mbedtls/library/cipher.c
Gilles Peskine 87a5e565f4 Rename functions that inject key material to an allocated handle
This commit starts a migration to a new interface for key creation.
Today, the application allocates a handle, then fills its metadata,
and finally injects key material. The new interface fills metadata
into a temporary structure, and a handle is allocated at the same time
it gets filled with both metadata and key material.

This commit was obtained by moving the declaration of the old-style
functions to crypto_extra.h and renaming them with the to_handle
suffix, adding declarations for the new-style functions in crypto.h
under their new name, and running

    perl -i -pe 's/\bpsa_(import|copy|generator_import|generate)_key\b/$&_to_handle/g' library/*.c tests/suites/*.function programs/psa/*.c
    perl -i -pe 's/\bpsa_get_key_lifetime\b/$&_from_handle/g' library/*.c tests/suites/*.function programs/psa/*.c

Many functions that are specific to the old interface, and which will
not remain under the same name with the new interface, are still in
crypto.h for now.

All functional tests should still pass. The documentation may have
some broken links.
2019-04-24 15:24:45 +02:00

1503 lines
46 KiB
C

/**
* \file cipher.c
*
* \brief Generic cipher wrapper for mbed TLS
*
* \author Adriaan de Jong <dejong@fox-it.com>
*
* Copyright (C) 2006-2015, 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_CIPHER_C)
#include "mbedtls/cipher.h"
#include "mbedtls/cipher_internal.h"
#include "mbedtls/platform_util.h"
#include <stdlib.h>
#include <string.h>
#if defined(MBEDTLS_CHACHAPOLY_C)
#include "mbedtls/chachapoly.h"
#endif
#if defined(MBEDTLS_GCM_C)
#include "mbedtls/gcm.h"
#endif
#if defined(MBEDTLS_CCM_C)
#include "mbedtls/ccm.h"
#endif
#if defined(MBEDTLS_CHACHA20_C)
#include "mbedtls/chacha20.h"
#endif
#if defined(MBEDTLS_CMAC_C)
#include "mbedtls/cmac.h"
#endif
#if defined(MBEDTLS_USE_PSA_CRYPTO)
#include "psa/crypto.h"
#include "mbedtls/psa_util.h"
#endif /* MBEDTLS_USE_PSA_CRYPTO */
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#define mbedtls_calloc calloc
#define mbedtls_free free
#endif
#define CIPHER_VALIDATE_RET( cond ) \
MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA )
#define CIPHER_VALIDATE( cond ) \
MBEDTLS_INTERNAL_VALIDATE( cond )
#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
/* Compare the contents of two buffers in constant time.
* Returns 0 if the contents are bitwise identical, otherwise returns
* a non-zero value.
* This is currently only used by GCM and ChaCha20+Poly1305.
*/
static int mbedtls_constant_time_memcmp( const void *v1, const void *v2,
size_t len )
{
const unsigned char *p1 = (const unsigned char*) v1;
const unsigned char *p2 = (const unsigned char*) v2;
size_t i;
unsigned char diff;
for( diff = 0, i = 0; i < len; i++ )
diff |= p1[i] ^ p2[i];
return( (int)diff );
}
#endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
static int supported_init = 0;
const int *mbedtls_cipher_list( void )
{
const mbedtls_cipher_definition_t *def;
int *type;
if( ! supported_init )
{
def = mbedtls_cipher_definitions;
type = mbedtls_cipher_supported;
while( def->type != 0 )
*type++ = (*def++).type;
*type = 0;
supported_init = 1;
}
return( mbedtls_cipher_supported );
}
const mbedtls_cipher_info_t *mbedtls_cipher_info_from_type(
const mbedtls_cipher_type_t cipher_type )
{
const mbedtls_cipher_definition_t *def;
for( def = mbedtls_cipher_definitions; def->info != NULL; def++ )
if( def->type == cipher_type )
return( def->info );
return( NULL );
}
const mbedtls_cipher_info_t *mbedtls_cipher_info_from_string(
const char *cipher_name )
{
const mbedtls_cipher_definition_t *def;
if( NULL == cipher_name )
return( NULL );
for( def = mbedtls_cipher_definitions; def->info != NULL; def++ )
if( ! strcmp( def->info->name, cipher_name ) )
return( def->info );
return( NULL );
}
const mbedtls_cipher_info_t *mbedtls_cipher_info_from_values(
const mbedtls_cipher_id_t cipher_id,
int key_bitlen,
const mbedtls_cipher_mode_t mode )
{
const mbedtls_cipher_definition_t *def;
for( def = mbedtls_cipher_definitions; def->info != NULL; def++ )
if( def->info->base->cipher == cipher_id &&
def->info->key_bitlen == (unsigned) key_bitlen &&
def->info->mode == mode )
return( def->info );
return( NULL );
}
void mbedtls_cipher_init( mbedtls_cipher_context_t *ctx )
{
CIPHER_VALIDATE( ctx != NULL );
memset( ctx, 0, sizeof( mbedtls_cipher_context_t ) );
}
void mbedtls_cipher_free( mbedtls_cipher_context_t *ctx )
{
if( ctx == NULL )
return;
#if defined(MBEDTLS_USE_PSA_CRYPTO)
if( ctx->psa_enabled == 1 )
{
if( ctx->cipher_ctx != NULL )
{
mbedtls_cipher_context_psa * const cipher_psa =
(mbedtls_cipher_context_psa *) ctx->cipher_ctx;
if( cipher_psa->slot_state == MBEDTLS_CIPHER_PSA_KEY_OWNED )
{
/* xxx_free() doesn't allow to return failures. */
(void) psa_destroy_key( cipher_psa->slot );
}
mbedtls_platform_zeroize( cipher_psa, sizeof( *cipher_psa ) );
mbedtls_free( cipher_psa );
}
mbedtls_platform_zeroize( ctx, sizeof(mbedtls_cipher_context_t) );
return;
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
#if defined(MBEDTLS_CMAC_C)
if( ctx->cmac_ctx )
{
mbedtls_platform_zeroize( ctx->cmac_ctx,
sizeof( mbedtls_cmac_context_t ) );
mbedtls_free( ctx->cmac_ctx );
