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