ECDH: Make the implementation use the new context

The functionality from public API functions are moved to
`xxx_internal()` functions. The public API functions are modified to do
basic parameter validation and dispatch the call to the right
implementation.

There is no intended change in behaviour when
`MBEDTLS_ECDH_LEGACY_CONTEXT` is enabled.
This commit is contained in:
Janos Follath 2018-08-13 15:54:22 +01:00
parent 52735ef2fe
commit 5a3e1bfda0

View file

@ -38,6 +38,10 @@
#include <string.h>
#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
typedef mbedtls_ecdh_context mbedtls_ecdh_context_mbed;
#endif
#if !defined(MBEDTLS_ECDH_GEN_PUBLIC_ALT)
/*
* Generate public key (restartable version)
@ -124,38 +128,48 @@ int mbedtls_ecdh_compute_shared( mbedtls_ecp_group *grp, mbedtls_mpi *z,
}
#endif /* !MBEDTLS_ECDH_COMPUTE_SHARED_ALT */
/*
* Initialize context
*/
void mbedtls_ecdh_init( mbedtls_ecdh_context *ctx )
static void ecdh_init_internal( mbedtls_ecdh_context_mbed *ctx )
{
mbedtls_ecp_group_init( &ctx->grp );
mbedtls_mpi_init( &ctx->d );
mbedtls_ecp_point_init( &ctx->Q );
mbedtls_ecp_point_init( &ctx->Qp );
mbedtls_mpi_init( &ctx->z );
ctx->point_format = MBEDTLS_ECP_PF_UNCOMPRESSED;
mbedtls_ecp_point_init( &ctx->Vi );
mbedtls_ecp_point_init( &ctx->Vf );
mbedtls_mpi_init( &ctx->_d );
#if defined(MBEDTLS_ECP_RESTARTABLE)
ctx->restart_enabled = 0;
mbedtls_ecp_restart_init( &ctx->rs );
#endif
}
/*
* Setup context
* Initialize context
*/
int mbedtls_ecdh_setup( mbedtls_ecdh_context *ctx, mbedtls_ecp_group_id grp_id )
void mbedtls_ecdh_init( mbedtls_ecdh_context *ctx )
{
#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
ecdh_init_internal( ctx );
mbedtls_ecp_point_init( &ctx->Vi );
mbedtls_ecp_point_init( &ctx->Vf );
mbedtls_mpi_init( &ctx->_d );
#else
memset( ctx, 0, sizeof( mbedtls_ecdh_context ) );
ctx->var = MBEDTLS_ECDH_VARIANT_NONE;
#endif
ctx->point_format = MBEDTLS_ECP_PF_UNCOMPRESSED;
#if defined(MBEDTLS_ECP_RESTARTABLE)
ctx->restart_enabled = 0;
#endif
}
static int ecdh_setup_internal( mbedtls_ecdh_context_mbed *ctx,
mbedtls_ecp_group_id grp_id )
{
int ret;
ret = mbedtls_ecp_group_load( &ctx->grp, grp_id );
if( ret != 0 )
{
mbedtls_ecdh_free( ctx );
return( MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE );
}
@ -163,21 +177,35 @@ int mbedtls_ecdh_setup( mbedtls_ecdh_context *ctx, mbedtls_ecp_group_id grp_id )
}
/*
* Free context
* Setup context
*/
void mbedtls_ecdh_free( mbedtls_ecdh_context *ctx )
int mbedtls_ecdh_setup( mbedtls_ecdh_context *ctx, mbedtls_ecp_group_id grp_id )
{
if( ctx == NULL )
return;
return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
return( ecdh_setup_internal( ctx, grp_id ) );
#else
switch( grp_id )
{
default:
ctx->point_format = MBEDTLS_ECP_PF_UNCOMPRESSED;
ctx->var = MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0;
ctx->grp_id = grp_id;
ecdh_init_internal( &ctx->ctx.mbed_ecdh );
return( ecdh_setup_internal( &ctx->ctx.mbed_ecdh, grp_id ) );
}
#endif
}
static void ecdh_free_internal( mbedtls_ecdh_context_mbed *ctx )
{
mbedtls_ecp_group_free( &ctx->grp );
mbedtls_mpi_free( &ctx->d );
mbedtls_ecp_point_free( &ctx->Q );
mbedtls_ecp_point_free( &ctx->Qp );
mbedtls_mpi_free( &ctx->z );
mbedtls_ecp_point_free( &ctx->Vi );
mbedtls_ecp_point_free( &ctx->Vf );
mbedtls_mpi_free( &ctx->_d );
#if defined(MBEDTLS_ECP_RESTARTABLE)
mbedtls_ecp_restart_free( &ctx->rs );
@ -190,21 +218,50 @@ void mbedtls_ecdh_free( mbedtls_ecdh_context *ctx )
*/
void mbedtls_ecdh_enable_restart( mbedtls_ecdh_context *ctx )
{
if( ctx == NULL )
return;
ctx->restart_enabled = 1;
}
#endif
/*
* Setup and write the ServerKeyExhange parameters (RFC 4492)
* struct {
* ECParameters curve_params;
