mbedtls/library/psa_crypto_rsa.c
Ronald Cron 0266cfed51 psa: Remove test code in the library
The current testing of the PSA configuration is
based on test code located in the library itself.

Remove this code as we are moving to using a
test library instead.

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
2021-12-06 07:50:27 +01:00

536 lines
18 KiB
C

/*
* 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 "psa_crypto_hash.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 "pk_wrap.h"
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || \
defined(MBEDTLS_PSA_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,
mbedtls_psa_get_random, MBEDTLS_PSA_RANDOM_STATE ) );
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_OAEP) ||
* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) ||
* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS) ||
* 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) || \
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 )
{
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 */
}
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 )
{
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(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) && \
defined(MBEDTLS_GENPRIME)
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 );
}
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 )
{
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 );
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(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR)
* defined(MBEDTLS_GENPRIME) */
/****************************************************************/
/* Sign/verify hashes */
/****************************************************************/
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS)
/* Decode the hash algorithm from alg and store the mbedtls encoding in
* md_alg. Verify that the hash length is acceptable. */
static psa_status_t psa_rsa_decode_md_type( psa_algorithm_t alg,
size_t hash_length,
mbedtls_md_type_t *md_alg )
{
psa_algorithm_t hash_alg = PSA_ALG_SIGN_GET_HASH( alg );
const mbedtls_md_info_t *md_info = mbedtls_md_info_from_psa( hash_alg );
*md_alg = mbedtls_md_get_type( md_info );
/* The Mbed TLS RSA module uses an unsigned int for hash length
* parameters. Validate that it fits so that we don't risk an
* overflow later. */
#if SIZE_MAX > UINT_MAX
if( hash_length > UINT_MAX )
return( PSA_ERROR_INVALID_ARGUMENT );
#endif
/* For signatures using a hash, the hash length must be correct. */
if( alg != PSA_ALG_RSA_PKCS1V15_SIGN_RAW )
{
if( md_info == NULL )
return( PSA_ERROR_NOT_SUPPORTED );
if( mbedtls_md_get_size( md_info ) != hash_length )
return( PSA_ERROR_INVALID_ARGUMENT );
}
return( PSA_SUCCESS );
}
psa_status_t mbedtls_psa_rsa_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_rsa_context *rsa = NULL;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_md_type_t md_alg;
status = mbedtls_psa_rsa_load_representation( attributes->core.type,
key_buffer,
key_buffer_size,
&rsa );
if( status != PSA_SUCCESS )
return( status );
status = psa_rsa_decode_md_type( alg, hash_length, &md_alg );
if( status != PSA_SUCCESS )
goto exit;
if( signature_size < mbedtls_rsa_get_len( rsa ) )
{
status = PSA_ERROR_BUFFER_TOO_SMALL;
goto exit;
}
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN)
if( PSA_ALG_IS_RSA_PKCS1V15_SIGN( alg ) )
{
ret = mbedtls_rsa_set_padding( rsa, MBEDTLS_RSA_PKCS_V15,
MBEDTLS_MD_NONE );
if( ret == 0 )
{
ret = mbedtls_rsa_pkcs1_sign( rsa,
mbedtls_psa_get_random,
MBEDTLS_PSA_RANDOM_STATE,
md_alg,
(unsigned int) hash_length,
hash,
signature );
}
}
else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS)
if( PSA_ALG_IS_RSA_PSS( alg ) )
{
ret = mbedtls_rsa_set_padding( rsa, MBEDTLS_RSA_PKCS_V21, md_alg );
if( ret == 0 )
{
ret = mbedtls_rsa_rsassa_pss_sign( rsa,
mbedtls_psa_get_random,
MBEDTLS_PSA_RANDOM_STATE,
MBEDTLS_MD_NONE,
(unsigned int) hash_length,
hash,
signature );
}
}
else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS */
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
if( ret == 0 )
*signature_length = mbedtls_rsa_get_len( rsa );
status = mbedtls_to_psa_error( ret );
exit:
mbedtls_rsa_free( rsa );
mbedtls_free( rsa );
return( status );
}
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS)
static int rsa_pss_expected_salt_len( psa_algorithm_t alg,
const mbedtls_rsa_context *rsa,
size_t hash_length )
{
if( PSA_ALG_IS_RSA_PSS_ANY_SALT( alg ) )
return( MBEDTLS_RSA_SALT_LEN_ANY );
/* Otherwise: standard salt length, i.e. largest possible salt length
* up to the hash length. */
int klen = (int) mbedtls_rsa_get_len( rsa ); // known to fit
int hlen = (int) hash_length; // known to fit
int room = klen - 2 - hlen;
if( room < 0 )
return( 0 ); // there is no valid signature in this case anyway
else if( room > hlen )
return( hlen );
else
return( room );
}
#endif /* MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS */
psa_status_t mbedtls_psa_rsa_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_rsa_context *rsa = NULL;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_md_type_t md_alg;
status = mbedtls_psa_rsa_load_representation( attributes->core.type,
key_buffer,
key_buffer_size,
&rsa );
if( status != PSA_SUCCESS )
goto exit;
status = psa_rsa_decode_md_type( alg, hash_length, &md_alg );
if( status != PSA_SUCCESS )
goto exit;
if( signature_length != mbedtls_rsa_get_len( rsa ) )
{
status = PSA_ERROR_INVALID_SIGNATURE;
goto exit;
}
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN)
if( PSA_ALG_IS_RSA_PKCS1V15_SIGN( alg ) )
{
ret = mbedtls_rsa_set_padding( rsa, MBEDTLS_RSA_PKCS_V15,
MBEDTLS_MD_NONE );
if( ret == 0 )
{
ret = mbedtls_rsa_pkcs1_verify( rsa,
md_alg,
(unsigned int) hash_length,
hash,
signature );
}
}
else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS)
if( PSA_ALG_IS_RSA_PSS( alg ) )
{
ret = mbedtls_rsa_set_padding( rsa, MBEDTLS_RSA_PKCS_V21, md_alg );
if( ret == 0 )
{
int slen = rsa_pss_expected_salt_len( alg, rsa, hash_length );
ret = mbedtls_rsa_rsassa_pss_verify_ext( rsa,
md_alg,
(unsigned) hash_length,
hash,
md_alg,
slen,
signature );
}
}
else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS */
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
/* Mbed TLS distinguishes "invalid padding" from "valid padding but
* the rest of the signature is invalid". This has little use in
* practice and PSA doesn't report this distinction. */
status = ( ret == MBEDTLS_ERR_RSA_INVALID_PADDING ) ?
PSA_ERROR_INVALID_SIGNATURE :
mbedtls_to_psa_error( ret );
exit:
mbedtls_rsa_free( rsa );
mbedtls_free( rsa );
return( status );
}
#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) ||
* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS) */
#endif /* MBEDTLS_PSA_CRYPTO_C */