/* | |
* X.509 certificate writing | |
* | |
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved | |
* 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. | |
* | |
* This file is part of mbed TLS (https://tls.mbed.org) | |
*/ | |
/* | |
* References: | |
* - certificates: RFC 5280, updated by RFC 6818 | |
* - CSRs: PKCS#10 v1.7 aka RFC 2986 | |
* - attributes: PKCS#9 v2.0 aka RFC 2985 | |
*/ | |
#if !defined(MBEDTLS_CONFIG_FILE) | |
#include "mbedtls/config.h" | |
#else | |
#include MBEDTLS_CONFIG_FILE | |
#endif | |
#if defined(MBEDTLS_X509_CRT_WRITE_C) | |
#include "mbedtls/x509_crt.h" | |
#include "mbedtls/oid.h" | |
#include "mbedtls/asn1write.h" | |
#include "mbedtls/sha1.h" | |
#include "mbedtls/platform_util.h" | |
#include <string.h> | |
#if defined(MBEDTLS_PEM_WRITE_C) | |
#include "mbedtls/pem.h" | |
#endif /* MBEDTLS_PEM_WRITE_C */ | |
void mbedtls_x509write_crt_init( mbedtls_x509write_cert *ctx ) | |
{ | |
memset( ctx, 0, sizeof( mbedtls_x509write_cert ) ); | |
mbedtls_mpi_init( &ctx->serial ); | |
ctx->version = MBEDTLS_X509_CRT_VERSION_3; | |
} | |
void mbedtls_x509write_crt_free( mbedtls_x509write_cert *ctx ) | |
{ | |
mbedtls_mpi_free( &ctx->serial ); | |
mbedtls_asn1_free_named_data_list( &ctx->subject ); | |
mbedtls_asn1_free_named_data_list( &ctx->issuer ); | |
mbedtls_asn1_free_named_data_list( &ctx->extensions ); | |
mbedtls_platform_zeroize( ctx, sizeof( mbedtls_x509write_cert ) ); | |
} | |
void mbedtls_x509write_crt_set_version( mbedtls_x509write_cert *ctx, int version ) | |
{ | |
ctx->version = version; | |
} | |
void mbedtls_x509write_crt_set_md_alg( mbedtls_x509write_cert *ctx, mbedtls_md_type_t md_alg ) | |
{ | |
ctx->md_alg = md_alg; | |
} | |
void mbedtls_x509write_crt_set_subject_key( mbedtls_x509write_cert *ctx, mbedtls_pk_context *key ) | |
{ | |
ctx->subject_key = key; | |
} | |
void mbedtls_x509write_crt_set_issuer_key( mbedtls_x509write_cert *ctx, mbedtls_pk_context *key ) | |
{ | |
ctx->issuer_key = key; | |
} | |
int mbedtls_x509write_crt_set_subject_name( mbedtls_x509write_cert *ctx, | |
const char *subject_name ) | |
{ | |
return mbedtls_x509_string_to_names( &ctx->subject, subject_name ); | |
} | |
int mbedtls_x509write_crt_set_issuer_name( mbedtls_x509write_cert *ctx, | |
const char *issuer_name ) | |
{ | |
return mbedtls_x509_string_to_names( &ctx->issuer, issuer_name ); | |
} | |
int mbedtls_x509write_crt_set_serial( mbedtls_x509write_cert *ctx, const mbedtls_mpi *serial ) | |
{ | |
int ret; | |
if( ( ret = mbedtls_mpi_copy( &ctx->serial, serial ) ) != 0 ) | |
return( ret ); | |
return( 0 ); | |
} | |
int mbedtls_x509write_crt_set_validity( mbedtls_x509write_cert *ctx, const char *not_before, | |
const char *not_after ) | |
{ | |
if( strlen( not_before ) != MBEDTLS_X509_RFC5280_UTC_TIME_LEN - 1 || | |
strlen( not_after ) != MBEDTLS_X509_RFC5280_UTC_TIME_LEN - 1 ) | |
{ | |
return( MBEDTLS_ERR_X509_BAD_INPUT_DATA ); | |
} | |
strncpy( ctx->not_before, not_before, MBEDTLS_X509_RFC5280_UTC_TIME_LEN ); | |
strncpy( ctx->not_after , not_after , MBEDTLS_X509_RFC5280_UTC_TIME_LEN ); | |
ctx->not_before[MBEDTLS_X509_RFC5280_UTC_TIME_LEN - 1] = 'Z'; | |
ctx->not_after[MBEDTLS_X509_RFC5280_UTC_TIME_LEN - 1] = 'Z'; | |
return( 0 ); | |
} | |
int mbedtls_x509write_crt_set_extension( mbedtls_x509write_cert *ctx, | |
const char *oid, size_t oid_len, | |
int critical, | |
const unsigned char *val, size_t val_len ) | |
{ | |
return mbedtls_x509_set_extension( &ctx->extensions, oid, oid_len, | |
critical, val, val_len ); | |
} | |
int mbedtls_x509write_crt_set_basic_constraints( mbedtls_x509write_cert *ctx, | |
