cosmopolitan/third_party/mbedtls/ecdh.c
Justine Tunney 398f0c16fb Add SNI support to redbean and improve SSL perf
This change makes SSL virtual hosting possible. You can now load
multiple certificates for multiple domains and redbean will just
figure out which one to use, even if you only have 1 ip address.
You can also use a jumbo certificate that lists all your domains
in the the subject alternative names.

This change also makes performance improvements to MbedTLS. Here
are some benchmarks vs. cc1920749e

                                   BEFORE    AFTER   (microsecs)
suite_ssl.com                     2512881   191738 13.11x faster
suite_pkparse.com                   36291     3295 11.01x faster
suite_x509parse.com                854669   120293  7.10x faster
suite_pkwrite.com                    6549     1265  5.18x faster
suite_ecdsa.com                     53347    18778  2.84x faster
suite_pk.com                        49051    18717  2.62x faster
suite_ecdh.com                      19535     9502  2.06x faster
suite_shax.com                      15848     7965  1.99x faster
suite_rsa.com                      353257   184828  1.91x faster
suite_x509write.com                162646    85733  1.90x faster
suite_ecp.com                       20503    11050  1.86x faster
suite_hmac_drbg.no_reseed.com       19528    11417  1.71x faster
suite_hmac_drbg.nopr.com            12460     8010  1.56x faster
suite_mpi.com                      687124   442661  1.55x faster
suite_hmac_drbg.pr.com              11890     7752  1.53x faster

There aren't any special tricks to the performance imporvements.
It's mostly due to code cleanup, assembly and intel instructions
like mulx, adox, and adcx.
2021-07-23 13:56:13 -07:00

730 lines
24 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:4;tab-width:4;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright The Mbed TLS Contributors │
│ │
│ Licensed under the Apache License, Version 2.0 (the "License"); │
│ you may not use this file except in compliance with the License. │
│ You may obtain a copy of the License at │
│ │
│ http://www.apache.org/licenses/LICENSE-2.0 │
│ │
│ Unless required by applicable law or agreed to in writing, software │
│ distributed under the License is distributed on an "AS IS" BASIS, │
│ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. │
│ See the License for the specific language governing permissions and │
│ limitations under the License. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "third_party/mbedtls/common.h"
#include "third_party/mbedtls/ecdh.h"
#include "third_party/mbedtls/error.h"
#include "third_party/mbedtls/platform.h"
asm(".ident\t\"\\n\\n\
Mbed TLS (Apache 2.0)\\n\
Copyright ARM Limited\\n\
Copyright Mbed TLS Contributors\"");
asm(".include \"libc/disclaimer.inc\"");
/* clang-format off */
/**
* @fileoverview Elliptic curve Diffie-Hellman
*
* @see SEC1 http://www.secg.org/index.php?action=secg,docs_secg
* @see RFC4492
*/
#if defined(MBEDTLS_ECDH_C)
#define ECDH_VALIDATE_RET( cond ) \
MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_ECP_BAD_INPUT_DATA )
#define ECDH_VALIDATE( cond ) \
MBEDTLS_INTERNAL_VALIDATE( cond )
#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
typedef mbedtls_ecdh_context mbedtls_ecdh_context_mbed;
#endif
static mbedtls_ecp_group_id mbedtls_ecdh_grp_id(
const mbedtls_ecdh_context *ctx )
{
#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
return( ctx->grp.id );
#else
return( ctx->grp_id );
#endif
}
int mbedtls_ecdh_can_do( mbedtls_ecp_group_id gid )
{
/* At this time, all groups support ECDH. */
(void) gid;
return( 1 );
}
#if !defined(MBEDTLS_ECDH_GEN_PUBLIC_ALT)
/*
* Generate public key (restartable version)
*
* Note: this internal function relies on its caller preserving the value of
* the output parameter 'd' across continuation calls. This would not be
* acceptable for a public function but is OK here as we control call sites.
