/* * X.509 certificate parsing and verification * * Copyright The Mbed TLS Contributors * SPDX-License-Identifier: Apache-2.0 * * Licensed under the Apache License, Version 2.0 (the "License"); you may * not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /* * The ITU-T X.509 standard defines a certificate format for PKI. * * http://www.ietf.org/rfc/rfc5280.txt (Certificates and CRLs) * http://www.ietf.org/rfc/rfc3279.txt (Alg IDs for CRLs) * http://www.ietf.org/rfc/rfc2986.txt (CSRs, aka PKCS#10) * * http://www.itu.int/ITU-T/studygroups/com17/languages/X.680-0207.pdf * http://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf * * [SIRO] https://cabforum.org/wp-content/uploads/Chunghwatelecom201503cabforumV4.pdf */ #include "common.h" #if defined(MBEDTLS_X509_CRT_PARSE_C) #include "mbedtls/x509_crt.h" #include "mbedtls/error.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_USE_PSA_CRYPTO) #include "psa/crypto.h" #include "mbedtls/psa_util.h" #endif /* MBEDTLS_USE_PSA_CRYPTO */ #include "hash_info.h" #include "mbedtls/platform.h" #if defined(MBEDTLS_THREADING_C) #include "mbedtls/threading.h" #endif #if defined(MBEDTLS_HAVE_TIME) #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32) #include #else #include #endif #endif #if defined(MBEDTLS_FS_IO) #include #if !defined(_WIN32) || defined(EFIX64) || defined(EFI32) #include #include #if defined(__MBED__) #include #else #include #endif /* __MBED__ */ #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. Do not remove items unless there are serious security * concerns. */ const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_default = { /* Hashes from SHA-256 and above. Note that this selection * should be aligned with ssl_preset_default_hashes in ssl_tls.c. */ 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. Note that this selection * should be aligned with ssl_preset_default_curves in ssl_tls.c. */ 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) | 0, #else 0, #endif 2048, }; /* Next-generation profile. Currently identical to the default, but may * be tightened at any time. */ 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, }; /* * Empty / all-forbidden profile */ const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_none = { 0, 0, 0, (uint32_t) -1, }; /* * 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; #if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK) ver_chain->trust_ca_cb_result = NULL; #endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */ } /* * Version ::= INTEGER { v1(0), v2(1), v3(2) } */ static int x509_get_version(unsigned char **p, const unsigned char *end, int *ver) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t len; if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 0)) != 0) { if (ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG) { *ver = 0; return 0; } return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, ret); } end = *p + len; if ((ret = mbedtls_asn1_get_int(p, end, ver)) != 0) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_VERSION, ret); } if (*p != end) { return MBEDTLS_ERROR_ADD(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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t len; if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) { return MBEDTLS_ERROR_ADD(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_ERROR_ADD(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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 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 MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, ret); } uid->p = *p; *p += uid->len; return 0; } static int x509_get_basic_constraints(unsigned char **p, const unsigned char *end, int *ca_istrue, int *max_pathlen) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 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_ERROR_ADD(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_ERROR_ADD(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_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret); } if (*p != end) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, MBEDTLS_ERR_ASN1_LENGTH_MISMATCH); } /* Do