--- /dev/null
+/*\r
+ * Elliptic curve Diffie-Hellman\r
+ *\r
+ * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved\r
+ * SPDX-License-Identifier: Apache-2.0\r
+ *\r
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may\r
+ * not use this file except in compliance with the License.\r
+ * You may obtain a copy of the License at\r
+ *\r
+ * http://www.apache.org/licenses/LICENSE-2.0\r
+ *\r
+ * Unless required by applicable law or agreed to in writing, software\r
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT\r
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r
+ * See the License for the specific language governing permissions and\r
+ * limitations under the License.\r
+ *\r
+ * This file is part of mbed TLS (https://tls.mbed.org)\r
+ */\r
+\r
+/*\r
+ * References:\r
+ *\r
+ * SEC1 http://www.secg.org/index.php?action=secg,docs_secg\r
+ * RFC 4492\r
+ */\r
+\r
+#if !defined(MBEDTLS_CONFIG_FILE)\r
+#include "mbedtls/config.h"\r
+#else\r
+#include MBEDTLS_CONFIG_FILE\r
+#endif\r
+\r
+#if defined(MBEDTLS_ECDH_C)\r
+\r
+#include "mbedtls/ecdh.h"\r
+#include "mbedtls/platform_util.h"\r
+\r
+#include <string.h>\r
+\r
+/* Parameter validation macros based on platform_util.h */\r
+#define ECDH_VALIDATE_RET( cond ) \\r
+ MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_ECP_BAD_INPUT_DATA )\r
+#define ECDH_VALIDATE( cond ) \\r
+ MBEDTLS_INTERNAL_VALIDATE( cond )\r
+\r
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)\r
+typedef mbedtls_ecdh_context mbedtls_ecdh_context_mbed;\r
+#endif\r
+\r
+static mbedtls_ecp_group_id mbedtls_ecdh_grp_id(\r
+ const mbedtls_ecdh_context *ctx )\r
+{\r
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)\r
+ return( ctx->grp.id );\r
+#else\r
+ return( ctx->grp_id );\r
+#endif\r
+}\r
+\r
+#if !defined(MBEDTLS_ECDH_GEN_PUBLIC_ALT)\r
+/*\r
+ * Generate public key (restartable version)\r
+ *\r
+ * Note: this internal function relies on its caller preserving the value of\r
+ * the output parameter 'd' across continuation calls. This would not be\r
+ * acceptable for a public function but is OK here as we control call sites.\r
+ */\r
+static int ecdh_gen_public_restartable( mbedtls_ecp_group *grp,\r
+ mbedtls_mpi *d, mbedtls_ecp_point *Q,\r
+ int (*f_rng)(void *, unsigned char *, size_t),\r
+ void *p_rng,\r
+ mbedtls_ecp_restart_ctx *rs_ctx )\r
+{\r
+ int ret;\r
+\r
+ /* If multiplication is in progress, we already generated a privkey */\r
+#if defined(MBEDTLS_ECP_RESTARTABLE)\r
+ if( rs_ctx == NULL || rs_ctx->rsm == NULL )\r
+#endif\r
+ MBEDTLS_MPI_CHK( mbedtls_ecp_gen_privkey( grp, d, f_rng, p_rng ) );\r
+\r
+ MBEDTLS_MPI_CHK( mbedtls_ecp_mul_restartable( grp, Q, d, &grp->G,\r
+ f_rng, p_rng, rs_ctx ) );\r
+\r
+cleanup:\r
+ return( ret );\r