* ECPoint public;
* } ServerECDHParams;
* Free context
*/
int mbedtls_ecdh_make_params( mbedtls_ecdh_context *ctx, size_t *olen,
unsigned char *buf, size_t blen,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng )
void mbedtls_ecdh_free( mbedtls_ecdh_context *ctx )
{
if( ctx == NULL )
return;
#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
mbedtls_ecp_point_free( &ctx->Vi );
mbedtls_ecp_point_free( &ctx->Vf );
mbedtls_mpi_free( &ctx->_d );
ecdh_free_internal( ctx );
#else
switch( ctx->var )
{
case MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0:
ecdh_free_internal( &ctx->ctx.mbed_ecdh );
break;
default:
break;
}
ctx->point_format = MBEDTLS_ECP_PF_UNCOMPRESSED;
ctx->var = MBEDTLS_ECDH_VARIANT_NONE;
ctx->grp_id = MBEDTLS_ECP_DP_NONE;
#endif
}
static int ecdh_make_params_internal( mbedtls_ecdh_context_mbed *ctx,
size_t *olen, int point_format,
unsigned char *buf, size_t blen,
int (*f_rng)(void *,
unsigned char *,
size_t),
void *p_rng,
int restart_enabled )
{
int ret;
size_t grp_len, pt_len;
@ -212,12 +269,14 @@ int mbedtls_ecdh_make_params( mbedtls_ecdh_context *ctx, size_t *olen,
mbedtls_ecp_restart_ctx *rs_ctx = NULL;
#endif
if( ctx == NULL || ctx->grp.pbits == 0 )
if( ctx->grp.pbits == 0 )
return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
#if defined(MBEDTLS_ECP_RESTARTABLE)
if( ctx->restart_enabled )
if( restart_enabled )
rs_ctx = &ctx->rs;
#else
(void) restart_enabled;
#endif
@ -231,14 +290,14 @@ int mbedtls_ecdh_make_params( mbedtls_ecdh_context *ctx, size_t *olen,
return( ret );
#endif /* MBEDTLS_ECP_RESTARTABLE */
if( ( ret = mbedtls_ecp_tls_write_group( &ctx->grp, &grp_len, buf, blen ) )
!= 0 )
if( ( ret = mbedtls_ecp_tls_write_group( &ctx->grp, &grp_len, buf,
blen ) ) != 0 )
return( ret );
buf += grp_len;
blen -= grp_len;
if( ( ret = mbedtls_ecp_tls_write_point( &ctx->grp, &ctx->Q, ctx->point_format,
if( ( ret = mbedtls_ecp_tls_write_point( &ctx->grp, &ctx->Q, point_format,
&pt_len, buf, blen ) ) != 0 )
return( ret );
@ -246,6 +305,54 @@ int mbedtls_ecdh_make_params( mbedtls_ecdh_context *ctx, size_t *olen,
return( 0 );
}
/*
* Setup and write the ServerKeyExhange parameters (RFC 4492)
* struct {
* ECParameters curve_params;
* ECPoint public;
* } ServerECDHParams;
*/
int mbedtls_ecdh_make_params( mbedtls_ecdh_context *ctx, size_t *olen,
unsigned char *buf, size_t blen,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng )
{
int restart_enabled = 0;
if( ctx == NULL )
return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
#if defined(MBEDTLS_ECP_RESTARTABLE)
restart_enabled = ctx->restart_enabled;
#else
(void) restart_enabled;
#endif
#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
return( ecdh_make_params_internal( ctx, olen, ctx->point_format, buf, blen,
f_rng, p_rng, restart_enabled ) );
#else
switch( ctx->var )
{
case MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0:
return( ecdh_make_params_internal( &ctx->ctx.mbed_ecdh, olen,
ctx->point_format, buf, blen,
f_rng, p_rng,
restart_enabled ) );
default:
return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
}
#endif
}
static int ecdh_read_params_internal( mbedtls_ecdh_context_mbed *ctx,
const unsigned char **buf,
const unsigned char *end )
{
return( mbedtls_ecp_tls_read_point( &ctx->grp, &ctx->Qp, buf,
end - *buf ) );
}
/*
* Read the ServerKeyExhange parameters (RFC 4492)
* struct {
@ -254,11 +361,15 @@ int mbedtls_ecdh_make_params( mbedtls_ecdh_context *ctx, size_t *olen,
* } ServerECDHParams;
*/
int mbedtls_ecdh_read_params( mbedtls_ecdh_context *ctx,
const unsigned char **buf, const unsigned char *end )
const unsigned char **buf,
const unsigned char *end )
{
int ret;
mbedtls_ecp_group_id grp_id;
