mbedtls/library/psa_crypto.c
Gilles Peskine f76aa7789b Private EC key format: change to raw secret value (doc, import)
Change the import/export format of private elliptic curve keys from
RFC 5915 to the raw secret value. This commit updates the format
specification and the import code, but not the export code.
2018-10-31 14:10:06 +01:00

3651 lines
119 KiB
C

/*
* PSA crypto layer on top of Mbed TLS crypto
*/
/* Copyright (C) 2018, ARM Limited, All Rights Reserved
* 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.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*/
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#if defined(MBEDTLS_PSA_CRYPTO_C)
/*
* In case MBEDTLS_PSA_CRYPTO_SPM is defined the code is built for SPM (Secure
* Partition Manager) integration which separate the code into two parts
* NSPE (Non-Secure Process Environment) and SPE (Secure Process Environment).
* In this mode an additional header file should be included.
*/
#if defined(MBEDTLS_PSA_CRYPTO_SPM)
/*
* PSA_CRYPTO_SECURE means that this file is compiled to the SPE side.
* some headers will be affected by this flag.
*/
#define PSA_CRYPTO_SECURE 1
#include "crypto_spe.h"
#endif
#include "psa/crypto.h"
#include <stdlib.h>
#include <string.h>
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#define mbedtls_calloc calloc
#define mbedtls_free free
#endif
#include "mbedtls/arc4.h"
#include "mbedtls/asn1.h"
#include "mbedtls/bignum.h"
#include "mbedtls/blowfish.h"
#include "mbedtls/camellia.h"
#include "mbedtls/cipher.h"
#include "mbedtls/ccm.h"
#include "mbedtls/cmac.h"
#include "mbedtls/ctr_drbg.h"
#include "mbedtls/des.h"
#include "mbedtls/ecp.h"
#include "mbedtls/entropy.h"
#include "mbedtls/error.h"
#include "mbedtls/gcm.h"
#include "mbedtls/md2.h"
#include "mbedtls/md4.h"
#include "mbedtls/md5.h"
#include "mbedtls/md.h"
#include "mbedtls/md_internal.h"
#include "mbedtls/pk.h"
#include "mbedtls/pk_internal.h"
#include "mbedtls/ripemd160.h"
#include "mbedtls/rsa.h"
#include "mbedtls/sha1.h"
#include "mbedtls/sha256.h"
#include "mbedtls/sha512.h"
#include "mbedtls/xtea.h"
#define ARRAY_LENGTH( array ) ( sizeof( array ) / sizeof( *( array ) ) )
/* Implementation that should never be optimized out by the compiler */
static void mbedtls_zeroize( void *v, size_t n )
{
volatile unsigned char *p = v; while( n-- ) *p++ = 0;
}
/* constant-time buffer comparison */
static inline int safer_memcmp( const uint8_t *a, const uint8_t *b, size_t n )
{
size_t i;
unsigned char diff = 0;
for( i = 0; i < n; i++ )
diff |= a[i] ^ b[i];
return( diff );
}
/****************************************************************/
/* Global data, support functions and library management */
/****************************************************************/
/* Number of key slots (plus one because 0 is not used).
* The value is a compile-time constant for now, for simplicity. */
#define PSA_KEY_SLOT_COUNT 32
typedef struct
{
psa_key_type_t type;
psa_key_policy_t policy;
psa_key_lifetime_t lifetime;
union
{
struct raw_data
{
uint8_t *data;
size_t bytes;
} raw;
#if defined(MBEDTLS_RSA_C)
mbedtls_rsa_context *rsa;
#endif /* MBEDTLS_RSA_C */
#if defined(MBEDTLS_ECP_C)
mbedtls_ecp_keypair *ecp;
#endif /* MBEDTLS_ECP_C */
} data;
} key_slot_t;
static int key_type_is_raw_bytes( psa_key_type_t type )
{
return( PSA_KEY_TYPE_IS_UNSTRUCTURED( type ) );
}
typedef struct
{
int initialized;
mbedtls_entropy_context entropy;
mbedtls_ctr_drbg_context ctr_drbg;
key_slot_t key_slots[PSA_KEY_SLOT_COUNT];
} psa_global_data_t;
static psa_global_data_t global_data;
#define GUARD_MODULE_INITIALIZED \
if( global_data.initialized == 0 ) \
return( PSA_ERROR_BAD_STATE );
static psa_status_t mbedtls_to_psa_error( int ret )
{
/* If there's both a high-level code and low-level code, dispatch on
* the high-level code. */
switch( ret < -0x7f ? - ( -ret & 0x7f80 ) : ret )
{
case 0:
return( PSA_SUCCESS );
case MBEDTLS_ERR_AES_INVALID_KEY_LENGTH:
case MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH:
case MBEDTLS_ERR_AES_FEATURE_UNAVAILABLE:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_AES_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_ARC4_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_ASN1_OUT_OF_DATA:
case MBEDTLS_ERR_ASN1_UNEXPECTED_TAG:
case MBEDTLS_ERR_ASN1_INVALID_LENGTH:
case MBEDTLS_ERR_ASN1_LENGTH_MISMATCH:
case MBEDTLS_ERR_ASN1_INVALID_DATA:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_ASN1_ALLOC_FAILED:
return( PSA_ERROR_INSUFFICIENT_MEMORY );
case MBEDTLS_ERR_ASN1_BUF_TOO_SMALL:
return( PSA_ERROR_BUFFER_TOO_SMALL );
case MBEDTLS_ERR_BLOWFISH_INVALID_KEY_LENGTH:
case MBEDTLS_ERR_BLOWFISH_INVALID_INPUT_LENGTH:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_BLOWFISH_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_CAMELLIA_INVALID_KEY_LENGTH:
case MBEDTLS_ERR_CAMELLIA_INVALID_INPUT_LENGTH:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_CAMELLIA_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_CCM_BAD_INPUT:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_CCM_AUTH_FAILED:
return( PSA_ERROR_INVALID_SIGNATURE );
case MBEDTLS_ERR_CCM_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_CIPHER_ALLOC_FAILED:
return( PSA_ERROR_INSUFFICIENT_MEMORY );
case MBEDTLS_ERR_CIPHER_INVALID_PADDING:
return( PSA_ERROR_INVALID_PADDING );
case MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED:
return( PSA_ERROR_BAD_STATE );
case MBEDTLS_ERR_CIPHER_AUTH_FAILED:
return( PSA_ERROR_INVALID_SIGNATURE );
case MBEDTLS_ERR_CIPHER_INVALID_CONTEXT:
return( PSA_ERROR_TAMPERING_DETECTED );
case MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_CMAC_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED:
return( PSA_ERROR_INSUFFICIENT_ENTROPY );
case MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG:
case MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR:
return( PSA_ERROR_INSUFFICIENT_ENTROPY );
case MBEDTLS_ERR_DES_INVALID_INPUT_LENGTH:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_DES_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_ENTROPY_NO_SOURCES_DEFINED:
case MBEDTLS_ERR_ENTROPY_NO_STRONG_SOURCE:
case MBEDTLS_ERR_ENTROPY_SOURCE_FAILED:
return( PSA_ERROR_INSUFFICIENT_ENTROPY );
case MBEDTLS_ERR_GCM_AUTH_FAILED:
return( PSA_ERROR_INVALID_SIGNATURE );
case MBEDTLS_ERR_GCM_BAD_INPUT:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_GCM_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_MD2_HW_ACCEL_FAILED:
case MBEDTLS_ERR_MD4_HW_ACCEL_FAILED:
case MBEDTLS_ERR_MD5_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_MD_FEATURE_UNAVAILABLE:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_MD_BAD_INPUT_DATA:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_MD_ALLOC_FAILED:
return( PSA_ERROR_INSUFFICIENT_MEMORY );
case MBEDTLS_ERR_MD_FILE_IO_ERROR:
return( PSA_ERROR_STORAGE_FAILURE );
case MBEDTLS_ERR_MD_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_MPI_FILE_IO_ERROR:
return( PSA_ERROR_STORAGE_FAILURE );
case MBEDTLS_ERR_MPI_BAD_INPUT_DATA:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_MPI_INVALID_CHARACTER:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL:
return( PSA_ERROR_BUFFER_TOO_SMALL );
case MBEDTLS_ERR_MPI_NEGATIVE_VALUE:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_MPI_DIVISION_BY_ZERO:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_MPI_NOT_ACCEPTABLE:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_MPI_ALLOC_FAILED:
return( PSA_ERROR_INSUFFICIENT_MEMORY );
case MBEDTLS_ERR_PK_ALLOC_FAILED:
return( PSA_ERROR_INSUFFICIENT_MEMORY );
case MBEDTLS_ERR_PK_TYPE_MISMATCH:
case MBEDTLS_ERR_PK_BAD_INPUT_DATA:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_PK_FILE_IO_ERROR:
return( PSA_ERROR_STORAGE_FAILURE );
case MBEDTLS_ERR_PK_KEY_INVALID_VERSION:
case MBEDTLS_ERR_PK_KEY_INVALID_FORMAT:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_PK_UNKNOWN_PK_ALG:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_PK_PASSWORD_REQUIRED:
case MBEDTLS_ERR_PK_PASSWORD_MISMATCH:
return( PSA_ERROR_NOT_PERMITTED );
case MBEDTLS_ERR_PK_INVALID_PUBKEY:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_PK_INVALID_ALG:
case MBEDTLS_ERR_PK_UNKNOWN_NAMED_CURVE:
case MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_PK_SIG_LEN_MISMATCH:
return( PSA_ERROR_INVALID_SIGNATURE );
case MBEDTLS_ERR_PK_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_RIPEMD160_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_RSA_BAD_INPUT_DATA:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_RSA_INVALID_PADDING:
return( PSA_ERROR_INVALID_PADDING );
case MBEDTLS_ERR_RSA_KEY_GEN_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_RSA_KEY_CHECK_FAILED:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_RSA_PUBLIC_FAILED:
case MBEDTLS_ERR_RSA_PRIVATE_FAILED:
return( PSA_ERROR_TAMPERING_DETECTED );
case MBEDTLS_ERR_RSA_VERIFY_FAILED:
return( PSA_ERROR_INVALID_SIGNATURE );
case MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE:
return( PSA_ERROR_BUFFER_TOO_SMALL );
case MBEDTLS_ERR_RSA_RNG_FAILED:
return( PSA_ERROR_INSUFFICIENT_MEMORY );
case MBEDTLS_ERR_RSA_UNSUPPORTED_OPERATION:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_RSA_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_SHA1_HW_ACCEL_FAILED:
case MBEDTLS_ERR_SHA256_HW_ACCEL_FAILED:
case MBEDTLS_ERR_SHA512_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_XTEA_INVALID_INPUT_LENGTH:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_XTEA_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_ECP_BAD_INPUT_DATA:
case MBEDTLS_ERR_ECP_INVALID_KEY:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL:
return( PSA_ERROR_BUFFER_TOO_SMALL );
case MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH:
case MBEDTLS_ERR_ECP_VERIFY_FAILED:
return( PSA_ERROR_INVALID_SIGNATURE );
case MBEDTLS_ERR_ECP_ALLOC_FAILED:
return( PSA_ERROR_INSUFFICIENT_MEMORY );
case MBEDTLS_ERR_ECP_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
default:
return( PSA_ERROR_UNKNOWN_ERROR );
}
}
/* Retrieve a key slot, occupied or not. */
static psa_status_t psa_get_key_slot( psa_key_slot_t key,
key_slot_t **p_slot )
{
GUARD_MODULE_INITIALIZED;
/* 0 is not a valid slot number under any circumstance. This
* implementation provides slots number 1 to N where N is the
* number of available slots. */
if( key == 0 || key > ARRAY_LENGTH( global_data.key_slots ) )
return( PSA_ERROR_INVALID_ARGUMENT );
*p_slot = &global_data.key_slots[key - 1];
return( PSA_SUCCESS );
}
/* Retrieve an empty key slot (slot with no key data, but possibly
* with some metadata such as a policy). */
static psa_status_t psa_get_empty_key_slot( psa_key_slot_t key,
key_slot_t **p_slot )
{
psa_status_t status;
key_slot_t *slot = NULL;
*p_slot = NULL;
status = psa_get_key_slot( key, &slot );
if( status != PSA_SUCCESS )
return( status );
if( slot->type != PSA_KEY_TYPE_NONE )
return( PSA_ERROR_OCCUPIED_SLOT );
*p_slot = slot;
return( status );
}
/** Retrieve a slot which must contain a key. The key must have allow all the
* usage flags set in \p usage. If \p alg is nonzero, the key must allow
* operations with this algorithm. */
static psa_status_t psa_get_key_from_slot( psa_key_slot_t key,
key_slot_t **p_slot,
psa_key_usage_t usage,
psa_algorithm_t alg )
{
psa_status_t status;
key_slot_t *slot = NULL;
