Fix bug in x509_get_{ecpubkey,subpubkey}()

- 'p' was not properly updated
- also add a few more checks while at it
This commit is contained in:
Manuel Pégourié-Gonnard 2013-07-10 16:07:25 +02:00 committed by Paul Bakker
parent 360a583029
commit 5b18fb04ca

View File

@ -275,17 +275,20 @@ static int x509_get_subpubkey_ec( unsigned char **p, const unsigned char *end,
return( POLARSSL_ERR_X509_KEY_INVALID_FORMAT +
POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
/*
* First byte in the content of BIT STRING is the nummber of padding bit.
* Here it is always 0 since ECPoint is an octet string, so skip it.
*/
++*p;
--len;
if( --len < 1 || *(*p)++ != 0 )
return( POLARSSL_ERR_X509_KEY_INVALID_FORMAT + ret );
if( ( ret = ecp_point_read_binary( grp, pt,
(const unsigned char *) *p, len ) ) != 0 )
{
return( POLARSSL_ERR_X509_KEY_INVALID_FORMAT + ret );
return( POLARSSL_ERR_X509_CERT_INVALID_PUBKEY );
}
*p += len;
if( ( ret = ecp_check_pubkey( grp, pt ) ) != 0 )
{
return( POLARSSL_ERR_X509_CERT_INVALID_PUBKEY );
}
return( 0 );
@ -562,7 +565,15 @@ static int x509_get_ecpubkey( unsigned char **p, const unsigned char *end,
if( ( ret = ecp_point_read_binary( &key->grp, &key->Q,
(const unsigned char *) *p, end - *p ) ) != 0 )
{
return( POLARSSL_ERR_X509_CERT_INVALID_PUBKEY + ret );
return( POLARSSL_ERR_X509_CERT_INVALID_PUBKEY );
}
*p = (unsigned char *) end;
if( ( ret = ecp_check_pubkey( &key->grp, &key->Q ) ) != 0 )
{
ecp_keypair_free( key );
return( POLARSSL_ERR_X509_CERT_INVALID_PUBKEY );
}
return( 0 );
@ -604,7 +615,7 @@ static int x509_get_pubkey( unsigned char **p,
return( POLARSSL_ERR_X509_CERT_INVALID_PUBKEY +
POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
if( *(*p)++ != 0 )
if( --len < 1 || *(*p)++ != 0 )
return( POLARSSL_ERR_X509_CERT_INVALID_PUBKEY );
if( ( ret = pk_set_type( pk, pk_alg ) ) != 0 )
@ -631,6 +642,10 @@ static int x509_get_pubkey( unsigned char **p,
break;
}
if( ret == 0 && *p != end )
ret = POLARSSL_ERR_X509_CERT_INVALID_PUBKEY
POLARSSL_ERR_ASN1_LENGTH_MISMATCH;
if( ret != 0 )
pk_free( pk );
@ -2628,6 +2643,7 @@ static int x509parse_key_sec1_der( ecp_keypair *eck,
ecp_group_id grp_id;
unsigned char *p = (unsigned char *) key;
unsigned char *end = p + keylen;
unsigned char *end2;
/*
* RFC 5915, orf SEC1 Appendix C.4
@ -2706,18 +2722,18 @@ static int x509parse_key_sec1_der( ecp_keypair *eck,
if( ( ret = asn1_get_tag( &p, end, &len,
ASN1_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED | 1 ) ) == 0 )
{
if( ( ret = x509_get_subpubkey_ec( &p, p + len, &eck->grp, &eck->Q ) )
end2 = p + len;
if( ( ret = x509_get_subpubkey_ec( &p, end2, &eck->grp, &eck->Q ) )
!= 0 )
{
ecp_keypair_free( eck );
return( ret );
}
if( ( ret = ecp_check_pubkey( &eck->grp, &eck->Q ) ) != 0 )
{
ecp_keypair_free( eck );
return( ret );
}
if( p != end2 )
return( POLARSSL_ERR_X509_CERT_INVALID_PUBKEY +
POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
}
else if ( ret != POLARSSL_ERR_ASN1_UNEXPECTED_TAG )
{