+}\r
+\r
+/*\r
+ * Generate public key\r
+ */\r
+int mbedtls_ecdh_gen_public( mbedtls_ecp_group *grp, mbedtls_mpi *d, mbedtls_ecp_point *Q,\r
+ int (*f_rng)(void *, unsigned char *, size_t),\r
+ void *p_rng )\r
+{\r
+ ECDH_VALIDATE_RET( grp != NULL );\r
+ ECDH_VALIDATE_RET( d != NULL );\r
+ ECDH_VALIDATE_RET( Q != NULL );\r
+ ECDH_VALIDATE_RET( f_rng != NULL );\r
+ return( ecdh_gen_public_restartable( grp, d, Q, f_rng, p_rng, NULL ) );\r
+}\r
+#endif /* !MBEDTLS_ECDH_GEN_PUBLIC_ALT */\r
+\r
+#if !defined(MBEDTLS_ECDH_COMPUTE_SHARED_ALT)\r
+/*\r
+ * Compute shared secret (SEC1 3.3.1)\r
+ */\r
+static int ecdh_compute_shared_restartable( mbedtls_ecp_group *grp,\r
+ mbedtls_mpi *z,\r
+ const mbedtls_ecp_point *Q, const mbedtls_mpi *d,\r
+ int (*f_rng)(void *, unsigned char *, size_t),\r
+ void *p_rng,\r
+ mbedtls_ecp_restart_ctx *rs_ctx )\r
+{\r
+ int ret;\r
+ mbedtls_ecp_point P;\r
+\r
+ mbedtls_ecp_point_init( &P );\r
+\r
+ MBEDTLS_MPI_CHK( mbedtls_ecp_mul_restartable( grp, &P, d, Q,\r
+ f_rng, p_rng, rs_ctx ) );\r
+\r
+ if( mbedtls_ecp_is_zero( &P ) )\r
+ {\r
+ ret = MBEDTLS_ERR_ECP_BAD_INPUT_DATA;\r
+ goto cleanup;\r
+ }\r
+\r
+ MBEDTLS_MPI_CHK( mbedtls_mpi_copy( z, &P.X ) );\r
+\r
+cleanup:\r
+ mbedtls_ecp_point_free( &P );\r
+\r
+ return( ret );\r
+}\r
+\r
+/*\r
+ * Compute shared secret (SEC1 3.3.1)\r
+ */\r
+int mbedtls_ecdh_compute_shared( mbedtls_ecp_group *grp, mbedtls_mpi *z,\r
+ const mbedtls_ecp_point *Q, const mbedtls_mpi *d,\r
+ int (*f_rng)(void *, unsigned char *, size_t),\r
+ void *p_rng )\r
+{\r
+ ECDH_VALIDATE_RET( grp != NULL );\r
+ ECDH_VALIDATE_RET( Q != NULL );\r
+ ECDH_VALIDATE_RET( d != NULL );\r
+ ECDH_VALIDATE_RET( z != NULL );\r
+ return( ecdh_compute_shared_restartable( grp, z, Q, d,\r
+ f_rng, p_rng, NULL ) );\r
+}\r
+#endif /* !MBEDTLS_ECDH_COMPUTE_SHARED_ALT */\r
+\r
+static void ecdh_init_internal( mbedtls_ecdh_context_mbed *ctx )\r
+{\r
+ mbedtls_ecp_group_init( &ctx->grp );\r
+ mbedtls_mpi_init( &ctx->d );\r
+ mbedtls_ecp_point_init( &ctx->Q );\r
+ mbedtls_ecp_point_init( &ctx->Qp );\r
+ mbedtls_mpi_init( &ctx->z );\r
+\r
+#if defined(MBEDTLS_ECP_RESTARTABLE)\r
+ mbedtls_ecp_restart_init( &ctx->rs );\r
+#endif\r
+}\r
+\r
+/*\r
+ * Initialize context\r
+ */\r
+void mbedtls_ecdh_init( mbedtls_ecdh_context *ctx )\r
+{\r
+ ECDH_VALIDATE( ctx != NULL );\r
+\r
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)\r
+ ecdh_init_internal( ctx );\r
+ mbedtls_ecp_point_init( &ctx->Vi );\r
+ mbedtls_ecp_point_init( &ctx->Vf );\r
+ mbedtls_mpi_init( &ctx->_d );\r
+#else\r
+ memset( ctx, 0, sizeof( mbedtls_ecdh_context ) );\r
+\r
+ ctx->var = MBEDTLS_ECDH_VARIANT_NONE;\r
+#endif\r
+ ctx->point_format = MBEDTLS_ECP_PF_UNCOMPRESSED;\r
+#if defined(MBEDTLS_ECP_RESTARTABLE)\r
