blob: e298c24ecf02f7c4712f707e023fa2c73a525532 [file] [log] [blame]
/*
* X.509 certificate writing
*
* Copyright (C) 2006-2014, Brainspark B.V.
*
* This file is part of PolarSSL (http://www.polarssl.org)
* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
*
* All rights reserved.
*
* 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:
* - 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(POLARSSL_CONFIG_FILE)
#include "polarssl/config.h"
#else
#include POLARSSL_CONFIG_FILE
#endif
#if defined(POLARSSL_X509_CRT_WRITE_C)
#include "polarssl/x509_crt.h"
#include "polarssl/oid.h"
#include "polarssl/asn1write.h"
#include "polarssl/sha1.h"
#if defined(POLARSSL_PEM_WRITE_C)
#include "polarssl/pem.h"
#endif /* POLARSSL_PEM_WRITE_C */
/* 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;
}
void x509write_crt_init( x509write_cert *ctx )
{
memset( ctx, 0, sizeof(x509write_cert) );
mpi_init( &ctx->serial );
ctx->version = X509_CRT_VERSION_3;
}
void x509write_crt_free( x509write_cert *ctx )
{
mpi_free( &ctx->serial );
asn1_free_named_data_list( &ctx->subject );
asn1_free_named_data_list( &ctx->issuer );
asn1_free_named_data_list( &ctx->extensions );
polarssl_zeroize( ctx, sizeof(x509write_cert) );
}
void x509write_crt_set_version( x509write_cert *ctx, int version )
{
ctx->version = version;
}
void x509write_crt_set_md_alg( x509write_cert *ctx, md_type_t md_alg )
{
ctx->md_alg = md_alg;
}
void x509write_crt_set_subject_key( x509write_cert *ctx, pk_context *key )
{
ctx->subject_key = key;
}
void x509write_crt_set_issuer_key( x509write_cert *ctx, pk_context *key )
{
ctx->issuer_key = key;
}
int x509write_crt_set_subject_name( x509write_cert *ctx,
const char *subject_name )
{
return x509_string_to_names( &ctx->subject, subject_name );
}
int x509write_crt_set_issuer_name( x509write_cert *ctx,
const char *issuer_name )
{
return x509_string_to_names( &ctx->issuer, issuer_name );
}
int x509write_crt_set_serial( x509write_cert *ctx, const mpi *serial )
{
int ret;
if( ( ret = mpi_copy( &ctx->serial, serial ) ) != 0 )
return( ret );
return( 0 );
}
int x509write_crt_set_validity( x509write_cert *ctx, const char *not_before,
const char *not_after )
{
if( strlen( not_before ) != X509_RFC5280_UTC_TIME_LEN - 1 ||
strlen( not_after ) != X509_RFC5280_UTC_TIME_LEN - 1 )
{
return( POLARSSL_ERR_X509_BAD_INPUT_DATA );
}
strncpy( ctx->not_before, not_before, X509_RFC5280_UTC_TIME_LEN );
strncpy( ctx->not_after , not_after , X509_RFC5280_UTC_TIME_LEN );
ctx->not_before[X509_RFC5280_UTC_TIME_LEN - 1] = 'Z';
ctx->not_after[X509_RFC5280_UTC_TIME_LEN - 1] = 'Z';
return( 0 );
}
int x509write_crt_set_extension( x509write_cert *ctx,
const char *oid, size_t oid_len,
int critical,
const unsigned char *val, size_t val_len )
{
return x509_set_extension( &ctx->extensions, oid, oid_len,
critical, val, val_len );
}
int x509write_crt_set_basic_constraints( 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( POLARSSL_ERR_X509_BAD_INPUT_DATA );
if( is_ca )
{
if( max_pathlen >= 0 )
{
ASN1_CHK_ADD( len, asn1_write_int( &c, buf, max_pathlen ) );
}
ASN1_CHK_ADD( len, asn1_write_bool( &c, buf, 1 ) );
}
ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
ASN1_CHK_ADD( len, asn1_write_tag( &c, buf, ASN1_CONSTRUCTED |
ASN1_SEQUENCE ) );
return x509write_crt_set_extension( ctx, OID_BASIC_CONSTRAINTS,
OID_SIZE( OID_BASIC_CONSTRAINTS ),
0, buf + sizeof(buf) - len, len );
}
#if defined(POLARSSL_SHA1_C)
int x509write_crt_set_subject_key_identifier( x509write_cert *ctx )
{
int ret;
unsigned char buf[POLARSSL_MPI_MAX_SIZE * 2 + 20]; /* tag, length + 2xMPI */
unsigned char *c = buf + sizeof(buf);
size_t len = 0;
memset( buf, 0, sizeof(buf) );
ASN1_CHK_ADD( len, pk_write_pubkey( &c, buf, ctx->subject_key ) );
sha1( buf + sizeof(buf) - len, len, buf + sizeof(buf) - 20 );
c = buf + sizeof(buf) - 20;
len = 20;
ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
ASN1_CHK_ADD( len, asn1_write_tag( &c, buf, ASN1_OCTET_STRING ) );
return x509write_crt_set_extension( ctx, OID_SUBJECT_KEY_IDENTIFIER,
OID_SIZE( OID_SUBJECT_KEY_IDENTIFIER ),
0, buf + sizeof(buf) - len, len );
}
int x509write_crt_set_authority_key_identifier( x509write_cert *ctx )
{
int ret;
unsigned char buf[POLARSSL_MPI_MAX_SIZE * 2 + 20]; /* tag, length + 2xMPI */
unsigned char *c = buf + sizeof(buf);
size_t len = 0;
memset( buf, 0, sizeof(buf) );
