/* public domain sha256 implementation based on fips180-3 */

#include <ctype.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "../sha512.h"

static uint64_t ror(uint64_t n, int k) { return (n >> k) | (n << (64-k)); }
#define Ch(x,y,z)  (z ^ (x & (y ^ z)))
#define Maj(x,y,z) ((x & y) | (z & (x | y)))
#define S0(x)      (ror(x,28) ^ ror(x,34) ^ ror(x,39))
#define S1(x)      (ror(x,14) ^ ror(x,18) ^ ror(x,41))
#define R0(x)      (ror(x,1) ^ ror(x,8) ^ (x>>7))
#define R1(x)      (ror(x,19) ^ ror(x,61) ^ (x>>6))

static const uint64_t K[80] = {
0x428a2f98d728ae22ULL, 0x7137449123ef65cdULL, 0xb5c0fbcfec4d3b2fULL, 0xe9b5dba58189dbbcULL,
0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL, 0x923f82a4af194f9bULL, 0xab1c5ed5da6d8118ULL,
0xd807aa98a3030242ULL, 0x12835b0145706fbeULL, 0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL,
0x72be5d74f27b896fULL, 0x80deb1fe3b1696b1ULL, 0x9bdc06a725c71235ULL, 0xc19bf174cf692694ULL,
0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL, 0x0fc19dc68b8cd5b5ULL, 0x240ca1cc77ac9c65ULL,
0x2de92c6f592b0275ULL, 0x4a7484aa6ea6e483ULL, 0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL,
0x983e5152ee66dfabULL, 0xa831c66d2db43210ULL, 0xb00327c898fb213fULL, 0xbf597fc7beef0ee4ULL,
0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL, 0x06ca6351e003826fULL, 0x142929670a0e6e70ULL,
0x27b70a8546d22ffcULL, 0x2e1b21385c26c926ULL, 0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL,
0x650a73548baf63deULL, 0x766a0abb3c77b2a8ULL, 0x81c2c92e47edaee6ULL, 0x92722c851482353bULL,
0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL, 0xc24b8b70d0f89791ULL, 0xc76c51a30654be30ULL,
0xd192e819d6ef5218ULL, 0xd69906245565a910ULL, 0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL,
0x19a4c116b8d2d0c8ULL, 0x1e376c085141ab53ULL, 0x2748774cdf8eeb99ULL, 0x34b0bcb5e19b48a8ULL,
0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL, 0x5b9cca4f7763e373ULL, 0x682e6ff3d6b2b8a3ULL,
0x748f82ee5defb2fcULL, 0x78a5636f43172f60ULL, 0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL,
0x90befffa23631e28ULL, 0xa4506cebde82bde9ULL, 0xbef9a3f7b2c67915ULL, 0xc67178f2e372532bULL,
0xca273eceea26619cULL, 0xd186b8c721c0c207ULL, 0xeada7dd6cde0eb1eULL, 0xf57d4f7fee6ed178ULL,
0x06f067aa72176fbaULL, 0x0a637dc5a2c898a6ULL, 0x113f9804bef90daeULL, 0x1b710b35131c471bULL,
0x28db77f523047d84ULL, 0x32caab7b40c72493ULL, 0x3c9ebe0a15c9bebcULL, 0x431d67c49c100d4cULL,
0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL, 0x5fcb6fab3ad6faecULL, 0x6c44198c4a475817ULL
};

static void
processblock(struct sha512 *s, const uint8_t *buf)
{
	uint64_t W[80], t1, t2, a, b, c, d, e, f, g, h;
	int i;