}
#endif
if( ctx->cipher_ctx )
ctx->cipher_info->base->ctx_free_func( ctx->cipher_ctx );
mbedtls_platform_zeroize( ctx, sizeof(mbedtls_cipher_context_t) );
}
int mbedtls_cipher_setup( mbedtls_cipher_context_t *ctx,
const mbedtls_cipher_info_t *cipher_info )
{
CIPHER_VALIDATE_RET( ctx != NULL );
if( cipher_info == NULL )
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
memset( ctx, 0, sizeof( mbedtls_cipher_context_t ) );
if( NULL == ( ctx->cipher_ctx = cipher_info->base->ctx_alloc_func() ) )
return( MBEDTLS_ERR_CIPHER_ALLOC_FAILED );
ctx->cipher_info = cipher_info;
#if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
/*
* Ignore possible errors caused by a cipher mode that doesn't use padding
*/
#if defined(MBEDTLS_CIPHER_PADDING_PKCS7)
(void) mbedtls_cipher_set_padding_mode( ctx, MBEDTLS_PADDING_PKCS7 );
#else
(void) mbedtls_cipher_set_padding_mode( ctx, MBEDTLS_PADDING_NONE );
#endif
#endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
return( 0 );
}
#if defined(MBEDTLS_USE_PSA_CRYPTO)
int mbedtls_cipher_setup_psa( mbedtls_cipher_context_t *ctx,
const mbedtls_cipher_info_t *cipher_info,
size_t taglen )
{
psa_algorithm_t alg;
mbedtls_cipher_context_psa *cipher_psa;
if( NULL == cipher_info || NULL == ctx )
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
/* Check that the underlying cipher mode and cipher type are
* supported by the underlying PSA Crypto implementation. */
alg = mbedtls_psa_translate_cipher_mode( cipher_info->mode, taglen );
if( alg == 0 )
return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
if( mbedtls_psa_translate_cipher_type( cipher_info->type ) == 0 )
return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
memset( ctx, 0, sizeof( mbedtls_cipher_context_t ) );
cipher_psa = mbedtls_calloc( 1, sizeof(mbedtls_cipher_context_psa ) );
if( cipher_psa == NULL )
return( MBEDTLS_ERR_CIPHER_ALLOC_FAILED );
cipher_psa->alg = alg;
ctx->cipher_ctx = cipher_psa;
ctx->cipher_info = cipher_info;
ctx->psa_enabled = 1;
return( 0 );
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
int mbedtls_cipher_setkey( mbedtls_cipher_context_t *ctx,
const unsigned char *key,
int key_bitlen,
const mbedtls_operation_t operation )
{
CIPHER_VALIDATE_RET( ctx != NULL );
CIPHER_VALIDATE_RET( key != NULL );
CIPHER_VALIDATE_RET( operation == MBEDTLS_ENCRYPT ||
operation == MBEDTLS_DECRYPT );
if( ctx->cipher_info == NULL )
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
#if defined(MBEDTLS_USE_PSA_CRYPTO)
if( ctx->psa_enabled == 1 )
{
mbedtls_cipher_context_psa * const cipher_psa =
(mbedtls_cipher_context_psa *) ctx->cipher_ctx;
size_t const key_bytelen = ( (size_t) key_bitlen + 7 ) / 8;
psa_status_t status;
psa_key_type_t key_type;
psa_key_usage_t key_usage;
psa_key_policy_t key_policy;
/* PSA Crypto API only accepts byte-aligned keys. */
if( key_bitlen % 8 != 0 )
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
/* Don't allow keys to be set multiple times. */
if( cipher_psa->slot_state != MBEDTLS_CIPHER_PSA_KEY_UNSET )
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
key_type = mbedtls_psa_translate_cipher_type(
ctx->cipher_info->type );
if( key_type == 0 )
return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
/* Allocate a key slot to use. */
status = psa_allocate_key( &cipher_psa->slot );
if( status != PSA_SUCCESS )
return( MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED );
/* Indicate that we own the key slot and need to
* destroy it in mbedtls_cipher_free(). */
cipher_psa->slot_state = MBEDTLS_CIPHER_PSA_KEY_OWNED;
/* From that point on, the responsibility for destroying the
* key slot is on mbedtls_cipher_free(). This includes the case
* where the policy setup or key import below fail, as
* mbedtls_cipher_free() needs to be called in any case. */
/* Setup policy for the new key slot. */
key_policy = psa_key_policy_init();
/* Mbed TLS' cipher layer doesn't enforce the mode of operation
* (encrypt vs. decrypt): it is possible to setup a key for encryption
* and use it for AEAD decryption. Until tests relying on this
* are changed, allow any usage in PSA. */
/* key_usage = mbedtls_psa_translate_cipher_operation( operation ); */
key_usage = PSA_KEY_USAGE_ENCRYPT | PSA_KEY_USAGE_DECRYPT;
psa_key_policy_set_usage( &key_policy, key_usage, cipher_psa->alg );
status = psa_set_key_policy( cipher_psa->slot, &key_policy );
if( status != PSA_SUCCESS )
return( MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED );
/* Populate new key slot. */
status = psa_import_key_to_handle( cipher_psa->slot,
key_type, key, key_bytelen );
if( status != PSA_SUCCESS )
return( MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED );
ctx->key_bitlen = key_bitlen;
ctx->operation = operation;
return( 0 );
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
if( ( ctx->cipher_info->flags & MBEDTLS_CIPHER_VARIABLE_KEY_LEN ) == 0 &&
(int) ctx->cipher_info->key_bitlen != key_bitlen )
{
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
}
ctx->key_bitlen = key_bitlen;
ctx->operation = operation;
/*
* For OFB, CFB and CTR mode always use the encryption key schedule
*/
if( MBEDTLS_ENCRYPT == operation ||
MBEDTLS_MODE_CFB == ctx->cipher_info->mode ||
MBEDTLS_MODE_OFB == ctx->cipher_info->mode ||
MBEDTLS_MODE_CTR == ctx->cipher_info->mode )
