diff options
Diffstat (limited to 'lib/mbedtls-2.27.0/library/ssl_ticket.c')
| -rw-r--r-- | lib/mbedtls-2.27.0/library/ssl_ticket.c | 405 |
1 files changed, 405 insertions, 0 deletions
diff --git a/lib/mbedtls-2.27.0/library/ssl_ticket.c b/lib/mbedtls-2.27.0/library/ssl_ticket.c new file mode 100644 index 0000000..626d137 --- /dev/null +++ b/lib/mbedtls-2.27.0/library/ssl_ticket.c @@ -0,0 +1,405 @@ +/* + * TLS server tickets callbacks implementation + * + * 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. + */ + +#include "common.h" + +#if defined(MBEDTLS_SSL_TICKET_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_internal.h" +#include "mbedtls/ssl_ticket.h" +#include "mbedtls/error.h" +#include "mbedtls/platform_util.h" + +#include <string.h> + +/* + * Initialze context + */ +void mbedtls_ssl_ticket_init( mbedtls_ssl_ticket_context *ctx ) +{ + memset( ctx, 0, sizeof( mbedtls_ssl_ticket_context ) ); + +#if defined(MBEDTLS_THREADING_C) + mbedtls_mutex_init( &ctx->mutex ); +#endif +} + +#define MAX_KEY_BYTES 32 /* 256 bits */ + +#define TICKET_KEY_NAME_BYTES 4 +#define TICKET_IV_BYTES 12 +#define TICKET_CRYPT_LEN_BYTES 2 +#define TICKET_AUTH_TAG_BYTES 16 + +#define TICKET_MIN_LEN ( TICKET_KEY_NAME_BYTES + \ + TICKET_IV_BYTES + \ + TICKET_CRYPT_LEN_BYTES + \ + TICKET_AUTH_TAG_BYTES ) +#define TICKET_ADD_DATA_LEN ( TICKET_KEY_NAME_BYTES + \ + TICKET_IV_BYTES + \ + TICKET_CRYPT_LEN_BYTES ) + +/* + * Generate/update a key + */ +static int ssl_ticket_gen_key( mbedtls_ssl_ticket_context *ctx, + unsigned char index ) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + unsigned char buf[MAX_KEY_BYTES]; + mbedtls_ssl_ticket_key *key = ctx->keys + index; + +#if defined(MBEDTLS_HAVE_TIME) + key->generation_time = (uint32_t) mbedtls_time( NULL ); +#endif + + if( ( ret = ctx->f_rng( ctx->p_rng, key->name, sizeof( key->name ) ) ) != 0 ) + return( ret ); + + if( ( ret = ctx->f_rng( ctx->p_rng, buf, sizeof( buf ) ) ) != 0 ) + return( ret ); + + /* With GCM and CCM, same context can encrypt & decrypt */ + ret = mbedtls_cipher_setkey( &key->ctx, buf, + mbedtls_cipher_get_key_bitlen( &key->ctx ), + MBEDTLS_ENCRYPT ); + + mbedtls_platform_zeroize( buf, sizeof( buf ) ); + + return( ret ); +} + +/* + * Rotate/generate keys if necessary + */ +static int ssl_ticket_update_keys( mbedtls_ssl_ticket_context *ctx ) +{ +#if !defined(MBEDTLS_HAVE_TIME) + ((void) ctx); +#else + if( ctx->ticket_lifetime != 0 ) + { + uint32_t current_time = (uint32_t) mbedtls_time( NULL ); + uint32_t key_time = ctx->keys[ctx->active].generation_time; + + if( current_time >= key_time && + current_time - key_time < ctx->ticket_lifetime ) + { + return( 0 ); + } + + ctx->active = 1 - ctx->active; + + return( ssl_ticket_gen_key( ctx, ctx->active ) ); + } + else +#endif /* MBEDTLS_HAVE_TIME */ + return( 0 ); +} + +/* + * Setup context for actual use + */ +int mbedtls_ssl_ticket_setup( mbedtls_ssl_ticket_context *ctx, + int (*f_rng)(void *, unsigned char *, size_t), void *p_rng, + mbedtls_cipher_type_t cipher, + uint32_t lifetime ) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + const mbedtls_cipher_info_t *cipher_info; + + ctx->f_rng = f_rng; + ctx->p_rng = p_rng; + + ctx->ticket_lifetime = lifetime; + + cipher_info = mbedtls_cipher_info_from_type( cipher); + if( cipher_info == NULL ) + return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); + + if( cipher_info->mode != MBEDTLS_MODE_GCM && + cipher_info->mode != MBEDTLS_MODE_CCM ) + { + return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); + } + + if( cipher_info->key_bitlen > 8 * MAX_KEY_BYTES ) + return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); + +#if defined(MBEDTLS_USE_PSA_CRYPTO) + ret = mbedtls_cipher_setup_psa( &ctx->keys[0].ctx, + cipher_info, TICKET_AUTH_TAG_BYTES ); + if( ret != 0 && ret != MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE ) + return( ret ); + /* We don't yet expect to support all ciphers through PSA, + * so allow fallback to ordinary mbedtls_cipher_setup(). */ + if( ret == MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE ) +#endif /* MBEDTLS_USE_PSA_CRYPTO */ + if( ( ret = mbedtls_cipher_setup( &ctx->keys[0].ctx, cipher_info ) ) != 0 ) + return( ret ); + +#if defined(MBEDTLS_USE_PSA_CRYPTO) + ret = mbedtls_cipher_setup_psa( &ctx->keys[1].ctx, + cipher_info, TICKET_AUTH_TAG_BYTES ); + if( ret != 0 && ret != MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE ) + return( ret ); + if( ret == MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE ) +#endif /* MBEDTLS_USE_PSA_CRYPTO */ + if( ( ret = mbedtls_cipher_setup( &ctx->keys[1].ctx, cipher_info ) ) != 0 ) + return( ret ); + + if( ( ret = ssl_ticket_gen_key( ctx, 0 ) ) != 0 || + ( ret = ssl_ticket_gen_key( ctx, 1 ) ) != 0 ) + { + return( ret ); + } + + return( 0 ); +} + +/* + * Create session ticket, with the following structure: + * + * struct { + * opaque key_name[4]; + * opaque iv[12]; + * opaque encrypted_state<0..2^16-1>; + * opaque tag[16]; + * } ticket; + * + * The key_name, iv, and length of encrypted_state are the additional + * authenticated data. + */ + +int mbedtls_ssl_ticket_write( void *p_ticket, + const mbedtls_ssl_session *session, + unsigned char *start, + const unsigned char *end, + size_t *tlen, + uint32_t *ticket_lifetime ) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + mbedtls_ssl_ticket_context *ctx = p_ticket; + mbedtls_ssl_ticket_key *key; + unsigned char *key_name = start; + unsigned char *iv = start + TICKET_KEY_NAME_BYTES; + unsigned char *state_len_bytes = iv + TICKET_IV_BYTES; + unsigned char *state = state_len_bytes + TICKET_CRYPT_LEN_BYTES; + size_t clear_len, ciph_len; + + *tlen = 0; + + if( ctx == NULL || ctx->f_rng == NULL ) + return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); + + /* We need at least 4 bytes for key_name, 12 for IV, 2 for len 16 for tag, + * in addition to session itself, that will be checked when writing it. */ + MBEDTLS_SSL_CHK_BUF_PTR( start, end, TICKET_MIN_LEN ); + +#if defined(MBEDTLS_THREADING_C) + if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 ) + return( ret ); +#endif + + if( ( ret = ssl_ticket_update_keys( ctx ) ) != 0 ) + goto cleanup; + + key = &ctx->keys[ctx->active]; + + *ticket_lifetime = ctx->ticket_lifetime; + + memcpy( key_name, key->name, TICKET_KEY_NAME_BYTES ); + + if( ( ret = ctx->f_rng( ctx->p_rng, iv, TICKET_IV_BYTES ) ) != 0 ) + goto cleanup; + + /* Dump session state */ + if( ( ret = mbedtls_ssl_session_save( session, + state, end - state, + &clear_len ) ) != 0 || + (unsigned long) clear_len > 65535 ) + { + goto cleanup; + } + state_len_bytes[0] = ( clear_len >> 8 ) & 0xff; + state_len_bytes[1] = ( clear_len ) & 0xff; + + /* Encrypt and authenticate */ + if( ( ret = mbedtls_cipher_auth_encrypt_ext( &key->ctx, + iv, TICKET_IV_BYTES, + /* Additional data: key name, IV and length */ + key_name, TICKET_ADD_DATA_LEN, + state, clear_len, + state, end - state, &ciph_len, + TICKET_AUTH_TAG_BYTES ) ) != 0 ) + { + goto cleanup; + } + if( ciph_len != clear_len + TICKET_AUTH_TAG_BYTES ) + { + ret = MBEDTLS_ERR_SSL_INTERNAL_ERROR; + goto cleanup; + } + + *tlen = TICKET_MIN_LEN + ciph_len - TICKET_AUTH_TAG_BYTES; + +cleanup: +#if defined(MBEDTLS_THREADING_C) + if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 ) + return( MBEDTLS_ERR_THREADING_MUTEX_ERROR ); +#endif + + return( ret ); +} + +/* + * Select key based on name + */ +static mbedtls_ssl_ticket_key *ssl_ticket_select_key( + mbedtls_ssl_ticket_context *ctx, + const unsigned char name[4] ) +{ + unsigned char i; + + for( i = 0; i < sizeof( ctx->keys ) / sizeof( *ctx->keys ); i++ ) + if( memcmp( name, ctx->keys[i].name, 4 ) == 0 ) + return( &ctx->keys[i] ); + + return( NULL ); +} + +/* + * Load session ticket (see mbedtls_ssl_ticket_write for structure) + */ +int mbedtls_ssl_ticket_parse( void *p_ticket, + mbedtls_ssl_session *session, + unsigned char *buf, + size_t len ) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + mbedtls_ssl_ticket_context *ctx = p_ticket; + mbedtls_ssl_ticket_key *key; + unsigned char *key_name = buf; + unsigned char *iv = buf + TICKET_KEY_NAME_BYTES; + unsigned char *enc_len_p = iv + TICKET_IV_BYTES; + unsigned char *ticket = enc_len_p + TICKET_CRYPT_LEN_BYTES; + size_t enc_len, clear_len; + + if( ctx == NULL || ctx->f_rng == NULL ) + return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); + + if( len < TICKET_MIN_LEN ) + return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); + +#if defined(MBEDTLS_THREADING_C) + if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 ) + return( ret ); +#endif + + if( ( ret = ssl_ticket_update_keys( ctx ) ) != 0 ) + goto cleanup; + + enc_len = ( enc_len_p[0] << 8 ) | enc_len_p[1]; + + if( len != TICKET_MIN_LEN + enc_len ) + { + ret = MBEDTLS_ERR_SSL_BAD_INPUT_DATA; + goto cleanup; + } + + /* Select key */ + if( ( key = ssl_ticket_select_key( ctx, key_name ) ) == NULL ) + { + /* We can't know for sure but this is a likely option unless we're + * under attack - this is only informative anyway */ + ret = MBEDTLS_ERR_SSL_SESSION_TICKET_EXPIRED; + goto cleanup; + } + + /* Decrypt and authenticate */ + if( ( ret = mbedtls_cipher_auth_decrypt_ext( &key->ctx, + iv, TICKET_IV_BYTES, + /* Additional data: key name, IV and length */ + key_name, TICKET_ADD_DATA_LEN, + ticket, enc_len + TICKET_AUTH_TAG_BYTES, + ticket, enc_len, &clear_len, + TICKET_AUTH_TAG_BYTES ) ) != 0 ) + { + if( ret == MBEDTLS_ERR_CIPHER_AUTH_FAILED ) + ret = MBEDTLS_ERR_SSL_INVALID_MAC; + + goto cleanup; + } + if( clear_len != enc_len ) + { + ret = MBEDTLS_ERR_SSL_INTERNAL_ERROR; + goto cleanup; + } + + /* Actually load session */ + if( ( ret = mbedtls_ssl_session_load( session, ticket, clear_len ) ) != 0 ) + goto cleanup; + +#if defined(MBEDTLS_HAVE_TIME) + { + /* Check for expiration */ + mbedtls_time_t current_time = mbedtls_time( NULL ); + + if( current_time < session->start || + (uint32_t)( current_time - session->start ) > ctx->ticket_lifetime ) + { + ret = MBEDTLS_ERR_SSL_SESSION_TICKET_EXPIRED; + goto cleanup; + } + } +#endif + +cleanup: +#if defined(MBEDTLS_THREADING_C) + if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 ) + return( MBEDTLS_ERR_THREADING_MUTEX_ERROR ); +#endif + + return( ret ); +} + +/* + * Free context + */ +void mbedtls_ssl_ticket_free( mbedtls_ssl_ticket_context *ctx ) +{ + mbedtls_cipher_free( &ctx->keys[0].ctx ); + mbedtls_cipher_free( &ctx->keys[1].ctx ); + +#if defined(MBEDTLS_THREADING_C) + mbedtls_mutex_free( &ctx->mutex ); +#endif + + mbedtls_platform_zeroize( ctx, sizeof( mbedtls_ssl_ticket_context ) ); +} + +#endif /* MBEDTLS_SSL_TICKET_C */ |