139 lines
4.5 KiB
C
139 lines
4.5 KiB
C
/*
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* PSA ECP layer on top of Mbed TLS crypto
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*/
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/*
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* Copyright The Mbed TLS Contributors
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* SPDX-License-Identifier: Apache-2.0
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*
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* Licensed under the Apache License, Version 2.0 (the "License"); you may
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* not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "common.h"
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#if defined(MBEDTLS_PSA_CRYPTO_C)
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#include <psa/crypto.h>
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#include "psa_crypto_core.h"
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#include "psa_crypto_ecp.h"
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#include <stdlib.h>
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#include <string.h>
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#include "mbedtls/platform.h"
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#if !defined(MBEDTLS_PLATFORM_C)
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#define mbedtls_calloc calloc
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#define mbedtls_free free
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#endif
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#include <mbedtls/ecp.h>
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#include <mbedtls/error.h>
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#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || \
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defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) || \
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defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
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defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH) || \
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defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)
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psa_status_t mbedtls_psa_ecp_load_representation(
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psa_key_type_t type, const uint8_t *data, size_t data_length,
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mbedtls_ecp_keypair **p_ecp )
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{
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mbedtls_ecp_group_id grp_id = MBEDTLS_ECP_DP_NONE;
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psa_status_t status;
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mbedtls_ecp_keypair *ecp = NULL;
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size_t curve_size = data_length;
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if( PSA_KEY_TYPE_IS_PUBLIC_KEY( type ) &&
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PSA_KEY_TYPE_ECC_GET_FAMILY( type ) != PSA_ECC_FAMILY_MONTGOMERY )
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{
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/* A Weierstrass public key is represented as:
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* - The byte 0x04;
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* - `x_P` as a `ceiling(m/8)`-byte string, big-endian;
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* - `y_P` as a `ceiling(m/8)`-byte string, big-endian.
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* So its data length is 2m+1 where m is the curve size in bits.
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*/
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if( ( data_length & 1 ) == 0 )
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return( PSA_ERROR_INVALID_ARGUMENT );
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curve_size = data_length / 2;
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/* Montgomery public keys are represented in compressed format, meaning
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* their curve_size is equal to the amount of input. */
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/* Private keys are represented in uncompressed private random integer
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* format, meaning their curve_size is equal to the amount of input. */
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}
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/* Allocate and initialize a key representation. */
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ecp = mbedtls_calloc( 1, sizeof( mbedtls_ecp_keypair ) );
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if( ecp == NULL )
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return( PSA_ERROR_INSUFFICIENT_MEMORY );
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mbedtls_ecp_keypair_init( ecp );
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/* Load the group. */
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grp_id = mbedtls_ecc_group_of_psa( PSA_KEY_TYPE_ECC_GET_FAMILY( type ),
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curve_size );
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if( grp_id == MBEDTLS_ECP_DP_NONE )
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{
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status = PSA_ERROR_INVALID_ARGUMENT;
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goto exit;
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}
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status = mbedtls_to_psa_error(
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mbedtls_ecp_group_load( &ecp->grp, grp_id ) );
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if( status != PSA_SUCCESS )
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goto exit;
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/* Load the key material. */
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if( PSA_KEY_TYPE_IS_PUBLIC_KEY( type ) )
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{
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/* Load the public value. */
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status = mbedtls_to_psa_error(
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mbedtls_ecp_point_read_binary( &ecp->grp, &ecp->Q,
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data,
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data_length ) );
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if( status != PSA_SUCCESS )
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goto exit;
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/* Check that the point is on the curve. */
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status = mbedtls_to_psa_error(
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mbedtls_ecp_check_pubkey( &ecp->grp, &ecp->Q ) );
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if( status != PSA_SUCCESS )
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goto exit;
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}
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else
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{
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/* Load and validate the secret value. */
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status = mbedtls_to_psa_error(
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mbedtls_ecp_read_key( ecp->grp.id,
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ecp,
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data,
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data_length ) );
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if( status != PSA_SUCCESS )
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goto exit;
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}
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*p_ecp = ecp;
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exit:
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if( status != PSA_SUCCESS )
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{
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mbedtls_ecp_keypair_free( ecp );
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mbedtls_free( ecp );
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}
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return( status );
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}
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#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) ||
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* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) ||
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* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) ||
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* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH) ||
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* defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) */
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#endif /* MBEDTLS_PSA_CRYPTO_C */
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