*/
static int ecdh_gen_public_restartable( mbedtls_ecp_group *grp,
mbedtls_mpi *d, mbedtls_ecp_point *Q,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng,
mbedtls_ecp_restart_ctx *rs_ctx )
{
int ret = MBEDTLS_ERR_THIS_CORRUPTION;
/* If multiplication is in progress, we already generated a privkey */
#if defined(MBEDTLS_ECP_RESTARTABLE)
if( !rs_ctx || !rs_ctx->rsm )
#endif
MBEDTLS_MPI_CHK( mbedtls_ecp_gen_privkey( grp, d, f_rng, p_rng ) );
MBEDTLS_MPI_CHK( mbedtls_ecp_mul_restartable( grp, Q, d, &grp->G,
f_rng, p_rng, rs_ctx ) );
cleanup:
return( ret );
}
/*
* Generate public key
*/
int mbedtls_ecdh_gen_public( mbedtls_ecp_group *grp, mbedtls_mpi *d, mbedtls_ecp_point *Q,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng )
{
ECDH_VALIDATE_RET( grp != NULL );
ECDH_VALIDATE_RET( d != NULL );
ECDH_VALIDATE_RET( Q != NULL );
ECDH_VALIDATE_RET( f_rng != NULL );
return( ecdh_gen_public_restartable( grp, d, Q, f_rng, p_rng, NULL ) );
}
#endif /* !MBEDTLS_ECDH_GEN_PUBLIC_ALT */
#if !defined(MBEDTLS_ECDH_COMPUTE_SHARED_ALT)
/*
* Compute shared secret (SEC1 3.3.1)
*/
static int ecdh_compute_shared_restartable( mbedtls_ecp_group *grp,
mbedtls_mpi *z,
const mbedtls_ecp_point *Q, const mbedtls_mpi *d,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng,
mbedtls_ecp_restart_ctx *rs_ctx )
{
int ret = MBEDTLS_ERR_THIS_CORRUPTION;
mbedtls_ecp_point P;
mbedtls_ecp_point_init( &P );
MBEDTLS_MPI_CHK( mbedtls_ecp_mul_restartable( grp, &P, d, Q,
f_rng, p_rng, rs_ctx ) );
if( mbedtls_ecp_is_zero( &P ) )
{
ret = MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
goto cleanup;
}
MBEDTLS_MPI_CHK( mbedtls_mpi_copy( z, &P.X ) );
cleanup:
mbedtls_ecp_point_free( &P );
return( ret );
}
/*
* Compute shared secret (SEC1 3.3.1)
*/
int mbedtls_ecdh_compute_shared( mbedtls_ecp_group *grp, mbedtls_mpi *z,
const mbedtls_ecp_point *Q, const mbedtls_mpi *d,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng )
{
ECDH_VALIDATE_RET( grp != NULL );
ECDH_VALIDATE_RET( Q != NULL );
ECDH_VALIDATE_RET( d != NULL );
ECDH_VALIDATE_RET( z != NULL );
return( ecdh_compute_shared_restartable( grp, z, Q, d,
f_rng, p_rng, NULL ) );
}
#endif /* !MBEDTLS_ECDH_COMPUTE_SHARED_ALT */
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 );
#if defined(MBEDTLS_ECP_RESTARTABLE)
mbedtls_ecp_restart_init( &ctx->rs );
#endif
}
/*
* Initialize context
*/
void mbedtls_ecdh_init( mbedtls_ecdh_context *ctx )
{
ECDH_VALIDATE( ctx != NULL );
#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
mbedtls_platform_zeroize( ctx, 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 = MBEDTLS_ERR_THIS_CORRUPTION;
ret = mbedtls_ecp_group_load( &ctx->grp, grp_id );
if( ret != 0 )
{
return( MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE );
}
return( 0 );
}
/*
* Setup context
*/
int mbedtls_ecdh_setup( mbedtls_ecdh_context *ctx, mbedtls_ecp_group_id grp_id )
{
ECDH_VALIDATE_RET( ctx != NULL );
#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
return( ecdh_setup_internal( ctx, grp_id ) );
#else
switch( grp_id )
{
#if defined(MBEDTLS_ECDH_VARIANT_EVEREST_ENABLED)
case MBEDTLS_ECP_DP_CURVE25519:
ctx->point_format = MBEDTLS_ECP_PF_COMPRESSED;
ctx->var = MBEDTLS_ECDH_VARIANT_EVEREST;
ctx->grp_id = grp_id;
return( mbedtls_everest_setup( &ctx->ctx.everest_ecdh, grp_id ) );
#endif
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 );
#if defined(MBEDTLS_ECP_RESTARTABLE)
mbedtls_ecp_restart_free( &ctx->rs );
#endif
}
#if defined(MBEDTLS_ECP_RESTARTABLE)
/*
* Enable restartable operations for context
*/
void mbedtls_ecdh_enable_restart( mbedtls_ecdh_context *ctx )
{
ECDH_VALIDATE( ctx != NULL );
ctx->restart_enabled = 1;
}
#endif
/*
* Free context
*/
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 )
{
#if defined(MBEDTLS_ECDH_VARIANT_EVEREST_ENABLED)
case MBEDTLS_ECDH_VARIANT_EVEREST:
