int x509_write_sig( unsigned char **p, unsigned char *start,
const char *oid, size_t oid_len,
unsigned char *sig, size_t size )
{
int ret;
size_t len = 0;
if( *p - start < (int) size + 1 )
return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );
len = size;
(*p) -= len;
memcpy( *p, sig, len );
*--(*p) = 0;
len += 1;
ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_BIT_STRING ) );
// Write OID
//
ASN1_CHK_ADD( len, asn1_write_algorithm_identifier( p, start, oid,
oid_len, 0 ) );
return( (int) len );
}
int x509_write_pubkey_der( unsigned char *buf, size_t size, rsa_context *rsa )
{
int ret;
unsigned char *c;
size_t len = 0;
c = buf + size - 1;
ASN1_CHK_ADD( len, asn1_write_mpi( &c, buf, &rsa->E ) );
ASN1_CHK_ADD( len, asn1_write_mpi( &c, buf, &rsa->N ) );
ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
ASN1_CHK_ADD( len, asn1_write_tag( &c, buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
if( c - buf < 1 )
return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );
*--c = 0;
len += 1;
ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
ASN1_CHK_ADD( len, asn1_write_tag( &c, buf, ASN1_BIT_STRING ) );
ASN1_CHK_ADD( len, asn1_write_algorithm_identifier( &c, buf, OID_PKCS1_RSA ) );
ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
ASN1_CHK_ADD( len, asn1_write_tag( &c, buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
return( len );
}
int pk_write_pubkey_der( pk_context *key, unsigned char *buf, size_t size )
{
int ret;
unsigned char *c;
size_t len = 0, par_len = 0, oid_len;
const char *oid;
c = buf + size;
ASN1_CHK_ADD( len, pk_write_pubkey( &c, buf, key ) );
if( c - buf < 1 ) {
return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );
}
/*
* SubjectPublicKeyInfo ::= SEQUENCE {
* algorithm AlgorithmIdentifier,
* subjectPublicKey BIT STRING }
*/
*--c = 0;
len += 1;
ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
ASN1_CHK_ADD( len, asn1_write_tag( &c, buf, ASN1_BIT_STRING ) );
/* If we return here (do not write OID)
* the result will look OK... */
/* return len; */
if( ( ret = oid_get_oid_by_pk_alg( pk_get_type( key ),
&oid, &oid_len ) ) != 0 )
{
return( ret );
}
#if defined(POLARSSL_ECP_C)
if( pk_get_type( key ) == POLARSSL_PK_ECKEY )
{
ASN1_CHK_ADD( par_len, pk_write_ec_param( &c, buf, pk_ec( *key ) ) );
}
#endif
ASN1_CHK_ADD( len, asn1_write_algorithm_identifier( &c, buf, oid, oid_len,
par_len ) );
ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
ASN1_CHK_ADD( len, asn1_write_tag( &c, buf, ASN1_CONSTRUCTED |
ASN1_SEQUENCE ) );
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 );
}
int x509_write_cert_req( unsigned char *buf, size_t size, rsa_context *rsa,
x509_req_name *req_name, int hash_id )
{
int ret;
char sig_oid[10];
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_len = 0;
size_t len = 0;
x509_req_name *cur = req_name;
c = tmp_buf + 2048 - 1;
ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, 0 ) );
ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED | ASN1_CONTEXT_SPECIFIC ) );
ASN1_CHK_ADD( pub_len, asn1_write_mpi( &c, tmp_buf, &rsa->E ) );
ASN1_CHK_ADD( pub_len, asn1_write_mpi( &c, tmp_buf, &rsa->N ) );
ASN1_CHK_ADD( pub_len, asn1_write_len( &c, tmp_buf, pub_len ) );
ASN1_CHK_ADD( pub_len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
if( c - tmp_buf < 1 )
return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );
*--c = 0;
pub_len += 1;
ASN1_CHK_ADD( pub_len, asn1_write_len( &c, tmp_buf, pub_len ) );
ASN1_CHK_ADD( pub_len, asn1_write_tag( &c, tmp_buf, ASN1_BIT_STRING ) );
ASN1_CHK_ADD( pub_len, asn1_write_algorithm_identifier( &c, tmp_buf, OID_PKCS1_RSA ) );
len += pub_len;
ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, pub_len ) );
ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
while( cur != NULL )
{
ASN1_CHK_ADD( sub_len, x509_write_name( &c, tmp_buf, cur->oid, cur->name ) );
cur = cur->next;
}
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 ) );
ASN1_CHK_ADD( len, asn1_write_int( &c, tmp_buf, 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 ) );
x509_hash( c, len, hash_id, hash );
rsa_pkcs1_sign( rsa, NULL, NULL, RSA_PRIVATE, hash_id, 0, hash, sig );
// Generate correct OID
//
memcpy( sig_oid, OID_PKCS1, 8 );
sig_oid[8] = hash_id;
sig_oid[9] = '\0';
c2 = buf + size - 1;
ASN1_CHK_ADD( sig_len, x509_write_sig( &c2, buf, sig_oid, sig, rsa->len ) );
c2 -= len;
memcpy( c2, c, len );
len += sig_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( len );
}
