components/service/crypto/client/psa/psa_mac.c

/*
 * Copyright (c) 2021, Arm Limited and Contributors. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include <string.h>
#include <stdlib.h>
#include <psa/crypto.h>
#include "psa_crypto_client.h"
#include <protocols/rpc/common/packed-c/status.h>
#include <protocols/service/crypto/packed-c/opcodes.h>
#include <protocols/service/crypto/packed-c/mac.h>
#include <common/tlv/tlv.h>

static psa_status_t common_mac_setup(psa_mac_operation_t *operation,
	psa_key_id_t key,
	psa_algorithm_t alg,
	uint32_t opcode)
{
	psa_status_t psa_status = PSA_ERROR_GENERIC_ERROR;
	struct ts_crypto_mac_setup_in req_msg;
	size_t req_len = sizeof(struct ts_crypto_mac_setup_in);

	req_msg.key_id = key;
	req_msg.alg = alg;

	rpc_call_handle call_handle;
	uint8_t *req_buf;

	call_handle = rpc_caller_begin(psa_crypto_client_instance.base.caller, &req_buf, req_len);

	if (call_handle) {

		uint8_t *resp_buf;
		size_t resp_len;
		int opstatus;

		memcpy(req_buf, &req_msg, req_len);

		psa_crypto_client_instance.base.rpc_status =
			rpc_caller_invoke(psa_crypto_client_instance.base.caller, call_handle,
				opcode, &opstatus, &resp_buf, &resp_len);

		if (psa_crypto_client_instance.base.rpc_status == TS_RPC_CALL_ACCEPTED) {

			psa_status = opstatus;

			if (psa_status == PSA_SUCCESS) {

				if (resp_len >= sizeof(struct ts_crypto_mac_setup_out)) {

					struct ts_crypto_mac_setup_out resp_msg;
					memcpy(&resp_msg, resp_buf, sizeof(struct ts_crypto_mac_setup_out));
					operation->handle = resp_msg.op_handle;
				}
				else {
					/* Failed to decode response message */
					psa_status = PSA_ERROR_GENERIC_ERROR;
				}
			}
		}

		rpc_caller_end(psa_crypto_client_instance.base.caller, call_handle);
	}

	return psa_status;
}

psa_status_t psa_mac_sign_setup(psa_mac_operation_t *operation,
	psa_key_id_t key,
	psa_algorithm_t alg)
{
	return common_mac_setup(operation, key, alg, TS_CRYPTO_OPCODE_MAC_SIGN_SETUP);
}

psa_status_t psa_mac_verify_setup(psa_mac_operation_t *operation,
	psa_key_id_t key,
	psa_algorithm_t alg)
{
	return common_mac_setup(operation, key, alg, TS_CRYPTO_OPCODE_MAC_VERIFY_SETUP);
}

psa_status_t psa_mac_update(psa_mac_operation_t *operation,
	const uint8_t *input,
	size_t input_length)
{
	psa_status_t psa_status = PSA_ERROR_GENERIC_ERROR;
	struct ts_crypto_mac_update_in req_msg;
	size_t req_fixed_len = sizeof(struct ts_crypto_mac_update_in);
	size_t req_len = req_fixed_len;

	req_msg.op_handle = operation->handle;

	/* Mandatory input data parameter */
	struct tlv_record data_record;
	data_record.tag = TS_CRYPTO_MAC_UPDATE_IN_TAG_DATA;
	data_record.length = input_length;
	data_record.value = input;
	req_len += tlv_required_space(data_record.length);

	rpc_call_handle call_handle;
	uint8_t *req_buf;

	call_handle = rpc_caller_begin(psa_crypto_client_instance.base.caller, &req_buf, req_len);

	if (call_handle) {

		uint8_t *resp_buf;
		size_t resp_len;
		int opstatus;
		struct tlv_iterator req_iter;

		memcpy(req_buf, &req_msg, req_fixed_len);

		tlv_iterator_begin(&req_iter, &req_buf[req_fixed_len], req_len - req_fixed_len);
		tlv_encode(&req_iter, &data_record);

