secure_storage/ta/secure_storage_ta.c

/*
 * Copyright (c) 2017, Linaro Limited
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <inttypes.h>
#include <secure_storage_ta.h>
#include <tee_internal_api.h>
#include <tee_internal_api_extensions.h>

static TEE_Result delete_object(uint32_t param_types, TEE_Param params[4])
{
	const uint32_t exp_param_types =
		TEE_PARAM_TYPES(TEE_PARAM_TYPE_MEMREF_INPUT,
				TEE_PARAM_TYPE_NONE,
				TEE_PARAM_TYPE_NONE,
				TEE_PARAM_TYPE_NONE);
	TEE_ObjectHandle object;
	TEE_Result res;
	char *obj_id;
	size_t obj_id_sz;

	/*
	 * Safely get the invocation parameters
	 */
	if (param_types != exp_param_types)
		return TEE_ERROR_BAD_PARAMETERS;

	obj_id_sz = params[0].memref.size;
	obj_id = TEE_Malloc(obj_id_sz, 0);
	if (!obj_id)
		return TEE_ERROR_OUT_OF_MEMORY;

	TEE_MemMove(obj_id, params[0].memref.buffer, obj_id_sz);

	/*
	 * Check object exists and delete it
	 */
	res = TEE_OpenPersistentObject(TEE_STORAGE_PRIVATE,
					obj_id, obj_id_sz,
					TEE_DATA_FLAG_ACCESS_READ |
					TEE_DATA_FLAG_ACCESS_WRITE_META, /* we must be allowed to delete it */
					&object);
	if (res != TEE_SUCCESS) {
		EMSG("Failed to open persistent object, res=0x%08x", res);
		TEE_Free(obj_id);
		return res;
	}

	TEE_CloseAndDeletePersistentObject1(object);
	TEE_Free(obj_id);

	return res;
}

static TEE_Result create_raw_object(uint32_t param_types, TEE_Param params[4])
{
	const uint32_t exp_param_types =
		TEE_PARAM_TYPES(TEE_PARAM_TYPE_MEMREF_INPUT,
				TEE_PARAM_TYPE_MEMREF_INPUT,
				TEE_PARAM_TYPE_NONE,
				TEE_PARAM_TYPE_NONE);
	TEE_ObjectHandle object;
	TEE_Result res;
	char *obj_id;
	size_t obj_id_sz;
	char *data;
	size_t data_sz;
	uint32_t obj_data_flag;

	/*
	 * Safely get the invocation parameters
	 */
	if (param_types != exp_param_types)
		return TEE_ERROR_BAD_PARAMETERS;

	obj_id_sz = params[0].memref.size;
	obj_id = TEE_Malloc(obj_id_sz, 0);
	if (!obj_id)
		return TEE_ERROR_OUT_OF_MEMORY;

	TEE_MemMove(obj_id, params[0].memref.buffer, obj_id_sz);

	data = (char *)params[1].memref.buffer;
	data_sz = params[1].memref.size;

	/*
	 * Create object in secure storage and fill with data
	 */
	obj_data_flag = TEE_DATA_FLAG_ACCESS_READ |		/* we can later read the oject */
			TEE_DATA_FLAG_ACCESS_WRITE |		/* we can later write into the object */
			TEE_DATA_FLAG_ACCESS_WRITE_META |	/* we can later destroy or rename the object */
			TEE_DATA_FLAG_OVERWRITE;		/* destroy existing object of same ID */

	res = TEE_CreatePersistentObject(TEE_STORAGE_PRIVATE,
					obj_id, obj_id_sz,
					obj_data_flag,
					TEE_HANDLE_NULL,
					NULL, 0,		/* we may not fill it right now */
					&object);
	if (res != TEE_SUCCESS) {
		EMSG("TEE_CreatePersistentObject failed 0x%08x", res);
		TEE_Free(obj_id);
		return res;
	}

	res = TEE_WriteObjectData(object, data, data_sz);
	if (res != TEE_SUCCESS) {
		EMSG("TEE_WriteObjectData failed 0x%08x", res);
		TEE_CloseAndDeletePersistentObject1(object);
	} else {
		TEE_CloseObject(object);
	}
	TEE_Free(obj_id);
	return res;
}

