diff options
Diffstat (limited to 'library/psa_crypto_ecp.c')
| -rw-r--r-- | library/psa_crypto_ecp.c | 540 |
1 files changed, 540 insertions, 0 deletions
diff --git a/library/psa_crypto_ecp.c b/library/psa_crypto_ecp.c new file mode 100644 index 000000000..537a74840 --- /dev/null +++ b/library/psa_crypto_ecp.c @@ -0,0 +1,540 @@ +/* + * PSA ECP layer on top of Mbed TLS crypto + */ +/* + * 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. + */ + +#include "common.h" + +#if defined(MBEDTLS_PSA_CRYPTO_C) + +#include <psa/crypto.h> +#include "psa_crypto_core.h" +#include "psa_crypto_ecp.h" +#include "psa_crypto_random_impl.h" +#include "hash_info.h" + +#include <stdlib.h> +#include <string.h> +#include "mbedtls/platform.h" + +#include <mbedtls/ecdsa.h> +#include <mbedtls/ecdh.h> +#include <mbedtls/ecp.h> +#include <mbedtls/error.h> + +#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || \ + defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) || \ + defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \ + defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) || \ + defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH) +psa_status_t mbedtls_psa_ecp_load_representation( + psa_key_type_t type, size_t curve_bits, + const uint8_t *data, size_t data_length, + mbedtls_ecp_keypair **p_ecp ) +{ + mbedtls_ecp_group_id grp_id = MBEDTLS_ECP_DP_NONE; + psa_status_t status; + mbedtls_ecp_keypair *ecp = NULL; + size_t curve_bytes = data_length; + int explicit_bits = ( curve_bits != 0 ); + + if( PSA_KEY_TYPE_IS_PUBLIC_KEY( type ) && + PSA_KEY_TYPE_ECC_GET_FAMILY( type ) != PSA_ECC_FAMILY_MONTGOMERY ) + { + /* A Weierstrass public key is represented as: + * - The byte 0x04; + * - `x_P` as a `ceiling(m/8)`-byte string, big-endian; + * - `y_P` as a `ceiling(m/8)`-byte string, big-endian. + * So its data length is 2m+1 where m is the curve size in bits. + */ + if( ( data_length & 1 ) == 0 ) + return( PSA_ERROR_INVALID_ARGUMENT ); + curve_bytes = data_length / 2; + + /* Montgomery public keys are represented in compressed format, meaning + * their curve_bytes is equal to the amount of input. */ + + /* Private keys are represented in uncompressed private random integer + * format, meaning their curve_bytes is equal to the amount of input. */ + } + + if( explicit_bits ) + { + /* With an explicit bit-size, the data must have the matching length. */ + if( curve_bytes != PSA_BITS_TO_BYTES( curve_bits ) ) + return( PSA_ERROR_INVALID_ARGUMENT ); + } + else + { + /* We need to infer the bit-size from the data. Since the only + * information we have is the length in bytes, the value of curve_bits + * at this stage is rounded up to the nearest multiple of 8. */ + curve_bits = PSA_BYTES_TO_BITS( curve_bytes ); + } + + /* Allocate and initialize a key representation. */ + ecp = mbedtls_calloc( 1, sizeof( mbedtls_ecp_keypair ) ); + if( ecp == NULL ) + return( PSA_ERROR_INSUFFICIENT_MEMORY ); + mbedtls_ecp_keypair_init( ecp ); + + /* Load the group. */ + grp_id = mbedtls_ecc_group_of_psa( PSA_KEY_TYPE_ECC_GET_FAMILY( type ), + curve_bits, !explicit_bits ); + if( grp_id == MBEDTLS_ECP_DP_NONE ) + { + /* We can't distinguish between a nonsensical family/size combination + * (which would warrant PSA_ERROR_INVALID_ARGUMENT) and a + * well-regarded curve that Mbed TLS just doesn't know about (which + * would warrant PSA_ERROR_NOT_SUPPORTED). For uniformity with how + * curves that Mbed TLS knows about but for which support is disabled + * at build time, return NOT_SUPPORTED. */ + status = PSA_ERROR_NOT_SUPPORTED; + goto exit; + } + + status = mbedtls_to_psa_error( + mbedtls_ecp_group_load( &ecp->grp, grp_id ) ); + if( status != PSA_SUCCESS ) + goto exit; + + /* Load the key material. */ + if( PSA_KEY_TYPE_IS_PUBLIC_KEY( type ) ) + { + /* Load the public value. */ + status = mbedtls_to_psa_error( + mbedtls_ecp_point_read_binary( &ecp->grp, &ecp->Q, + data, + data_length ) ); + if( status != PSA_SUCCESS ) + goto exit; + + /* Check that the point is on the curve. */ + status = mbedtls_to_psa_error( + mbedtls_ecp_check_pubkey( &ecp->grp, &ecp->Q ) ); + if( status != PSA_SUCCESS ) + goto exit; + } + else + { + /* Load and validate the secret value. */ + status = mbedtls_to_psa_error( + mbedtls_ecp_read_key( ecp->grp.id, + ecp, + data, + data_length ) ); + if( status != PSA_SUCCESS ) + goto exit; + } + + *p_ecp = ecp; +exit: + if( status != PSA_SUCCESS ) + { + mbedtls_ecp_keypair_free( ecp ); + mbedtls_free( ecp ); + } + + return( status ); +} +#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || + * defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) || + * defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || + * defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) || + * defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH) */ + +#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || \ + defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) + +psa_status_t mbedtls_psa_ecp_import_key( + const psa_key_attributes_t *attributes, + const uint8_t *data, size_t data_length, + uint8_t *key_buffer, size_t key_buffer_size, + size_t *key_buffer_length, size_t *bits ) +{ + psa_status_t status; + mbedtls_ecp_keypair *ecp = NULL; + + /* Parse input */ + status = mbedtls_psa_ecp_load_representation( attributes->core.type, + attributes->core.bits, + data, + data_length, + &ecp ); + if( status != PSA_SUCCESS ) + goto exit; + + if( PSA_KEY_TYPE_ECC_GET_FAMILY( attributes->core.type ) == + PSA_ECC_FAMILY_MONTGOMERY ) + *bits = ecp->grp.nbits + 1; + else + *bits = ecp->grp.nbits; + + /* Re-export the data to PSA export format. There is currently no support + * for other input formats then the export format, so this is a 1-1 + * copy operation. */ + status = mbedtls_psa_ecp_export_key( attributes->core.type, + ecp, + key_buffer, + key_buffer_size, + key_buffer_length ); +exit: + /* Always free the PK object (will also free contained ECP context) */ + mbedtls_ecp_keypair_free( ecp ); + mbedtls_free( ecp ); + + return( status ); +} + +psa_status_t mbedtls_psa_ecp_export_key( psa_key_type_t type, + mbedtls_ecp_keypair *ecp, + uint8_t *data, + size_t data_size, + size_t *data_length ) +{ + psa_status_t status; + + if( PSA_KEY_TYPE_IS_PUBLIC_KEY( type ) ) + { + /* Check whether the public part is loaded */ + if( mbedtls_ecp_is_zero( &ecp->Q ) ) + { + /* Calculate the public key */ + status = mbedtls_to_psa_error( + mbedtls_ecp_mul( &ecp->grp, &ecp->Q, &ecp->d, &ecp->grp.G, + mbedtls_psa_get_random, + MBEDTLS_PSA_RANDOM_STATE ) ); + if( status != PSA_SUCCESS ) + return( status ); + } + + status = mbedtls_to_psa_error( + mbedtls_ecp_point_write_binary( &ecp->grp, &ecp->Q, + MBEDTLS_ECP_PF_UNCOMPRESSED, + data_length, + data, + data_size ) ); + if( status != PSA_SUCCESS ) + memset( data, 0, data_size ); + + return( status ); + } + else + { + if( data_size < PSA_BITS_TO_BYTES( ecp->grp.nbits ) ) + return( PSA_ERROR_BUFFER_TOO_SMALL ); + + status = mbedtls_to_psa_error( + mbedtls_ecp_write_key( ecp, + data, + PSA_BITS_TO_BYTES( ecp->grp.nbits ) ) ); + if( status == PSA_SUCCESS ) + *data_length = PSA_BITS_TO_BYTES( ecp->grp.nbits ); + else + memset( data, 0, data_size ); + + return( status ); + } +} + +psa_status_t mbedtls_psa_ecp_export_public_key( + const psa_key_attributes_t *attributes, + const uint8_t *key_buffer, size_t key_buffer_size, + uint8_t *data, size_t data_size, size_t *data_length ) +{ + psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; + mbedtls_ecp_keypair *ecp = NULL; + + status = mbedtls_psa_ecp_load_representation( + attributes->core.type, attributes->core.bits, + key_buffer, key_buffer_size, &ecp ); + if( status != PSA_SUCCESS ) + return( status ); + + status = mbedtls_psa_ecp_export_key( + PSA_KEY_TYPE_ECC_PUBLIC_KEY( + PSA_KEY_TYPE_ECC_GET_FAMILY( attributes->core.type ) ), + ecp, data, data_size, data_length ); + + mbedtls_ecp_keypair_free( ecp ); + mbedtls_free( ecp ); + + return( status ); +} +#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || + * defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) */ + +#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) +psa_status_t mbedtls_psa_ecp_generate_key( + const psa_key_attributes_t *attributes, + uint8_t *key_buffer, size_t key_buffer_size, size_t *key_buffer_length ) +{ + psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + + psa_ecc_family_t curve = PSA_KEY_TYPE_ECC_GET_FAMILY( + attributes->core.type ); + mbedtls_ecp_group_id grp_id = + mbedtls_ecc_group_of_psa( curve, attributes->core.bits, 0 ); + + const mbedtls_ecp_curve_info *curve_info = + mbedtls_ecp_curve_info_from_grp_id( grp_id ); + mbedtls_ecp_keypair ecp; + + if( attributes->domain_parameters_size != 0 ) + return( PSA_ERROR_NOT_SUPPORTED ); + + if( grp_id == MBEDTLS_ECP_DP_NONE || curve_info == NULL ) + return( PSA_ERROR_NOT_SUPPORTED ); + + mbedtls_ecp_keypair_init( &ecp ); + ret = mbedtls_ecp_gen_key( grp_id, &ecp, + mbedtls_psa_get_random, + MBEDTLS_PSA_RANDOM_STATE ); + if( ret != 0 ) + { + mbedtls_ecp_keypair_free( &ecp ); + return( mbedtls_to_psa_error( ret ) ); + } + + status = mbedtls_to_psa_error( + mbedtls_ecp_write_key( &ecp, key_buffer, key_buffer_size ) ); + + mbedtls_ecp_keypair_free( &ecp ); + + if( status == PSA_SUCCESS ) + *key_buffer_length = key_buffer_size; + + return( status ); +} +#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) */ + +/****************************************************************/ +/* ECDSA sign/verify */ +/****************************************************************/ + +#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \ + defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) +psa_status_t mbedtls_psa_ecdsa_sign_hash( + const psa_key_attributes_t *attributes, + const uint8_t *key_buffer, size_t key_buffer_size, + psa_algorithm_t alg, const uint8_t *hash, size_t hash_length, + uint8_t *signature, size_t signature_size, size_t *signature_length ) +{ + psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; + mbedtls_ecp_keypair *ecp = NULL; + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + size_t curve_bytes; + mbedtls_mpi r, s; + + status = mbedtls_psa_ecp_load_representation( attributes->core.type, + attributes->core.bits, + key_buffer, + key_buffer_size, + &ecp ); + if( status != PSA_SUCCESS ) + return( status ); + + curve_bytes = PSA_BITS_TO_BYTES( ecp->grp.pbits ); + mbedtls_mpi_init( &r ); + mbedtls_mpi_init( &s ); + + if( signature_size < 2 * curve_bytes ) + { + ret = MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL; + goto cleanup; + } + + if( PSA_ALG_ECDSA_IS_DETERMINISTIC( alg ) ) + { +#if defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) + psa_algorithm_t hash_alg = PSA_ALG_SIGN_GET_HASH( alg ); + mbedtls_md_type_t md_alg = mbedtls_hash_info_md_from_psa( hash_alg ); + MBEDTLS_MPI_CHK( mbedtls_ecdsa_sign_det_ext( + &ecp->grp, &r, &s, + &ecp->d, hash, + hash_length, md_alg, + mbedtls_psa_get_random, + MBEDTLS_PSA_RANDOM_STATE ) ); +#else + ret = MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE; + goto cleanup; +#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) */ + } + else + { + (void) alg; + MBEDTLS_MPI_CHK( mbedtls_ecdsa_sign( &ecp->grp, &r, &s, &ecp->d, + hash, hash_length, + mbedtls_psa_get_random, + MBEDTLS_PSA_RANDOM_STATE ) ); + } + + MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &r, + signature, + curve_bytes ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &s, + signature + curve_bytes, + curve_bytes ) ); +cleanup: + mbedtls_mpi_free( &r ); + mbedtls_mpi_free( &s ); + if( ret == 0 ) + *signature_length = 2 * curve_bytes; + + mbedtls_ecp_keypair_free( ecp ); + mbedtls_free( ecp ); + + return( mbedtls_to_psa_error( ret ) ); +} + +psa_status_t mbedtls_psa_ecdsa_verify_hash( + const