*p_slot = NULL;
status = psa_get_key_slot( key, &slot );
if( status != PSA_SUCCESS )
return( status );
if( slot->type == PSA_KEY_TYPE_NONE )
return( PSA_ERROR_EMPTY_SLOT );
/* Enforce that usage policy for the key slot contains all the flags
* required by the usage parameter. There is one exception: public
* keys can always be exported, so we treat public key objects as
* if they had the export flag. */
if( PSA_KEY_TYPE_IS_PUBLIC_KEY( slot->type ) )
usage &= ~PSA_KEY_USAGE_EXPORT;
if( ( slot->policy.usage & usage ) != usage )
return( PSA_ERROR_NOT_PERMITTED );
if( alg != 0 && ( alg != slot->policy.alg ) )
return( PSA_ERROR_NOT_PERMITTED );
*p_slot = slot;
return( PSA_SUCCESS );
}
/****************************************************************/
/* Key management */
/****************************************************************/
#if defined(MBEDTLS_ECP_C)
static psa_ecc_curve_t mbedtls_ecc_group_to_psa( mbedtls_ecp_group_id grpid )
{
switch( grpid )
{
case MBEDTLS_ECP_DP_SECP192R1:
return( PSA_ECC_CURVE_SECP192R1 );
case MBEDTLS_ECP_DP_SECP224R1:
return( PSA_ECC_CURVE_SECP224R1 );
case MBEDTLS_ECP_DP_SECP256R1:
return( PSA_ECC_CURVE_SECP256R1 );
case MBEDTLS_ECP_DP_SECP384R1:
return( PSA_ECC_CURVE_SECP384R1 );
case MBEDTLS_ECP_DP_SECP521R1:
return( PSA_ECC_CURVE_SECP521R1 );
case MBEDTLS_ECP_DP_BP256R1:
return( PSA_ECC_CURVE_BRAINPOOL_P256R1 );
case MBEDTLS_ECP_DP_BP384R1:
return( PSA_ECC_CURVE_BRAINPOOL_P384R1 );
case MBEDTLS_ECP_DP_BP512R1:
return( PSA_ECC_CURVE_BRAINPOOL_P512R1 );
case MBEDTLS_ECP_DP_CURVE25519:
return( PSA_ECC_CURVE_CURVE25519 );
case MBEDTLS_ECP_DP_SECP192K1:
return( PSA_ECC_CURVE_SECP192K1 );
case MBEDTLS_ECP_DP_SECP224K1:
return( PSA_ECC_CURVE_SECP224K1 );
case MBEDTLS_ECP_DP_SECP256K1:
return( PSA_ECC_CURVE_SECP256K1 );
case MBEDTLS_ECP_DP_CURVE448:
return( PSA_ECC_CURVE_CURVE448 );
default:
return( 0 );
}
}
static mbedtls_ecp_group_id mbedtls_ecc_group_of_psa( psa_ecc_curve_t curve )
{
switch( curve )
{
case PSA_ECC_CURVE_SECP192R1:
return( MBEDTLS_ECP_DP_SECP192R1 );
case PSA_ECC_CURVE_SECP224R1:
return( MBEDTLS_ECP_DP_SECP224R1 );
case PSA_ECC_CURVE_SECP256R1:
return( MBEDTLS_ECP_DP_SECP256R1 );
case PSA_ECC_CURVE_SECP384R1:
return( MBEDTLS_ECP_DP_SECP384R1 );
case PSA_ECC_CURVE_SECP521R1:
return( MBEDTLS_ECP_DP_SECP521R1 );
case PSA_ECC_CURVE_BRAINPOOL_P256R1:
return( MBEDTLS_ECP_DP_BP256R1 );
case PSA_ECC_CURVE_BRAINPOOL_P384R1:
return( MBEDTLS_ECP_DP_BP384R1 );
case PSA_ECC_CURVE_BRAINPOOL_P512R1:
return( MBEDTLS_ECP_DP_BP512R1 );
case PSA_ECC_CURVE_CURVE25519:
return( MBEDTLS_ECP_DP_CURVE25519 );
case PSA_ECC_CURVE_SECP192K1:
return( MBEDTLS_ECP_DP_SECP192K1 );
case PSA_ECC_CURVE_SECP224K1:
return( MBEDTLS_ECP_DP_SECP224K1 );
case PSA_ECC_CURVE_SECP256K1:
return( MBEDTLS_ECP_DP_SECP256K1 );
case PSA_ECC_CURVE_CURVE448:
return( MBEDTLS_ECP_DP_CURVE448 );
default:
return( MBEDTLS_ECP_DP_NONE );
}
}
#endif /* defined(MBEDTLS_ECP_C) */
static psa_status_t prepare_raw_data_slot( psa_key_type_t type,
size_t bits,
struct raw_data *raw )
{
/* Check that the bit size is acceptable for the key type */
switch( type )
{
case PSA_KEY_TYPE_RAW_DATA:
if( bits == 0 )
{
raw->bytes = 0;
raw->data = NULL;
return( PSA_SUCCESS );
}
break;
#if defined(MBEDTLS_MD_C)
case PSA_KEY_TYPE_HMAC:
#endif
case PSA_KEY_TYPE_DERIVE:
break;
#if defined(MBEDTLS_AES_C)
case PSA_KEY_TYPE_AES:
if( bits != 128 && bits != 192 && bits != 256 )
return( PSA_ERROR_INVALID_ARGUMENT );
break;
#endif
#if defined(MBEDTLS_CAMELLIA_C)
case PSA_KEY_TYPE_CAMELLIA:
if( bits != 128 && bits != 192 && bits != 256 )
return( PSA_ERROR_INVALID_ARGUMENT );
break;
#endif
#if defined(MBEDTLS_DES_C)
case PSA_KEY_TYPE_DES:
if( bits != 64 && bits != 128 && bits != 192 )
return( PSA_ERROR_INVALID_ARGUMENT );
break;
#endif
#if defined(MBEDTLS_ARC4_C)
case PSA_KEY_TYPE_ARC4:
if( bits < 8 || bits > 2048 )
return( PSA_ERROR_INVALID_ARGUMENT );
break;
#endif
default:
return( PSA_ERROR_NOT_SUPPORTED );
}
if( bits % 8 != 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
/* Allocate memory for the key */
raw->bytes = PSA_BITS_TO_BYTES( bits );
raw->data = mbedtls_calloc( 1, raw->bytes );
if( raw->data == NULL )
{
raw->bytes = 0;
return( PSA_ERROR_INSUFFICIENT_MEMORY );
}
return( PSA_SUCCESS );
}
#if defined(MBEDTLS_RSA_C) && defined(MBEDTLS_PK_PARSE_C)
static psa_status_t psa_import_rsa_key( mbedtls_pk_context *pk,
mbedtls_rsa_context **p_rsa )
{
if( mbedtls_pk_get_type( pk ) != MBEDTLS_PK_RSA )
return( PSA_ERROR_INVALID_ARGUMENT );
else
{
mbedtls_rsa_context *rsa = mbedtls_pk_rsa( *pk );
size_t bits = mbedtls_rsa_get_bitlen( rsa );
if( bits > PSA_VENDOR_RSA_MAX_KEY_BITS )
return( PSA_ERROR_NOT_SUPPORTED );
*p_rsa = rsa;
return( PSA_SUCCESS );
}
}
#endif /* defined(MBEDTLS_RSA_C) && defined(MBEDTLS_PK_PARSE_C) */
#if defined(MBEDTLS_ECP_C) && defined(MBEDTLS_PK_PARSE_C)
/* Import an elliptic curve parsed by the mbedtls pk module. */
static psa_status_t psa_import_ecp_key( psa_ecc_curve_t expected_curve,
mbedtls_pk_context *pk,
mbedtls_ecp_keypair **p_ecp )
{
if( mbedtls_pk_get_type( pk ) != MBEDTLS_PK_ECKEY )
return( PSA_ERROR_INVALID_ARGUMENT );
else
{
mbedtls_ecp_keypair *ecp = mbedtls_pk_ec( *pk );
psa_ecc_curve_t actual_curve = mbedtls_ecc_group_to_psa( ecp->grp.id );
if( actual_curve != expected_curve )
return( PSA_ERROR_INVALID_ARGUMENT );
*p_ecp = ecp;
return( PSA_SUCCESS );
}
}
#endif /* defined(MBEDTLS_ECP_C) && defined(MBEDTLS_PK_PARSE_C) */
#if defined(MBEDTLS_ECP_C)
/* Import a private key given as a byte string which is the private value
* in big-endian order. */
static psa_status_t psa_import_ec_private_key( psa_ecc_curve_t curve,
const uint8_t *data,
size_t data_length,
mbedtls_ecp_keypair **p_ecp )
{
psa_status_t status = PSA_ERROR_TAMPERING_DETECTED;
mbedtls_ecp_keypair *ecp = NULL;
mbedtls_ecp_group_id grp_id = mbedtls_ecc_group_of_psa( curve );
*p_ecp = NULL;
ecp = mbedtls_calloc( 1, sizeof( mbedtls_ecp_keypair ) );
if( ecp == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
/* Load the group. */
status = mbedtls_to_psa_error(
mbedtls_ecp_group_load( &ecp->grp, grp_id ) );
if( status != PSA_SUCCESS )
goto exit;
/* Load the secret value. */
status = mbedtls_to_psa_error(
mbedtls_mpi_read_binary( &ecp->d, data, data_length ) );
if( status != PSA_SUCCESS )
goto exit;
/* Validate the private key. */
status = mbedtls_to_psa_error(
mbedtls_ecp_check_privkey( &ecp->grp, &ecp->d ) );
if( status != PSA_SUCCESS )
goto exit;
/* Calculate the public key from the private key. */
status = mbedtls_to_psa_error(
mbedtls_ecp_mul( &ecp->grp, &ecp->Q, &ecp->d, &ecp->grp.G,
mbedtls_ctr_drbg_random, &global_data.ctr_drbg ) );
if( status != PSA_SUCCESS )
goto exit;
*p_ecp = ecp;
return( PSA_SUCCESS );
exit:
if( ecp != NULL )
{
mbedtls_ecp_keypair_free( ecp );
mbedtls_free( ecp );
}
return( status );
}
#endif /* defined(MBEDTLS_ECP_C) */
psa_status_t psa_import_key( psa_key_slot_t key,
psa_key_type_t type,
const uint8_t *data,
size_t data_length )
{
key_slot_t *slot;
psa_status_t status = PSA_SUCCESS;
status = psa_get_empty_key_slot( key, &slot );
if( status != PSA_SUCCESS )
return( status );
if( key_type_is_raw_bytes( type ) )
{
/* Ensure that a bytes-to-bit conversion won't overflow. */
if( data_length > SIZE_MAX / 8 )
return( PSA_ERROR_NOT_SUPPORTED );
status = prepare_raw_data_slot( type,
PSA_BYTES_TO_BITS( data_length ),
&slot->data.raw );
if( status != PSA_SUCCESS )
return( status );
if( data_length != 0 )
memcpy( slot->data.raw.data, data, data_length );
}
else
#if defined(MBEDTLS_ECP_C)
if( PSA_KEY_TYPE_IS_ECC_KEYPAIR( type ) )
{
status = psa_import_ec_private_key( PSA_KEY_TYPE_GET_CURVE( type ),
data, data_length,
&slot->data.ecp );
if( status != PSA_SUCCESS )
return( status );
}
else
#endif /* MBEDTLS_ECP_C */
#if defined(MBEDTLS_PK_PARSE_C)
if( PSA_KEY_TYPE_IS_RSA( type ) || PSA_KEY_TYPE_IS_ECC( type ) )
{
int ret;
mbedtls_pk_context pk;
mbedtls_pk_init( &pk );
/* Parse the data. */
if( PSA_KEY_TYPE_IS_KEYPAIR( type ) )
ret = mbedtls_pk_parse_key( &pk, data, data_length, NULL, 0 );
else
ret = mbedtls_pk_parse_public_key( &pk, data, data_length );
if( ret != 0 )
return( mbedtls_to_psa_error( ret ) );
/* We have something that the pkparse module recognizes.
* If it has the expected type and passes any type-specific
* checks, store it. */
#if defined(MBEDTLS_RSA_C)
if( PSA_KEY_TYPE_IS_RSA( type ) )
status = psa_import_rsa_key( &pk, &slot->data.rsa );
else
#endif /* MBEDTLS_RSA_C */
#if defined(MBEDTLS_ECP_C)
if( PSA_KEY_TYPE_IS_ECC( type ) )
status = psa_import_ecp_key( PSA_KEY_TYPE_GET_CURVE( type ),
&pk, &slot->data.ecp );
else
#endif /* MBEDTLS_ECP_C */
{
status = PSA_ERROR_NOT_SUPPORTED;
}
/* Free the content of the pk object only on error. On success,
* the content of the object has been stored in the slot. */
if( status != PSA_SUCCESS )
{
mbedtls_pk_free( &pk );
return( status );
}
}
else
#endif /* defined(MBEDTLS_PK_PARSE_C) */
{
return( PSA_ERROR_NOT_SUPPORTED );
}
slot->type = type;
return( PSA_SUCCESS );
}
psa_status_t psa_destroy_key( psa_key_slot_t key )
{
key_slot_t *slot;
psa_status_t status;
status = psa_get_key_slot( key, &slot );
if( status != PSA_SUCCESS )
return( status );
if( slot->type == PSA_KEY_TYPE_NONE )
{
/* No key material to clean, but do zeroize the slot below to wipe
* metadata such as policies. */
}
else if( key_type_is_raw_bytes( slot->type ) )
{
mbedtls_free( slot->data.raw.data );
}
else
#if defined(MBEDTLS_RSA_C)
if( PSA_KEY_TYPE_IS_RSA( slot->type ) )
{
mbedtls_rsa_free( slot->data.rsa );
mbedtls_free( slot->data.rsa );
}
else
#endif /* defined(MBEDTLS_RSA_C) */
#if defined(MBEDTLS_ECP_C)
if( PSA_KEY_TYPE_IS_ECC( slot->type ) )
{
mbedtls_ecp_keypair_free( slot->data.ecp );
mbedtls_free( slot->data.ecp );
}
else
#endif /* defined(MBEDTLS_ECP_C) */
{
/* Shouldn't happen: the key type is not any type that we
* put in. */
return( PSA_ERROR_TAMPERING_DETECTED );
}
mbedtls_zeroize( slot, sizeof( *slot ) );
return( PSA_SUCCESS );
}
/* Return the size of the key in the given slot, in bits. */
static size_t psa_get_key_bits( const key_slot_t *slot )
{
if( key_type_is_raw_bytes( slot->type ) )
return( slot->data.raw.bytes * 8 );
#if defined(MBEDTLS_RSA_C)
if( PSA_KEY_TYPE_IS_RSA( slot->type ) )
return( mbedtls_rsa_get_bitlen( slot->data.rsa ) );
#endif /* defined(MBEDTLS_RSA_C) */
#if defined(MBEDTLS_ECP_C)
if( PSA_KEY_TYPE_IS_ECC( slot->type ) )
return( slot->data.ecp->grp.pbits );
#endif /* defined(MBEDTLS_ECP_C) */
/* Shouldn't happen except on an empty slot. */
return( 0 );
}
psa_status_t psa_get_key_information( psa_key_slot_t key,
psa_key_type_t *type,
size_t *bits )
{
key_slot_t *slot;
psa_status_t status;
if( type != NULL )
*type = 0;
if( bits != NULL )
*bits = 0;
status = psa_get_key_slot( key, &slot );
if( status != PSA_SUCCESS )
return( status );
if( slot->type == PSA_KEY_TYPE_NONE )
return( PSA_ERROR_EMPTY_SLOT );
if( type != NULL )
*type = slot->type;
if( bits != NULL )
*bits = psa_get_key_bits( slot );
return( PSA_SUCCESS );
}
static psa_status_t psa_internal_export_key( psa_key_slot_t key,
uint8_t *data,
size_t data_size,
size_t *data_length,
int export_public_key )
{
key_slot_t *slot;
psa_status_t status;
/* Exporting a public key doesn't require a usage flag. If we're
* called by psa_export_public_key(), don't require the EXPORT flag.
