/* * X.509 Certificate Revocation List (CRL) parsing * * Copyright The Mbed TLS Contributors * SPDX-License-Identifier: Apache-2.0 * * Licensed under the Apache License, Version 2.0 (the "License"); you may * not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /* * The ITU-T X.509 standard defines a certificate format for PKI. * * http://www.ietf.org/rfc/rfc5280.txt (Certificates and CRLs) * http://www.ietf.org/rfc/rfc3279.txt (Alg IDs for CRLs) * http://www.ietf.org/rfc/rfc2986.txt (CSRs, aka PKCS#10) * * http://www.itu.int/ITU-T/studygroups/com17/languages/X.680-0207.pdf * http://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf */ #include "common.h" #if defined(MBEDTLS_X509_CRL_PARSE_C) #include "mbedtls/x509_crl.h" #include "mbedtls/error.h" #include "mbedtls/oid.h" #include "mbedtls/platform_util.h" #include #if defined(MBEDTLS_PEM_PARSE_C) #include "mbedtls/pem.h" #endif #include "mbedtls/platform.h" #if defined(MBEDTLS_HAVE_TIME) #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32) #include #else #include #endif #endif #if defined(MBEDTLS_FS_IO) || defined(EFIX64) || defined(EFI32) #include #endif /* * Version ::= INTEGER { v1(0), v2(1) } */ static int x509_crl_get_version(unsigned char **p, const unsigned char *end, int *ver) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; if ((ret = mbedtls_asn1_get_int(p, end, ver)) != 0) { if (ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG) { *ver = 0; return 0; } return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_VERSION, ret); } return 0; } /* * X.509 CRL v2 extensions * * We currently don't parse any extension's content, but we do check that the * list of extensions is well-formed and abort on critical extensions (that * are unsupported as we don't support any extension so far) */ static int x509_get_crl_ext(unsigned char **p, const unsigned char *end, mbedtls_x509_buf *ext) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; if (*p == end) { return 0; } /* * crlExtensions [0] EXPLICIT Extensions OPTIONAL * -- if present, version MUST be v2 */ if ((ret = mbedtls_x509_get_ext(p, end, ext, 0)) != 0) { return ret; } end = ext->p + ext->len; while (*p < end) { /* * Extension ::= SEQUENCE { * extnID OBJECT IDENTIFIER, * critical BOOLEAN DEFAULT FALSE, * extnValue OCTET STRING } */ int is_critical = 0; const unsigned char *end_ext_data; size_t len; /* Get enclosing sequence tag */ if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret); } end_ext_data = *p + len; /* Get OID (currently ignored) */ if ((ret = mbedtls_asn1_get_tag(p, end_ext_data, &len, MBEDTLS_ASN1_OID)) != 0) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret); } *p += len; /* Get optional critical */ if ((ret = mbedtls_asn1_get_bool(p, end_ext_data, &is_critical)) != 0 && (ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG)) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret); } /* Data should be octet string type */ if ((ret = mbedtls_asn1_get_tag(p, end_ext_data, &len, MBEDTLS_ASN1_OCTET_STRING)) != 0) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret); } /* Ignore data so far and just check its length */ *p += len; if (*p != end_ext_data) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, MBEDTLS_ERR_ASN1_LENGTH_MISMATCH); } /* Abort on (unsupported) critical extensions */ if (is_critical) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, MBEDTLS_ERR_ASN1_UNEXPECTED_TAG); } } if (*p != end) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, MBEDTLS_ERR_ASN1_LENGTH_MISMATCH); } return 0; } /* * X.509 CRL v2 entry extensions (no extensions parsed yet.) */ static int x509_get_crl_entry_ext(unsigned char **p, const unsigned char *end, mbedtls_x509_buf *ext) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t len = 0; /* OPTIONAL */ if (end <= *p) { return 0; } ext->tag = **p; ext->p = *p; /* * Get CRL-entry extension sequence header * crlEntryExtensions Extensions OPTIONAL -- if present, MUST be v2 */ if ((ret = mbedtls_asn1_get_tag(p, end, &ext->len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) { if (ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG) { ext->p = NULL; return 0; } return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret); } end = *p + ext->len; if (end != *p + ext->len) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, MBEDTLS_ERR_ASN1_LENGTH_MISMATCH); } while (*p < end) { if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret); } *p += len; } if (*p != end) { return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, MBEDTLS_ERR_ASN1_LENGTH_MISMATCH); } return 0; } /* * X.509 CRL Entries */ static int x509_get_entries(unsigned char **p, const unsigned char *end, mbedtls_x509_crl_entry *entry) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t entry_len; mbedtls_x509_crl_entry *cur_entry = entry; if (*p == end) { return 0; } if ((ret = mbedtls_asn1_get_tag(p, end, &entry_len, MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED)) != 0) { if (ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG) { return 0; } return ret; } end = *p + entry_len; while (*p < end) { size_t len2; const unsigned char *end2; cur_entry->raw.tag = **p; if ((ret = mbedtls_asn1_get_tag(p, end, &len2, MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED)) != 0) { return ret; } cur_entry->raw.p = *p; cur_entry->raw.len = len2; end2 = *p + len2; if ((ret = mbedtls_x509_get_serial(p, end2, &cur_entry->serial)) != 0) { return ret; } if ((ret = mbedtls_x509_get_time(p, end2, &cur_entry->revocation_date)) != 0) { return ret; } if ((ret = x509_get_crl_entry_ext(p, end2, &cur_entry->entry_ext)) != 0) { return ret; } if (*p < end) { cur_entry->next = mbedtls_calloc(1, sizeof(mbedtls_x509_crl_entry)); if (cur_entry->next == NULL) { return MBEDTLS_ERR_X509_ALLOC_FAILED; } cur_entry = cur_entry->next; } } return 0; } /* * Parse one CRLs in DER format and append it to the chained list */ int mbedtls_x509_crl_parse_der(mbedtls_x509_crl *chain, const unsigned char *buf, size_t buflen) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t len; unsigned char *p = NULL, *end = NULL; mbedtls_x509_buf sig_params1, sig_params2, sig_oid2; mbedtls_x509_crl *crl = chain; /* * Check for valid input */ if (crl == NULL || buf == NULL) { return MBEDTLS_ERR_X509_BAD_INPUT_DATA; } memset(&sig_params1, 0, sizeof(mbedtls_x509_buf)); memset(&sig_params2, 0, sizeof(mbedtls_x509_buf)); memset(&sig_oid2, 0, sizeof(mbedtls_x509_buf)); /* * Add new CRL on the end of the chain if needed. */ while (crl->version != 0 && crl->next != NULL) { crl = crl->next; } if (crl->version != 0 && crl->next == NULL) { crl->next = mbedtls_calloc(1, sizeof(mbedtls_x509_crl)); if (crl->next == NULL) { mbedtls_x509_crl_free(crl); return MBEDTLS_ERR_X509_ALLOC_FAILED; } mbedtls_x509_crl_init(crl->next); crl = crl->next; } /* * Copy raw DER-encoded CRL */ if (buflen == 0) { return MBEDTLS_ERR_X509_INVALID_FORMAT; } p = mbedtls_calloc(1, buflen); if (p == NULL) { return MBEDTLS_ERR_X509_ALLOC_FAILED; } memcpy(p, buf, buflen); crl->raw.p = p; crl->raw.len = buflen; end = p + buflen; /* * CertificateList ::= SEQUENCE { * tbsCertList TBSCertList, * signatureAlgorithm AlgorithmIdentifier, * signatureValue BIT STRING } */ if ((ret = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) { mbedtls_x509_crl_free(crl); return MBEDTLS_ERR_X509_INVALID_FORMAT; } if (len != (size_t) (end - p)) { mbedtls_x509_crl_free(crl); return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, MBEDTLS_ERR_ASN1_LENGTH_MISMATCH); } /* * TBSCertList ::= SEQUENCE { */ crl->tbs.p = p; if ((ret = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) { mbedtls_x509_crl_free(crl); return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, ret); } end = p + len; crl->tbs.len = end - crl->tbs.p; /* * Version ::= INTEGER OPTIONAL { v1(0), v2(1) } * -- if present, MUST be v2 * * signature