not accept max_pathlen equal to INT_MAX to avoid a signed integer * overflow, which is an undefined behavior. */ if (*max_pathlen == INT_MAX) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, MBEDTLS_ERR_ASN1_INVALID_LENGTH); } (*max_pathlen)++; 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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; if ((ret = mbedtls_asn1_get_sequence_of(p, end, ext_key_usage, MBEDTLS_ASN1_OID)) != 0) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret); } /* Sequence length must be >= 1 */ if (ext_key_usage->buf.p == NULL) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, MBEDTLS_ERR_ASN1_INVALID_LENGTH); } return 0; } /* * SubjectKeyIdentifier ::= KeyIdentifier * * KeyIdentifier ::= OCTET STRING */ static int x509_get_subject_key_id(unsigned char **p, const unsigned char *end, mbedtls_x509_buf *subject_key_id) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t len = 0u; if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_OCTET_STRING)) != 0) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret); } else { subject_key_id->len = len; subject_key_id->tag = MBEDTLS_ASN1_OCTET_STRING; subject_key_id->p = *p; *p += len; } if (*p != end) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, MBEDTLS_ERR_ASN1_LENGTH_MISMATCH); } return 0; } /* * AuthorityKeyIdentifier ::= SEQUENCE { * keyIdentifier [0] KeyIdentifier OPTIONAL, * authorityCertIssuer [1] GeneralNames OPTIONAL, * authorityCertSerialNumber [2] CertificateSerialNumber OPTIONAL } * * KeyIdentifier ::= OCTET STRING */ static int x509_get_authority_key_id(unsigned char **p, unsigned char *end, mbedtls_x509_authority *authority_key_id) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t len = 0u; if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret); } if (*p + len != end) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, MBEDTLS_ERR_ASN1_LENGTH_MISMATCH); } if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_CONTEXT_SPECIFIC)) != 0) { /* KeyIdentifier is an OPTIONAL field */ } else { authority_key_id->keyIdentifier.len = len; authority_key_id->keyIdentifier.p = *p; /* Setting tag of the keyIdentfier intentionally to 0x04. * Although the .keyIdentfier field is CONTEXT_SPECIFIC ([0] OPTIONAL), * its tag with the content is the payload of on OCTET STRING primitive */ authority_key_id->keyIdentifier.tag = MBEDTLS_ASN1_OCTET_STRING; *p += len; } if (*p < end) { /* Getting authorityCertIssuer using the required specific class tag [1] */ if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 1)) != 0) { /* authorityCertIssuer is an OPTIONAL field */ } else { /* "end" also includes the CertSerialNumber field so "len" shall be used */ ret = mbedtls_x509_get_subject_alt_name_ext(p, (*p+len), &authority_key_id->authorityCertIssuer); } } if (*p < end) { /* Getting authorityCertSerialNumber using the required specific class tag [2] */ if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_INTEGER | 2)) != 0) { /* authorityCertSerialNumber is an OPTIONAL field */ return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret); } else { authority_key_id->authorityCertSerialNumber.len = len; authority_key_id->authorityCertSerialNumber.p = *p; authority_key_id->authorityCertSerialNumber.tag = MBEDTLS_ASN1_OCTET_STRING; *p += len; } } if (*p != end) { return MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH; } return 0; } /* * id-ce-certificatePolicies OBJECT IDENTIFIER ::= { id-ce 32 } * * anyPolicy OBJECT IDENTIFIER ::= { id-ce-certificatePolicies 0 } * * certificatePolicies ::= SEQUENCE SIZE (1..MAX) OF PolicyInformation * * PolicyInformation ::= SEQUENCE { * policyIdentifier CertPolicyId, * policyQualifiers SEQUENCE SIZE (1..MAX) OF * PolicyQualifierInfo OPTIONAL } * * CertPolicyId ::= OBJECT IDENTIFIER * * PolicyQualifierInfo ::= SEQUENCE { * policyQualifierId PolicyQualifierId, * qualifier ANY DEFINED BY policyQualifierId } * * -- policyQualifierIds for Internet policy qualifiers * * id-qt OBJECT IDENTIFIER ::= { id-pkix 2 } * id-qt-cps OBJECT IDENTIFIER ::= { id-qt 1 } * id-qt-unotice OBJECT IDENTIFIER ::= { id-qt 2 } * * PolicyQualifierId ::= OBJECT IDENTIFIER ( id-qt-cps | id-qt-unotice ) * * Qualifier ::= CHOICE { * cPSuri CPSuri, * userNotice UserNotice } * * CPSuri ::= IA5String * * UserNotice ::= SEQUENCE { * noticeRef NoticeReference OPTIONAL, * explicitText DisplayText OPTIONAL } * * NoticeReference ::= SEQUENCE { * organization DisplayText, * noticeNumbers SEQUENCE OF INTEGER } * * DisplayText ::= CHOICE { * ia5String IA5String (SIZE (1..200)), * visibleString VisibleString (SIZE (1..200)), * bmpString BMPString (SIZE (1..200)), * utf8String UTF8String (SIZE (1..200)) } * * NOTE: we only parse and use anyPolicy without qualifiers at this point * as defined in RFC 5280. */ static int x509_get_certificate_policies(unsigned char **p, const unsigned char *end, mbedtls_x509_sequence *certificate_policies) { int ret, parse_ret = 0; size_t len; mbedtls_asn1_buf *buf; mbedtls_asn1_sequence *cur = certificate_policies; /* Get main sequence tag */ ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE); if (ret != 0) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret); } if (*p + len != end) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, MBEDTLS_ERR_ASN1_LENGTH_MISMATCH); } /* * Cannot be an empty sequence. */ if (len == 0) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, MBEDTLS_ERR_ASN1_LENGTH_MISMATCH); } while (*p < end) { mbedtls_x509_buf policy_oid; const unsigned char *policy_end; /* * Get the policy sequence */ if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret); } policy_end = *p + len; if ((ret = mbedtls_asn1_get_tag(p, policy_end, &len, MBEDTLS_ASN1_OID)) != 0) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret); } policy_oid.tag = MBEDTLS_ASN1_OID; policy_oid.len = len; policy_oid.p = *p; /* * Only AnyPolicy is currently supported when enforcing policy. */ if (MBEDTLS_OID_CMP(MBEDTLS_OID_ANY_POLICY, &policy_oid) != 0) { /* * Set the parsing return code but continue parsing, in case this * extension is critical. */ parse_ret = MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE; } /* 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_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, MBEDTLS_ERR_ASN1_ALLOC_FAILED); } cur = cur->next; } buf = &(cur->buf); buf->tag = policy_oid.tag; buf->p = policy_oid.p; buf->len = policy_oid.len; *p += len; /* * If there is an optional qualifier, then *p < policy_end * Check the Qualifier len to verify it doesn't exceed policy_end. */ if (*p < policy_end) { if ((ret = mbedtls_asn1_get_tag(p, policy_end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret); } /* * Skip the optional policy qualifiers. */ *p += len; } if (*p != policy_end) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, MBEDTLS_ERR_ASN1_LENGTH_MISMATCH); } } /* Set final sequence entry's next pointer to NULL */ cur->next = NULL; if (*p != end) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, MBEDTLS_ERR_ASN1_LENGTH_MISMATCH); } return parse_ret; } /* * X.509 v3 extensions * */ static int x509_get_crt_ext(unsigned char **p, const unsigned char *end, mbedtls_x509_crt *crt, mbedtls_x509_crt_ext_cb_t cb, void *p_ctx) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t len; unsigned char *end_ext_data, *start_ext_octet, *end_ext_octet; if (*p == end) { return 0; } if ((ret = mbedtls_x509_get_ext(p, end, &crt->v3_ext, 3)) != 0) { return ret; } end = crt->v3_ext.p + crt->v3_ext.len; 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_ERROR_ADD(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_ERROR_ADD(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_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret); } /* Data should be octet string type */ if ((ret = mbedtls_asn1_get_tag(p, end_ext_data, &len, MBEDTLS_ASN1_OCTET_STRING)) != 0) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret); } start_ext_octet = *p; end_ext_octet = *p + len; if (end_ext_octet != end_ext_data) { return MBEDTLS_ERROR_ADD(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) { /* Give the callback (if any) a chance to handle the extension */ if (cb != NULL) { ret = cb(p_ctx, crt, &extn_oid, is_critical, *p, end_ext_octet); if (ret != 0 && is_critical) { return