if( ctx == NULL )
return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
if( ( ret = mbedtls_ecp_tls_read_group_id( &grp_id, buf, end - *buf ) )
!= 0 )
return( ret );
@ -266,24 +377,26 @@ int mbedtls_ecdh_read_params( mbedtls_ecdh_context *ctx,
if( ( ret = mbedtls_ecdh_setup( ctx, grp_id ) ) != 0 )
return( ret );
if( ( ret = mbedtls_ecp_tls_read_point( &ctx->grp, &ctx->Qp, buf,
end - *buf ) ) != 0 )
return( ret );
return( 0 );
#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
return( ecdh_read_params_internal( ctx, buf, end ) );
#else
switch( ctx->var )
{
case MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0:
return( ecdh_read_params_internal( &ctx->ctx.mbed_ecdh,
buf, end ) );
default:
return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
}
#endif
}
/*
* Get parameters from a keypair
*/
int mbedtls_ecdh_get_params( mbedtls_ecdh_context *ctx, const mbedtls_ecp_keypair *key,
mbedtls_ecdh_side side )
static int ecdh_get_params_internal( mbedtls_ecdh_context_mbed *ctx,
const mbedtls_ecp_keypair *key,
mbedtls_ecdh_side side )
{
int ret;
if( ( ret = mbedtls_ecdh_setup( ctx, key->grp.id ) ) != 0 )
return( ret );
/* If it's not our key, just import the public part as Qp */
if( side == MBEDTLS_ECDH_THEIRS )
return( mbedtls_ecp_copy( &ctx->Qp, &key->Q ) );
@ -300,29 +413,61 @@ int mbedtls_ecdh_get_params( mbedtls_ecdh_context *ctx, const mbedtls_ecp_keypai
}
/*
* Setup and export the client public value
* Get parameters from a keypair
*/
int mbedtls_ecdh_make_public( mbedtls_ecdh_context *ctx, size_t *olen,
unsigned char *buf, size_t blen,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng )
int mbedtls_ecdh_get_params( mbedtls_ecdh_context *ctx,
const mbedtls_ecp_keypair *key,
mbedtls_ecdh_side side )
{
int ret;
if( ctx == NULL )
return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
if( ( ret = mbedtls_ecdh_setup( ctx, key->grp.id ) ) != 0 )
return( ret );
#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
return( ecdh_get_params_internal( ctx, key, side ) );
#else
switch( ctx->var )
{
case MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0:
return( ecdh_get_params_internal( &ctx->ctx.mbed_ecdh,
key, side ) );
default:
return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
}
#endif
}
static int ecdh_make_public_internal( mbedtls_ecdh_context_mbed *ctx,
size_t *olen, int point_format,
unsigned char *buf, size_t blen,
int (*f_rng)(void *,
unsigned char *,
size_t),
void *p_rng,
int restart_enabled )
{
int ret;
#if defined(MBEDTLS_ECP_RESTARTABLE)
mbedtls_ecp_restart_ctx *rs_ctx = NULL;
#endif
if( ctx == NULL || ctx->grp.pbits == 0 )
if( ctx->grp.pbits == 0 )
return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
#if defined(MBEDTLS_ECP_RESTARTABLE)
if( ctx->restart_enabled )
if( restart_enabled )
rs_ctx = &ctx->rs;
#else
(void) restart_enabled;
#endif
#if defined(MBEDTLS_ECP_RESTARTABLE)
if( ( ret = ecdh_gen_public_restartable( &ctx->grp, &ctx->d, &ctx->Q,
f_rng, p_rng, rs_ctx ) ) != 0 )
f_rng, p_rng, rs_ctx ) ) != 0 )
return( ret );
#else
if( ( ret = mbedtls_ecdh_gen_public( &ctx->grp, &ctx->d, &ctx->Q,
@ -330,23 +475,52 @@ int mbedtls_ecdh_make_public( mbedtls_ecdh_context *ctx, size_t *olen,
return( ret );
#endif /* MBEDTLS_ECP_RESTARTABLE */
return mbedtls_ecp_tls_write_point( &ctx->grp, &ctx->Q, ctx->point_format,
olen, buf, blen );
return mbedtls_ecp_tls_write_point( &ctx->grp, &ctx->Q, point_format, olen,
buf, blen );
}
/*
* Parse and import the client's public value
* Setup and export the client public value
*/
int mbedtls_ecdh_read_public( mbedtls_ecdh_context *ctx,
const unsigned char *buf, size_t blen )
int mbedtls_ecdh_make_public( mbedtls_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;