* If we're called by psa_export_key(), do require the EXPORT flag;
* if the key turns out to be public key object, psa_get_key_from_slot()
* will ignore this flag. */
psa_key_usage_t usage = export_public_key ? 0 : PSA_KEY_USAGE_EXPORT;
/* Set the key to empty now, so that even when there are errors, we always
* set data_length to a value between 0 and data_size. On error, setting
* the key to empty is a good choice because an empty key representation is
* unlikely to be accepted anywhere. */
*data_length = 0;
status = psa_get_key_from_slot( key, &slot, usage, 0 );
if( status != PSA_SUCCESS )
return( status );
if( export_public_key && ! PSA_KEY_TYPE_IS_ASYMMETRIC( slot->type ) )
return( PSA_ERROR_INVALID_ARGUMENT );
if( key_type_is_raw_bytes( slot->type ) )
{
if( slot->data.raw.bytes > data_size )
return( PSA_ERROR_BUFFER_TOO_SMALL );
if( slot->data.raw.bytes != 0 )
memcpy( data, slot->data.raw.data, slot->data.raw.bytes );
*data_length = slot->data.raw.bytes;
return( PSA_SUCCESS );
}
else
{
#if defined(MBEDTLS_PK_WRITE_C)
if( PSA_KEY_TYPE_IS_RSA( slot->type ) ||
PSA_KEY_TYPE_IS_ECC( slot->type ) )
{
mbedtls_pk_context pk;
int ret;
if( PSA_KEY_TYPE_IS_RSA( slot->type ) )
{
#if defined(MBEDTLS_RSA_C)
mbedtls_pk_init( &pk );
pk.pk_info = &mbedtls_rsa_info;
pk.pk_ctx = slot->data.rsa;
#else
return( PSA_ERROR_NOT_SUPPORTED );
#endif
}
else
{
#if defined(MBEDTLS_ECP_C)
mbedtls_pk_init( &pk );
pk.pk_info = &mbedtls_eckey_info;
pk.pk_ctx = slot->data.ecp;
#else
return( PSA_ERROR_NOT_SUPPORTED );
#endif
}
if( export_public_key || PSA_KEY_TYPE_IS_PUBLIC_KEY( slot->type ) )
ret = mbedtls_pk_write_pubkey_der( &pk, data, data_size );
else
ret = mbedtls_pk_write_key_der( &pk, data, data_size );
if( ret < 0 )
{
/* If data_size is 0 then data may be NULL and then the
* call to memset would have undefined behavior. */
if( data_size != 0 )
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
#endif /* defined(MBEDTLS_PK_WRITE_C) */
{
/* This shouldn't happen in the reference implementation, but
it is valid for a special-purpose implementation to omit
support for exporting certain key types. */
return( PSA_ERROR_NOT_SUPPORTED );
}
}
}
psa_status_t psa_export_key( psa_key_slot_t key,
uint8_t *data,
size_t data_size,
size_t *data_length )
{
return( psa_internal_export_key( key, data, data_size,
data_length, 0 ) );
}
psa_status_t psa_export_public_key( psa_key_slot_t key,
uint8_t *data,
size_t data_size,
size_t *data_length )
{
return( psa_internal_export_key( key, data, data_size,
data_length, 1 ) );
}
/****************************************************************/
/* Message digests */
/****************************************************************/
static const mbedtls_md_info_t *mbedtls_md_info_from_psa( psa_algorithm_t alg )
{
switch( alg )
{
#if defined(MBEDTLS_MD2_C)
case PSA_ALG_MD2:
return( &mbedtls_md2_info );
#endif
#if defined(MBEDTLS_MD4_C)
case PSA_ALG_MD4:
return( &mbedtls_md4_info );
#endif
#if defined(MBEDTLS_MD5_C)
case PSA_ALG_MD5:
return( &mbedtls_md5_info );
#endif
#if defined(MBEDTLS_RIPEMD160_C)
case PSA_ALG_RIPEMD160:
return( &mbedtls_ripemd160_info );
#endif
#if defined(MBEDTLS_SHA1_C)
case PSA_ALG_SHA_1:
return( &mbedtls_sha1_info );
#endif
#if defined(MBEDTLS_SHA256_C)
case PSA_ALG_SHA_224:
return( &mbedtls_sha224_info );
case PSA_ALG_SHA_256:
return( &mbedtls_sha256_info );
#endif
#if defined(MBEDTLS_SHA512_C)
case PSA_ALG_SHA_384:
return( &mbedtls_sha384_info );
case PSA_ALG_SHA_512:
return( &mbedtls_sha512_info );
#endif
default:
return( NULL );
}
}
psa_status_t psa_hash_abort( psa_hash_operation_t *operation )
{
switch( operation->alg )
{
case 0:
/* The object has (apparently) been initialized but it is not
* in use. It's ok to call abort on such an object, and there's
* nothing to do. */
break;
#if defined(MBEDTLS_MD2_C)
case PSA_ALG_MD2:
mbedtls_md2_free( &operation->ctx.md2 );
break;
#endif
#if defined(MBEDTLS_MD4_C)
case PSA_ALG_MD4:
mbedtls_md4_free( &operation->ctx.md4 );
break;
#endif
#if defined(MBEDTLS_MD5_C)
case PSA_ALG_MD5:
mbedtls_md5_free( &operation->ctx.md5 );
break;
#endif
#if defined(MBEDTLS_RIPEMD160_C)
case PSA_ALG_RIPEMD160:
mbedtls_ripemd160_free( &operation->ctx.ripemd160 );
break;
#endif
#if defined(MBEDTLS_SHA1_C)
case PSA_ALG_SHA_1:
mbedtls_sha1_free( &operation->ctx.sha1 );
break;
#endif
#if defined(MBEDTLS_SHA256_C)
case PSA_ALG_SHA_224:
case PSA_ALG_SHA_256:
mbedtls_sha256_free( &operation->ctx.sha256 );
break;
#endif
#if defined(MBEDTLS_SHA512_C)
case PSA_ALG_SHA_384:
case PSA_ALG_SHA_512:
mbedtls_sha512_free( &operation->ctx.sha512 );
break;
#endif
default:
return( PSA_ERROR_BAD_STATE );
}
operation->alg = 0;
return( PSA_SUCCESS );
}
psa_status_t psa_hash_setup( psa_hash_operation_t *operation,
psa_algorithm_t alg )
{
int ret;
operation->alg = 0;
switch( alg )
{
#if defined(MBEDTLS_MD2_C)
case PSA_ALG_MD2:
mbedtls_md2_init( &operation->ctx.md2 );
ret = mbedtls_md2_starts_ret( &operation->ctx.md2 );
break;
#endif
#if defined(MBEDTLS_MD4_C)
case PSA_ALG_MD4:
mbedtls_md4_init( &operation->ctx.md4 );
ret = mbedtls_md4_starts_ret( &operation->ctx.md4 );
break;
#endif
#if defined(MBEDTLS_MD5_C)
case PSA_ALG_MD5:
mbedtls_md5_init( &operation->ctx.md5 );
ret = mbedtls_md5_starts_ret( &operation->ctx.md5 );
break;
#endif
#if defined(MBEDTLS_RIPEMD160_C)
case PSA_ALG_RIPEMD160:
mbedtls_ripemd160_init( &operation->ctx.ripemd160 );
ret = mbedtls_ripemd160_starts_ret( &operation->ctx.ripemd160 );
break;
#endif
#if defined(MBEDTLS_SHA1_C)
case PSA_ALG_SHA_1:
mbedtls_sha1_init( &operation->ctx.sha1 );
ret = mbedtls_sha1_starts_ret( &operation->ctx.sha1 );
break;
#endif
#if defined(MBEDTLS_SHA256_C)
case PSA_ALG_SHA_224:
mbedtls_sha256_init( &operation->ctx.sha256 );
ret = mbedtls_sha256_starts_ret( &operation->ctx.sha256, 1 );
break;
case PSA_ALG_SHA_256:
mbedtls_sha256_init( &operation->ctx.sha256 );
ret = mbedtls_sha256_starts_ret( &operation->ctx.sha256, 0 );
break;
#endif
#if defined(MBEDTLS_SHA512_C)
case PSA_ALG_SHA_384:
mbedtls_sha512_init( &operation->ctx.sha512 );
ret = mbedtls_sha512_starts_ret( &operation->ctx.sha512, 1 );
break;
case PSA_ALG_SHA_512:
mbedtls_sha512_init( &operation->ctx.sha512 );
ret = mbedtls_sha512_starts_ret( &operation->ctx.sha512, 0 );
break;
#endif
default:
return( PSA_ALG_IS_HASH( alg ) ?
PSA_ERROR_NOT_SUPPORTED :
PSA_ERROR_INVALID_ARGUMENT );
}
if( ret == 0 )
operation->alg = alg;
else
psa_hash_abort( operation );
return( mbedtls_to_psa_error( ret ) );
}
psa_status_t psa_hash_update( psa_hash_operation_t *operation,
const uint8_t *input,
size_t input_length )
{
int ret;
/* Don't require hash implementations to behave correctly on a
* zero-length input, which may have an invalid pointer. */
if( input_length == 0 )
return( PSA_SUCCESS );
switch( operation->alg )
{
#if defined(MBEDTLS_MD2_C)
case PSA_ALG_MD2:
ret = mbedtls_md2_update_ret( &operation->ctx.md2,
input, input_length );
break;
#endif
#if defined(MBEDTLS_MD4_C)
case PSA_ALG_MD4:
ret = mbedtls_md4_update_ret( &operation->ctx.md4,
input, input_length );
break;
#endif
#if defined(MBEDTLS_MD5_C)
case PSA_ALG_MD5:
ret = mbedtls_md5_update_ret( &operation->ctx.md5,
input, input_length );
break;
#endif
#if defined(MBEDTLS_RIPEMD160_C)
case PSA_ALG_RIPEMD160:
ret = mbedtls_ripemd160_update_ret( &operation->ctx.ripemd160,
input, input_length );
break;
#endif
#if defined(MBEDTLS_SHA1_C)
case PSA_ALG_SHA_1:
ret = mbedtls_sha1_update_ret( &operation->ctx.sha1,
input, input_length );
break;
#endif
#if defined(MBEDTLS_SHA256_C)
case PSA_ALG_SHA_224:
case PSA_ALG_SHA_256:
ret = mbedtls_sha256_update_ret( &operation->ctx.sha256,
input, input_length );
break;
#endif
#if defined(MBEDTLS_SHA512_C)
case PSA_ALG_SHA_384:
case PSA_ALG_SHA_512:
ret = mbedtls_sha512_update_ret( &operation->ctx.sha512,
input, input_length );
break;
#endif
default:
ret = MBEDTLS_ERR_MD_BAD_INPUT_DATA;
break;
}
if( ret != 0 )
psa_hash_abort( operation );
return( mbedtls_to_psa_error( ret ) );
}
psa_status_t psa_hash_finish( psa_hash_operation_t *operation,
uint8_t *hash,
size_t hash_size,
size_t *hash_length )
{
psa_status_t status;
int ret;
size_t actual_hash_length = PSA_HASH_SIZE( operation->alg );
/* Fill the output buffer with something that isn't a valid hash
* (barring an attack on the hash and deliberately-crafted input),
* in case the caller doesn't check the return status properly. */
*hash_length = hash_size;
/* If hash_size is 0 then hash may be NULL and then the
* call to memset would have undefined behavior. */
if( hash_size != 0 )
memset( hash, '!', hash_size );
if( hash_size < actual_hash_length )
{
status = PSA_ERROR_BUFFER_TOO_SMALL;
goto exit;
}
switch( operation->alg )
{
#if defined(MBEDTLS_MD2_C)
case PSA_ALG_MD2:
ret = mbedtls_md2_finish_ret( &operation->ctx.md2, hash );
break;
#endif
#if defined(MBEDTLS_MD4_C)
case PSA_ALG_MD4:
ret = mbedtls_md4_finish_ret( &operation->ctx.md4, hash );
break;
#endif
#if defined(MBEDTLS_MD5_C)
case PSA_ALG_MD5:
ret = mbedtls_md5_finish_ret( &operation->ctx.md5, hash );
break;
#endif
#if defined(MBEDTLS_RIPEMD160_C)
case PSA_ALG_RIPEMD160:
ret = mbedtls_ripemd160_finish_ret( &operation->ctx.ripemd160, hash );
break;
#endif
#if defined(MBEDTLS_SHA1_C)
case PSA_ALG_SHA_1:
ret = mbedtls_sha1_finish_ret( &operation->ctx.sha1, hash );
break;
#endif
#if defined(MBEDTLS_SHA256_C)
case PSA_ALG_SHA_224:
case PSA_ALG_SHA_256:
ret = mbedtls_sha256_finish_ret( &operation->ctx.sha256, hash );
break;
#endif
#if defined(MBEDTLS_SHA512_C)
case PSA_ALG_SHA_384:
case PSA_ALG_SHA_512:
ret = mbedtls_sha512_finish_ret( &operation->ctx.sha512, hash );
break;
#endif
default:
ret = MBEDTLS_ERR_MD_BAD_INPUT_DATA;
break;
}
status = mbedtls_to_psa_error( ret );
exit:
if( status == PSA_SUCCESS )
{
*hash_length = actual_hash_length;
return( psa_hash_abort( operation ) );
}
else
{
psa_hash_abort( operation );
return( status );
}
}
psa_status_t psa_hash_verify( psa_hash_operation_t *operation,
const uint8_t *hash,
size_t hash_length )
{
uint8_t actual_hash[MBEDTLS_MD_MAX_SIZE];
size_t actual_hash_length;
psa_status_t status = psa_hash_finish( operation,
actual_hash, sizeof( actual_hash ),
&actual_hash_length );
if( status != PSA_SUCCESS )
return( status );
if( actual_hash_length != hash_length )
return( PSA_ERROR_INVALID_SIGNATURE );
if( safer_memcmp( hash, actual_hash, actual_hash_length ) != 0 )
return( PSA_ERROR_INVALID_SIGNATURE );
return( PSA_SUCCESS );
}
/****************************************************************/
/* MAC */
/****************************************************************/
static const mbedtls_cipher_info_t *mbedtls_cipher_info_from_psa(
psa_algorithm_t alg,
psa_key_type_t key_type,
size_t key_bits,
mbedtls_cipher_id_t* cipher_id )
{
mbedtls_cipher_mode_t mode;
mbedtls_cipher_id_t cipher_id_tmp;
if( PSA_ALG_IS_AEAD( alg ) )
alg = PSA_ALG_AEAD_WITH_TAG_LENGTH( alg, 0 );
if( PSA_ALG_IS_CIPHER( alg ) || PSA_ALG_IS_AEAD( alg ) )
{
switch( alg )
{
case PSA_ALG_ARC4:
mode = MBEDTLS_MODE_STREAM;
break;
case PSA_ALG_CTR:
mode = MBEDTLS_MODE_CTR;