{
return( ctx->cipher_info->base->setkey_enc_func( ctx->cipher_ctx, key,
ctx->key_bitlen ) );
}
if( MBEDTLS_DECRYPT == operation )
return( ctx->cipher_info->base->setkey_dec_func( ctx->cipher_ctx, key,
ctx->key_bitlen ) );
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
}
int mbedtls_cipher_set_iv( mbedtls_cipher_context_t *ctx,
const unsigned char *iv,
size_t iv_len )
{
size_t actual_iv_size;
CIPHER_VALIDATE_RET( ctx != NULL );
CIPHER_VALIDATE_RET( iv_len == 0 || iv != NULL );
if( ctx->cipher_info == NULL )
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
#if defined(MBEDTLS_USE_PSA_CRYPTO)
if( ctx->psa_enabled == 1 )
{
/* While PSA Crypto has an API for multipart
* operations, we currently don't make it
* accessible through the cipher layer. */
return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
/* avoid buffer overflow in ctx->iv */
if( iv_len > MBEDTLS_MAX_IV_LENGTH )
return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
if( ( ctx->cipher_info->flags & MBEDTLS_CIPHER_VARIABLE_IV_LEN ) != 0 )
actual_iv_size = iv_len;
else
{
actual_iv_size = ctx->cipher_info->iv_size;
/* avoid reading past the end of input buffer */
if( actual_iv_size > iv_len )
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
}
#if defined(MBEDTLS_CHACHA20_C)
if ( ctx->cipher_info->type == MBEDTLS_CIPHER_CHACHA20 )
{
if ( 0 != mbedtls_chacha20_starts( (mbedtls_chacha20_context*)ctx->cipher_ctx,
iv,
0U ) ) /* Initial counter value */
{
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
}
}
#endif
if ( actual_iv_size != 0 )
{
memcpy( ctx->iv, iv, actual_iv_size );
ctx->iv_size = actual_iv_size;
}
return( 0 );
}
int mbedtls_cipher_reset( mbedtls_cipher_context_t *ctx )
{
CIPHER_VALIDATE_RET( ctx != NULL );
if( ctx->cipher_info == NULL )
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
#if defined(MBEDTLS_USE_PSA_CRYPTO)
if( ctx->psa_enabled == 1 )
{
/* We don't support resetting PSA-based
* cipher contexts, yet. */
return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
ctx->unprocessed_len = 0;
return( 0 );
}
#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
int mbedtls_cipher_update_ad( mbedtls_cipher_context_t *ctx,
const unsigned char *ad, size_t ad_len )
{
CIPHER_VALIDATE_RET( ctx != NULL );
CIPHER_VALIDATE_RET( ad_len == 0 || ad != NULL );
if( ctx->cipher_info == NULL )
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
#if defined(MBEDTLS_USE_PSA_CRYPTO)
if( ctx->psa_enabled == 1 )
{
/* While PSA Crypto has an API for multipart
* operations, we currently don't make it
* accessible through the cipher layer. */
return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
#if defined(MBEDTLS_GCM_C)
if( MBEDTLS_MODE_GCM == ctx->cipher_info->mode )
{
return( mbedtls_gcm_starts( (mbedtls_gcm_context *) ctx->cipher_ctx, ctx->operation,
ctx->iv, ctx->iv_size, ad, ad_len ) );
}
#endif
#if defined(MBEDTLS_CHACHAPOLY_C)
if (MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type )
{
int result;
mbedtls_chachapoly_mode_t mode;
mode = ( ctx->operation == MBEDTLS_ENCRYPT )
? MBEDTLS_CHACHAPOLY_ENCRYPT
: MBEDTLS_CHACHAPOLY_DECRYPT;
result = mbedtls_chachapoly_starts( (mbedtls_chachapoly_context*) ctx->cipher_ctx,
ctx->iv,
mode );
if ( result != 0 )
return( result );
return( mbedtls_chachapoly_update_aad( (mbedtls_chachapoly_context*) ctx->cipher_ctx,
ad, ad_len ) );
}
#endif
return( 0 );
}
#endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
int mbedtls_cipher_update( mbedtls_cipher_context_t *ctx, const unsigned char *input,
size_t ilen, unsigned char *output, size_t *olen )
{
int ret;
size_t block_size;
CIPHER_VALIDATE_RET( ctx != NULL );
CIPHER_VALIDATE_RET( ilen == 0 || input != NULL );
CIPHER_VALIDATE_RET( output != NULL );
CIPHER_VALIDATE_RET( olen != NULL );
if( ctx->cipher_info == NULL )
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
#if defined(MBEDTLS_USE_PSA_CRYPTO)
if( ctx->psa_enabled == 1 )
{
/* While PSA Crypto has an API for multipart
* operations, we currently don't make it
* accessible through the cipher layer. */
return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
*olen = 0;
block_size = mbedtls_cipher_get_block_size( ctx );
if( ctx->cipher_info->mode == MBEDTLS_MODE_ECB )
{
if( ilen != block_size )
return( MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED );
*olen = ilen;
if( 0 != ( ret = ctx->cipher_info->base->ecb_func( ctx->cipher_ctx,
ctx->operation, input, output ) ) )
{
return( ret );
}
return( 0 );
}
#if defined(MBEDTLS_GCM_C)
if( ctx->cipher_info->mode == MBEDTLS_MODE_GCM )
{
*olen = ilen;
return( mbedtls_gcm_update( (mbedtls_gcm_context *) ctx->cipher_ctx, ilen, input,
output ) );
}
#endif
#if defined(MBEDTLS_CHACHAPOLY_C)
if ( ctx->cipher_info->type == MBEDTLS_CIPHER_CHACHA20_POLY1305 )
{
*olen = ilen;
return( mbedtls_chachapoly_update( (mbedtls_chachapoly_context*) ctx->cipher_ctx,
ilen, input, output ) );
}
#endif
if ( 0 == block_size )
{
return( MBEDTLS_ERR_CIPHER_INVALID_CONTEXT );
}
if( input == output &&
( ctx->unprocessed_len != 0 || ilen % block_size ) )
{
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
}
#if defined(MBEDTLS_CIPHER_MODE_CBC)
if( ctx->cipher_info->mode == MBEDTLS_MODE_CBC )
{
size_t copy_len = 0;
/*
* If there is not enough data for a full block, cache it.