		psa_crypto_client_instance.base.rpc_status =
			rpc_caller_invoke(psa_crypto_client_instance.base.caller, call_handle,
				TS_CRYPTO_OPCODE_MAC_UPDATE, &opstatus, &resp_buf, &resp_len);

		if (psa_crypto_client_instance.base.rpc_status == TS_RPC_CALL_ACCEPTED) psa_status = opstatus;

		rpc_caller_end(psa_crypto_client_instance.base.caller, call_handle);
	}

	return psa_status;
}

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 psa_status = PSA_ERROR_GENERIC_ERROR;
	struct ts_crypto_mac_sign_finish_in req_msg;
	size_t req_fixed_len = sizeof(struct ts_crypto_mac_sign_finish_in);
	size_t req_len = req_fixed_len;

	*mac_length = 0;
	req_msg.op_handle = operation->handle;

	rpc_call_handle call_handle;
	uint8_t *req_buf;

	call_handle = rpc_caller_begin(psa_crypto_client_instance.base.caller, &req_buf, req_len);

	if (call_handle) {

		uint8_t *resp_buf;
		size_t resp_len;
		int opstatus;

		memcpy(req_buf, &req_msg, req_fixed_len);

		psa_crypto_client_instance.base.rpc_status =
			rpc_caller_invoke(psa_crypto_client_instance.base.caller, call_handle,
				TS_CRYPTO_OPCODE_MAC_SIGN_FINISH, &opstatus, &resp_buf, &resp_len);

		if (psa_crypto_client_instance.base.rpc_status == TS_RPC_CALL_ACCEPTED) {

			psa_status = opstatus;

			if (psa_status == PSA_SUCCESS) {

				struct tlv_const_iterator resp_iter;
				struct tlv_record decoded_record;
				tlv_const_iterator_begin(&resp_iter, resp_buf, resp_len);

				if (tlv_find_decode(&resp_iter,
					TS_CRYPTO_MAC_SIGN_FINISH_OUT_TAG_MAC, &decoded_record)) {

					if (decoded_record.length <= mac_size) {

						memcpy(mac, decoded_record.value, decoded_record.length);
						*mac_length = decoded_record.length;
					}
					else {
						/* Provided buffer is too small */
						psa_status = PSA_ERROR_BUFFER_TOO_SMALL;
					}
				}
				else {
					/* Mandatory response parameter missing */
					psa_status = PSA_ERROR_GENERIC_ERROR;
				}
			}
		}

		rpc_caller_end(psa_crypto_client_instance.base.caller, call_handle);
	}

	return psa_status;
}

psa_status_t psa_mac_verify_finish(psa_mac_operation_t *operation,
	const uint8_t *mac,
	size_t mac_length)
{
	psa_status_t psa_status = PSA_ERROR_GENERIC_ERROR;
	struct ts_crypto_mac_verify_finish_in req_msg;
	size_t req_fixed_len = sizeof(struct ts_crypto_mac_verify_finish_in);
	size_t req_len = req_fixed_len;

	req_msg.op_handle = operation->handle;

	/* Mandatory input data parameter */
	struct tlv_record data_record;
	data_record.tag = TS_CRYPTO_MAC_VERIFY_FINISH_IN_TAG_MAC;
	data_record.length = mac_length;
	data_record.value = mac;
	req_len += tlv_required_space(data_record.length);

	rpc_call_handle call_handle;
	uint8_t *req_buf;

	call_handle = rpc_caller_begin(psa_crypto_client_instance.base.caller, &req_buf, req_len);

	if (call_handle) {

		uint8_t *resp_buf;
		size_t resp_len;
		int opstatus;
		struct tlv_iterator req_iter;

		memcpy(req_buf, &req_msg, req_fixed_len);

		tlv_iterator_begin(&req_iter, &req_buf[req_fixed_len], req_len - req_fixed_len);
		tlv_encode(&req_iter, &data_record);

		psa_crypto_client_instance.base.rpc_status =
			rpc_caller_invoke(psa_crypto_client_instance.base.caller, call_handle,
				TS_CRYPTO_OPCODE_MAC_VERIFY_FINISH, &opstatus, &resp_buf, &resp_len);

		if (psa_crypto_client_instance.base.rpc_status == TS_RPC_CALL_ACCEPTED) psa_status = opstatus;

