/* * X.509 Certidicate Revocation List (CRL) parsing * * 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 ITU-T X.509 standard defines a certificate format for PKI. * * http://www.ietf.org/rfc/rfc5280.txt (Certificates and CRLs) * http://www.ietf.org/rfc/rfc3279.txt (Alg IDs for CRLs) * http://www.ietf.org/rfc/rfc2986.txt (CSRs, aka PKCS#10) * * http://www.itu.int/ITU-T/studygroups/com17/languages/X.680-0207.pdf * http://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf */ #include "common.h" #if defined(MBEDTLS_X509_CRL_PARSE_C) #include "mbedtls/x509_crl.h" #include "mbedtls/error.h" #include "mbedtls/oid.h" #include "mbedtls/platform_util.h" #include <string.h> #if defined(MBEDTLS_PEM_PARSE_C) #include "mbedtls/pem.h" #endif #if defined(MBEDTLS_PLATFORM_C) #include "mbedtls/platform.h" #else #include <stdlib.h> #include <stdio.h> #define mbedtls_free free #define mbedtls_calloc calloc #define mbedtls_snprintf snprintf #endif #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32) #include <windows.h> #else #include <time.h> #endif #if defined(MBEDTLS_FS_IO) || defined(EFIX64) || defined(EFI32) #include <stdio.h> #endif /* * Version ::= INTEGER { v1(0), v2(1) } */ static int x509_crl_get_version( unsigned char **p, const unsigned char *end, int *ver ) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; if( ( ret = mbedtls_asn1_get_int( p, end, ver ) ) != 0 ) { if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) { *ver = 0; return( 0 ); } return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_VERSION, ret ) ); } return( 0 ); } /* * X.509 CRL v2 extensions * * We currently don't parse any extension's content, but we do check that the * list of extensions is well-formed and abort on critical extensions (that * are unsupported as we don't support any extension so far) */ static int x509_get_crl_ext( unsigned char **p, const unsigned char *end, mbedtls_x509_buf *ext ) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; if( *p == end ) return( 0 ); /* * crlExtensions [0] EXPLICIT Extensions OPTIONAL * -- if present, version MUST be v2 */ if( ( ret = mbedtls_x509_get_ext( p, end, ext, 0 ) ) != 0 ) return( ret ); end = ext->p + ext->len; while( *p < end ) { /* * Extension ::= SEQUENCE { * extnID OBJECT IDENTIFIER, * critical BOOLEAN DEFAULT FALSE, * extnValue OCTET STRING } */ int is_critical = 0; const unsigned char *end_ext_data; size_t len; /* Get enclosing sequence tag */ if( ( ret = mbedtls_asn1_get_tag( p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret ) ); end_ext_data = *p + len; /* Get OID (currently ignored) */ if( ( ret = mbedtls_asn1_get_tag( p, end_ext_data, &len, MBEDTLS_ASN1_OID ) ) != 0 ) { return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret ) ); } *p += len; /* Get optional critical */ if( ( ret = mbedtls_asn1_get_bool( p, end_ext_data, &is_critical ) ) != 0 && ( ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) ) { return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret ) ); } /* Data should be octet string type */ if( ( ret = mbedtls_asn1_get_tag( p, end_ext_data, &len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 ) return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret ) ); /* Ignore data so far and just check its length */ *p += len; if( *p != end_ext_data ) return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_EXTENSIONS, MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) ); /* Abort on (unsupported) critical extensions */ if( is_critical ) return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_EXTENSIONS, MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) ); } if( *p != end ) return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_EXTENSIONS, MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) ); return( 0 ); } /* * X.509 CRL v2 entry extensions (no extensions parsed yet.) */ static int x509_get_crl_entry_ext( unsigned char **p, const unsigned char *end, mbedtls_x509_buf *ext ) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t len = 0; /* OPTIONAL */ if( end <= *p ) return( 0 ); ext->tag = **p; ext->p = *p; /* * Get CRL-entry extension sequence header * crlEntryExtensions Extensions