ret; } *p = end_ext_octet; continue; } /* No parser found, skip extension */ *p = end_ext_octet; if (is_critical) { /* Data is marked as critical: fail */ return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, MBEDTLS_ERR_ASN1_UNEXPECTED_TAG); } 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 = mbedtls_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_KEY_IDENTIFIER: /* Parse subject key identifier */ if ((ret = x509_get_subject_key_id(p, end_ext_data, &crt->subject_key_id)) != 0) { return ret; } break; case MBEDTLS_X509_EXT_AUTHORITY_KEY_IDENTIFIER: /* Parse authority key identifier */ if ((ret = x509_get_authority_key_id(p, end_ext_octet, &crt->authority_key_id)) != 0) { return ret; } break; case MBEDTLS_X509_EXT_SUBJECT_ALT_NAME: /* Parse subject alt name * SubjectAltName ::= GeneralNames */ if ((ret = mbedtls_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 = mbedtls_x509_get_ns_cert_type(p, end_ext_octet, &crt->ns_cert_type)) != 0) { return ret; } break; case MBEDTLS_OID_X509_EXT_CERTIFICATE_POLICIES: /* Parse certificate policies type */ if ((ret = x509_get_certificate_policies(p, end_ext_octet, &crt->certificate_policies)) != 0) { /* Give the callback (if any) a chance to handle the extension * if it contains unsupported policies */ if (ret == MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE && cb != NULL && cb(p_ctx, crt, &extn_oid, is_critical, start_ext_octet, end_ext_octet) == 0) { break; } if (is_critical) { return ret; } else /* * If MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE is returned, then we * cannot interpret or enforce the policy. However, it is up to * the user to choose how to enforce the policies, * unless the extension is critical. */ if (ret != MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE) { return ret; } } break; default: /* * If this is a non-critical extension, which the oid layer * supports, but there isn't an x509 parser for it, * skip the extension. */ if (is_critical) { return MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE; } else { *p = end_ext_octet; } } } if (*p != end) { return MBEDTLS_ERROR_ADD(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 make_copy, mbedtls_x509_crt_ext_cb_t cb, void *p_ctx) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 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; } end = crt_end = p + len; crt->raw.len = crt_end - buf; if (make_copy != 0) { /* Create and populate a new buffer for the raw field. */ crt->raw.p = p = mbedtls_calloc(1, crt->raw.len); if (crt->raw.p == NULL) { return MBEDTLS_ERR_X509_ALLOC_FAILED; } memcpy(crt->raw.p, buf, crt->raw.len); crt->own_buffer = 1; p += crt->raw.len - len; end = crt_end = p + len; } else { crt->raw.p = (unsigned char *) buf; crt->own_buffer = 0; } /* * 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_ERROR_ADD(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_ERROR_ADD(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_ERROR_ADD(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 */ crt->pk_raw.p = p; if ((ret = mbedtls_pk_parse_subpubkey(&p, end, &crt->pk)) != 0) { mbedtls_x509_crt_free(crt); return ret; } crt->pk_raw.len = p - crt->pk_raw.p; /* * 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 (crt->version == 3) { ret = x509_get_crt_ext(&p, end, crt, cb, p_ctx); if (ret != 0) { mbedtls_x509_crt_free(crt); return ret; } } if (p != end) { mbedtls_x509_crt_free(crt); return MBEDTLS_ERROR_ADD(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.tag != sig_params2.tag || 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_ERROR_ADD(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 */ static int mbedtls_x509_crt_parse_der_internal(mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen, int make_copy, mbedtls_x509_crt_ext_cb_t cb, void *p_ctx) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 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; } ret = x509_crt_parse_der_core(crt, buf, buflen, make_copy, cb, p_ctx); if (ret != 0) { if (prev) { prev->next = NULL; } if (crt != chain) { mbedtls_free(crt); } return ret; } return 0; } int