int is_ca, int max_pathlen ) | |
{ | |
int ret; | |
unsigned char buf[9]; | |
unsigned char *c = buf + sizeof(buf); | |
size_t len = 0; | |
memset( buf, 0, sizeof(buf) ); | |
if( is_ca && max_pathlen > 127 ) | |
return( MBEDTLS_ERR_X509_BAD_INPUT_DATA ); | |
if( is_ca ) | |
{ | |
if( max_pathlen >= 0 ) | |
{ | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_int( &c, buf, max_pathlen ) ); | |
} | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_bool( &c, buf, 1 ) ); | |
} | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) ); | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONSTRUCTED | | |
MBEDTLS_ASN1_SEQUENCE ) ); | |
return mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_BASIC_CONSTRAINTS, | |
MBEDTLS_OID_SIZE( MBEDTLS_OID_BASIC_CONSTRAINTS ), | |
0, buf + sizeof(buf) - len, len ); | |
} | |
#if defined(MBEDTLS_SHA1_C) | |
int mbedtls_x509write_crt_set_subject_key_identifier( mbedtls_x509write_cert *ctx ) | |
{ | |
int ret; | |
unsigned char buf[MBEDTLS_MPI_MAX_SIZE * 2 + 20]; /* tag, length + 2xMPI */ | |
unsigned char *c = buf + sizeof(buf); | |
size_t len = 0; | |
memset( buf, 0, sizeof(buf) ); | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_pk_write_pubkey( &c, buf, ctx->subject_key ) ); | |
ret = mbedtls_sha1_ret( buf + sizeof( buf ) - len, len, | |
buf + sizeof( buf ) - 20 ); | |
if( ret != 0 ) | |
return( ret ); | |
c = buf + sizeof( buf ) - 20; | |
len = 20; | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) ); | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_OCTET_STRING ) ); | |
return mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_SUBJECT_KEY_IDENTIFIER, | |
MBEDTLS_OID_SIZE( MBEDTLS_OID_SUBJECT_KEY_IDENTIFIER ), | |
0, buf + sizeof(buf) - len, len ); | |
} | |
int mbedtls_x509write_crt_set_authority_key_identifier( mbedtls_x509write_cert *ctx ) | |
{ | |
int ret; | |
unsigned char buf[MBEDTLS_MPI_MAX_SIZE * 2 + 20]; /* tag, length + 2xMPI */ | |
unsigned char *c = buf + sizeof( buf ); | |
size_t len = 0; | |
memset( buf, 0, sizeof(buf) ); | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_pk_write_pubkey( &c, buf, ctx->issuer_key ) ); | |
ret = mbedtls_sha1_ret( buf + sizeof( buf ) - len, len, | |
buf + sizeof( buf ) - 20 ); | |
if( ret != 0 ) | |
return( ret ); | |
c = buf + sizeof( buf ) - 20; | |
len = 20; | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) ); | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONTEXT_SPECIFIC | 0 ) ); | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) ); | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONSTRUCTED | | |
MBEDTLS_ASN1_SEQUENCE ) ); | |
return mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_AUTHORITY_KEY_IDENTIFIER, | |
MBEDTLS_OID_SIZE( MBEDTLS_OID_AUTHORITY_KEY_IDENTIFIER ), | |
0, buf + sizeof( buf ) - len, len ); | |
} | |
#endif /* MBEDTLS_SHA1_C */ | |
int mbedtls_x509write_crt_set_key_usage( mbedtls_x509write_cert *ctx, | |
unsigned int key_usage ) | |
{ | |
unsigned char buf[5], ku[2]; | |
unsigned char *c; | |
int ret; | |
const unsigned int allowed_bits = MBEDTLS_X509_KU_DIGITAL_SIGNATURE | | |
MBEDTLS_X509_KU_NON_REPUDIATION | | |
MBEDTLS_X509_KU_KEY_ENCIPHERMENT | | |
MBEDTLS_X509_KU_DATA_ENCIPHERMENT | | |
MBEDTLS_X509_KU_KEY_AGREEMENT | | |
MBEDTLS_X509_KU_KEY_CERT_SIGN | | |
MBEDTLS_X509_KU_CRL_SIGN | | |
MBEDTLS_X509_KU_ENCIPHER_ONLY | | |
MBEDTLS_X509_KU_DECIPHER_ONLY; | |
/* Check that nothing other than the allowed flags is set */ | |
if( ( key_usage & ~allowed_bits ) != 0 ) | |
return( MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE ); | |