*/
if( ( ctx->operation == MBEDTLS_DECRYPT && NULL != ctx->add_padding &&
ilen <= block_size - ctx->unprocessed_len ) ||
( ctx->operation == MBEDTLS_DECRYPT && NULL == ctx->add_padding &&
ilen < block_size - ctx->unprocessed_len ) ||
( ctx->operation == MBEDTLS_ENCRYPT &&
ilen < block_size - ctx->unprocessed_len ) )
{
memcpy( &( ctx->unprocessed_data[ctx->unprocessed_len] ), input,
ilen );
ctx->unprocessed_len += ilen;
return( 0 );
}
/*
* Process cached data first
*/
if( 0 != ctx->unprocessed_len )
{
copy_len = block_size - ctx->unprocessed_len;
memcpy( &( ctx->unprocessed_data[ctx->unprocessed_len] ), input,
copy_len );
if( 0 != ( ret = ctx->cipher_info->base->cbc_func( ctx->cipher_ctx,
ctx->operation, block_size, ctx->iv,
ctx->unprocessed_data, output ) ) )
{
return( ret );
}
*olen += block_size;
output += block_size;
ctx->unprocessed_len = 0;
input += copy_len;
ilen -= copy_len;
}
/*
* Cache final, incomplete block
*/
if( 0 != ilen )
{
if( 0 == block_size )
{
return( MBEDTLS_ERR_CIPHER_INVALID_CONTEXT );
}
/* Encryption: only cache partial blocks
* Decryption w/ padding: always keep at least one whole block
* Decryption w/o padding: only cache partial blocks
*/
copy_len = ilen % block_size;
if( copy_len == 0 &&
ctx->operation == MBEDTLS_DECRYPT &&
NULL != ctx->add_padding)
{
copy_len = block_size;
}
memcpy( ctx->unprocessed_data, &( input[ilen - copy_len] ),
copy_len );
ctx->unprocessed_len += copy_len;
ilen -= copy_len;
}
/*
* Process remaining full blocks
*/
if( ilen )
{
if( 0 != ( ret = ctx->cipher_info->base->cbc_func( ctx->cipher_ctx,
ctx->operation, ilen, ctx->iv, input, output ) ) )
{
return( ret );
}
*olen += ilen;
}
return( 0 );
}
#endif /* MBEDTLS_CIPHER_MODE_CBC */
#if defined(MBEDTLS_CIPHER_MODE_CFB)
if( ctx->cipher_info->mode == MBEDTLS_MODE_CFB )
{
if( 0 != ( ret = ctx->cipher_info->base->cfb_func( ctx->cipher_ctx,
ctx->operation, ilen, &ctx->unprocessed_len, ctx->iv,
input, output ) ) )
{
return( ret );
}
*olen = ilen;
return( 0 );
}
#endif /* MBEDTLS_CIPHER_MODE_CFB */
#if defined(MBEDTLS_CIPHER_MODE_OFB)
if( ctx->cipher_info->mode == MBEDTLS_MODE_OFB )
{
if( 0 != ( ret = ctx->cipher_info->base->ofb_func( ctx->cipher_ctx,
ilen, &ctx->unprocessed_len, ctx->iv, input, output ) ) )
{
return( ret );
}
*olen = ilen;
return( 0 );
}
#endif /* MBEDTLS_CIPHER_MODE_OFB */
#if defined(MBEDTLS_CIPHER_MODE_CTR)
if( ctx->cipher_info->mode == MBEDTLS_MODE_CTR )
{
if( 0 != ( ret = ctx->cipher_info->base->ctr_func( ctx->cipher_ctx,
ilen, &ctx->unprocessed_len, ctx->iv,
ctx->unprocessed_data, input, output ) ) )
{
return( ret );
}
*olen = ilen;
return( 0 );
}
#endif /* MBEDTLS_CIPHER_MODE_CTR */
#if defined(MBEDTLS_CIPHER_MODE_XTS)
if( ctx->cipher_info->mode == MBEDTLS_MODE_XTS )
{
if( ctx->unprocessed_len > 0 ) {
/* We can only process an entire data unit at a time. */
return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
}
ret = ctx->cipher_info->base->xts_func( ctx->cipher_ctx,
ctx->operation, ilen, ctx->iv, input, output );
if( ret != 0 )
{
return( ret );
}
*olen = ilen;
return( 0 );
}
#endif /* MBEDTLS_CIPHER_MODE_XTS */
#if defined(MBEDTLS_CIPHER_MODE_STREAM)
if( ctx->cipher_info->mode == MBEDTLS_MODE_STREAM )
{
if( 0 != ( ret = ctx->cipher_info->base->stream_func( ctx->cipher_ctx,
ilen, input, output ) ) )
{
return( ret );
}
*olen = ilen;
return( 0 );
}
#endif /* MBEDTLS_CIPHER_MODE_STREAM */
return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
}
#if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
#if defined(MBEDTLS_CIPHER_PADDING_PKCS7)
/*
* PKCS7 (and PKCS5) padding: fill with ll bytes, with ll = padding_len
*/
static void add_pkcs_padding( unsigned char *output, size_t output_len,
size_t data_len )
{
size_t padding_len = output_len - data_len;
unsigned char i;
for( i = 0; i < padding_len; i++ )
output[data_len + i] = (unsigned char) padding_len;
}
static int get_pkcs_padding( unsigned char *input, size_t input_len,
size_t *data_len )
{
size_t i, pad_idx;
unsigned char padding_len, bad = 0;
if( NULL == input || NULL == data_len )
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
padding_len = input[input_len - 1];
*data_len = input_len - padding_len;
/* Avoid logical || since it results in a branch */
bad |= padding_len > input_len;
bad |= padding_len == 0;
/* The number of bytes checked must be independent of padding_len,
* so pick input_len, which is usually 8 or 16 (one block) */
pad_idx = input_len - padding_len;
for( i = 0; i < input_len; i++ )
bad |= ( input[i] ^ padding_len ) * ( i >= pad_idx );
return( MBEDTLS_ERR_CIPHER_INVALID_PADDING * ( bad != 0 ) );