mbedtls_everest_free( &ctx->ctx.everest_ecdh );
break;
#endif
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 = MBEDTLS_ERR_THIS_CORRUPTION;
size_t grp_len, pt_len;
#if defined(MBEDTLS_ECP_RESTARTABLE)
mbedtls_ecp_restart_ctx *rs_ctx = NULL;
#endif
if( ctx->grp.pbits == 0 )
return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
#if defined(MBEDTLS_ECP_RESTARTABLE)
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 )
return( ret );
#else
if( ( ret = mbedtls_ecdh_gen_public( &ctx->grp, &ctx->d, &ctx->Q,
f_rng, p_rng ) ) != 0 )
return( ret );
#endif /* MBEDTLS_ECP_RESTARTABLE */
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, point_format,
&pt_len, buf, blen ) ) != 0 )
return( ret );
*olen = grp_len + pt_len;
return( 0 );
}
/*
* Setup and write the ServerKeyExchange 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;
ECDH_VALIDATE_RET( ctx != NULL );
ECDH_VALIDATE_RET( olen != NULL );
ECDH_VALIDATE_RET( buf != NULL );
ECDH_VALIDATE_RET( f_rng != NULL );
#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 )
{
#if defined(MBEDTLS_ECDH_VARIANT_EVEREST_ENABLED)
case MBEDTLS_ECDH_VARIANT_EVEREST:
return( mbedtls_everest_make_params( &ctx->ctx.everest_ecdh, olen,
buf, blen, f_rng, p_rng ) );
#endif
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 {
* ECParameters curve_params;
* ECPoint public;
* } ServerECDHParams;
*/
int mbedtls_ecdh_read_params( mbedtls_ecdh_context *ctx,
const unsigned char **buf,
const unsigned char *end )
{
int ret = MBEDTLS_ERR_THIS_CORRUPTION;
mbedtls_ecp_group_id grp_id;
ECDH_VALIDATE_RET( ctx != NULL );
ECDH_VALIDATE_RET( buf != NULL );
ECDH_VALIDATE_RET( *buf != NULL );
ECDH_VALIDATE_RET( end != NULL );
if( ( ret = mbedtls_ecp_tls_read_group_id( &grp_id, buf, end - *buf ) )
!= 0 )
return( ret );
if( ( ret = mbedtls_ecdh_setup( ctx, grp_id ) ) != 0 )
return( ret );
#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
return( ecdh_read_params_internal( ctx, buf, end ) );
#else
switch( ctx->var )
{
#if defined(MBEDTLS_ECDH_VARIANT_EVEREST_ENABLED)
case MBEDTLS_ECDH_VARIANT_EVEREST:
return( mbedtls_everest_read_params( &ctx->ctx.everest_ecdh,
buf, end) );
#endif
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
}
static int ecdh_get_params_internal( mbedtls_ecdh_context_mbed *ctx,
const mbedtls_ecp_keypair *key,
mbedtls_ecdh_side side )
{
int ret = MBEDTLS_ERR_THIS_CORRUPTION;
/* 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 ) );
/* Our key: import public (as Q) and private parts */
if( side != MBEDTLS_ECDH_OURS )
return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
if( ( ret = mbedtls_ecp_copy( &ctx->Q, &key->Q ) ) != 0 ||
( ret = mbedtls_mpi_copy( &ctx->d, &key->d ) ) != 0 )
return( ret );
return( 0 );
}
/*
* Get parameters from a keypair
*/
int mbedtls_ecdh_get_params( mbedtls_ecdh_context *ctx,
const mbedtls_ecp_keypair *key,
mbedtls_ecdh_side side )
{
int ret = MBEDTLS_ERR_THIS_CORRUPTION;
ECDH_VALIDATE_RET( ctx != NULL );
ECDH_VALIDATE_RET( key != NULL );
ECDH_VALIDATE_RET( side == MBEDTLS_ECDH_OURS ||
side == MBEDTLS_ECDH_THEIRS );
if( mbedtls_ecdh_grp_id( ctx ) == MBEDTLS_ECP_DP_NONE )
{
/* This is the first call to get_params(). Set up the context
* for use with the group. */
if( ( ret = mbedtls_ecdh_setup( ctx, key->grp.id ) ) != 0 )
return( ret );
}
else
{
/* This is not the first call to get_params(). Check that the
* current key's group is the same as the context's, which was set
* from the first key's group. */
if( mbedtls_ecdh_grp_id( ctx ) != key->grp.id )
return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
}
#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
return( ecdh_get_params_internal( ctx, key, side ) );
#else
switch( ctx->var )
{
#if defined(MBEDTLS_ECDH_VARIANT_EVEREST_ENABLED)
case MBEDTLS_ECDH_VARIANT_EVEREST:
{
mbedtls_everest_ecdh_side s = side == MBEDTLS_ECDH_OURS ?
