/* * X.509 certificate parsing and verification * * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved * SPDX-License-Identifier: GPL-2.0 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. * * 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 #include #if defined(MBEDTLS_PEM_PARSE_C) #include "mbedtls/pem.h" #endif #if defined(MBEDTLS_PLATFORM_C) #include "mbedtls/platform.h" #else #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); } /* * 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 || crl_list->issuer_raw.len != ca->subject_raw.len || memcmp(crl_list->issuer_raw.p, ca->subject_raw.p, crl_list->issuer_raw.len) != 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 */ /* * 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); } /* * Check the signature of a certificate by its parent */ static int x509_crt_check_signature(const mbedtls_x509_crt *child, mbedtls_x509_crt *parent) { 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); } if (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) != 0) { return (-1); } return (0); } /* * 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 * 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 * - [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) * * Return value: * - the first suitable parent found (see above regarding time-validity) * - NULL if no suitable parent was found */ static mbedtls_x509_crt *x509_crt_find_parent_in(mbedtls_x509_crt *child, mbedtls_x509_crt *candidates, int top, size_t path_cnt, size_t self_cnt) { mbedtls_x509_crt *parent, *badtime_parent = NULL; 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 (top && x509_crt_check_signature(child, parent) != 0) { continue; } /* optional time check */ if (mbedtls_x509_time_is_past(&parent->valid_to) || mbedtls_x509_time_is_future(&parent->valid_from)) { if (badtime_parent == NULL) badtime_parent = parent; continue; } break; } if (parent == NULL) parent = badtime_parent; return (parent); } /* * 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: locally trusted CAs * - [out] 1 if parent was found in trust_ca, 0 if found in provided chain * - [in] path_cnt: number of intermediates seen so far * - [in] self_cnt: number of self-signed intermediates seen so far * (will always be no greater than path_cnt) * * Return value: * - the first suitable parent found (see find_parent_in() for "suitable") * - NULL if no suitable parent was found */ static mbedtls_x509_crt *x509_crt_find_parent(mbedtls_x509_crt *child, mbedtls_x509_crt *trust_ca, int *parent_is_trusted, size_t path_cnt, size_t self_cnt) { mbedtls_x509_crt *parent; /* Look for a parent in trusted CAs */ *parent_is_trusted = 1; parent = x509_crt_find_parent_in(child, trust_ca, 1, path_cnt, self_cnt); if (parent != NULL) return (parent); /* Look for a parent upwards the chain */ *parent_is_trusted = 0; return (x509_crt_find_parent_in(child, child->next, 0, path_cnt, self_cnt)); } /* * 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 * * 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, chain_len: the built and verified chain * * 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, x509_crt_verify_chain_item ver_chain[X509_MAX_VERIFY_CHAIN_SIZE], size_t *chain_len) { uint32_t *flags; mbedtls_x509_crt *child; mbedtls_x509_crt *parent; int parent_is_trusted = 0; int child_is_trusted = 0; size_t self_cnt = 0; child = crt; *chain_len = 0; while (1) { /* Add certificate to the verification chain */ ver_chain[*chain_len].crt = child; flags = &ver_chain[*chain_len].flags; ++*chain_len; /* 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 (*chain_len == 1 && x509_crt_check_ee_locally_trusted(child, trust_ca) == 0) { return (0); } /* Look for a parent in trusted CAs or up the chain */ parent = x509_crt_find_parent(child, trust_ca, &parent_is_trusted, *chain_len - 1, self_cnt); /* 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 (*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 && *chain_len > MBEDTLS_X509_MAX_INTERMEDIATE_CA) { /* return immediately to avoid overflow the chain array */ return (MBEDTLS_ERR_X509_FATAL_ERROR); } /* if parent is trusted, the signature was checked by find_parent() */ if (! parent_is_trusted && x509_crt_check_signature(child, parent) != 0) *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; } } /* * 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, x509_crt_verify_chain_item ver_chain[X509_MAX_VERIFY_CHAIN_SIZE], size_t chain_len, int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *), void *p_vrfy) { int ret; size_t i; uint32_t cur_flags; for (i = chain_len; i != 0; --i) { cur_flags = ver_chain[i - 1].flags; if (NULL != f_vrfy) if ((ret = f_vrfy(p_vrfy, ver_chain[i - 1].crt, (int) i - 1, &cur_flags)) != 0) return (ret); *flags |= cur_flags; } return (0); } /* * Verify the certificate validity */ 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_with_profile(crt, trust_ca, ca_crl, &mbedtls_x509_crt_profile_default, cn, flags, f_vrfy, p_vrfy)); } /* * Verify the certificate validity, with profile * * 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_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) { int ret; mbedtls_pk_type_t pk_type; x509_crt_verify_chain_item ver_chain[X509_MAX_VERIFY_CHAIN_SIZE]; size_t chain_len; uint32_t *ee_flags = &ver_chain[0].flags; *flags = 0; memset(ver_chain, 0, sizeof(ver_chain)); chain_len = 0; 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, &chain_len); if (ret != 0) goto exit; /* Build final flags, calling callback on the way if any */ ret = x509_crt_merge_flags_with_cb(flags, ver_chain, chain_len, f_vrfy, p_vrfy); exit: /* 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); } #endif /* MBEDTLS_X509_CRT_PARSE_C */