/* * X.509 certificate parsing and verification * * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved * 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. * * This file is part of mbed TLS (https://tls.mbed.org) */ /* * 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 * * [SIRO] https://cabforum.org/wp-content/uploads/Chunghwatelecom201503cabforumV4.pdf */ #if !defined(MBEDTLS_CONFIG_FILE) #include "mbedtls/config.h" #else #include MBEDTLS_CONFIG_FILE #endif #if defined(MBEDTLS_X509_CRT_PARSE_C) #include "mbedtls/x509_crt.h" #include "mbedtls/x509_internal.h" #include "mbedtls/oid.h" #include "mbedtls/platform_util.h" #include #if defined(MBEDTLS_PEM_PARSE_C) #include "mbedtls/pem.h" #endif #if defined(MBEDTLS_PLATFORM_C) #include "mbedtls/platform.h" #else #include #include #define mbedtls_free free #define mbedtls_calloc calloc #define mbedtls_snprintf snprintf #endif #if defined(MBEDTLS_THREADING_C) #include "mbedtls/threading.h" #endif #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32) #include #else #include #endif #if defined(MBEDTLS_FS_IO) #include #if !defined(_WIN32) || defined(EFIX64) || defined(EFI32) #include #include #include #endif /* !_WIN32 || EFIX64 || EFI32 */ #endif #if !defined(MBEDTLS_X509_ON_DEMAND_PARSING) static void x509_buf_to_buf_raw( mbedtls_x509_buf_raw *dst, mbedtls_x509_buf const *src ) { dst->p = src->p; dst->len = src->len; } static void x509_buf_raw_to_buf( mbedtls_x509_buf *dst, mbedtls_x509_buf_raw const *src ) { dst->p = src->p; dst->len = src->len; } #endif /* MBEDTLS_X509_ON_DEMAND_PARSING */ static int x509_crt_parse_frame( unsigned char *start, unsigned char *end, mbedtls_x509_crt_frame *frame ); static int x509_crt_subject_from_frame( mbedtls_x509_crt_frame const *frame, mbedtls_x509_name *subject ); static int x509_crt_issuer_from_frame( mbedtls_x509_crt_frame const *frame, mbedtls_x509_name *issuer ); static int x509_crt_subject_alt_from_frame( mbedtls_x509_crt_frame const *frame, mbedtls_x509_sequence *subject_alt ); static int x509_crt_ext_key_usage_from_frame( mbedtls_x509_crt_frame const *frame, mbedtls_x509_sequence *ext_key_usage ); int mbedtls_x509_crt_flush_cache_pk( mbedtls_x509_crt const *crt ) { #if defined(MBEDTLS_THREADING_C) if( mbedtls_mutex_lock( &crt->cache->pk_mutex ) != 0 ) return( MBEDTLS_ERR_THREADING_MUTEX_ERROR ); #endif #if !defined(MBEDTLS_X509_ALWAYS_FLUSH) || \ defined(MBEDTLS_THREADING_C) /* Can only free the PK context if nobody is using it. * If MBEDTLS_X509_ALWAYS_FLUSH is set, nested uses * of xxx_acquire() are prohibited, and no reference * counting is needed. Also, notice that the code-path * below is safe if the cache isn't filled. */ if( crt->cache->pk_readers == 0 ) #endif /* !MBEDTLS_X509_ALWAYS_FLUSH || MBEDTLS_THREADING_C */ { #if !defined(MBEDTLS_X509_ON_DEMAND_PARSING) /* The cache holds a shallow copy of the PK context * in the legacy struct, so don't free PK context. */ mbedtls_free( crt->cache->pk ); #else mbedtls_pk_free( crt->cache->pk ); mbedtls_free( crt->cache->pk ); #endif /* MBEDTLS_X509_ON_DEMAND_PARSING */ crt->cache->pk = NULL; } #if defined(MBEDTLS_THREADING_C) if( mbedtls_mutex_unlock( &crt->cache->pk_mutex ) != 0 ) return( MBEDTLS_ERR_THREADING_MUTEX_ERROR ); #endif return( 0 ); } int mbedtls_x509_crt_flush_cache_frame( mbedtls_x509_crt const *crt ) { #if defined(MBEDTLS_THREADING_C) if( mbedtls_mutex_lock( &crt->cache->frame_mutex ) != 0 ) return( MBEDTLS_ERR_THREADING_MUTEX_ERROR ); #endif #if !defined(MBEDTLS_X509_ALWAYS_FLUSH) || \ defined(MBEDTLS_THREADING_C) /* Can only free the PK context if nobody is using it. * If MBEDTLS_X509_ALWAYS_FLUSH is set, nested uses * of xxx_acquire() are prohibited, and no reference * counting is needed. Also, notice that the code-path * below is safe if the cache isn't filled. */ if( crt->cache->frame_readers == 0 ) #endif /* !MBEDTLS_X509_ALWAYS_FLUSH || MBEDTLS_THREADING_C */ { mbedtls_free( crt->cache->frame ); crt->cache->frame = NULL; } #if defined(MBEDTLS_THREADING_C) if( mbedtls_mutex_unlock( &crt->cache->frame_mutex ) != 0 ) return( MBEDTLS_ERR_THREADING_MUTEX_ERROR ); #endif return( 0 ); } int mbedtls_x509_crt_flush_cache( mbedtls_x509_crt const *crt ) { int ret; ret = mbedtls_x509_crt_flush_cache_frame( crt ); if( ret != 0 ) return( ret ); ret = mbedtls_x509_crt_flush_cache_pk( crt ); if( ret != 0 ) return( ret ); return( 0 ); } static int x509_crt_frame_parse_ext( mbedtls_x509_crt_frame *frame ); int mbedtls_x509_crt_cache_provide_frame( mbedtls_x509_crt const *crt ) { mbedtls_x509_crt_cache *cache = crt->cache; mbedtls_x509_crt_frame *frame; if( cache->frame != NULL ) { #if !defined(MBEDTLS_X509_ALWAYS_FLUSH) || \ defined(MBEDTLS_THREADING_C) return( 0 ); #else /* If MBEDTLS_X509_ALWAYS_FLUSH is set, we don't * allow nested uses of acquire. */ return( MBEDTLS_ERR_X509_FATAL_ERROR ); #endif } frame = mbedtls_calloc( 1, sizeof( mbedtls_x509_crt_frame ) ); if( frame == NULL ) return( MBEDTLS_ERR_X509_ALLOC_FAILED ); cache->frame = frame; #if defined(MBEDTLS_X509_ON_DEMAND_PARSING) /* This would work with !MBEDTLS_X509_ON_DEMAND_PARSING, too, * but is inefficient compared to copying the respective fields * from the legacy mbedtls_x509_crt. */ return( x509_crt_parse_frame( crt->raw.p, crt->raw.p + crt->raw.len, frame ) ); #else /* MBEDTLS_X509_ON_DEMAND_PARSING */ /* Make sure all extension related fields are properly initialized. */ frame->ca_istrue = 0; frame->max_pathlen = 0; frame->ext_types = 0; frame->version = crt->version; frame->sig_md = crt->sig_md; frame->sig_pk = crt->sig_pk; frame->valid_from = crt->valid_from; frame->valid_to = crt->valid_to; x509_buf_to_buf_raw( &frame->raw, &crt->raw ); x509_buf_to_buf_raw( &frame->tbs, &crt->tbs ); x509_buf_to_buf_raw( &frame->serial, &crt->serial ); x509_buf_to_buf_raw( &frame->pubkey_raw, &crt->pk_raw ); x509_buf_to_buf_raw( &frame->issuer_raw, &crt->issuer_raw ); x509_buf_to_buf_raw( &frame->subject_raw, &crt->subject_raw ); x509_buf_to_buf_raw( &frame->subject_id, &crt->subject_id ); x509_buf_to_buf_raw( &frame->issuer_id, &crt->issuer_id ); x509_buf_to_buf_raw( &frame->sig, &crt->sig ); x509_buf_to_buf_raw( &frame->v3_ext, &crt->v3_ext ); /* The legacy CRT structure doesn't explicitly contain * the `AlgorithmIdentifier` bounds; however, those can * be inferred from the surrounding (mandatory) `SerialNumber` * and `Issuer` fields. */ frame->sig_alg.p = crt->serial.p + crt->serial.len; frame->sig_alg.len = crt->issuer_raw.p - frame->sig_alg.p; return( x509_crt_frame_parse_ext( frame ) ); #endif /* !MBEDTLS_X509_ON_DEMAND_PARSING */ } int mbedtls_x509_crt_cache_provide_pk( mbedtls_x509_crt const *crt ) { mbedtls_x509_crt_cache *cache = crt->cache; mbedtls_pk_context *pk; if( cache->pk != NULL ) { #if !defined(MBEDTLS_X509_ALWAYS_FLUSH) || \ defined(MBEDTLS_THREADING_C) return( 0 ); #else /* If MBEDTLS_X509_ALWAYS_FLUSH is set, we don't * allow nested uses of acquire. */ return( MBEDTLS_ERR_X509_FATAL_ERROR ); #endif } pk = mbedtls_calloc( 1, sizeof( mbedtls_pk_context ) ); if( pk == NULL ) return( MBEDTLS_ERR_X509_ALLOC_FAILED ); cache->pk = pk; #if !defined(MBEDTLS_X509_ON_DEMAND_PARSING) *pk = crt->pk; return( 0 ); #else { mbedtls_x509_buf_raw pk_raw = cache->pk_raw; return( mbedtls_pk_parse_subpubkey( &pk_raw.p, pk_raw.p + pk_raw.len, pk ) ); } #endif /* MBEDTLS_X509_ON_DEMAND_PARSING */ } static void x509_crt_cache_init( mbedtls_x509_crt_cache *cache ) { memset( cache, 0, sizeof( *cache ) ); #if defined(MBEDTLS_THREADING_C) mbedtls_mutex_init( &cache->frame_mutex ); mbedtls_mutex_init( &cache->pk_mutex ); #endif } static void x509_crt_cache_clear_pk( mbedtls_x509_crt_cache *cache ) { #if !defined(MBEDTLS_X509_ON_DEMAND_PARSING) /* The cache holds a shallow copy of the PK context * in the legacy struct, so don't free PK context. */ mbedtls_free( cache->pk ); #else mbedtls_pk_free( cache->pk ); mbedtls_free( cache->pk ); #endif /* MBEDTLS_X509_ON_DEMAND_PARSING */ cache->pk = NULL; } static void x509_crt_cache_clear_frame( mbedtls_x509_crt_cache *cache ) { mbedtls_free( cache->frame ); cache->frame = NULL; } static void x509_crt_cache_free( mbedtls_x509_crt_cache *cache ) { if( cache == NULL ) return; #if defined(MBEDTLS_THREADING_C) mbedtls_mutex_free( &cache->frame_mutex ); mbedtls_mutex_free( &cache->pk_mutex ); #endif x509_crt_cache_clear_frame( cache ); x509_crt_cache_clear_pk( cache ); memset( cache, 0, sizeof( *cache ) ); } int mbedtls_x509_crt_get_subject_alt_names( mbedtls_x509_crt const *crt, mbedtls_x509_sequence **subj_alt ) { int ret; mbedtls_x509_crt_frame const *frame; mbedtls_x509_sequence *seq; ret = mbedtls_x509_crt_frame_acquire( crt, &frame ); if( ret != 0 ) return( ret ); seq = mbedtls_calloc( 1, sizeof( mbedtls_x509_sequence ) ); if( seq == NULL ) ret = MBEDTLS_ERR_X509_ALLOC_FAILED; else ret = x509_crt_subject_alt_from_frame( frame, seq ); mbedtls_x509_crt_frame_release( crt ); *subj_alt = seq; return( ret ); } int mbedtls_x509_crt_get_ext_key_usage( mbedtls_x509_crt const *crt, mbedtls_x509_sequence **ext_key_usage ) { int ret; mbedtls_x509_crt_frame const *frame; mbedtls_x509_sequence *seq; ret = mbedtls_x509_crt_frame_acquire( crt, &frame ); if( ret != 0 ) return( ret ); seq = mbedtls_calloc( 1, sizeof( mbedtls_x509_sequence ) ); if( seq == NULL ) ret = MBEDTLS_ERR_X509_ALLOC_FAILED; else ret = x509_crt_ext_key_usage_from_frame( frame, seq ); mbedtls_x509_crt_frame_release( crt ); *ext_key_usage = seq; return( ret ); } int mbedtls_x509_crt_get_subject( mbedtls_x509_crt const *crt, mbedtls_x509_name **subject ) { int ret; mbedtls_x509_crt_frame const *frame; mbedtls_x509_name *name; ret = mbedtls_x509_crt_frame_acquire( crt, &frame ); if( ret != 0 ) return( ret ); name = mbedtls_calloc( 1, sizeof( mbedtls_x509_name ) ); if( name == NULL ) ret = MBEDTLS_ERR_X509_ALLOC_FAILED; else ret = x509_crt_subject_from_frame( frame, name ); mbedtls_x509_crt_frame_release( crt ); *subject = name; return( ret ); } int mbedtls_x509_crt_get_issuer( mbedtls_x509_crt const *crt, mbedtls_x509_name **issuer ) { int ret; mbedtls_x509_crt_frame const *frame; mbedtls_x509_name *name; ret = mbedtls_x509_crt_frame_acquire( crt, &frame ); if( ret != 0 ) return( ret ); name = mbedtls_calloc( 1, sizeof( mbedtls_x509_name ) ); if( name == NULL ) ret = MBEDTLS_ERR_X509_ALLOC_FAILED; else ret = x509_crt_issuer_from_frame( frame, name ); mbedtls_x509_crt_frame_release( crt ); *issuer = name; return( ret ); } int mbedtls_x509_crt_get_frame( mbedtls_x509_crt const *crt, mbedtls_x509_crt_frame *dst ) { int ret; mbedtls_x509_crt_frame const *frame; ret = mbedtls_x509_crt_frame_acquire( crt, &frame ); if( ret != 0 ) return( ret ); *dst = *frame; mbedtls_x509_crt_frame_release( crt ); return( 0 ); } int mbedtls_x509_crt_get_pk( mbedtls_x509_crt const *crt, mbedtls_pk_context *dst ) { #if !defined(MBEDTLS_X509_ON_DEMAND_PARSING) mbedtls_x509_buf_raw pk_raw = crt->cache->pk_raw; return( mbedtls_pk_parse_subpubkey( &pk_raw.p, pk_raw.p + pk_raw.len, dst ) ); #else /* !MBEDTLS_X509_ON_DEMAND_PARSING */ int