/*
* PSA ITS simulator over stdio files.
*/
/*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#if defined(MBEDTLS_CONFIG_FILE)
#include MBEDTLS_CONFIG_FILE
#else
#include "mbedtls/config.h"
#endif
#if defined(MBEDTLS_PSA_ITS_FILE_C)
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#define mbedtls_snprintf snprintf
#endif
#if defined(_WIN32)
#include <windows.h>
#endif
#include "psa_crypto_its.h"
#include <limits.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#if !defined(PSA_ITS_STORAGE_PREFIX)
#define PSA_ITS_STORAGE_PREFIX ""
#endif
#define PSA_ITS_STORAGE_FILENAME_PATTERN "%08x%08x"
#define PSA_ITS_STORAGE_SUFFIX ".psa_its"
#define PSA_ITS_STORAGE_FILENAME_LENGTH \
( sizeof( PSA_ITS_STORAGE_PREFIX ) - 1 + /*prefix without terminating 0*/ \
16 + /*UID (64-bit number in hex)*/ \
sizeof( PSA_ITS_STORAGE_SUFFIX ) - 1 + /*suffix without terminating 0*/ \
1 /*terminating null byte*/ )
#define PSA_ITS_STORAGE_TEMP \
PSA_ITS_STORAGE_PREFIX "tempfile" PSA_ITS_STORAGE_SUFFIX
/* The maximum value of psa_storage_info_t.size */
#define PSA_ITS_MAX_SIZE 0xffffffff
#define PSA_ITS_MAGIC_STRING "PSA\0ITS\0"
#define PSA_ITS_MAGIC_LENGTH 8
/* As rename fails on Windows if the new filepath already exists,
* use MoveFileExA with the MOVEFILE_REPLACE_EXISTING flag instead.
* Returns 0 on success, nonzero on failure. */
#if defined(_WIN32)
#define rename_replace_existing( oldpath, newpath ) \
( ! MoveFileExA( oldpath, newpath, MOVEFILE_REPLACE_EXISTING ) )
#else
#define rename_replace_existing( oldpath, newpath ) rename( oldpath, newpath )
#endif
typedef struct {
uint8_t magic[PSA_ITS_MAGIC_LENGTH];
uint8_t size[sizeof(uint32_t)];
uint8_t flags[sizeof(psa_storage_create_flags_t)];
} psa_its_file_header_t;
static void psa_its_fill_filename(psa_storage_uid_t uid, char *filename) {
/* Break up the UID into two 32-bit pieces so as not to rely on
* long long support in snprintf. */
mbedtls_snprintf(filename, PSA_ITS_STORAGE_FILENAME_LENGTH,
"%s" PSA_ITS_STORAGE_FILENAME_PATTERN "%s",
PSA_ITS_STORAGE_PREFIX,
(unsigned)(uid >> 32),
(unsigned)(uid & 0xffffffff),
PSA_ITS_STORAGE_SUFFIX);
}
static psa_status_t psa_its_read_file(psa_storage_uid_t uid,
struct psa_storage_info_t *p_info,
FILE **p_stream) {
char filename[PSA_ITS_STORAGE_FILENAME_LENGTH];
psa_its_file_header_t header;
size_t n;
*p_stream = NULL;
psa_its_fill_filename(uid, filename);
*p_stream = fopen(filename, "rb");
if (*p_stream == NULL)
return (PSA_ERROR_DOES_NOT_EXIST);
n = fread(&header, 1, sizeof(header), *p_stream);
if (n != sizeof(header))
return (PSA_ERROR_DATA_CORRUPT);
if (memcmp(header.magic, PSA_ITS_MAGIC_STRING,
PSA_ITS_MAGIC_LENGTH) != 0)
return (PSA_ERROR_DATA_CORRUPT);
p_info->size = (header.size[0] |
header.size[1] << 8 |
header.size[2] << 16 |
header.size[3] << 24);
p_info->flags = (header.flags[0] |
header.flags[1] << 8 |
header.flags[2] << 16 |
header.flags[3] << 24);
return (PSA_SUCCESS);
}
psa_status_t psa_its_get_info(psa_storage_uid_t uid,
struct psa_storage_info_t *p_info) {
psa_status_t status;
FILE *stream = NULL;
status = psa_its_read_file(uid, p_info, &stream);
if (stream != NULL)