+ ctx->restart_enabled = 0;\r
+#endif\r
+}\r
+\r
+static int ecdh_setup_internal( mbedtls_ecdh_context_mbed *ctx,\r
+ mbedtls_ecp_group_id grp_id )\r
+{\r
+ int ret;\r
+\r
+ ret = mbedtls_ecp_group_load( &ctx->grp, grp_id );\r
+ if( ret != 0 )\r
+ {\r
+ return( MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE );\r
+ }\r
+\r
+ return( 0 );\r
+}\r
+\r
+/*\r
+ * Setup context\r
+ */\r
+int mbedtls_ecdh_setup( mbedtls_ecdh_context *ctx, mbedtls_ecp_group_id grp_id )\r
+{\r
+ ECDH_VALIDATE_RET( ctx != NULL );\r
+\r
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)\r
+ return( ecdh_setup_internal( ctx, grp_id ) );\r
+#else\r
+ switch( grp_id )\r
+ {\r
+ default:\r
+ ctx->point_format = MBEDTLS_ECP_PF_UNCOMPRESSED;\r
+ ctx->var = MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0;\r
+ ctx->grp_id = grp_id;\r
+ ecdh_init_internal( &ctx->ctx.mbed_ecdh );\r
+ return( ecdh_setup_internal( &ctx->ctx.mbed_ecdh, grp_id ) );\r
+ }\r
+#endif\r
+}\r
+\r
+static void ecdh_free_internal( mbedtls_ecdh_context_mbed *ctx )\r
+{\r
+ mbedtls_ecp_group_free( &ctx->grp );\r
+ mbedtls_mpi_free( &ctx->d );\r
+ mbedtls_ecp_point_free( &ctx->Q );\r
+ mbedtls_ecp_point_free( &ctx->Qp );\r
+ mbedtls_mpi_free( &ctx->z );\r
+\r
+#if defined(MBEDTLS_ECP_RESTARTABLE)\r
+ mbedtls_ecp_restart_free( &ctx->rs );\r
+#endif\r
+}\r
+\r
+#if defined(MBEDTLS_ECP_RESTARTABLE)\r
+/*\r
+ * Enable restartable operations for context\r
+ */\r
+void mbedtls_ecdh_enable_restart( mbedtls_ecdh_context *ctx )\r
+{\r
+ ECDH_VALIDATE( ctx != NULL );\r
+\r
+ ctx->restart_enabled = 1;\r
+}\r
+#endif\r
+\r
+/*\r
+ * Free context\r
+ */\r
+void mbedtls_ecdh_free( mbedtls_ecdh_context *ctx )\r
+{\r
+ if( ctx == NULL )\r
+ return;\r
+\r
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)\r
+ mbedtls_ecp_point_free( &ctx->Vi );\r
+ mbedtls_ecp_point_free( &ctx->Vf );\r
+ mbedtls_mpi_free( &ctx->_d );\r
+ ecdh_free_internal( ctx );\r
+#else\r
+ switch( ctx->var )\r
+ {\r
+ case MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0:\r
+ ecdh_free_internal( &ctx->ctx.mbed_ecdh );\r
+ break;\r
+ default:\r
+ break;\r
+ }\r
+\r
+ ctx->point_format = MBEDTLS_ECP_PF_UNCOMPRESSED;\r
+ ctx->var = MBEDTLS_ECDH_VARIANT_NONE;\r
+ ctx->grp_id = MBEDTLS_ECP_DP_NONE;\r
+#endif\r
+}\r
+\r
+static int ecdh_make_params_internal( mbedtls_ecdh_context_mbed *ctx,\r
+ size_t *olen, int point_format,\r
+ unsigned char *buf, size_t blen,\r
+ int (*f_rng)(void *,\r
+ unsigned char *,\r
+ size_t),\r
+ void *p_rng,\r
+ int restart_enabled )\r
+{\r
+ int ret;\r
+ size_t grp_len, pt_len;\r
+#if defined(MBEDTLS_ECP_RESTARTABLE)\r
+ mbedtls_ecp_restart_ctx *rs_ctx = NULL;\r
+#endif\r
+\r
+ if( ctx->grp.pbits == 0 )\r
+ return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );\r
