간단하게 SHA256(sha2) 구하기

2011/12/14 - [프로그래밍/Let's Share it] - VC9.0에서 crypto++ library를 이용하여 SHA256(sha2) 구하기
과 다른 방식으로 sha2를 구하는 방법을 공유합니다.

물론, 제가 작성하기 보다는 다른 Open Source를 조합하여 만들었습니다.

참조한 Open Source는 lzma sdk(7z)로,
http://www.7-zip.org/sdk.html
에서 참조하였습니다.
Public domain license이기 때문에, 나름 수정/배포등이 용의하리라 봅니다.
물론, 본 post는 CCL license이고, 상업적 용도는 Off하였음을 알려드립니다.

해당 부분에 sha256을 구하는 코드가 있었습니다.
나름 참조하여 다음과 같이 "abc"에 대한 valid sha256 해쉬값을 구할 수 있으니,
참고하시기 바랍니다.

즉, 마지막 _main(...)을 참고하면 되는데,

Sha256_Init(&c);  Sha256_Update(&c, (Byte*)"abc", 3); Sha256_Final(&c, digest);

와 같이 함수 3개만으로 해결이 됩니다.

#include "stdafx.h"

#ifdef _LZMA_UINT32_IS_ULONG
typedef long Int32;
typedef unsigned long UInt32;
#else
typedef int Int32;
typedef unsigned int UInt32;
#endif

#if defined(_MSC_VER) || defined(__BORLANDC__)
typedef __int64 Int64;
typedef unsigned __int64 UInt64;
#define UINT64_CONST(n) n
#else
typedef long long int Int64;
typedef unsigned long long int UInt64;
#define UINT64_CONST(n) n ## ULL
#endif

#ifdef _MSC_VER

#include 
#define rotlFixed(x, n) _rotl((x), (n))
#define rotrFixed(x, n) _rotr((x), (n))

#else

#define rotlFixed(x, n) (((x) << (n)) | ((x) >> (32 - (n))))
#define rotrFixed(x, n) (((x) >> (n)) | ((x) << (32 - (n))))

#endif

#define SHA256_DIGEST_SIZE 32

typedef unsigned char Byte;

typedef struct
{
	UInt32 state[8];
	UInt64 count;
	Byte buffer[64];
} CSha256;

void Sha256_Init(CSha256 *p);
void Sha256_Update(CSha256 *p, const Byte *data, size_t size);
void Sha256_Final(CSha256 *p, Byte *digest);

void Sha256_Init(CSha256 *p)
{
	p->state[0] = 0x6a09e667;
	p->state[1] = 0xbb67ae85;
	p->state[2] = 0x3c6ef372;
	p->state[3] = 0xa54ff53a;
	p->state[4] = 0x510e527f;
	p->state[5] = 0x9b05688c;
	p->state[6] = 0x1f83d9ab;
	p->state[7] = 0x5be0cd19;
	p->count = 0;
}

#define S0(x) (rotrFixed(x, 2) ^ rotrFixed(x,13) ^ rotrFixed(x, 22))
#define S1(x) (rotrFixed(x, 6) ^ rotrFixed(x,11) ^ rotrFixed(x, 25))
#define s0(x) (rotrFixed(x, 7) ^ rotrFixed(x,18) ^ (x >> 3))
#define s1(x) (rotrFixed(x,17) ^ rotrFixed(x,19) ^ (x >> 10))

#define blk0(i) (W[i] = data[i])
#define blk2(i) (W[i&15] += s1(W[(i-2)&15]) + W[(i-7)&15] + s0(W[(i-15)&15]))

#define Ch(x,y,z) (z^(x&(y^z)))
#define Maj(x,y,z) ((x&y)|(z&(x|y)))

#define a(i) T[(0-(i))&7]
#define b(i) T[(1-(i))&7]
#define c(i) T[(2-(i))&7]
#define d(i) T[(3-(i))&7]
#define e(i) T[(4-(i))&7]
#define f(i) T[(5-(i))&7]
#define g(i) T[(6-(i))&7]
#define h(i) T[(7-(i))&7]


#ifdef _SHA256_UNROLL2

#define R(a,b,c,d,e,f,g,h, i) h += S1(e) + Ch(e,f,g) + K[i+j] + (j?blk2(i):blk0(i));\
	d += h; h += S0(a) + Maj(a, b, c)