c = buf + 5; | |
ku[0] = (unsigned char)( key_usage ); | |
ku[1] = (unsigned char)( key_usage >> 8 ); | |
ret = mbedtls_asn1_write_named_bitstring( &c, buf, ku, 9 ); | |
if( ret < 0 ) | |
return( ret ); | |
else if( ret < 3 || ret > 5 ) | |
return( MBEDTLS_ERR_X509_INVALID_FORMAT ); | |
ret = mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_KEY_USAGE, | |
MBEDTLS_OID_SIZE( MBEDTLS_OID_KEY_USAGE ), | |
1, c, (size_t)ret ); | |
if( ret != 0 ) | |
return( ret ); | |
return( 0 ); | |
} | |
int mbedtls_x509write_crt_set_ns_cert_type( mbedtls_x509write_cert *ctx, | |
unsigned char ns_cert_type ) | |
{ | |
unsigned char buf[4]; | |
unsigned char *c; | |
int ret; | |
c = buf + 4; | |
ret = mbedtls_asn1_write_named_bitstring( &c, buf, &ns_cert_type, 8 ); | |
if( ret < 3 || ret > 4 ) | |
return( ret ); | |
ret = mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_NS_CERT_TYPE, | |
MBEDTLS_OID_SIZE( MBEDTLS_OID_NS_CERT_TYPE ), | |
0, c, (size_t)ret ); | |
if( ret != 0 ) | |
return( ret ); | |
return( 0 ); | |
} | |
static int x509_write_time( unsigned char **p, unsigned char *start, | |
const char *t, size_t size ) | |
{ | |
int ret; | |
size_t len = 0; | |
/* | |
* write MBEDTLS_ASN1_UTC_TIME if year < 2050 (2 bytes shorter) | |
*/ | |
if( t[0] == '2' && t[1] == '0' && t[2] < '5' ) | |
{ | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start, | |
(const unsigned char *) t + 2, | |
size - 2 ) ); | |
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_UTC_TIME ) ); | |
} | |
else | |
{ | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start, | |
(const unsigned char *) t, | |
size ) ); | |
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_GENERALIZED_TIME ) ); | |
} | |
return( (int) len ); | |
} | |
int mbedtls_x509write_crt_der( mbedtls_x509write_cert *ctx, unsigned char *buf, size_t size, | |
int (*f_rng)(void *, unsigned char *, size_t), | |
void *p_rng ) | |
{ | |
int ret; | |
const char *sig_oid; | |
size_t sig_oid_len = 0; | |
unsigned char *c, *c2; | |
unsigned char hash[64]; | |
unsigned char sig[MBEDTLS_MPI_MAX_SIZE]; | |
unsigned char tmp_buf[2048]; | |
size_t sub_len = 0, pub_len = 0, sig_and_oid_len = 0, sig_len; | |
size_t len = 0; | |
mbedtls_pk_type_t pk_alg; | |
/* | |
* Prepare data to be signed in tmp_buf | |
*/ | |
c = tmp_buf + sizeof( tmp_buf ); | |
/* Signature algorithm needed in TBS, and later for actual signature */ | |
/* There's no direct way of extracting a signature algorithm | |
* (represented as an element of mbedtls_pk_type_t) from a PK instance. */ | |
if( mbedtls_pk_can_do( ctx->issuer_key, MBEDTLS_PK_RSA ) ) | |
pk_alg = MBEDTLS_PK_RSA; | |
else if( mbedtls_pk_can_do( ctx->issuer_key, MBEDTLS_PK_ECDSA ) ) | |
pk_alg = MBEDTLS_PK_ECDSA; | |
else | |
return( MBEDTLS_ERR_X509_INVALID_ALG ); | |
if( ( ret = mbedtls_oid_get_oid_by_sig_alg( pk_alg, ctx->md_alg, | |
&sig_oid, &sig_oid_len ) ) != 0 ) | |
{ | |
return( ret ); | |
} | |
/* | |
* Extensions ::= SEQUENCE SIZE (1..MAX) OF Extension | |
*/ | |
/* Only for v3 */ | |
if( ctx->version == MBEDTLS_X509_CRT_VERSION_3 ) | |
{ | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_x509_write_extensions( &c, tmp_buf, ctx->extensions ) ); | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, len ) ); | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONSTRUCTED | | |
MBEDTLS_ASN1_SEQUENCE ) ); | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, len ) ); | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONTEXT_SPECIFIC | | |
MBEDTLS_ASN1_CONSTRUCTED | 3 ) ); | |
} | |
/* | |
* SubjectPublicKeyInfo | |
*/ | |
MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_pk_write_pubkey_der( ctx->subject_key, | |
tmp_buf, c - tmp_buf ) ); | |
c -= pub_len; | |
len += pub_len; | |
/* | |
* Subject ::= Name | |
*/ | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_x509_write_names( &c, tmp_buf, ctx->subject ) ); | |
/* | |
* Validity ::= SEQUENCE { | |
* notBefore Time, | |
* notAfter Time } | |
*/ | |
sub_len = 0; | |
MBEDTLS_ASN1_CHK_ADD( sub_len, x509_write_time( &c, tmp_buf, ctx->not_after, | |
MBEDTLS_X509_RFC5280_UTC_TIME_LEN ) ); | |
MBEDTLS_ASN1_CHK_ADD( sub_len, x509_write_time( &c, tmp_buf, ctx->not_before, | |
MBEDTLS_X509_RFC5280_UTC_TIME_LEN ) ); | |
len += sub_len; | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, sub_len ) ); | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONSTRUCTED | | |
MBEDTLS_ASN1_SEQUENCE ) ); | |
/* | |
* Issuer ::= Name | |
*/ | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_x509_write_names( &c, tmp_buf, ctx->issuer ) ); | |
/* | |
* Signature ::= AlgorithmIdentifier | |
*/ | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_algorithm_identifier( &c, tmp_buf, | |
sig_oid, strlen( sig_oid ), 0 ) ); | |
/* | |
* Serial ::= INTEGER | |
*/ | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, tmp_buf, &ctx->serial ) ); | |
/* | |
* Version ::= INTEGER { v1(0), v2(1), v3(2) } | |
*/ | |
/* Can be omitted for v1 */ | |
if( ctx->version != MBEDTLS_X509_CRT_VERSION_1 ) | |
{ | |
sub_len = 0; | |
MBEDTLS_ASN1_CHK_ADD( sub_len, mbedtls_asn1_write_int( &c, tmp_buf, ctx->version ) ); | |
len += sub_len; | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, sub_len ) ); | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONTEXT_SPECIFIC | | |
MBEDTLS_ASN1_CONSTRUCTED | 0 ) ); | |
} | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, len ) ); | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONSTRUCTED | | |
MBEDTLS_ASN1_SEQUENCE ) ); | |
/* | |
* Make signature | |
*/ | |
if( ( ret = mbedtls_md( mbedtls_md_info_from_type( ctx->md_alg ), c, | |
len, hash ) ) != 0 ) | |
{ | |
return( ret ); | |
} | |
if( ( ret = mbedtls_pk_sign( ctx->issuer_key, ctx->md_alg, hash, 0, sig, &sig_len, | |
f_rng, p_rng ) ) != 0 ) | |
{ | |
return( ret ); | |
} | |
/* | |
* Write data to output buffer | |
*/ | |
c2 = buf + size; | |
MBEDTLS_ASN1_CHK_ADD( sig_and_oid_len, mbedtls_x509_write_sig( &c2, buf, | |
sig_oid, sig_oid_len, sig, sig_len ) ); | |
if( len > (size_t)( c2 - buf ) ) | |
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); | |
c2 -= len; | |
memcpy( c2, c, len ); | |
len += sig_and_oid_len; | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c2, buf, len ) ); | |
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c2, buf, MBEDTLS_ASN1_CONSTRUCTED | | |
MBEDTLS_ASN1_SEQUENCE ) ); | |
return( (int) len ); | |
} | |
#define PEM_BEGIN_CRT "-----BEGIN CERTIFICATE-----\n" | |
#define PEM_END_CRT "-----END CERTIFICATE-----\n" | |
#if defined(MBEDTLS_PEM_WRITE_C) | |
int mbedtls_x509write_crt_pem( mbedtls_x509write_cert *crt, unsigned char *buf, size_t size, | |
int (*f_rng)(void *, unsigned char *, size_t), | |
void *p_rng ) | |
{ | |
int ret; | |
unsigned char output_buf[4096]; | |
size_t olen = 0; | |
if( ( ret = mbedtls_x509write_crt_der( crt, output_buf, sizeof(output_buf), | |
f_rng, p_rng ) ) < 0 ) | |
{ | |
return( ret ); | |
} | |
if( ( ret = mbedtls_pem_write_buffer( PEM_BEGIN_CRT, PEM_END_CRT, | |
output_buf + sizeof(output_buf) - ret, | |
ret, buf, size, &olen ) ) != 0 ) | |
{ | |
return( ret ); | |
} | |
return( 0 ); | |
} | |
#endif /* MBEDTLS_PEM_WRITE_C */ | |
#endif /* MBEDTLS_X509_CRT_WRITE_C */ |