ret; mbedtls_pk_context *pk; ret = mbedtls_x509_crt_pk_acquire( crt, &pk ); if( ret != 0 ) return( ret ); /* Move PK from CRT cache to destination pointer * to avoid a copy. */ *dst = *pk; mbedtls_free( crt->cache->pk ); crt->cache->pk = NULL; mbedtls_x509_crt_pk_release( crt ); return( 0 ); #endif /* MBEDTLS_X509_ON_DEMAND_PARSING */ } /* * Item in a verification chain: cert and flags for it */ typedef struct { mbedtls_x509_crt *crt; uint32_t flags; } x509_crt_verify_chain_item; /* * Max size of verification chain: end-entity + intermediates + trusted root */ #define X509_MAX_VERIFY_CHAIN_SIZE ( MBEDTLS_X509_MAX_INTERMEDIATE_CA + 2 ) /* * Default profile */ const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_default = { #if defined(MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES) /* Allow SHA-1 (weak, but still safe in controlled environments) */ MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA1 ) | #endif /* Only SHA-2 hashes */ MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA224 ) | MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA256 ) | MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA384 ) | MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA512 ), 0xFFFFFFF, /* Any PK alg */ 0xFFFFFFF, /* Any curve */ 2048, }; /* * Next-default profile */ const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_next = { /* Hashes from SHA-256 and above */ MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA256 ) | MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA384 ) | MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA512 ), 0xFFFFFFF, /* Any PK alg */ #if defined(MBEDTLS_ECP_C) /* Curves at or above 128-bit security level */ MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP256R1 ) | MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP384R1 ) | MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP521R1 ) | MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_BP256R1 ) | MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_BP384R1 ) | MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_BP512R1 ) | MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP256K1 ), #else 0, #endif 2048, }; /* * NSA Suite B Profile */ const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_suiteb = { /* Only SHA-256 and 384 */ MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA256 ) | MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA384 ), /* Only ECDSA */ MBEDTLS_X509_ID_FLAG( MBEDTLS_PK_ECDSA ) | MBEDTLS_X509_ID_FLAG( MBEDTLS_PK_ECKEY ), #if defined(MBEDTLS_ECP_C) /* Only NIST P-256 and P-384 */ MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP256R1 ) | MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP384R1 ), #else 0, #endif 0, }; /* * Check md_alg against profile * Return 0 if md_alg is acceptable for this profile, -1 otherwise */ static int x509_profile_check_md_alg( const mbedtls_x509_crt_profile *profile, mbedtls_md_type_t md_alg ) { if( md_alg == MBEDTLS_MD_NONE ) return( -1 ); if( ( profile->allowed_mds & MBEDTLS_X509_ID_FLAG( md_alg ) ) != 0 ) return( 0 ); return( -1 ); } /* * Check pk_alg against profile * Return 0 if pk_alg is acceptable for this profile, -1 otherwise */ static int x509_profile_check_pk_alg( const mbedtls_x509_crt_profile *profile, mbedtls_pk_type_t pk_alg ) { if( pk_alg == MBEDTLS_PK_NONE ) return( -1 ); if( ( profile->allowed_pks & MBEDTLS_X509_ID_FLAG( pk_alg ) ) != 0 ) return( 0 ); return( -1 ); } /* * Check key against profile * Return 0 if pk is acceptable for this profile, -1 otherwise */ static int x509_profile_check_key( const mbedtls_x509_crt_profile *profile, const mbedtls_pk_context *pk ) { const mbedtls_pk_type_t pk_alg = mbedtls_pk_get_type( pk ); #if defined(MBEDTLS_RSA_C) if( pk_alg == MBEDTLS_PK_RSA || pk_alg == MBEDTLS_PK_RSASSA_PSS ) { if( mbedtls_pk_get_bitlen( pk ) >= profile->rsa_min_bitlen ) return( 0 ); return( -1 ); } #endif #if defined(MBEDTLS_ECP_C) if( pk_alg == MBEDTLS_PK_ECDSA || pk_alg == MBEDTLS_PK_ECKEY || pk_alg == MBEDTLS_PK_ECKEY_DH ) { const mbedtls_ecp_group_id gid = mbedtls_pk_ec( *pk )->grp.id; if( gid == MBEDTLS_ECP_DP_NONE ) return( -1 ); if( ( profile->allowed_curves & MBEDTLS_X509_ID_FLAG( gid ) ) != 0 ) return( 0 ); return( -1 ); } #endif return( -1 ); } /* * Return 0 if name matches wildcard, -1 otherwise */ static int x509_check_wildcard( char const *cn, size_t cn_len, unsigned char const *buf, size_t buf_len ) { size_t i; size_t cn_idx = 0; /* We can't have a match if there is no wildcard to match */ if( buf_len < 3 || buf[0] != '*' || buf[1] != '.' ) return( -1 ); for( i = 0; i < cn_len; ++i ) { if( cn[i] == '.' ) { cn_idx = i; break; } } if( cn_idx == 0 ) return( -1 ); if( mbedtls_x509_memcasecmp( buf + 1, cn + cn_idx, buf_len - 1, cn_len - cn_idx ) == 0 ) { return( 0 ); } return( -1 ); } /* * Reset (init or clear) a verify_chain */ static void x509_crt_verify_chain_reset( mbedtls_x509_crt_verify_chain *ver_chain ) { size_t i; for( i = 0; i < MBEDTLS_X509_MAX_VERIFY_CHAIN_SIZE; i++ ) { ver_chain->items[i].crt = NULL; ver_chain->items[i].flags = (uint32_t) -1; } ver_chain->len = 0; } /* * Version ::= INTEGER { v1(0), v2(1), v3(2) } */ static int x509_get_version( unsigned char **p, const unsigned char *end, int *ver ) { int ret; size_t len; if( ( ret = mbedtls_asn1_get_tag( p, end, &len, MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 0 ) ) != 0 ) { if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) { *ver = 0; return( 0 ); } return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret ); } end = *p + len; if( ( ret = mbedtls_asn1_get_int( p, end, ver ) ) != 0 ) return( MBEDTLS_ERR_X509_INVALID_VERSION + ret ); if( *p != end ) return( MBEDTLS_ERR_X509_INVALID_VERSION + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ); return( 0 ); } /* * Validity ::= SEQUENCE { * notBefore Time, * notAfter Time } */ static int x509_get_dates( unsigned char **p, const unsigned char *end, mbedtls_x509_time *from, mbedtls_x509_time *to ) { int ret; size_t len; if( ( ret = mbedtls_asn1_get_tag( p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) return( MBEDTLS_ERR_X509_INVALID_DATE + ret ); end = *p + len; if( ( ret = mbedtls_x509_get_time( p, end, from ) ) != 0 ) return( ret ); if( ( ret = mbedtls_x509_get_time( p, end, to ) ) != 0 ) return( ret ); if( *p != end ) return( MBEDTLS_ERR_X509_INVALID_DATE + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ); return( 0 ); } /* * X.509 v2/v3 unique identifier (not parsed) */ static int x509_get_uid( unsigned char **p, const unsigned char *end, mbedtls_x509_buf_raw *uid, int n ) { int ret; if( *p == end ) return( 0 ); if( ( ret = mbedtls_asn1_get_tag( p, end, &uid->len, MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | n ) ) != 0 ) { if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) return( 0 ); return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret ); } uid->p = *p; *p += uid->len; return( 0 ); } static int x509_get_basic_constraints( unsigned char **p, const unsigned char *end, int *ca_istrue, int *max_pathlen ) { int ret; size_t len; /* * BasicConstraints ::= SEQUENCE { * cA BOOLEAN DEFAULT FALSE, * pathLenConstraint INTEGER (0..MAX) OPTIONAL } */ *ca_istrue = 0; /* DEFAULT FALSE */ *max_pathlen = 0; /* endless */ if( ( ret = mbedtls_asn1_get_tag( p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) return( ret ); if( *p == end ) return( 0 ); if( ( ret = mbedtls_asn1_get_bool( p, end, ca_istrue ) ) != 0 ) { if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) ret = mbedtls_asn1_get_int( p, end, ca_istrue ); if( ret != 0 ) return( ret ); if( *ca_istrue != 0 ) *ca_istrue = 1; } if( *p == end ) return( 0 ); if( ( ret = mbedtls_asn1_get_int( p, end, max_pathlen ) ) != 0 ) return( ret ); if( *p != end ) return( MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ); (*max_pathlen)++; return( 0 ); } static int x509_get_ns_cert_type( unsigned char **p, const unsigned char *end, unsigned char *ns_cert_type) { int ret; mbedtls_x509_bitstring bs = { 0, 0, NULL }; if( ( ret = mbedtls_asn1_get_bitstring( p, end, &bs ) ) != 0 ) return( ret ); if( bs.len != 1 ) return( MBEDTLS_ERR_ASN1_INVALID_LENGTH ); /* Get actual bitstring */ *ns_cert_type = *bs.p; return( 0 ); } static int x509_get_key_usage( unsigned char **p, const unsigned char *end, uint16_t *key_usage) { int ret; size_t i; mbedtls_x509_bitstring bs = { 0, 0, NULL }; if( ( ret = mbedtls_asn1_get_bitstring( p, end, &bs ) ) != 0 ) return( ret ); if( bs.len < 1 ) return( MBEDTLS_ERR_ASN1_INVALID_LENGTH ); /* Get actual bitstring */ *key_usage = 0; for( i = 0; i < bs.len && i < sizeof( *key_usage ); i++ ) { *key_usage |= (uint16_t) bs.p[i] << ( 8*i ); } return( 0 ); } static int asn1_build_sequence_cb( void *ctx, int tag, unsigned char *data, size_t data_len ) { mbedtls_asn1_sequence **cur_ptr = (mbedtls_asn1_sequence **) ctx; mbedtls_asn1_sequence *cur = *cur_ptr; /* Allocate and assign next pointer */ if( cur->buf.p != NULL ) { cur->next = mbedtls_calloc( 1, sizeof( mbedtls_asn1_sequence ) ); if( cur->next == NULL ) return( MBEDTLS_ERR_ASN1_ALLOC_FAILED ); cur = cur->next; } cur->buf.tag = tag; cur->buf.p = data; cur->buf.len = data_len; *cur_ptr = cur; return( 0 ); } /* * ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId * * KeyPurposeId ::= OBJECT IDENTIFIER */ static int x509_get_ext_key_usage( unsigned char **p, const unsigned char *end, mbedtls_x509_sequence *ext_key_usage) { return( mbedtls_asn1_traverse_sequence_of( p, end, 0xFF, MBEDTLS_ASN1_OID, 0, 0, asn1_build_sequence_cb, (void *) &ext_key_usage ) ); } /* * SubjectAltName ::= GeneralNames * * GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName * * GeneralName ::= CHOICE { * otherName [0] OtherName, * rfc822Name [1] IA5String, * dNSName [2] IA5String, * x400Address [3] ORAddress, * directoryName [4] Name, * ediPartyName [5] EDIPartyName, * uniformResourceIdentifier [6] IA5String, * iPAddress [7] OCTET STRING, * registeredID [8] OBJECT IDENTIFIER } * * OtherName ::= SEQUENCE { * type-id OBJECT IDENTIFIER, * value [0] EXPLICIT ANY DEFINED BY type-id } * * EDIPartyName ::= SEQUENCE { * nameAssigner [0] DirectoryString OPTIONAL, * partyName [1] DirectoryString } * * NOTE: we only parse and use dNSName at this point. */ static int x509_get_subject_alt_name( unsigned char *p, const unsigned char *end, mbedtls_x509_sequence *subject_alt_name ) { return( mbedtls_asn1_traverse_sequence_of( &p, end, MBEDTLS_ASN1_TAG_CLASS_MASK, MBEDTLS_ASN1_CONTEXT_SPECIFIC, MBEDTLS_ASN1_TAG_VALUE_MASK, 2 /* SubjectAlt DNS */, asn1_build_sequence_cb, (void *) &subject_alt_name ) ); } /* * X.509 v3 extensions * */ static int x509_crt_get_ext_cb( void *ctx, int tag, unsigned char *p, size_t ext_len ) { int ret; mbedtls_x509_crt_frame *frame = (mbedtls_x509_crt_frame *) ctx; size_t len; unsigned char *end, *end_ext_octet; mbedtls_x509_buf extn_oid = { 0, 0, NULL }; int is_critical = 0; /* DEFAULT FALSE */ int ext_type = 0; ((void) tag); /* * Extension ::= SEQUENCE { * extnID OBJECT IDENTIFIER, * critical