ASN1_CHK_ADD( len, pk_write_pubkey( &c, buf, ctx->issuer_key ) );
sha1( buf + sizeof(buf) - len, len, buf + sizeof(buf) - 20 );
c = buf + sizeof(buf) - 20;
len = 20;
ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
ASN1_CHK_ADD( len, asn1_write_tag( &c, buf, ASN1_CONTEXT_SPECIFIC | 0 ) );
ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
ASN1_CHK_ADD( len, asn1_write_tag( &c, buf, ASN1_CONSTRUCTED |
ASN1_SEQUENCE ) );
return x509write_crt_set_extension( ctx, OID_AUTHORITY_KEY_IDENTIFIER,
OID_SIZE( OID_AUTHORITY_KEY_IDENTIFIER ),
0, buf + sizeof(buf) - len, len );
}
#endif /* POLARSSL_SHA1_C */
int x509write_crt_set_key_usage( x509write_cert *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_crt_set_extension( ctx, OID_KEY_USAGE,
OID_SIZE( OID_KEY_USAGE ),
1, buf, 4 );
if( ret != 0 )
return( ret );
return( 0 );
}
int x509write_crt_set_ns_cert_type( x509write_cert *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_crt_set_extension( ctx, OID_NS_CERT_TYPE,
OID_SIZE( OID_NS_CERT_TYPE ),
0, buf, 4 );
if( ret != 0 )
return( ret );
return( 0 );
}
static int x509_write_time( unsigned char **p, unsigned char *start,
const char *time, size_t size )
{
int ret;
size_t len = 0;
/*
* write ASN1_UTC_TIME if year < 2050 (2 bytes shorter)
*/
if( time[0] == '2' && time[1] == '0' && time [2] < '5' )
{
ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start,
(const unsigned char *) time + 2,
size - 2 ) );
ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_UTC_TIME ) );
}
else
{
ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start,
(const unsigned char *) time,
size ) );
ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_GENERALIZED_TIME ) );
}
return( (int) len );
}
int x509write_crt_der( 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[POLARSSL_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;
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 */
pk_alg = pk_get_type( ctx->issuer_key );
if( pk_alg == POLARSSL_PK_ECKEY )
pk_alg = POLARSSL_PK_ECDSA;
if( ( ret = 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
*/
ASN1_CHK_ADD( len, x509_write_extensions( &c, tmp_buf, ctx->extensions ) );
ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED |
ASN1_SEQUENCE ) );
ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONTEXT_SPECIFIC |
ASN1_CONSTRUCTED | 3 ) );
/*
* SubjectPublicKeyInfo
*/
ASN1_CHK_ADD( pub_len, pk_write_pubkey_der( ctx->subject_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 ) );
/*
* Validity ::= SEQUENCE {
* notBefore Time,
* notAfter Time }
*/
sub_len = 0;
ASN1_CHK_ADD( sub_len, x509_write_time( &c, tmp_buf, ctx->not_after,
X509_RFC5280_UTC_TIME_LEN ) );
ASN1_CHK_ADD( sub_len, x509_write_time( &c, tmp_buf, ctx->not_before,
X509_RFC5280_UTC_TIME_LEN ) );
len += sub_len;
ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, sub_len ) );
ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED |
ASN1_SEQUENCE ) );
/*
* Issuer ::= Name
*/
ASN1_CHK_ADD( len, x509_write_names( &c, tmp_buf, ctx->issuer ) );
/*
* Signature ::= AlgorithmIdentifier
*/
ASN1_CHK_ADD( len, asn1_write_algorithm_identifier( &c, tmp_buf,
sig_oid, strlen( sig_oid ), 0 ) );
/*
* Serial ::= INTEGER
*/
ASN1_CHK_ADD( len, asn1_write_mpi( &c, tmp_buf, &ctx->serial ) );
/*
* Version ::= INTEGER { v1(0), v2(1), v3(2) }
*/
sub_len = 0;
ASN1_CHK_ADD( sub_len, asn1_write_int( &c, tmp_buf, ctx->version ) );
len += sub_len;
ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, sub_len ) );
ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONTEXT_SPECIFIC |
ASN1_CONSTRUCTED | 0 ) );
ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED |
ASN1_SEQUENCE ) );
/*
* Make signature
*/
md( md_info_from_type( ctx->md_alg ), c, len, hash );
if( ( ret = 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;
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 ) );
ASN1_CHK_ADD( len, asn1_write_tag( &c2, buf, ASN1_CONSTRUCTED |
ASN1_SEQUENCE ) );
return( (int) len );
}
#define PEM_BEGIN_CRT "-----BEGIN CERTIFICATE-----\n"
#define PEM_END_CRT "-----END CERTIFICATE-----\n"
#if defined(POLARSSL_PEM_WRITE_C)
int x509write_crt_pem( 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 = x509write_crt_der( crt, output_buf, sizeof(output_buf),
f_rng, p_rng ) ) < 0 )
{
return( ret );
}
if( ( ret = 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 /* POLARSSL_PEM_WRITE_C */
#endif /* POLARSSL_X509_CRT_WRITE_C */