psa_key_attributes_t *attributes, + const uint8_t *key_buffer, size_t key_buffer_size, + psa_algorithm_t alg, const uint8_t *hash, size_t hash_length, + const uint8_t *signature, size_t signature_length ) +{ + psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; + mbedtls_ecp_keypair *ecp = NULL; + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + size_t curve_bytes; + mbedtls_mpi r, s; + + (void)alg; + + status = mbedtls_psa_ecp_load_representation( attributes->core.type, + attributes->core.bits, + key_buffer, + key_buffer_size, + &ecp ); + if( status != PSA_SUCCESS ) + return( status ); + + curve_bytes = PSA_BITS_TO_BYTES( ecp->grp.pbits ); + mbedtls_mpi_init( &r ); + mbedtls_mpi_init( &s ); + + if( signature_length != 2 * curve_bytes ) + { + ret = MBEDTLS_ERR_ECP_VERIFY_FAILED; + goto cleanup; + } + + MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &r, + signature, + curve_bytes ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &s, + signature + curve_bytes, + curve_bytes ) ); + + /* Check whether the public part is loaded. If not, load it. */ + if( mbedtls_ecp_is_zero( &ecp->Q ) ) + { + MBEDTLS_MPI_CHK( + mbedtls_ecp_mul( &ecp->grp, &ecp->Q, &ecp->d, &ecp->grp.G, + mbedtls_psa_get_random, MBEDTLS_PSA_RANDOM_STATE ) ); + } + + ret = mbedtls_ecdsa_verify( &ecp->grp, hash, hash_length, + &ecp->Q, &r, &s ); + +cleanup: + mbedtls_mpi_free( &r ); + mbedtls_mpi_free( &s ); + mbedtls_ecp_keypair_free( ecp ); + mbedtls_free( ecp ); + + return( mbedtls_to_psa_error( ret ) ); +} + +#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \ + * defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) */ + +/****************************************************************/ +/* ECDH Key Agreement */ +/****************************************************************/ + +#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH) +psa_status_t mbedtls_psa_key_agreement_ecdh( + const psa_key_attributes_t *attributes, + const uint8_t *key_buffer, size_t key_buffer_size, + psa_algorithm_t alg, const uint8_t *peer_key, size_t peer_key_length, + uint8_t *shared_secret, size_t shared_secret_size, + size_t *shared_secret_length ) +{ + psa_status_t status; + if( ! PSA_KEY_TYPE_IS_ECC_KEY_PAIR( attributes->core.type ) || + ! PSA_ALG_IS_ECDH(alg) ) + return( PSA_ERROR_INVALID_ARGUMENT ); + mbedtls_ecp_keypair *ecp = NULL; + status = mbedtls_psa_ecp_load_representation( + attributes->core.type, + attributes->core.bits, + key_buffer, + key_buffer_size, + &ecp ); + if( status != PSA_SUCCESS ) + return( status ); + mbedtls_ecp_keypair *their_key = NULL; + mbedtls_ecdh_context ecdh; + size_t bits = 0; + psa_ecc_family_t curve = mbedtls_ecc_group_to_psa( ecp->grp.id, &bits ); + mbedtls_ecdh_init( &ecdh ); + + status = mbedtls_psa_ecp_load_representation( + PSA_KEY_TYPE_ECC_PUBLIC_KEY(curve), + bits, + peer_key, + peer_key_length, + &their_key ); + if( status != PSA_SUCCESS ) + goto exit; + + status = mbedtls_to_psa_error( + mbedtls_ecdh_get_params( &ecdh, their_key, MBEDTLS_ECDH_THEIRS ) ); + if( status != PSA_SUCCESS ) + goto exit; + status = mbedtls_to_psa_error( + mbedtls_ecdh_get_params( &ecdh, ecp, MBEDTLS_ECDH_OURS ) ); + if( status != PSA_SUCCESS ) + goto exit; + + status = mbedtls_to_psa_error( + mbedtls_ecdh_calc_secret( &ecdh, + shared_secret_length, + shared_secret, shared_secret_size, + mbedtls_psa_get_random, + MBEDTLS_PSA_RANDOM_STATE ) ); + if( status != PSA_SUCCESS ) + goto exit; + if( PSA_BITS_TO_BYTES( bits ) != *shared_secret_length ) + status = PSA_ERROR_CORRUPTION_DETECTED; +exit: + if( status != PSA_SUCCESS ) + mbedtls_platform_zeroize( shared_secret, shared_secret_size ); + mbedtls_ecdh_free( &ecdh ); + mbedtls_ecp_keypair_free( their_key ); + mbedtls_free( their_key ); + mbedtls_ecp_keypair_free( ecp ); + mbedtls_free( ecp ); + return( status ); +} +#endif /* MBEDTLS_PSA_BUILTIN_ALG_ECDH */ + + +#endif /* MBEDTLS_PSA_CRYPTO_C */ |