library/psa_its_file.c - platform/external/mbedtls - Git at Google

 /*
  *  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.
  */

 #include "common.h"

 #if defined(MBEDTLS_PSA_ITS_FILE_C)

 #include "mbedtls/platform.h"

 #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;
     }

     /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
     mbedtls_setbuf(*p_stream, NULL);

     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)
 {
     if (uid == 0) {
         return PSA_ERROR_INVALID_HANDLE;
     }

     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);
     MBEDTLS_PUT_UINT32_LE(data_length, header.size, 0);
     MBEDTLS_PUT_UINT32_LE(create_flags, header.flags, 0);

     psa_its_fill_filename(uid, filename);
     stream = fopen(PSA_ITS_STORAGE_TEMP, "wb");

     if (stream == NULL) {
         goto exit;
     }

     /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
     mbedtls_setbuf(stream, NULL);

     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 */
	/*
	* 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.
	*/

	#include "common.h"

	#if defined(MBEDTLS_PSA_ITS_FILE_C)

	#include "mbedtls/platform.h"

	#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;
	}

	/* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
	mbedtls_setbuf(*p_stream, NULL);

	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)
	{
	if (uid == 0) {
	return PSA_ERROR_INVALID_HANDLE;
	}

	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);
	MBEDTLS_PUT_UINT32_LE(data_length, header.size, 0);
	MBEDTLS_PUT_UINT32_LE(create_flags, header.flags, 0);

	psa_its_fill_filename(uid, filename);
	stream = fopen(PSA_ITS_STORAGE_TEMP, "wb");

	if (stream == NULL) {
	goto exit;
	}

	/* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
	mbedtls_setbuf(stream, NULL);

	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 */