BOOLEAN DEFAULT FALSE, * extnValue OCTET STRING } */ end = p + ext_len; /* Get extension ID */ if( ( ret = mbedtls_asn1_get_tag( &p, end, &extn_oid.len, MBEDTLS_ASN1_OID ) ) != 0 ) goto err; extn_oid.tag = MBEDTLS_ASN1_OID; extn_oid.p = p; p += extn_oid.len; /* Get optional critical */ if( ( ret = mbedtls_asn1_get_bool( &p, end, &is_critical ) ) != 0 && ( ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) ) goto err; /* Data should be octet string type */ if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 ) goto err; end_ext_octet = p + len; if( end_ext_octet != end ) { ret = MBEDTLS_ERR_ASN1_LENGTH_MISMATCH; goto err; } /* * Detect supported extensions */ ret = mbedtls_oid_get_x509_ext_type( &extn_oid, &ext_type ); if( ret != 0 ) { #if !defined(MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION) if( is_critical ) { /* Data is marked as critical: fail */ ret = MBEDTLS_ERR_ASN1_UNEXPECTED_TAG; goto err; } #endif /* MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION */ return( 0 ); } /* Forbid repeated extensions */ if( ( frame->ext_types & ext_type ) != 0 ) return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS ); frame->ext_types |= ext_type; switch( ext_type ) { case MBEDTLS_X509_EXT_BASIC_CONSTRAINTS: { int ca_istrue; int max_pathlen; /* Parse basic constraints */ ret = x509_get_basic_constraints( &p, end_ext_octet, &ca_istrue, &max_pathlen ); if( ret != 0 ) goto err; frame->ca_istrue = ca_istrue; frame->max_pathlen = max_pathlen; break; } case MBEDTLS_X509_EXT_KEY_USAGE: /* Parse key usage */ ret = x509_get_key_usage( &p, end_ext_octet, &frame->key_usage ); if( ret != 0 ) goto err; break; case MBEDTLS_X509_EXT_SUBJECT_ALT_NAME: /* Copy reference to raw subject alt name data. */ frame->subject_alt_raw.p = p; frame->subject_alt_raw.len = end_ext_octet - p; ret = mbedtls_asn1_traverse_sequence_of( &p, end_ext_octet, MBEDTLS_ASN1_TAG_CLASS_MASK, MBEDTLS_ASN1_CONTEXT_SPECIFIC, MBEDTLS_ASN1_TAG_VALUE_MASK, 2 /* SubjectAlt DNS */, NULL, NULL ); if( ret != 0 ) goto err; break; case MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE: /* Parse extended key usage */ frame->ext_key_usage_raw.p = p; frame->ext_key_usage_raw.len = end_ext_octet - p; if( frame->ext_key_usage_raw.len == 0 ) { ret = MBEDTLS_ERR_ASN1_INVALID_LENGTH; goto err; } /* Check structural sanity of extension. */ ret = mbedtls_asn1_traverse_sequence_of( &p, end_ext_octet, 0xFF, MBEDTLS_ASN1_OID, 0, 0, NULL, NULL ); if( ret != 0 ) goto err; break; case MBEDTLS_X509_EXT_NS_CERT_TYPE: /* Parse netscape certificate type */ ret = x509_get_ns_cert_type( &p, end_ext_octet, &frame->ns_cert_type ); if( ret != 0 ) goto err; break; default: /* * If this is a non-critical extension, which the oid layer * supports, but there isn't an X.509 parser for it, * skip the extension. */ #if !defined(MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION) if( is_critical ) return( MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE ); #endif p = end_ext_octet; } return( 0 ); err: return( ret ); } static int x509_crt_frame_parse_ext( mbedtls_x509_crt_frame *frame ) { int ret; unsigned char *p = frame->v3_ext.p; unsigned char *end = p + frame->v3_ext.len; if( p == end ) return( 0 ); ret = mbedtls_asn1_traverse_sequence_of( &p, end, 0xFF, MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED, 0, 0, x509_crt_get_ext_cb, frame ); if( ret == MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE ) return( ret ); if( ret == MBEDTLS_ERR_X509_INVALID_EXTENSIONS ) return( ret ); if( ret != 0 ) ret += MBEDTLS_ERR_X509_INVALID_EXTENSIONS; return( ret ); } static int x509_crt_parse_frame( unsigned char *start, unsigned char *end, mbedtls_x509_crt_frame *frame ) { int ret; unsigned char *p; size_t len; mbedtls_x509_buf tmp; unsigned char *tbs_start; mbedtls_x509_buf outer_sig_alg; size_t inner_sig_alg_len; unsigned char *inner_sig_alg_start; memset( frame, 0, sizeof( *frame ) ); /* * Certificate ::= SEQUENCE { * tbsCertificate TBSCertificate, * signatureAlgorithm AlgorithmIdentifier, * signatureValue BIT STRING * } * */ p = start; frame->raw.p = p; if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) { return( MBEDTLS_ERR_X509_INVALID_FORMAT ); } /* NOTE: We are currently not checking that the `Certificate` * structure spans the entire buffer. */ end = p + len; frame->raw.len = end - frame->raw.p; /* * TBSCertificate ::= SEQUENCE { ... */ frame->tbs.p = p; if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) { return( ret + MBEDTLS_ERR_X509_INVALID_FORMAT ); } tbs_start = p; /* Breadth-first parsing: Jump over TBS for now. */ p += len; frame->tbs.len = p - frame->tbs.p; /* * AlgorithmIdentifier ::= SEQUENCE { ... */ outer_sig_alg.p = p; if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) { return( MBEDTLS_ERR_X509_INVALID_ALG + ret ); } p += len; outer_sig_alg.len = p - outer_sig_alg.p; /* * signatureValue BIT STRING */ ret = mbedtls_x509_get_sig( &p, end, &tmp ); if( ret != 0 ) return( ret ); frame->sig.p = tmp.p; frame->sig.len = tmp.len; /* Check that we consumed the entire `Certificate` structure. */ if( p != end ) { return( MBEDTLS_ERR_X509_INVALID_FORMAT + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ); } /* Parse TBSCertificate structure * * TBSCertificate ::= SEQUENCE { * version [0] EXPLICIT Version DEFAULT v1, * serialNumber CertificateSerialNumber, * signature AlgorithmIdentifier, * issuer Name, * validity Validity, * subject Name, * subjectPublicKeyInfo SubjectPublicKeyInfo, * issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL, * -- If present, version MUST be v2 or v3 * subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL, * -- If present, version MUST be v2 or v3 * extensions [3] EXPLICIT Extensions OPTIONAL * -- If present, version MUST be v3 * } */ end = frame->tbs.p + frame->tbs.len; p = tbs_start; /* * Version ::= INTEGER { v1(0), v2(1), v3(2) } */ { int version; ret = x509_get_version( &p, end, &version ); if( ret != 0 ) return( ret ); if( version < 0 || version > 2 ) return( MBEDTLS_ERR_X509_UNKNOWN_VERSION ); frame->version = version + 1; } /* * CertificateSerialNumber ::= INTEGER */ ret = mbedtls_x509_get_serial( &p, end, &tmp ); if( ret != 0 ) return( ret ); frame->serial.p = tmp.p; frame->serial.len = tmp.len; /* * signature AlgorithmIdentifier */ inner_sig_alg_start = p; ret = mbedtls_x509_get_sig_alg_raw( &p, end, &frame->sig_md, &frame->sig_pk, NULL ); if( ret != 0 ) return( ret ); inner_sig_alg_len = p - inner_sig_alg_start; frame->sig_alg.p = inner_sig_alg_start; frame->sig_alg.len = inner_sig_alg_len; /* Consistency check: * Inner and outer AlgorithmIdentifier structures must coincide: * * Quoting RFC 5280, Section 4.1.1.2: * This field MUST contain the same algorithm identifier as the * signature field in the sequence tbsCertificate (Section 4.1.2.3). */ if( outer_sig_alg.len != inner_sig_alg_len || memcmp( outer_sig_alg.p, inner_sig_alg_start, inner_sig_alg_len ) != 0 ) { return( MBEDTLS_ERR_X509_SIG_MISMATCH ); } /* * issuer Name * * Name ::= CHOICE { -- only one possibility for now -- * rdnSequence RDNSequence } * * RDNSequence ::= SEQUENCE OF RelativeDistinguishedName */ frame->issuer_raw.p = p; ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ); if( ret != 0 ) return( ret + MBEDTLS_ERR_X509_INVALID_FORMAT ); p += len; frame->issuer_raw.len = p - frame->issuer_raw.p; /* Comparing the raw buffer to itself amounts to structural validation. */ ret = mbedtls_x509_name_cmp_raw( &frame->issuer_raw, &frame->issuer_raw, NULL, NULL ); if( ret != 0 ) return( ret ); /* * Validity ::= SEQUENCE { ... */ ret = x509_get_dates( &p, end, &frame->valid_from, &frame->valid_to ); if( ret != 0 ) return( ret ); /* * subject Name * * Name ::= CHOICE { -- only one possibility for now -- * rdnSequence RDNSequence } * * RDNSequence ::= SEQUENCE OF RelativeDistinguishedName */ frame->subject_raw.p = p; ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ); if( ret != 0 ) return( ret + MBEDTLS_ERR_X509_INVALID_FORMAT ); p += len; frame->subject_raw.len = p - frame->subject_raw.p; /* Comparing the raw buffer to itself amounts to structural validation. */ ret = mbedtls_x509_name_cmp_raw( &frame->subject_raw, &frame->subject_raw, NULL, NULL ); if( ret != 0 ) return( ret ); /* * SubjectPublicKeyInfo */ frame->pubkey_raw.p = p; ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ); if( ret != 0 ) return( ret + MBEDTLS_ERR_PK_KEY_INVALID_FORMAT ); p += len; frame->pubkey_raw.len = p - frame->pubkey_raw.p; if( frame->version != 1 ) { /* * issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL, * -- If present, version shall be v2 or v3 */ ret = x509_get_uid( &p, end, &frame->issuer_id, 1 /* implicit tag */ ); if( ret != 0 ) return( ret ); /* * subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL, * -- If present, version shall be v2 or v3 */ ret = x509_get_uid( &p, end, &frame->subject_id, 2 /* implicit tag */ ); if( ret != 0 ) return( ret ); } /* * extensions [3] EXPLICIT Extensions OPTIONAL * -- If present, version shall be v3 */ #if !defined(MBEDTLS_X509_ALLOW_EXTENSIONS_NON_V3) if( frame->version == 3 ) #endif { if( p != end ) { ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 3 ); if( len == 0 ) ret = MBEDTLS_ERR_ASN1_OUT_OF_DATA; if( ret != 0 ) return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret ); frame->v3_ext.p = p; frame->v3_ext.len = len; p += len; } ret = x509_crt_frame_parse_ext( frame ); if( ret != 0 ) return( ret ); } /* Wrapup: Check that we consumed the entire `TBSCertificate` structure. */ if( p != end ) { return( MBEDTLS_ERR_X509_INVALID_FORMAT + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ); } return( 0 ); } static int x509_crt_subject_from_frame( mbedtls_x509_crt_frame const *frame, mbedtls_x509_name *subject ) { return( mbedtls_x509_get_name( frame->subject_raw.p, frame->subject_raw.len, subject ) ); } static int x509_crt_issuer_from_frame( mbedtls_x509_crt_frame const *frame, mbedtls_x509_name *issuer ) { return( mbedtls_x509_get_name( frame->issuer_raw.p, frame->issuer_raw.len, issuer ) ); } static int x509_crt_subject_alt_from_frame( mbedtls_x509_crt_frame const *frame, mbedtls_x509_sequence *subject_alt ) { int ret; unsigned char *p = frame->subject_alt_raw.p; unsigned char *end = p + frame->subject_alt_raw.len; memset( subject_alt, 0, sizeof( *subject_alt ) ); if( ( frame->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME ) == 0 ) return( 0 ); ret = x509_get_subject_alt_name( p, end, subject_alt ); if( ret != 0 ) ret += MBEDTLS_ERR_X509_INVALID_EXTENSIONS; return( ret ); } static int x509_crt_ext_key_usage_from_frame( mbedtls_x509_crt_frame const *frame, mbedtls_x509_sequence *ext_key_usage ) { int ret; unsigned char *p = frame->ext_key_usage_raw.p; unsigned char *end = p + frame->ext_key_usage_raw.len; memset( ext_key_usage, 0, sizeof( *ext_key_usage ) ); if( ( frame->ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE ) == 0 ) return( 0 ); ret = x509_get_ext_key_usage( &p, end, ext_key_usage ); if( ret != 0 ) { ret += MBEDTLS_ERR_X509_INVALID_EXTENSIONS; return( ret ); } return( 0 ); } #if !defined(MBEDTLS_X509_ON_DEMAND_PARSING) static int x509_crt_pk_from_frame( mbedtls_x509_crt_frame *frame, mbedtls_pk_context *pk ) { unsigned char *p = frame->pubkey_raw.p; unsigned char *end = p + frame->pubkey_raw.len; return( mbedtls_pk_parse_subpubkey( &p, end, pk ) ); } #endif /* !MBEDTLS_X509_ON_DEMAND_PARSING */ /* * Parse and fill a single X.509 certificate in DER format */ static int x509_crt_parse_der_core( mbedtls_x509_crt *crt, const unsigned char *buf, size_t buflen, int make_copy ) { int ret; mbedtls_x509_crt_frame *frame; mbedtls_x509_crt_cache *cache; if( crt == NULL || buf == NULL ) return( MBEDTLS_ERR_X509_BAD_INPUT_DATA ); if( make_copy == 0 ) { crt->raw.p = (unsigned char*) buf; crt->raw.len = buflen; crt->own_buffer = 0; } else { /* Call mbedtls_calloc with buflen + 1 in order to avoid potential * return of NULL in case of length 0 certificates, which we want * to cleanly fail with MBEDTLS_ERR_X509_INVALID_FORMAT in the * core parsing routine, but not here. */ crt->raw.p = mbedtls_calloc( 1, buflen + 1 ); if( crt->raw.p == NULL ) return( MBEDTLS_ERR_X509_ALLOC_FAILED ); crt->raw.len = buflen; memcpy( crt->raw.p, buf, buflen ); crt->own_buffer = 1; } cache = mbedtls_calloc( 1, sizeof( mbedtls_x509_crt_cache ) ); if( cache == NULL ) { ret = MBEDTLS_ERR_X509_ALLOC_FAILED; goto exit; } crt->cache = cache; x509_crt_cache_init( cache ); #if defined(MBEDTLS_X509_ON_DEMAND_PARSING) ret = mbedtls_x509_crt_cache_provide_frame( crt ); if( ret != 0 ) goto exit; frame = crt->cache->frame; #else /* MBEDTLS_X509_ON_DEMAND_PARSING */ frame = mbedtls_calloc( 1, sizeof( mbedtls_x509_crt_frame ) ); if( frame == NULL ) { ret = MBEDTLS_ERR_X509_ALLOC_FAILED; goto exit; } cache->frame = frame; ret = x509_crt_parse_frame( crt->raw.p, crt->raw.p + crt->raw.len, frame ); if( ret != 0 ) goto exit; /* Copy frame to legacy CRT structure -- that's inefficient, but if * memory matters, the new CRT structure should be used anyway. */ x509_buf_raw_to_buf( &crt->tbs, &frame->tbs ); x509_buf_raw_to_buf( &crt->serial, &frame->serial ); x509_buf_raw_to_buf( &crt->issuer_raw, &frame->issuer_raw ); x509_buf_raw_to_buf( &crt->subject_raw, &frame->subject_raw ); x509_buf_raw_to_buf( &crt->issuer_id, &frame->issuer_id ); x509_buf_raw_to_buf( &crt->subject_id, &frame->subject_id ); x509_buf_raw_to_buf( &crt->pk_raw, &frame->pubkey_raw ); x509_buf_raw_to_buf( &crt->sig, &frame->sig ); x509_buf_raw_to_buf( &crt->v3_ext, &frame->v3_ext ); crt->valid_from = frame->valid_from; crt->valid_to = frame->valid_to; crt->version = frame->version; crt->ca_istrue = frame->ca_istrue; crt->max_pathlen = frame->max_pathlen; crt->ext_types = frame->ext_types; crt->key_usage = frame->key_usage; crt->ns_cert_type = frame->ns_cert_type; /* * Obtain the remaining fields from the frame. */ { /* sig_oid: Previously, needed for convenience in * mbedtls_x509_crt_info(), now pure legacy burden. */ unsigned char *tmp = frame->sig_alg.p; unsigned char *end = tmp + frame->sig_alg.len; mbedtls_x509_buf sig_oid, sig_params; ret = mbedtls_x509_get_alg( &tmp, end, &sig_oid, &sig_params ); if( ret != 0 ) { /* This should never happen, because we check * the sanity of the AlgorithmIdentifier structure * during frame parsing. */ ret = MBEDTLS_ERR_X509_FATAL_ERROR; goto exit; } crt->sig_oid = sig_oid; /* Signature parameters */ tmp = frame->sig_alg.p; ret = mbedtls_x509_get_sig_alg_raw( &tmp, end, &crt->sig_md, &crt->sig_pk, &crt->sig_opts ); if( ret != 0 ) { /* Again, this should never happen. */ ret = MBEDTLS_ERR_X509_FATAL_ERROR; goto exit; } } ret = x509_crt_pk_from_frame( frame, &crt->pk ); if( ret != 0 ) goto exit; ret = x509_crt_subject_from_frame( frame, &crt->subject ); if( ret != 0 ) goto exit; ret = x509_crt_issuer_from_frame( frame, &crt->issuer ); if( ret != 0 ) goto exit; ret = x509_crt_subject_alt_from_frame( frame, &crt->subject_alt_names ); if( ret != 0 ) goto exit; ret = x509_crt_ext_key_usage_from_frame( frame, &crt->ext_key_usage ); if( ret != 0 ) goto exit; #endif /* !MBEDTLS_X509_ON_DEMAND_PARSING */ /* Currently, we accept DER encoded CRTs with trailing garbage * and promise to not account for the garbage in the `raw` field. * * Note that this means that `crt->raw.len` is not necessarily the * full size of the heap buffer allocated at `crt->raw.p` in case * of copy-mode, but this is not a problem: freeing the buffer doesn't * need the size, and the garbage data doesn't need zeroization. */ crt->raw.len = frame->raw.len; cache->pk_raw = frame->pubkey_raw; /* Free the frame before parsing the public key to * keep peak RAM usage low. This is slightly inefficient * because the frame will need to be parsed again on the * first usage of the CRT, but that seems acceptable. * As soon as the frame gets used multiple times, it * will be cached by default. */ x509_crt_cache_clear_frame( crt->cache ); /* The cache just references the PK structure from the legacy * implementation, so set up the latter first before setting up * the cache. * * We're not actually using the parsed PK context here; * we just parse it to check that it's well-formed. */ ret = mbedtls_x509_crt_cache_provide_pk( crt ); if( ret != 0 ) goto exit; x509_crt_cache_clear_pk( crt->cache ); exit: if( ret != 0 ) mbedtls_x509_crt_free( crt ); return( ret ); } /* * Parse one X.509 certificate in DER format from a buffer and add them to a * chained list */ static int mbedtls_x509_crt_parse_der_internal( mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen, int make_copy ) { int ret; mbedtls_x509_crt *crt = chain, *prev = NULL; /* * Check for valid input */ if( crt == NULL || buf == NULL ) return( MBEDTLS_ERR_X509_BAD_INPUT_DATA ); while( crt->raw.p != NULL && crt->next != NULL ) { prev = crt; crt = crt->next; } /* * Add new certificate on the end of the chain if needed. */ if( crt->raw.p != NULL && crt->next == NULL ) { crt->next = mbedtls_calloc( 1, sizeof( mbedtls_x509_crt ) ); if( crt->next == NULL ) return( MBEDTLS_ERR_X509_ALLOC_FAILED ); prev = crt; mbedtls_x509_crt_init( crt->next ); crt = crt->next; } if( ( ret = x509_crt_parse_der_core( crt, buf, buflen, make_copy ) ) != 0 ) { if( prev ) prev->next = NULL; if( crt != chain ) mbedtls_free( crt ); return( ret ); } return( 0 ); } int mbedtls_x509_crt_parse_der_nocopy( mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen ) { return( mbedtls_x509_crt_parse_der_internal( chain, buf, buflen, 0 ) ); } int mbedtls_x509_crt_parse_der( mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen ) { return( mbedtls_x509_crt_parse_der_internal( chain, buf, buflen, 1 ) ); } /* * Parse one or more PEM certificates from a buffer and add them to the chained * list */ int mbedtls_x509_crt_parse( mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen ) { #if defined(MBEDTLS_PEM_PARSE_C) int success = 0, first_error = 0, total_failed = 0; int buf_format = MBEDTLS_X509_FORMAT_DER; #endif /* * Check for valid input */ if( chain == NULL || buf == NULL ) return( MBEDTLS_ERR_X509_BAD_INPUT_DATA ); /* * Determine buffer content. Buffer contains either one DER certificate or * one or more PEM certificates. */ #if defined(MBEDTLS_PEM_PARSE_C) if( buflen != 0 && buf[buflen - 1] == '\0' && strstr( (const char *) buf, "-----BEGIN CERTIFICATE-----" ) != NULL ) { buf_format = MBEDTLS_X509_FORMAT_PEM; } if( buf_format == MBEDTLS_X509_FORMAT_DER ) return mbedtls_x509_crt_parse_der( chain, buf, buflen ); #else return mbedtls_x509_crt_parse_der( chain, buf, buflen ); #endif #if defined(MBEDTLS_PEM_PARSE_C) if( buf_format == MBEDTLS_X509_FORMAT_PEM ) { int ret; mbedtls_pem_context pem; /* 1 rather than 0 since the terminating NULL byte is counted in */ while( buflen > 1 ) { size_t use_len; mbedtls_pem_init( &pem ); /* If we get there, we know the string is null-terminated */ ret = mbedtls_pem_read_buffer( &pem, "-----BEGIN CERTIFICATE-----", "-----END CERTIFICATE-----", buf, NULL, 0, &use_len ); if( ret == 0 ) { /* * Was PEM encoded */ buflen -= use_len; buf += use_len; } else if( ret == MBEDTLS_ERR_PEM_BAD_INPUT_DATA ) { return( ret ); } else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT ) { mbedtls_pem_free( &pem ); /* * PEM header and footer were found */ buflen -= use_len; buf += use_len; if( first_error == 0 ) first_error = ret; total_failed++; continue; } else break; ret = mbedtls_x509_crt_parse_der( chain, pem.buf, pem.buflen ); mbedtls_pem_free( &pem ); if( ret != 0 ) { /* * Quit parsing on a memory error */ if( ret == MBEDTLS_ERR_X509_ALLOC_FAILED ) return( ret ); if( first_error == 0 ) first_error = ret; total_failed++; continue; } success = 1; } } if( success ) return( total_failed ); else if( first_error ) return( first_error ); else return( MBEDTLS_ERR_X509_CERT_UNKNOWN_FORMAT ); #endif /* MBEDTLS_PEM_PARSE_C */ } #if defined(MBEDTLS_FS_IO) /* * Load one or more certificates and add them to the chained list */ int mbedtls_x509_crt_parse_file( mbedtls_x509_crt *chain, const char *path ) { int ret; size_t n; unsigned char *buf; if( ( ret = mbedtls_pk_load_file( path, &buf, &n ) ) != 0 ) return( ret ); ret = mbedtls_x509_crt_parse( chain, buf, n ); mbedtls_platform_zeroize( buf, n ); mbedtls_free( buf ); return( ret ); } int mbedtls_x509_crt_parse_path( mbedtls_x509_crt *chain, const char *path ) { int ret = 0; #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32) int w_ret; WCHAR szDir[MAX_PATH]; char filename[MAX_PATH]; char *p; size_t len = strlen( path ); WIN32_FIND_DATAW file_data; HANDLE hFind; if( len > MAX_PATH - 3 ) return( MBEDTLS_ERR_X509_BAD_INPUT_DATA ); memset( szDir, 0, sizeof(szDir) ); memset( filename, 0, MAX_PATH ); memcpy( filename, path, len ); filename[len++] = '\\'; p = filename + len; filename[len++] = '*'; w_ret = MultiByteToWideChar( CP_ACP, 0, filename, (int)len, szDir, MAX_PATH - 3 ); if( w_ret == 0 ) return( MBEDTLS_ERR_X509_BAD_INPUT_DATA ); hFind = FindFirstFileW( szDir, &file_data ); if( hFind == INVALID_HANDLE_VALUE ) return( MBEDTLS_ERR_X509_FILE_IO_ERROR ); len = MAX_PATH - len; do { memset( p, 0, len ); if( file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY ) continue; w_ret = WideCharToMultiByte( CP_ACP, 0, file_data.cFileName, lstrlenW( file_data.cFileName ), p, (int) len - 1, NULL, NULL ); if( w_ret == 0 ) { ret = MBEDTLS_ERR_X509_FILE_IO_ERROR; goto cleanup; } w_ret = mbedtls_x509_crt_parse_file( chain, filename ); if( w_ret < 0 ) ret++; else ret += w_ret; } while( FindNextFileW( hFind, &file_data ) != 0 ); if( GetLastError() != ERROR_NO_MORE_FILES ) ret = MBEDTLS_ERR_X509_FILE_IO_ERROR; cleanup: FindClose( hFind ); #else /* _WIN32 */ int t_ret; int snp_ret; struct stat sb; struct dirent *entry; char entry_name[MBEDTLS_X509_MAX_FILE_PATH_LEN]; DIR *dir = opendir( path ); if( dir == NULL ) return( MBEDTLS_ERR_X509_FILE_IO_ERROR ); #if defined(MBEDTLS_THREADING_C) if( ( ret = mbedtls_mutex_lock( &mbedtls_threading_readdir_mutex ) ) != 0 ) { closedir( dir ); return( ret ); } #endif /* MBEDTLS_THREADING_C */ while( ( entry = readdir( dir ) ) != NULL ) { snp_ret = mbedtls_snprintf( entry_name, sizeof entry_name, "%s/%s", path, entry->d_name ); if( snp_ret < 0 || (size_t)snp_ret >= sizeof entry_name ) { ret = MBEDTLS_ERR_X509_BUFFER_TOO_SMALL; goto cleanup; } else if( stat( entry_name, &sb ) == -1 ) { ret = MBEDTLS_ERR_X509_FILE_IO_ERROR; goto cleanup; } if( !S_ISREG( sb.st_mode ) ) continue; // Ignore parse errors // t_ret = mbedtls_x509_crt_parse_file( chain, entry_name ); if( t_ret < 0 ) ret++; else ret += t_ret; } cleanup: closedir( dir ); #if defined(MBEDTLS_THREADING_C) if( mbedtls_mutex_unlock( &mbedtls_threading_readdir_mutex ) != 0 ) ret = MBEDTLS_ERR_THREADING_MUTEX_ERROR; #endif /* MBEDTLS_THREADING_C */ #endif /* _WIN32 */ return( ret ); } #endif /* MBEDTLS_FS_IO */ typedef struct mbedtls_x509_crt_sig_info { mbedtls_md_type_t sig_md; mbedtls_pk_type_t sig_pk; void *sig_opts; uint8_t crt_hash[MBEDTLS_MD_MAX_SIZE]; size_t crt_hash_len; mbedtls_x509_buf_raw sig; mbedtls_x509_buf_raw issuer_raw; } mbedtls_x509_crt_sig_info; static void x509_crt_free_sig_info( mbedtls_x509_crt_sig_info *info ) { #if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT) mbedtls_free( info->sig_opts ); #else ((void) info); #endif /* MBEDTLS_X509_RSASSA_PSS_SUPPORT */ } static int x509_crt_get_sig_info( mbedtls_x509_crt_frame const *frame, mbedtls_x509_crt_sig_info *info ) { const mbedtls_md_info_t *md_info; md_info = mbedtls_md_info_from_type( frame->sig_md ); if( mbedtls_md( md_info, frame->tbs.p, frame->tbs.len, info->crt_hash ) != 0 ) { /* Note: this can't happen except after an internal error */ return( -1 ); } info->crt_hash_len = mbedtls_md_get_size( md_info ); /* Make sure that this function leaves the target structure * ready to be freed, regardless of success of failure. */ info->sig_opts = NULL; #if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT) { int ret; unsigned char *alg_start = frame->sig_alg.p; unsigned char *alg_end = alg_start + frame->sig_alg.len; /* Get signature options -- currently only * necessary for RSASSA-PSS. */ ret = mbedtls_x509_get_sig_alg_raw( &alg_start, alg_end, &info->sig_md, &info->sig_pk, &info->sig_opts ); if( ret != 0 ) { /* Note: this can't happen except after an internal error */ return( -1 ); } } #else /* MBEDTLS_X509_RSASSA_PSS_SUPPORT */ info->sig_md = frame->sig_md; info->sig_pk = frame->sig_pk; #endif /* !MBEDTLS_X509_RSASSA_PSS_SUPPORT */ info->issuer_raw = frame->issuer_raw; info->sig = frame->sig; return( 0 ); } #if !defined(MBEDTLS_X509_REMOVE_INFO) static int x509_info_subject_alt_name( char **buf, size_t *size, const mbedtls_x509_sequence *subject_alt_name ) { size_t i; size_t n = *size; char *p = *buf; const mbedtls_x509_sequence *cur = subject_alt_name; const char *sep = ""; size_t sep_len = 0; while( cur != NULL ) { if( cur->buf.len + sep_len >= n ) { *p = '\0'; return( MBEDTLS_ERR_X509_BUFFER_TOO_SMALL ); } n -= cur->buf.len + sep_len; for( i = 0; i < sep_len; i++ ) *p++ = sep[i]; for( i = 0; i < cur->buf.len; i++ ) *p++ = cur->buf.p[i]; sep = ", "; sep_len = 2; cur = cur->next; } *p = '\0'; *size = n; *buf = p; return( 0 ); } #define PRINT_ITEM(i) \ { \ ret = mbedtls_snprintf( p, n, "%s" i, sep ); \ MBEDTLS_X509_SAFE_SNPRINTF; \ sep = ", "; \ } #define CERT_TYPE(type,name) \ if( ns_cert_type & (type) ) \ PRINT_ITEM( name ); static int x509_info_cert_type( char **buf, size_t *size, unsigned char ns_cert_type ) { int ret; size_t n = *size; char *p = *buf; const char *sep = ""; CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT, "SSL Client" ); CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER, "SSL Server" ); CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_EMAIL, "Email" ); CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING, "Object Signing" ); CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_RESERVED, "Reserved" ); CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_SSL_CA, "SSL CA" ); CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_EMAIL_CA, "Email CA" ); CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING_CA, "Object Signing CA" ); *size = n; *buf = p; return( 0 ); } #define KEY_USAGE(code,name) \ if( key_usage & (code) ) \ PRINT_ITEM( name ); static int x509_info_key_usage( char **buf, size_t *size, unsigned int key_usage ) { int ret; size_t n = *size; char *p = *buf; const char *sep = ""; KEY_USAGE( MBEDTLS_X509_KU_DIGITAL_SIGNATURE, "Digital Signature" ); KEY_USAGE( MBEDTLS_X509_KU_NON_REPUDIATION, "Non Repudiation" ); KEY_USAGE( MBEDTLS_X509_KU_KEY_ENCIPHERMENT, "Key Encipherment" ); KEY_USAGE( MBEDTLS_X509_KU_DATA_ENCIPHERMENT, "Data Encipherment" ); KEY_USAGE( MBEDTLS_X509_KU_KEY_AGREEMENT, "Key Agreement" ); KEY_USAGE( MBEDTLS_X509_KU_KEY_CERT_SIGN, "Key Cert Sign" ); KEY_USAGE( MBEDTLS_X509_KU_CRL_SIGN, "CRL Sign" ); KEY_USAGE( MBEDTLS_X509_KU_ENCIPHER_ONLY, "Encipher Only" ); KEY_USAGE( MBEDTLS_X509_KU_DECIPHER_ONLY, "Decipher Only" ); *size = n; *buf = p; return( 0 ); } static int x509_info_ext_key_usage( char **buf, size_t *size, const mbedtls_x509_sequence *extended_key_usage ) { int ret; const char *desc; size_t n = *size; char *p = *buf; const mbedtls_x509_sequence *cur = extended_key_usage; const char *sep = ""; while( cur != NULL ) { if( mbedtls_oid_get_extended_key_usage( &cur->buf, &desc ) != 0 ) desc = "???"; ret = mbedtls_snprintf( p, n, "%s%s", sep, desc ); MBEDTLS_X509_SAFE_SNPRINTF; sep = ", "; cur = cur->next; } *size = n; *buf = p; return( 0 ); } /* * Return an informational string about the certificate. */ #define BEFORE_COLON 18 #define BC "18" int mbedtls_x509_crt_info( char *buf, size_t size, const char *prefix, const mbedtls_x509_crt *crt ) { int ret; size_t n; char *p; char key_size_str[BEFORE_COLON]; mbedtls_x509_crt_frame frame; mbedtls_pk_context pk; mbedtls_x509_name *issuer = NULL, *subject = NULL; mbedtls_x509_sequence *ext_key_usage = NULL, *subject_alt_names = NULL; mbedtls_x509_crt_sig_info sig_info; p = buf; n = size; memset( &sig_info, 0, sizeof( mbedtls_x509_crt_sig_info ) ); mbedtls_pk_init( &pk ); if( NULL == crt ) { ret = mbedtls_snprintf( p, n, "\nCertificate is uninitialised!\n" ); MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP; return( (int) ( size - n ) ); } ret = mbedtls_x509_crt_get_frame( crt, &frame ); if( ret != 0 ) { ret = MBEDTLS_ERR_X509_FATAL_ERROR; goto cleanup; } ret = mbedtls_x509_crt_get_subject( crt, &subject ); if( ret != 0 ) { ret = MBEDTLS_ERR_X509_FATAL_ERROR; goto cleanup; } ret = mbedtls_x509_crt_get_issuer( crt, &issuer ); if( ret != 0 ) { ret = MBEDTLS_ERR_X509_FATAL_ERROR; goto cleanup; } ret = mbedtls_x509_crt_get_subject_alt_names( crt, &subject_alt_names ); if( ret != 0 ) { ret = MBEDTLS_ERR_X509_FATAL_ERROR; goto cleanup; } ret = mbedtls_x509_crt_get_ext_key_usage( crt, &ext_key_usage ); if( ret != 0 ) { ret = MBEDTLS_ERR_X509_FATAL_ERROR; goto cleanup; } ret = mbedtls_x509_crt_get_pk( crt, &pk ); if( ret != 0 ) { ret = MBEDTLS_ERR_X509_FATAL_ERROR; goto cleanup; } ret = x509_crt_get_sig_info( &frame, &sig_info ); if( ret != 0 ) { ret = MBEDTLS_ERR_X509_FATAL_ERROR; goto cleanup; } ret = mbedtls_snprintf( p, n, "%scert. version : %d\n", prefix, frame.version ); MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP; { mbedtls_x509_buf serial; serial.p = frame.serial.p; serial.len = frame.serial.len; ret = mbedtls_snprintf( p, n, "%sserial number : ", prefix ); MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP; ret = mbedtls_x509_serial_gets( p, n, &serial ); MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP; } ret = mbedtls_snprintf( p, n, "\n%sissuer name : ", prefix ); MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP; ret = mbedtls_x509_dn_gets( p, n, issuer ); MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP; ret = mbedtls_snprintf( p, n, "\n%ssubject name : ", prefix ); MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP; ret = mbedtls_x509_dn_gets( p, n, subject ); MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP; ret = mbedtls_snprintf( p, n, "\n%sissued on : " \ "%04d-%02d-%02d %02d:%02d:%02d", prefix, frame.valid_from.year, frame.valid_from.mon, frame.valid_from.day, frame.valid_from.hour, frame.valid_from.min, frame.valid_from.sec ); MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP; ret = mbedtls_snprintf( p, n, "\n%sexpires on : " \ "%04d-%02d-%02d %02d:%02d:%02d", prefix, frame.valid_to.year, frame.valid_to.mon, frame.valid_to.day, frame.valid_to.hour, frame.valid_to.min, frame.valid_to.sec ); MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP; ret = mbedtls_snprintf( p, n, "\n%ssigned using : ", prefix ); MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP; ret = mbedtls_x509_sig_alg_gets( p, n, sig_info.sig_pk, sig_info.sig_md, sig_info.sig_opts ); MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP; /* Key size */ if( ( ret = mbedtls_x509_key_size_helper( key_size_str, BEFORE_COLON, mbedtls_pk_get_name( &pk ) ) ) != 0 ) { return( ret ); } ret = mbedtls_snprintf( p, n, "\n%s%-" BC "s: %d bits", prefix, key_size_str, (int) mbedtls_pk_get_bitlen( &pk ) ); MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP; /* * Optional extensions */ if( frame.ext_types & MBEDTLS_X509_EXT_BASIC_CONSTRAINTS ) { ret = mbedtls_snprintf( p, n, "\n%sbasic constraints : CA=%s", prefix, frame.ca_istrue ? "true" : "false" ); MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP; if( frame.max_pathlen > 0 ) { ret = mbedtls_snprintf( p, n, ", max_pathlen=%d", frame.max_pathlen - 1 ); MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP; } } if( frame.ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME ) { ret = mbedtls_snprintf( p, n, "\n%ssubject alt name : ", prefix ); MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP; if( ( ret = x509_info_subject_alt_name( &p, &n, subject_alt_names ) ) != 0 ) return( ret ); } if( frame.ext_types & MBEDTLS_X509_EXT_NS_CERT_TYPE ) { ret = mbedtls_snprintf( p, n, "\n%scert. type : ", prefix ); MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP; if( ( ret = x509_info_cert_type( &p, &n, frame.ns_cert_type ) ) != 0 ) return( ret ); } if( frame.ext_types & MBEDTLS_X509_EXT_KEY_USAGE ) { ret = mbedtls_snprintf( p, n, "\n%skey usage : ", prefix ); MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP; if( ( ret = x509_info_key_usage( &p, &n, frame.key_usage ) ) != 0 ) return( ret ); } if( frame.ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE ) { ret = mbedtls_snprintf( p, n, "\n%sext key usage : ", prefix ); MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP; if( ( ret = x509_info_ext_key_usage( &p, &n, ext_key_usage ) ) != 0 ) return( ret ); } ret = mbedtls_snprintf( p, n, "\n" ); MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP; ret = (int) ( size - n ); cleanup: x509_crt_free_sig_info( &sig_info ); mbedtls_pk_free( &pk ); mbedtls_x509_name_free( issuer ); mbedtls_x509_name_free( subject ); mbedtls_x509_sequence_free( ext_key_usage ); mbedtls_x509_sequence_free( subject_alt_names ); return( ret ); } struct x509_crt_verify_string { int code; const char *string; }; static const struct x509_crt_verify_string x509_crt_verify_strings[] = { { MBEDTLS_X509_BADCERT_EXPIRED, "The certificate validity has expired" }, { MBEDTLS_X509_BADCERT_REVOKED, "The certificate has been revoked (is on a CRL)" }, { MBEDTLS_X509_BADCERT_CN_MISMATCH, "The certificate Common Name (CN) does not match with the expected CN" }, { MBEDTLS_X509_BADCERT_NOT_TRUSTED, "The certificate is not correctly signed by the trusted CA" }, { MBEDTLS_X509_BADCRL_NOT_TRUSTED, "The CRL is not correctly signed by the trusted CA" }, { MBEDTLS_X509_BADCRL_EXPIRED, "The CRL is expired" }, { MBEDTLS_X509_BADCERT_MISSING, "Certificate was missing" }, { MBEDTLS_X509_BADCERT_SKIP_VERIFY, "Certificate verification was skipped" }, { MBEDTLS_X509_BADCERT_OTHER, "Other reason (can be used by verify callback)" }, { MBEDTLS_X509_BADCERT_FUTURE, "The certificate validity starts in the future" }, { MBEDTLS_X509_BADCRL_FUTURE, "The CRL is from the future" }, { MBEDTLS_X509_BADCERT_KEY_USAGE, "Usage does not match the keyUsage extension" }, { MBEDTLS_X509_BADCERT_EXT_KEY_USAGE, "Usage does not match the extendedKeyUsage extension" }, { MBEDTLS_X509_BADCERT_NS_CERT_TYPE, "Usage does not match the nsCertType extension" }, { MBEDTLS_X509_BADCERT_BAD_MD, "The certificate is signed with an unacceptable hash." }, { MBEDTLS_X509_BADCERT_BAD_PK, "The certificate is signed with an unacceptable PK alg (eg RSA vs ECDSA)." }, { MBEDTLS_X509_BADCERT_BAD_KEY, "The certificate is signed with an unacceptable key (eg bad curve, RSA too short)." }, { MBEDTLS_X509_BADCRL_BAD_MD, "The CRL is signed with an unacceptable hash." }, { MBEDTLS_X509_BADCRL_BAD_PK, "The CRL is signed with an unacceptable PK alg (eg RSA vs ECDSA)." }, { MBEDTLS_X509_BADCRL_BAD_KEY, "The CRL is signed with an unacceptable key (eg bad curve, RSA too short)." }, { 0, NULL } }; int mbedtls_x509_crt_verify_info( char *buf, size_t size, const char *prefix, uint32_t flags ) { int ret; const struct x509_crt_verify_string *cur; char *p = buf; size_t n = size; for( cur = x509_crt_verify_strings; cur->string != NULL ; cur++ ) { if( ( flags & cur->code ) == 0 ) continue; ret = mbedtls_snprintf( p, n, "%s%s\n", prefix, cur->string ); MBEDTLS_X509_SAFE_SNPRINTF; flags ^= cur->code; } if( flags != 0 ) { ret = mbedtls_snprintf( p, n, "%sUnknown reason " "(this should not happen)\n", prefix ); MBEDTLS_X509_SAFE_SNPRINTF; } return( (int) ( size - n ) ); } #endif /* !MBEDTLS_X509_REMOVE_INFO */ #if defined(MBEDTLS_X509_CHECK_KEY_USAGE) static int x509_crt_check_key_usage_frame( const mbedtls_x509_crt_frame *crt, unsigned int usage ) { unsigned int usage_must, usage_may; unsigned int may_mask = MBEDTLS_X509_KU_ENCIPHER_ONLY | MBEDTLS_X509_KU_DECIPHER_ONLY; if( ( crt->ext_types & MBEDTLS_X509_EXT_KEY_USAGE ) == 0 ) return( 0 ); usage_must = usage & ~may_mask; if( ( ( crt->key_usage & ~may_mask ) & usage_must ) != usage_must ) return( MBEDTLS_ERR_X509_BAD_INPUT_DATA ); usage_may = usage & may_mask; if( ( ( crt->key_usage & may_mask ) | usage_may ) != usage_may ) return( MBEDTLS_ERR_X509_BAD_INPUT_DATA ); return( 0 ); } int mbedtls_x509_crt_check_key_usage( const mbedtls_x509_crt *crt, unsigned int usage ) { int ret; mbedtls_x509_crt_frame const *frame; ret = mbedtls_x509_crt_frame_acquire( crt, &frame ); if( ret != 0 ) return( MBEDTLS_ERR_X509_FATAL_ERROR ); ret = x509_crt_check_key_usage_frame( frame, usage ); mbedtls_x509_crt_frame_release( crt ); return( ret ); } #endif #if defined(MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE) typedef struct { const char *oid; size_t oid_len; } x509_crt_check_ext_key_usage_cb_ctx_t; static int x509_crt_check_ext_key_usage_cb( void *ctx, int tag, unsigned char *data, size_t data_len ) { x509_crt_check_ext_key_usage_cb_ctx_t *cb_ctx = (x509_crt_check_ext_key_usage_cb_ctx_t *) ctx; ((void) tag); if( MBEDTLS_OID_CMP_RAW( MBEDTLS_OID_ANY_EXTENDED_KEY_USAGE, data, data_len ) == 0 ) { return( 1 ); } if( data_len == cb_ctx->oid_len && memcmp( data, cb_ctx->oid, data_len ) == 0 ) { return( 1 ); } return( 0 ); } int mbedtls_x509_crt_check_extended_key_usage( const mbedtls_x509_crt *crt, const char *usage_oid, size_t usage_len ) { int ret; mbedtls_x509_crt_frame const *frame; unsigned ext_types; unsigned char *p, *end; x509_crt_check_ext_key_usage_cb_ctx_t cb_ctx = { usage_oid, usage_len }; ret = mbedtls_x509_crt_frame_acquire( crt, &frame ); if( ret != 0 ) return( MBEDTLS_ERR_X509_FATAL_ERROR ); /* Extension is not mandatory, absent means no restriction */ ext_types = frame->ext_types; if( ( ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE ) != 0 ) { p = frame->ext_key_usage_raw.p; end = p + frame->ext_key_usage_raw.len; ret = mbedtls_asn1_traverse_sequence_of( &p, end, 0xFF, MBEDTLS_ASN1_OID, 0, 0, x509_crt_check_ext_key_usage_cb, &cb_ctx ); if( ret == 1 ) ret = 0; else ret = MBEDTLS_ERR_X509_BAD_INPUT_DATA; } mbedtls_x509_crt_frame_release( crt ); return( ret ); } #endif /* MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE */ #if defined(MBEDTLS_X509_CRL_PARSE_C) /* * Return 1 if the certificate is revoked, or 0 otherwise. */ static int x509_serial_is_revoked( unsigned char const *serial, size_t serial_len, const mbedtls_x509_crl *crl ) { const mbedtls_x509_crl_entry *cur = &crl->entry; while( cur != NULL && cur->serial.len != 0 ) { if( serial_len == cur->serial.len && memcmp( serial, cur->serial.p, serial_len ) == 0 ) { if( mbedtls_x509_time_is_past( &cur->revocation_date ) ) return( 1 ); } cur = cur->next; } return( 0 ); } int mbedtls_x509_crt_is_revoked( const mbedtls_x509_crt *crt, const mbedtls_x509_crl *crl ) { int ret; mbedtls_x509_crt_frame const *frame; ret = mbedtls_x509_crt_frame_acquire( crt, &frame ); if( ret != 0 ) return( MBEDTLS_ERR_X509_FATAL_ERROR ); ret = x509_serial_is_revoked( frame->serial.p, frame->serial.len, crl ); mbedtls_x509_crt_frame_release( crt ); return( ret ); } /* * Check that the given certificate is not revoked according to the CRL. * Skip validation if no CRL for the given CA is present. */ static int x509_crt_verifycrl( unsigned char *crt_serial, size_t crt_serial_len, mbedtls_x509_crt *ca_crt, mbedtls_x509_crl *crl_list, const mbedtls_x509_crt_profile *profile ) { int ret; int flags = 0; unsigned char hash[MBEDTLS_MD_MAX_SIZE]; const mbedtls_md_info_t *md_info; mbedtls_x509_buf_raw ca_subject; mbedtls_pk_context *pk; int can_sign; if( ca_crt == NULL ) return( flags ); { mbedtls_x509_crt_frame const *ca; ret = mbedtls_x509_crt_frame_acquire( ca_crt, &ca ); if( ret != 0 ) return( MBEDTLS_X509_BADCRL_NOT_TRUSTED ); ca_subject = ca->subject_raw; can_sign = 0; if( x509_crt_check_key_usage_frame( ca, MBEDTLS_X509_KU_CRL_SIGN ) == 0 ) { can_sign = 1; } mbedtls_x509_crt_frame_release( ca_crt ); } ret = mbedtls_x509_crt_pk_acquire( ca_crt, &pk ); if( ret != 0 ) return( MBEDTLS_X509_BADCRL_NOT_TRUSTED ); while( crl_list != NULL ) { if( crl_list->version == 0 || mbedtls_x509_name_cmp_raw( &crl_list->issuer_raw, &ca_subject, NULL, NULL ) != 0 ) { crl_list = crl_list->next; continue; } /* * Check if the CA is configured to sign CRLs */ #if defined(MBEDTLS_X509_CHECK_KEY_USAGE) if( !can_sign ) { flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED; break; } #endif /* * Check if CRL is correctly signed by the trusted CA */ if( x509_profile_check_md_alg( profile, crl_list->sig_md ) != 0 ) flags |= MBEDTLS_X509_BADCRL_BAD_MD; if( x509_profile_check_pk_alg( profile, crl_list->sig_pk ) != 0 ) flags |= MBEDTLS_X509_BADCRL_BAD_PK; md_info = mbedtls_md_info_from_type( crl_list->sig_md ); if( mbedtls_md( md_info, crl_list->tbs.p, crl_list->tbs.len, hash ) != 0 ) { /* Note: this can't happen except after an internal error */ flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED; break; } if( x509_profile_check_key( profile, pk ) != 0 ) flags |= MBEDTLS_X509_BADCERT_BAD_KEY; if( mbedtls_pk_verify_ext( crl_list->sig_pk, crl_list->sig_opts, pk, crl_list->sig_md, hash, mbedtls_md_get_size( md_info ), crl_list->sig.p, crl_list->sig.len ) != 0 ) { flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED; break; } /* * Check for validity of CRL (Do not drop out) */ if( mbedtls_x509_time_is_past( &crl_list->next_update ) ) flags |= MBEDTLS_X509_BADCRL_EXPIRED; if( mbedtls_x509_time_is_future( &crl_list->this_update ) ) flags |= MBEDTLS_X509_BADCRL_FUTURE; /* * Check if certificate is revoked */ if( x509_serial_is_revoked( crt_serial, crt_serial_len, crl_list ) ) { flags |= MBEDTLS_X509_BADCERT_REVOKED; break; } crl_list = crl_list->next; } mbedtls_x509_crt_pk_release( ca_crt ); return( flags ); } #endif /* MBEDTLS_X509_CRL_PARSE_C */ /* * Check the signature of a certificate by its parent */ static int x509_crt_check_signature( const mbedtls_x509_crt_sig_info *sig_info, mbedtls_x509_crt *parent, mbedtls_x509_crt_restart_ctx *rs_ctx ) { int ret; mbedtls_pk_context *pk; ret = mbedtls_x509_crt_pk_acquire( parent, &pk ); if( ret != 0 ) return( MBEDTLS_ERR_X509_FATAL_ERROR ); /* Skip expensive computation on obvious mismatch */ if( ! mbedtls_pk_can_do( pk, sig_info->sig_pk ) ) { ret = -1; goto exit; } #if !( defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE) ) ((void) rs_ctx); #else if( rs_ctx != NULL && sig_info->sig_pk == MBEDTLS_PK_ECDSA ) { ret = mbedtls_pk_verify_restartable( pk, sig_info->sig_md, sig_info->crt_hash, sig_info->crt_hash_len, sig_info->sig.p, sig_info->sig.len, &rs_ctx->pk ); } else #endif { ret = mbedtls_pk_verify_ext( sig_info->sig_pk, sig_info->sig_opts, pk, sig_info->sig_md, sig_info->crt_hash, sig_info->crt_hash_len, sig_info->sig.p, sig_info->sig.len ); } exit: mbedtls_x509_crt_pk_release( parent ); return( ret ); } /* * Check if 'parent' is a suitable parent (signing CA) for 'child'. * Return 0 if yes, -1 if not. * * top means parent is a locally-trusted certificate */ static int x509_crt_check_parent( const mbedtls_x509_crt_sig_info *sig_info, const mbedtls_x509_crt_frame *parent, int top ) { int need_ca_bit; /* Parent must be the issuer */ if( mbedtls_x509_name_cmp_raw( &sig_info->issuer_raw, &parent->subject_raw, NULL, NULL ) != 0 ) { return( -1 ); } /* Parent must have the basicConstraints CA bit set as a general rule */ need_ca_bit = 1; /* Exception: v1/v2 certificates that are locally trusted. */ if( top && parent->version < 3 ) need_ca_bit = 0; if( need_ca_bit && ! parent->ca_istrue ) return( -1 ); #if defined(MBEDTLS_X509_CHECK_KEY_USAGE) if( need_ca_bit && x509_crt_check_key_usage_frame( parent, MBEDTLS_X509_KU_KEY_CERT_SIGN ) != 0 ) { return( -1 ); } #endif return( 0 ); } /* * Find a suitable parent for child in candidates, or return NULL. * * Here suitable is defined as: * 1. subject name matches child's issuer * 2. if necessary, the CA bit is set and key usage allows signing certs * 3. for trusted roots, the signature is correct * (for intermediates, the signature is checked and the result reported) * 4. pathlen constraints are satisfied * * If there's a suitable candidate which is also time-valid, return the first * such. Otherwise, return the first suitable candidate (or NULL if there is * none). * * The rationale for this rule is that someone could have a list of trusted * roots with two versions on the same root with different validity periods. * (At least one user reported having such a list and wanted it to just work.) * The reason we don't just require time-validity is that generally there is * only one version, and if it's expired we want the flags to state that * rather than NOT_TRUSTED, as would be the case if we required it here. * * The rationale for rule 3 (signature for trusted roots) is that users might * have two versions of the same CA with different keys in their list, and the * way we select the correct one is by checking the signature (as we don't * rely on key identifier extensions). (This is one way users might choose to * handle key rollover, another relies on self-issued certs, see [SIRO].) * * Arguments: * - [in] child: certificate for which we're looking for a parent * - [in] candidates: chained list of potential parents * - [out] r_parent: parent found (or NULL) * - [out] r_signature_is_good: 1 if child signature by parent is valid, or 0 * - [in] top: 1 if candidates consists of trusted roots, ie we're at the top * of the chain, 0 otherwise * - [in] path_cnt: number of intermediates seen so far * - [in] self_cnt: number of self-signed intermediates seen so far * (will never be greater than path_cnt) * - [in-out] rs_ctx: context for restarting operations * * Return value: * - 0 on success * - MBEDTLS_ERR_ECP_IN_PROGRESS otherwise */ static int x509_crt_find_parent_in( mbedtls_x509_crt_sig_info const *child_sig, mbedtls_x509_crt *candidates, mbedtls_x509_crt **r_parent, int *r_signature_is_good, int top, unsigned path_cnt, unsigned self_cnt, mbedtls_x509_crt_restart_ctx *rs_ctx ) { int ret; mbedtls_x509_crt *parent_crt, *fallback_parent; int signature_is_good, fallback_signature_is_good; #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE) /* did we have something in progress? */ if( rs_ctx != NULL && rs_ctx->parent != NULL ) { /* restore saved state */ parent_crt = rs_ctx->parent; fallback_parent = rs_ctx->fallback_parent; fallback_signature_is_good = rs_ctx->fallback_signature_is_good; /* clear saved state */ rs_ctx->parent = NULL; rs_ctx->fallback_parent = NULL; rs_ctx->fallback_signature_is_good = 0; /* resume where we left */ goto check_signature; } #endif fallback_parent = NULL; fallback_signature_is_good = 0; for( parent_crt = candidates; parent_crt != NULL; parent_crt = parent_crt->next ) { int parent_valid, parent_match, path_len_ok; #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE) check_signature: #endif parent_valid = parent_match = path_len_ok = 0; { mbedtls_x509_crt_frame const *parent; ret = mbedtls_x509_crt_frame_acquire( parent_crt, &parent ); if( ret != 0 ) return( MBEDTLS_ERR_X509_FATAL_ERROR ); if( !mbedtls_x509_time_is_past( &parent->valid_to ) && !mbedtls_x509_time_is_future( &parent->valid_from ) ) { parent_valid = 1; } /* basic parenting skills (name, CA bit, key usage) */ if( x509_crt_check_parent( child_sig, parent, top ) == 0 ) parent_match = 1; /* +1 because the stored max_pathlen is 1 higher * than the actual value */ if( !( parent->max_pathlen > 0 && (size_t) parent->max_pathlen < 1 + path_cnt - self_cnt ) ) { path_len_ok = 1; } mbedtls_x509_crt_frame_release( parent_crt ); } if( parent_match == 0 || path_len_ok == 0 ) continue; /* Signature */ ret = x509_crt_check_signature( child_sig, parent_crt, rs_ctx ); #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE) if( rs_ctx != NULL && ret == MBEDTLS_ERR_ECP_IN_PROGRESS ) { /* save state */ rs_ctx->parent = parent_crt; rs_ctx->fallback_parent = fallback_parent; rs_ctx->fallback_signature_is_good = fallback_signature_is_good; return( ret ); } #else (void) ret; #endif signature_is_good = ret == 0; if( top && ! signature_is_good ) continue; /* optional time check */ if( !parent_valid ) { if( fallback_parent == NULL ) { fallback_parent = parent_crt; fallback_signature_is_good = signature_is_good; } continue; } break; } if( parent_crt != NULL ) { *r_parent = parent_crt; *r_signature_is_good = signature_is_good; } else { *r_parent = fallback_parent; *r_signature_is_good = fallback_signature_is_good; } return( 0 ); } /* * Find a parent in trusted CAs or the provided chain, or return NULL. * * Searches in trusted CAs first, and return the first suitable parent found * (see find_parent_in() for definition of suitable). * * Arguments: * - [in] child: certificate for which we're looking for a parent, followed * by a chain of possible intermediates * - [in] trust_ca: list of locally trusted certificates * - [out] parent: parent found (or NULL) * - [out] parent_is_trusted: 1 if returned `parent` is trusted, or 0 * - [out] signature_is_good: 1 if child signature by parent is valid, or 0 * - [in] path_cnt: number of links in the chain so far (EE -> ... -> child) * - [in] self_cnt: number of self-signed certs in the chain so far * (will always be no greater than path_cnt) * - [in-out] rs_ctx: context for restarting operations * * Return value: * - 0 on success * - MBEDTLS_ERR_ECP_IN_PROGRESS otherwise */ static int x509_crt_find_parent( mbedtls_x509_crt_sig_info const *child_sig, mbedtls_x509_crt *rest, mbedtls_x509_crt *trust_ca, mbedtls_x509_crt **parent, int *parent_is_trusted, int *signature_is_good, unsigned path_cnt, unsigned self_cnt, mbedtls_x509_crt_restart_ctx *rs_ctx ) { int ret; mbedtls_x509_crt *search_list; *parent_is_trusted = 1; #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE) /* restore then clear saved state if we have some stored */ if( rs_ctx != NULL && rs_ctx->parent_is_trusted != -1 ) { *parent_is_trusted = rs_ctx->parent_is_trusted; rs_ctx->parent_is_trusted = -1; } #endif while( 1 ) { search_list = *parent_is_trusted ? trust_ca : rest; ret = x509_crt_find_parent_in( child_sig, search_list, parent, signature_is_good, *parent_is_trusted, path_cnt, self_cnt, rs_ctx ); #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE) if( rs_ctx != NULL && ret == MBEDTLS_ERR_ECP_IN_PROGRESS ) { /* save state */ rs_ctx->parent_is_trusted = *parent_is_trusted; return( ret ); } #else (void) ret; #endif /* stop here if found or already in second iteration */ if( *parent != NULL || *parent_is_trusted == 0 ) break; /* prepare second iteration */ *parent_is_trusted = 0; } /* extra precaution against mistakes in the caller */ if( *parent == NULL ) { *parent_is_trusted = 0; *signature_is_good = 0; } return( 0 ); } /* * Check if an end-entity certificate is locally trusted * * Currently we require such certificates to be self-signed (actually only * check for self-issued as self-signatures are not checked) */ static int x509_crt_check_ee_locally_trusted( mbedtls_x509_crt_frame const *crt, mbedtls_x509_crt const *trust_ca ) { mbedtls_x509_crt const *cur; /* look for an exact match with trusted cert */ for( cur = trust_ca; cur != NULL; cur = cur->next ) { if( crt->raw.len == cur->raw.len && memcmp( crt->raw.p, cur->raw.p, crt->raw.len ) == 0 ) { return( 0 ); } } /* too bad */ return( -1 ); } /* * Build and verify a certificate chain * * Given a peer-provided list of certificates EE, C1, ..., Cn and * a list of trusted certs R1, ... Rp, try to build and verify a chain * EE, Ci1, ... Ciq [, Rj] * such that every cert in the chain is a child of the next one, * jumping to a trusted root as early as possible. * * Verify that chain and return it with flags for all issues found. * * Special cases: * - EE == Rj -> return a one-element list containing it * - EE, Ci1, ..., Ciq cannot be continued with a trusted root * -> return that chain with NOT_TRUSTED set on Ciq * * Tests for (aspects of) this function should include at least: * - trusted EE * - EE -> trusted root * - EE -> intermediate CA -> trusted root * - if relevant: EE untrusted * - if relevant: EE -> intermediate, untrusted * with the aspect under test checked at each relevant level (EE, int, root). * For some aspects longer chains are required, but usually length 2 is * enough (but length 1 is not in general). * * Arguments: * - [in] crt: the cert list EE, C1, ..., Cn * - [in] trust_ca: the trusted list R1, ..., Rp * - [in] ca_crl, profile: as in verify_with_profile() * - [out] ver_chain: the built and verified chain * Only valid when return value is 0, may contain garbage otherwise! * Restart note: need not be the same when calling again to resume. * - [in-out] rs_ctx: context for restarting operations * * Return value: * - non-zero if the chain could not be fully built and examined * - 0 is the chain was successfully built and examined, * even if it was found to be invalid */ static int x509_crt_verify_chain( mbedtls_x509_crt *crt, mbedtls_x509_crt *trust_ca, mbedtls_x509_crl *ca_crl, const mbedtls_x509_crt_profile *profile, mbedtls_x509_crt_verify_chain *ver_chain, mbedtls_x509_crt_restart_ctx *rs_ctx ) { /* Don't initialize any of those variables here, so that the compiler can * catch potential issues with jumping ahead when restarting */ int ret; uint32_t *flags; mbedtls_x509_crt_verify_chain_item *cur; mbedtls_x509_crt *child_crt; mbedtls_x509_crt *parent_crt; int parent_is_trusted; int child_is_trusted; int signature_is_good; unsigned self_cnt; #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE) /* resume if we had an operation in progress */ if( rs_ctx != NULL && rs_ctx->in_progress == x509_crt_rs_find_parent ) { /* restore saved state */ *ver_chain = rs_ctx->ver_chain; /* struct copy */ self_cnt = rs_ctx->self_cnt; /* restore derived state */ cur = &ver_chain->items[ver_chain->len - 1]; child_crt = cur->crt; child_is_trusted = 0; goto find_parent; } #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */ child_crt = crt; self_cnt = 0; parent_is_trusted = 0; child_is_trusted = 0; while( 1 ) { #if defined(MBEDTLS_X509_CRL_PARSE_C) mbedtls_x509_buf_raw child_serial; #endif /* MBEDTLS_X509_CRL_PARSE_C */ int self_issued; /* Add certificate to the verification chain */ cur = &ver_chain->items[ver_chain->len]; cur->crt = child_crt; cur->flags = 0; ver_chain->len++; #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE) find_parent: #endif flags = &cur->flags; { mbedtls_x509_crt_sig_info child_sig; { mbedtls_x509_crt_frame const *child; ret = mbedtls_x509_crt_frame_acquire( child_crt, &child ); if( ret != 0 ) return( MBEDTLS_ERR_X509_FATAL_ERROR ); /* Check time-validity (all certificates) */ if( mbedtls_x509_time_is_past( &child->valid_to ) ) *flags |= MBEDTLS_X509_BADCERT_EXPIRED; if( mbedtls_x509_time_is_future( &child->valid_from ) ) *flags |= MBEDTLS_X509_BADCERT_FUTURE; /* Stop here for trusted roots (but not for trusted EE certs) */ if( child_is_trusted ) { mbedtls_x509_crt_frame_release( child_crt ); return( 0 ); } self_issued = 0; if( mbedtls_x509_name_cmp_raw( &child->issuer_raw, &child->subject_raw, NULL, NULL ) == 0 ) { self_issued = 1; } /* Check signature algorithm: MD & PK algs */ if( x509_profile_check_md_alg( profile, child->sig_md ) != 0 ) *flags |= MBEDTLS_X509_BADCERT_BAD_MD; if( x509_profile_check_pk_alg( profile, child->sig_pk ) != 0 ) *flags |= MBEDTLS_X509_BADCERT_BAD_PK; /* Special case: EE certs that are locally trusted */ if( ver_chain->len == 1 && self_issued && x509_crt_check_ee_locally_trusted( child, trust_ca ) == 0 ) { mbedtls_x509_crt_frame_release( child_crt ); return( 0 ); } #if defined(MBEDTLS_X509_CRL_PARSE_C) child_serial = child->serial; #endif /* MBEDTLS_X509_CRL_PARSE_C */ ret = x509_crt_get_sig_info( child, &child_sig ); mbedtls_x509_crt_frame_release( child_crt ); if( ret != 0 ) return( MBEDTLS_ERR_X509_FATAL_ERROR ); } /* Look for a parent in trusted CAs or up the chain */ ret = x509_crt_find_parent( &child_sig, child_crt->next, trust_ca, &parent_crt, &parent_is_trusted, &signature_is_good, ver_chain->len - 1, self_cnt, rs_ctx ); x509_crt_free_sig_info( &child_sig ); } #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE) if( rs_ctx != NULL && ret == MBEDTLS_ERR_ECP_IN_PROGRESS ) { /* save state */ rs_ctx->in_progress = x509_crt_rs_find_parent; rs_ctx->self_cnt = self_cnt; rs_ctx->ver_chain = *ver_chain; /* struct copy */ return( ret ); } #else (void) ret; #endif /* No parent? We're done here */ if( parent_crt == NULL ) { *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED; return( 0 ); } /* Count intermediate self-issued (not necessarily self-signed) certs. * These can occur with some strategies for key rollover, see [SIRO], * and should be excluded from max_pathlen checks. */ if( ver_chain->len != 1 && self_issued ) self_cnt++; /* path_cnt is 0 for the first intermediate CA, * and if parent is trusted it's not an intermediate CA */ if( ! parent_is_trusted && ver_chain->len > MBEDTLS_X509_MAX_INTERMEDIATE_CA ) { /* return immediately to avoid overflow the chain array */ return( MBEDTLS_ERR_X509_FATAL_ERROR ); } /* signature was checked while searching parent */ if( ! signature_is_good ) *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED; { mbedtls_pk_context *parent_pk; ret = mbedtls_x509_crt_pk_acquire( parent_crt, &parent_pk ); if( ret != 0 ) return( MBEDTLS_ERR_X509_FATAL_ERROR ); /* check size of signing key */ if( x509_profile_check_key( profile, parent_pk ) != 0 ) *flags |= MBEDTLS_X509_BADCERT_BAD_KEY; mbedtls_x509_crt_pk_release( parent_crt ); } #if defined(MBEDTLS_X509_CRL_PARSE_C) /* Check trusted CA's CRL for the given crt */ *flags |= x509_crt_verifycrl( child_serial.p, child_serial.len, parent_crt, ca_crl, profile ); #else (void) ca_crl; #endif /* prepare for next iteration */ child_crt = parent_crt; parent_crt = NULL; child_is_trusted = parent_is_trusted; signature_is_good = 0; } } /* * Check for CN match */ static int x509_crt_check_cn( unsigned char const *buf, size_t buflen, const char *cn, size_t cn_len ) { /* Try exact match */ if( mbedtls_x509_memcasecmp( cn, buf, buflen, cn_len ) == 0 ) return( 0 ); /* try wildcard match */ if( x509_check_wildcard( cn, cn_len, buf, buflen ) == 0 ) { return( 0 ); } return( -1 ); } /* Returns 1 on a match and 0 on a mismatch. * This is because this function is used as a callback for * mbedtls_x509_name_cmp_raw(), which continues the name * traversal as long as the callback returns 0. */ static int x509_crt_check_name( void *ctx, mbedtls_x509_buf *oid, mbedtls_x509_buf *val, int next_merged ) { char const *cn = (char const*) ctx; size_t cn_len = strlen( cn ); ((void) next_merged); if( MBEDTLS_OID_CMP( MBEDTLS_OID_AT_CN, oid ) == 0 && x509_crt_check_cn( val->p, val->len, cn, cn_len ) == 0 ) { return( 1 ); } return( 0 ); } /* Returns 1 on a match and 0 on a mismatch. * This is because this function is used as a callback for * mbedtls_asn1_traverse_sequence_of(), which continues the * traversal as long as the callback returns 0. */ static int x509_crt_subject_alt_check_name( void *ctx, int tag, unsigned char *data, size_t data_len ) { char const *cn = (char const*) ctx; size_t cn_len = strlen( cn ); ((void) tag); if( x509_crt_check_cn( data, data_len, cn, cn_len ) == 0 ) return( 1 ); return( 0 ); } /* * Verify the requested CN - only call this if cn is not NULL! */ static int x509_crt_verify_name( const mbedtls_x509_crt *crt, const char *cn, uint32_t *flags ) { int ret; mbedtls_x509_crt_frame const *frame; ret = mbedtls_x509_crt_frame_acquire( crt, &frame ); if( ret != 0 ) return( MBEDTLS_ERR_X509_FATAL_ERROR ); if( frame->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME ) { unsigned char *p = frame->subject_alt_raw.p; const unsigned char *end = frame->subject_alt_raw.p + frame->subject_alt_raw.len; ret = mbedtls_asn1_traverse_sequence_of( &p, end, MBEDTLS_ASN1_TAG_CLASS_MASK, MBEDTLS_ASN1_CONTEXT_SPECIFIC, MBEDTLS_ASN1_TAG_VALUE_MASK, 2 /* SubjectAlt DNS */, x509_crt_subject_alt_check_name, (void *) cn ); } else { ret = mbedtls_x509_name_cmp_raw( &frame->subject_raw, &frame->subject_raw, x509_crt_check_name, (void *) cn ); } mbedtls_x509_crt_frame_release( crt ); /* x509_crt_check_name() and x509_crt_subject_alt_check_name() * return 1 when finding a name component matching `cn`. */ if( ret == 1 ) return( 0 ); if( ret != 0 ) ret = MBEDTLS_ERR_X509_FATAL_ERROR; *flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH; return( ret ); } /* * Merge the flags for all certs in the chain, after calling callback */ static int x509_crt_merge_flags_with_cb( uint32_t *flags, const mbedtls_x509_crt_verify_chain *ver_chain, int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *), void *p_vrfy ) { int ret; unsigned i; uint32_t cur_flags; const mbedtls_x509_crt_verify_chain_item *cur; for( i = ver_chain->len; i != 0; --i ) { cur = &ver_chain->items[i-1]; cur_flags = cur->flags; if( NULL != f_vrfy ) if( ( ret = f_vrfy( p_vrfy, cur->crt, (int) i-1, &cur_flags ) ) != 0 ) return( ret ); *flags |= cur_flags; } return( 0 ); } /* * Verify the certificate validity (default profile, not restartable) */ int mbedtls_x509_crt_verify( mbedtls_x509_crt *crt, mbedtls_x509_crt *trust_ca, mbedtls_x509_crl *ca_crl, const char *cn, uint32_t *flags, int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *), void *p_vrfy ) { return( mbedtls_x509_crt_verify_restartable( crt, trust_ca, ca_crl, &mbedtls_x509_crt_profile_default, cn, flags, f_vrfy, p_vrfy, NULL ) ); } /* * Verify the certificate validity (user-chosen profile, not restartable) */ int mbedtls_x509_crt_verify_with_profile( mbedtls_x509_crt *crt, mbedtls_x509_crt *trust_ca, mbedtls_x509_crl *ca_crl, const mbedtls_x509_crt_profile *profile, const char *cn, uint32_t *flags, int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *), void *p_vrfy ) { return( mbedtls_x509_crt_verify_restartable( crt, trust_ca, ca_crl, profile, cn, flags, f_vrfy, p_vrfy, NULL ) ); } /* * Verify the certificate validity, with profile, restartable version * * This function: * - checks the requested CN (if any) * - checks the type and size of the EE cert's key, * as that isn't done as part of chain building/verification currently * - builds and verifies the chain * - then calls the callback and merges the flags */ int mbedtls_x509_crt_verify_restartable( mbedtls_x509_crt *crt, mbedtls_x509_crt *trust_ca, mbedtls_x509_crl *ca_crl, const mbedtls_x509_crt_profile *profile, const char *cn, uint32_t *flags, int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *), void *p_vrfy, mbedtls_x509_crt_restart_ctx *rs_ctx ) { int ret; mbedtls_x509_crt_verify_chain ver_chain; uint32_t ee_flags; *flags = 0; ee_flags = 0; x509_crt_verify_chain_reset( &ver_chain ); if( profile == NULL ) { ret = MBEDTLS_ERR_X509_BAD_INPUT_DATA; goto exit; } /* check name if requested */ if( cn != NULL ) { ret = x509_crt_verify_name( crt, cn, &ee_flags ); if( ret != 0 ) return( ret ); } { mbedtls_pk_context *pk; mbedtls_pk_type_t pk_type; ret = mbedtls_x509_crt_pk_acquire( crt, &pk ); if( ret != 0 ) return( MBEDTLS_ERR_X509_FATAL_ERROR ); /* Check the type and size of the key */ pk_type = mbedtls_pk_get_type( pk ); if( x509_profile_check_pk_alg( profile, pk_type ) != 0 ) ee_flags |= MBEDTLS_X509_BADCERT_BAD_PK; if( x509_profile_check_key( profile, pk ) != 0 ) ee_flags |= MBEDTLS_X509_BADCERT_BAD_KEY; mbedtls_x509_crt_pk_release( crt ); } /* Check the chain */ ret = x509_crt_verify_chain( crt, trust_ca, ca_crl, profile, &ver_chain, rs_ctx ); if( ret != 0 ) goto exit; /* Merge end-entity flags */ ver_chain.items[0].flags |= ee_flags; /* Build final flags, calling callback on the way if any */ ret = x509_crt_merge_flags_with_cb( flags, &ver_chain, f_vrfy, p_vrfy ); exit: #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE) if( rs_ctx != NULL && ret != MBEDTLS_ERR_ECP_IN_PROGRESS ) mbedtls_x509_crt_restart_free( rs_ctx ); #endif /* prevent misuse of the vrfy callback - VERIFY_FAILED would be ignored by * the SSL module for authmode optional, but non-zero return from the * callback means a fatal error so it shouldn't be ignored */ if( ret == MBEDTLS_ERR_X509_CERT_VERIFY_FAILED ) ret = MBEDTLS_ERR_X509_FATAL_ERROR; if( ret != 0 ) { *flags = (uint32_t) -1; return( ret ); } if( *flags != 0 ) return( MBEDTLS_ERR_X509_CERT_VERIFY_FAILED ); return( 0 ); } /* * Initialize a certificate chain */ void mbedtls_x509_crt_init( mbedtls_x509_crt *crt ) { memset( crt, 0, sizeof(mbedtls_x509_crt) ); } /* * Unallocate all certificate data */ void mbedtls_x509_crt_free( mbedtls_x509_crt *crt ) { mbedtls_x509_crt *cert_cur = crt; mbedtls_x509_crt *cert_prv; if( crt == NULL ) return; do { x509_crt_cache_free( cert_cur->cache ); mbedtls_free( cert_cur->cache ); #if !defined(MBEDTLS_X509_ON_DEMAND_PARSING) mbedtls_pk_free( &cert_cur->pk ); #if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT) mbedtls_free( cert_cur->sig_opts ); #endif mbedtls_x509_name_free( cert_cur->issuer.next ); mbedtls_x509_name_free( cert_cur->subject.next ); mbedtls_x509_sequence_free( cert_cur->ext_key_usage.next ); mbedtls_x509_sequence_free( cert_cur->subject_alt_names.next ); #endif /* !MBEDTLS_X509_ON_DEMAND_PARSING */ if( cert_cur->raw.p != NULL && cert_cur->own_buffer ) { mbedtls_platform_zeroize( cert_cur->raw.p, cert_cur->raw.len ); mbedtls_free( cert_cur->raw.p ); } cert_cur = cert_cur->next; } while( cert_cur != NULL ); cert_cur = crt; do { cert_prv = cert_cur; cert_cur = cert_cur->next; mbedtls_platform_zeroize( cert_prv, sizeof( mbedtls_x509_crt ) ); if( cert_prv != crt ) mbedtls_free( cert_prv ); } while( cert_cur != NULL ); } #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE) /* * Initialize a restart context */ void mbedtls_x509_crt_restart_init( mbedtls_x509_crt_restart_ctx *ctx ) { mbedtls_pk_restart_init( &ctx->pk ); ctx->parent = NULL; ctx->fallback_parent = NULL; ctx->fallback_signature_is_good = 0; ctx->parent_is_trusted = -1; ctx->in_progress = x509_crt_rs_none; ctx->self_cnt = 0; x509_crt_verify_chain_reset( &ctx->ver_chain ); } /* * Free the components of a restart context */ void mbedtls_x509_crt_restart_free( mbedtls_x509_crt_restart_ctx *ctx ) { if( ctx == NULL ) return; mbedtls_pk_restart_free( &ctx->pk ); mbedtls_x509_crt_restart_init( ctx ); } #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */ #endif /* MBEDTLS_X509_CRT_PARSE_C */