|  | /* | 
|  | *  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 <string.h> | 
|  |  | 
|  | #include "mbedtls/platform.h" | 
|  |  | 
|  | #include "mbedtls/asn1.h" | 
|  |  | 
|  | /* 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. encoded as per | 
|  | * X.690 */ | 
|  | 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; | 
|  | } | 
|  |  | 
|  | static int hex_to_int(char c) | 
|  | { | 
|  | return ('0' <= c && c <= '9') ? (c - '0') : | 
|  | ('a' <= c && c <= 'f') ? (c - 'a' + 10) : | 
|  | ('A' <= c && c <= 'F') ? (c - 'A' + 10) : -1; | 
|  | } | 
|  |  | 
|  | static int hexpair_to_int(const char *hexpair) | 
|  | { | 
|  | int n1 = hex_to_int(*hexpair); | 
|  | int n2 = hex_to_int(*(hexpair + 1)); | 
|  |  | 
|  | if (n1 != -1 && n2 != -1) { | 
|  | return (n1 << 4) | n2; | 
|  | } else { | 
|  | return -1; | 
|  | } | 
|  | } | 
|  |  | 
|  | static int parse_attribute_value_string(const char *s, | 
|  | int len, | 
|  | unsigned char *data, | 
|  | size_t *data_len) | 
|  | { | 
|  | const char *c; | 
|  | const char *end = s + len; | 
|  | unsigned char *d = data; | 
|  | int n; | 
|  |  | 
|  | for (c = s; c < end; c++) { | 
|  | if (*c == '\\') { | 
|  | c++; | 
|  |  | 
|  | /* Check for valid escaped characters as per RFC 4514 Section 3 */ | 
|  | if (c + 1 < end && (n = hexpair_to_int(c)) != -1) { | 
|  | if (n == 0) { | 
|  | return MBEDTLS_ERR_X509_INVALID_NAME; | 
|  | } | 
|  | *(d++) = n; | 
|  | c++; | 
|  | } else if (c < end && strchr(" ,=+<>#;\"\\", *c)) { | 
|  | *(d++) = *c; | 
|  | } else { | 
|  | return MBEDTLS_ERR_X509_INVALID_NAME; | 
|  | } | 
|  | } else { | 
|  | *(d++) = *c; | 
|  | } | 
|  |  | 
|  | if (d - data == MBEDTLS_X509_MAX_DN_NAME_SIZE) { | 
|  | return MBEDTLS_ERR_X509_INVALID_NAME; | 
|  | } | 
|  | } | 
|  | *data_len = d - data; | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int parse_attribute_value_der_encoded(const char *s, | 
|  | int len, | 
|  | unsigned char *data, | 
|  | size_t *data_len, | 
|  | int *tag) | 
|  | { | 
|  | const char *c = s; | 
|  | const char *end = c + len; | 
|  | unsigned char asn1_der_buf[MBEDTLS_X509_MAX_DN_NAME_SIZE]; | 
|  | unsigned char *asn1_der_end; | 
|  | unsigned char *p; | 
|  | unsigned char *d = data; | 
|  | int n; | 
|  |  | 
|  | /* Converting from hexstring to raw binary so we can use asn1parse.c */ | 
|  | if ((len < 5) || (*c != '#')) { | 
|  | return MBEDTLS_ERR_X509_INVALID_NAME; | 
|  | } | 
|  | c++; | 
|  | if ((*tag = hexpair_to_int(c)) == -1) { | 
|  | return MBEDTLS_ERR_X509_INVALID_NAME; | 
|  | } | 
|  | c += 2; | 
|  | p = asn1_der_buf; | 
|  | for (p = asn1_der_buf; c < end; c += 2) { | 
|  | if ((c + 1 >= end) || (n = hexpair_to_int(c)) == -1) { | 
|  | return MBEDTLS_ERR_X509_INVALID_NAME; | 
|  | } | 
|  | if (MBEDTLS_ASN1_IS_STRING_TAG(*tag) && n == 0) { | 
|  | return MBEDTLS_ERR_X509_INVALID_NAME; | 
|  | } | 
|  | *(p++) = n; | 
|  | } | 
|  | asn1_der_end = p; | 
|  |  | 
|  | p = asn1_der_buf; | 
