/* * X.509 base functions for creating certificates / CSRs * * 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. */ #include "common.h" #if defined(MBEDTLS_X509_CREATE_C) #include "mbedtls/x509.h" #include "mbedtls/asn1write.h" #include "mbedtls/error.h" #include "mbedtls/oid.h" #include /* Structure linking OIDs for X.509 DN AttributeTypes to their * string representations and default string encodings used by Mbed TLS. */ typedef struct { const char *name; /* String representation of AttributeType, e.g. * "CN" or "emailAddress". */ size_t name_len; /* Length of 'name', without trailing 0 byte. */ const char *oid; /* String representation of OID of AttributeType, * as per RFC 5280, Appendix A.1. */ int default_tag; /* The default character encoding used for the * given attribute type, e.g. * MBEDTLS_ASN1_UTF8_STRING for UTF-8. */ } x509_attr_descriptor_t; #define ADD_STRLEN(s) s, sizeof(s) - 1 /* X.509 DN attributes from RFC 5280, Appendix A.1. */ static const x509_attr_descriptor_t x509_attrs[] = { { ADD_STRLEN("CN"), MBEDTLS_OID_AT_CN, MBEDTLS_ASN1_UTF8_STRING }, { ADD_STRLEN("commonName"), MBEDTLS_OID_AT_CN, MBEDTLS_ASN1_UTF8_STRING }, { ADD_STRLEN("C"), MBEDTLS_OID_AT_COUNTRY, MBEDTLS_ASN1_PRINTABLE_STRING }, { ADD_STRLEN("countryName"), MBEDTLS_OID_AT_COUNTRY, MBEDTLS_ASN1_PRINTABLE_STRING }, { ADD_STRLEN("O"), MBEDTLS_OID_AT_ORGANIZATION, MBEDTLS_ASN1_UTF8_STRING }, { ADD_STRLEN("organizationName"), MBEDTLS_OID_AT_ORGANIZATION, MBEDTLS_ASN1_UTF8_STRING }, { ADD_STRLEN("L"), MBEDTLS_OID_AT_LOCALITY, MBEDTLS_ASN1_UTF8_STRING }, { ADD_STRLEN("locality"), MBEDTLS_OID_AT_LOCALITY, MBEDTLS_ASN1_UTF8_STRING }, { ADD_STRLEN("R"), MBEDTLS_OID_PKCS9_EMAIL, MBEDTLS_ASN1_IA5_STRING }, { ADD_STRLEN("OU"), MBEDTLS_OID_AT_ORG_UNIT, MBEDTLS_ASN1_UTF8_STRING }, { ADD_STRLEN("organizationalUnitName"), MBEDTLS_OID_AT_ORG_UNIT, MBEDTLS_ASN1_UTF8_STRING }, { ADD_STRLEN("ST"), MBEDTLS_OID_AT_STATE, MBEDTLS_ASN1_UTF8_STRING }, { ADD_STRLEN("stateOrProvinceName"), MBEDTLS_OID_AT_STATE, MBEDTLS_ASN1_UTF8_STRING }, { ADD_STRLEN("emailAddress"), MBEDTLS_OID_PKCS9_EMAIL, MBEDTLS_ASN1_IA5_STRING }, { ADD_STRLEN("serialNumber"), MBEDTLS_OID_AT_SERIAL_NUMBER, MBEDTLS_ASN1_PRINTABLE_STRING }, { ADD_STRLEN("postalAddress"), MBEDTLS_OID_AT_POSTAL_ADDRESS, MBEDTLS_ASN1_PRINTABLE_STRING }, { ADD_STRLEN("postalCode"), MBEDTLS_OID_AT_POSTAL_CODE, MBEDTLS_ASN1_PRINTABLE_STRING }, { ADD_STRLEN("dnQualifier"), MBEDTLS_OID_AT_DN_QUALIFIER, MBEDTLS_ASN1_PRINTABLE_STRING }, { ADD_STRLEN("title"), MBEDTLS_OID_AT_TITLE, MBEDTLS_ASN1_UTF8_STRING }, { ADD_STRLEN("surName"), MBEDTLS_OID_AT_SUR_NAME, MBEDTLS_ASN1_UTF8_STRING }, { ADD_STRLEN("SN"), MBEDTLS_OID_AT_SUR_NAME, MBEDTLS_ASN1_UTF8_STRING }, { ADD_STRLEN("givenName"), MBEDTLS_OID_AT_GIVEN_NAME, MBEDTLS_ASN1_UTF8_STRING }, { ADD_STRLEN("GN"), MBEDTLS_OID_AT_GIVEN_NAME, MBEDTLS_ASN1_UTF8_STRING }, { ADD_STRLEN("initials"), MBEDTLS_OID_AT_INITIALS, MBEDTLS_ASN1_UTF8_STRING }, { ADD_STRLEN("pseudonym"), MBEDTLS_OID_AT_PSEUDONYM, MBEDTLS_ASN1_UTF8_STRING }, { ADD_STRLEN("generationQualifier"), MBEDTLS_OID_AT_GENERATION_QUALIFIER, MBEDTLS_ASN1_UTF8_STRING }, { ADD_STRLEN("domainComponent"), MBEDTLS_OID_DOMAIN_COMPONENT, MBEDTLS_ASN1_IA5_STRING }, { ADD_STRLEN("DC"), MBEDTLS_OID_DOMAIN_COMPONENT, MBEDTLS_ASN1_IA5_STRING }, { NULL, 0, NULL, MBEDTLS_ASN1_NULL } }; static const x509_attr_descriptor_t *x509_attr_descr_from_name(const char *name, size_t name_len) { const x509_attr_descriptor_t *cur; for (cur = x509_attrs; cur->name != NULL; cur++) { if (cur->name_len == name_len && strncmp(cur->name, name, name_len) == 0) { break; } } if (cur->name == NULL) { return NULL; } return cur; } int mbedtls_x509_string_to_names(mbedtls_asn1_named_data **head, const char *name) { int ret = MBEDTLS_ERR_X509_INVALID_NAME; const char *s = name, *c = s; const char *end = s + strlen(s); const char *oid = NULL; const x509_attr_descriptor_t *attr_descr = NULL; int in_tag = 1; char data[MBEDTLS_X509_MAX_DN_NAME_SIZE]; char *d = data; /* Clear existing chain if present */ mbedtls_asn1_free_named_data_list(head); while (c <= end) { if (in_tag && *c == '=') { if ((attr_descr = x509_attr_descr_from_name(s, c - s)) == NULL) { ret = MBEDTLS_ERR_X509_UNKNOWN_OID; goto exit; } oid = attr_descr->oid; s = c + 1; in_tag = 0; d = data; } if (!in_tag && *c == '\\' && c != end) { c++; /* Check for valid escaped characters */ if (c == end || *c != ',') { ret = MBEDTLS_ERR_X509_INVALID_NAME; goto exit; } } else if (!in_tag && (*c == ',' || c == end)) { mbedtls_asn1_named_data *cur = mbedtls_asn1_store_named_data(head, oid, strlen(oid), (unsigned char *) data, d - data); if (cur == NULL) { return MBEDTLS_ERR_X509_ALLOC_FAILED; } // set tagType cur->val.tag = attr_descr->default_tag; while (c < end && *(c + 1) == ' ') { c++; } s = c + 1; in_tag = 1; /* Successfully parsed one name, update ret to success */ ret = 0; } if (!in_tag && s != c + 1) { *(d++) = *c; if (d - data == MBEDTLS_X509_MAX_DN_NAME_SIZE) { ret = MBEDTLS_ERR_X509_INVALID_NAME; goto exit; } } c++; } exit: return ret; } /* The first byte of the value in the mbedtls_asn1_named_data structure is reserved * to store the critical boolean for us */ int mbedtls_x509_set_extension(mbedtls_asn1_named_data **head, const char *oid, size_t oid_len, int critical, const unsigned char *val, size_t val_len) { mbedtls_asn1_named_data *cur; if ((cur = mbedtls_asn1_store_named_data(head, oid, oid_len, NULL, val_len + 1)) == NULL) { return MBEDTLS_ERR_X509_ALLOC_FAILED; } cur->val.p[0] = critical; memcpy(cur->val.p + 1, val, val_len); return 0; } /* * RelativeDistinguishedName ::= * SET OF AttributeTypeAndValue * * AttributeTypeAndValue ::= SEQUENCE { * type AttributeType, * value AttributeValue } * * AttributeType ::= OBJECT IDENTIFIER * * AttributeValue ::= ANY DEFINED BY AttributeType */ static int x509_write_name(unsigned char **p, unsigned char *start, mbedtls_asn1_named_data *cur_name) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t len = 0; const char *oid = (const char *) cur_name->oid.p; size_t oid_len = cur_name->oid.len; const unsigned char *name = cur_name->val.p; size_t name_len = cur_name->val.len; // Write correct string tag and value MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tagged_string(p, start, cur_name->val.tag, (const char *) name, name_len)); // Write OID // MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_oid(p, start, oid, oid_len)); MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len)); MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)); MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len)); MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SET)); return (int) len; } int mbedtls_x509_write_names(unsigned char **p, unsigned char *start, mbedtls_asn1_named_data *first) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t len = 0; mbedtls_asn1_named_data *cur = first; while (cur != NULL) { MBEDTLS_ASN1_CHK_ADD(len, x509_write_name(p, start, cur)); cur = cur->next; } MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len)); MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)); return (int) len; } int mbedtls_x509_write_sig(unsigned char **p, unsigned char *start, const char *oid, size_t oid_len, unsigned char *sig, size_t size, mbedtls_pk_type_t pk_alg) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; int write_null_par; size_t len = 0; if (*p < start || (size_t) (*p - start) < size) { return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL; } len = size; (*p) -= len; memcpy(*p, sig, len); if (*p - start < 1) { return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL; } *--(*p) = 0; len += 1; MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len)); MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_BIT_STRING)); // Write OID // if (pk_alg == MBEDTLS_PK_ECDSA) { /* * The AlgorithmIdentifier's parameters field must be absent for DSA/ECDSA signature * algorithms, see https://www.rfc-editor.org/rfc/rfc5480#page-17 and * https://www.rfc-editor.org/rfc/rfc5758#section-3. */ write_null_par = 0; } else { write_null_par = 1; } MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_algorithm_identifier_ext(p, start, oid, oid_len, 0, write_null_par)); return (int) len; } static int x509_write_extension(unsigned char **p, unsigned char *start, mbedtls_asn1_named_data *ext) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t len = 0; MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_raw_buffer(p, start, ext->val.p + 1, ext->val.len - 1)); MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, ext->val.len - 1)); MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_OCTET_STRING)); if (ext->val.p[0] != 0) { MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_bool(p, start, 1)); } MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_raw_buffer(p, start, ext->oid.p, ext->oid.len)); MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, ext->oid.len)); MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_OID)); MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len)); MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)); return (int) len; } /* * Extension ::= SEQUENCE { * extnID OBJECT IDENTIFIER, * critical BOOLEAN DEFAULT FALSE, * extnValue OCTET STRING * -- contains the DER encoding of an ASN.1 value * -- corresponding to the extension type identified * -- by extnID * } */ int mbedtls_x509_write_extensions(unsigned char **p, unsigned char *start, mbedtls_asn1_named_data *first) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t len = 0; mbedtls_asn1_named_data *cur_ext = first; while (cur_ext != NULL) { MBEDTLS_ASN1_CHK_ADD(len, x509_write_extension(p, start, cur_ext)); cur_ext = cur_ext->next; } return (int) len; } #endif /* MBEDTLS_X509_CREATE_C */