diff options
Diffstat (limited to 'lib/mbedtls-2.27.0/library/ecdh.c')
| -rw-r--r-- | lib/mbedtls-2.27.0/library/ecdh.c | 729 |
1 files changed, 0 insertions, 729 deletions
diff --git a/lib/mbedtls-2.27.0/library/ecdh.c b/lib/mbedtls-2.27.0/library/ecdh.c deleted file mode 100644 index 9dfa868..0000000 --- a/lib/mbedtls-2.27.0/library/ecdh.c +++ /dev/null @@ -1,729 +0,0 @@ -/* - * Elliptic curve Diffie-Hellman - * - * Copyright The Mbed TLS Contributors - * SPDX-License-Identifier: Apache-2.0 - * - * 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. - */ - -/* - * References: - * - * SEC1 http://www.secg.org/index.php?action=secg,docs_secg - * RFC 4492 - */ - -#include "common.h" - -#if defined(MBEDTLS_ECDH_C) - -#include "mbedtls/ecdh.h" -#include "mbedtls/platform_util.h" -#include "mbedtls/error.h" - -#include <string.h> - -/* Parameter validation macros based on platform_util.h */ -#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_ERROR_CORRUPTION_DETECTED; - - /* If multiplication is in progress, we already generated a privkey */ -#if defined(MBEDTLS_ECP_RESTARTABLE) - if( rs_ctx == NULL || rs_ctx->rsm == NULL ) -#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_ERROR_CORRUPTION_DETECTED; - 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 - 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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - - 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_ERROR_CORRUPTION_DETECTED; - 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_ERROR_CORRUPTION_DETECTED; - 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_ERROR_CORRUPTION_DETECTED; - - /* 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_ERROR_CORRUPTION_DETECTED; - 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_ERROR_CORRUPTION_DETECTED; -#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_ERROR_CORRUPTION_DETECTED; - 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_ERROR_CORRUPTION_DETECTED; -#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 */ |