Function sha_compress

src/base/hash_libtomcrypt.cpp:64–108

static u32 Gamma1(u32 x) { return Rot(x, 17) ^ Rot(x, 19) ^ Sh(x, 10); }

static void sha_compress(sha256_state *md, const unsigned char *buf)
{
	u32 S[8], W[64], t;
	int i;

	// Copy state into S
	for(i = 0; i < 8; i++)
		S[i] = md->state[i];

	// Copy the state into 512-bits into W[0..15]
	for(i = 0; i < 16; i++)
		W[i] = load32(buf + (4 * i));

	// Fill W[16..63]
	for(i = 16; i < 64; i++)
		W[i] = Gamma1(W[i - 2]) + W[i - 7] + Gamma0(W[i - 15]) + W[i - 16];

// Compress
#define RND(a, b, c, d, e, f, g, h, i) \
	do \
	{ \
		u32 t0 = (h) + Sigma1(e) + Ch(e, f, g) + K[i] + W[i]; \
		u32 t1 = Sigma0(a) + Maj(a, b, c); \
		(d) += t0; \
		(h) = t0 + t1; \
	} while(0)

	for(i = 0; i < 64; ++i)
	{
		RND(S[0], S[1], S[2], S[3], S[4], S[5], S[6], S[7], i);
		t = S[7];
		S[7] = S[6];
		S[6] = S[5];
		S[5] = S[4];
		S[4] = S[3];
		S[3] = S[2];
		S[2] = S[1];
		S[1] = S[0];
		S[0] = t;
	}

	// Feedback
	for(i = 0; i < 8; i++)
		md->state[i] = md->state[i] + S[i];
}

// Public interface