|  | if (mbedtls_asn1_get_len(&p, asn1_der_end, data_len) != 0) { | 
|  | return MBEDTLS_ERR_X509_INVALID_NAME; | 
|  | } | 
|  |  | 
|  | while (p < asn1_der_end) { | 
|  | *(d++) = *(p++); | 
|  | } | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | int mbedtls_x509_string_to_names(mbedtls_asn1_named_data **head, const char *name) | 
|  | { | 
|  | int ret = MBEDTLS_ERR_X509_INVALID_NAME; | 
|  | int parse_ret = 0; | 
|  | const char *s = name, *c = s; | 
|  | const char *end = s + strlen(s); | 
|  | mbedtls_asn1_buf oid = { .p = NULL, .len = 0, .tag = MBEDTLS_ASN1_NULL }; | 
|  | const x509_attr_descriptor_t *attr_descr = NULL; | 
|  | int in_attr_type = 1; | 
|  | int tag; | 
|  | int numericoid = 0; | 
|  | unsigned char data[MBEDTLS_X509_MAX_DN_NAME_SIZE]; | 
|  | size_t data_len = 0; | 
|  |  | 
|  | /* Clear existing chain if present */ | 
|  | mbedtls_asn1_free_named_data_list(head); | 
|  |  | 
|  | while (c <= end) { | 
|  | if (in_attr_type && *c == '=') { | 
|  | if ((attr_descr = x509_attr_descr_from_name(s, c - s)) == NULL) { | 
|  | if ((mbedtls_oid_from_numeric_string(&oid, s, c - s)) != 0) { | 
|  | return MBEDTLS_ERR_X509_INVALID_NAME; | 
|  | } else { | 
|  | numericoid = 1; | 
|  | } | 
|  | } else { | 
|  | oid.len = strlen(attr_descr->oid); | 
|  | oid.p = mbedtls_calloc(1, oid.len); | 
|  | memcpy(oid.p, attr_descr->oid, oid.len); | 
|  | numericoid = 0; | 
|  | } | 
|  |  | 
|  | s = c + 1; | 
|  | in_attr_type = 0; | 
|  | } | 
|  |  | 
|  | if (!in_attr_type && ((*c == ',' && *(c-1) != '\\') || c == end)) { | 
|  | if (s == c) { | 
|  | mbedtls_free(oid.p); | 
|  | return MBEDTLS_ERR_X509_INVALID_NAME; | 
|  | } else if (*s == '#') { | 
|  | if ((parse_ret = | 
|  | parse_attribute_value_der_encoded(s, (int) (c - s), data, &data_len, | 
|  | &tag)) != 0) { | 
|  | mbedtls_free(oid.p); | 
|  | return MBEDTLS_ERR_X509_INVALID_NAME; | 
|  | } | 
|  | } else { | 
|  | if (numericoid) { | 
|  | mbedtls_free(oid.p); | 
|  | return MBEDTLS_ERR_X509_INVALID_NAME; | 
|  | } else { | 
|  | if ((parse_ret = | 
|  | parse_attribute_value_string(s, (int) (c - s), data, | 
|  | &data_len)) != 0) { | 
|  | mbedtls_free(oid.p); | 
|  | return parse_ret; | 
|  | } | 
|  | tag = attr_descr->default_tag; | 
|  | } | 
|  | } | 
|  |  | 
|  | mbedtls_asn1_named_data *cur = | 
|  | mbedtls_asn1_store_named_data(head, (char *) oid.p, oid.len, | 
|  | (unsigned char *) data, | 
|  | data_len); | 
|  | mbedtls_free(oid.p); | 
|  | oid.p = NULL; | 
|  | if (cur == NULL) { | 
|  | return MBEDTLS_ERR_X509_ALLOC_FAILED; | 
|  | } | 
|  |  | 
|  | // set tagType | 
|  | cur->val.tag = tag; | 
|  |  | 
|  | while (c < end && *(c + 1) == ' ') { | 
|  | c++; | 
|  | } | 
|  |  | 
|  | s = c + 1; | 
|  | in_attr_type = 1; | 
|  |  | 
|  | /* Successfully parsed one name, update ret to success */ | 
|  | ret = 0; | 
|  | } | 
|  | c++; | 
|  | } | 
|  | if (oid.p != NULL) { | 
|  | mbedtls_free(oid.p); | 
|  | } | 
|  | 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 */ |