fclose(stream);
return (status);
}
psa_status_t psa_its_get(psa_storage_uid_t uid,
uint32_t data_offset,
uint32_t data_length,
void *p_data,
size_t *p_data_length) {
psa_status_t status;
FILE *stream = NULL;
size_t n;
struct psa_storage_info_t info;
status = psa_its_read_file(uid, &info, &stream);
if (status != PSA_SUCCESS)
goto exit;
status = PSA_ERROR_INVALID_ARGUMENT;
if (data_offset + data_length < data_offset)
goto exit;
#if SIZE_MAX < 0xffffffff
if (data_offset + data_length > SIZE_MAX)
goto exit;
#endif
if (data_offset + data_length > info.size)
goto exit;
status = PSA_ERROR_STORAGE_FAILURE;
#if LONG_MAX < 0xffffffff
while (data_offset > LONG_MAX) {
if (fseek(stream, LONG_MAX, SEEK_CUR) != 0)
goto exit;
data_offset -= LONG_MAX;
}
#endif
if (fseek(stream, data_offset, SEEK_CUR) != 0)
goto exit;
n = fread(p_data, 1, data_length, stream);
if (n != data_length)
goto exit;
status = PSA_SUCCESS;
if (p_data_length != NULL)
*p_data_length = n;
exit:
if (stream != NULL)
fclose(stream);
return (status);
}
psa_status_t psa_its_set(psa_storage_uid_t uid,
uint32_t data_length,
const void *p_data,
psa_storage_create_flags_t create_flags) {
psa_status_t status = PSA_ERROR_STORAGE_FAILURE;
char filename[PSA_ITS_STORAGE_FILENAME_LENGTH];
FILE *stream = NULL;
psa_its_file_header_t header;
size_t n;
memcpy(header.magic, PSA_ITS_MAGIC_STRING, PSA_ITS_MAGIC_LENGTH);
header.size[0] = data_length & 0xff;
header.size[1] = (data_length >> 8) & 0xff;
header.size[2] = (data_length >> 16) & 0xff;
header.size[3] = (data_length >> 24) & 0xff;
header.flags[0] = create_flags & 0xff;
header.flags[1] = (create_flags >> 8) & 0xff;
header.flags[2] = (create_flags >> 16) & 0xff;
header.flags[3] = (create_flags >> 24) & 0xff;
psa_its_fill_filename(uid, filename);
stream = fopen(PSA_ITS_STORAGE_TEMP, "wb");
if (stream == NULL)
goto exit;
status = PSA_ERROR_INSUFFICIENT_STORAGE;
n = fwrite(&header, 1, sizeof(header), stream);
if (n != sizeof(header))
goto exit;
if (data_length != 0) {
n = fwrite(p_data, 1, data_length, stream);
if (n != data_length)
goto exit;
}
status = PSA_SUCCESS;
exit:
if (stream != NULL) {
int ret = fclose(stream);
if (status == PSA_SUCCESS && ret != 0)
status = PSA_ERROR_INSUFFICIENT_STORAGE;
}
if (status == PSA_SUCCESS) {
if (rename_replace_existing(PSA_ITS_STORAGE_TEMP, filename) != 0)
status = PSA_ERROR_STORAGE_FAILURE;
}
/* The temporary file may still exist, but only in failure cases where
* we're already reporting an error. So there's nothing we can do on
* failure. If the function succeeded, and in some error cases, the
* temporary file doesn't exist and so remove() is expected to fail.
* Thus we just ignore the return status of remove(). */
(void) remove(PSA_ITS_STORAGE_TEMP);
return (status);
}
psa_status_t psa_its_remove(psa_storage_uid_t uid) {
char filename[PSA_ITS_STORAGE_FILENAME_LENGTH];
FILE *stream;
psa_its_fill_filename(uid, filename);
stream = fopen(filename, "rb");
if (stream == NULL)
return (PSA_ERROR_DOES_NOT_EXIST);
fclose(stream);
if (remove(filename) != 0)
return (PSA_ERROR_STORAGE_FAILURE);
return (PSA_SUCCESS);
}
#endif /* MBEDTLS_PSA_ITS_FILE_C */