != 1 ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid CCS message, len: %" MBEDTLS_PRINTF_SIZET, - ssl->in_msglen ) ); - return( MBEDTLS_ERR_SSL_INVALID_RECORD ); - } - - if( ssl->in_msg[0] != 1 ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid CCS message, content: %02x", - ssl->in_msg[0] ) ); - return( MBEDTLS_ERR_SSL_INVALID_RECORD ); - } - -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && - ssl->state != MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC && - ssl->state != MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC ) - { - if( ssl->handshake == NULL ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "dropping ChangeCipherSpec outside handshake" ) ); - return( MBEDTLS_ERR_SSL_UNEXPECTED_RECORD ); - } - - MBEDTLS_SSL_DEBUG_MSG( 1, ( "received out-of-order ChangeCipherSpec - remember" ) ); - return( MBEDTLS_ERR_SSL_EARLY_MESSAGE ); - } -#endif - } - - if( ssl->in_msgtype == MBEDTLS_SSL_MSG_ALERT ) - { - if( ssl->in_msglen != 2 ) - { - /* Note: Standard allows for more than one 2 byte alert - to be packed in a single message, but Mbed TLS doesn't - currently support this. */ - MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid alert message, len: %" MBEDTLS_PRINTF_SIZET, - ssl->in_msglen ) ); - return( MBEDTLS_ERR_SSL_INVALID_RECORD ); - } - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "got an alert message, type: [%u:%u]", - ssl->in_msg[0], ssl->in_msg[1] ) ); - - /* - * Ignore non-fatal alerts, except close_notify and no_renegotiation - */ - if( ssl->in_msg[0] == MBEDTLS_SSL_ALERT_LEVEL_FATAL ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "is a fatal alert message (msg %d)", - ssl->in_msg[1] ) ); - return( MBEDTLS_ERR_SSL_FATAL_ALERT_MESSAGE ); - } - - if( ssl->in_msg[0] == MBEDTLS_SSL_ALERT_LEVEL_WARNING && - ssl->in_msg[1] == MBEDTLS_SSL_ALERT_MSG_CLOSE_NOTIFY ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "is a close notify message" ) ); - return( MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY ); - } - -#if defined(MBEDTLS_SSL_RENEGOTIATION_ENABLED) - if( ssl->in_msg[0] == MBEDTLS_SSL_ALERT_LEVEL_WARNING && - ssl->in_msg[1] == MBEDTLS_SSL_ALERT_MSG_NO_RENEGOTIATION ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "is a SSLv3 no renegotiation alert" ) ); - /* Will be handled when trying to parse ServerHello */ - return( 0 ); - } -#endif - -#if defined(MBEDTLS_SSL_PROTO_SSL3) && defined(MBEDTLS_SSL_SRV_C) - if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 && - ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER && - ssl->in_msg[0] == MBEDTLS_SSL_ALERT_LEVEL_WARNING && - ssl->in_msg[1] == MBEDTLS_SSL_ALERT_MSG_NO_CERT ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "is a SSLv3 no_cert" ) ); - /* Will be handled in mbedtls_ssl_parse_certificate() */ - return( 0 ); - } -#endif /* MBEDTLS_SSL_PROTO_SSL3 && MBEDTLS_SSL_SRV_C */ - - /* Silently ignore: fetch new message */ - return MBEDTLS_ERR_SSL_NON_FATAL; - } - -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { - /* Drop unexpected ApplicationData records, - * except at the beginning of renegotiations */ - if( ssl->in_msgtype == MBEDTLS_SSL_MSG_APPLICATION_DATA && - ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER -#if defined(MBEDTLS_SSL_RENEGOTIATION) - && ! ( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS && - ssl->state == MBEDTLS_SSL_SERVER_HELLO ) -#endif - ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "dropping unexpected ApplicationData" ) ); - return( MBEDTLS_ERR_SSL_NON_FATAL ); - } - - if( ssl->handshake != NULL && - ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER ) - { - mbedtls_ssl_handshake_wrapup_free_hs_transform( ssl ); - } - } -#endif /* MBEDTLS_SSL_PROTO_DTLS */ - - return( 0 ); -} - -int mbedtls_ssl_send_fatal_handshake_failure( mbedtls_ssl_context *ssl ) -{ - return( mbedtls_ssl_send_alert_message( ssl, - MBEDTLS_SSL_ALERT_LEVEL_FATAL, - MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE ) ); -} - -int mbedtls_ssl_send_alert_message( mbedtls_ssl_context *ssl, - unsigned char level, - unsigned char message ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - - if( ssl == NULL || ssl->conf == NULL ) - return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> send alert message" ) ); - MBEDTLS_SSL_DEBUG_MSG( 3, ( "send alert level=%u message=%u", level, message )); - - ssl->out_msgtype = MBEDTLS_SSL_MSG_ALERT; - ssl->out_msglen = 2; - ssl->out_msg[0] = level; - ssl->out_msg[1] = message; - - if( ( ret = mbedtls_ssl_write_record( ssl, SSL_FORCE_FLUSH ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret ); - return( ret ); - } - MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= send alert message" ) ); - - return( 0 ); -} - -int mbedtls_ssl_write_change_cipher_spec( mbedtls_ssl_context *ssl ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write change cipher spec" ) ); - - ssl->out_msgtype = MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC; - ssl->out_msglen = 1; - ssl->out_msg[0] = 1; - - ssl->state++; - - if( ( ret = mbedtls_ssl_write_handshake_msg( ssl ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_handshake_msg", ret ); - return( ret ); - } - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write change cipher spec" ) ); - - return( 0 ); -} - -int mbedtls_ssl_parse_change_cipher_spec( mbedtls_ssl_context *ssl ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse change cipher spec" ) ); - - if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret ); - return( ret ); - } - - if( ssl->in_msgtype != MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad change cipher spec message" ) ); - mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, - MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE ); - return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE ); - } - - /* CCS records are only accepted if they have length 1 and content '1', - * so we don't need to check this here. */ - - /* - * Switch to our negotiated transform and session parameters for inbound - * data. - */ - MBEDTLS_SSL_DEBUG_MSG( 3, ( "switching to new transform spec for inbound data" ) ); - ssl->transform_in = ssl->transform_negotiate; - ssl->session_in = ssl->session_negotiate; - -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { -#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY) - mbedtls_ssl_dtls_replay_reset( ssl ); -#endif - - /* Increment epoch */ - if( ++ssl->in_epoch == 0 ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "DTLS epoch would wrap" ) ); - /* This is highly unlikely to happen for legitimate reasons, so - treat it as an attack and don't send an alert. */ - return( MBEDTLS_ERR_SSL_COUNTER_WRAPPING ); - } - } - else -#endif /* MBEDTLS_SSL_PROTO_DTLS */ - memset( ssl->in_ctr, 0, 8 ); - - mbedtls_ssl_update_in_pointers( ssl ); - -#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL) - if( mbedtls_ssl_hw_record_activate != NULL ) - { - if( ( ret = mbedtls_ssl_hw_record_activate( ssl, MBEDTLS_SSL_CHANNEL_INBOUND ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_activate", ret ); - mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, - MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR ); - return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED ); - } - } -#endif - - ssl->state++; - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse change cipher spec" ) ); - - return( 0 ); -} - -/* Once ssl->out_hdr as the address of the beginning of the - * next outgoing record is set, deduce the other pointers. - * - * Note: For TLS, we save the implicit record sequence number - * (entering MAC computation) in the 8 bytes before ssl->out_hdr, - * and the caller has to make sure there's space for this. - */ - -static size_t ssl_transform_get_explicit_iv_len( - mbedtls_ssl_transform const *transform ) -{ - if( transform->minor_ver < MBEDTLS_SSL_MINOR_VERSION_2 ) - return( 0 ); - - return( transform->ivlen - transform->fixed_ivlen ); -} - -void mbedtls_ssl_update_out_pointers( mbedtls_ssl_context *ssl, - mbedtls_ssl_transform *transform ) -{ -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { - ssl->out_ctr = ssl->out_hdr + 3; -#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) - ssl->out_cid = ssl->out_ctr + 8; - ssl->out_len = ssl->out_cid; - if( transform != NULL ) - ssl->out_len += transform->out_cid_len; -#else /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ - ssl->out_len = ssl->out_ctr + 8; -#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ - ssl->out_iv = ssl->out_len + 2; - } - else -#endif - { - ssl->out_ctr = ssl->out_hdr - 8; - ssl->out_len = ssl->out_hdr + 3; -#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) - ssl->out_cid = ssl->out_len; -#endif - ssl->out_iv = ssl->out_hdr + 5; - } - - ssl->out_msg = ssl->out_iv; - /* Adjust out_msg to make space for explicit IV, if used. */ - if( transform != NULL ) - ssl->out_msg += ssl_transform_get_explicit_iv_len( transform ); -} - -/* Once ssl->in_hdr as the address of the beginning of the - * next incoming record is set, deduce the other pointers. - * - * Note: For TLS, we save the implicit record sequence number - * (entering MAC computation) in the 8 bytes before ssl->in_hdr, - * and the caller has to make sure there's space for this. - */ - -void mbedtls_ssl_update_in_pointers( mbedtls_ssl_context *ssl ) -{ - /* This function sets the pointers to match the case - * of unprotected TLS/DTLS records, with both ssl->in_iv - * and ssl->in_msg pointing to the beginning of the record - * content. - * - * When decrypting a protected record, ssl->in_msg - * will be shifted to point to the beginning of the - * record plaintext. - */ - -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { - /* This sets the header pointers to match records - * without CID. When we receive a record containing - * a CID, the fields are shifted accordingly in - * ssl_parse_record_header(). */ - ssl->in_ctr = ssl->in_hdr + 3; -#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) - ssl->in_cid = ssl->in_ctr + 8; - ssl->in_len = ssl->in_cid; /* Default: no CID */ -#else /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ - ssl->in_len = ssl->in_ctr + 8; -#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ - ssl->in_iv = ssl->in_len + 2; - } - else -#endif - { - ssl->in_ctr = ssl->in_hdr - 8; - ssl->in_len = ssl->in_hdr + 3; -#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) - ssl->in_cid = ssl->in_len; -#endif - ssl->in_iv = ssl->in_hdr + 5; - } - - /* This will be adjusted at record decryption time. */ - ssl->in_msg = ssl->in_iv; -} - -/* - * Setup an SSL context - */ - -void mbedtls_ssl_reset_in_out_pointers( mbedtls_ssl_context *ssl ) -{ - /* Set the incoming and outgoing record pointers. */ -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { - ssl->out_hdr = ssl->out_buf; - ssl->in_hdr = ssl->in_buf; - } - else -#endif /* MBEDTLS_SSL_PROTO_DTLS */ - { - ssl->out_hdr = ssl->out_buf + 8; - ssl->in_hdr = ssl->in_buf + 8; - } - - /* Derive other internal pointers. */ - mbedtls_ssl_update_out_pointers( ssl, NULL /* no transform enabled */ ); - mbedtls_ssl_update_in_pointers ( ssl ); -} - -/* - * SSL get accessors - */ -size_t mbedtls_ssl_get_bytes_avail( const mbedtls_ssl_context *ssl ) -{ - return( ssl->in_offt == NULL ? 0 : ssl->in_msglen ); -} - -int mbedtls_ssl_check_pending( const mbedtls_ssl_context *ssl ) -{ - /* - * Case A: We're currently holding back - * a message for further processing. - */ - - if( ssl->keep_current_message == 1 ) - { - MBEDTLS_SSL_DEBUG_MSG( 3, ( "ssl_check_pending: record held back for processing" ) ); - return( 1 ); - } - - /* - * Case B: Further records are pending in the current datagram. - */ - -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && - ssl->in_left > ssl->next_record_offset ) - { - MBEDTLS_SSL_DEBUG_MSG( 3, ( "ssl_check_pending: more records within current datagram" ) ); - return( 1 ); - } -#endif /* MBEDTLS_SSL_PROTO_DTLS */ - - /* - * Case C: A handshake message is being processed. - */ - - if( ssl->in_hslen > 0 && ssl->in_hslen < ssl->in_msglen ) - { - MBEDTLS_SSL_DEBUG_MSG( 3, ( "ssl_check_pending: more handshake messages within current record" ) ); - return( 1 ); - } - - /* - * Case D: An application data message is being processed - */ - if( ssl->in_offt != NULL ) - { - MBEDTLS_SSL_DEBUG_MSG( 3, ( "ssl_check_pending: application data record is being processed" ) ); - return( 1 ); - } - - /* - * In all other cases, the rest of the message can be dropped. - * As in ssl_get_next_record, this needs to be adapted if - * we implement support for multiple alerts in single records. - */ - - MBEDTLS_SSL_DEBUG_MSG( 3, ( "ssl_check_pending: nothing pending" ) ); - return( 0 ); -} - - -int mbedtls_ssl_get_record_expansion( const mbedtls_ssl_context *ssl ) -{ - size_t transform_expansion = 0; - const mbedtls_ssl_transform *transform = ssl->transform_out; - unsigned block_size; - - size_t out_hdr_len = mbedtls_ssl_out_hdr_len( ssl ); - - if( transform == NULL ) - return( (int) out_hdr_len ); - -#if defined(MBEDTLS_ZLIB_SUPPORT) - if( ssl->session_out->compression != MBEDTLS_SSL_COMPRESS_NULL ) - return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE ); -#endif - - switch( mbedtls_cipher_get_cipher_mode( &transform->cipher_ctx_enc ) ) - { - case MBEDTLS_MODE_GCM: - case MBEDTLS_MODE_CCM: - case MBEDTLS_MODE_CHACHAPOLY: - case MBEDTLS_MODE_STREAM: - transform_expansion = transform->minlen; - break; - - case MBEDTLS_MODE_CBC: - - block_size = mbedtls_cipher_get_block_size( - &transform->cipher_ctx_enc ); - - /* Expansion due to the addition of the MAC. */ - transform_expansion += transform->maclen; - - /* Expansion due to the addition of CBC padding; - * Theoretically up to 256 bytes, but we never use - * more than the block size of the underlying cipher. */ - transform_expansion += block_size; - - /* For TLS 1.1 or higher, an explicit IV is added - * after the record header. */ -#if defined(MBEDTLS_SSL_PROTO_TLS1_1) || defined(MBEDTLS_SSL_PROTO_TLS1_2) - if( ssl->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_2 ) - transform_expansion += block_size; -#endif /* MBEDTLS_SSL_PROTO_TLS1_1 || MBEDTLS_SSL_PROTO_TLS1_2 */ - - break; - - default: - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - -#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) - if( transform->out_cid_len != 0 ) - transform_expansion += MBEDTLS_SSL_MAX_CID_EXPANSION; -#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ - - return( (int)( out_hdr_len + transform_expansion ) ); -} - -#if defined(MBEDTLS_SSL_RENEGOTIATION) -/* - * Check record counters and renegotiate if they're above the limit. - */ -static int ssl_check_ctr_renegotiate( mbedtls_ssl_context *ssl ) -{ - size_t ep_len = mbedtls_ssl_ep_len( ssl ); - int in_ctr_cmp; - int out_ctr_cmp; - - if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER || - ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_PENDING || - ssl->conf->disable_renegotiation == MBEDTLS_SSL_RENEGOTIATION_DISABLED ) - { - return( 0 ); - } - - in_ctr_cmp = memcmp( ssl->in_ctr + ep_len, - ssl->conf->renego_period + ep_len, 8 - ep_len ); - out_ctr_cmp = memcmp( ssl->cur_out_ctr + ep_len, - ssl->conf->renego_period + ep_len, 8 - ep_len ); - - if( in_ctr_cmp <= 0 && out_ctr_cmp <= 0 ) - { - return( 0 ); - } - - MBEDTLS_SSL_DEBUG_MSG( 1, ( "record counter limit reached: renegotiate" ) ); - return( mbedtls_ssl_renegotiate( ssl ) ); -} -#endif /* MBEDTLS_SSL_RENEGOTIATION */ - -/* - * Receive application data decrypted from the SSL layer - */ -int mbedtls_ssl_read( mbedtls_ssl_context *ssl, unsigned char *buf, size_t len ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - size_t n; - - if( ssl == NULL || ssl->conf == NULL ) - return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> read" ) ); - -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { - if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 ) - return( ret ); - - if( ssl->handshake != NULL && - ssl->handshake->retransmit_state == MBEDTLS_SSL_RETRANS_SENDING ) - { - if( ( ret = mbedtls_ssl_flight_transmit( ssl ) ) != 0 ) - return( ret ); - } - } -#endif - - /* - * Check if renegotiation is necessary and/or handshake is - * in process. If yes, perform/continue, and fall through - * if an unexpected packet is received while the client - * is waiting for the ServerHello. - * - * (There is no equivalent to the last condition on - * the server-side as it is not treated as within - * a handshake while waiting for the ClientHello - * after a renegotiation request.) - */ - -#if defined(MBEDTLS_SSL_RENEGOTIATION) - ret = ssl_check_ctr_renegotiate( ssl ); - if( ret != MBEDTLS_ERR_SSL_WAITING_SERVER_HELLO_RENEGO && - ret != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "ssl_check_ctr_renegotiate", ret ); - return( ret ); - } -#endif - - if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER ) - { - ret = mbedtls_ssl_handshake( ssl ); - if( ret != MBEDTLS_ERR_SSL_WAITING_SERVER_HELLO_RENEGO && - ret != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_handshake", ret ); - return( ret ); - } - } - - /* Loop as long as no application data record is available */ - while( ssl->in_offt == NULL ) - { - /* Start timer if not already running */ - if( ssl->f_get_timer != NULL && - ssl->f_get_timer( ssl->p_timer ) == -1 ) - { - mbedtls_ssl_set_timer( ssl, ssl->conf->read_timeout ); - } - - if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 ) - { - if( ret == MBEDTLS_ERR_SSL_CONN_EOF ) - return( 0 ); - - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret ); - return( ret ); - } - - if( ssl->in_msglen == 0 && - ssl->in_msgtype == MBEDTLS_SSL_MSG_APPLICATION_DATA ) - { - /* - * OpenSSL sends empty messages to randomize the IV - */ - if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 ) - { - if( ret == MBEDTLS_ERR_SSL_CONN_EOF ) - return( 0 ); - - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret ); - return( ret ); - } - } - - if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "received handshake message" ) ); - - /* - * - For client-side, expect SERVER_HELLO_REQUEST. - * - For server-side, expect CLIENT_HELLO. - * - Fail (TLS) or silently drop record (DTLS) in other cases. - */ - -#if defined(MBEDTLS_SSL_CLI_C) - if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT && - ( ssl->in_msg[0] != MBEDTLS_SSL_HS_HELLO_REQUEST || - ssl->in_hslen != mbedtls_ssl_hs_hdr_len( ssl ) ) ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "handshake received (not HelloRequest)" ) ); - - /* With DTLS, drop the packet (probably from last handshake) */ -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { - continue; - } -#endif - return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE ); - } -#endif /* MBEDTLS_SSL_CLI_C */ - -#if defined(MBEDTLS_SSL_SRV_C) - if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER && - ssl->in_msg[0] != MBEDTLS_SSL_HS_CLIENT_HELLO ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "handshake received (not ClientHello)" ) ); - - /* With DTLS, drop the packet (probably from last handshake) */ -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { - continue; - } -#endif - return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE ); - } -#endif /* MBEDTLS_SSL_SRV_C */ - -#if defined(MBEDTLS_SSL_RENEGOTIATION) - /* Determine whether renegotiation attempt should be accepted */ - if( ! ( ssl->conf->disable_renegotiation == MBEDTLS_SSL_RENEGOTIATION_DISABLED || - ( ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION && - ssl->conf->allow_legacy_renegotiation == - MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION ) ) ) - { - /* - * Accept renegotiation request - */ - - /* DTLS clients need to know renego is server-initiated */ -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && - ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT ) - { - ssl->renego_status = MBEDTLS_SSL_RENEGOTIATION_PENDING; - } -#endif - ret = mbedtls_ssl_start_renegotiation( ssl ); - if( ret != MBEDTLS_ERR_SSL_WAITING_SERVER_HELLO_RENEGO && - ret != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_start_renegotiation", - ret ); - return( ret ); - } - } - else -#endif /* MBEDTLS_SSL_RENEGOTIATION */ - { - /* - * Refuse renegotiation - */ - - MBEDTLS_SSL_DEBUG_MSG( 3, ( "refusing renegotiation, sending alert" ) ); - -#if defined(MBEDTLS_SSL_PROTO_SSL3) - if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ) - { - /* SSLv3 does not have a "no_renegotiation" warning, so - we send a fatal alert and abort the connection. */ - mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, - MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE ); - return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE ); - } - else -#endif /* MBEDTLS_SSL_PROTO_SSL3 */ -#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \ - defined(MBEDTLS_SSL_PROTO_TLS1_2) - if( ssl->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_1 ) - { - if( ( ret = mbedtls_ssl_send_alert_message( ssl, - MBEDTLS_SSL_ALERT_LEVEL_WARNING, - MBEDTLS_SSL_ALERT_MSG_NO_RENEGOTIATION ) ) != 0 ) - { - return( ret ); - } - } - else -#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || - MBEDTLS_SSL_PROTO_TLS1_2 */ - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); - } - } - - /* At this point, we don't know whether the renegotiation has been - * completed or not. The cases to consider are the following: - * 1) The renegotiation is complete. In this case, no new record - * has been read yet. - * 2) The renegotiation is incomplete because the client received - * an application data record while awaiting the ServerHello. - * 3) The renegotiation is incomplete because the client received - * a non-handshake, non-application data message while awaiting - * the ServerHello. - * In each of these case, looping will be the proper action: - * - For 1), the next iteration will read a new record and check - * if it's application data. - * - For 2), the loop condition isn't satisfied as application data - * is present, hence continue is the same as break - * - For 3), the loop condition is satisfied and read_record - * will re-deliver the message that was held back by the client - * when expecting the ServerHello. - */ - continue; - } -#if defined(MBEDTLS_SSL_RENEGOTIATION) - else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_PENDING ) - { - if( ssl->conf->renego_max_records >= 0 ) - { - if( ++ssl->renego_records_seen > ssl->conf->renego_max_records ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "renegotiation requested, " - "but not honored by client" ) ); - return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE ); - } - } - } -#endif /* MBEDTLS_SSL_RENEGOTIATION */ - - /* Fatal and closure alerts handled by mbedtls_ssl_read_record() */ - if( ssl->in_msgtype == MBEDTLS_SSL_MSG_ALERT ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "ignoring non-fatal non-closure alert" ) ); - return( MBEDTLS_ERR_SSL_WANT_READ ); - } - - if( ssl->in_msgtype != MBEDTLS_SSL_MSG_APPLICATION_DATA ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad application data message" ) ); - return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE ); - } - - ssl->in_offt = ssl->in_msg; - - /* We're going to return something now, cancel timer, - * except if handshake (renegotiation) is in progress */ - if( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER ) - mbedtls_ssl_set_timer( ssl, 0 ); - -#if defined(MBEDTLS_SSL_PROTO_DTLS) - /* If we requested renego but received AppData, resend HelloRequest. - * Do it now, after setting in_offt, to avoid taking this branch - * again if ssl_write_hello_request() returns WANT_WRITE */ -#if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_RENEGOTIATION) - if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER && - ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_PENDING ) - { - if( ( ret = mbedtls_ssl_resend_hello_request( ssl ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_resend_hello_request", - ret ); - return( ret ); - } - } -#endif /* MBEDTLS_SSL_SRV_C && MBEDTLS_SSL_RENEGOTIATION */ -#endif /* MBEDTLS_SSL_PROTO_DTLS */ - } - - n = ( len < ssl->in_msglen ) - ? len : ssl->in_msglen; - - memcpy( buf, ssl->in_offt, n ); - ssl->in_msglen -= n; - - /* Zeroising the plaintext buffer to erase unused application data - from the memory. */ - mbedtls_platform_zeroize( ssl->in_offt, n ); - - if( ssl->in_msglen == 0 ) - { - /* all bytes consumed */ - ssl->in_offt = NULL; - ssl->keep_current_message = 0; - } - else - { - /* more data available */ - ssl->in_offt += n; - } - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= read" ) ); - - return( (int) n ); -} - -/* - * Send application data to be encrypted by the SSL layer, taking care of max - * fragment length and buffer size. - * - * According to RFC 5246 Section 6.2.1: - * - * Zero-length fragments of Application data MAY be sent as they are - * potentially useful as a traffic analysis countermeasure. - * - * Therefore, it is possible that the input message length is 0 and the - * corresponding return code is 0 on success. - */ -static int ssl_write_real( mbedtls_ssl_context *ssl, - const unsigned char *buf, size_t len ) -{ - int ret = mbedtls_ssl_get_max_out_record_payload( ssl ); - const size_t max_len = (size_t) ret; - - if( ret < 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_get_max_out_record_payload", ret ); - return( ret ); - } - - if( len > max_len ) - { -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "fragment larger than the (negotiated) " - "maximum fragment length: %" MBEDTLS_PRINTF_SIZET - " > %" MBEDTLS_PRINTF_SIZET, - len, max_len ) ); - return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); - } - else -#endif - len = max_len; - } - - if( ssl->out_left != 0 ) - { - /* - * The user has previously tried to send the data and - * MBEDTLS_ERR_SSL_WANT_WRITE or the message was only partially - * written. In this case, we expect the high-level write function - * (e.g. mbedtls_ssl_write()) to be called with the same parameters - */ - if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_flush_output", ret ); - return( ret ); - } - } - else - { - /* - * The user is trying to send a message the first time, so we need to - * copy the data into the internal buffers and setup the data structure - * to keep track of partial writes - */ - ssl->out_msglen = len; - ssl->out_msgtype = MBEDTLS_SSL_MSG_APPLICATION_DATA; - memcpy( ssl->out_msg, buf, len ); - - if( ( ret = mbedtls_ssl_write_record( ssl, SSL_FORCE_FLUSH ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret ); - return( ret ); - } - } - - return( (int) len ); -} - -/* - * Write application data, doing 1/n-1 splitting if necessary. - * - * With non-blocking I/O, ssl_write_real() may return WANT_WRITE, - * then the caller will call us again with the same arguments, so - * remember whether we already did the split or not. - */ -#if defined(MBEDTLS_SSL_CBC_RECORD_SPLITTING) -static int ssl_write_split( mbedtls_ssl_context *ssl, - const unsigned char *buf, size_t len ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - - if( ssl->conf->cbc_record_splitting == - MBEDTLS_SSL_CBC_RECORD_SPLITTING_DISABLED || - len <= 1 || - ssl->minor_ver > MBEDTLS_SSL_MINOR_VERSION_1 || - mbedtls_cipher_get_cipher_mode( &ssl->transform_out->cipher_ctx_enc ) - != MBEDTLS_MODE_CBC ) - { - return( ssl_write_real( ssl, buf, len ) ); - } - - if( ssl->split_done == 0 ) - { - if( ( ret = ssl_write_real( ssl, buf, 1 ) ) <= 0 ) - return( ret ); - ssl->split_done = 1; - } - - if( ( ret = ssl_write_real( ssl, buf + 1, len - 1 ) ) <= 0 ) - return( ret ); - ssl->split_done = 0; - - return( ret + 1 ); -} -#endif /* MBEDTLS_SSL_CBC_RECORD_SPLITTING */ - -/* - * Write application data (public-facing wrapper) - */ -int mbedtls_ssl_write( mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write" ) ); - - if( ssl == NULL || ssl->conf == NULL ) - return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); - -#if defined(MBEDTLS_SSL_RENEGOTIATION) - if( ( ret = ssl_check_ctr_renegotiate( ssl ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "ssl_check_ctr_renegotiate", ret ); - return( ret ); - } -#endif - - if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER ) - { - if( ( ret = mbedtls_ssl_handshake( ssl ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_handshake", ret ); - return( ret ); - } - } - -#if defined(MBEDTLS_SSL_CBC_RECORD_SPLITTING) - ret = ssl_write_split( ssl, buf, len ); -#else - ret = ssl_write_real( ssl, buf, len ); -#endif - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write" ) ); - - return( ret ); -} - -/* - * Notify the peer that the connection is being closed - */ -int mbedtls_ssl_close_notify( mbedtls_ssl_context *ssl ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - - if( ssl == NULL || ssl->conf == NULL ) - return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write close notify" ) ); - - if( ssl->out_left != 0 ) - return( mbedtls_ssl_flush_output( ssl ) ); - - if( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER ) - { - if( ( ret = mbedtls_ssl_send_alert_message( ssl, - MBEDTLS_SSL_ALERT_LEVEL_WARNING, - MBEDTLS_SSL_ALERT_MSG_CLOSE_NOTIFY ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_send_alert_message", ret ); - return( ret ); - } - } - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write close notify" ) ); - - return( 0 ); -} - -void mbedtls_ssl_transform_free( mbedtls_ssl_transform *transform ) -{ - if( transform == NULL ) - return; - -#if defined(MBEDTLS_ZLIB_SUPPORT) - deflateEnd( &transform->ctx_deflate ); - inflateEnd( &transform->ctx_inflate ); -#endif - - mbedtls_cipher_free( &transform->cipher_ctx_enc ); - mbedtls_cipher_free( &transform->cipher_ctx_dec ); - -#if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC) - mbedtls_md_free( &transform->md_ctx_enc ); - mbedtls_md_free( &transform->md_ctx_dec ); -#endif - - mbedtls_platform_zeroize( transform, sizeof( mbedtls_ssl_transform ) ); -} - -#if defined(MBEDTLS_SSL_PROTO_DTLS) - -void mbedtls_ssl_buffering_free( mbedtls_ssl_context *ssl ) -{ - unsigned offset; - mbedtls_ssl_handshake_params * const hs = ssl->handshake; - - if( hs == NULL ) - return; - - ssl_free_buffered_record( ssl ); - - for( offset = 0; offset < MBEDTLS_SSL_MAX_BUFFERED_HS; offset++ ) - ssl_buffering_free_slot( ssl, offset ); -} - -static void ssl_buffering_free_slot( mbedtls_ssl_context *ssl, - uint8_t slot ) -{ - mbedtls_ssl_handshake_params * const hs = ssl->handshake; - mbedtls_ssl_hs_buffer * const hs_buf = &hs->buffering.hs[slot]; - - if( slot >= MBEDTLS_SSL_MAX_BUFFERED_HS ) - return; - - if( hs_buf->is_valid == 1 ) - { - hs->buffering.total_bytes_buffered -= hs_buf->data_len; - mbedtls_platform_zeroize( hs_buf->data, hs_buf->data_len ); - mbedtls_free( hs_buf->data ); - memset( hs_buf, 0, sizeof( mbedtls_ssl_hs_buffer ) ); - } -} - -#endif /* MBEDTLS_SSL_PROTO_DTLS */ - -/* - * Convert version numbers to/from wire format - * and, for DTLS, to/from TLS equivalent. - * - * For TLS this is the identity. - * For DTLS, use 1's complement (v -> 255 - v, and then map as follows: - * 1.0 <-> 3.2 (DTLS 1.0 is based on TLS 1.1) - * 1.x <-> 3.x+1 for x != 0 (DTLS 1.2 based on TLS 1.2) - */ -void mbedtls_ssl_write_version( int major, int minor, int transport, - unsigned char ver[2] ) -{ -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { - if( minor == MBEDTLS_SSL_MINOR_VERSION_2 ) - --minor; /* DTLS 1.0 stored as TLS 1.1 internally */ - - ver[0] = (unsigned char)( 255 - ( major - 2 ) ); - ver[1] = (unsigned char)( 255 - ( minor - 1 ) ); - } - else -#else - ((void) transport); -#endif - { - ver[0] = (unsigned char) major; - ver[1] = (unsigned char) minor; - } -} - -void mbedtls_ssl_read_version( int *major, int *minor, int transport, - const unsigned char ver[2] ) -{ -#if defined(MBEDTLS_SSL_PROTO_DTLS) - if( transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) - { - *major = 255 - ver[0] + 2; - *minor = 255 - ver[1] + 1; - - if( *minor == MBEDTLS_SSL_MINOR_VERSION_1 ) - ++*minor; /* DTLS 1.0 stored as TLS 1.1 internally */ - } - else -#else - ((void) transport); -#endif - { - *major = ver[0]; - *minor = ver[1]; - } -} - -#endif /* MBEDTLS_SSL_TLS_C */ |