}
#endif /* MBEDTLS_CIPHER_PADDING_PKCS7 */
#if defined(MBEDTLS_CIPHER_PADDING_ONE_AND_ZEROS)
/*
* One and zeros padding: fill with 80 00 ... 00
*/
static void add_one_and_zeros_padding( unsigned char *output,
size_t output_len, size_t data_len )
{
size_t padding_len = output_len - data_len;
unsigned char i = 0;
output[data_len] = 0x80;
for( i = 1; i < padding_len; i++ )
output[data_len + i] = 0x00;
}
static int get_one_and_zeros_padding( unsigned char *input, size_t input_len,
size_t *data_len )
{
size_t i;
unsigned char done = 0, prev_done, bad;
if( NULL == input || NULL == data_len )
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
bad = 0x80;
*data_len = 0;
for( i = input_len; i > 0; i-- )
{
prev_done = done;
done |= ( input[i - 1] != 0 );
*data_len |= ( i - 1 ) * ( done != prev_done );
bad ^= input[i - 1] * ( done != prev_done );
}
return( MBEDTLS_ERR_CIPHER_INVALID_PADDING * ( bad != 0 ) );
}
#endif /* MBEDTLS_CIPHER_PADDING_ONE_AND_ZEROS */
#if defined(MBEDTLS_CIPHER_PADDING_ZEROS_AND_LEN)
/*
* Zeros and len padding: fill with 00 ... 00 ll, where ll is padding length
*/
static void add_zeros_and_len_padding( unsigned char *output,
size_t output_len, size_t data_len )
{
size_t padding_len = output_len - data_len;
unsigned char i = 0;
for( i = 1; i < padding_len; i++ )
output[data_len + i - 1] = 0x00;
output[output_len - 1] = (unsigned char) padding_len;
}
static int get_zeros_and_len_padding( unsigned char *input, size_t input_len,
size_t *data_len )
{
size_t i, pad_idx;
unsigned char padding_len, bad = 0;
if( NULL == input || NULL == data_len )
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
padding_len = input[input_len - 1];
*data_len = input_len - padding_len;
/* Avoid logical || since it results in a branch */
bad |= padding_len > input_len;
bad |= padding_len == 0;
/* The number of bytes checked must be independent of padding_len */
pad_idx = input_len - padding_len;
for( i = 0; i < input_len - 1; i++ )
bad |= input[i] * ( i >= pad_idx );
return( MBEDTLS_ERR_CIPHER_INVALID_PADDING * ( bad != 0 ) );
}
#endif /* MBEDTLS_CIPHER_PADDING_ZEROS_AND_LEN */
#if defined(MBEDTLS_CIPHER_PADDING_ZEROS)
/*
* Zero padding: fill with 00 ... 00
*/
static void add_zeros_padding( unsigned char *output,
size_t output_len, size_t data_len )
{
size_t i;
for( i = data_len; i < output_len; i++ )
output[i] = 0x00;
}
static int get_zeros_padding( unsigned char *input, size_t input_len,
size_t *data_len )
{
size_t i;
unsigned char done = 0, prev_done;
if( NULL == input || NULL == data_len )
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
*data_len = 0;
for( i = input_len; i > 0; i-- )
{
prev_done = done;
done |= ( input[i-1] != 0 );
*data_len |= i * ( done != prev_done );
}
return( 0 );
}
#endif /* MBEDTLS_CIPHER_PADDING_ZEROS */
/*
* No padding: don't pad :)
*
* There is no add_padding function (check for NULL in mbedtls_cipher_finish)
* but a trivial get_padding function
*/
static int get_no_padding( unsigned char *input, size_t input_len,
size_t *data_len )
{
if( NULL == input || NULL == data_len )
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
*data_len = input_len;
return( 0 );
}
#endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
int mbedtls_cipher_finish( mbedtls_cipher_context_t *ctx,
unsigned char *output, size_t *olen )
{
CIPHER_VALIDATE_RET( ctx != NULL );
CIPHER_VALIDATE_RET( output != NULL );
CIPHER_VALIDATE_RET( olen != NULL );
if( ctx->cipher_info == NULL )
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
#if defined(MBEDTLS_USE_PSA_CRYPTO)
if( ctx->psa_enabled == 1 )
{
/* While PSA Crypto has an API for multipart
* operations, we currently don't make it
* accessible through the cipher layer. */
return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
*olen = 0;
if( MBEDTLS_MODE_CFB == ctx->cipher_info->mode ||
MBEDTLS_MODE_OFB == ctx->cipher_info->mode ||
MBEDTLS_MODE_CTR == ctx->cipher_info->mode ||
MBEDTLS_MODE_GCM == ctx->cipher_info->mode ||
MBEDTLS_MODE_XTS == ctx->cipher_info->mode ||
MBEDTLS_MODE_STREAM == ctx->cipher_info->mode )
{
return( 0 );
}
if ( ( MBEDTLS_CIPHER_CHACHA20 == ctx->cipher_info->type ) ||
( MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type ) )
{
return( 0 );
}
if( MBEDTLS_MODE_ECB == ctx->cipher_info->mode )
{
if( ctx->unprocessed_len != 0 )
return( MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED );
return( 0 );
}
#if defined(MBEDTLS_CIPHER_MODE_CBC)
if( MBEDTLS_MODE_CBC == ctx->cipher_info->mode )
{
int ret = 0;
if( MBEDTLS_ENCRYPT == ctx->operation )
{
/* check for 'no padding' mode */
