/*
* SubjectPublicKeyInfo ::= SEQUENCE {
* algorithm AlgorithmIdentifier,
* subjectPublicKey BIT STRING }
*/
int pk_parse_subpubkey( unsigned char **p, const unsigned char *end,
pk_context *pk )
{
int ret;
size_t len;
asn1_buf alg_params;
pk_type_t pk_alg = POLARSSL_PK_NONE;
const pk_info_t *pk_info;
if( ( ret = asn1_get_tag( p, end, &len,
ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
{
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
}
end = *p + len;
if( ( ret = pk_get_pk_alg( p, end, &pk_alg, &alg_params ) ) != 0 )
return( ret );
if( ( ret = asn1_get_bitstring_null( p, end, &len ) ) != 0 )
return( POLARSSL_ERR_PK_INVALID_PUBKEY + ret );
if( *p + len != end )
return( POLARSSL_ERR_PK_INVALID_PUBKEY +
POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
if( ( pk_info = pk_info_from_type( pk_alg ) ) == NULL )
return( POLARSSL_ERR_PK_UNKNOWN_PK_ALG );
if( ( ret = pk_init_ctx( pk, pk_info ) ) != 0 )
return( ret );
#if defined(POLARSSL_RSA_C)
if( pk_alg == POLARSSL_PK_RSA )
{
ret = pk_get_shrsapubkey( p, end, pk_rsa( *pk ) );
} else
#endif /* POLARSSL_RSA_C */
#if defined(POLARSSL_ECP_C)
if( pk_alg == POLARSSL_PK_ECKEY_DH || pk_alg == POLARSSL_PK_ECKEY )
{
ret = pk_use_ecparams( &alg_params, &pk_ec( *pk )->grp );
if( ret == 0 )
ret = pk_get_ecpubkey( p, end, pk_ec( *pk ) );
} else
#endif /* POLARSSL_ECP_C */
ret = POLARSSL_ERR_PK_UNKNOWN_PK_ALG;
if( ret == 0 && *p != end )
ret = POLARSSL_ERR_PK_INVALID_PUBKEY
POLARSSL_ERR_ASN1_LENGTH_MISMATCH;
if( ret != 0 )
pk_free( pk );
return( ret );
}
int x509_get_sig( unsigned char **p, const unsigned char *end, x509_buf *sig )
{
int ret;
size_t len;
if( ( end - *p ) < 1 )
return( POLARSSL_ERR_X509_INVALID_SIGNATURE +
POLARSSL_ERR_ASN1_OUT_OF_DATA );
sig->tag = **p;
if( ( ret = asn1_get_bitstring_null( p, end, &len ) ) != 0 )
return( POLARSSL_ERR_X509_INVALID_SIGNATURE + ret );
sig->len = len;
sig->p = *p;
*p += len;
return( 0 );
}
/*
* Parse a SEC1 encoded private EC key
*/
static int pk_parse_key_sec1_der( ecp_keypair *eck,
const unsigned char *key,
size_t keylen )
{
int ret;
int version, pubkey_done;
size_t len;
asn1_buf params;
unsigned char *p = (unsigned char *) key;
unsigned char *end = p + keylen;
unsigned char *end2;
/*
* RFC 5915, or SEC1 Appendix C.4
*
* ECPrivateKey ::= SEQUENCE {
* version INTEGER { ecPrivkeyVer1(1) } (ecPrivkeyVer1),
* privateKey OCTET STRING,
* parameters [0] ECParameters {{ NamedCurve }} OPTIONAL,
* publicKey [1] BIT STRING OPTIONAL
* }
*/
if( ( ret = asn1_get_tag( &p, end, &len,
ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
{
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
}
end = p + len;
if( ( ret = asn1_get_int( &p, end, &version ) ) != 0 )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
if( version != 1 )
return( POLARSSL_ERR_PK_KEY_INVALID_VERSION );
if( ( ret = asn1_get_tag( &p, end, &len, ASN1_OCTET_STRING ) ) != 0 )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
if( ( ret = shmpi_read_binary( &eck->d, p, len ) ) != 0 )
{
ecp_keypair_free( eck );
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
}
p += len;
pubkey_done = 0;
if( p != end )
{
/*
* Is 'parameters' present?
*/
if( ( ret = asn1_get_tag( &p, end, &len,
ASN1_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED | 0 ) ) == 0 )
{
if( ( ret = pk_get_ecparams( &p, p + len, ¶ms) ) != 0 ||
( ret = pk_use_ecparams( ¶ms, &eck->grp ) ) != 0 )
{
ecp_keypair_free( eck );
return( ret );
}
}
else if( ret != POLARSSL_ERR_ASN1_UNEXPECTED_TAG )
{
ecp_keypair_free( eck );
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
}
/*
* Is 'publickey' present? If not, or if we can't read it (eg because it
* is compressed), create it from the private key.
*/
if( ( ret = asn1_get_tag( &p, end, &len,
ASN1_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED | 1 ) ) == 0 )
{
end2 = p + len;
if( ( ret = asn1_get_bitstring_null( &p, end2, &len ) ) != 0 )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
if( p + len != end2 )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT +
POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
if( ( ret = pk_get_ecpubkey( &p, end2, eck ) ) == 0 )
pubkey_done = 1;
else
{
/*
* The only acceptable failure mode of pk_get_ecpubkey() above
* is if the point format is not recognized.
*/
if( ret != POLARSSL_ERR_ECP_FEATURE_UNAVAILABLE )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT );
}
}
else if( ret != POLARSSL_ERR_ASN1_UNEXPECTED_TAG )
{
ecp_keypair_free( eck );
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
}
}
if( ! pubkey_done &&
( ret = ecp_mul( &eck->grp, &eck->Q, &eck->d, &eck->grp.G,
NULL, NULL ) ) != 0 )
{
ecp_keypair_free( eck );
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
}
if( ( ret = ecp_check_privkey( &eck->grp, &eck->d ) ) != 0 )
{
ecp_keypair_free( eck );
return( ret );
}
return( 0 );
}