MBEDTLS_EVEREST_ECDH_OURS :
MBEDTLS_EVEREST_ECDH_THEIRS;
return( mbedtls_everest_get_params( &ctx->ctx.everest_ecdh,
key, s) );
}
#endif
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 = MBEDTLS_ERR_THIS_CORRUPTION;
#if defined(MBEDTLS_ECP_RESTARTABLE)
mbedtls_ecp_restart_ctx *rs_ctx = NULL;
#endif
if( ctx->grp.pbits == 0 )
return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
#if defined(MBEDTLS_ECP_RESTARTABLE)
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 )
return( ret );
#else
if( ( ret = mbedtls_ecdh_gen_public( &ctx->grp, &ctx->d, &ctx->Q,
f_rng, p_rng ) ) != 0 )
return( ret );
#endif /* MBEDTLS_ECP_RESTARTABLE */
return mbedtls_ecp_tls_write_point( &ctx->grp, &ctx->Q, point_format, olen,
buf, blen );
}
/*
* Setup and export the client public value
*/
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 restart_enabled = 0;
ECDH_VALIDATE_RET( ctx != NULL );
ECDH_VALIDATE_RET( olen != NULL );
ECDH_VALIDATE_RET( buf != NULL );
ECDH_VALIDATE_RET( f_rng != NULL );
#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 )
{
#if defined(MBEDTLS_ECDH_VARIANT_EVEREST_ENABLED)
case MBEDTLS_ECDH_VARIANT_EVEREST:
return( mbedtls_everest_make_public( &ctx->ctx.everest_ecdh, olen,
buf, blen, f_rng, p_rng ) );
#endif
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 = MBEDTLS_ERR_THIS_CORRUPTION;
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 )
return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
return( 0 );
}
/*
* Parse and import the client's public value
*/
int mbedtls_ecdh_read_public( mbedtls_ecdh_context *ctx,
const unsigned char *buf, size_t blen )
{
ECDH_VALIDATE_RET( ctx != NULL );
ECDH_VALIDATE_RET( buf != NULL );
#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
return( ecdh_read_public_internal( ctx, buf, blen ) );
#else
switch( ctx->var )
{
#if defined(MBEDTLS_ECDH_VARIANT_EVEREST_ENABLED)
case MBEDTLS_ECDH_VARIANT_EVEREST:
return( mbedtls_everest_read_public( &ctx->ctx.everest_ecdh,
buf, blen ) );
#endif
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 = MBEDTLS_ERR_THIS_CORRUPTION;
#if defined(MBEDTLS_ECP_RESTARTABLE)
mbedtls_ecp_restart_ctx *rs_ctx = NULL;
#endif
if( ctx == NULL || ctx->grp.pbits == 0 )
return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
#if defined(MBEDTLS_ECP_RESTARTABLE)
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 )
{
return( ret );
}
#else
if( ( ret = mbedtls_ecdh_compute_shared( &ctx->grp, &ctx->z, &ctx->Qp,
&ctx->d, f_rng, p_rng ) ) != 0 )
{
return( ret );
}
#endif /* MBEDTLS_ECP_RESTARTABLE */
if( mbedtls_mpi_size( &ctx->z ) > blen )
return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
*olen = ctx->grp.pbits / 8 + ( ( ctx->grp.pbits % 8 ) != 0 );
if( mbedtls_ecp_get_type( &ctx->grp ) == MBEDTLS_ECP_TYPE_MONTGOMERY )
return mbedtls_mpi_write_binary_le( &ctx->z, buf, *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;
ECDH_VALIDATE_RET( ctx != NULL );
ECDH_VALIDATE_RET( olen != NULL );
ECDH_VALIDATE_RET( buf != NULL );
#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 )
{
#if defined(MBEDTLS_ECDH_VARIANT_EVEREST_ENABLED)
case MBEDTLS_ECDH_VARIANT_EVEREST:
return( mbedtls_everest_calc_secret( &ctx->ctx.everest_ecdh, olen,
buf, blen, f_rng, p_rng ) );
#endif
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 */