break;
case PSA_ALG_CFB:
mode = MBEDTLS_MODE_CFB;
break;
case PSA_ALG_OFB:
mode = MBEDTLS_MODE_OFB;
break;
case PSA_ALG_CBC_NO_PADDING:
mode = MBEDTLS_MODE_CBC;
break;
case PSA_ALG_CBC_PKCS7:
mode = MBEDTLS_MODE_CBC;
break;
case PSA_ALG_AEAD_WITH_TAG_LENGTH( PSA_ALG_CCM, 0 ):
mode = MBEDTLS_MODE_CCM;
break;
case PSA_ALG_AEAD_WITH_TAG_LENGTH( PSA_ALG_GCM, 0 ):
mode = MBEDTLS_MODE_GCM;
break;
default:
return( NULL );
}
}
else if( alg == PSA_ALG_CMAC )
mode = MBEDTLS_MODE_ECB;
else if( alg == PSA_ALG_GMAC )
mode = MBEDTLS_MODE_GCM;
else
return( NULL );
switch( key_type )
{
case PSA_KEY_TYPE_AES:
cipher_id_tmp = MBEDTLS_CIPHER_ID_AES;
break;
case PSA_KEY_TYPE_DES:
/* key_bits is 64 for Single-DES, 128 for two-key Triple-DES,
* and 192 for three-key Triple-DES. */
if( key_bits == 64 )
cipher_id_tmp = MBEDTLS_CIPHER_ID_DES;
else
cipher_id_tmp = MBEDTLS_CIPHER_ID_3DES;
/* mbedtls doesn't recognize two-key Triple-DES as an algorithm,
* but two-key Triple-DES is functionally three-key Triple-DES
* with K1=K3, so that's how we present it to mbedtls. */
if( key_bits == 128 )
key_bits = 192;
break;
case PSA_KEY_TYPE_CAMELLIA:
cipher_id_tmp = MBEDTLS_CIPHER_ID_CAMELLIA;
break;
case PSA_KEY_TYPE_ARC4:
cipher_id_tmp = MBEDTLS_CIPHER_ID_ARC4;
break;
default:
return( NULL );
}
if( cipher_id != NULL )
*cipher_id = cipher_id_tmp;
return( mbedtls_cipher_info_from_values( cipher_id_tmp,
(int) key_bits, mode ) );
}
static size_t psa_get_hash_block_size( psa_algorithm_t alg )
{
switch( alg )
{
case PSA_ALG_MD2:
return( 16 );
case PSA_ALG_MD4:
return( 64 );
case PSA_ALG_MD5:
return( 64 );
case PSA_ALG_RIPEMD160:
return( 64 );
case PSA_ALG_SHA_1:
return( 64 );
case PSA_ALG_SHA_224:
return( 64 );
case PSA_ALG_SHA_256:
return( 64 );
case PSA_ALG_SHA_384:
return( 128 );
case PSA_ALG_SHA_512:
return( 128 );
default:
return( 0 );
}
}
/* Initialize the MAC operation structure. Once this function has been
* called, psa_mac_abort can run and will do the right thing. */
static psa_status_t psa_mac_init( psa_mac_operation_t *operation,
psa_algorithm_t alg )
{
psa_status_t status = PSA_ERROR_NOT_SUPPORTED;
operation->alg = alg;
operation->key_set = 0;
operation->iv_set = 0;
operation->iv_required = 0;
operation->has_input = 0;
operation->is_sign = 0;
#if defined(MBEDTLS_CMAC_C)
if( alg == PSA_ALG_CMAC )
{
operation->iv_required = 0;
mbedtls_cipher_init( &operation->ctx.cmac );
status = PSA_SUCCESS;
}
else
#endif /* MBEDTLS_CMAC_C */
#if defined(MBEDTLS_MD_C)
if( PSA_ALG_IS_HMAC( operation->alg ) )
{
/* We'll set up the hash operation later in psa_hmac_setup_internal. */
operation->ctx.hmac.hash_ctx.alg = 0;
status = PSA_SUCCESS;
}
else
#endif /* MBEDTLS_MD_C */
{
if( ! PSA_ALG_IS_MAC( alg ) )
status = PSA_ERROR_INVALID_ARGUMENT;
}
if( status != PSA_SUCCESS )
memset( operation, 0, sizeof( *operation ) );
return( status );
}
#if defined(MBEDTLS_MD_C)
static psa_status_t psa_hmac_abort_internal( psa_hmac_internal_data *hmac )
{
mbedtls_zeroize( hmac->opad, sizeof( hmac->opad ) );
return( psa_hash_abort( &hmac->hash_ctx ) );
}
#endif /* MBEDTLS_MD_C */
psa_status_t psa_mac_abort( psa_mac_operation_t *operation )
{
if( operation->alg == 0 )
{
/* The object has (apparently) been initialized but it is not
* in use. It's ok to call abort on such an object, and there's
* nothing to do. */
return( PSA_SUCCESS );
}
else
#if defined(MBEDTLS_CMAC_C)
if( operation->alg == PSA_ALG_CMAC )
{
mbedtls_cipher_free( &operation->ctx.cmac );
}
else
#endif /* MBEDTLS_CMAC_C */
#if defined(MBEDTLS_MD_C)
if( PSA_ALG_IS_HMAC( operation->alg ) )
{
psa_hmac_abort_internal( &operation->ctx.hmac );
}
else
#endif /* MBEDTLS_MD_C */
{
/* Sanity check (shouldn't happen: operation->alg should
* always have been initialized to a valid value). */
goto bad_state;
}
operation->alg = 0;
operation->key_set = 0;
operation->iv_set = 0;
operation->iv_required = 0;
operation->has_input = 0;
operation->is_sign = 0;
return( PSA_SUCCESS );
bad_state:
/* If abort is called on an uninitialized object, we can't trust
* anything. Wipe the object in case it contains confidential data.
* This may result in a memory leak if a pointer gets overwritten,
* but it's too late to do anything about this. */
memset( operation, 0, sizeof( *operation ) );
return( PSA_ERROR_BAD_STATE );
}
#if defined(MBEDTLS_CMAC_C)
static int psa_cmac_setup( psa_mac_operation_t *operation,
size_t key_bits,
key_slot_t *slot,
const mbedtls_cipher_info_t *cipher_info )
{
int ret;
operation->mac_size = cipher_info->block_size;
ret = mbedtls_cipher_setup( &operation->ctx.cmac, cipher_info );
if( ret != 0 )
return( ret );
ret = mbedtls_cipher_cmac_starts( &operation->ctx.cmac,
slot->data.raw.data,
key_bits );
return( ret );
}
#endif /* MBEDTLS_CMAC_C */
#if defined(MBEDTLS_MD_C)
static psa_status_t psa_hmac_setup_internal( psa_hmac_internal_data *hmac,
const uint8_t *key,
size_t key_length,
psa_algorithm_t hash_alg )
{
unsigned char ipad[PSA_HMAC_MAX_HASH_BLOCK_SIZE];
size_t i;
size_t hash_size = PSA_HASH_SIZE( hash_alg );
size_t block_size = psa_get_hash_block_size( hash_alg );
psa_status_t status;
/* Sanity checks on block_size, to guarantee that there won't be a buffer
* overflow below. This should never trigger if the hash algorithm
* is implemented correctly. */
/* The size checks against the ipad and opad buffers cannot be written
* `block_size > sizeof( ipad ) || block_size > sizeof( hmac->opad )`
* because that triggers -Wlogical-op on GCC 7.3. */
if( block_size > sizeof( ipad ) )
return( PSA_ERROR_NOT_SUPPORTED );
if( block_size > sizeof( hmac->opad ) )
return( PSA_ERROR_NOT_SUPPORTED );
if( block_size < hash_size )
return( PSA_ERROR_NOT_SUPPORTED );
if( key_length > block_size )
{
status = psa_hash_setup( &hmac->hash_ctx, hash_alg );
if( status != PSA_SUCCESS )
goto cleanup;
status = psa_hash_update( &hmac->hash_ctx, key, key_length );
if( status != PSA_SUCCESS )
goto cleanup;
status = psa_hash_finish( &hmac->hash_ctx,
ipad, sizeof( ipad ), &key_length );
if( status != PSA_SUCCESS )
goto cleanup;
}
/* A 0-length key is not commonly used in HMAC when used as a MAC,
* but it is permitted. It is common when HMAC is used in HKDF, for
* example. Don't call `memcpy` in the 0-length because `key` could be
* an invalid pointer which would make the behavior undefined. */
else if( key_length != 0 )
memcpy( ipad, key, key_length );
/* ipad contains the key followed by garbage. Xor and fill with 0x36
* to create the ipad value. */
for( i = 0; i < key_length; i++ )
ipad[i] ^= 0x36;
memset( ipad + key_length, 0x36, block_size - key_length );
/* Copy the key material from ipad to opad, flipping the requisite bits,
* and filling the rest of opad with the requisite constant. */
for( i = 0; i < key_length; i++ )
hmac->opad[i] = ipad[i] ^ 0x36 ^ 0x5C;
memset( hmac->opad + key_length, 0x5C, block_size - key_length );
status = psa_hash_setup( &hmac->hash_ctx, hash_alg );
if( status != PSA_SUCCESS )
goto cleanup;
status = psa_hash_update( &hmac->hash_ctx, ipad, block_size );
cleanup:
mbedtls_zeroize( ipad, key_length );
return( status );
}
#endif /* MBEDTLS_MD_C */
static psa_status_t psa_mac_setup( psa_mac_operation_t *operation,
psa_key_slot_t key,
psa_algorithm_t alg,
int is_sign )
{
psa_status_t status;
key_slot_t *slot;
size_t key_bits;
psa_key_usage_t usage =
is_sign ? PSA_KEY_USAGE_SIGN : PSA_KEY_USAGE_VERIFY;
unsigned char truncated = PSA_MAC_TRUNCATED_LENGTH( alg );
psa_algorithm_t full_length_alg = PSA_ALG_FULL_LENGTH_MAC( alg );
status = psa_mac_init( operation, full_length_alg );
if( status != PSA_SUCCESS )
return( status );
if( is_sign )
operation->is_sign = 1;
status = psa_get_key_from_slot( key, &slot, usage, alg );
if( status != PSA_SUCCESS )
goto exit;
key_bits = psa_get_key_bits( slot );
#if defined(MBEDTLS_CMAC_C)
if( full_length_alg == PSA_ALG_CMAC )
{
const mbedtls_cipher_info_t *cipher_info =
mbedtls_cipher_info_from_psa( full_length_alg,
slot->type, key_bits, NULL );
int ret;
if( cipher_info == NULL )
{
status = PSA_ERROR_NOT_SUPPORTED;
goto exit;
}
operation->mac_size = cipher_info->block_size;
ret = psa_cmac_setup( operation, key_bits, slot, cipher_info );
status = mbedtls_to_psa_error( ret );
}
else
#endif /* MBEDTLS_CMAC_C */
#if defined(MBEDTLS_MD_C)
if( PSA_ALG_IS_HMAC( full_length_alg ) )
{
psa_algorithm_t hash_alg = PSA_ALG_HMAC_GET_HASH( alg );
if( hash_alg == 0 )
{
status = PSA_ERROR_NOT_SUPPORTED;
goto exit;
}
operation->mac_size = PSA_HASH_SIZE( hash_alg );
/* Sanity check. This shouldn't fail on a valid configuration. */
if( operation->mac_size == 0 ||
operation->mac_size > sizeof( operation->ctx.hmac.opad ) )
{
status = PSA_ERROR_NOT_SUPPORTED;
goto exit;
}
if( slot->type != PSA_KEY_TYPE_HMAC )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
status = psa_hmac_setup_internal( &operation->ctx.hmac,
slot->data.raw.data,
slot->data.raw.bytes,
hash_alg );
}
else
#endif /* MBEDTLS_MD_C */
{
status = PSA_ERROR_NOT_SUPPORTED;
}
if( truncated == 0 )
{
/* The "normal" case: untruncated algorithm. Nothing to do. */
}
else if( truncated < 4 )
{
/* A very short MAC is too short for security since it can be
* brute-forced. Ancient protocols with 32-bit MACs do exist,
* so we make this our minimum, even though 32 bits is still
* too small for security. */
status = PSA_ERROR_NOT_SUPPORTED;
}
else if( truncated > operation->mac_size )
{
/* It's impossible to "truncate" to a larger length. */
status = PSA_ERROR_INVALID_ARGUMENT;
}
else
operation->mac_size = truncated;
exit:
if( status != PSA_SUCCESS )
{
psa_mac_abort( operation );
}
else
{
operation->key_set = 1;
}
return( status );
}
psa_status_t psa_mac_sign_setup( psa_mac_operation_t *operation,
psa_key_slot_t key,
psa_algorithm_t alg )
{
return( psa_mac_setup( operation, key, alg, 1 ) );
}
psa_status_t psa_mac_verify_setup( psa_mac_operation_t *operation,
psa_key_slot_t key,
psa_algorithm_t alg )
{
return( psa_mac_setup( operation, key, alg, 0 ) );
}
psa_status_t psa_mac_update( psa_mac_operation_t *operation,
const uint8_t *input,
size_t input_length )
{
psa_status_t status = PSA_ERROR_BAD_STATE;
if( ! operation->key_set )
goto cleanup;
if( operation->iv_required && ! operation->iv_set )
goto cleanup;
operation->has_input = 1;
#if defined(MBEDTLS_CMAC_C)
if( operation->alg == PSA_ALG_CMAC )
{
int ret = mbedtls_cipher_cmac_update( &operation->ctx.cmac,
input, input_length );
status = mbedtls_to_psa_error( ret );
}
else
#endif /* MBEDTLS_CMAC_C */
#if defined(MBEDTLS_MD_C)
if( PSA_ALG_IS_HMAC( operation->alg ) )
{
status = psa_hash_update( &operation->ctx.hmac.hash_ctx, input,
input_length );
}
else
#endif /* MBEDTLS_MD_C */
{
/* This shouldn't happen if `operation` was initialized by
* a setup function. */
status = PSA_ERROR_BAD_STATE;
}
cleanup:
if( status != PSA_SUCCESS )
psa_mac_abort( operation );
return( status );
}
#if defined(MBEDTLS_MD_C)
static psa_status_t psa_hmac_finish_internal( psa_hmac_internal_data *hmac,
uint8_t *mac,
size_t mac_size )
{
unsigned char tmp[MBEDTLS_MD_MAX_SIZE];
