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#include "stdlib.h"
#include <stdio.h>
#include <string.h>
#define ROUND 16
int sBox[16] = {2, 10, 4, 12, 1, 3, 9, 14, 7, 11, 8, 6, 5, 0, 15, 13};
int rBox[16] = {13, 4, 0, 5, 2, 12, 11, 8, 10, 6, 1, 9, 3, 15, 7, 14};
void hex_to_bytes(const char *hex_str, unsigned char *bytes, size_t bytes_len) {
size_t hex_len = strlen(hex_str);
if (hex_len % 2 != 0 || hex_len / 2 > bytes_len) {
fprintf(stderr, "Invalid hex string length.\n");
return;
}
for (size_t i = 0; i < hex_len / 2; i++) {
sscanf(hex_str + 2 * i, "%2hhx", &bytes[i]);
}
}
void derive_round_key(unsigned int key, unsigned char *round_key, int length) {
unsigned int tmp = key;
for (int i = 0; i < length / 16; i++) {
memcpy(round_key + i * 16, &tmp, 4);
tmp++;
memcpy(round_key + i * 16 + 4, &tmp, 4);
tmp++;
memcpy(round_key + i * 16 + 8, &tmp, 4);
tmp++;
memcpy(round_key + i * 16 + 12, &tmp, 4);
tmp++;
}
}
int rb[256];
void reverseBits(unsigned char *state) {
unsigned char temp[16];
for (int i = 0; i < 16; i++) {
temp[15 - i] = rb[state[i]];
}
for (int i = 0; i < 16; i++) {
state[i] = temp[i];
}
}
void sBoxTransform(unsigned char *state) {
for (int i = 0; i < 16; i++) {
int lo = sBox[state[i] & 0xF];
int hi = sBox[state[i] >> 4];
state[i] = (hi << 4) | lo;
}
}
void rBoxTransform(unsigned char *state) {
for (int i = 0; i < 16; i++) {
int lo = rBox[state[i] & 0xF];
int hi = rBox[state[i] >> 4];
state[i] = (hi << 4) | lo;
}
}
void leftShiftBytes(unsigned char *state) {
unsigned char temp[16];
for (int i = 0; i < 16; i += 4) {
temp[i + 0] = state[i + 2] >> 5 | (state[i + 1] << 3);
temp[i + 1] = state[i + 3] >> 5 | (state[i + 2] << 3);
temp[i + 2] = state[i + 0] >> 5 | (state[i + 3] << 3);
temp[i + 3] = state[i + 1] >> 5 | (state[i + 0] << 3);
}
for (int i = 0; i < 16; i++) {
state[i] = temp[i];
}
}
void rightShiftBytes(unsigned char *state) {
unsigned char temp[16];
for (int i = 0; i < 16; i += 4) {
temp[i + 0] = (state[i + 2] << 5) | (state[i + 3] >> 3);
temp[i + 1] = (state[i + 0] >> 3) | (state[i + 3] << 5);
temp[i + 2] = (state[i + 0] << 5) | (state[i + 1] >> 3);
temp[i + 3] = (state[i + 1] << 5) | (state[i + 2] >> 3);
}
for (int i = 0; i < 16; i++) {
state[i] = temp[i];
}
}
void addRoundKey(unsigned char *state, unsigned char *roundKey,
unsigned int round) {
for (int i = 0; i < 16; i++)
state[i] ^= roundKey[i + round * 16];
}
void dump(unsigned char *d) {
for (int i = 0; i < 16; i++) {
printf("%02X", d[i]);
}
printf("\n");
}
void encrypt(unsigned char *password, unsigned int key,
unsigned char *ciphertext) {
unsigned char roundKeys[16 * ROUND] = {};
derive_round_key(key, roundKeys, 16 * ROUND);
unsigned char state[16];
memcpy(state, password, 16);
for (int round = 0; round < ROUND; round++) {
reverseBits(state);
sBoxTransform(state);
leftShiftBytes(state);
addRoundKey(state, roundKeys, round);
}
memcpy(ciphertext, state, 16);
}
void decrypt(unsigned char *ciphertext, unsigned int key,
unsigned char *password) {
unsigned char roundKeys[16 * ROUND] = {};
derive_round_key(key, roundKeys, 16 * ROUND);
unsigned char state[16];
memcpy(state, ciphertext, 16);
for (int round = 15; round >= 0; round--) {
addRoundKey(state, roundKeys, round);
rightShiftBytes(state);
rBoxTransform(state);
reverseBits(state);
}
memcpy(password, state, 16);
}
int main() {
for (int i = 0; i <= 255; i++) {
for (int u = 0; u < 8; u++)
rb[i] |= ((i >> u) & 1) << (7 - u);
}
unsigned char password[] =
"pwd:1234xxxxabcd";
unsigned int key = 0xF0FFFFFF;
unsigned char ciphertext[16];
unsigned char passback[17] = {0};
printf("Password: \n");
printf("%s\n", password);
encrypt(password, key, ciphertext);
decrypt(ciphertext, key, passback);
printf("%s\n", passback);
memcpy(ciphertext,
"\x99\xF2\x98\x0A\xAB\x4B\xE8\x64\x0D\x8F\x32\x21\x47\xCB\xA4\x09",
16);
unsigned int s = 0xf0000000;
unsigned int e = 0x00000000;
for (unsigned int key = s; key != e; key++) {
if ((key & ((1 << 14) - 1)) == 0) {
printf("key = %x (%.2lf%%)\n", key, (key - s) * 100. / (e - s));
}
decrypt(ciphertext, key, passback);
if (passback[0] == 'p' && passback[1] == 'w' && passback[2] == 'd' &&
passback[3] == ':') {
printf("%x\n", key);
printf("%16s\n", passback);
break;
}
}
}
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