/*
 * Copyright (c) 2014-2016 Alibaba Group. All rights reserved.
 * 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 <string.h>
#include "lite-log.h"
#include "utils_md5.h"
#include "utils_sha1.h"
#include "utils_hmac.h"

#define KEY_IOPAD_SIZE 64

#define MD5_DIGEST_SIZE 16
#define SHA1_DIGEST_SIZE 20

void utils_hmac_md5(const char *msg, int msg_len, char *digest, const char *key, int key_len)
{
    if((NULL == msg) || (NULL == digest) || (NULL == key)) {
        log_err("parameter is Null,failed!");
        return;
    }

    if(key_len > KEY_IOPAD_SIZE) {
        log_err("key_len > size(%d) of array",KEY_IOPAD_SIZE);
        return;
    }

    iot_md5_context context;
    unsigned char k_ipad[KEY_IOPAD_SIZE];    /* inner padding - key XORd with ipad  */
    unsigned char k_opad[KEY_IOPAD_SIZE];    /* outer padding - key XORd with opad */
    unsigned char out[MD5_DIGEST_SIZE];
    int i;

    /* start out by storing key in pads */
    memset(k_ipad, 0, sizeof(k_ipad));
    memset(k_opad, 0, sizeof(k_opad));
    memcpy(k_ipad, key, key_len);
    memcpy(k_opad, key, key_len);

    /* XOR key with ipad and opad values */
    for (i = 0; i < KEY_IOPAD_SIZE; i++) {
        k_ipad[i] ^= 0x36;
        k_opad[i] ^= 0x5c;
    }

    /* perform inner MD5 */
    utils_md5_init(&context);                                      /* init context for 1st pass */
    utils_md5_starts(&context);                                    /* setup context for 1st pass */
    utils_md5_update(&context, k_ipad, KEY_IOPAD_SIZE);            /* start with inner pad */
    utils_md5_update(&context, (unsigned char *) msg, msg_len);    /* then text of datagram */
    utils_md5_finish(&context, out);                               /* finish up 1st pass */

    /* perform outer MD5 */
    utils_md5_init(&context);                              /* init context for 2nd pass */
    utils_md5_starts(&context);                            /* setup context for 2nd pass */
    utils_md5_update(&context, k_opad, KEY_IOPAD_SIZE);    /* start with outer pad */
    utils_md5_update(&context, out, MD5_DIGEST_SIZE);      /* then results of 1st hash */
    utils_md5_finish(&context, out);                       /* finish up 2nd pass */

    for (i = 0; i < MD5_DIGEST_SIZE; ++i) {
        digest[i * 2] = utils_hb2hex(out[i] >> 4);
        digest[i * 2 + 1] = utils_hb2hex(out[i]);
    }
}

void utils_hmac_sha1(const char *msg, int msg_len, char *digest, const char *key, int key_len)
{
    if((NULL == msg) || (NULL == digest) || (NULL == key)) {
        log_err("parameter is Null,failed!");
        return;
    }

    if(key_len > KEY_IOPAD_SIZE) {
        log_err("key_len > size(%d) of array",KEY_IOPAD_SIZE);
        return;
    }

    iot_sha1_context context;
    unsigned char k_ipad[KEY_IOPAD_SIZE];    /* inner padding - key XORd with ipad  */
    unsigned char k_opad[KEY_IOPAD_SIZE];    /* outer padding - key XORd with opad */
    unsigned char out[SHA1_DIGEST_SIZE];
    int i;

    /* start out by storing key in pads */
    memset(k_ipad, 0, sizeof(k_ipad));
    memset(k_opad, 0, sizeof(k_opad));
    memcpy(k_ipad, key, key_len);
    memcpy(k_opad, key, key_len);

    /* XOR key with ipad and opad values */
    for (i = 0; i < KEY_IOPAD_SIZE; i++) {
        k_ipad[i] ^= 0x36;
        k_opad[i] ^= 0x5c;
    }

    /* perform inner SHA */
    utils_sha1_init(&context);                                      /* init context for 1st pass */
    utils_sha1_starts(&context);                                    /* setup context for 1st pass */
    utils_sha1_update(&context, k_ipad, KEY_IOPAD_SIZE);            /* start with inner pad */
    utils_sha1_update(&context, (unsigned char *) msg, msg_len);    /* then text of datagram */
    utils_sha1_finish(&context, out);                               /* finish up 1st pass */

    /* perform outer SHA */
    utils_sha1_init(&context);                              /* init context for 2nd pass */
    utils_sha1_starts(&context);                            /* setup context for 2nd pass */
    utils_sha1_update(&context, k_opad, KEY_IOPAD_SIZE);    /* start with outer pad */
    utils_sha1_update(&context, out, SHA1_DIGEST_SIZE);     /* then results of 1st hash */
    utils_sha1_finish(&context, out);                       /* finish up 2nd pass */

    for (i = 0; i < SHA1_DIGEST_SIZE; ++i) {
        digest[i * 2] = utils_hb2hex(out[i] >> 4);
        digest[i * 2 + 1] = utils_hb2hex(out[i]);
    }
}