+\r
+#if defined(MBEDTLS_ECP_RESTARTABLE)\r
+ if( restart_enabled )\r
+ rs_ctx = &ctx->rs;\r
+#else\r
+ (void) restart_enabled;\r
+#endif\r
+\r
+\r
+#if defined(MBEDTLS_ECP_RESTARTABLE)\r
+ if( ( ret = ecdh_gen_public_restartable( &ctx->grp, &ctx->d, &ctx->Q,\r
+ f_rng, p_rng, rs_ctx ) ) != 0 )\r
+ return( ret );\r
+#else\r
+ if( ( ret = mbedtls_ecdh_gen_public( &ctx->grp, &ctx->d, &ctx->Q,\r
+ f_rng, p_rng ) ) != 0 )\r
+ return( ret );\r
+#endif /* MBEDTLS_ECP_RESTARTABLE */\r
+\r
+ if( ( ret = mbedtls_ecp_tls_write_group( &ctx->grp, &grp_len, buf,\r
+ blen ) ) != 0 )\r
+ return( ret );\r
+\r
+ buf += grp_len;\r
+ blen -= grp_len;\r
+\r
+ if( ( ret = mbedtls_ecp_tls_write_point( &ctx->grp, &ctx->Q, point_format,\r
+ &pt_len, buf, blen ) ) != 0 )\r
+ return( ret );\r
+\r
+ *olen = grp_len + pt_len;\r
+ return( 0 );\r
+}\r
+\r
+/*\r
+ * Setup and write the ServerKeyExhange parameters (RFC 4492)\r
+ * struct {\r
+ * ECParameters curve_params;\r
+ * ECPoint public;\r
+ * } ServerECDHParams;\r
+ */\r
+int mbedtls_ecdh_make_params( mbedtls_ecdh_context *ctx, size_t *olen,\r
+ unsigned char *buf, size_t blen,\r
+ int (*f_rng)(void *, unsigned char *, size_t),\r
+ void *p_rng )\r
+{\r
+ int restart_enabled = 0;\r
+ ECDH_VALIDATE_RET( ctx != NULL );\r
+ ECDH_VALIDATE_RET( olen != NULL );\r
+ ECDH_VALIDATE_RET( buf != NULL );\r
+ ECDH_VALIDATE_RET( f_rng != NULL );\r
+\r
+#if defined(MBEDTLS_ECP_RESTARTABLE)\r
+ restart_enabled = ctx->restart_enabled;\r
+#else\r
+ (void) restart_enabled;\r
+#endif\r
+\r
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)\r
+ return( ecdh_make_params_internal( ctx, olen, ctx->point_format, buf, blen,\r
+ f_rng, p_rng, restart_enabled ) );\r
+#else\r
+ switch( ctx->var )\r
+ {\r
+ case MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0:\r
+ return( ecdh_make_params_internal( &ctx->ctx.mbed_ecdh, olen,\r
+ ctx->point_format, buf, blen,\r
+ f_rng, p_rng,\r
+ restart_enabled ) );\r
+ default:\r
+ return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;\r
+ }\r
+#endif\r
+}\r
+\r
+static int ecdh_read_params_internal( mbedtls_ecdh_context_mbed *ctx,\r
+ const unsigned char **buf,\r
+ const unsigned char *end )\r
+{\r
+ return( mbedtls_ecp_tls_read_point( &ctx->grp, &ctx->Qp, buf,\r
+ end - *buf ) );\r
+}\r
+\r
+/*\r
+ * Read the ServerKeyExhange parameters (RFC 4492)\r
+ * struct {\r
+ * ECParameters curve_params;\r
+ * ECPoint public;\r
+ * } ServerECDHParams;\r
+ */\r
+int mbedtls_ecdh_read_params( mbedtls_ecdh_context *ctx,\r
+ const unsigned char **buf,\r
+ const unsigned char *end )\r
+{\r
+ int ret;\r
+ mbedtls_ecp_group_id grp_id;\r
+ ECDH_VALIDATE_RET( ctx != NULL );\r
+ ECDH_VALIDATE_RET( buf != NULL );\r
+ ECDH_VALIDATE_RET( *buf != NULL );\r