static TEE_Result read_raw_object(uint32_t param_types, TEE_Param params[4])
{
	const uint32_t exp_param_types =
		TEE_PARAM_TYPES(TEE_PARAM_TYPE_MEMREF_INPUT,
				TEE_PARAM_TYPE_MEMREF_OUTPUT,
				TEE_PARAM_TYPE_NONE,
				TEE_PARAM_TYPE_NONE);
	TEE_ObjectHandle object;
	TEE_ObjectInfo object_info;
	TEE_Result res;
	uint32_t read_bytes;
	char *obj_id;
	size_t obj_id_sz;
	char *data;
	size_t data_sz;

	/*
	 * Safely get the invocation parameters
	 */
	if (param_types != exp_param_types)
		return TEE_ERROR_BAD_PARAMETERS;

	obj_id_sz = params[0].memref.size;
	obj_id = TEE_Malloc(obj_id_sz, 0);
	if (!obj_id)
		return TEE_ERROR_OUT_OF_MEMORY;

	TEE_MemMove(obj_id, params[0].memref.buffer, obj_id_sz);

	data = (char *)params[1].memref.buffer;
	data_sz = params[1].memref.size;

	/*
	 * Check the object exist and can be dumped into output buffer
	 * then dump it.
	 */
	res = TEE_OpenPersistentObject(TEE_STORAGE_PRIVATE,
					obj_id, obj_id_sz,
					TEE_DATA_FLAG_ACCESS_READ |
					TEE_DATA_FLAG_SHARE_READ,
					&object);
	if (res != TEE_SUCCESS) {
		EMSG("Failed to open persistent object, res=0x%08x", res);
		TEE_Free(obj_id);
		return res;
	}

	res = TEE_GetObjectInfo1(object, &object_info);
	if (res != TEE_SUCCESS) {
		EMSG("Failed to create persistent object, res=0x%08x", res);
		goto exit;
	}

	if (object_info.dataSize > data_sz) {
		/*
		 * Provided buffer is too short.
		 * Return the expected size together with status "short buffer"
		 */
		params[1].memref.size = object_info.dataSize;
		res = TEE_ERROR_SHORT_BUFFER;
		goto exit;
	}

	res = TEE_ReadObjectData(object, data, object_info.dataSize,
				 &read_bytes);
	if (res != TEE_SUCCESS || read_bytes != object_info.dataSize) {
		EMSG("TEE_ReadObjectData failed 0x%08x, read %" PRIu32 " over %u",
				res, read_bytes, object_info.dataSize);
		goto exit;
	}

	/* Return the number of byte effectively filled */
	params[1].memref.size = read_bytes;
exit:
	TEE_CloseObject(object);
	TEE_Free(obj_id);
	return res;
}

TEE_Result TA_CreateEntryPoint(void)
{
	/* Nothing to do */
	return TEE_SUCCESS;
}

void TA_DestroyEntryPoint(void)
{
	/* Nothing to do */
}

TEE_Result TA_OpenSessionEntryPoint(uint32_t __unused param_types,
				    TEE_Param __unused params[4],
				    void __unused **session)
{
	/* Nothing to do */
	return TEE_SUCCESS;
}

void TA_CloseSessionEntryPoint(void __unused *session)
{
	/* Nothing to do */
}

TEE_Result TA_InvokeCommandEntryPoint(void __unused *session,
				      uint32_t command,
				      uint32_t param_types,
				      TEE_Param params[4])
{
	switch (command) {
	case TA_SECURE_STORAGE_CMD_WRITE_RAW:
		return create_raw_object(param_types, params);
	case TA_SECURE_STORAGE_CMD_READ_RAW:
		return read_raw_object(param_types, params);
	case TA_SECURE_STORAGE_CMD_DELETE:
		return delete_object(param_types, params);
	default:
		EMSG("Command ID 0x%x is not supported", command);
		return TEE_ERROR_NOT_SUPPORTED;
	}
}