mbedtls_x509_crt_parse_der_nocopy(mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen) { return mbedtls_x509_crt_parse_der_internal(chain, buf, buflen, 0, NULL, NULL); } int mbedtls_x509_crt_parse_der_with_ext_cb(mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen, int make_copy, mbedtls_x509_crt_ext_cb_t cb, void *p_ctx) { return mbedtls_x509_crt_parse_der_internal(chain, buf, buflen, make_copy, cb, p_ctx); } int mbedtls_x509_crt_parse_der(mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen) { return mbedtls_x509_crt_parse_der_internal(chain, buf, buflen, 1, NULL, NULL); } /* * 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_ERR_ERROR_CORRUPTION_DETECTED; 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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t n; unsigned char *buf; if ((ret = mbedtls_pk_load_file(path, &buf, &n)) != 0) { return ret; } ret = mbedtls_x509_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, -1, p, (int) len, 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 */ memset(&sb, 0, sizeof(sb)); 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) { if (errno == ENOENT) { /* Broken symbolic link - ignore this entry. stat(2) will return this error for either (a) a dangling symlink or (b) a missing file. Given that we have just obtained the filename from readdir, assume that it does exist and therefore treat this as a dangling symlink. */ continue; } else { /* Some other file error; report the error. */ 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 */ #if !defined(MBEDTLS_X509_REMOVE_INFO) #define PRINT_ITEM(i) \ do { \ ret = mbedtls_snprintf(p, n, "%s" i, sep); \ MBEDTLS_X509_SAFE_SNPRINTF; \ sep = ", "; \ } while (0) #define CERT_TYPE(type, name) \ do { \ if (ns_cert_type & (type)) \ PRINT_ITEM(name); \ } while (0) #define KEY_USAGE(code, name) \ do { \ if (key_usage & (code)) \ PRINT_ITEM(name); \ } while (0) static int x509_info_ext_key_usage(char **buf, size_t *size, const mbedtls_x509_sequence *extended_key_usage) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 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; } static int x509_info_cert_policies(char **buf, size_t *size, const mbedtls_x509_sequence *certificate_policies) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; const char *desc; size_t n = *size; char *p = *buf; const mbedtls_x509_sequence *cur = certificate_policies; const char *sep = ""; while (cur != NULL) { if (mbedtls_oid_get_certificate_policies(&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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 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 = mbedtls_x509_info_subject_alt_name(&p, &n, &crt->subject_alt_names, prefix)) != 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 = mbedtls_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 = mbedtls_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; } } if (crt->ext_types & MBEDTLS_OID_X509_EXT_CERTIFICATE_POLICIES) { ret = mbedtls_snprintf(p, n, "\n%scertificate policies : ", prefix); MBEDTLS_X509_SAFE_SNPRINTF; if ((ret = x509_info_cert_policies(&p, &n, &crt->certificate_policies)) != 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; }; #define X509_CRT_ERROR_INFO(err, err_str, info) { err, info }, static const struct x509_crt_verify_string x509_crt_verify_strings[] = { MBEDTLS_X509_CRT_ERROR_INFO_LIST { 0, NULL } }; #undef X509_CRT_ERROR_INFO int mbedtls_x509_crt_verify_info(char *buf, size_t size, const char *prefix, uint32_t flags) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; const struct x509_crt_verify_string *cur; char *p = buf; size_t n = size; for (cur = x509_crt_verify_strings; cur->string != NULL; cur++) { if ((flags & cur->code) == 0) { continue; } ret = mbedtls_snprintf(p, n, "%s%s\n", prefix, cur->string); MBEDTLS_X509_SAFE_SNPRINTF; flags ^= cur->code; } if (flags != 0) { ret = mbedtls_snprintf(p, n, "%sUnknown reason " "(this should not happen)\n", prefix); MBEDTLS_X509_SAFE_SNPRINTF; } return (int) (size - n); } #endif /* MBEDTLS_X509_REMOVE_INFO */ 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; } 