+ ECDH_VALIDATE_RET( end != NULL );\r
+\r
+ if( ( ret = mbedtls_ecp_tls_read_group_id( &grp_id, buf, end - *buf ) )\r
+ != 0 )\r
+ return( ret );\r
+\r
+ if( ( ret = mbedtls_ecdh_setup( ctx, grp_id ) ) != 0 )\r
+ return( ret );\r
+\r
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)\r
+ return( ecdh_read_params_internal( ctx, buf, end ) );\r
+#else\r
+ switch( ctx->var )\r
+ {\r
+ case MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0:\r
+ return( ecdh_read_params_internal( &ctx->ctx.mbed_ecdh,\r
+ buf, end ) );\r
+ default:\r
+ return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;\r
+ }\r
+#endif\r
+}\r
+\r
+static int ecdh_get_params_internal( mbedtls_ecdh_context_mbed *ctx,\r
+ const mbedtls_ecp_keypair *key,\r
+ mbedtls_ecdh_side side )\r
+{\r
+ int ret;\r
+\r
+ /* If it's not our key, just import the public part as Qp */\r
+ if( side == MBEDTLS_ECDH_THEIRS )\r
+ return( mbedtls_ecp_copy( &ctx->Qp, &key->Q ) );\r
+\r
+ /* Our key: import public (as Q) and private parts */\r
+ if( side != MBEDTLS_ECDH_OURS )\r
+ return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );\r
+\r
+ if( ( ret = mbedtls_ecp_copy( &ctx->Q, &key->Q ) ) != 0 ||\r
+ ( ret = mbedtls_mpi_copy( &ctx->d, &key->d ) ) != 0 )\r
+ return( ret );\r
+\r
+ return( 0 );\r
+}\r
+\r
+/*\r
+ * Get parameters from a keypair\r
+ */\r
+int mbedtls_ecdh_get_params( mbedtls_ecdh_context *ctx,\r
+ const mbedtls_ecp_keypair *key,\r
+ mbedtls_ecdh_side side )\r
+{\r
+ int ret;\r
+ ECDH_VALIDATE_RET( ctx != NULL );\r
+ ECDH_VALIDATE_RET( key != NULL );\r
+ ECDH_VALIDATE_RET( side == MBEDTLS_ECDH_OURS ||\r
+ side == MBEDTLS_ECDH_THEIRS );\r
+\r
+ if( mbedtls_ecdh_grp_id( ctx ) == MBEDTLS_ECP_DP_NONE )\r
+ {\r
+ /* This is the first call to get_params(). Set up the context\r
+ * for use with the group. */\r
+ if( ( ret = mbedtls_ecdh_setup( ctx, key->grp.id ) ) != 0 )\r
+ return( ret );\r
+ }\r
+ else\r
+ {\r
+ /* This is not the first call to get_params(). Check that the\r
+ * current key's group is the same as the context's, which was set\r
+ * from the first key's group. */\r
+ if( mbedtls_ecdh_grp_id( ctx ) != key->grp.id )\r
+ return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );\r
+ }\r
+\r
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)\r
+ return( ecdh_get_params_internal( ctx, key, side ) );\r
+#else\r
+ switch( ctx->var )\r
+ {\r
+ case MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0:\r
+ return( ecdh_get_params_internal( &ctx->ctx.mbed_ecdh,\r
+ key, side ) );\r
+ default:\r
+ return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;\r
+ }\r
+#endif\r
+}\r
+\r
+static int ecdh_make_public_internal( mbedtls_ecdh_context_mbed *ctx,\r
+ size_t *olen, int point_format,\r