if( NULL == ctx->add_padding )
{
if( 0 != ctx->unprocessed_len )
return( MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED );
return( 0 );
}
ctx->add_padding( ctx->unprocessed_data, mbedtls_cipher_get_iv_size( ctx ),
ctx->unprocessed_len );
}
else if( mbedtls_cipher_get_block_size( ctx ) != ctx->unprocessed_len )
{
/*
* For decrypt operations, expect a full block,
* or an empty block if no padding
*/
if( NULL == ctx->add_padding && 0 == ctx->unprocessed_len )
return( 0 );
return( MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED );
}
/* cipher block */
if( 0 != ( ret = ctx->cipher_info->base->cbc_func( ctx->cipher_ctx,
ctx->operation, mbedtls_cipher_get_block_size( ctx ), ctx->iv,
ctx->unprocessed_data, output ) ) )
{
return( ret );
}
/* Set output size for decryption */
if( MBEDTLS_DECRYPT == ctx->operation )
return( ctx->get_padding( output, mbedtls_cipher_get_block_size( ctx ),
olen ) );
/* Set output size for encryption */
*olen = mbedtls_cipher_get_block_size( ctx );
return( 0 );
}
#else
((void) output);
#endif /* MBEDTLS_CIPHER_MODE_CBC */
return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
}
#if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
int mbedtls_cipher_set_padding_mode( mbedtls_cipher_context_t *ctx,
mbedtls_cipher_padding_t mode )
{
CIPHER_VALIDATE_RET( ctx != NULL );
if( NULL == ctx->cipher_info || MBEDTLS_MODE_CBC != ctx->cipher_info->mode )
{
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
}
#if defined(MBEDTLS_USE_PSA_CRYPTO)
if( ctx->psa_enabled == 1 )
{
/* While PSA Crypto knows about CBC padding
* schemes, we currently don't make them
* accessible through the cipher layer. */
if( mode != MBEDTLS_PADDING_NONE )
return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
return( 0 );
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
switch( mode )
{
#if defined(MBEDTLS_CIPHER_PADDING_PKCS7)
case MBEDTLS_PADDING_PKCS7:
ctx->add_padding = add_pkcs_padding;
ctx->get_padding = get_pkcs_padding;
break;
#endif
#if defined(MBEDTLS_CIPHER_PADDING_ONE_AND_ZEROS)
case MBEDTLS_PADDING_ONE_AND_ZEROS:
ctx->add_padding = add_one_and_zeros_padding;
ctx->get_padding = get_one_and_zeros_padding;
break;
#endif
#if defined(MBEDTLS_CIPHER_PADDING_ZEROS_AND_LEN)
case MBEDTLS_PADDING_ZEROS_AND_LEN:
ctx->add_padding = add_zeros_and_len_padding;
ctx->get_padding = get_zeros_and_len_padding;
break;
#endif
#if defined(MBEDTLS_CIPHER_PADDING_ZEROS)
case MBEDTLS_PADDING_ZEROS:
ctx->add_padding = add_zeros_padding;
ctx->get_padding = get_zeros_padding;
break;
#endif
case MBEDTLS_PADDING_NONE:
ctx->add_padding = NULL;
ctx->get_padding = get_no_padding;
break;
default:
return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
}
return( 0 );
}
#endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
int mbedtls_cipher_write_tag( mbedtls_cipher_context_t *ctx,
unsigned char *tag, size_t tag_len )
{
CIPHER_VALIDATE_RET( ctx != NULL );
CIPHER_VALIDATE_RET( tag_len == 0 || tag != NULL );
if( ctx->cipher_info == NULL )
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
if( MBEDTLS_ENCRYPT != ctx->operation )
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
#if defined(MBEDTLS_USE_PSA_CRYPTO)
if( ctx->psa_enabled == 1 )
{
/* While PSA Crypto has an API for multipart
* operations, we currently don't make it
* accessible through the cipher layer. */
return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
#if defined(MBEDTLS_GCM_C)
if( MBEDTLS_MODE_GCM == ctx->cipher_info->mode )
return( mbedtls_gcm_finish( (mbedtls_gcm_context *) ctx->cipher_ctx,
tag, tag_len ) );
#endif
#if defined(MBEDTLS_CHACHAPOLY_C)
if ( MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type )
{
/* Don't allow truncated MAC for Poly1305 */
if ( tag_len != 16U )
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
return( mbedtls_chachapoly_finish(
(mbedtls_chachapoly_context*) ctx->cipher_ctx, tag ) );
}
#endif
return( 0 );
}
int mbedtls_cipher_check_tag( mbedtls_cipher_context_t *ctx,
const unsigned char *tag, size_t tag_len )
{
unsigned char check_tag[16];
int ret;
CIPHER_VALIDATE_RET( ctx != NULL );
CIPHER_VALIDATE_RET( tag_len == 0 || tag != NULL );
if( ctx->cipher_info == NULL )
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
if( MBEDTLS_DECRYPT != ctx->operation )
{
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
}
#if defined(MBEDTLS_USE_PSA_CRYPTO)
if( ctx->psa_enabled == 1 )
{
/* While PSA Crypto has an API for multipart
* operations, we currently don't make it
* accessible through the cipher layer. */
return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