	for (i = 0; i < 16; i++) {
		W[i] = (uint64_t)buf[8*i]<<56;
		W[i] |= (uint64_t)buf[8*i+1]<<48;
		W[i] |= (uint64_t)buf[8*i+2]<<40;
		W[i] |= (uint64_t)buf[8*i+3]<<32;
		W[i] |= (uint64_t)buf[8*i+4]<<24;
		W[i] |= (uint64_t)buf[8*i+5]<<16;
		W[i] |= (uint64_t)buf[8*i+6]<<8;
		W[i] |= buf[8*i+7];
	}
	for (; i < 80; i++)
		W[i] = R1(W[i-2]) + W[i-7] + R0(W[i-15]) + W[i-16];
	a = s->h[0];
	b = s->h[1];
	c = s->h[2];
	d = s->h[3];
	e = s->h[4];
	f = s->h[5];
	g = s->h[6];
	h = s->h[7];
	for (i = 0; i < 80; i++) {
		t1 = h + S1(e) + Ch(e,f,g) + K[i] + W[i];
		t2 = S0(a) + Maj(a,b,c);
		h = g;
		g = f;
		f = e;
		e = d + t1;
		d = c;
		c = b;
		b = a;
		a = t1 + t2;
	}
	s->h[0] += a;
	s->h[1] += b;
	s->h[2] += c;
	s->h[3] += d;
	s->h[4] += e;
	s->h[5] += f;
	s->h[6] += g;
	s->h[7] += h;
}

static void
pad(struct sha512 *s)
{
	unsigned r = s->len % 128;

	s->buf[r++] = 0x80;
	if (r > 112) {
		memset(s->buf + r, 0, 128 - r);
		r = 0;
		processblock(s, s->buf);
	}
	memset(s->buf + r, 0, 120 - r);
	s->len *= 8;
	s->buf[120] = s->len >> 56;
	s->buf[121] = s->len >> 48;
	s->buf[122] = s->len >> 40;
	s->buf[123] = s->len >> 32;
	s->buf[124] = s->len >> 24;
	s->buf[125] = s->len >> 16;
	s->buf[126] = s->len >> 8;
	s->buf[127] = s->len;
	processblock(s, s->buf);
}

void
sha512_init(void *ctx)
{
	struct sha512 *s = ctx;
	s->len = 0;
	s->h[0] = 0x6a09e667f3bcc908ULL;
	s->h[1] = 0xbb67ae8584caa73bULL;
	s->h[2] = 0x3c6ef372fe94f82bULL;
	s->h[3] = 0xa54ff53a5f1d36f1ULL;
	s->h[4] = 0x510e527fade682d1ULL;
	s->h[5] = 0x9b05688c2b3e6c1fULL;
	s->h[6] = 0x1f83d9abfb41bd6bULL;
	s->h[7] = 0x5be0cd19137e2179ULL;
}

void
sha512_sum_n(void *ctx, uint8_t *md, int n)
{
	struct sha512 *s = ctx;
	int i;

	pad(s);
	for (i = 0; i < n; i++) {
		md[8*i] = s->h[i] >> 56;
		md[8*i+1] = s->h[i] >> 48;
		md[8*i+2] = s->h[i] >> 40;
		md[8*i+3] = s->h[i] >> 32;
		md[8*i+4] = s->h[i] >> 24;
		md[8*i+5] = s->h[i] >> 16;
		md[8*i+6] = s->h[i] >> 8;
		md[8*i+7] = s->h[i];
	}
}

void
sha512_sum(void *ctx, uint8_t md[SHA512_DIGEST_LENGTH])
{
	sha512_sum_n(ctx, md, 8);
}

void
sha512_update(void *ctx, const void *m, unsigned long len)
{
	struct sha512 *s = ctx;
	const uint8_t *p = m;
	unsigned r = s->len % 128;

	s->len += len;
	if (r) {
		if (len < 128 - r) {
			memcpy(s->buf + r, p, len);
			return;
		}
		memcpy(s->buf + r, p, 128 - r);
		len -= 128 - r;
		p += 128 - r;
		processblock(s, s->buf);
	}
	for (; len >= 128; len -= 128, p += 128)
		processblock(s, p);
	memcpy(s->buf, p, len);
}