2 * X.509 Certificate Signing Request writing
4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
5 * SPDX-License-Identifier: Apache-2.0
7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
8 * not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
11 * http://www.apache.org/licenses/LICENSE-2.0
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
19 * This file is part of mbed TLS (https://tls.mbed.org)
23 * - CSRs: PKCS#10 v1.7 aka RFC 2986
24 * - attributes: PKCS#9 v2.0 aka RFC 2985
27 #if !defined(MBEDTLS_CONFIG_FILE)
28 #include "mbedtls/config.h"
30 #include MBEDTLS_CONFIG_FILE
33 #if defined(MBEDTLS_X509_CSR_WRITE_C)
35 #include "mbedtls/x509_csr.h"
36 #include "mbedtls/oid.h"
37 #include "mbedtls/asn1write.h"
42 #if defined(MBEDTLS_PEM_WRITE_C)
43 #include "mbedtls/pem.h"
46 /* Implementation that should never be optimized out by the compiler */
47 static void mbedtls_zeroize( void *v, size_t n ) {
48 volatile unsigned char *p = v; while( n-- ) *p++ = 0;
51 void mbedtls_x509write_csr_init( mbedtls_x509write_csr *ctx )
53 memset( ctx, 0, sizeof(mbedtls_x509write_csr) );
56 void mbedtls_x509write_csr_free( mbedtls_x509write_csr *ctx )
58 mbedtls_asn1_free_named_data_list( &ctx->subject );
59 mbedtls_asn1_free_named_data_list( &ctx->extensions );
61 mbedtls_zeroize( ctx, sizeof(mbedtls_x509write_csr) );
64 void mbedtls_x509write_csr_set_md_alg( mbedtls_x509write_csr *ctx, mbedtls_md_type_t md_alg )
69 void mbedtls_x509write_csr_set_key( mbedtls_x509write_csr *ctx, mbedtls_pk_context *key )
74 int mbedtls_x509write_csr_set_subject_name( mbedtls_x509write_csr *ctx,
75 const char *subject_name )
77 return mbedtls_x509_string_to_names( &ctx->subject, subject_name );
80 int mbedtls_x509write_csr_set_extension( mbedtls_x509write_csr *ctx,
81 const char *oid, size_t oid_len,
82 const unsigned char *val, size_t val_len )
84 return mbedtls_x509_set_extension( &ctx->extensions, oid, oid_len,
88 int mbedtls_x509write_csr_set_key_usage( mbedtls_x509write_csr *ctx, unsigned char key_usage )
96 if( ( ret = mbedtls_asn1_write_bitstring( &c, buf, &key_usage, 7 ) ) != 4 )
99 ret = mbedtls_x509write_csr_set_extension( ctx, MBEDTLS_OID_KEY_USAGE,
100 MBEDTLS_OID_SIZE( MBEDTLS_OID_KEY_USAGE ),
108 int mbedtls_x509write_csr_set_ns_cert_type( mbedtls_x509write_csr *ctx,
109 unsigned char ns_cert_type )
111 unsigned char buf[4];
117 if( ( ret = mbedtls_asn1_write_bitstring( &c, buf, &ns_cert_type, 8 ) ) != 4 )
120 ret = mbedtls_x509write_csr_set_extension( ctx, MBEDTLS_OID_NS_CERT_TYPE,
121 MBEDTLS_OID_SIZE( MBEDTLS_OID_NS_CERT_TYPE ),
129 int mbedtls_x509write_csr_der( mbedtls_x509write_csr *ctx, unsigned char *buf, size_t size,
130 int (*f_rng)(void *, unsigned char *, size_t),
135 size_t sig_oid_len = 0;
136 unsigned char *c, *c2;
137 unsigned char hash[64];
138 unsigned char sig[MBEDTLS_MPI_MAX_SIZE];
139 unsigned char tmp_buf[2048];
140 size_t pub_len = 0, sig_and_oid_len = 0, sig_len;
142 mbedtls_pk_type_t pk_alg;
145 * Prepare data to be signed in tmp_buf
147 c = tmp_buf + sizeof( tmp_buf );
149 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_x509_write_extensions( &c, tmp_buf, ctx->extensions ) );
153 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, len ) );
154 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONSTRUCTED |
155 MBEDTLS_ASN1_SEQUENCE ) );
157 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, len ) );
158 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONSTRUCTED |
159 MBEDTLS_ASN1_SET ) );
161 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_oid( &c, tmp_buf, MBEDTLS_OID_PKCS9_CSR_EXT_REQ,
162 MBEDTLS_OID_SIZE( MBEDTLS_OID_PKCS9_CSR_EXT_REQ ) ) );
164 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, len ) );
165 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONSTRUCTED |
166 MBEDTLS_ASN1_SEQUENCE ) );
169 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, len ) );
170 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONSTRUCTED |
171 MBEDTLS_ASN1_CONTEXT_SPECIFIC ) );
173 MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_pk_write_pubkey_der( ctx->key,
174 tmp_buf, c - tmp_buf ) );
181 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_x509_write_names( &c, tmp_buf, ctx->subject ) );
184 * Version ::= INTEGER { v1(0), v2(1), v3(2) }
186 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_int( &c, tmp_buf, 0 ) );
188 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, len ) );
189 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONSTRUCTED |
190 MBEDTLS_ASN1_SEQUENCE ) );
195 mbedtls_md( mbedtls_md_info_from_type( ctx->md_alg ), c, len, hash );
197 pk_alg = mbedtls_pk_get_type( ctx->key );
198 if( pk_alg == MBEDTLS_PK_ECKEY )
199 pk_alg = MBEDTLS_PK_ECDSA;
201 if( ( ret = mbedtls_pk_sign( ctx->key, ctx->md_alg, hash, 0, sig, &sig_len,
202 f_rng, p_rng ) ) != 0 ||
203 ( ret = mbedtls_oid_get_oid_by_sig_alg( pk_alg, ctx->md_alg,
204 &sig_oid, &sig_oid_len ) ) != 0 )
210 * Write data to output buffer
213 MBEDTLS_ASN1_CHK_ADD( sig_and_oid_len, mbedtls_x509_write_sig( &c2, buf,
214 sig_oid, sig_oid_len, sig, sig_len ) );
216 if( len > (size_t)( c2 - buf ) )
217 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
220 memcpy( c2, c, len );
222 len += sig_and_oid_len;
223 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c2, buf, len ) );
224 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c2, buf, MBEDTLS_ASN1_CONSTRUCTED |
225 MBEDTLS_ASN1_SEQUENCE ) );
230 #define PEM_BEGIN_CSR "-----BEGIN CERTIFICATE REQUEST-----\n"
231 #define PEM_END_CSR "-----END CERTIFICATE REQUEST-----\n"
233 #if defined(MBEDTLS_PEM_WRITE_C)
234 int mbedtls_x509write_csr_pem( mbedtls_x509write_csr *ctx, unsigned char *buf, size_t size,
235 int (*f_rng)(void *, unsigned char *, size_t),
239 unsigned char output_buf[4096];
242 if( ( ret = mbedtls_x509write_csr_der( ctx, output_buf, sizeof(output_buf),
243 f_rng, p_rng ) ) < 0 )
248 if( ( ret = mbedtls_pem_write_buffer( PEM_BEGIN_CSR, PEM_END_CSR,
249 output_buf + sizeof(output_buf) - ret,
250 ret, buf, size, &olen ) ) != 0 )
257 #endif /* MBEDTLS_PEM_WRITE_C */
259 #endif /* MBEDTLS_X509_CSR_WRITE_C */