psa_algorithm_t hash_alg = hmac->hash_ctx.alg;
size_t hash_size = 0;
size_t block_size = psa_get_hash_block_size( hash_alg );
psa_status_t status;
status = psa_hash_finish( &hmac->hash_ctx, tmp, sizeof( tmp ), &hash_size );
if( status != PSA_SUCCESS )
return( status );
/* From here on, tmp needs to be wiped. */
status = psa_hash_setup( &hmac->hash_ctx, hash_alg );
if( status != PSA_SUCCESS )
goto exit;
status = psa_hash_update( &hmac->hash_ctx, hmac->opad, block_size );
if( status != PSA_SUCCESS )
goto exit;
status = psa_hash_update( &hmac->hash_ctx, tmp, hash_size );
if( status != PSA_SUCCESS )
goto exit;
status = psa_hash_finish( &hmac->hash_ctx, tmp, sizeof( tmp ), &hash_size );
if( status != PSA_SUCCESS )
goto exit;
memcpy( mac, tmp, mac_size );
exit:
mbedtls_zeroize( tmp, hash_size );
return( status );
}
#endif /* MBEDTLS_MD_C */
static psa_status_t psa_mac_finish_internal( psa_mac_operation_t *operation,
uint8_t *mac,
size_t mac_size )
{
if( ! operation->key_set )
return( PSA_ERROR_BAD_STATE );
if( operation->iv_required && ! operation->iv_set )
return( PSA_ERROR_BAD_STATE );
if( mac_size < operation->mac_size )
return( PSA_ERROR_BUFFER_TOO_SMALL );
#if defined(MBEDTLS_CMAC_C)
if( operation->alg == PSA_ALG_CMAC )
{
uint8_t tmp[PSA_MAX_BLOCK_CIPHER_BLOCK_SIZE];
int ret = mbedtls_cipher_cmac_finish( &operation->ctx.cmac, tmp );
if( ret == 0 )
memcpy( mac, tmp, operation->mac_size );
mbedtls_zeroize( tmp, sizeof( tmp ) );
return( mbedtls_to_psa_error( ret ) );
}
else
#endif /* MBEDTLS_CMAC_C */
#if defined(MBEDTLS_MD_C)
if( PSA_ALG_IS_HMAC( operation->alg ) )
{
return( psa_hmac_finish_internal( &operation->ctx.hmac,
mac, operation->mac_size ) );
}
else
#endif /* MBEDTLS_MD_C */
{
/* This shouldn't happen if `operation` was initialized by
* a setup function. */
return( PSA_ERROR_BAD_STATE );
}
}
psa_status_t psa_mac_sign_finish( psa_mac_operation_t *operation,
uint8_t *mac,
size_t mac_size,
size_t *mac_length )
{
psa_status_t status;
/* Fill the output buffer with something that isn't a valid mac
* (barring an attack on the mac and deliberately-crafted input),
* in case the caller doesn't check the return status properly. */
*mac_length = mac_size;
/* If mac_size is 0 then mac may be NULL and then the
* call to memset would have undefined behavior. */
if( mac_size != 0 )
memset( mac, '!', mac_size );
if( ! operation->is_sign )
{
status = PSA_ERROR_BAD_STATE;
goto cleanup;
}
status = psa_mac_finish_internal( operation, mac, mac_size );
cleanup:
if( status == PSA_SUCCESS )
{
status = psa_mac_abort( operation );
if( status == PSA_SUCCESS )
*mac_length = operation->mac_size;
else
memset( mac, '!', mac_size );
}
else
psa_mac_abort( operation );
return( status );
}
psa_status_t psa_mac_verify_finish( psa_mac_operation_t *operation,
const uint8_t *mac,
size_t mac_length )
{
uint8_t actual_mac[PSA_MAC_MAX_SIZE];
psa_status_t status;
if( operation->is_sign )
{
status = PSA_ERROR_BAD_STATE;
goto cleanup;
}
if( operation->mac_size != mac_length )
{
status = PSA_ERROR_INVALID_SIGNATURE;
goto cleanup;
}
status = psa_mac_finish_internal( operation,
actual_mac, sizeof( actual_mac ) );
if( safer_memcmp( mac, actual_mac, mac_length ) != 0 )
status = PSA_ERROR_INVALID_SIGNATURE;
cleanup:
if( status == PSA_SUCCESS )
status = psa_mac_abort( operation );
else
psa_mac_abort( operation );
mbedtls_zeroize( actual_mac, sizeof( actual_mac ) );
return( status );
}
/****************************************************************/
/* Asymmetric cryptography */
/****************************************************************/
#if defined(MBEDTLS_RSA_C)
/* 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
#if defined(MBEDTLS_PKCS1_V15)
/* For PKCS#1 v1.5 signature, if using a hash, the hash length
* must be correct. */
if( PSA_ALG_IS_RSA_PKCS1V15_SIGN( alg ) &&
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 );
}
#endif /* MBEDTLS_PKCS1_V15 */
#if defined(MBEDTLS_PKCS1_V21)
/* PSS requires a hash internally. */
if( PSA_ALG_IS_RSA_PSS( alg ) )
{
if( md_info == NULL )
return( PSA_ERROR_NOT_SUPPORTED );
}
#endif /* MBEDTLS_PKCS1_V21 */
return( PSA_SUCCESS );
}
static psa_status_t psa_rsa_sign( mbedtls_rsa_context *rsa,
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;
int ret;
mbedtls_md_type_t md_alg;
status = psa_rsa_decode_md_type( alg, hash_length, &md_alg );
if( status != PSA_SUCCESS )
return( status );
if( signature_size < mbedtls_rsa_get_len( rsa ) )
return( PSA_ERROR_BUFFER_TOO_SMALL );
#if defined(MBEDTLS_PKCS1_V15)
if( PSA_ALG_IS_RSA_PKCS1V15_SIGN( alg ) )
{
mbedtls_rsa_set_padding( rsa, MBEDTLS_RSA_PKCS_V15,
MBEDTLS_MD_NONE );
ret = mbedtls_rsa_pkcs1_sign( rsa,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg,
MBEDTLS_RSA_PRIVATE,
md_alg,
(unsigned int) hash_length,
hash,
signature );
}
else
#endif /* MBEDTLS_PKCS1_V15 */
#if defined(MBEDTLS_PKCS1_V21)
if( PSA_ALG_IS_RSA_PSS( alg ) )
{
mbedtls_rsa_set_padding( rsa, MBEDTLS_RSA_PKCS_V21, md_alg );
ret = mbedtls_rsa_rsassa_pss_sign( rsa,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg,
MBEDTLS_RSA_PRIVATE,
MBEDTLS_MD_NONE,
(unsigned int) hash_length,
hash,
signature );
}
else
#endif /* MBEDTLS_PKCS1_V21 */
{
return( PSA_ERROR_INVALID_ARGUMENT );
}
if( ret == 0 )
*signature_length = mbedtls_rsa_get_len( rsa );
return( mbedtls_to_psa_error( ret ) );
}
static psa_status_t psa_rsa_verify( mbedtls_rsa_context *rsa,
psa_algorithm_t alg,
const uint8_t *hash,
size_t hash_length,
const uint8_t *signature,
size_t signature_length )
{
psa_status_t status;
int ret;
mbedtls_md_type_t md_alg;
status = psa_rsa_decode_md_type( alg, hash_length, &md_alg );
if( status != PSA_SUCCESS )
return( status );
if( signature_length < mbedtls_rsa_get_len( rsa ) )
return( PSA_ERROR_BUFFER_TOO_SMALL );
#if defined(MBEDTLS_PKCS1_V15)
if( PSA_ALG_IS_RSA_PKCS1V15_SIGN( alg ) )
{
mbedtls_rsa_set_padding( rsa, MBEDTLS_RSA_PKCS_V15,
MBEDTLS_MD_NONE );
ret = mbedtls_rsa_pkcs1_verify( rsa,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg,
MBEDTLS_RSA_PUBLIC,
md_alg,
(unsigned int) hash_length,
hash,
signature );
}
else
#endif /* MBEDTLS_PKCS1_V15 */
#if defined(MBEDTLS_PKCS1_V21)
if( PSA_ALG_IS_RSA_PSS( alg ) )
{
mbedtls_rsa_set_padding( rsa, MBEDTLS_RSA_PKCS_V21, md_alg );
ret = mbedtls_rsa_rsassa_pss_verify( rsa,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg,
MBEDTLS_RSA_PUBLIC,
MBEDTLS_MD_NONE,
(unsigned int) hash_length,
hash,
signature );
}
else
#endif /* MBEDTLS_PKCS1_V21 */
{
return( PSA_ERROR_INVALID_ARGUMENT );
}
/* 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. */
if( ret == MBEDTLS_ERR_RSA_INVALID_PADDING )
return( PSA_ERROR_INVALID_SIGNATURE );
return( mbedtls_to_psa_error( ret ) );
}
#endif /* MBEDTLS_RSA_C */
#if defined(MBEDTLS_ECDSA_C)
/* `ecp` cannot be const because `ecp->grp` needs to be non-const
* for mbedtls_ecdsa_sign() and mbedtls_ecdsa_sign_det()
* (even though these functions don't modify it). */
static psa_status_t psa_ecdsa_sign( mbedtls_ecp_keypair *ecp,
psa_algorithm_t alg,
const uint8_t *hash,
size_t hash_length,
uint8_t *signature,
size_t signature_size,
size_t *signature_length )
{
int ret;
mbedtls_mpi r, s;
size_t 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_DSA_IS_DETERMINISTIC( 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 );
mbedtls_md_type_t md_alg = mbedtls_md_get_type( md_info );
MBEDTLS_MPI_CHK( mbedtls_ecdsa_sign_det( &ecp->grp, &r, &s, &ecp->d,
hash, hash_length,
md_alg ) );
}
else
{
MBEDTLS_MPI_CHK( mbedtls_ecdsa_sign( &ecp->grp, &r, &s, &ecp->d,
hash, hash_length,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg ) );
}
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;
return( mbedtls_to_psa_error( ret ) );
}
static psa_status_t psa_ecdsa_verify( mbedtls_ecp_keypair *ecp,
const uint8_t *hash,
size_t hash_length,
const uint8_t *signature,
size_t signature_length )
{
int ret;
mbedtls_mpi r, s;
size_t curve_bytes = PSA_BITS_TO_BYTES( ecp->grp.pbits );
mbedtls_mpi_init( &r );
mbedtls_mpi_init( &s );
if( signature_length != 2 * curve_bytes )
return( PSA_ERROR_INVALID_SIGNATURE );
MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &r,
signature,
curve_bytes ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &s,
signature + curve_bytes,
curve_bytes ) );
ret = mbedtls_ecdsa_verify( &ecp->grp, hash, hash_length,
&ecp->Q, &r, &s );
cleanup:
mbedtls_mpi_free( &r );
mbedtls_mpi_free( &s );
return( mbedtls_to_psa_error( ret ) );
}
#endif /* MBEDTLS_ECDSA_C */
psa_status_t psa_asymmetric_sign( psa_key_slot_t key,
psa_algorithm_t alg,
const uint8_t *hash,
size_t hash_length,
uint8_t *signature,
size_t signature_size,
size_t *signature_length )
{
key_slot_t *slot;
psa_status_t status;
*signature_length = signature_size;
status = psa_get_key_from_slot( key, &slot, PSA_KEY_USAGE_SIGN, alg );
if( status != PSA_SUCCESS )
goto exit;
if( ! PSA_KEY_TYPE_IS_KEYPAIR( slot->type ) )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
#if defined(MBEDTLS_RSA_C)
if( slot->type == PSA_KEY_TYPE_RSA_KEYPAIR )
{
status = psa_rsa_sign( slot->data.rsa,
alg,
hash, hash_length,
signature, signature_size,
signature_length );
}
else
#endif /* defined(MBEDTLS_RSA_C) */
#if defined(MBEDTLS_ECP_C)
if( PSA_KEY_TYPE_IS_ECC( slot->type ) )
{
#if defined(MBEDTLS_ECDSA_C)
if( PSA_ALG_IS_ECDSA( alg ) )
status = psa_ecdsa_sign( slot->data.ecp,
alg,
hash, hash_length,
signature, signature_size,
signature_length );
else
#endif /* defined(MBEDTLS_ECDSA_C) */
{
status = PSA_ERROR_INVALID_ARGUMENT;
}
}
else
#endif /* defined(MBEDTLS_ECP_C) */
{
status = PSA_ERROR_NOT_SUPPORTED;
}
exit:
/* Fill the unused part of the output buffer (the whole buffer on error,
* the trailing part on success) with something that isn't a valid mac
* (barring an attack on the mac and deliberately-crafted input),
* in case the caller doesn't check the return status properly. */
if( status == PSA_SUCCESS )
memset( signature + *signature_length, '!',
signature_size - *signature_length );
else if( signature_size != 0 )
memset( signature, '!', signature_size );
/* If signature_size is 0 then we have nothing to do. We must not call
* memset because signature may be NULL in this case. */
return( status );
}
psa_status_t psa_asymmetric_verify( psa_key_slot_t key,
psa_algorithm_t alg,
const uint8_t *hash,
size_t hash_length,
const uint8_t *signature,
size_t signature_length )
{
key_slot_t *slot;
psa_status_t status;
status = psa_get_key_from_slot( key, &slot, PSA_KEY_USAGE_VERIFY, alg );
if( status != PSA_SUCCESS )
return( status );
#if defined(MBEDTLS_RSA_C)
if( PSA_KEY_TYPE_IS_RSA( slot->type ) )
{
return( psa_rsa_verify( slot->data.rsa,
alg,
hash, hash_length,
signature, signature_length ) );
}
else
#endif /* defined(MBEDTLS_RSA_C) */
#if defined(MBEDTLS_ECP_C)
if( PSA_KEY_TYPE_IS_ECC( slot->type ) )
{
#if defined(MBEDTLS_ECDSA_C)
if( PSA_ALG_IS_ECDSA( alg ) )
return( psa_ecdsa_verify( slot->data.ecp,
hash, hash_length,
signature, signature_length ) );
else
#endif /* defined(MBEDTLS_ECDSA_C) */
{
return( PSA_ERROR_INVALID_ARGUMENT );
}
}
else