OPTIONAL -- if present, MUST be v2 */ if( ( ret = mbedtls_asn1_get_tag( p, end, &ext->len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) { if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) { ext->p = NULL; return( 0 ); } return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret ) ); } end = *p + ext->len; if( end != *p + ext->len ) return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_EXTENSIONS, MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) ); while( *p < end ) { if( ( ret = mbedtls_asn1_get_tag( p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret ) ); *p += len; } if( *p != end ) return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_EXTENSIONS, MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) ); return( 0 ); } /* * X.509 CRL Entries */ static int x509_get_entries( unsigned char **p, const unsigned char *end, mbedtls_x509_crl_entry *entry ) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t entry_len; mbedtls_x509_crl_entry *cur_entry = entry; if( *p == end ) return( 0 ); if( ( ret = mbedtls_asn1_get_tag( p, end, &entry_len, MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED ) ) != 0 ) { if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) return( 0 ); return( ret ); } end = *p + entry_len; while( *p < end ) { size_t len2; const unsigned char *end2; cur_entry->raw.tag = **p; if( ( ret = mbedtls_asn1_get_tag( p, end, &len2, MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED ) ) != 0 ) { return( ret ); } cur_entry->raw.p = *p; cur_entry->raw.len = len2; end2 = *p + len2; if( ( ret = mbedtls_x509_get_serial( p, end2, &cur_entry->serial ) ) != 0 ) return( ret ); if( ( ret = mbedtls_x509_get_time( p, end2, &cur_entry->revocation_date ) ) != 0 ) return( ret ); if( ( ret = x509_get_crl_entry_ext( p, end2, &cur_entry->entry_ext ) ) != 0 ) return( ret ); if( *p < end ) { cur_entry->next = mbedtls_calloc( 1, sizeof( mbedtls_x509_crl_entry ) ); if( cur_entry->next == NULL ) return( MBEDTLS_ERR_X509_ALLOC_FAILED ); cur_entry = cur_entry->next; } } return( 0 ); } /* * Parse one CRLs in DER format and append it to the chained list */ int mbedtls_x509_crl_parse_der( mbedtls_x509_crl *chain, const unsigned char *buf, size_t buflen ) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t len; unsigned char *p = NULL, *end = NULL; mbedtls_x509_buf sig_params1, sig_params2, sig_oid2; mbedtls_x509_crl *crl = chain; /* * Check for valid input */ if( crl == NULL || buf == NULL ) return( MBEDTLS_ERR_X509_BAD_INPUT_DATA ); memset( &sig_params1, 0, sizeof( mbedtls_x509_buf ) ); memset( &sig_params2, 0, sizeof( mbedtls_x509_buf ) ); memset( &sig_oid2, 0, sizeof( mbedtls_x509_buf ) ); /* * Add new CRL on the end of the chain if needed. */ while( crl->version != 0 && crl->next != NULL ) crl = crl->next; if( crl->version != 0 && crl->next == NULL ) { crl->next = mbedtls_calloc( 1, sizeof( mbedtls_x509_crl ) ); if( crl->next == NULL ) { mbedtls_x509_crl_free( crl ); return( MBEDTLS_ERR_X509_ALLOC_FAILED ); } mbedtls_x509_crl_init( crl->next ); crl = crl->next; } /* * Copy raw DER-encoded CRL */ if( buflen == 0 ) return( MBEDTLS_ERR_X509_INVALID_FORMAT ); p = mbedtls_calloc( 1, buflen ); if( p == NULL ) return( MBEDTLS_ERR_X509_ALLOC_FAILED ); memcpy( p, buf, buflen ); crl->raw.p = p; crl->raw.len = buflen; end = p + buflen; /* * CertificateList ::= SEQUENCE { * tbsCertList TBSCertList, * signatureAlgorithm AlgorithmIdentifier, * signatureValue BIT STRING } */ if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) { mbedtls_x509_crl_free( crl ); return( MBEDTLS_ERR_X509_INVALID_FORMAT ); } if( len != (size_t) ( end - p ) ) { mbedtls_x509_crl_free( crl ); return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_FORMAT, MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) ); } /* * TBSCertList ::= SEQUENCE { */ crl->tbs.p = p; if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) { mbedtls_x509_crl_free( crl ); return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_FORMAT, ret ) ); } end = p + len; crl->tbs.len = end - crl->tbs.p; /* * Version ::= INTEGER OPTIONAL { v1(0), v2(1) } * -- if present, MUST be v2 * * signature AlgorithmIdentifier */ if( ( ret = x509_crl_get_version( &p, end, &crl->version ) ) != 0 || ( ret = mbedtls_x509_get_alg( &p, end, &crl->sig_oid, &sig_params1 ) ) != 0 ) { mbedtls_x509_crl_free( crl ); return( ret ); } if( crl->version < 0 || crl->version > 1 ) { mbedtls_x509_crl_free( crl ); return( MBEDTLS_ERR_X509_UNKNOWN_VERSION ); } crl->version++; if( ( ret = mbedtls_x509_get_sig_alg( &crl->sig_oid, &sig_params1, &crl->sig_md, &crl->sig_pk, &crl->sig_opts ) ) != 0 ) { mbedtls_x509_crl_free( crl ); return( MBEDTLS_ERR_X509_UNKNOWN_SIG_ALG ); } /* * issuer Name */ crl->issuer_raw.p = p; if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) { mbedtls_x509_crl_free( crl ); return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_FORMAT, ret ) ); } if( ( ret = mbedtls_x509_get_name( &p, p + len, &crl->issuer ) ) != 0 ) { mbedtls_x509_crl_free( crl ); return( ret ); } crl->issuer_raw.len = p - crl->issuer_raw.p; /* * thisUpdate Time * nextUpdate Time OPTIONAL */ if( ( ret = mbedtls_x509_get_time( &p, end, &crl->this_update ) ) != 0 ) { mbedtls_x509_crl_free( crl ); return( ret ); } if( ( ret = mbedtls_x509_get_time( &p, end, &crl->next_update ) ) != 0 ) { if( ret != ( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_DATE, MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) ) && ret != ( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_DATE, MBEDTLS_ERR_ASN1_OUT_OF_DATA ) ) ) { mbedtls_x509_crl_free( crl ); return( ret ); } } /* * revokedCertificates SEQUENCE OF SEQUENCE { * userCertificate CertificateSerialNumber, * revocationDate Time, * crlEntryExtensions Extensions OPTIONAL * -- if present, MUST be v2 * } OPTIONAL */ if( ( ret = x509_get_entries( &p, end, &crl->entry ) ) != 0 ) { mbedtls_x509_crl_free( crl ); return( ret ); } /* * crlExtensions EXPLICIT Extensions OPTIONAL * -- if present, MUST be v2 */ if( crl->version == 2 ) { ret = x509_get_crl_ext( &p, end, &crl->crl_ext ); if( ret != 0 ) { mbedtls_x509_crl_free( crl ); return( ret ); } } if( p != end ) { mbedtls_x509_crl_free( crl ); return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_FORMAT, MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) ); } end = crl->raw.p + crl->raw.len; /* * signatureAlgorithm AlgorithmIdentifier, * signatureValue BIT STRING */ if( ( ret = mbedtls_x509_get_alg( &p, end, &sig_oid2, &sig_params2 ) ) != 0 ) { mbedtls_x509_crl_free( crl ); return( ret ); } if( crl->sig_oid.len != sig_oid2.len || memcmp( crl->sig_oid.p, sig_oid2.p, crl->sig_oid.len ) != 0 || sig_params1.len != sig_params2.len || ( sig_params1.len != 0 && memcmp( sig_params1.p, sig_params2.p, sig_params1.len ) != 0 ) ) { mbedtls_x509_crl_free( crl ); return( MBEDTLS_ERR_X509_SIG_MISMATCH ); } if( ( ret = mbedtls_x509_get_sig( &p, end, &crl->sig ) ) != 0 ) { mbedtls_x509_crl_free( crl ); return( ret ); } if( p != end ) { mbedtls_x509_crl_free( crl ); return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_FORMAT, MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) ); } return( 0 ); } /* * Parse one or more CRLs and add them to the chained list */ int mbedtls_x509_crl_parse( mbedtls_x509_crl *chain, const unsigned char *buf, size_t buflen ) { #if defined(MBEDTLS_PEM_PARSE_C) int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t use_len = 0; mbedtls_pem_context pem; int is_pem = 0; if( chain == NULL || buf == NULL ) return( MBEDTLS_ERR_X509_BAD_INPUT_DATA ); do { mbedtls_pem_init( &pem ); // Avoid calling mbedtls_pem_read_buffer() on non-null-terminated // string if( buflen == 0 || buf[buflen - 1] != '\0' ) ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT; else ret = mbedtls_pem_read_buffer( &pem, "-----BEGIN X509 CRL-----", "-----END X509 CRL-----", buf, NULL, 0, &use_len ); if( ret == 0 ) { /* * Was PEM encoded */ is_pem = 1; buflen -= use_len; buf += use_len; if( ( ret = mbedtls_x509_crl_parse_der( chain, pem.buf, pem.buflen ) ) != 0 ) { mbedtls_pem_free( &pem ); return( ret ); } } else if( is_pem ) { mbedtls_pem_free( &pem ); return( ret ); } mbedtls_pem_free( &pem ); } /* In the PEM case, buflen is 1 at the end, for the terminated NULL byte. * And a valid CRL cannot be less than 1 byte anyway. */ while( is_pem && buflen > 1 ); if( is_pem ) return( 0 ); else #endif /* MBEDTLS_PEM_PARSE_C */ return( mbedtls_x509_crl_parse_der( chain, buf, buflen ) ); } #if defined(MBEDTLS_FS_IO) /* * Load one or more CRLs and add them to the chained list */ int mbedtls_x509_crl_parse_file( mbedtls_x509_crl *chain, const char *path ) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t n; unsigned char *buf; if( ( ret = mbedtls_pk_load_file( path, &buf, &n ) ) != 0 ) return( ret ); ret = mbedtls_x509_crl_parse( chain, buf, n ); mbedtls_platform_zeroize( buf, n ); mbedtls_free( buf ); return( ret ); } #endif /* MBEDTLS_FS_IO */ /* * Return an informational string about the certificate. */ #define BEFORE_COLON 14 #define BC "14" /* * Return an informational string about the CRL. */ int mbedtls_x509_crl_info( char *buf, size_t size, const char *prefix, const mbedtls_x509_crl *crl ) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t n; char *p; const mbedtls_x509_crl_entry *entry; p = buf; n = size; ret = mbedtls_snprintf( p, n, "%sCRL version : %d", prefix, crl->version ); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_snprintf( p, n, "\n%sissuer name : ", prefix ); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_x509_dn_gets( p, n, &crl->issuer ); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_snprintf( p, n, "\n%sthis update : " \ "%04d-%02d-%02d %02d:%02d:%02d", prefix, crl->this_update.year, crl->this_update.mon, crl->this_update.day, crl->this_update.hour, crl->this_update.min, crl->this_update.sec ); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_snprintf( p, n, "\n%snext update : " \ "%04d-%02d-%02d %02d:%02d:%02d", prefix, crl->next_update.year, crl->next_update.mon, crl->next_update.day, crl->next_update.hour, crl->next_update.min, crl->next_update.sec ); MBEDTLS_X509_SAFE_SNPRINTF; entry = &crl->entry; ret = mbedtls_snprintf( p, n, "\n%sRevoked certificates:", prefix ); MBEDTLS_X509_SAFE_SNPRINTF; while( entry != NULL && entry->raw.len != 0 ) { ret = mbedtls_snprintf( p, n, "\n%sserial number: ", prefix ); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_x509_serial_gets( p, n, &entry->serial ); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_snprintf( p, n, " revocation date: " \ "%04d-%02d-%02d %02d:%02d:%02d", entry->revocation_date.year, entry->revocation_date.mon, entry->revocation_date.day, entry->revocation_date.hour, entry->revocation_date.min, entry->revocation_date.sec ); MBEDTLS_X509_SAFE_SNPRINTF; entry = entry->next; } ret = mbedtls_snprintf( p, n, "\n%ssigned using : ", prefix ); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_x509_sig_alg_gets( p, n, &crl->sig_oid, crl->sig_pk, crl->sig_md, crl->sig_opts ); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_snprintf( p, n, "\n" ); MBEDTLS_X509_SAFE_SNPRINTF; return( (int) ( size - n ) ); } /* * Initialize a CRL chain */ void mbedtls_x509_crl_init( mbedtls_x509_crl *crl ) { memset( crl, 0, sizeof(mbedtls_x509_crl) ); } /* * Unallocate all CRL data */ void mbedtls_x509_crl_free( mbedtls_x509_crl *crl ) { mbedtls_x509_crl *crl_cur = crl; mbedtls_x509_crl *crl_prv; mbedtls_x509_name *name_cur; mbedtls_x509_name *name_prv; mbedtls_x509_crl_entry *entry_cur; mbedtls_x509_crl_entry *entry_prv; if( crl == NULL ) return; do { #if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT) mbedtls_free( crl_cur->sig_opts ); #endif name_cur = crl_cur->issuer.next; while( name_cur != NULL ) { name_prv = name_cur; name_cur = name_cur->next; mbedtls_platform_zeroize( name_prv, sizeof( mbedtls_x509_name ) ); mbedtls_free( name_prv ); } entry_cur = crl_cur->entry.next; while( entry_cur != NULL ) { entry_prv = entry_cur; entry_cur = entry_cur->next; mbedtls_platform_zeroize( entry_prv, sizeof( mbedtls_x509_crl_entry ) ); mbedtls_free( entry_prv ); } if( crl_cur->raw.p != NULL ) { mbedtls_platform_zeroize( crl_cur->raw.p, crl_cur->raw.len ); mbedtls_free( crl_cur->raw.p ); } crl_cur = crl_cur->next; } while( crl_cur != NULL ); crl_cur = crl; do { crl_prv = crl_cur; crl_cur = crl_cur->next; mbedtls_platform_zeroize( crl_prv, sizeof( mbedtls_x509_crl ) ); if( crl_prv != crl ) mbedtls_free( crl_prv ); } while( crl_cur != NULL ); } #endif /* MBEDTLS_X509_CRL_PARSE_C */