Add ecp_tls_write_group()

This commit is contained in:
Manuel Pégourié-Gonnard 2013-02-10 12:06:19 +01:00
parent 6282acaec2
commit b325887fad
2 changed files with 56 additions and 7 deletions

View file

@ -534,9 +534,11 @@ cleanup:
/*
* Set a group using well-known domain parameters
*/
int ecp_use_known_dp( ecp_group *grp, uint16_t index )
int ecp_use_known_dp( ecp_group *grp, ecp_group_id id )
{
switch( index )
grp->id = id;
switch( id )
{
case POLARSSL_ECP_DP_SECP192R1:
grp->modp = ecp_mod_p192;
@ -574,7 +576,7 @@ int ecp_use_known_dp( ecp_group *grp, uint16_t index )
*/
int ecp_tls_read_group( ecp_group *grp, const unsigned char *buf, size_t len )
{
uint16_t namedcurve;
ecp_group_id id;
/*
* We expect at least three bytes (see below)
@ -589,10 +591,37 @@ int ecp_tls_read_group( ecp_group *grp, const unsigned char *buf, size_t len )
return( POLARSSL_ERR_ECP_BAD_INPUT_DATA );
/*
* Next two bytes are the namedcurve
* Next two bytes are the namedcurve value
*/
namedcurve = 256 * buf[0] + buf[1];
return ecp_use_known_dp( grp, namedcurve );
id = 256 * buf[0] + buf[1];
return ecp_use_known_dp( grp, id );
}
/*
* Write the ECParameters record corresponding to a group (RFC 4492)
*/
int ecp_tls_write_group( const ecp_group *grp, size_t *olen,
unsigned char *buf, size_t blen )
{
/*
* We are going to write 3 bytes (see below)
*/
*olen = 3;
if( blen < *olen )
return( POLARSSL_ERR_ECP_BUFFER_TOO_SMALL );
/*
* First byte is curve_type, always named_curve
*/
*buf++ = POLARSSL_ECP_TLS_NAMED_CURVE;
/*
* Next two bytes are the namedcurve value
*/
buf[0] = grp->id >> 8;
buf[1] = grp->id && 0xFF;
return 0;
}
/*