#if defined(MBEDTLS_GCM_C)
if( MBEDTLS_MODE_GCM == ctx->cipher_info->mode )
{
if( tag_len > sizeof( check_tag ) )
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
if( 0 != ( ret = mbedtls_gcm_finish(
(mbedtls_gcm_context *) ctx->cipher_ctx,
check_tag, tag_len ) ) )
{
return( ret );
}
/* Check the tag in "constant-time" */
if( mbedtls_constant_time_memcmp( tag, check_tag, tag_len ) != 0 )
return( MBEDTLS_ERR_CIPHER_AUTH_FAILED );
return( 0 );
}
#endif /* MBEDTLS_GCM_C */
#if defined(MBEDTLS_CHACHAPOLY_C)
if ( MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type )
{
/* Don't allow truncated MAC for Poly1305 */
if ( tag_len != sizeof( check_tag ) )
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
ret = mbedtls_chachapoly_finish(
(mbedtls_chachapoly_context*) ctx->cipher_ctx, check_tag );
if ( ret != 0 )
{
return( ret );
}
/* Check the tag in "constant-time" */
if( mbedtls_constant_time_memcmp( tag, check_tag, tag_len ) != 0 )
return( MBEDTLS_ERR_CIPHER_AUTH_FAILED );
return( 0 );
}
#endif /* MBEDTLS_CHACHAPOLY_C */
return( 0 );
}
#endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
/*
* Packet-oriented wrapper for non-AEAD modes
*/
int mbedtls_cipher_crypt( mbedtls_cipher_context_t *ctx,
const unsigned char *iv, size_t iv_len,
const unsigned char *input, size_t ilen,
unsigned char *output, size_t *olen )
{
int ret;
size_t finish_olen;
CIPHER_VALIDATE_RET( ctx != NULL );
CIPHER_VALIDATE_RET( iv_len == 0 || iv != NULL );
CIPHER_VALIDATE_RET( ilen == 0 || input != NULL );
CIPHER_VALIDATE_RET( output != NULL );
CIPHER_VALIDATE_RET( olen != NULL );
#if defined(MBEDTLS_USE_PSA_CRYPTO)
if( ctx->psa_enabled == 1 )
{
/* As in the non-PSA case, we don't check that
* a key has been set. If not, the key slot will
* still be in its default state of 0, which is
* guaranteed to be invalid, hence the PSA-call
* below will gracefully fail. */
mbedtls_cipher_context_psa * const cipher_psa =
(mbedtls_cipher_context_psa *) ctx->cipher_ctx;
psa_status_t status;
psa_cipher_operation_t cipher_op = PSA_CIPHER_OPERATION_INIT;
size_t part_len;
if( ctx->operation == MBEDTLS_DECRYPT )
{
status = psa_cipher_decrypt_setup( &cipher_op,
cipher_psa->slot,
cipher_psa->alg );
}
else if( ctx->operation == MBEDTLS_ENCRYPT )
{
status = psa_cipher_encrypt_setup( &cipher_op,
cipher_psa->slot,
cipher_psa->alg );
}
else
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
/* In the following, we can immediately return on an error,
* because the PSA Crypto API guarantees that cipher operations
* are terminated by unsuccessful calls to psa_cipher_update(),
* and by any call to psa_cipher_finish(). */
if( status != PSA_SUCCESS )
return( MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED );
status = psa_cipher_set_iv( &cipher_op, iv, iv_len );
if( status != PSA_SUCCESS )
return( MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED );
status = psa_cipher_update( &cipher_op,
input, ilen,
output, ilen, olen );
if( status != PSA_SUCCESS )
return( MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED );
status = psa_cipher_finish( &cipher_op,
output + *olen, ilen - *olen,
&part_len );
if( status != PSA_SUCCESS )
return( MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED );
*olen += part_len;
return( 0 );
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
if( ( ret = mbedtls_cipher_set_iv( ctx, iv, iv_len ) ) != 0 )
return( ret );
if( ( ret = mbedtls_cipher_reset( ctx ) ) != 0 )
return( ret );
if( ( ret = mbedtls_cipher_update( ctx, input, ilen,
output, olen ) ) != 0 )
return( ret );
if( ( ret = mbedtls_cipher_finish( ctx, output + *olen,
&finish_olen ) ) != 0 )
return( ret );
*olen += finish_olen;
return( 0 );
}
#if defined(MBEDTLS_CIPHER_MODE_AEAD)
/*
* Packet-oriented encryption for AEAD modes
*/
int mbedtls_cipher_auth_encrypt( mbedtls_cipher_context_t *ctx,
const unsigned char *iv, size_t iv_len,
const unsigned char *ad, size_t ad_len,
const unsigned char *input, size_t ilen,
unsigned char *output, size_t *olen,
unsigned char *tag, size_t tag_len )
{
CIPHER_VALIDATE_RET( ctx != NULL );
CIPHER_VALIDATE_RET( iv != NULL );
CIPHER_VALIDATE_RET( ad_len == 0 || ad != NULL );
CIPHER_VALIDATE_RET( ilen == 0 || input != NULL );
CIPHER_VALIDATE_RET( output != NULL );
CIPHER_VALIDATE_RET( olen != NULL );
CIPHER_VALIDATE_RET( tag_len == 0 || tag != NULL );
#if defined(MBEDTLS_USE_PSA_CRYPTO)
if( ctx->psa_enabled == 1 )
{
/* As in the non-PSA case, we don't check that
* a key has been set. If not, the key slot will
* still be in its default state of 0, which is
* guaranteed to be invalid, hence the PSA-call
