Function SHA1ProcessMessageBlock

Source/sha.cpp:74–136

}

void SHA1ProcessMessageBlock(SHA1Context *context)
{
	DWORD i, temp;
	DWORD W[80];
	DWORD A, B, C, D, E;

	DWORD *buf = (DWORD *)context->buffer;
	for (i = 0; i < 16; i++)
		W[i] = SwapLE32(buf[i]);


	for (i = 16; i < 80; i++) {
		W[i] = W[i - 16] ^ W[i - 14] ^ W[i - 8] ^ W[i - 3];
	}

	A = context->state[0];
	B = context->state[1];
	C = context->state[2];
	D = context->state[3];
	E = context->state[4];

	for (i = 0; i < 20; i++) {
		temp = SHA1CircularShift(5, A) + ((B & C) | ((~B) & D)) + E + W[i] + 0x5A827999;
		E = D;
		D = C;
		C = SHA1CircularShift(30, B);
		B = A;
		A = temp;
	}

	for (i = 20; i < 40; i++) {
		temp = SHA1CircularShift(5, A) + (B ^ C ^ D) + E + W[i] + 0x6ED9EBA1;
		E = D;
		D = C;
		C = SHA1CircularShift(30, B);
		B = A;
		A = temp;
	}

	for (i = 40; i < 60; i++) {
		temp = SHA1CircularShift(5, A) + ((B & C) | (B & D) | (C & D)) + E + W[i] + 0x8F1BBCDC;
		E = D;
		D = C;
		C = SHA1CircularShift(30, B);
		B = A;
		A = temp;
	}

	for (i = 60; i < 80; i++) {
		temp = SHA1CircularShift(5, A) + (B ^ C ^ D) + E + W[i] + 0xCA62C1D6;
		E = D;
		D = C;
		C = SHA1CircularShift(30, B);
		B = A;
		A = temp;
	}

	context->state[0] += A;