+ unsigned char *buf, size_t blen,\r
+ int (*f_rng)(void *,\r
+ unsigned char *,\r
+ size_t),\r
+ void *p_rng,\r
+ int restart_enabled )\r
+{\r
+ int ret;\r
+#if defined(MBEDTLS_ECP_RESTARTABLE)\r
+ mbedtls_ecp_restart_ctx *rs_ctx = NULL;\r
+#endif\r
+\r
+ if( ctx->grp.pbits == 0 )\r
+ return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );\r
+\r
+#if defined(MBEDTLS_ECP_RESTARTABLE)\r
+ if( restart_enabled )\r
+ rs_ctx = &ctx->rs;\r
+#else\r
+ (void) restart_enabled;\r
+#endif\r
+\r
+#if defined(MBEDTLS_ECP_RESTARTABLE)\r
+ if( ( ret = ecdh_gen_public_restartable( &ctx->grp, &ctx->d, &ctx->Q,\r
+ f_rng, p_rng, rs_ctx ) ) != 0 )\r
+ return( ret );\r
+#else\r
+ if( ( ret = mbedtls_ecdh_gen_public( &ctx->grp, &ctx->d, &ctx->Q,\r
+ f_rng, p_rng ) ) != 0 )\r
+ return( ret );\r
+#endif /* MBEDTLS_ECP_RESTARTABLE */\r
+\r
+ return mbedtls_ecp_tls_write_point( &ctx->grp, &ctx->Q, point_format, olen,\r
+ buf, blen );\r
+}\r
+\r
+/*\r
+ * Setup and export the client public value\r
+ */\r
+int mbedtls_ecdh_make_public( mbedtls_ecdh_context *ctx, size_t *olen,\r
+ unsigned char *buf, size_t blen,\r
+ int (*f_rng)(void *, unsigned char *, size_t),\r
+ void *p_rng )\r
+{\r
+ int restart_enabled = 0;\r
+ ECDH_VALIDATE_RET( ctx != NULL );\r
+ ECDH_VALIDATE_RET( olen != NULL );\r
+ ECDH_VALIDATE_RET( buf != NULL );\r
+ ECDH_VALIDATE_RET( f_rng != NULL );\r
+\r
+#if defined(MBEDTLS_ECP_RESTARTABLE)\r
+ restart_enabled = ctx->restart_enabled;\r
+#endif\r
+\r
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)\r
+ return( ecdh_make_public_internal( ctx, olen, ctx->point_format, buf, blen,\r
+ f_rng, p_rng, restart_enabled ) );\r
+#else\r
+ switch( ctx->var )\r
+ {\r
+ case MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0:\r
+ return( ecdh_make_public_internal( &ctx->ctx.mbed_ecdh, olen,\r
+ ctx->point_format, buf, blen,\r
+ f_rng, p_rng,\r
+ restart_enabled ) );\r
+ default:\r
+ return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;\r
+ }\r
+#endif\r
+}\r
+\r
+static int ecdh_read_public_internal( mbedtls_ecdh_context_mbed *ctx,\r
+ const unsigned char *buf, size_t blen )\r
+{\r
+ int ret;\r
+ const unsigned char *p = buf;\r
+\r
+ if( ( ret = mbedtls_ecp_tls_read_point( &ctx->grp, &ctx->Qp, &p,\r
+ blen ) ) != 0 )\r
+ return( ret );\r
+\r
+ if( (size_t)( p - buf ) != blen )\r
+ return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );\r
+\r
+ return( 0 );\r
+}\r
+\r
+/*\r
+ * Parse and import the client's public value\r
+ */\r
+int mbedtls_ecdh_read_public( mbedtls_ecdh_context *ctx,\r
+ const unsigned char *buf, size_t blen )\r
+{\r
+ ECDH_VALIDATE_RET( ctx != NULL );\r
+ ECDH_VALIDATE_RET( buf != NULL );\r
+\r
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)\r
