diff options
Diffstat (limited to 'library/x509_csr.c')
| -rw-r--r-- | library/x509_csr.c | 639 |
1 files changed, 639 insertions, 0 deletions
diff --git a/library/x509_csr.c b/library/x509_csr.c new file mode 100644 index 00000000000..813d64466cc --- /dev/null +++ b/library/x509_csr.c @@ -0,0 +1,639 @@ +/* + * X.509 Certificate Signing Request (CSR) parsing + * + * Copyright The Mbed TLS Contributors + * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later + */ +/* + * 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_CSR_PARSE_C) + +#include "mbedtls/x509_csr.h" +#include "x509_internal.h" +#include "mbedtls/error.h" +#include "mbedtls/oid.h" +#include "mbedtls/platform_util.h" + +#include <string.h> + +#if defined(MBEDTLS_PEM_PARSE_C) +#include "mbedtls/pem.h" +#endif + +#include "mbedtls/platform.h" + +#if defined(MBEDTLS_FS_IO) || defined(EFIX64) || defined(EFI32) +#include <stdio.h> +#endif + +/* + * Version ::= INTEGER { v1(0) } + */ +static int x509_csr_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; +} + +/* + * Parse CSR extension requests in DER format + */ +static int x509_csr_parse_extensions(mbedtls_x509_csr *csr, + unsigned char **p, const unsigned char *end, + mbedtls_x509_csr_ext_cb_t cb, + void *p_ctx) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + size_t len; + unsigned char *end_ext_data, *end_ext_octet; + + while (*p < end) { + mbedtls_x509_buf extn_oid = { 0, 0, NULL }; + int is_critical = 0; /* DEFAULT FALSE */ + int ext_type = 0; + + /* Read 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 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); + } + + 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 and skip unsupported 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, csr, &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 ((csr->ext_types & ext_type) != 0) { + return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, + MBEDTLS_ERR_ASN1_INVALID_DATA); + } + + csr->ext_types |= ext_type; + + switch (ext_type) { + case MBEDTLS_X509_EXT_KEY_USAGE: + /* Parse key usage */ + if ((ret = mbedtls_x509_get_key_usage(p, end_ext_data, + &csr->key_usage)) != 0) { + return ret; + } + break; + + case MBEDTLS_X509_EXT_SUBJECT_ALT_NAME: + /* Parse subject alt name */ + if ((ret = mbedtls_x509_get_subject_alt_name(p, end_ext_data, + &csr->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_data, + &csr->ns_cert_type)) != 0) { + 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 CSR attributes in DER format + */ +static int x509_csr_parse_attributes(mbedtls_x509_csr *csr, + const unsigned char *start, const unsigned char *end, + mbedtls_x509_csr_ext_cb_t cb, + void *p_ctx) +{ + int ret; + size_t len; + unsigned char *end_attr_data; + unsigned char **p = (unsigned char **) &start; + + while (*p < end) { + mbedtls_x509_buf attr_oid = { 0, 0, NULL }; + + 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_attr_data = *p + len; + + /* Get attribute ID */ + if ((ret = mbedtls_asn1_get_tag(p, end_attr_data, &attr_oid.len, + MBEDTLS_ASN1_OID)) != 0) { + return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret); + } + + attr_oid.tag = MBEDTLS_ASN1_OID; + attr_oid.p = *p; + *p += attr_oid.len; + + /* Check that this is an extension-request attribute */ + if (MBEDTLS_OID_CMP(MBEDTLS_OID_PKCS9_CSR_EXT_REQ, &attr_oid) == 0) { + if ((ret = mbedtls_asn1_get_tag(p, end, &len, + MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SET)) != 0) { + return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret); + } + + 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 ((ret = x509_csr_parse_extensions(csr, p, *p + len, cb, p_ctx)) != 0) { + return ret; + } + + if (*p != end_attr_data) { + return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH); + } + } + + *p = end_attr_data; + } + + if (*p != end) { + return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH); + } + + return 0; +} + +/* + * Parse a CSR in DER format + */ +static int mbedtls_x509_csr_parse_der_internal(mbedtls_x509_csr *csr, + const unsigned char *buf, size_t buflen, + mbedtls_x509_csr_ext_cb_t cb, + void *p_ctx) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + size_t len; + unsigned char *p, *end; + mbedtls_x509_buf sig_params; + + memset(&sig_params, 0, sizeof(mbedtls_x509_buf)); + + /* + * Check for valid input + */ + if (csr == NULL || buf == NULL || buflen == 0) { + return MBEDTLS_ERR_X509_BAD_INPUT_DATA; + } + + mbedtls_x509_csr_init(csr); + + /* + * first copy the raw DER data + */ + p = mbedtls_calloc(1, len = buflen); + + if (p == NULL) { + return MBEDTLS_ERR_X509_ALLOC_FAILED; + } + + memcpy(p, buf, buflen); + + csr->raw.p = p; + csr->raw.len = len; + end = p + len; + + /* + * CertificationRequest ::= SEQUENCE { + * certificationRequestInfo CertificationRequestInfo, + * signatureAlgorithm AlgorithmIdentifier, + * signature BIT STRING + * } + */ + if ((ret = mbedtls_asn1_get_tag(&p, end, &len, + MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) { + mbedtls_x509_csr_free(csr); + return MBEDTLS_ERR_X509_INVALID_FORMAT; + } + + if (len != (size_t) (end - p)) { + mbedtls_x509_csr_free(csr); + return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH); + } + + /* + * CertificationRequestInfo ::= SEQUENCE { + */ + csr->cri.p = p; + + if ((ret = mbedtls_asn1_get_tag(&p, end, &len, + MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) { + mbedtls_x509_csr_free(csr); + return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, ret); + } + + end = p + len; + csr->cri.len = (size_t) (end - csr->cri.p); + + /* + * Version ::= INTEGER { v1(0) } + */ + if ((ret = x509_csr_get_version(&p, end, &csr->version)) != 0) { + mbedtls_x509_csr_free(csr); + return ret; + } + + if (csr->version != 0) { + mbedtls_x509_csr_free(csr); + return MBEDTLS_ERR_X509_UNKNOWN_VERSION; + } + + csr->version++; + + /* + * subject Name + */ + csr->subject_raw.p = p; + + if ((ret = mbedtls_asn1_get_tag(&p, end, &len, + MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) { + mbedtls_x509_csr_free(csr); + return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, ret); + } + + if ((ret = mbedtls_x509_get_name(&p, p + len, &csr->subject)) != 0) { + mbedtls_x509_csr_free(csr); + return ret; + } + + csr->subject_raw.len = (size_t) (p - csr->subject_raw.p); + + /* + * subjectPKInfo SubjectPublicKeyInfo + */ + if ((ret = mbedtls_pk_parse_subpubkey(&p, end, &csr->pk)) != 0) { + mbedtls_x509_csr_free(csr); + return ret; + } + + /* + * attributes [0] Attributes + * + * The list of possible attributes is open-ended, though RFC 2985 + * (PKCS#9) defines a few in section 5.4. We currently don't support any, + * so we just ignore them. This is a safe thing to do as the worst thing + * that could happen is that we issue a certificate that does not match + * the requester's expectations - this cannot cause a violation of our + * signature policies. + */ + if ((ret = mbedtls_asn1_get_tag(&p, end, &len, + MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_CONTEXT_SPECIFIC)) != + 0) { + mbedtls_x509_csr_free(csr); + return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, ret); + } + + if ((ret = x509_csr_parse_attributes(csr, p, p + len, cb, p_ctx)) != 0) { + mbedtls_x509_csr_free(csr); + return ret; + } + + p += len; + + end = csr->raw.p + csr->raw.len; + + /* + * signatureAlgorithm AlgorithmIdentifier, + * signature BIT STRING + */ + if ((ret = mbedtls_x509_get_alg(&p, end, &csr->sig_oid, &sig_params)) != 0) { + mbedtls_x509_csr_free(csr); + return ret; + } + + if ((ret = mbedtls_x509_get_sig_alg(&csr->sig_oid, &sig_params, + &csr->sig_md, &csr->sig_pk, + &csr->sig_opts)) != 0) { + mbedtls_x509_csr_free(csr); + return MBEDTLS_ERR_X509_UNKNOWN_SIG_ALG; + } + + if ((ret = mbedtls_x509_get_sig(&p, end, &csr->sig)) != 0) { + mbedtls_x509_csr_free(csr); + return ret; + } + + if (p != end) { + mbedtls_x509_csr_free(csr); + return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH); + } + + return 0; +} + +/* + * Parse a CSR in DER format + */ +int mbedtls_x509_csr_parse_der(mbedtls_x509_csr *csr, + const unsigned char *buf, size_t buflen) +{ + return mbedtls_x509_csr_parse_der_internal(csr, buf, buflen, NULL, NULL); +} + +/* + * Parse a CSR in DER format with callback for unknown extensions + */ +int mbedtls_x509_csr_parse_der_with_ext_cb(mbedtls_x509_csr *csr, + const unsigned char *buf, size_t buflen, + mbedtls_x509_csr_ext_cb_t cb, + void *p_ctx) +{ + return mbedtls_x509_csr_parse_der_internal(csr, buf, buflen, cb, p_ctx); +} + +/* + * Parse a CSR, allowing for PEM or raw DER encoding + */ +int mbedtls_x509_csr_parse(mbedtls_x509_csr *csr, const unsigned char *buf, size_t buflen) +{ +#if defined(MBEDTLS_PEM_PARSE_C) + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + size_t use_len; + mbedtls_pem_context pem; +#endif + + /* + * Check for valid input + */ + if (csr == NULL || buf == NULL || buflen == 0) { + return MBEDTLS_ERR_X509_BAD_INPUT_DATA; + } + +#if defined(MBEDTLS_PEM_PARSE_C) + /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */ + if (buf[buflen - 1] == '\0') { + mbedtls_pem_init(&pem); + ret = mbedtls_pem_read_buffer(&pem, + "-----BEGIN CERTIFICATE REQUEST-----", + "-----END CERTIFICATE REQUEST-----", + buf, NULL, 0, &use_len); + if (ret == MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT) { + ret = mbedtls_pem_read_buffer(&pem, + "-----BEGIN NEW CERTIFICATE REQUEST-----", + "-----END NEW CERTIFICATE REQUEST-----", + buf, NULL, 0, &use_len); + } + + if (ret == 0) { + /* + * Was PEM encoded, parse the result + */ + ret = mbedtls_x509_csr_parse_der(csr, pem.buf, pem.buflen); + } + + mbedtls_pem_free(&pem); + if (ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT) { + return ret; + } + } +#endif /* MBEDTLS_PEM_PARSE_C */ + return mbedtls_x509_csr_parse_der(csr, buf, buflen); +} + +#if defined(MBEDTLS_FS_IO) +/* + * Load a CSR into the structure + */ +int mbedtls_x509_csr_parse_file(mbedtls_x509_csr *csr, 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_csr_parse(csr, buf, n); + + mbedtls_zeroize_and_free(buf, n); + + return ret; +} +#endif /* MBEDTLS_FS_IO */ + +#if !defined(MBEDTLS_X509_REMOVE_INFO) +#define BEFORE_COLON 14 +#define BC "14" +/* + * Return an informational string about the CSR. + */ +int mbedtls_x509_csr_info(char *buf, size_t size, const char *prefix, + const mbedtls_x509_csr *csr) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + size_t n; + char *p; + char key_size_str[BEFORE_COLON]; + + p = buf; + n = size; + + ret = mbedtls_snprintf(p, n, "%sCSR version : %d", + prefix, csr->version); + MBEDTLS_X509_SAFE_SNPRINTF; + + ret = mbedtls_snprintf(p, n, "\n%ssubject name : ", prefix); + MBEDTLS_X509_SAFE_SNPRINTF; + ret = mbedtls_x509_dn_gets(p, n, &csr->subject); + 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, &csr->sig_oid, csr->sig_pk, csr->sig_md, + csr->sig_opts); + MBEDTLS_X509_SAFE_SNPRINTF; + + if ((ret = mbedtls_x509_key_size_helper(key_size_str, BEFORE_COLON, + mbedtls_pk_get_name(&csr->pk))) != 0) { + return ret; + } + + ret = mbedtls_snprintf(p, n, "\n%s%-" BC "s: %d bits\n", prefix, key_size_str, + (int) mbedtls_pk_get_bitlen(&csr->pk)); + MBEDTLS_X509_SAFE_SNPRINTF; + + /* + * Optional extensions + */ + + if (csr->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, + &csr->subject_alt_names, + prefix)) != 0) { + return ret; + } + } + + if (csr->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, csr->ns_cert_type)) != 0) { + return ret; + } + } + + if (csr->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, csr->key_usage)) != 0) { + return ret; + } + } + + if (csr->ext_types != 0) { + ret = mbedtls_snprintf(p, n, "\n"); + MBEDTLS_X509_SAFE_SNPRINTF; + } + + return (int) (size - n); +} +#endif /* MBEDTLS_X509_REMOVE_INFO */ + +/* + * Initialize a CSR + */ +void mbedtls_x509_csr_init(mbedtls_x509_csr *csr) +{ + memset(csr, 0, sizeof(mbedtls_x509_csr)); +} + +/* + * Unallocate all CSR data + */ +void mbedtls_x509_csr_free(mbedtls_x509_csr *csr) +{ + if (csr == NULL) { + return; + } + + mbedtls_pk_free(&csr->pk); + +#if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT) + mbedtls_free(csr->sig_opts); +#endif + + mbedtls_asn1_free_named_data_list_shallow(csr->subject.next); + mbedtls_asn1_sequence_free(csr->subject_alt_names.next); + + if (csr->raw.p != NULL) { + mbedtls_zeroize_and_free(csr->raw.p, csr->raw.len); + } + + mbedtls_platform_zeroize(csr, sizeof(mbedtls_x509_csr)); +} + +#endif /* MBEDTLS_X509_CSR_PARSE_C */ |