#endif /* defined(MBEDTLS_ECP_C) */
{
return( PSA_ERROR_NOT_SUPPORTED );
}
}
#if defined(MBEDTLS_RSA_C) && defined(MBEDTLS_PKCS1_V21)
static void psa_rsa_oaep_set_padding_mode( psa_algorithm_t alg,
mbedtls_rsa_context *rsa )
{
psa_algorithm_t hash_alg = PSA_ALG_RSA_OAEP_GET_HASH( alg );
const mbedtls_md_info_t *md_info = mbedtls_md_info_from_psa( hash_alg );
mbedtls_md_type_t md_alg = mbedtls_md_get_type( md_info );
mbedtls_rsa_set_padding( rsa, MBEDTLS_RSA_PKCS_V21, md_alg );
}
#endif /* defined(MBEDTLS_RSA_C) && defined(MBEDTLS_PKCS1_V21) */
psa_status_t psa_asymmetric_encrypt( psa_key_slot_t key,
psa_algorithm_t alg,
const uint8_t *input,
size_t input_length,
const uint8_t *salt,
size_t salt_length,
uint8_t *output,
size_t output_size,
size_t *output_length )
{
key_slot_t *slot;
psa_status_t status;
(void) input;
(void) input_length;
(void) salt;
(void) output;
(void) output_size;
*output_length = 0;
if( ! PSA_ALG_IS_RSA_OAEP( alg ) && salt_length != 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
status = psa_get_key_from_slot( key, &slot, PSA_KEY_USAGE_ENCRYPT, alg );
if( status != PSA_SUCCESS )
return( status );
if( ! ( PSA_KEY_TYPE_IS_PUBLIC_KEY( slot->type ) ||
PSA_KEY_TYPE_IS_KEYPAIR( slot->type ) ) )
return( PSA_ERROR_INVALID_ARGUMENT );
#if defined(MBEDTLS_RSA_C)
if( PSA_KEY_TYPE_IS_RSA( slot->type ) )
{
mbedtls_rsa_context *rsa = slot->data.rsa;
int ret;
if( output_size < mbedtls_rsa_get_len( rsa ) )
return( PSA_ERROR_INVALID_ARGUMENT );
#if defined(MBEDTLS_PKCS1_V15)
if( alg == PSA_ALG_RSA_PKCS1V15_CRYPT )
{
ret = mbedtls_rsa_pkcs1_encrypt( rsa,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg,
MBEDTLS_RSA_PUBLIC,
input_length,
input,
output );
}
else
#endif /* MBEDTLS_PKCS1_V15 */
#if defined(MBEDTLS_PKCS1_V21)
if( PSA_ALG_IS_RSA_OAEP( alg ) )
{
psa_rsa_oaep_set_padding_mode( alg, rsa );
ret = mbedtls_rsa_rsaes_oaep_encrypt( rsa,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg,
MBEDTLS_RSA_PUBLIC,
salt, salt_length,
input_length,
input,
output );
}
else
#endif /* MBEDTLS_PKCS1_V21 */
{
return( PSA_ERROR_INVALID_ARGUMENT );
}
if( ret == 0 )
*output_length = mbedtls_rsa_get_len( rsa );
return( mbedtls_to_psa_error( ret ) );
}
else
#endif /* defined(MBEDTLS_RSA_C) */
{
return( PSA_ERROR_NOT_SUPPORTED );
}
}
psa_status_t psa_asymmetric_decrypt( psa_key_slot_t key,
psa_algorithm_t alg,
const uint8_t *input,
size_t input_length,
const uint8_t *salt,
size_t salt_length,
uint8_t *output,
size_t output_size,
size_t *output_length )
{
key_slot_t *slot;
psa_status_t status;
(void) input;
(void) input_length;
(void) salt;
(void) output;
(void) output_size;
*output_length = 0;
if( ! PSA_ALG_IS_RSA_OAEP( alg ) && salt_length != 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
status = psa_get_key_from_slot( key, &slot, PSA_KEY_USAGE_DECRYPT, alg );
if( status != PSA_SUCCESS )
return( status );
if( ! PSA_KEY_TYPE_IS_KEYPAIR( slot->type ) )
return( PSA_ERROR_INVALID_ARGUMENT );
#if defined(MBEDTLS_RSA_C)
if( slot->type == PSA_KEY_TYPE_RSA_KEYPAIR )
{
mbedtls_rsa_context *rsa = slot->data.rsa;
int ret;
if( input_length != mbedtls_rsa_get_len( rsa ) )
return( PSA_ERROR_INVALID_ARGUMENT );
#if defined(MBEDTLS_PKCS1_V15)
if( alg == PSA_ALG_RSA_PKCS1V15_CRYPT )
{
ret = mbedtls_rsa_pkcs1_decrypt( rsa,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg,
MBEDTLS_RSA_PRIVATE,
output_length,
input,
output,
output_size );
}
else
#endif /* MBEDTLS_PKCS1_V15 */
#if defined(MBEDTLS_PKCS1_V21)
if( PSA_ALG_IS_RSA_OAEP( alg ) )
{
psa_rsa_oaep_set_padding_mode( alg, rsa );
ret = mbedtls_rsa_rsaes_oaep_decrypt( rsa,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg,
MBEDTLS_RSA_PRIVATE,
salt, salt_length,
output_length,
input,
output,
output_size );
}
else
#endif /* MBEDTLS_PKCS1_V21 */
{
return( PSA_ERROR_INVALID_ARGUMENT );
}
return( mbedtls_to_psa_error( ret ) );
}
else
#endif /* defined(MBEDTLS_RSA_C) */
{
return( PSA_ERROR_NOT_SUPPORTED );
}
}
/****************************************************************/
/* Symmetric cryptography */
/****************************************************************/
/* Initialize the cipher operation structure. Once this function has been
* called, psa_cipher_abort can run and will do the right thing. */
static psa_status_t psa_cipher_init( psa_cipher_operation_t *operation,
psa_algorithm_t alg )
{
if( ! PSA_ALG_IS_CIPHER( alg ) )
{
memset( operation, 0, sizeof( *operation ) );
return( PSA_ERROR_INVALID_ARGUMENT );
}
operation->alg = alg;
operation->key_set = 0;
operation->iv_set = 0;
operation->iv_required = 1;
operation->iv_size = 0;
operation->block_size = 0;
mbedtls_cipher_init( &operation->ctx.cipher );
return( PSA_SUCCESS );
}
static psa_status_t psa_cipher_setup( psa_cipher_operation_t *operation,
psa_key_slot_t key,
psa_algorithm_t alg,
mbedtls_operation_t cipher_operation )
{
int ret = MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
psa_status_t status;
key_slot_t *slot;
size_t key_bits;
const mbedtls_cipher_info_t *cipher_info = NULL;
psa_key_usage_t usage = ( cipher_operation == MBEDTLS_ENCRYPT ?
PSA_KEY_USAGE_ENCRYPT :
PSA_KEY_USAGE_DECRYPT );
status = psa_cipher_init( operation, alg );
if( status != PSA_SUCCESS )
return( status );
status = psa_get_key_from_slot( key, &slot, usage, alg);
if( status != PSA_SUCCESS )
return( status );
key_bits = psa_get_key_bits( slot );
cipher_info = mbedtls_cipher_info_from_psa( alg, slot->type, key_bits, NULL );
if( cipher_info == NULL )
return( PSA_ERROR_NOT_SUPPORTED );
ret = mbedtls_cipher_setup( &operation->ctx.cipher, cipher_info );
if( ret != 0 )
{
psa_cipher_abort( operation );
return( mbedtls_to_psa_error( ret ) );
}
#if defined(MBEDTLS_DES_C)
if( slot->type == PSA_KEY_TYPE_DES && key_bits == 128 )
{
/* Two-key Triple-DES is 3-key Triple-DES with K1=K3 */
unsigned char keys[24];
memcpy( keys, slot->data.raw.data, 16 );
memcpy( keys + 16, slot->data.raw.data, 8 );
ret = mbedtls_cipher_setkey( &operation->ctx.cipher,
keys,
192, cipher_operation );
}
else
#endif
{
ret = mbedtls_cipher_setkey( &operation->ctx.cipher,
slot->data.raw.data,
(int) key_bits, cipher_operation );
}
if( ret != 0 )
{
psa_cipher_abort( operation );
return( mbedtls_to_psa_error( ret ) );
}
#if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
switch( alg )
{
case PSA_ALG_CBC_NO_PADDING:
ret = mbedtls_cipher_set_padding_mode( &operation->ctx.cipher,
MBEDTLS_PADDING_NONE );
break;
case PSA_ALG_CBC_PKCS7:
ret = mbedtls_cipher_set_padding_mode( &operation->ctx.cipher,
MBEDTLS_PADDING_PKCS7 );
break;
default:
/* The algorithm doesn't involve padding. */
ret = 0;
break;
}
if( ret != 0 )
{
psa_cipher_abort( operation );
return( mbedtls_to_psa_error( ret ) );
}
#endif //MBEDTLS_CIPHER_MODE_WITH_PADDING
operation->key_set = 1;
operation->block_size = ( PSA_ALG_IS_STREAM_CIPHER( alg ) ? 1 :
PSA_BLOCK_CIPHER_BLOCK_SIZE( slot->type ) );
if( alg & PSA_ALG_CIPHER_FROM_BLOCK_FLAG )
{
operation->iv_size = PSA_BLOCK_CIPHER_BLOCK_SIZE( slot->type );
}
return( PSA_SUCCESS );
}
psa_status_t psa_cipher_encrypt_setup( psa_cipher_operation_t *operation,
psa_key_slot_t key,
psa_algorithm_t alg )
{
return( psa_cipher_setup( operation, key, alg, MBEDTLS_ENCRYPT ) );
}
psa_status_t psa_cipher_decrypt_setup( psa_cipher_operation_t *operation,
psa_key_slot_t key,
psa_algorithm_t alg )
{
return( psa_cipher_setup( operation, key, alg, MBEDTLS_DECRYPT ) );
}
psa_status_t psa_cipher_generate_iv( psa_cipher_operation_t *operation,
unsigned char *iv,
size_t iv_size,
size_t *iv_length )
{
psa_status_t status;
int ret;
if( operation->iv_set || ! operation->iv_required )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
if( iv_size < operation->iv_size )
{
status = PSA_ERROR_BUFFER_TOO_SMALL;
goto exit;
}
ret = mbedtls_ctr_drbg_random( &global_data.ctr_drbg,
iv, operation->iv_size );
if( ret != 0 )
{
status = mbedtls_to_psa_error( ret );
goto exit;
}
*iv_length = operation->iv_size;
status = psa_cipher_set_iv( operation, iv, *iv_length );
exit:
if( status != PSA_SUCCESS )
psa_cipher_abort( operation );
return( status );
}
psa_status_t psa_cipher_set_iv( psa_cipher_operation_t *operation,
const unsigned char *iv,
size_t iv_length )
{
psa_status_t status;
int ret;
if( operation->iv_set || ! operation->iv_required )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
if( iv_length != operation->iv_size )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
ret = mbedtls_cipher_set_iv( &operation->ctx.cipher, iv, iv_length );
status = mbedtls_to_psa_error( ret );
exit:
if( status == PSA_SUCCESS )
operation->iv_set = 1;
else
psa_cipher_abort( operation );
return( status );
}
psa_status_t psa_cipher_update( psa_cipher_operation_t *operation,
const uint8_t *input,
size_t input_length,
unsigned char *output,
size_t output_size,
size_t *output_length )
{
psa_status_t status;
int ret;
size_t expected_output_size;
if( ! PSA_ALG_IS_STREAM_CIPHER( operation->alg ) )
{
/* Take the unprocessed partial block left over from previous
* update calls, if any, plus the input to this call. Remove
* the last partial block, if any. You get the data that will be
* output in this call. */
expected_output_size =
( operation->ctx.cipher.unprocessed_len + input_length )
/ operation->block_size * operation->block_size;
}
else
{
expected_output_size = input_length;
}
if( output_size < expected_output_size )
{
status = PSA_ERROR_BUFFER_TOO_SMALL;
goto exit;
}
ret = mbedtls_cipher_update( &operation->ctx.cipher, input,
input_length, output, output_length );
status = mbedtls_to_psa_error( ret );
exit:
if( status != PSA_SUCCESS )
psa_cipher_abort( operation );
return( status );
}
psa_status_t psa_cipher_finish( psa_cipher_operation_t *operation,
uint8_t *output,
size_t output_size,
size_t *output_length )
{
psa_status_t status = PSA_ERROR_UNKNOWN_ERROR;
int cipher_ret = MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
uint8_t temp_output_buffer[MBEDTLS_MAX_BLOCK_LENGTH];
if( ! operation->key_set )
{
status = PSA_ERROR_BAD_STATE;
goto error;
}
if( operation->iv_required && ! operation->iv_set )
{
status = PSA_ERROR_BAD_STATE;
goto error;
}
if( operation->ctx.cipher.operation == MBEDTLS_ENCRYPT &&
operation->alg == PSA_ALG_CBC_NO_PADDING &&
operation->ctx.cipher.unprocessed_len != 0 )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto error;
}
cipher_ret = mbedtls_cipher_finish( &operation->ctx.cipher,
temp_output_buffer,
output_length );
if( cipher_ret != 0 )
{
status = mbedtls_to_psa_error( cipher_ret );
goto error;
}
if( *output_length == 0 )
; /* Nothing to copy. Note that output may be NULL in this case. */
else if( output_size >= *output_length )
memcpy( output, temp_output_buffer, *output_length );
else
{
status = PSA_ERROR_BUFFER_TOO_SMALL;
goto error;
}
mbedtls_zeroize( temp_output_buffer, sizeof( temp_output_buffer ) );
status = psa_cipher_abort( operation );
return( status );
error:
*output_length = 0;
mbedtls_zeroize( temp_output_buffer, sizeof( temp_output_buffer ) );
(void) psa_cipher_abort( operation );
return( status );
}