AlgorithmIdentifier */ if ((ret = x509_crl_get_version(&p, end, &crl->version)) != 0 || (ret = mbedtls_x509_get_alg(&p, end, &crl->sig_oid, &sig_params1)) != 0) { mbedtls_x509_crl_free(crl); return ret; } if (crl->version < 0 || crl->version > 1) { mbedtls_x509_crl_free(crl); return MBEDTLS_ERR_X509_UNKNOWN_VERSION; } crl->version++; if ((ret = mbedtls_x509_get_sig_alg(&crl->sig_oid, &sig_params1, &crl->sig_md, &crl->sig_pk, &crl->sig_opts)) != 0) { mbedtls_x509_crl_free(crl); return MBEDTLS_ERR_X509_UNKNOWN_SIG_ALG; } /* * issuer Name */ crl->issuer_raw.p = p; if ((ret = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) { mbedtls_x509_crl_free(crl); return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, ret); } if ((ret = mbedtls_x509_get_name(&p, p + len, &crl->issuer)) != 0) { mbedtls_x509_crl_free(crl); return ret; } crl->issuer_raw.len = p - crl->issuer_raw.p; /* * thisUpdate Time * nextUpdate Time OPTIONAL */ if ((ret = mbedtls_x509_get_time(&p, end, &crl->this_update)) != 0) { mbedtls_x509_crl_free(crl); return ret; } if ((ret = mbedtls_x509_get_time(&p, end, &crl->next_update)) != 0) { if (ret != (MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_DATE, MBEDTLS_ERR_ASN1_UNEXPECTED_TAG)) && ret != (MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_DATE, MBEDTLS_ERR_ASN1_OUT_OF_DATA))) { mbedtls_x509_crl_free(crl); return ret; } } /* * revokedCertificates SEQUENCE OF SEQUENCE { * userCertificate CertificateSerialNumber, * revocationDate Time, * crlEntryExtensions Extensions OPTIONAL * -- if present, MUST be v2 * } OPTIONAL */ if ((ret = x509_get_entries(&p, end, &crl->entry)) != 0) { mbedtls_x509_crl_free(crl); return ret; } /* * crlExtensions EXPLICIT Extensions OPTIONAL * -- if present, MUST be v2 */ if (crl->version == 2) { ret = x509_get_crl_ext(&p, end, &crl->crl_ext); if (ret != 0) { mbedtls_x509_crl_free(crl); return ret; } } if (p != end) { mbedtls_x509_crl_free(crl); return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, MBEDTLS_ERR_ASN1_LENGTH_MISMATCH); } end = crl->raw.p + crl->raw.len; /* * signatureAlgorithm AlgorithmIdentifier, * signatureValue BIT STRING */ if ((ret = mbedtls_x509_get_alg(&p, end, &sig_oid2, &sig_params2)) != 0) { mbedtls_x509_crl_free(crl); return ret; } if (crl->sig_oid.len != sig_oid2.len || memcmp(crl->sig_oid.p, sig_oid2.p, crl->sig_oid.len) != 0 || sig_params1.len != sig_params2.len || (sig_params1.len != 0 && memcmp(sig_params1.p, sig_params2.p, sig_params1.len) != 0)) { mbedtls_x509_crl_free(crl); return MBEDTLS_ERR_X509_SIG_MISMATCH; } if ((ret = mbedtls_x509_get_sig(&p, end, &crl->sig)) != 0) { mbedtls_x509_crl_free(crl); return ret; } if (p != end) { mbedtls_x509_crl_free(crl); return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, MBEDTLS_ERR_ASN1_LENGTH_MISMATCH); } return 0; } /* * Parse one or more CRLs and add them to the chained list */ int mbedtls_x509_crl_parse(mbedtls_x509_crl *chain, const unsigned char *buf, size_t buflen) { #if defined(MBEDTLS_PEM_PARSE_C) int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t use_len = 0; mbedtls_pem_context pem; int is_pem = 0; if (chain == NULL || buf == NULL) { return MBEDTLS_ERR_X509_BAD_INPUT_DATA; } do { mbedtls_pem_init(&pem); // Avoid calling mbedtls_pem_read_buffer() on non-null-terminated // string if (buflen == 0 || buf[buflen - 1] != '\0') { ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT; } else { ret = mbedtls_pem_read_buffer(&pem, "-----BEGIN X509 CRL-----", "-----END X509 CRL-----", buf, NULL, 0, &use_len); } if (ret == 0) { /* * Was PEM encoded */ is_pem = 1; buflen -= use_len; buf += use_len; if ((ret = mbedtls_x509_crl_parse_der(chain, pem.buf, pem.buflen)) != 0) { mbedtls_pem_free(&pem); return ret; } } else if (is_pem) { mbedtls_pem_free(&pem); return ret; } mbedtls_pem_free(&pem); } /* In the PEM case, buflen is 1 at the end, for the terminated NULL byte. * And a valid CRL cannot be less than 1 