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@menangen /main.c
Last active Sep 17, 2018

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newDES C implementation
//
// main.c
// newDES
//
// Created by menangen on 12.09.2018.
// Copyright © 2018 menangen. All rights reserved.
//
#include <stdio.h>
#import "newDES.h"
static
inline void
print_array (uint8_t * unsigned_array) {
for (int i = 0; i < 8; i++) {
printf(" %02x ", unsigned_array[i]);
}
printf("\n");
}
int main(int argc, const char * argv[]) {
// insert code here...
printf("Hello, newDES!\n");
uint8_t key [SIZE_USER_KEY] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E };
uint8_t encrypt_block [8] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07 };
print_array(encrypt_block);
encrypt_data(encrypt_block, key);
print_array(encrypt_block);
decrypt_data(encrypt_block, key);
print_array(encrypt_block);
return 0;
}
//
// newDES.c
// newDES
//
// Created by menangen on 13.09.2018.
// Copyright © 2018 menangen. All rights reserved.
//
#include "newDES.h"
u8 hash(u8 firstByte, u8 data, u8 keyByte, u8 exKeyByte) {
// printf("[0] data: %02x \n", data);
data -= 199; // printf("[1] data: %02x \n", data);
data ^= keyByte; // printf("[2] data: %02x \n", data);
data -= 71; // printf("[3] data: %02x \n", data);
data -= (data << 5); // printf("[4] data: %02x \n", data);
data ^= exKeyByte; // printf("[5] data: %02x \n", data);
data -= 151; // printf("[6] data: %02x \n", data);
data -= (data << 1); // printf("[7] data: %02x \n\n", data);
return data ^ firstByte;
};
void
encrypt_data (u8 * data, u8 *key)
{
u8 B0 = data[0], B1 = data[1], B2 = data[2], B3 = data[3], B4 =
data[4], B5 = data[5], B6 = data[6], B7 = data[7];
u8 i = 0, ex = 0;
while (1)
{
B4 = hash(B4, B0, key[i], ex);
if (++i == SIZE_USER_KEY)
{
i = 0;
ex = key[7];
}
B5 = hash(B5, B1, key[i], ex);
if (++i == SIZE_USER_KEY)
{
i = 0;
ex = key[8];
}
B6 = hash(B6, B2, key[i], ex);
if (++i == SIZE_USER_KEY)
{
i = 0;
ex = key[9];
}
B7 = hash(B7, B3, key[i], ex);
if (++i == SIZE_USER_KEY)
break;
B1 = hash(B1, B4, key[i++], ex);
B2 = hash(B2, B5, B4, 0);
B3 = hash(B3, B6, key[i++], ex);
B0 = hash(B0, B7, key[i++], ex);
}
data[0] = B0;
data[1] = B1;
data[2] = B2;
data[3] = B3;
data[4] = B4;
data[5] = B5;
data[6] = B6;
data[7] = B7;
}
void
decrypt_data (u8 * data, u8 *key)
{
u8
B0 = data[0], B1 = data[1],
B2 = data[2], B3 = data[3],
B4 = data[4], B5 = data[5],
B6 = data[6], B7 = data[7];
#define LAST_KEY_POSITION SIZE_USER_KEY - 1;
int8_t i = LAST_KEY_POSITION;
u8 ex = key[9];
while (1)
{
B7 = hash(B7, B3, key[i], ex);
if (--i < 0)
{
i = LAST_KEY_POSITION;
ex = key[8];
}
B6 = hash(B6, B2, key[i], ex);
if (--i < 0)
{
i = LAST_KEY_POSITION;
ex = key[7];
}
B5 = hash(B5, B1, key[i], ex);
if (--i < 0)
{
i = LAST_KEY_POSITION;
ex = 0;
}
B4 = hash(B4, B0, key[i], ex);
if (--i < 0)
break;
B0 = hash(B0, B7, key[i--], ex);
B3 = hash(B3, B6, key[i--], ex);
B2 = hash(B2, B5, B4, 0);
B1 = hash(B1, B4, key[i--], ex);
}
data[0] = B0;
data[1] = B1;
data[2] = B2;
data[3] = B3;
data[4] = B4;
data[5] = B5;
data[6] = B6;
data[7] = B7;
}
//
// newDES.h
// newDES
//
// Created by menangen on 13.09.2018.
// Copyright © 2018 menangen. All rights reserved.
//
#ifndef newDES_h
#define newDES_h
#import <string.h>
#endif /* newDES_h */
#define SIZE_USER_KEY 15
typedef uint8_t u8;
void encrypt_data (u8 *data, u8 *key);
void decrypt_data (u8 *data, u8 *key);
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