psa_status_t psa_cipher_abort( psa_cipher_operation_t *operation )
{
if( operation->alg == 0 )
{
/* The object has (apparently) been initialized but it is not
* in use. It's ok to call abort on such an object, and there's
* nothing to do. */
return( PSA_SUCCESS );
}
/* Sanity check (shouldn't happen: operation->alg should
* always have been initialized to a valid value). */
if( ! PSA_ALG_IS_CIPHER( operation->alg ) )
return( PSA_ERROR_BAD_STATE );
mbedtls_cipher_free( &operation->ctx.cipher );
operation->alg = 0;
operation->key_set = 0;
operation->iv_set = 0;
operation->iv_size = 0;
operation->block_size = 0;
operation->iv_required = 0;
return( PSA_SUCCESS );
}
/****************************************************************/
/* Key Policy */
/****************************************************************/
#if !defined(MBEDTLS_PSA_CRYPTO_SPM)
void psa_key_policy_init( psa_key_policy_t *policy )
{
memset( policy, 0, sizeof( *policy ) );
}
void psa_key_policy_set_usage( psa_key_policy_t *policy,
psa_key_usage_t usage,
psa_algorithm_t alg )
{
policy->usage = usage;
policy->alg = alg;
}
psa_key_usage_t psa_key_policy_get_usage( const psa_key_policy_t *policy )
{
return( policy->usage );
}
psa_algorithm_t psa_key_policy_get_algorithm( const psa_key_policy_t *policy )
{
return( policy->alg );
}
#endif /* !defined(MBEDTLS_PSA_CRYPTO_SPM) */
psa_status_t psa_set_key_policy( psa_key_slot_t key,
const psa_key_policy_t *policy )
{
key_slot_t *slot;
psa_status_t status;
if( policy == NULL )
return( PSA_ERROR_INVALID_ARGUMENT );
status = psa_get_empty_key_slot( key, &slot );
if( status != PSA_SUCCESS )
return( status );
if( ( policy->usage & ~( PSA_KEY_USAGE_EXPORT |
PSA_KEY_USAGE_ENCRYPT |
PSA_KEY_USAGE_DECRYPT |
PSA_KEY_USAGE_SIGN |
PSA_KEY_USAGE_VERIFY |
PSA_KEY_USAGE_DERIVE ) ) != 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
slot->policy = *policy;
return( PSA_SUCCESS );
}
psa_status_t psa_get_key_policy( psa_key_slot_t key,
psa_key_policy_t *policy )
{
key_slot_t *slot;
psa_status_t status;
if( policy == NULL )
return( PSA_ERROR_INVALID_ARGUMENT );
status = psa_get_key_slot( key, &slot );
if( status != PSA_SUCCESS )
return( status );
*policy = slot->policy;
return( PSA_SUCCESS );
}
/****************************************************************/
/* Key Lifetime */
/****************************************************************/
psa_status_t psa_get_key_lifetime( psa_key_slot_t key,
psa_key_lifetime_t *lifetime )
{
key_slot_t *slot;
psa_status_t status;
status = psa_get_key_slot( key, &slot );
if( status != PSA_SUCCESS )
return( status );
*lifetime = slot->lifetime;
return( PSA_SUCCESS );
}
psa_status_t psa_set_key_lifetime( psa_key_slot_t key,
psa_key_lifetime_t lifetime )
{
key_slot_t *slot;
psa_status_t status;
if( lifetime != PSA_KEY_LIFETIME_VOLATILE &&
lifetime != PSA_KEY_LIFETIME_PERSISTENT &&
lifetime != PSA_KEY_LIFETIME_WRITE_ONCE)
return( PSA_ERROR_INVALID_ARGUMENT );
status = psa_get_empty_key_slot( key, &slot );
if( status != PSA_SUCCESS )
return( status );
if( lifetime != PSA_KEY_LIFETIME_VOLATILE )
return( PSA_ERROR_NOT_SUPPORTED );
slot->lifetime = lifetime;
return( PSA_SUCCESS );
}
/****************************************************************/
/* AEAD */
/****************************************************************/
typedef struct
{
key_slot_t *slot;
const mbedtls_cipher_info_t *cipher_info;
union
{
#if defined(MBEDTLS_CCM_C)
mbedtls_ccm_context ccm;
#endif /* MBEDTLS_CCM_C */
#if defined(MBEDTLS_GCM_C)
mbedtls_gcm_context gcm;
#endif /* MBEDTLS_GCM_C */
} ctx;
psa_algorithm_t core_alg;
uint8_t full_tag_length;
uint8_t tag_length;
} aead_operation_t;
static void psa_aead_abort( aead_operation_t *operation )
{
switch( operation->core_alg )
{
#if defined(MBEDTLS_CCM_C)
case PSA_ALG_CCM:
mbedtls_ccm_free( &operation->ctx.ccm );
break;
#endif /* MBEDTLS_CCM_C */
#if defined(MBEDTLS_CCM_C)
case PSA_ALG_GCM:
mbedtls_gcm_free( &operation->ctx.gcm );
break;
#endif /* MBEDTLS_GCM_C */
}
}
static psa_status_t psa_aead_setup( aead_operation_t *operation,
psa_key_slot_t key,
psa_key_usage_t usage,
psa_algorithm_t alg )
{
psa_status_t status;
size_t key_bits;
mbedtls_cipher_id_t cipher_id;
status = psa_get_key_from_slot( key, &operation->slot, usage, alg );
if( status != PSA_SUCCESS )
return( status );
key_bits = psa_get_key_bits( operation->slot );
operation->cipher_info =
mbedtls_cipher_info_from_psa( alg, operation->slot->type, key_bits,
&cipher_id );
if( operation->cipher_info == NULL )
return( PSA_ERROR_NOT_SUPPORTED );
switch( PSA_ALG_AEAD_WITH_TAG_LENGTH( alg, 0 ) )
{
#if defined(MBEDTLS_CCM_C)
case PSA_ALG_AEAD_WITH_TAG_LENGTH( PSA_ALG_CCM, 0 ):
operation->core_alg = PSA_ALG_CCM;
operation->full_tag_length = 16;
if( PSA_BLOCK_CIPHER_BLOCK_SIZE( operation->slot->type ) != 16 )
return( PSA_ERROR_INVALID_ARGUMENT );
mbedtls_ccm_init( &operation->ctx.ccm );
status = mbedtls_to_psa_error(
mbedtls_ccm_setkey( &operation->ctx.ccm, cipher_id,
operation->slot->data.raw.data,
(unsigned int) key_bits ) );
if( status != 0 )
goto cleanup;
break;
#endif /* MBEDTLS_CCM_C */
#if defined(MBEDTLS_GCM_C)
case PSA_ALG_AEAD_WITH_TAG_LENGTH( PSA_ALG_GCM, 0 ):
operation->core_alg = PSA_ALG_GCM;
operation->full_tag_length = 16;
if( PSA_BLOCK_CIPHER_BLOCK_SIZE( operation->slot->type ) != 16 )
return( PSA_ERROR_INVALID_ARGUMENT );
mbedtls_gcm_init( &operation->ctx.gcm );
status = mbedtls_to_psa_error(
mbedtls_gcm_setkey( &operation->ctx.gcm, cipher_id,
operation->slot->data.raw.data,
(unsigned int) key_bits ) );
break;
#endif /* MBEDTLS_GCM_C */
default:
return( PSA_ERROR_NOT_SUPPORTED );
}
if( PSA_AEAD_TAG_LENGTH( alg ) > operation->full_tag_length )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto cleanup;
}
operation->tag_length = PSA_AEAD_TAG_LENGTH( alg );
/* CCM allows the following tag lengths: 4, 6, 8, 10, 12, 14, 16.
* GCM allows the following tag lengths: 4, 8, 12, 13, 14, 15, 16.
* In both cases, mbedtls_xxx will validate the tag length below. */
return( PSA_SUCCESS );
cleanup:
psa_aead_abort( operation );
return( status );
}
psa_status_t psa_aead_encrypt( psa_key_slot_t key,
psa_algorithm_t alg,
const uint8_t *nonce,
size_t nonce_length,
const uint8_t *additional_data,
size_t additional_data_length,
const uint8_t *plaintext,
size_t plaintext_length,
uint8_t *ciphertext,
size_t ciphertext_size,
size_t *ciphertext_length )
{
psa_status_t status;
aead_operation_t operation;
uint8_t *tag;
*ciphertext_length = 0;
status = psa_aead_setup( &operation, key, PSA_KEY_USAGE_ENCRYPT, alg );
if( status != PSA_SUCCESS )
return( status );
/* For all currently supported modes, the tag is at the end of the
* ciphertext. */
if( ciphertext_size < ( plaintext_length + operation.tag_length ) )
{
status = PSA_ERROR_BUFFER_TOO_SMALL;
goto exit;
}
tag = ciphertext + plaintext_length;
if( operation.core_alg == PSA_ALG_GCM )
{
status = mbedtls_to_psa_error(
mbedtls_gcm_crypt_and_tag( &operation.ctx.gcm,
MBEDTLS_GCM_ENCRYPT,
plaintext_length,
nonce, nonce_length,
additional_data, additional_data_length,
plaintext, ciphertext,
operation.tag_length, tag ) );
}
else if( operation.core_alg == PSA_ALG_CCM )
{
status = mbedtls_to_psa_error(
mbedtls_ccm_encrypt_and_tag( &operation.ctx.ccm,
plaintext_length,
nonce, nonce_length,
additional_data,
additional_data_length,
plaintext, ciphertext,
tag, operation.tag_length ) );
}
else
{
return( PSA_ERROR_NOT_SUPPORTED );
}
if( status != PSA_SUCCESS && ciphertext_size != 0 )
memset( ciphertext, 0, ciphertext_size );
exit:
psa_aead_abort( &operation );
if( status == PSA_SUCCESS )
*ciphertext_length = plaintext_length + operation.tag_length;
return( status );
}
/* Locate the tag in a ciphertext buffer containing the encrypted data
* followed by the tag. Return the length of the part preceding the tag in
* *plaintext_length. This is the size of the plaintext in modes where
* the encrypted data has the same size as the plaintext, such as
* CCM and GCM. */
static psa_status_t psa_aead_unpadded_locate_tag( size_t tag_length,
const uint8_t *ciphertext,
size_t ciphertext_length,
size_t plaintext_size,
const uint8_t **p_tag )
{
size_t payload_length;
if( tag_length > ciphertext_length )
return( PSA_ERROR_INVALID_ARGUMENT );
payload_length = ciphertext_length - tag_length;
if( payload_length > plaintext_size )
return( PSA_ERROR_BUFFER_TOO_SMALL );
*p_tag = ciphertext + payload_length;
return( PSA_SUCCESS );
}
psa_status_t psa_aead_decrypt( psa_key_slot_t key,
psa_algorithm_t alg,
const uint8_t *nonce,
size_t nonce_length,
const uint8_t *additional_data,
size_t additional_data_length,
const uint8_t *ciphertext,
size_t ciphertext_length,
uint8_t *plaintext,
size_t plaintext_size,
size_t *plaintext_length )
{
psa_status_t status;
aead_operation_t operation;
const uint8_t *tag = NULL;
*plaintext_length = 0;
status = psa_aead_setup( &operation, key, PSA_KEY_USAGE_DECRYPT, alg );
if( status != PSA_SUCCESS )
return( status );
if( operation.core_alg == PSA_ALG_GCM )
{
status = psa_aead_unpadded_locate_tag( operation.tag_length,
ciphertext, ciphertext_length,
plaintext_size, &tag );
if( status != PSA_SUCCESS )
goto exit;
status = mbedtls_to_psa_error(
mbedtls_gcm_auth_decrypt( &operation.ctx.gcm,
ciphertext_length - operation.tag_length,
nonce, nonce_length,
additional_data,
additional_data_length,
tag, operation.tag_length,
ciphertext, plaintext ) );
}
else if( operation.core_alg == PSA_ALG_CCM )
{
status = psa_aead_unpadded_locate_tag( operation.tag_length,
ciphertext, ciphertext_length,
plaintext_size, &tag );
if( status != PSA_SUCCESS )
goto exit;
status = mbedtls_to_psa_error(
mbedtls_ccm_auth_decrypt( &operation.ctx.ccm,
ciphertext_length - operation.tag_length,
nonce, nonce_length,
additional_data,
additional_data_length,
ciphertext, plaintext,
tag, operation.tag_length ) );
}
else
{
return( PSA_ERROR_NOT_SUPPORTED );
}
if( status != PSA_SUCCESS && plaintext_size != 0 )
memset( plaintext, 0, plaintext_size );
exit:
psa_aead_abort( &operation );
if( status == PSA_SUCCESS )
*plaintext_length = ciphertext_length - operation.tag_length;
return( status );
}
/****************************************************************/
/* Generators */
/****************************************************************/
psa_status_t psa_generator_abort( psa_crypto_generator_t *generator )
{
psa_status_t status = PSA_SUCCESS;
if( generator->alg == 0 )
{
/* The object has (apparently) been initialized but it is not
* in use. It's ok to call abort on such an object, and there's
* nothing to do. */
}
else
#if defined(MBEDTLS_MD_C)
if( PSA_ALG_IS_HKDF( generator->alg ) )
{
mbedtls_free( generator->ctx.hkdf.info );
status = psa_hmac_abort_internal( &generator->ctx.hkdf.hmac );
}
else
#endif /* MBEDTLS_MD_C */
{
status = PSA_ERROR_BAD_STATE;
}
memset( generator, 0, sizeof( *generator ) );
return( status );
}
psa_status_t psa_get_generator_capacity(const psa_crypto_generator_t *generator,
size_t *capacity)
{
*capacity = generator->capacity;
return( PSA_SUCCESS );
}
#if defined(MBEDTLS_MD_C)