* below will gracefully fail. */
mbedtls_cipher_context_psa * const cipher_psa =
(mbedtls_cipher_context_psa *) ctx->cipher_ctx;
psa_status_t status;
/* PSA Crypto API always writes the authentication tag
* at the end of the encrypted message. */
if( tag != output + ilen )
return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
status = psa_aead_encrypt( cipher_psa->slot,
cipher_psa->alg,
iv, iv_len,
ad, ad_len,
input, ilen,
output, ilen + tag_len, olen );
if( status != PSA_SUCCESS )
return( MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED );
*olen -= tag_len;
return( 0 );
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
#if defined(MBEDTLS_GCM_C)
if( MBEDTLS_MODE_GCM == ctx->cipher_info->mode )
{
*olen = ilen;
return( mbedtls_gcm_crypt_and_tag( ctx->cipher_ctx, MBEDTLS_GCM_ENCRYPT,
ilen, iv, iv_len, ad, ad_len,
input, output, tag_len, tag ) );
}
#endif /* MBEDTLS_GCM_C */
#if defined(MBEDTLS_CCM_C)
if( MBEDTLS_MODE_CCM == ctx->cipher_info->mode )
{
*olen = ilen;
return( mbedtls_ccm_encrypt_and_tag( ctx->cipher_ctx, ilen,
iv, iv_len, ad, ad_len, input, output,
tag, tag_len ) );
}
#endif /* MBEDTLS_CCM_C */
#if defined(MBEDTLS_CHACHAPOLY_C)
if ( MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type )
{
/* ChachaPoly has fixed length nonce and MAC (tag) */
if ( ( iv_len != ctx->cipher_info->iv_size ) ||
( tag_len != 16U ) )
{
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
}
*olen = ilen;
return( mbedtls_chachapoly_encrypt_and_tag( ctx->cipher_ctx,
ilen, iv, ad, ad_len, input, output, tag ) );
}
#endif /* MBEDTLS_CHACHAPOLY_C */
return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
}
/*
* Packet-oriented decryption for AEAD modes
*/
int mbedtls_cipher_auth_decrypt( mbedtls_cipher_context_t *ctx,
const unsigned char *iv, size_t iv_len,
const unsigned char *ad, size_t ad_len,
const unsigned char *input, size_t ilen,
unsigned char *output, size_t *olen,
const unsigned char *tag, size_t tag_len )
{
CIPHER_VALIDATE_RET( ctx != NULL );
CIPHER_VALIDATE_RET( iv != NULL );
CIPHER_VALIDATE_RET( ad_len == 0 || ad != NULL );
CIPHER_VALIDATE_RET( ilen == 0 || input != NULL );
CIPHER_VALIDATE_RET( output != NULL );
CIPHER_VALIDATE_RET( olen != NULL );
CIPHER_VALIDATE_RET( tag_len == 0 || tag != NULL );
#if defined(MBEDTLS_USE_PSA_CRYPTO)
if( ctx->psa_enabled == 1 )
{
/* As in the non-PSA case, we don't check that
* a key has been set. If not, the key slot will
* still be in its default state of 0, which is
* guaranteed to be invalid, hence the PSA-call
* below will gracefully fail. */
mbedtls_cipher_context_psa * const cipher_psa =
(mbedtls_cipher_context_psa *) ctx->cipher_ctx;
psa_status_t status;
/* PSA Crypto API always writes the authentication tag
* at the end of the encrypted message. */
if( tag != input + ilen )
return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
status = psa_aead_decrypt( cipher_psa->slot,
cipher_psa->alg,
iv, iv_len,
ad, ad_len,
input, ilen + tag_len,
output, ilen, olen );
if( status == PSA_ERROR_INVALID_SIGNATURE )
return( MBEDTLS_ERR_CIPHER_AUTH_FAILED );
else if( status != PSA_SUCCESS )
return( MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED );
return( 0 );
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
#if defined(MBEDTLS_GCM_C)
if( MBEDTLS_MODE_GCM == ctx->cipher_info->mode )
{
int ret;
*olen = ilen;
ret = mbedtls_gcm_auth_decrypt( ctx->cipher_ctx, ilen,
iv, iv_len, ad, ad_len,
tag, tag_len, input, output );
if( ret == MBEDTLS_ERR_GCM_AUTH_FAILED )
ret = MBEDTLS_ERR_CIPHER_AUTH_FAILED;
return( ret );
}
#endif /* MBEDTLS_GCM_C */
#if defined(MBEDTLS_CCM_C)
if( MBEDTLS_MODE_CCM == ctx->cipher_info->mode )
{
int ret;
*olen = ilen;
ret = mbedtls_ccm_auth_decrypt( ctx->cipher_ctx, ilen,
iv, iv_len, ad, ad_len,
input, output, tag, tag_len );
if( ret == MBEDTLS_ERR_CCM_AUTH_FAILED )
ret = MBEDTLS_ERR_CIPHER_AUTH_FAILED;
return( ret );
}
#endif /* MBEDTLS_CCM_C */
#if defined(MBEDTLS_CHACHAPOLY_C)
if ( MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type )
{
int ret;
/* ChachaPoly has fixed length nonce and MAC (tag) */
if ( ( iv_len != ctx->cipher_info->iv_size ) ||
( tag_len != 16U ) )
{
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
}
*olen = ilen;
ret = mbedtls_chachapoly_auth_decrypt( ctx->cipher_ctx, ilen,
iv, ad, ad_len, tag, input, output );
if( ret == MBEDTLS_ERR_CHACHAPOLY_AUTH_FAILED )
ret = MBEDTLS_ERR_CIPHER_AUTH_FAILED;
return( ret );
}
#endif /* MBEDTLS_CHACHAPOLY_C */
return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
}
#endif /* MBEDTLS_CIPHER_MODE_AEAD */
#endif /* MBEDTLS_CIPHER_C */