		rpc_caller_end(psa_crypto_client_instance.base.caller, call_handle);
	}

	return psa_status;
}

psa_status_t psa_mac_abort(psa_mac_operation_t *operation)
{
	psa_status_t psa_status = PSA_ERROR_GENERIC_ERROR;
	struct ts_crypto_mac_abort_in req_msg;
	size_t req_fixed_len = sizeof(struct ts_crypto_mac_abort_in);
	size_t req_len = req_fixed_len;

	req_msg.op_handle = operation->handle;

	rpc_call_handle call_handle;
	uint8_t *req_buf;

	call_handle = rpc_caller_begin(psa_crypto_client_instance.base.caller, &req_buf, req_len);

	if (call_handle) {

		uint8_t *resp_buf;
		size_t resp_len;
		int opstatus;

		memcpy(req_buf, &req_msg, req_fixed_len);

		psa_crypto_client_instance.base.rpc_status =
			rpc_caller_invoke(psa_crypto_client_instance.base.caller, call_handle,
				TS_CRYPTO_OPCODE_MAC_ABORT, &opstatus, &resp_buf, &resp_len);

		if (psa_crypto_client_instance.base.rpc_status == TS_RPC_CALL_ACCEPTED) psa_status = opstatus;

		rpc_caller_end(psa_crypto_client_instance.base.caller, call_handle);
	}

	return psa_status;
}

static size_t max_mac_update_size(void)
{
	/* Returns the maximum number of bytes that may be
	 * carried as a parameter of the mac_update operation
	 * using the packed-c encoding.
	 */
	size_t payload_space = psa_crypto_client_instance.base.service_info.max_payload;
	size_t overhead = sizeof(struct ts_crypto_mac_update_in) + TLV_HDR_LEN;

	return (payload_space > overhead) ? payload_space - overhead : 0;
}

static psa_status_t multi_mac_update(psa_mac_operation_t *operation,
	const uint8_t *input,
	size_t input_length)
{
	psa_status_t psa_status = PSA_SUCCESS;
	size_t max_update_size = max_mac_update_size();
	size_t bytes_processed = 0;

	if (!max_update_size) {

		/* Don't know the max update size so assume that the entire
		 * input can be handled in a single update.  If this isn't
		 * true, the first mac update operation will fail safely.
		 */
		max_update_size = input_length;
	}

	while (bytes_processed < input_length) {

		size_t bytes_remaining = input_length - bytes_processed;
		size_t update_len = (bytes_remaining < max_update_size) ?
			bytes_remaining :
			max_update_size;

		psa_status = psa_mac_update(operation, &input[bytes_processed], update_len);

		if (psa_status != PSA_SUCCESS) {

			psa_mac_abort(operation);
			break;
		}

		bytes_processed += update_len;
	}

	return psa_status;
}

psa_status_t psa_mac_verify(psa_key_id_t key,
	psa_algorithm_t alg,
	const uint8_t *input,
	size_t input_length,
	const uint8_t *mac,
	size_t mac_length)
{
	psa_mac_operation_t operation = psa_mac_operation_init();
	psa_status_t psa_status = psa_mac_verify_setup(&operation, key, alg);

	if (psa_status == PSA_SUCCESS) {

		psa_status = multi_mac_update(&operation, input, input_length);
	}

	if (psa_status == PSA_SUCCESS) {

		psa_status = psa_mac_verify_finish(&operation, mac, mac_length);
	}

	return psa_status;
}

psa_status_t psa_mac_compute(psa_key_id_t key,
	psa_algorithm_t alg,
	const uint8_t *input,
	size_t input_length,
	uint8_t *mac,
	size_t mac_size,
	size_t *mac_length)
{
	psa_mac_operation_t operation = psa_mac_operation_init();
	psa_status_t psa_status = psa_mac_sign_setup(&operation, key, alg);

	if (psa_status == PSA_SUCCESS) {

		psa_status = multi_mac_update(&operation, input, input_length);
	}

	if (psa_status == PSA_SUCCESS) {

		psa_status = psa_mac_sign_finish(&operation, mac, mac_size, mac_length);
	}

	return psa_status;
}