x509write_csr.c 7.66 KB
Newer Older
1 2 3
/*
 *  X.509 Certificate Signing Request writing
 *
Manuel Pégourié-Gonnard's avatar
Manuel Pégourié-Gonnard committed
4
 *  Copyright (C) 2006-2014, ARM Limited, All Rights Reserved
5
 *
6
 *  This file is part of mbed TLS (http://www.polarssl.org)
7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
/*
 * References:
 * - CSRs: PKCS#10 v1.7 aka RFC 2986
 * - attributes: PKCS#9 v2.0 aka RFC 2985
 */

28
#if !defined(POLARSSL_CONFIG_FILE)
29
#include "polarssl/config.h"
30 31 32
#else
#include POLARSSL_CONFIG_FILE
#endif
33 34 35 36 37 38 39 40 41 42 43 44 45 46

#if defined(POLARSSL_X509_CSR_WRITE_C)

#include "polarssl/x509_csr.h"
#include "polarssl/oid.h"
#include "polarssl/asn1write.h"

#if defined(POLARSSL_PEM_WRITE_C)
#include "polarssl/pem.h"
#endif

#include <string.h>
#include <stdlib.h>

47 48 49 50 51
/* Implementation that should never be optimized out by the compiler */
static void polarssl_zeroize( void *v, size_t n ) {
    volatile unsigned char *p = v; while( n-- ) *p++ = 0;
}

52 53 54 55 56 57 58 59 60 61
void x509write_csr_init( x509write_csr *ctx )
{
    memset( ctx, 0, sizeof(x509write_csr) );
}

void x509write_csr_free( x509write_csr *ctx )
{
    asn1_free_named_data_list( &ctx->subject );
    asn1_free_named_data_list( &ctx->extensions );

62
    polarssl_zeroize( ctx, sizeof(x509write_csr) );
63 64 65 66 67 68 69 70 71 72 73 74
}

void x509write_csr_set_md_alg( x509write_csr *ctx, md_type_t md_alg )
{
    ctx->md_alg = md_alg;
}

void x509write_csr_set_key( x509write_csr *ctx, pk_context *key )
{
    ctx->key = key;
}

Paul Bakker's avatar
Paul Bakker committed
75 76
int x509write_csr_set_subject_name( x509write_csr *ctx,
                                    const char *subject_name )
77
{
78
    return x509_string_to_names( &ctx->subject, subject_name );
79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154
}

int x509write_csr_set_extension( x509write_csr *ctx,
                                 const char *oid, size_t oid_len,
                                 const unsigned char *val, size_t val_len )
{
    return x509_set_extension( &ctx->extensions, oid, oid_len,
                               0, val, val_len );
}

int x509write_csr_set_key_usage( x509write_csr *ctx, unsigned char key_usage )
{
    unsigned char buf[4];
    unsigned char *c;
    int ret;

    c = buf + 4;

    if( ( ret = asn1_write_bitstring( &c, buf, &key_usage, 7 ) ) != 4 )
        return( ret );

    ret = x509write_csr_set_extension( ctx, OID_KEY_USAGE,
                                       OID_SIZE( OID_KEY_USAGE ),
                                       buf, 4 );
    if( ret != 0 )
        return( ret );

    return( 0 );
}

int x509write_csr_set_ns_cert_type( x509write_csr *ctx,
                                    unsigned char ns_cert_type )
{
    unsigned char buf[4];
    unsigned char *c;
    int ret;

    c = buf + 4;

    if( ( ret = asn1_write_bitstring( &c, buf, &ns_cert_type, 8 ) ) != 4 )
        return( ret );

    ret = x509write_csr_set_extension( ctx, OID_NS_CERT_TYPE,
                                       OID_SIZE( OID_NS_CERT_TYPE ),
                                       buf, 4 );
    if( ret != 0 )
        return( ret );

    return( 0 );
}

int x509write_csr_der( x509write_csr *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[POLARSSL_MPI_MAX_SIZE];
    unsigned char tmp_buf[2048];
    size_t pub_len = 0, sig_and_oid_len = 0, sig_len;
    size_t len = 0;
    pk_type_t pk_alg;

