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cosmopolitan/third_party/mbedtls/ecdh.c
Justine Tunney 957c61cbbf
Release Cosmopolitan v3.3 
This change upgrades to GCC 12.3 and GNU binutils 2.42. The GNU linker
appears to have changed things so that only a single de-duplicated str
table is present in the binary, and it gets placed wherever the linker
wants, regardless of what the linker script says. To cope with that we
need to stop using .ident to embed licenses. As such, this change does
significant work to revamp how third party licenses are defined in the
codebase, using `.section .notice,"aR",@progbits`.

This new GCC 12.3 toolchain has support for GNU indirect functions. It
lets us support __target_clones__ for the first time. This is used for
optimizing the performance of libc string functions such as strlen and
friends so far on x86, by ensuring AVX systems favor a second codepath
that uses VEX encoding. It shaves some latency off certain operations.
It's a useful feature to have for scientific computing for the reasons
explained by the test/libcxx/openmp_test.cc example which compiles for
fifteen different microarchitectures. Thanks to the upgrades, it's now
also possible to use newer instruction sets, such as AVX512FP16, VNNI.

Cosmo now uses the %gs register on x86 by default for TLS. Doing it is
helpful for any program that links `cosmo_dlopen()`. Such programs had
to recompile their binaries at startup to change the TLS instructions.
That's not great, since it means every page in the executable needs to
be faulted. The work of rewriting TLS-related x86 opcodes, is moved to
fixupobj.com instead. This is great news for MacOS x86 users, since we
previously needed to morph the binary every time for that platform but
now that's no longer necessary. The only platforms where we need fixup
of TLS x86 opcodes at runtime are now Windows, OpenBSD, and NetBSD. On
Windows we morph TLS to point deeper into the TIB, based on a TlsAlloc
assignment, and on OpenBSD/NetBSD we morph %gs back into %fs since the
kernels do not allow us to specify a value for the %gs register.

OpenBSD users are now required to use APE Loader to run Cosmo binaries
and assimilation is no longer possible. OpenBSD kernel needs to change
to allow programs to specify a value for the %gs register, or it needs
to stop marking executable pages loaded by the kernel as mimmutable().

This release fixes __constructor__, .ctor, .init_array, and lastly the
.preinit_array so they behave the exact same way as glibc.

We no longer use hex constants to define math.h symbols like M_PI.
2024-02-20 13:27:59 -08:00

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/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:4;tab-width:4;coding:utf-8 -*-│
│ vi: set et 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"
__static_yoink("mbedtls_notice");
/**
* @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 */
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