#define RX_8(i) \
	R(a,b,c,d,e,f,g,h, i); \
	R(h,a,b,c,d,e,f,g, i+1); \
	R(g,h,a,b,c,d,e,f, i+2); \
	R(f,g,h,a,b,c,d,e, i+3); \
	R(e,f,g,h,a,b,c,d, i+4); \
	R(d,e,f,g,h,a,b,c, i+5); \
	R(c,d,e,f,g,h,a,b, i+6); \
	R(b,c,d,e,f,g,h,a, i+7)

#else

#define R(i) h(i) += S1(e(i)) + Ch(e(i),f(i),g(i)) + K[i+j] + (j?blk2(i):blk0(i));\
	d(i) += h(i); h(i) += S0(a(i)) + Maj(a(i), b(i), c(i))

#ifdef _SHA256_UNROLL

#define RX_8(i) R(i+0); R(i+1); R(i+2); R(i+3); R(i+4); R(i+5); R(i+6); R(i+7);

#endif

#endif

static const UInt32 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
};

static void Sha256_Transform(UInt32 *state, const UInt32 *data)
{
	UInt32 W[16];
	unsigned j;
#ifdef _SHA256_UNROLL2
	UInt32 a,b,c,d,e,f,g,h;
	a = state[0];
	b = state[1];
	c = state[2];
	d = state[3];
	e = state[4];
	f = state[5];
	g = state[6];
	h = state[7];
#else
	UInt32 T[8];
	for (j = 0; j < 8; j++)
		T[j] = state[j];
#endif

	for (j = 0; j < 64; j += 16)
	{
#if defined(_SHA256_UNROLL) || defined(_SHA256_UNROLL2)
		RX_8(0); RX_8(8);
#else
		unsigned i;
		for (i = 0; i < 16; i++) { R(i); }
#endif
	}

#ifdef _SHA256_UNROLL2
	state[0] += a;
	state[1] += b;
	state[2] += c;
	state[3] += d;
	state[4] += e;
	state[5] += f;
	state[6] += g;
	state[7] += h;
#else
	for (j = 0; j < 8; j++)
		state[j] += T[j];
#endif

	/* Wipe variables */
	/* memset(W, 0, sizeof(W)); */
	/* memset(T, 0, sizeof(T)); */
}

#undef S0
#undef S1
#undef s0
#undef s1

static void Sha256_WriteByteBlock(CSha256 *p)
{
	UInt32 data32[16];
	unsigned i;
	for (i = 0; i < 16; i++)
		data32[i] =
		((UInt32)(p->buffer[i * 4    ]) << 24) +
		((UInt32)(p->buffer[i * 4 + 1]) << 16) +
		((UInt32)(p->buffer[i * 4 + 2]) <<  8) +
		((UInt32)(p->buffer[i * 4 + 3]));
	Sha256_Transform(p->state, data32);
}

void Sha256_Update(CSha256 *p, const Byte *data, size_t size)
{
	UInt32 curBufferPos = (UInt32)p->count & 0x3F;
	while (size > 0)
	{
		p->buffer[curBufferPos++] = *data++;
		p->count++;
		size--;
		if (curBufferPos == 64)
		{
			curBufferPos = 0;
			Sha256_WriteByteBlock(p);
		}
	}
}

void Sha256_Final(CSha256 *p, Byte *digest)
{
	UInt64 lenInBits = (p->count << 3);
	UInt32 curBufferPos = (UInt32)p->count & 0x3F;
	unsigned i;
	p->buffer[curBufferPos++] = 0x80;
	while (curBufferPos != (64 - 8))
	{
		curBufferPos &= 0x3F;
		if (curBufferPos == 0)
			Sha256_WriteByteBlock(p);
		p->buffer[curBufferPos++] = 0;
	}
	for (i = 0; i < 8; i++)
	{
		p->buffer[curBufferPos++] = (Byte)(lenInBits >> 56);
		lenInBits <<= 8;
	}
	Sha256_WriteByteBlock(p);

	for (i = 0; i < 8; i++)
	{
		*digest++ = (Byte)(p->state[i] >> 24);
		*digest++ = (Byte)(p->state[i] >> 16);
		*digest++ = (Byte)(p->state[i] >> 8);
		*digest++ = (Byte)(p->state[i]);
	}
	Sha256_Init(p);
}

// http://www.nsrl.nist.gov/testdata/
int _tmain(int argc, _TCHAR* argv[])
{
	CSha256 c = {0,};
	Byte digest[SHA256_DIGEST_SIZE] = {0,};

	Sha256_Init(&c);
	Sha256_Update(&c, (Byte*)"abc", 3);
	Sha256_Final(&c, digest);

	// digest에 "abc"에 해당되는 sha256 값이 들어간다.

	return 0;
}