Cybersecurity-Projects/PROJECTS/intermediate/binary-analysis-tool/test-specimens/crypto_tool.c

155 lines
4.4 KiB
C

// ©AngelaMos | 2026
// crypto_tool.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
static const uint32_t K[] = {
0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2,
};
static uint32_t rotr(uint32_t x, int n) {
return (x >> n) | (x << (32 - n));
}
static void sha256_transform(uint32_t state[8], const uint8_t block[64]) {
uint32_t w[64];
for (int i = 0; i < 16; i++) {
w[i] = ((uint32_t)block[i*4] << 24) |
((uint32_t)block[i*4+1] << 16) |
((uint32_t)block[i*4+2] << 8) |
((uint32_t)block[i*4+3]);
}
for (int i = 16; i < 64; i++) {
uint32_t s0 = rotr(w[i-15], 7) ^ rotr(w[i-15], 18) ^ (w[i-15] >> 3);
uint32_t s1 = rotr(w[i-2], 17) ^ rotr(w[i-2], 19) ^ (w[i-2] >> 10);
w[i] = w[i-16] + s0 + w[i-7] + s1;
}
uint32_t a = state[0], b = state[1], c = state[2], d = state[3];
uint32_t e = state[4], f = state[5], g = state[6], h = state[7];
for (int i = 0; i < 64; i++) {
uint32_t S1 = rotr(e, 6) ^ rotr(e, 11) ^ rotr(e, 25);
uint32_t ch = (e & f) ^ (~e & g);
uint32_t t1 = h + S1 + ch + K[i] + w[i];
uint32_t S0 = rotr(a, 2) ^ rotr(a, 13) ^ rotr(a, 22);
uint32_t maj = (a & b) ^ (a & c) ^ (b & c);
uint32_t t2 = S0 + maj;
h = g; g = f; f = e; e = d + t1;
d = c; c = b; b = a; a = t1 + t2;
}
state[0] += a; state[1] += b; state[2] += c; state[3] += d;
state[4] += e; state[5] += f; state[6] += g; state[7] += h;
}
static void sha256(const uint8_t *data, size_t len, uint8_t hash[32]) {
uint32_t state[8] = {
0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19,
};
uint8_t block[64];
size_t i;
for (i = 0; i + 64 <= len; i += 64) {
sha256_transform(state, data + i);
}
size_t rem = len - i;
memset(block, 0, 64);
memcpy(block, data + i, rem);
block[rem] = 0x80;
if (rem >= 56) {
sha256_transform(state, block);
memset(block, 0, 64);
}
uint64_t bits = (uint64_t)len * 8;
for (int j = 0; j < 8; j++) {
block[63 - j] = (uint8_t)(bits >> (j * 8));
}
sha256_transform(state, block);
for (int j = 0; j < 8; j++) {
hash[j*4] = (uint8_t)(state[j] >> 24);
hash[j*4+1] = (uint8_t)(state[j] >> 16);
hash[j*4+2] = (uint8_t)(state[j] >> 8);
hash[j*4+3] = (uint8_t)(state[j]);
}
}
static void xor_encrypt(uint8_t *data, size_t len, const uint8_t *key, size_t klen) {
for (size_t i = 0; i < len; i++) {
data[i] ^= key[i % klen];
}
}
int main(int argc, char *argv[]) {
if (argc < 2) {
fprintf(stderr, "Usage: %s <file>\n", argv[0]);
return 1;
}
FILE *fp = fopen(argv[1], "rb");
if (!fp) {
perror("fopen");
return 1;
}
fseek(fp, 0, SEEK_END);
long fsize = ftell(fp);
rewind(fp);
uint8_t *buf = malloc(fsize);
if (!buf) {
fclose(fp);
return 1;
}
fread(buf, 1, fsize, fp);
fclose(fp);
uint8_t hash[32];
sha256(buf, fsize, hash);
printf("SHA-256: ");
for (int i = 0; i < 32; i++) {
printf("%02x", hash[i]);
}
printf("\n");
uint8_t key[] = {0xDE, 0xAD, 0xBE, 0xEF, 0xCA, 0xFE, 0xBA, 0xBE};
xor_encrypt(buf, fsize, key, sizeof(key));
printf("XOR-encrypted %ld bytes with 8-byte key.\n", fsize);
uint8_t enc_hash[32];
sha256(buf, fsize, enc_hash);
printf("ENC-256: ");
for (int i = 0; i < 32; i++) {
printf("%02x", enc_hash[i]);
}
printf("\n");
free(buf);
return 0;
}