const unsigned char *p = buf;
int restart_enabled = 0;
if( ctx == NULL )
return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
if( ( ret = mbedtls_ecp_tls_read_point( &ctx->grp, &ctx->Qp, &p, blen ) ) != 0 )
#if defined(MBEDTLS_ECP_RESTARTABLE)
restart_enabled = ctx->restart_enabled;
#endif
#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
return( ecdh_make_public_internal( ctx, olen, ctx->point_format, buf, blen,
f_rng, p_rng, restart_enabled ) );
#else
switch( ctx->var )
{
case MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0:
return( ecdh_make_public_internal( &ctx->ctx.mbed_ecdh, olen,
ctx->point_format, buf, blen,
f_rng, p_rng,
restart_enabled ) );
default:
return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
}
#endif
}
static int ecdh_read_public_internal( mbedtls_ecdh_context_mbed *ctx,
const unsigned char *buf, size_t blen )
{
int ret;
const unsigned char *p = buf;
if( ( ret = mbedtls_ecp_tls_read_point( &ctx->grp, &ctx->Qp, &p,
blen ) ) != 0 )
return( ret );
if( (size_t)( p - buf ) != blen )
@ -356,12 +530,36 @@ int mbedtls_ecdh_read_public( mbedtls_ecdh_context *ctx,
}
/*
* Derive and export the shared secret
* Parse and import the client's public value
*/
int mbedtls_ecdh_calc_secret( mbedtls_ecdh_context *ctx, size_t *olen,
unsigned char *buf, size_t blen,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng )
int mbedtls_ecdh_read_public( mbedtls_ecdh_context *ctx,
const unsigned char *buf, size_t blen )
{
if( ctx == NULL )
return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
return( ecdh_read_public_internal( ctx, buf, blen ) );
#else
switch( ctx->var )
{
case MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0:
return( ecdh_read_public_internal( &ctx->ctx.mbed_ecdh,
buf, blen ) );
default:
return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
}
#endif
}
static int ecdh_calc_secret_internal( mbedtls_ecdh_context_mbed *ctx,
size_t *olen, unsigned char *buf,
size_t blen,
int (*f_rng)(void *,
unsigned char *,
size_t),
void *p_rng,
int restart_enabled )
{
int ret;
#if defined(MBEDTLS_ECP_RESTARTABLE)
@ -372,13 +570,16 @@ int mbedtls_ecdh_calc_secret( mbedtls_ecdh_context *ctx, size_t *olen,
return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
#if defined(MBEDTLS_ECP_RESTARTABLE)
if( ctx->restart_enabled )
if( restart_enabled )
rs_ctx = &ctx->rs;
#else
(void) restart_enabled;
#endif
#if defined(MBEDTLS_ECP_RESTARTABLE)
if( ( ret = ecdh_compute_shared_restartable( &ctx->grp,
&ctx->z, &ctx->Qp, &ctx->d, f_rng, p_rng, rs_ctx ) ) != 0 )
if( ( ret = ecdh_compute_shared_restartable( &ctx->grp, &ctx->z, &ctx->Qp,
&ctx->d, f_rng, p_rng,
rs_ctx ) ) != 0 )
{
return( ret );
}
@ -397,4 +598,37 @@ int mbedtls_ecdh_calc_secret( mbedtls_ecdh_context *ctx, size_t *olen,
return mbedtls_mpi_write_binary( &ctx->z, buf, *olen );
}
/*
* Derive and export the shared secret
*/
int mbedtls_ecdh_calc_secret( mbedtls_ecdh_context *ctx, size_t *olen,
unsigned char *buf, size_t blen,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng )
{
int restart_enabled = 0;
if( ctx == NULL )
return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
#if defined(MBEDTLS_ECP_RESTARTABLE)
restart_enabled = ctx->restart_enabled;
#endif
#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
return( ecdh_calc_secret_internal( ctx, olen, buf, blen, f_rng, p_rng,
restart_enabled ) );
#else
switch( ctx->var )
{
case MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0:
return( ecdh_calc_secret_internal( &ctx->ctx.mbed_ecdh, olen, buf,
blen, f_rng, p_rng,
restart_enabled ) );
default:
return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
}
#endif
}
#endif /* MBEDTLS_ECDH_C */