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; } #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) { 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_HASH_MAX_SIZE]; #if defined(MBEDTLS_USE_PSA_CRYPTO) psa_algorithm_t psa_algorithm; #else const mbedtls_md_info_t *md_info; #endif /* MBEDTLS_USE_PSA_CRYPTO */ size_t hash_length; 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 (mbedtls_x509_crt_check_key_usage(ca, MBEDTLS_X509_KU_CRL_SIGN) != 0) { flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED; break; } /* * 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; } #if defined(MBEDTLS_USE_PSA_CRYPTO) psa_algorithm = mbedtls_hash_info_psa_from_md(crl_list->sig_md); if (psa_hash_compute(psa_algorithm, crl_list->tbs.p, crl_list->tbs.len, hash, sizeof(hash), &hash_length) != PSA_SUCCESS) { /* Note: this can't happen except after an internal error */ flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED; break; } #else md_info = mbedtls_md_info_from_type(crl_list->sig_md); hash_length = mbedtls_md_get_size(md_info); 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; } #endif /* MBEDTLS_USE_PSA_CRYPTO */ 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, hash_length, 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) { size_t hash_len; unsigned char hash[MBEDTLS_HASH_MAX_SIZE]; #if !defined(MBEDTLS_USE_PSA_CRYPTO) const mbedtls_md_info_t *md_info; md_info = mbedtls_md_info_from_type(child->sig_md); hash_len = mbedtls_md_get_size(md_info); /* Note: hash errors can happen only after an internal error */ if (mbedtls_md(md_info, child->tbs.p, child->tbs.len, hash) != 0) { return -1; } #else psa_algorithm_t hash_alg = mbedtls_hash_info_psa_from_md(child->sig_md); psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; status = psa_hash_compute(hash_alg, child->tbs.p, child->tbs.len, hash, sizeof(hash), &hash_len); if (status != PSA_SUCCESS) { return MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED; } #endif /* MBEDTLS_USE_PSA_CRYPTO */ /* 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, hash_len, 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, hash_len, 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 (need_ca_bit && mbedtls_x509_crt_check_key_usage(parent, MBEDTLS_X509_KU_KEY_CERT_SIGN) != 0) { return -1; } 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_ERR_ERROR_CORRUPTION_DETECTED; mbedtls_x509_crt *parent, *fallback_parent; int signature_is_good = 0, 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; } *r_parent = parent; *r_signature_is_good = signature_is_good; break; } if (parent == NULL) { *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_ERR_ERROR_CORRUPTION_DETECTED; 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 -> intermediate CA -> trusted root * - if relevant: EE untrusted * - if relevant: EE -> intermediate, untrusted * with the aspect under test checked at each relevant level (EE, int, root). * For some aspects longer chains are required, but usually length 2 is * enough (but length 1 is not in general). * * Arguments: * - [in] crt: the cert list EE, C1, ..., Cn * - [in] trust_ca: the trusted list R1, ..., Rp * - [in] ca_crl, profile: as in verify_with_profile() * - [out] ver_chain: the built and verified chain * Only valid when return value is 0, may contain garbage otherwise! * Restart note: need not be the same when calling again to resume. * - [in-out] rs_ctx: context for restarting operations * * Return value: * - non-zero if the chain could not be fully built and examined * - 0 is the chain was successfully built and examined, * even if it was found to be invalid */ static int x509_crt_verify_chain( mbedtls_x509_crt *crt, mbedtls_x509_crt *trust_ca, mbedtls_x509_crl *ca_crl, mbedtls_x509_crt_ca_cb_t f_ca_cb, void *p_ca_cb, 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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 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; mbedtls_x509_crt *cur_trust_ca = NULL; #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 /* Obtain list of potential trusted signers from CA callback, * or use statically provided list. */ #if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK) if (f_ca_cb != NULL) { mbedtls_x509_crt_free(ver_chain->trust_ca_cb_result); mbedtls_free(ver_chain->trust_ca_cb_result); ver_chain->trust_ca_cb_result = NULL; ret = f_ca_cb(p_ca_cb, child, &ver_chain->trust_ca_cb_result); if (ret != 0) { return MBEDTLS_ERR_X509_FATAL_ERROR; } cur_trust_ca = ver_chain->trust_ca_cb_result; } else #endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */ { ((void) f_ca_cb); ((void) p_ca_cb); cur_trust_ca = trust_ca; } /* Look for a parent in trusted CAs or up the chain */ ret = x509_crt_find_parent(child, cur_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; } /* * Check for SAN match, see RFC 5280 Section 4.2.1.6 */ static int x509_crt_check_san(const mbedtls_x509_buf *name, const char *cn, size_t cn_len) { const unsigned char san_type = (unsigned char) name->tag & MBEDTLS_ASN1_TAG_VALUE_MASK; /* dNSName */ if (san_type == MBEDTLS_X509_SAN_DNS_NAME) { return x509_crt_check_cn(name, cn, cn_len); } /* (We may handle other types here later.) */ /* Unrecognized type */ 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_san(&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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 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, 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 * * The parameters pairs `trust_ca`, `ca_crl` and `f_ca_cb`, `p_ca_cb` * are mutually exclusive: If `f_ca_cb != NULL`, it will be used by the * verification routine to search for trusted signers, and CRLs will * be disabled. Otherwise, `trust_ca` will be used as the static list * of trusted signers, and `ca_crl` will be use as the static list * of CRLs. */ static int x509_crt_verify_restartable_ca_cb(mbedtls_x509_crt *crt, mbedtls_x509_crt *trust_ca, mbedtls_x509_crl *ca_crl, mbedtls_x509_crt_ca_cb_t f_ca_cb, void *p_ca_cb, 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_ERR_ERROR_CORRUPTION_DETECTED; 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, f_ca_cb, p_ca_cb, 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_X509_TRUSTED_CERTIFICATE_CALLBACK) mbedtls_x509_crt_free(ver_chain.trust_ca_cb_result); mbedtls_free(ver_chain.trust_ca_cb_result); ver_chain.trust_ca_cb_result = NULL; #endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */ #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; } /* * 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 x509_crt_verify_restartable_ca_cb(crt, trust_ca, ca_crl, NULL, NULL, &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 x509_crt_verify_restartable_ca_cb(crt, trust_ca, ca_crl, NULL, NULL, profile, cn, flags, f_vrfy, p_vrfy, NULL); } #if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK) /* * Verify the certificate validity (user-chosen profile, CA callback, * not restartable). */ int mbedtls_x509_crt_verify_with_ca_cb(mbedtls_x509_crt *crt, mbedtls_x509_crt_ca_cb_t f_ca_cb, void *p_ca_cb, 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 x509_crt_verify_restartable_ca_cb(crt, NULL, NULL, f_ca_cb, p_ca_cb, profile, cn, flags, f_vrfy, p_vrfy, NULL); } #endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */ 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) { return x509_crt_verify_restartable_ca_cb(crt, trust_ca, ca_crl, NULL, NULL, profile, cn, flags, f_vrfy, p_vrfy, rs_ctx); } /* * 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; while (cert_cur != NULL) { mbedtls_pk_free(&cert_cur->pk); #if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT) mbedtls_free(cert_cur->sig_opts); #endif mbedtls_asn1_free_named_data_list_shallow(cert_cur->issuer.next); mbedtls_asn1_free_named_data_list_shallow(cert_cur->subject.next); mbedtls_asn1_sequence_free(cert_cur->ext_key_usage.next); mbedtls_asn1_sequence_free(cert_cur->subject_alt_names.next); mbedtls_asn1_sequence_free(cert_cur->certificate_policies.next); if (cert_cur->raw.p != NULL && cert_cur->own_buffer) { mbedtls_platform_zeroize(cert_cur->raw.p, cert_cur->raw.len); mbedtls_free(cert_cur->raw.p); } cert_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); } } } #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 */