#include "pch.h"
#include "System/Security/Cryptography/HMACSHA256.h"
#include "System/ArgumentNullException.h"
#include <cstring>
namespace DotNetDupe {
namespace System {
namespace Security {
namespace Cryptography {
// --- SHA256 Helper Implementation ---
#define SHA2_SHFR(x, n) (x >> n)
#define SHA2_ROTR(x, n) ((x >> n) | (x << ((sizeof(x) << 3) - n)))
#define SHA2_CH(x, y, z) ((x & y) ^ (~x & z))
#define SHA2_MAJ(x, y, z) ((x & y) ^ (x & z) ^ (y & z))
#define SHA256_F1(x) (SHA2_ROTR(x, 2) ^ SHA2_ROTR(x, 13) ^ SHA2_ROTR(x, 22))
#define SHA256_F2(x) (SHA2_ROTR(x, 6) ^ SHA2_ROTR(x, 11) ^ SHA2_ROTR(x, 25))
#define SHA256_F3(x) (SHA2_ROTR(x, 7) ^ SHA2_ROTR(x, 18) ^ SHA2_SHFR(x, 3))
#define SHA256_F4(x) (SHA2_ROTR(x, 17) ^ SHA2_ROTR(x, 19) ^ SHA2_SHFR(x, 10))
#define SHA2_UNPACK32(x, str) \
{ \
*((str) + 3) = (unsigned char) ((x) ); \
*((str) + 2) = (unsigned char) ((x) >> 8); \
*((str) + 1) = (unsigned char) ((x) >> 16); \
*((str) + 0) = (unsigned char) ((x) >> 24); \
}
#define SHA2_PACK32(str, x) \
{ \
*(x) = ((unsigned int) *((str) + 3) ) \
| ((unsigned int) *((str) + 2) << 8) \
| ((unsigned int) *((str) + 1) << 16) \
| ((unsigned int) *((str) + 0) << 24);\
}
static const unsigned int sha256_k[64] = {
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
};
class SHA256Impl {
public:
void Init() {
h[0] = 0x6a09e667;
h[1] = 0xbb67ae85;
h[2] = 0x3c6ef372;
h[3] = 0xa54ff53a;
h[4] = 0x510e527f;
h[5] = 0x9b05688c;
h[6] = 0x1f83d9ab;
h[7] = 0x5be0cd19;
len = 0;
tot_len = 0;
}
void Transform(const unsigned char* message, unsigned int block_nb) {
unsigned int w[64];
unsigned int wv[8];
unsigned int t1, t2;
const unsigned char* sub_block;
for (unsigned int i = 0; i < block_nb; i++) {
sub_block = message + (i << 6);
for (unsigned int j = 0; j < 16; j++) {
SHA2_PACK32(&sub_block[j << 2], &w[j]);
}
for (unsigned int j = 16; j < 64; j++) {
w[j] = SHA256_F4(w[j - 2]) + w[j - 7] + SHA256_F3(w[j - 15]) + w[j - 16];
}
for (unsigned int j = 0; j < 8; j++) {
wv[j] = h[j];
}
for (unsigned int j = 0; j < 64; j++) {
t1 = wv[7] + SHA256_F2(wv[4]) + SHA2_CH(wv[4], wv[5], wv[6]) + sha256_k[j] + w[j];
t2 = SHA256_F1(wv[0]) + SHA2_MAJ(wv[0], wv[1], wv[2]);
wv[7] = wv[6];
wv[6] = wv[5];
wv[5] = wv[4];
wv[4] = wv[3] + t1;
wv[3] = wv[2];
wv[2] = wv[1];
wv[1] = wv[0];
wv[0] = t1 + t2;
}
for (unsigned int j = 0; j < 8; j++) {
h[j] += wv[j];
}
}
}
void Update(const unsigned char* message, unsigned int message_len) {
unsigned int tmp_len = 64 - len;
unsigned int rem_len = message_len < tmp_len ? message_len : tmp_len;
std::memcpy(&block[len], message, rem_len);
if (len + message_len < 64) {
len += message_len;
return;
}
Transform(block, 1);
unsigned int block_nb = (message_len - rem_len) >> 6;
Transform(message + rem_len, block_nb);
rem_len += (block_nb << 6);
len = message_len - rem_len;
std::memcpy(block, message + rem_len, len);
tot_len += (block_nb + 1) << 6;
}
void Final(unsigned char* digest) {
unsigned int block_nb = (64 - 9 < len) ? 2 : 1;
tot_len += len;
std::memset(&block[len], 0, 64 - len);
block[len] = 0x80;
if (block_nb == 2) {
Transform(block, 1);
std::memset(block, 0, 64);
}
SHA2_UNPACK32(tot_len << 3, &block[60]);
Transform(block, 1);
for (int i = 0; i < 8; i++) {
SHA2_UNPACK32(h[i], &digest[i << 2]);
}
}
private:
unsigned int tot_len;
unsigned int len;
unsigned char block[64];
unsigned int h[8];
};
// --- HMACSHA256 implementation ---
HMACSHA256::HMACSHA256() : m_key(0) {}
HMACSHA256::HMACSHA256(const Array<char>& key) : m_key(key) {}
Array<char> HMACSHA256::ComputeHash(const Array<char>& buffer) {
return ComputeHash(buffer, m_key);
}
static void PrepareHmacPads(const Array<char>& key, unsigned char* k_ipad, unsigned char* k_opad) {
unsigned char key_hashed[32];
int key_len = key.GetLength();
const unsigned char* key_data = reinterpret_cast<const unsigned char*>(key.GetData());
if (key_len > 64) {
SHA256Impl sha; sha.Init(); sha.Update(key_data, key_len); sha.Final(key_hashed);
key_data = key_hashed; key_len = 32;
}
std::memset(k_ipad, 0, 64); std::memset(k_opad, 0, 64);
if (key_len > 0) { std::memcpy(k_ipad, key_data, key_len); std::memcpy(k_opad, key_data, key_len); }
for (int i = 0; i < 64; i++) { k_ipad[i] ^= 0x36; k_opad[i] ^= 0x5c; }
}
static void ComputeHmacDigests(const unsigned char* k_ipad, const unsigned char* k_opad, const Array<char>& buffer, unsigned char* outer_digest) {
unsigned char inner_digest[32];
SHA256Impl sha_inner; sha_inner.Init(); sha_inner.Update(k_ipad, 64);
if (buffer.GetLength() > 0) sha_inner.Update(reinterpret_cast<const unsigned char*>(buffer.GetData()), buffer.GetLength());
sha_inner.Final(inner_digest);
SHA256Impl sha_outer; sha_outer.Init(); sha_outer.Update(k_opad, 64); sha_outer.Update(inner_digest, 32);
sha_outer.Final(outer_digest);
}
Array<char> HMACSHA256::ComputeHash(const Array<char>& buffer, const Array<char>& key) {
unsigned char k_ipad[64], k_opad[64], outer_digest[32];
PrepareHmacPads(key, k_ipad, k_opad);
ComputeHmacDigests(k_ipad, k_opad, buffer, outer_digest);
Array<char> result(32);
for (int i = 0; i < 32; i++) result[i] = static_cast<char>(outer_digest[i]);
return result;
}
}
}
}
}