| /* |
| * PSA RSA 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_random_impl.h" |
| #include "psa_crypto_rsa.h" |
| |
| #include <stdlib.h> |
| #include <string.h> |
| #include "mbedtls/platform.h" |
| #if !defined(MBEDTLS_PLATFORM_C) |
| #define mbedtls_calloc calloc |
| #define mbedtls_free free |
| #endif |
| |
| #include <mbedtls/rsa.h> |
| #include <mbedtls/error.h> |
| #include <mbedtls/pk.h> |
| #include <mbedtls/pk_internal.h> |
| |
| #if ( defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || \ |
| ( defined(PSA_CRYPTO_DRIVER_TEST) && \ |
| defined(MBEDTLS_PSA_ACCEL_KEY_TYPE_RSA_KEY_PAIR) ) ) |
| #define BUILTIN_KEY_TYPE_RSA_KEY_PAIR 1 |
| #endif |
| |
| #if ( defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) || \ |
| ( defined(PSA_CRYPTO_DRIVER_TEST) && \ |
| defined(MBEDTLS_PSA_ACCEL_KEY_TYPE_RSA_PUBLIC_KEY) ) ) |
| #define BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY 1 |
| #endif |
| |
| #if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT) || \ |
| defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) || \ |
| defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP) || \ |
| defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS) || \ |
| defined(BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || \ |
| defined(BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) |
| |
| /* Mbed TLS doesn't support non-byte-aligned key sizes (i.e. key sizes |
| * that are not a multiple of 8) well. For example, there is only |
| * mbedtls_rsa_get_len(), which returns a number of bytes, and no |
| * way to return the exact bit size of a key. |
| * To keep things simple, reject non-byte-aligned key sizes. */ |
| static psa_status_t psa_check_rsa_key_byte_aligned( |
| const mbedtls_rsa_context *rsa ) |
| { |
| mbedtls_mpi n; |
| psa_status_t status; |
| mbedtls_mpi_init( &n ); |
| status = mbedtls_to_psa_error( |
| mbedtls_rsa_export( rsa, &n, NULL, NULL, NULL, NULL ) ); |
| if( status == PSA_SUCCESS ) |
| { |
| if( mbedtls_mpi_bitlen( &n ) % 8 != 0 ) |
| status = PSA_ERROR_NOT_SUPPORTED; |
| } |
| mbedtls_mpi_free( &n ); |
| return( status ); |
| } |
| |
| psa_status_t mbedtls_psa_rsa_load_representation( |
| psa_key_type_t type, const uint8_t *data, size_t data_length, |
| mbedtls_rsa_context **p_rsa ) |
| { |
| psa_status_t status; |
| mbedtls_pk_context ctx; |
| size_t bits; |
| mbedtls_pk_init( &ctx ); |
| |
| /* Parse the data. */ |
| if( PSA_KEY_TYPE_IS_KEY_PAIR( type ) ) |
| status = mbedtls_to_psa_error( |
| mbedtls_pk_parse_key( &ctx, data, data_length, NULL, 0 ) ); |
| else |
| status = mbedtls_to_psa_error( |
| mbedtls_pk_parse_public_key( &ctx, data, data_length ) ); |
| if( status != PSA_SUCCESS ) |
| goto exit; |
| |
| /* We have something that the pkparse module recognizes. If it is a |
| * valid RSA key, store it. */ |
| if( mbedtls_pk_get_type( &ctx ) != MBEDTLS_PK_RSA ) |
| { |
| status = PSA_ERROR_INVALID_ARGUMENT; |
| goto exit; |
| } |
| |
| /* The size of an RSA key doesn't have to be a multiple of 8. Mbed TLS |
| * supports non-byte-aligned key sizes, but not well. For example, |
| * mbedtls_rsa_get_len() returns the key size in bytes, not in bits. */ |
| bits = PSA_BYTES_TO_BITS( mbedtls_rsa_get_len( mbedtls_pk_rsa( ctx ) ) ); |
| if( bits > PSA_VENDOR_RSA_MAX_KEY_BITS ) |
| { |
| status = PSA_ERROR_NOT_SUPPORTED; |
| goto exit; |
| } |
| status = psa_check_rsa_key_byte_aligned( mbedtls_pk_rsa( ctx ) ); |
| if( status != PSA_SUCCESS ) |
| goto exit; |
| |
| /* Copy out the pointer to the RSA context, and reset the PK context |
| * such that pk_free doesn't free the RSA context we just grabbed. */ |
| *p_rsa = mbedtls_pk_rsa( ctx ); |
| ctx.pk_info = NULL; |
| |
| exit: |
| mbedtls_pk_free( &ctx ); |
| return( status ); |
| } |
| #endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT) || |
| * defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) || |
| * defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP) || |
| * defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS) || |
| * defined(BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || |
| * defined(BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) */ |
| |
| #if defined(BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || \ |
| defined(BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) |
| |
| static psa_status_t rsa_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_rsa_context *rsa = NULL; |
| |
| /* Parse input */ |
| status = mbedtls_psa_rsa_load_representation( attributes->core.type, |
| data, |
| data_length, |
| &rsa ); |
| if( status != PSA_SUCCESS ) |
| goto exit; |
| |
| *bits = (psa_key_bits_t) PSA_BYTES_TO_BITS( mbedtls_rsa_get_len( rsa ) ); |
| |
| /* Re-export the data to PSA export format, such that we can store export |
| * representation in the key slot. Export representation in case of RSA is |
| * the smallest representation that's allowed as input, so a straight-up |
| * allocation of the same size as the input buffer will be large enough. */ |
| status = mbedtls_psa_rsa_export_key( attributes->core.type, |
| rsa, |
| key_buffer, |
| key_buffer_size, |
| key_buffer_length ); |
| exit: |
| /* Always free the RSA object */ |
| mbedtls_rsa_free( rsa ); |
| mbedtls_free( rsa ); |
| |
| return( status ); |
| } |
| |
| psa_status_t mbedtls_psa_rsa_export_key( psa_key_type_t type, |
| mbedtls_rsa_context *rsa, |
| uint8_t *data, |
| size_t data_size, |
| size_t *data_length ) |
| { |
| #if defined(MBEDTLS_PK_WRITE_C) |
| int ret; |
| mbedtls_pk_context pk; |
| uint8_t *pos = data + data_size; |
| |
| mbedtls_pk_init( &pk ); |
| pk.pk_info = &mbedtls_rsa_info; |
| pk.pk_ctx = rsa; |
| |
| /* PSA Crypto API defines the format of an RSA key as a DER-encoded |
| * representation of the non-encrypted PKCS#1 RSAPrivateKey for a |
| * private key and of the RFC3279 RSAPublicKey for a public key. */ |
| if( PSA_KEY_TYPE_IS_KEY_PAIR( type ) ) |
| ret = mbedtls_pk_write_key_der( &pk, data, data_size ); |
| else |
| ret = mbedtls_pk_write_pubkey( &pos, data, &pk ); |
| |
| if( ret < 0 ) |
| { |
| /* Clean up in case pk_write failed halfway through. */ |
| memset( data, 0, data_size ); |
| return( mbedtls_to_psa_error( ret ) ); |
| } |
| |
| /* The mbedtls_pk_xxx functions write to the end of the buffer. |
| * Move the data to the beginning and erase remaining data |
| * at the original location. */ |
| if( 2 * (size_t) ret <= data_size ) |
| { |
| memcpy( data, data + data_size - ret, ret ); |
| memset( data + data_size - ret, 0, ret ); |
| } |
| else if( (size_t) ret < data_size ) |
| { |
| memmove( data, data + data_size - ret, ret ); |
| memset( data + ret, 0, data_size - ret ); |
| } |
| |
| *data_length = ret; |
| return( PSA_SUCCESS ); |
| #else |
| (void) type; |
| (void) rsa; |
| (void) data; |
| (void) data_size; |
| (void) data_length; |
| return( PSA_ERROR_NOT_SUPPORTED ); |
| #endif /* MBEDTLS_PK_WRITE_C */ |
| } |
| |
| static psa_status_t rsa_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_rsa_context *rsa = NULL; |
| |
| status = mbedtls_psa_rsa_load_representation( |
| attributes->core.type, key_buffer, key_buffer_size, &rsa ); |
| if( status != PSA_SUCCESS ) |
| return( status ); |
| |
| status = mbedtls_psa_rsa_export_key( PSA_KEY_TYPE_RSA_PUBLIC_KEY, |
| rsa, |
| data, |
| data_size, |
| data_length ); |
| |
| mbedtls_rsa_free( rsa ); |
| mbedtls_free( rsa ); |
| |
| return( status ); |
| } |
| #endif /* defined(BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || |
| * defined(BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) */ |
| |
| #if defined(BUILTIN_KEY_TYPE_RSA_KEY_PAIR) |
| static psa_status_t psa_rsa_read_exponent( const uint8_t *domain_parameters, |
| size_t domain_parameters_size, |
| int *exponent ) |
| { |
| size_t i; |
| uint32_t acc = 0; |
| |
| if( domain_parameters_size == 0 ) |
| { |
| *exponent = 65537; |