byte anyway. */ while (is_pem && buflen > 1); if (is_pem) { return 0; } else #endif /* MBEDTLS_PEM_PARSE_C */ return mbedtls_x509_crl_parse_der(chain, buf, buflen); } #if defined(MBEDTLS_FS_IO) /* * Load one or more CRLs and add them to the chained list */ int mbedtls_x509_crl_parse_file(mbedtls_x509_crl *chain, const char *path) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t n; unsigned char *buf; if ((ret = mbedtls_pk_load_file(path, &buf, &n)) != 0) { return ret; } ret = mbedtls_x509_crl_parse(chain, buf, n); mbedtls_platform_zeroize(buf, n); mbedtls_free(buf); return ret; } #endif /* MBEDTLS_FS_IO */ #if !defined(MBEDTLS_X509_REMOVE_INFO) /* * Return an informational string about the certificate. */ #define BEFORE_COLON 14 #define BC "14" /* * Return an informational string about the CRL. */ int mbedtls_x509_crl_info(char *buf, size_t size, const char *prefix, const mbedtls_x509_crl *crl) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t n; char *p; const mbedtls_x509_crl_entry *entry; p = buf; n = size; ret = mbedtls_snprintf(p, n, "%sCRL version : %d", prefix, crl->version); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_snprintf(p, n, "\n%sissuer name : ", prefix); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_x509_dn_gets(p, n, &crl->issuer); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_snprintf(p, n, "\n%sthis update : " \ "%04d-%02d-%02d %02d:%02d:%02d", prefix, crl->this_update.year, crl->this_update.mon, crl->this_update.day, crl->this_update.hour, crl->this_update.min, crl->this_update.sec); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_snprintf(p, n, "\n%snext update : " \ "%04d-%02d-%02d %02d:%02d:%02d", prefix, crl->next_update.year, crl->next_update.mon, crl->next_update.day, crl->next_update.hour, crl->next_update.min, crl->next_update.sec); MBEDTLS_X509_SAFE_SNPRINTF; entry = &crl->entry; ret = mbedtls_snprintf(p, n, "\n%sRevoked certificates:", prefix); MBEDTLS_X509_SAFE_SNPRINTF; while (entry != NULL && entry->raw.len != 0) { ret = mbedtls_snprintf(p, n, "\n%sserial number: ", prefix); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_x509_serial_gets(p, n, &entry->serial); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_snprintf(p, n, " revocation date: " \ "%04d-%02d-%02d %02d:%02d:%02d", entry->revocation_date.year, entry->revocation_date.mon, entry->revocation_date.day, entry->revocation_date.hour, entry->revocation_date.min, entry->revocation_date.sec); MBEDTLS_X509_SAFE_SNPRINTF; entry = entry->next; } ret = mbedtls_snprintf(p, n, "\n%ssigned using : ", prefix); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_x509_sig_alg_gets(p, n, &crl->sig_oid, crl->sig_pk, crl->sig_md, crl->sig_opts); MBEDTLS_X509_SAFE_SNPRINTF; ret = mbedtls_snprintf(p, n, "\n"); MBEDTLS_X509_SAFE_SNPRINTF; return (int) (size - n); } #endif /* MBEDTLS_X509_REMOVE_INFO */ /* * Initialize a CRL chain */ void mbedtls_x509_crl_init(mbedtls_x509_crl *crl) { memset(crl, 0, sizeof(mbedtls_x509_crl)); } /* * Unallocate all CRL data */ void mbedtls_x509_crl_free(mbedtls_x509_crl *crl) { mbedtls_x509_crl *crl_cur = crl; mbedtls_x509_crl *crl_prv; mbedtls_x509_crl_entry *entry_cur; mbedtls_x509_crl_entry *entry_prv; while (crl_cur != NULL) { #if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT) mbedtls_free(crl_cur->sig_opts); #endif mbedtls_asn1_free_named_data_list_shallow(crl_cur->issuer.next); entry_cur = crl_cur->entry.next; while (entry_cur != NULL) { entry_prv = entry_cur; entry_cur = entry_cur->next; mbedtls_platform_zeroize(entry_prv, sizeof(mbedtls_x509_crl_entry)); mbedtls_free(entry_prv); } if (crl_cur->raw.p != NULL) { mbedtls_platform_zeroize(crl_cur->raw.p, crl_cur->raw.len); mbedtls_free(crl_cur->raw.p); } crl_prv = crl_cur; crl_cur = crl_cur->next; mbedtls_platform_zeroize(crl_prv, sizeof(mbedtls_x509_crl)); if (crl_prv != crl) { mbedtls_free(crl_prv); } } } #endif /* MBEDTLS_X509_CRL_PARSE_C */