/* * 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/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 /* * 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 ); } /* * Like memcmp, but case-insensitive and always returns -1 if different */ static int x509_memcasecmp( const void *s1, const void *s2, size_t len ) { size_t i; unsigned char diff; const unsigned char *n1 = s1, *n2 = s2; for( i = 0; i < len; i++ ) { diff = n1[i] ^ n2[i]; if( diff == 0 ) continue; if( diff == 32 && ( ( n1[i] >= 'a' && n1[i] <= 'z' ) || ( n1[i] >= 'A' && n1[i] <= 'Z' ) ) ) { continue; } return( -1 ); } return( 0 ); } /* * Return 0 if name matches wildcard, -1 otherwise */ static int x509_check_wildcard( const char *cn, const mbedtls_x509_buf *name ) { size_t i; size_t cn_idx = 0, cn_len = strlen( cn ); /* We can't have a match if there is no wildcard to match */ if( name->len < 3 || name->p[0] != '*' || name->p[1] != '.' ) return( -1 ); for( i = 0; i < cn_len; ++i ) { if( cn[i] == '.' ) { cn_idx = i; break; } } if( cn_idx == 0 ) return( -1 ); if( cn_len - cn_idx == name->len - 1 && x509_memcasecmp( name->p + 1, cn + cn_idx, name->len - 1 ) == 0 ) { return( 0 ); } return( -1 ); } /* * Compare two X.509 strings, case-insensitive, and allowing for some encoding * variations (but not all). * * Return 0 if equal, -1 otherwise. */ static int x509_string_cmp( const mbedtls_x509_buf *a, const mbedtls_x509_buf *b ) { if( a->tag == b->tag && a->len == b->len && memcmp( a->p, b->p, b->len ) == 0 ) { return( 0 ); } if( ( a->tag == MBEDTLS_ASN1_UTF8_STRING || a->tag == MBEDTLS_ASN1_PRINTABLE_STRING ) && ( b->tag == MBEDTLS_ASN1_UTF8_STRING || b->tag == MBEDTLS_ASN1_PRINTABLE_STRING ) && a->len == b->len && x509_memcasecmp( a->p, b->p, b->len ) == 0 ) { return( 0 ); } return( -1 ); } /* * Compare two X.509 Names (aka rdnSequence). * * See RFC 5280 section 7.1, though we don't implement the whole algorithm: * we sometimes return unequal when the full algorithm would return equal, * but never the other way. (In particular, we don't do Unicode normalisation * or space folding.) * * Return 0 if equal, -1 otherwise. */ static int x509_name_cmp( const mbedtls_x509_name *a, const mbedtls_x509_name *b ) { /* Avoid recursion, it might not be optimised by the compiler */ while( a != NULL || b != NULL ) { if( a == NULL || b == NULL ) return( -1 ); /* type */ if( a->oid.tag != b->oid.tag || a->oid.len != b->oid.len || memcmp( a->oid.p, b->oid.p, b->oid.len ) != 0 ) { return( -1 ); } /* value */ if( x509_string_cmp( &a->val, &b->val ) != 0 ) return( -1 ); /* structure of the list of sets */ if( a->next_merged != b->next_merged ) return( -1 ); a = a->next; b = b->next; } /* a == NULL == b */ return( 0 ); } /* * 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( 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 *uid, int n ) { int ret; if( *p == end ) return( 0 ); uid->tag = **p; 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( 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( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + 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( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + 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( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret ); if( *p != end ) return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + 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( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret ); if( bs.len != 1 ) return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + 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, unsigned int *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( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret ); if( bs.len < 1 ) return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_INVALID_LENGTH ); /* Get actual bitstring */ *key_usage = 0; for( i = 0; i < bs.len && i < sizeof( unsigned int ); i++ ) { *key_usage |= (unsigned int) bs.p[i] << (8*i); } 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) { int ret; if( ( ret = mbedtls_asn1_get_sequence_of( p, end, ext_key_usage, MBEDTLS_ASN1_OID ) ) != 0 ) return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret ); /* Sequence length must be >= 1 */ if( ext_key_usage->buf.p == NULL ) return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_INVALID_LENGTH ); return( 0 ); } /* * 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 ) { int ret; size_t len, tag_len; mbedtls_asn1_buf *buf; unsigned char tag; mbedtls_asn1_sequence *cur = subject_alt_name; /* Get main sequence tag */ if( ( ret = mbedtls_asn1_get_tag( p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret ); if( *p + len != end ) return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ); while( *p < end ) { if( ( end - *p ) < 1 ) return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_OUT_OF_DATA ); tag = **p; (*p)++; if( ( ret = mbedtls_asn1_get_len( p, end, &tag_len ) ) != 0 ) return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret ); if( ( tag & MBEDTLS_ASN1_TAG_CLASS_MASK ) != MBEDTLS_ASN1_CONTEXT_SPECIFIC ) { return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ); } /* Skip everything but DNS name */ if( tag != ( MBEDTLS_ASN1_CONTEXT_SPECIFIC | 2 ) ) { *p += tag_len; continue; } /* Allocate and assign next pointer */ if( cur->buf.p != NULL ) { if( cur->next != NULL ) return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS ); cur->next = mbedtls_calloc( 1, sizeof( mbedtls_asn1_sequence ) ); if( cur->next == NULL ) return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_ALLOC_FAILED ); cur = cur->next; } buf = &(cur->buf); buf->tag = tag; buf->p = *p; buf->len = tag_len; *p += buf->len; } /* Set final sequence entry's next pointer to NULL */ cur->next = NULL; if( *p != end ) return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ); return( 0 ); } /* * X.509 v3 extensions * */ static int x509_get_crt_ext( unsigned char **p, const unsigned char *end, mbedtls_x509_crt *crt ) { int ret; size_t len; unsigned char *end_ext_data, *end_ext_octet; if( ( ret = mbedtls_x509_get_ext( p, end, &crt->v3_ext, 3 ) ) != 0 ) { if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) return( 0 ); return( ret ); } while( *p < end ) { /* * Extension ::= SEQUENCE { * extnID OBJECT IDENTIFIER, * critical BOOLEAN DEFAULT FALSE, * extnValue OCTET STRING } */ mbedtls_x509_buf extn_oid = {0, 0, NULL}; int is_critical = 0; /* DEFAULT FALSE */ int ext_type = 0; if( ( ret = mbedtls_asn1_get_tag( p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret ); end_ext_data = *p + len; /* Get extension ID */ if( ( ret = mbedtls_asn1_get_tag( p, end_ext_data, &extn_oid.len, MBEDTLS_ASN1_OID ) ) != 0 ) return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret ); 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_ext_data, &is_critical ) ) != 0 && ( ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) ) return( 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_ERR_X509_INVALID_EXTENSIONS + ret ); end_ext_octet = *p + len; if( end_ext_octet != end_ext_data ) return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ); /* * Detect supported extensions */ ret = mbedtls_oid_get_x509_ext_type( &extn_oid, &ext_type ); if( ret != 0 ) { /* No parser found, skip extension */ *p = end_ext_octet; #if !defined(MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION) if( is_critical ) { /* Data is marked as critical: fail */ return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ); } #endif continue; } /* Forbid repeated extensions */ if( ( crt->ext_types & ext_type ) != 0 ) return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS ); crt->ext_types |= ext_type; switch( ext_type ) { case MBEDTLS_X509_EXT_BASIC_CONSTRAINTS: /* Parse basic constraints */ if( ( ret = x509_get_basic_constraints( p, end_ext_octet, &crt->ca_istrue, &crt->max_pathlen ) ) != 0 ) return( ret ); break; case MBEDTLS_X509_EXT_KEY_USAGE: /* Parse key usage */ if( ( ret = x509_get_key_usage( p, end_ext_octet, &crt->key_usage ) ) != 0 ) return( ret ); break; case MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE: /* Parse extended key usage */ if( ( ret = x509_get_ext_key_usage( p, end_ext_octet, &crt->ext_key_usage ) ) != 0 ) return( ret ); break; case MBEDTLS_X509_EXT_SUBJECT_ALT_NAME: /* Parse subject alt name */ if( ( ret = x509_get_subject_alt_name( p, end_ext_octet, &crt->subject_alt_names ) ) != 0 ) return( ret ); break; case MBEDTLS_X509_EXT_NS_CERT_TYPE: /* Parse netscape certificate type */ if( ( ret = x509_get_ns_cert_type( p, end_ext_octet, &crt->ns_cert_type ) ) != 0 ) return( ret ); break; default: return( MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE ); } } if( *p != end ) return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ); return( 0 ); } /* * 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 ret; size_t len; unsigned char *p, *end, *crt_end; mbedtls_x509_buf sig_params1, sig_params2, sig_oid2; memset( &sig_params1, 0, sizeof( mbedtls_x509_buf ) ); memset( &sig_params2, 0, sizeof( mbedtls_x509_buf ) ); memset( &sig_oid2, 0, sizeof( mbedtls_x509_buf ) ); /* * Check for valid input */ if( crt == NULL || buf == NULL ) return( MBEDTLS_ERR_X509_BAD_INPUT_DATA ); // Use the original buffer until we figure out actual length p = (unsigned char*) buf; len = buflen; end = p + len; /* * Certificate ::= SEQUENCE { * tbsCertificate TBSCertificate, * signatureAlgorithm AlgorithmIdentifier, * signatureValue BIT STRING } */ if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) { mbedtls_x509_crt_free( crt ); return( MBEDTLS_ERR_X509_INVALID_FORMAT ); } if( len > (size_t) ( end - p ) ) { mbedtls_x509_crt_free( crt ); return( MBEDTLS_ERR_X509_INVALID_FORMAT + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ); } crt_end = p + len; // Create and populate a new buffer for the raw field crt->raw.len = crt_end - buf; crt->raw.p = p = mbedtls_calloc( 1, crt->raw.len ); if( p == NULL ) return( MBEDTLS_ERR_X509_ALLOC_FAILED ); memcpy( p, buf, crt->raw.len ); // Direct pointers to the new buffer p += crt->raw.len - len; end = crt_end = p + len; /* * TBSCertificate ::= SEQUENCE { */ crt->tbs.p = p; if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) { mbedtls_x509_crt_free( crt ); return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret ); } end = p + len; crt->tbs.len = end - crt->tbs.p; /* * Version ::= INTEGER { v1(0), v2(1), v3(2) } * * CertificateSerialNumber ::= INTEGER * * signature AlgorithmIdentifier */ if( ( ret = x509_get_version( &p, end, &crt->version ) ) != 0 || ( ret = mbedtls_x509_get_serial( &p, end, &crt->serial ) ) != 0 || ( ret = mbedtls_x509_get_alg( &p, end, &crt->sig_oid, &sig_params1 ) ) != 0 ) { mbedtls_x509_crt_free( crt ); return( ret ); } if( crt->version < 0 || crt->version > 2 ) { mbedtls_x509_crt_free( crt ); return( MBEDTLS_ERR_X509_UNKNOWN_VERSION ); } crt->version++; if( ( ret = mbedtls_x509_get_sig_alg( &crt->sig_oid, &sig_params1, &crt->sig_md, &crt->sig_pk, &crt->sig_opts ) ) != 0 ) { mbedtls_x509_crt_free( crt ); return( ret ); } /* * issuer Name */ crt->issuer_raw.p = p; if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) { mbedtls_x509_crt_free( crt ); return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret ); } if( ( ret = mbedtls_x509_get_name( &p, p + len, &crt->issuer ) ) != 0 ) { mbedtls_x509_crt_free( crt ); return( ret ); } crt->issuer_raw.len = p - crt->issuer_raw.p; /* * Validity ::= SEQUENCE { * notBefore Time, * notAfter Time } * */ if( ( ret = x509_get_dates( &p, end, &crt->valid_from, &crt->valid_to ) ) != 0 ) { mbedtls_x509_crt_free( crt ); return( ret ); } /* * subject Name */ crt->subject_raw.p = p; if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) { mbedtls_x509_crt_free( crt ); return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret ); } if( len && ( ret = mbedtls_x509_get_name( &p, p + len, &crt->subject ) ) != 0 ) { mbedtls_x509_crt_free( crt ); return( ret ); } crt->subject_raw.len = p - crt->subject_raw.p; /* * SubjectPublicKeyInfo */ if( ( ret = mbedtls_pk_parse_subpubkey( &p, end, &crt->pk ) ) != 0 ) { mbedtls_x509_crt_free( crt ); return( ret ); } /* * issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL, * -- If present, version shall be v2 or v3 * subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL, * -- If present, version shall be v2 or v3 * extensions [3] EXPLICIT Extensions OPTIONAL * -- If present, version shall be v3 */ if( crt->version == 2 || crt->version == 3 ) { ret = x509_get_uid( &p, end, &crt->issuer_id, 1 ); if( ret != 0 ) { mbedtls_x509_crt_free( crt ); return( ret ); } } if( crt->version == 2 || crt->version == 3 ) { ret = x509_get_uid( &p, end, &crt->subject_id, 2 ); if( ret != 0 ) { mbedtls_x509_crt_free( crt ); return( ret ); } } #if !defined(MBEDTLS_X509_ALLOW_EXTENSIONS_NON_V3) if( crt->version == 3 ) #endif { ret = x509_get_crt_ext( &p, end, crt ); if( ret != 0 ) { mbedtls_x509_crt_free( crt ); return( ret ); } } if( p != end ) { mbedtls_x509_crt_free( crt ); return( MBEDTLS_ERR_X509_INVALID_FORMAT + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ); } end = crt_end; /* * } * -- end of TBSCertificate * * signatureAlgorithm AlgorithmIdentifier, * signatureValue BIT STRING */ if( ( ret = mbedtls_x509_get_alg( &p, end, &sig_oid2, &sig_params2 ) ) != 0 ) { mbedtls_x509_crt_free( crt ); return( ret ); } if( crt->sig_oid.len != sig_oid2.len || memcmp( crt->sig_oid.p, sig_oid2.p, crt->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_crt_free( crt ); return( MBEDTLS_ERR_X509_SIG_MISMATCH ); } if( ( ret = mbedtls_x509_get_sig( &p, end, &crt->sig ) ) != 0 ) { mbedtls_x509_crt_free( crt ); return( ret ); } if( p != end ) { mbedtls_x509_crt_free( crt ); return( MBEDTLS_ERR_X509_INVALID_FORMAT + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ); } return( 0 ); } /* * Parse one X.509 certificate in DER format from a buffer and add them to a * chained list */ int mbedtls_x509_crt_parse_der( mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen ) { 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->version != 0 && crt->next != NULL ) { prev = crt; crt = crt->next; } /* * Add new certificate on the end of the chain if needed. */ if( crt->version != 0 && 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 ) ) != 0 ) { if( prev ) prev->next = NULL; if( crt != chain ) mbedtls_free( crt ); return( ret ); } return( 0 ); } /* * 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 */ 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]; p = buf; n = size; if( NULL == crt ) { ret = mbedtls_snprintf( p, n, "\nCertificate is uninitialised!\n" ); MBEDTLS_X509_SAFE_SNPRINTF; return( (int) ( size - n ) ); } ret = mbedtls_snprintf( p, n, "%scert. version : %d\n", prefix, crt->version ); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_snprintf( p, n, "%sserial number : ", prefix ); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_x509_serial_gets( p, n, &crt->serial ); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_snprintf( p, n, "\n%sissuer name : ", prefix ); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_x509_dn_gets( p, n, &crt->issuer ); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_snprintf( p, n, "\n%ssubject name : ", prefix ); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_x509_dn_gets( p, n, &crt->subject ); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_snprintf( p, n, "\n%sissued on : " \ "%04d-%02d-%02d %02d:%02d:%02d", prefix, crt->valid_from.year, crt->valid_from.mon, crt->valid_from.day, crt->valid_from.hour, crt->valid_from.min, crt->valid_from.sec ); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_snprintf( p, n, "\n%sexpires on : " \ "%04d-%02d-%02d %02d:%02d:%02d", prefix, crt->valid_to.year, crt->valid_to.mon, crt->valid_to.day, crt->valid_to.hour, crt->valid_to.min, crt->valid_to.sec ); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_snprintf( p, n, "\n%ssigned using : ", prefix ); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_x509_sig_alg_gets( p, n, &crt->sig_oid, crt->sig_pk, crt->sig_md, crt->sig_opts ); MBEDTLS_X509_SAFE_SNPRINTF; /* Key size */ if( ( ret = mbedtls_x509_key_size_helper( key_size_str, BEFORE_COLON, mbedtls_pk_get_name( &crt->pk ) ) ) != 0 ) { return( ret ); } ret = mbedtls_snprintf( p, n, "\n%s%-" BC "s: %d bits", prefix, key_size_str, (int) mbedtls_pk_get_bitlen( &crt->pk ) ); MBEDTLS_X509_SAFE_SNPRINTF; /* * Optional extensions */ if( crt->ext_types & MBEDTLS_X509_EXT_BASIC_CONSTRAINTS ) { ret = mbedtls_snprintf( p, n, "\n%sbasic constraints : CA=%s", prefix, crt->ca_istrue ? "true" : "false" ); MBEDTLS_X509_SAFE_SNPRINTF; if( crt->max_pathlen > 0 ) { ret = mbedtls_snprintf( p, n, ", max_pathlen=%d", crt->max_pathlen - 1 ); MBEDTLS_X509_SAFE_SNPRINTF; } } if( crt->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME ) { ret = mbedtls_snprintf( p, n, "\n%ssubject alt name : ", prefix ); MBEDTLS_X509_SAFE_SNPRINTF; if( ( ret = x509_info_subject_alt_name( &p, &n, &crt->subject_alt_names ) ) != 0 ) return( ret ); } if( crt->ext_types & MBEDTLS_X509_EXT_NS_CERT_TYPE ) { ret = mbedtls_snprintf( p, n, "\n%scert. type : ", prefix ); MBEDTLS_X509_SAFE_SNPRINTF; if( ( ret = x509_info_cert_type( &p, &n, crt->ns_cert_type ) ) != 0 ) return( ret ); } if( crt->ext_types & MBEDTLS_X509_EXT_KEY_USAGE ) { ret = mbedtls_snprintf( p, n, "\n%skey usage : ", prefix ); MBEDTLS_X509_SAFE_SNPRINTF; if( ( ret = x509_info_key_usage( &p, &n, crt->key_usage ) ) != 0 ) return( ret ); } if( crt->ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE ) { ret = mbedtls_snprintf( p, n, "\n%sext key usage : ", prefix ); MBEDTLS_X509_SAFE_SNPRINTF; if( ( ret = x509_info_ext_key_usage( &p, &n, &crt->ext_key_usage ) ) != 0 ) return( ret ); } ret = mbedtls_snprintf( p, n, "\n" ); MBEDTLS_X509_SAFE_SNPRINTF; return( (int) ( size - n ) ); } 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 ) ); } #if defined(MBEDTLS_X509_CHECK_KEY_USAGE) int mbedtls_x509_crt_check_key_usage( const mbedtls_x509_crt *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 ); } #endif #if defined(MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE) int mbedtls_x509_crt_check_extended_key_usage( const mbedtls_x509_crt *crt, const char *usage_oid, size_t usage_len ) { const mbedtls_x509_sequence *cur; /* Extension is not mandatory, absent means no restriction */ if( ( crt->ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE ) == 0 ) return( 0 ); /* * Look for the requested usage (or wildcard ANY) in our list */ for( cur = &crt->ext_key_usage; cur != NULL; cur = cur->next ) { const mbedtls_x509_buf *cur_oid = &cur->buf; if( cur_oid->len == usage_len && memcmp( cur_oid->p, usage_oid, usage_len ) == 0 ) { return( 0 ); } if( MBEDTLS_OID_CMP( MBEDTLS_OID_ANY_EXTENDED_KEY_USAGE, cur_oid ) == 0 ) return( 0 ); } return( MBEDTLS_ERR_X509_BAD_INPUT_DATA ); } #endif /* MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE */ #if defined(MBEDTLS_X509_CRL_PARSE_C) /* * Return 1 if the certificate is revoked, or 0 otherwise. */ int mbedtls_x509_crt_is_revoked( const mbedtls_x509_crt *crt, const mbedtls_x509_crl *crl ) { const mbedtls_x509_crl_entry *cur = &crl->entry; while( cur != NULL && cur->serial.len != 0 ) { if( crt->serial.len == cur->serial.len && memcmp( crt->serial.p, cur->serial.p, crt->serial.len ) == 0 ) { if( mbedtls_x509_time_is_past( &cur->revocation_date ) ) return( 1 ); } cur = cur->next; } return( 0 ); } /* * 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( mbedtls_x509_crt *crt, mbedtls_x509_crt *ca, mbedtls_x509_crl *crl_list, const mbedtls_x509_crt_profile *profile ) { int flags = 0; unsigned char hash[MBEDTLS_MD_MAX_SIZE]; const mbedtls_md_info_t *md_info; if( ca == NULL ) return( flags ); while( crl_list != NULL ) { if( crl_list->version == 0 || x509_name_cmp( &crl_list->issuer, &ca->subject ) != 0 ) { crl_list = crl_list->next; continue; } /* * Check if the CA is configured to sign CRLs */ #if defined(MBEDTLS_X509_CHECK_KEY_USAGE) if( mbedtls_x509_crt_check_key_usage( ca, MBEDTLS_X509_KU_CRL_SIGN ) != 0 ) { 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, &ca->pk ) != 0 ) flags |= MBEDTLS_X509_BADCERT_BAD_KEY; if( mbedtls_pk_verify_ext( crl_list->sig_pk, crl_list->sig_opts, &ca->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( mbedtls_x509_crt_is_revoked( crt, crl_list ) ) { flags |= MBEDTLS_X509_BADCERT_REVOKED; break; } crl_list = crl_list->next; } 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 *child, mbedtls_x509_crt *parent, mbedtls_x509_crt_restart_ctx *rs_ctx ) { const mbedtls_md_info_t *md_info; unsigned char hash[MBEDTLS_MD_MAX_SIZE]; md_info = mbedtls_md_info_from_type( child->sig_md ); if( mbedtls_md( md_info, child->tbs.p, child->tbs.len, hash ) != 0 ) { /* Note: this can't happen except after an internal error */ return( -1 ); } /* Skip expensive computation on obvious mismatch */ if( ! mbedtls_pk_can_do( &parent->pk, child->sig_pk ) ) return( -1 ); #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE) if( rs_ctx != NULL && child->sig_pk == MBEDTLS_PK_ECDSA ) { return( mbedtls_pk_verify_restartable( &parent->pk, child->sig_md, hash, mbedtls_md_get_size( md_info ), child->sig.p, child->sig.len, &rs_ctx->pk ) ); } #else (void) rs_ctx; #endif return( mbedtls_pk_verify_ext( child->sig_pk, child->sig_opts, &parent->pk, child->sig_md, hash, mbedtls_md_get_size( md_info ), child->sig.p, child->sig.len ) ); } /* * 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 *child, const mbedtls_x509_crt *parent, int top ) { int need_ca_bit; /* Parent must be the issuer */ if( x509_name_cmp( &child->issuer, &parent->subject ) != 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 && mbedtls_x509_crt_check_key_usage( 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 *child, 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, *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 = 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 = candidates; parent != NULL; parent = parent->next ) { /* basic parenting skills (name, CA bit, key usage) */ if( x509_crt_check_parent( child, parent, top ) != 0 ) continue; /* +1 because stored max_pathlen is 1 higher that the actual value */ if( parent->max_pathlen > 0 && (size_t) parent->max_pathlen < 1 + path_cnt - self_cnt ) { continue; } /* Signature */ #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE) check_signature: #endif ret = x509_crt_check_signature( child, parent, 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; 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( mbedtls_x509_time_is_past( &parent->valid_to ) || mbedtls_x509_time_is_future( &parent->valid_from ) ) { if( fallback_parent == NULL ) { fallback_parent = parent; fallback_signature_is_good = signature_is_good; } continue; } break; } if( parent != NULL ) { *r_parent = parent; *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 *child, 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 : child->next; ret = x509_crt_find_parent_in( child, 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 *crt, mbedtls_x509_crt *trust_ca ) { mbedtls_x509_crt *cur; /* must be self-issued */ if( x509_name_cmp( &crt->issuer, &crt->subject ) != 0 ) return( -1 ); /* 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 -> intermedate 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; mbedtls_x509_crt *parent; 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 = cur->crt; flags = &cur->flags; goto find_parent; } #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */ child = crt; self_cnt = 0; parent_is_trusted = 0; child_is_trusted = 0; while( 1 ) { /* Add certificate to