mbed-os/source/Security/TLS/tls_ccm_crypt.c

102 lines
3.0 KiB
C

/*
* Copyright (c) 2017-2018, Pelion and affiliates.
* 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 "nsconfig.h"
#include "ns_types.h"
#ifdef PANA
#include "ns_trace.h"
#include "string.h"
#include "ccmLIB.h"
#include "ns_trace.h"
#include "common_functions.h"
#define CLIENT_WRITE_KEY 0
#define SERVER_WRITE_KEY 16
#define CLIENT_IV 32
#define SERVER_IV 36
#define TRACE_GROUP "cryp"
#define TLS_1_2_VER 0x0303
static bool tls_ccm_init(ccm_globals_t *ccm_ptr, const uint8_t *key_expansion, const uint8_t *nonce, bool server, uint8_t crypt_process)
{
const uint8_t *key, *iv_ptr;
if (server) {
key = key_expansion + SERVER_WRITE_KEY;
iv_ptr = key_expansion + SERVER_IV;
} else {
key = key_expansion + CLIENT_WRITE_KEY;
iv_ptr = key_expansion + CLIENT_IV;
}
if (!ccm_sec_init(ccm_ptr, AES_SECURITY_LEVEL_ENC_MIC64, key, crypt_process, 3)) {
return false;
}
memcpy(ccm_ptr->exp_nonce, iv_ptr, 4);
memcpy(&ccm_ptr->exp_nonce[4], nonce, 8);
return true;
}
static void tls_set_adata(ccm_globals_t *ccm_ptr, uint8_t *a_data, const uint8_t *nonce, uint8_t type)
{
ccm_ptr->adata_len = 13;
ccm_ptr->adata_ptr = a_data;
memcpy(a_data, nonce, 8);
a_data += 8;
*a_data++ = type;
a_data = common_write_16_bit(TLS_1_2_VER, a_data);
common_write_16_bit(ccm_ptr->data_len, a_data);
}
int8_t tls_ccm_data_encrypt(uint8_t *data_ptr, uint16_t data_length, const uint8_t *key_expansion, const uint8_t *nonce, uint8_t type, bool server)
{
ccm_globals_t ccm_ptr;
if (!tls_ccm_init(&ccm_ptr, key_expansion, nonce, server, AES_CCM_ENCRYPT)) {
return -1;
}
uint8_t adata[13];
ccm_ptr.data_len = data_length;
ccm_ptr.data_ptr = data_ptr;
ccm_ptr.mic = (ccm_ptr.data_ptr + ccm_ptr.data_len);
tls_set_adata(&ccm_ptr, adata, nonce, type);
return ccm_process_run(&ccm_ptr);
}
int8_t tls_ccm_data_decrypt(uint8_t *data_ptr, uint16_t data_length, const uint8_t *key_expansion, uint8_t type, bool server)
{
if (data_length <= 16) {
return -1;
}
ccm_globals_t ccm_ptr;
if (!tls_ccm_init(&ccm_ptr, key_expansion, data_ptr, server, AES_CCM_DECRYPT)) {
return -1;
}
uint8_t adata[13];
ccm_ptr.data_len = data_length - 16;
tls_set_adata(&ccm_ptr, adata, data_ptr, type);
ccm_ptr.data_ptr = data_ptr + 8;
ccm_ptr.mic = (ccm_ptr.data_ptr + ccm_ptr.data_len);
return ccm_process_run(&ccm_ptr);
}
#endif