Add ecdh_make_server_params (untested yet)

parent 63533e44
......@@ -34,11 +34,12 @@
*/
typedef struct
{
ecp_group grp; /*!< ellipitic curve used */
mpi d; /*!< our secret value */
ecp_point Q; /*!< our public value */
ecp_point Qp; /*!< peer's public value */
mpi z; /*!< shared secret */
ecp_group grp; /*!< ellipitic curve used */
mpi d; /*!< our secret value */
ecp_point Q; /*!< our public value */
ecp_point Qp; /*!< peer's public value */
mpi z; /*!< shared secret */
int point_format; /*!< format for point export */
}
ecdh_context;
......@@ -90,6 +91,25 @@ void ecdh_init( ecdh_context *ctx );
*/
void ecdh_free( ecdh_context *ctx );
/**
* \brief Setup and write the ServerKeyExhange parameters
*
* \param ctx ECDH context
* \param buf destination buffer
* \param olen number of chars written
* \param f_rng RNG function
* \param p_rng RNG parameter
*
* \note This function assumes that ctx->grp has already been
* properly set (for example using ecp_use_known_dp).
*
* \return 0 if successful, or an POLARSSL_ERR_ECP_XXX error code
*/
int ecdh_make_server_params( ecdh_context *ctx, size_t *olen,
unsigned char *buf, size_t blen,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng );
/**
* \brief Checkup routine
*
......
......@@ -85,9 +85,9 @@ void ecdh_init( ecdh_context *ctx )
ecp_point_init( &ctx->Q );
ecp_point_init( &ctx->Qp );
mpi_init ( &ctx->z );
ctx->point_format = POLARSSL_ECP_PF_UNCOMPRESSED;
}
/*
* Free context
*/
......@@ -103,6 +103,40 @@ void ecdh_free( ecdh_context *ctx )
mpi_free ( &ctx->z );
}
/*
* Setup and write the ServerKeyExhange parameters
* struct {
* ECParameters curve_params;
* ECPoint public;
* } ServerECDHParams;
*/
int ecdh_make_server_params( ecdh_context *ctx, size_t *olen,
unsigned char *buf, size_t blen,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng )
{
int ret;
size_t grp_len, pt_len;
if( ( ret = ecdh_gen_public( &ctx->grp, &ctx->d, &ctx->Q, f_rng, p_rng ) )
!= 0 )
return( ret );
if( ( ret = ecp_tls_write_group( &ctx->grp, &grp_len, buf, blen ) )
!= 0 )
return( ret );
buf += grp_len;
blen -= grp_len;
if( ( ret = ecp_tls_write_point( &ctx->grp, &ctx->Q, ctx->point_format,
&pt_len, buf, blen ) ) != 0 )
return( ret );
*olen = grp_len + pt_len;
return 0;
}
#if defined(POLARSSL_SELF_TEST)
......
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