+ return( ecdh_read_public_internal( ctx, buf, blen ) );\r
+#else\r
+ switch( ctx->var )\r
+ {\r
+ case MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0:\r
+ return( ecdh_read_public_internal( &ctx->ctx.mbed_ecdh,\r
+ buf, blen ) );\r
+ default:\r
+ return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;\r
+ }\r
+#endif\r
+}\r
+\r
+static int ecdh_calc_secret_internal( mbedtls_ecdh_context_mbed *ctx,\r
+ size_t *olen, unsigned char *buf,\r
+ size_t blen,\r
+ int (*f_rng)(void *,\r
+ unsigned char *,\r
+ size_t),\r
+ void *p_rng,\r
+ int restart_enabled )\r
+{\r
+ int ret;\r
+#if defined(MBEDTLS_ECP_RESTARTABLE)\r
+ mbedtls_ecp_restart_ctx *rs_ctx = NULL;\r
+#endif\r
+\r
+ if( ctx == NULL || ctx->grp.pbits == 0 )\r
+ return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );\r
+\r
+#if defined(MBEDTLS_ECP_RESTARTABLE)\r
+ if( restart_enabled )\r
+ rs_ctx = &ctx->rs;\r
+#else\r
+ (void) restart_enabled;\r
+#endif\r
+\r
+#if defined(MBEDTLS_ECP_RESTARTABLE)\r
+ if( ( ret = ecdh_compute_shared_restartable( &ctx->grp, &ctx->z, &ctx->Qp,\r
+ &ctx->d, f_rng, p_rng,\r
+ rs_ctx ) ) != 0 )\r
+ {\r
+ return( ret );\r
+ }\r
+#else\r
+ if( ( ret = mbedtls_ecdh_compute_shared( &ctx->grp, &ctx->z, &ctx->Qp,\r
+ &ctx->d, f_rng, p_rng ) ) != 0 )\r
+ {\r
+ return( ret );\r
+ }\r
+#endif /* MBEDTLS_ECP_RESTARTABLE */\r
+\r
+ if( mbedtls_mpi_size( &ctx->z ) > blen )\r
+ return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );\r
+\r
+ *olen = ctx->grp.pbits / 8 + ( ( ctx->grp.pbits % 8 ) != 0 );\r
+\r
+ if( mbedtls_ecp_get_type( &ctx->grp ) == MBEDTLS_ECP_TYPE_MONTGOMERY )\r
+ return mbedtls_mpi_write_binary_le( &ctx->z, buf, *olen );\r
+\r
+ return mbedtls_mpi_write_binary( &ctx->z, buf, *olen );\r
+}\r
+\r
+/*\r
+ * Derive and export the shared secret\r
+ */\r
+int mbedtls_ecdh_calc_secret( mbedtls_ecdh_context *ctx, size_t *olen,\r
+ unsigned char *buf, size_t blen,\r
+ int (*f_rng)(void *, unsigned char *, size_t),\r
+ void *p_rng )\r
+{\r
+ int restart_enabled = 0;\r
+ ECDH_VALIDATE_RET( ctx != NULL );\r
+ ECDH_VALIDATE_RET( olen != NULL );\r
+ ECDH_VALIDATE_RET( buf != NULL );\r
+\r
+#if defined(MBEDTLS_ECP_RESTARTABLE)\r
+ restart_enabled = ctx->restart_enabled;\r
+#endif\r
+\r
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)\r
+ return( ecdh_calc_secret_internal( ctx, olen, buf, blen, f_rng, p_rng,\r
+ restart_enabled ) );\r
+#else\r
+ switch( ctx->var )\r
+ {\r
+ case MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0:\r
+ return( ecdh_calc_secret_internal( &ctx->ctx.mbed_ecdh, olen, buf,\r
+ blen, f_rng, p_rng,\r
+ restart_enabled ) );\r
+ default:\r
+ return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );\r
+ }\r
+#endif\r
+}\r
+\r
+#endif /* MBEDTLS_ECDH_C */\r
projects / freertos / blobdiff