/*
* X.509 base functions for creating certificates / CSRs
*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
*/
#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>
/* 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 (val_len > (SIZE_MAX - 1)) {
return MBEDTLS_ERR_X509_BAD_INPUT_DATA;
}
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 */