the verification chain */ cur = &ver_chain->items[ver_chain->len]; cur->crt = child; cur->flags = 0; ver_chain->len++; flags = &cur->flags; /* 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 ) return( 0 ); /* 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 && x509_crt_check_ee_locally_trusted( child, trust_ca ) == 0 ) { return( 0 ); } #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE) find_parent: #endif /* Look for a parent in trusted CAs or up the chain */ ret = x509_crt_find_parent( child, trust_ca, &parent, &parent_is_trusted, &signature_is_good, ver_chain->len - 1, 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->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 == 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 && x509_name_cmp( &child->issuer, &child->subject ) == 0 ) { 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; /* check size of signing key */ if( x509_profile_check_key( profile, &parent->pk ) != 0 ) *flags |= MBEDTLS_X509_BADCERT_BAD_KEY; #if defined(MBEDTLS_X509_CRL_PARSE_C) /* Check trusted CA's CRL for the given crt */ *flags |= x509_crt_verifycrl( child, parent, ca_crl, profile ); #else (void) ca_crl; #endif /* prepare for next iteration */ child = parent; parent = NULL; child_is_trusted = parent_is_trusted; signature_is_good = 0; } } /* * Check for CN match */ static int x509_crt_check_cn( const mbedtls_x509_buf *name, const char *cn, size_t cn_len ) { /* try exact match */ if( name->len == cn_len && x509_memcasecmp( cn, name->p, cn_len ) == 0 ) { return( 0 ); } /* try wildcard match */ if( x509_check_wildcard( cn, name ) == 0 ) { return( 0 ); } return( -1 ); } /* * Verify the requested CN - only call this if cn is not NULL! */ static void x509_crt_verify_name( const mbedtls_x509_crt *crt, const char *cn, uint32_t *flags ) { const mbedtls_x509_name *name; const mbedtls_x509_sequence *cur; size_t cn_len = strlen( cn ); if( crt->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME ) { for( cur = &crt->subject_alt_names; cur != NULL; cur = cur->next ) { if( x509_crt_check_cn( &cur->buf, cn, cn_len ) == 0 ) break; } if( cur == NULL ) *flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH; } else { for( name = &crt->subject; name != NULL; name = name->next ) { if( MBEDTLS_OID_CMP( MBEDTLS_OID_AT_CN, &name->oid ) == 0 && x509_crt_check_cn( &name->val, cn, cn_len ) == 0 ) { break; } } if( name == NULL ) *flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH; } } /* * 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_pk_type_t pk_type; 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 ) x509_crt_verify_name( crt, cn, &ee_flags ); /* Check the type and size of the key */ pk_type = mbedtls_pk_get_type( &crt->pk ); if( x509_profile_check_pk_alg( profile, pk_type ) != 0 ) ee_flags |= MBEDTLS_X509_BADCERT_BAD_PK; if( x509_profile_check_key( profile, &crt->pk ) != 0 ) ee_flags |= MBEDTLS_X509_BADCERT_BAD_KEY; /* 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; mbedtls_x509_name *name_cur; mbedtls_x509_name *name_prv; mbedtls_x509_sequence *seq_cur; mbedtls_x509_sequence *seq_prv; if( crt == NULL ) return; do { mbedtls_pk_free( &cert_cur->pk ); #if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT) mbedtls_free( cert_cur->sig_opts ); #endif name_cur = cert_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 ); } name_cur = cert_cur->subject.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 ); } seq_cur = cert_cur->ext_key_usage.next; while( seq_cur != NULL ) { seq_prv = seq_cur; seq_cur = seq_cur->next; mbedtls_platform_zeroize( seq_prv, sizeof( mbedtls_x509_sequence ) ); mbedtls_free( seq_prv ); } seq_cur = cert_cur->subject_alt_names.next; while( seq_cur != NULL ) { seq_prv = seq_cur; seq_cur = seq_cur->next; mbedtls_platform_zeroize( seq_prv, sizeof( mbedtls_x509_sequence ) ); mbedtls_free( seq_prv ); } if( cert_cur->raw.p != NULL ) { 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 */