| return( PSA_SUCCESS ); |
| } |
| |
| /* Mbed TLS encodes the public exponent as an int. For simplicity, only |
| * support values that fit in a 32-bit integer, which is larger than |
| * int on just about every platform anyway. */ |
| if( domain_parameters_size > sizeof( acc ) ) |
| return( PSA_ERROR_NOT_SUPPORTED ); |
| for( i = 0; i < domain_parameters_size; i++ ) |
| acc = ( acc << 8 ) | domain_parameters[i]; |
| if( acc > INT_MAX ) |
| return( PSA_ERROR_NOT_SUPPORTED ); |
| *exponent = acc; |
| return( PSA_SUCCESS ); |
| } |
| |
| static psa_status_t rsa_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; |
| mbedtls_rsa_context rsa; |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| int exponent; |
| |
| status = psa_rsa_read_exponent( attributes->domain_parameters, |
| attributes->domain_parameters_size, |
| &exponent ); |
| if( status != PSA_SUCCESS ) |
| return( status ); |
| |
| mbedtls_rsa_init( &rsa, MBEDTLS_RSA_PKCS_V15, MBEDTLS_MD_NONE ); |
| ret = mbedtls_rsa_gen_key( &rsa, |
| mbedtls_psa_get_random, |
| MBEDTLS_PSA_RANDOM_STATE, |
| (unsigned int)attributes->core.bits, |
| exponent ); |
| if( ret != 0 ) |
| return( mbedtls_to_psa_error( ret ) ); |
| |
| status = mbedtls_psa_rsa_export_key( attributes->core.type, |
| &rsa, key_buffer, key_buffer_size, |
| key_buffer_length ); |
| mbedtls_rsa_free( &rsa ); |
| |
| return( status ); |
| } |
| #endif /* defined(BUILTIN_KEY_TYPE_RSA_KEY_PAIR) */ |
| |
| #if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || \ |
| defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) |
| |
| psa_status_t mbedtls_psa_rsa_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 ) |
| { |
| return( rsa_import_key( attributes, data, data_length, |
| key_buffer, key_buffer_size, |
| key_buffer_length, bits ) ); |
| } |
| |
| psa_status_t mbedtls_psa_rsa_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 ) |
| { |
| return( rsa_export_public_key( attributes, key_buffer, key_buffer_size, |
| data, data_size, data_length ) ); |
| } |
| |
| #endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || |
| * defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) */ |
| |
| #if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) |
| psa_status_t mbedtls_psa_rsa_generate_key( |
| const psa_key_attributes_t *attributes, |
| uint8_t *key_buffer, size_t key_buffer_size, size_t *key_buffer_length ) |
| { |
| return( rsa_generate_key( attributes, key_buffer, key_buffer_size, |
| key_buffer_length ) ); |
| } |
| #endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) */ |
| |
| /* |
| * BEYOND THIS POINT, TEST DRIVER ENTRY POINTS ONLY. |
| */ |
| |
| #if defined(PSA_CRYPTO_DRIVER_TEST) |
| |
| #if defined(MBEDTLS_PSA_ACCEL_KEY_TYPE_RSA_KEY_PAIR) || \ |
| defined(MBEDTLS_PSA_ACCEL_KEY_TYPE_RSA_PUBLIC_KEY) |
| |
| psa_status_t mbedtls_transparent_test_driver_rsa_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 ) |
| { |
| return( rsa_import_key( attributes, data, data_length, |
| key_buffer, key_buffer_size, |
| key_buffer_length, bits ) ); |
| } |
| |
| psa_status_t mbedtls_transparent_test_driver_rsa_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 ) |
| { |
| return( rsa_export_public_key( attributes, key_buffer, key_buffer_size, |
| data, data_size, data_length ) ); |
| } |
| |
| #endif /* defined(MBEDTLS_PSA_ACCEL_KEY_TYPE_RSA_KEY_PAIR) || |
| defined(MBEDTLS_PSA_ACCEL_KEY_TYPE_RSA_PUBLIC_KEY) */ |
| |
| #if defined(MBEDTLS_PSA_ACCEL_KEY_TYPE_RSA_KEY_PAIR) |
| psa_status_t mbedtls_transparent_test_driver_rsa_generate_key( |
| const psa_key_attributes_t *attributes, |
| uint8_t *key_buffer, size_t key_buffer_size, size_t *key_buffer_length ) |
| { |
| return( rsa_generate_key( attributes, key_buffer, key_buffer_size, |
| key_buffer_length ) ); |
| } |
| #endif /* defined(MBEDTLS_PSA_ACCEL_KEY_TYPE_RSA_KEY_PAIR) */ |
| |
| #endif /* PSA_CRYPTO_DRIVER_TEST */ |
| |
| #endif /* MBEDTLS_PSA_CRYPTO_C */ |