    /*
     * Prepare data to be signed in tmp_buf
     */
    c = tmp_buf + sizeof( tmp_buf );

    ASN1_CHK_ADD( len, x509_write_extensions( &c, tmp_buf, ctx->extensions ) );

    if( len )
    {
        ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
155 156
        ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED |
                                                        ASN1_SEQUENCE ) );
157 158

        ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
159 160
        ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED |
                                                        ASN1_SET ) );
161 162 163 164 165

        ASN1_CHK_ADD( len, asn1_write_oid( &c, tmp_buf, OID_PKCS9_CSR_EXT_REQ,
                                          OID_SIZE( OID_PKCS9_CSR_EXT_REQ ) ) );

        ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
166 167
        ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED |
                                                        ASN1_SEQUENCE ) );
168 169 170
    }

    ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
171 172
    ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED |
                                                    ASN1_CONTEXT_SPECIFIC ) );
173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189

    ASN1_CHK_ADD( pub_len, pk_write_pubkey_der( ctx->key,
                                                tmp_buf, c - tmp_buf ) );
    c -= pub_len;
    len += pub_len;

    /*
     *  Subject  ::=  Name
     */
    ASN1_CHK_ADD( len, x509_write_names( &c, tmp_buf, ctx->subject ) );

    /*
     *  Version  ::=  INTEGER  {  v1(0), v2(1), v3(2)  }
     */
    ASN1_CHK_ADD( len, asn1_write_int( &c, tmp_buf, 0 ) );

    ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
190 191
    ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED |
                                                    ASN1_SEQUENCE ) );
192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221

    /*
     * Prepare signature
     */
    md( md_info_from_type( ctx->md_alg ), c, len, hash );

    pk_alg = pk_get_type( ctx->key );
    if( pk_alg == POLARSSL_PK_ECKEY )
        pk_alg = POLARSSL_PK_ECDSA;

    if( ( ret = pk_sign( ctx->key, ctx->md_alg, hash, 0, sig, &sig_len,
                         f_rng, p_rng ) ) != 0 ||
        ( ret = oid_get_oid_by_sig_alg( pk_alg, ctx->md_alg,
                                        &sig_oid, &sig_oid_len ) ) != 0 )
    {
        return( ret );
    }

    /*
     * Write data to output buffer
     */
    c2 = buf + size;
    ASN1_CHK_ADD( sig_and_oid_len, x509_write_sig( &c2, buf,
                                        sig_oid, sig_oid_len, sig, sig_len ) );

    c2 -= len;
    memcpy( c2, c, len );

    len += sig_and_oid_len;
    ASN1_CHK_ADD( len, asn1_write_len( &c2, buf, len ) );
222 223
    ASN1_CHK_ADD( len, asn1_write_tag( &c2, buf, ASN1_CONSTRUCTED |
                                                 ASN1_SEQUENCE ) );
224

225
    return( (int) len );
226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257
}

#define PEM_BEGIN_CSR           "-----BEGIN CERTIFICATE REQUEST-----\n"
#define PEM_END_CSR             "-----END CERTIFICATE REQUEST-----\n"

#if defined(POLARSSL_PEM_WRITE_C)
int x509write_csr_pem( x509write_csr *ctx, 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 = x509write_csr_der( ctx, output_buf, sizeof(output_buf),
                                   f_rng, p_rng ) ) < 0 )
    {
        return( ret );
    }

    if( ( ret = pem_write_buffer( PEM_BEGIN_CSR, PEM_END_CSR,
                                  output_buf + sizeof(output_buf) - ret,
                                  ret, buf, size, &olen ) ) != 0 )
    {
        return( ret );
    }

    return( 0 );
}
#endif /* POLARSSL_PEM_WRITE_C */

#endif /* POLARSSL_X509_CSR_WRITE_C */