/* Read some bytes from an HKDF-based generator. This performs a chunk
* of the expand phase of the HKDF algorithm. */
static psa_status_t psa_generator_hkdf_read( psa_hkdf_generator_t *hkdf,
psa_algorithm_t hash_alg,
uint8_t *output,
size_t output_length )
{
uint8_t hash_length = PSA_HASH_SIZE( hash_alg );
psa_status_t status;
while( output_length != 0 )
{
/* Copy what remains of the current block */
uint8_t n = hash_length - hkdf->offset_in_block;
if( n > output_length )
n = (uint8_t) output_length;
memcpy( output, hkdf->output_block + hkdf->offset_in_block, n );
output += n;
output_length -= n;
hkdf->offset_in_block += n;
if( output_length == 0 )
break;
/* We can't be wanting more output after block 0xff, otherwise
* the capacity check in psa_generator_read() would have
* prevented this call. It could happen only if the generator
* object was corrupted or if this function is called directly
* inside the library. */
if( hkdf->block_number == 0xff )
return( PSA_ERROR_BAD_STATE );
/* We need a new block */
++hkdf->block_number;
hkdf->offset_in_block = 0;
status = psa_hmac_setup_internal( &hkdf->hmac,
hkdf->prk, hash_length,
hash_alg );
if( status != PSA_SUCCESS )
return( status );
if( hkdf->block_number != 1 )
{
status = psa_hash_update( &hkdf->hmac.hash_ctx,
hkdf->output_block,
hash_length );
if( status != PSA_SUCCESS )
return( status );
}
status = psa_hash_update( &hkdf->hmac.hash_ctx,
hkdf->info,
hkdf->info_length );
if( status != PSA_SUCCESS )
return( status );
status = psa_hash_update( &hkdf->hmac.hash_ctx,
&hkdf->block_number, 1 );
if( status != PSA_SUCCESS )
return( status );
status = psa_hmac_finish_internal( &hkdf->hmac,
hkdf->output_block,
sizeof( hkdf->output_block ) );
if( status != PSA_SUCCESS )
return( status );
}
return( PSA_SUCCESS );
}
#endif /* MBEDTLS_MD_C */
psa_status_t psa_generator_read( psa_crypto_generator_t *generator,
uint8_t *output,
size_t output_length )
{
psa_status_t status;
if( output_length > generator->capacity )
{
generator->capacity = 0;
/* Go through the error path to wipe all confidential data now
* that the generator object is useless. */
status = PSA_ERROR_INSUFFICIENT_CAPACITY;
goto exit;
}
if( output_length == 0 &&
generator->capacity == 0 && generator->alg == 0 )
{
/* Edge case: this is a blank or finished generator, and 0
* bytes were requested. The right error in this case could
* be either INSUFFICIENT_CAPACITY or BAD_STATE. Return
* INSUFFICIENT_CAPACITY, which is right for a finished
* generator, for consistency with the case when
* output_length > 0. */
return( PSA_ERROR_INSUFFICIENT_CAPACITY );
}
generator->capacity -= output_length;
#if defined(MBEDTLS_MD_C)
if( PSA_ALG_IS_HKDF( generator->alg ) )
{
psa_algorithm_t hash_alg = PSA_ALG_HKDF_GET_HASH( generator->alg );
status = psa_generator_hkdf_read( &generator->ctx.hkdf, hash_alg,
output, output_length );
}
else
#endif /* MBEDTLS_MD_C */
{
return( PSA_ERROR_BAD_STATE );
}
exit:
if( status != PSA_SUCCESS )
{
psa_generator_abort( generator );
memset( output, '!', output_length );
}
return( status );
}
#if defined(MBEDTLS_DES_C)
static void psa_des_set_key_parity( uint8_t *data, size_t data_size )
{
if( data_size >= 8 )
mbedtls_des_key_set_parity( data );
if( data_size >= 16 )
mbedtls_des_key_set_parity( data + 8 );
if( data_size >= 24 )
mbedtls_des_key_set_parity( data + 16 );
}
#endif /* MBEDTLS_DES_C */
psa_status_t psa_generator_import_key( psa_key_slot_t key,
psa_key_type_t type,
size_t bits,
psa_crypto_generator_t *generator )
{
uint8_t *data = NULL;
size_t bytes = PSA_BITS_TO_BYTES( bits );
psa_status_t status;
if( ! key_type_is_raw_bytes( type ) )
return( PSA_ERROR_INVALID_ARGUMENT );
if( bits % 8 != 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
data = mbedtls_calloc( 1, bytes );
if( data == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
status = psa_generator_read( generator, data, bytes );
if( status != PSA_SUCCESS )
goto exit;
#if defined(MBEDTLS_DES_C)
if( type == PSA_KEY_TYPE_DES )
psa_des_set_key_parity( data, bytes );
#endif /* MBEDTLS_DES_C */
status = psa_import_key( key, type, data, bytes );
exit:
mbedtls_free( data );
return( status );
}
/****************************************************************/
/* Key derivation */
/****************************************************************/
/* Set up an HKDF-based generator. This is exactly the extract phase
* of the HKDF algorithm. */
static psa_status_t psa_generator_hkdf_setup( psa_hkdf_generator_t *hkdf,
key_slot_t *slot,
psa_algorithm_t hash_alg,
const uint8_t *salt,
size_t salt_length,
const uint8_t *label,
size_t label_length )
{
psa_status_t status;
status = psa_hmac_setup_internal( &hkdf->hmac,
salt, salt_length,
PSA_ALG_HMAC_GET_HASH( hash_alg ) );
if( status != PSA_SUCCESS )
return( status );
status = psa_hash_update( &hkdf->hmac.hash_ctx,
slot->data.raw.data,
slot->data.raw.bytes );
if( status != PSA_SUCCESS )
return( status );
status = psa_hmac_finish_internal( &hkdf->hmac,
hkdf->prk,
sizeof( hkdf->prk ) );
if( status != PSA_SUCCESS )
return( status );
hkdf->offset_in_block = PSA_HASH_SIZE( hash_alg );
hkdf->block_number = 0;
hkdf->info_length = label_length;
if( label_length != 0 )
{
hkdf->info = mbedtls_calloc( 1, label_length );
if( hkdf->info == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
memcpy( hkdf->info, label, label_length );
}
return( PSA_SUCCESS );
}
psa_status_t psa_key_derivation( psa_crypto_generator_t *generator,
psa_key_slot_t key,
psa_algorithm_t alg,
const uint8_t *salt,
size_t salt_length,
const uint8_t *label,
size_t label_length,
size_t capacity )
{
key_slot_t *slot;
psa_status_t status;
if( generator->alg != 0 )
return( PSA_ERROR_BAD_STATE );
status = psa_get_key_from_slot( key, &slot, PSA_KEY_USAGE_DERIVE, alg );
if( status != PSA_SUCCESS )
return( status );
if( slot->type != PSA_KEY_TYPE_DERIVE )
return( PSA_ERROR_INVALID_ARGUMENT );
if( ! PSA_ALG_IS_KEY_DERIVATION( alg ) )
return( PSA_ERROR_INVALID_ARGUMENT );
#if defined(MBEDTLS_MD_C)
if( PSA_ALG_IS_HKDF( alg ) )
{
psa_algorithm_t hash_alg = PSA_ALG_HKDF_GET_HASH( alg );
size_t hash_size = PSA_HASH_SIZE( hash_alg );
if( hash_size == 0 )
return( PSA_ERROR_NOT_SUPPORTED );
if( capacity > 255 * hash_size )
return( PSA_ERROR_INVALID_ARGUMENT );
status = psa_generator_hkdf_setup( &generator->ctx.hkdf,
slot,
hash_alg,
salt, salt_length,
label, label_length );
}
else
#endif
{
return( PSA_ERROR_NOT_SUPPORTED );
}
/* Set generator->alg even on failure so that abort knows what to do. */
generator->alg = alg;
if( status == PSA_SUCCESS )
generator->capacity = capacity;
else
psa_generator_abort( generator );
return( status );
}
/****************************************************************/
/* Random generation */
/****************************************************************/
psa_status_t psa_generate_random( uint8_t *output,
size_t output_size )
{
int ret;
GUARD_MODULE_INITIALIZED;
ret = mbedtls_ctr_drbg_random( &global_data.ctr_drbg, output, output_size );
return( mbedtls_to_psa_error( ret ) );
}
psa_status_t psa_generate_key( psa_key_slot_t key,
psa_key_type_t type,
size_t bits,
const void *extra,
size_t extra_size )
{
key_slot_t *slot;
psa_status_t status;
if( extra == NULL && extra_size != 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
status = psa_get_empty_key_slot( key, &slot );
if( status != PSA_SUCCESS )
return( status );
if( key_type_is_raw_bytes( type ) )
{
status = prepare_raw_data_slot( type, bits, &slot->data.raw );
if( status != PSA_SUCCESS )
return( status );
status = psa_generate_random( slot->data.raw.data,
slot->data.raw.bytes );
if( status != PSA_SUCCESS )
{
mbedtls_free( slot->data.raw.data );
return( status );
}
#if defined(MBEDTLS_DES_C)
if( type == PSA_KEY_TYPE_DES )
psa_des_set_key_parity( slot->data.raw.data,
slot->data.raw.bytes );
#endif /* MBEDTLS_DES_C */
}
else
#if defined(MBEDTLS_RSA_C) && defined(MBEDTLS_GENPRIME)
if ( type == PSA_KEY_TYPE_RSA_KEYPAIR )
{
mbedtls_rsa_context *rsa;
int ret;
int exponent = 65537;
if( bits > PSA_VENDOR_RSA_MAX_KEY_BITS )
return( PSA_ERROR_NOT_SUPPORTED );
if( extra != NULL )
{
const psa_generate_key_extra_rsa *p = extra;
if( extra_size != sizeof( *p ) )
return( PSA_ERROR_INVALID_ARGUMENT );
#if INT_MAX < 0xffffffff
/* Check that the uint32_t value passed by the caller fits
* in the range supported by this implementation. */
if( p->e > INT_MAX )
return( PSA_ERROR_NOT_SUPPORTED );
#endif
exponent = p->e;
}
rsa = mbedtls_calloc( 1, sizeof( *rsa ) );
if( rsa == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
mbedtls_rsa_init( rsa, MBEDTLS_RSA_PKCS_V15, MBEDTLS_MD_NONE );
ret = mbedtls_rsa_gen_key( rsa,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg,
(unsigned int) bits,
exponent );
if( ret != 0 )
{
mbedtls_rsa_free( rsa );
mbedtls_free( rsa );
return( mbedtls_to_psa_error( ret ) );
}
slot->data.rsa = rsa;
}
else
#endif /* MBEDTLS_RSA_C && MBEDTLS_GENPRIME */
#if defined(MBEDTLS_ECP_C)
if ( PSA_KEY_TYPE_IS_ECC( type ) && PSA_KEY_TYPE_IS_KEYPAIR( type ) )
{
psa_ecc_curve_t curve = PSA_KEY_TYPE_GET_CURVE( type );
mbedtls_ecp_group_id grp_id = mbedtls_ecc_group_of_psa( curve );
const mbedtls_ecp_curve_info *curve_info =
mbedtls_ecp_curve_info_from_grp_id( grp_id );
mbedtls_ecp_keypair *ecp;
int ret;
if( extra != NULL )
return( PSA_ERROR_NOT_SUPPORTED );
if( grp_id == MBEDTLS_ECP_DP_NONE || curve_info == NULL )
return( PSA_ERROR_NOT_SUPPORTED );
if( curve_info->bit_size != bits )
return( PSA_ERROR_INVALID_ARGUMENT );
ecp = mbedtls_calloc( 1, sizeof( *ecp ) );
if( ecp == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
mbedtls_ecp_keypair_init( ecp );
ret = mbedtls_ecp_gen_key( grp_id, ecp,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg );
if( ret != 0 )
{
mbedtls_ecp_keypair_free( ecp );
mbedtls_free( ecp );
return( mbedtls_to_psa_error( ret ) );
}
slot->data.ecp = ecp;
}
else
#endif /* MBEDTLS_ECP_C */
return( PSA_ERROR_NOT_SUPPORTED );
slot->type = type;
return( PSA_SUCCESS );
}
/****************************************************************/
/* Module setup */
/****************************************************************/
void mbedtls_psa_crypto_free( void )
{
psa_key_slot_t key;
for( key = 1; key <= PSA_KEY_SLOT_COUNT; key++ )
psa_destroy_key( key );
mbedtls_ctr_drbg_free( &global_data.ctr_drbg );
mbedtls_entropy_free( &global_data.entropy );
mbedtls_zeroize( &global_data, sizeof( global_data ) );
}
psa_status_t psa_crypto_init( void )
{
int ret;
const unsigned char drbg_seed[] = "PSA";
if( global_data.initialized != 0 )
return( PSA_SUCCESS );
mbedtls_zeroize( &global_data, sizeof( global_data ) );
mbedtls_entropy_init( &global_data.entropy );
mbedtls_ctr_drbg_init( &global_data.ctr_drbg );
ret = mbedtls_ctr_drbg_seed( &global_data.ctr_drbg,
mbedtls_entropy_func,
&global_data.entropy,
drbg_seed, sizeof( drbg_seed ) - 1 );
if( ret != 0 )
goto exit;
global_data.initialized = 1;
exit:
if( ret != 0 )
mbedtls_psa_crypto_free( );
return( mbedtls_to_psa_error( ret ) );
}
#endif /* MBEDTLS_PSA_CRYPTO_C */