// Copyright (c) 2014-2018, The Monero Project
//
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/*
 * The blake256_* and blake224_* functions are largely copied from
 * blake256_light.c and blake224_light.c from the BLAKE website:
 *
 *     http://131002.net/blake/
 *
 * The hmac_* functions implement HMAC-BLAKE-256 and HMAC-BLAKE-224.
 * HMAC is specified by RFC 2104.
 */

#include <string.h>
#include <stdio.h>
#include <stdint.h>
#include "blake256.h"

#define U8TO32(p) \
    (((uint32_t)((p)[0]) << 24) | ((uint32_t)((p)[1]) << 16) |    \
     ((uint32_t)((p)[2]) <<  8) | ((uint32_t)((p)[3])      ))
#define U32TO8(p, v) \
    (p)[0] = (uint8_t)((v) >> 24); (p)[1] = (uint8_t)((v) >> 16); \
    (p)[2] = (uint8_t)((v) >>  8); (p)[3] = (uint8_t)((v)      );

const uint8_t sigma[][16] = {
	{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15},
	{14, 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3},
	{11, 8, 12, 0, 5, 2, 15, 13, 10, 14, 3, 6, 7, 1, 9, 4},
	{7, 9, 3, 1, 13, 12, 11, 14, 2, 6, 5, 10, 4, 0, 15, 8},
	{9, 0, 5, 7, 2, 4, 10, 15, 14, 1, 11, 12, 6, 8, 3, 13},
	{2, 12, 6, 10, 0, 11, 8, 3, 4, 13, 7, 5, 15, 14, 1, 9},
	{12, 5, 1, 15, 14, 13, 4, 10, 0, 7, 6, 3, 9, 2, 8, 11},
	{13, 11, 7, 14, 12, 1, 3, 9, 5, 0, 15, 4, 8, 6, 2, 10},
	{6, 15, 14, 9, 11, 3, 0, 8, 12, 2, 13, 7, 1, 4, 10, 5},
	{10, 2, 8, 4, 7, 6, 1, 5, 15, 11, 9, 14, 3, 12, 13, 0},
	{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15},
	{14, 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3},
	{11, 8, 12, 0, 5, 2, 15, 13, 10, 14, 3, 6, 7, 1, 9, 4},
	{7, 9, 3, 1, 13, 12, 11, 14, 2, 6, 5, 10, 4, 0, 15, 8}
};

const uint32_t cst[16] = {
	0x243F6A88, 0x85A308D3, 0x13198A2E, 0x03707344,
	0xA4093822, 0x299F31D0, 0x082EFA98, 0xEC4E6C89,
	0x452821E6, 0x38D01377, 0xBE5466CF, 0x34E90C6C,
	0xC0AC29B7, 0xC97C50DD, 0x3F84D5B5, 0xB5470917
};

static const uint8_t padding[] = {
	0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	    0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	    0, 0, 0, 0, 0, 0, 0, 0
};


void blake256_compress(state * S, const uint8_t * block)
{
	uint32_t v[16], m[16], i;

#define ROT(x,n) (((x)<<(32-n))|((x)>>(n)))
#define G(a,b,c,d,e)                                      \
    v[a] += (m[sigma[i][e]] ^ cst[sigma[i][e+1]]) + v[b]; \
    v[d] = ROT(v[d] ^ v[a],16);                           \
    v[c] += v[d];                                         \
    v[b] = ROT(v[b] ^ v[c],12);                           \
    v[a] += (m[sigma[i][e+1]] ^ cst[sigma[i][e]])+v[b];   \
    v[d] = ROT(v[d] ^ v[a], 8);                           \
    v[c] += v[d];                                         \
    v[b] = ROT(v[b] ^ v[c], 7);

	for (i = 0; i < 16; ++i)
		m[i] = U8TO32(block + i * 4);
	for (i = 0; i < 8; ++i)
		v[i] = S->h[i];
	v[8] = S->s[0] ^ 0x243F6A88;
	v[9] = S->s[1] ^ 0x85A308D3;
	v[10] = S->s[2] ^ 0x13198A2E;
	v[11] = S->s[3] ^ 0x03707344;
	v[12] = 0xA4093822;
	v[13] = 0x299F31D0;
	v[14] = 0x082EFA98;
	v[15] = 0xEC4E6C89;

	if (S->nullt == 0) {
		v[12] ^= S->t[0];
		v[13] ^= S->t[0];
		v[14] ^= S->t[1];
		v[15] ^= S->t[1];
	}

	for (i = 0; i < 14; ++i) {
		G(0, 4, 8, 12, 0);
		G(1, 5, 9, 13, 2);
		G(2, 6, 10, 14, 4);
		G(3, 7, 11, 15, 6);
		G(3, 4, 9, 14, 14);
		G(2, 7, 8, 13, 12);
		G(0, 5, 10, 15, 8);
		G(1, 6, 11, 12, 10);
	}

	for (i = 0; i < 16; ++i)
		S->h[i % 8] ^= v[i];
	for (i = 0; i < 8; ++i)
		S->h[i] ^= S->s[i % 4];
}

void blake256_init(state * S)
{
	S->h[0] = 0x6A09E667;
	S->h[1] = 0xBB67AE85;
	S->h[2] = 0x3C6EF372;
	S->h[3] = 0xA54FF53A;
	S->h[4] = 0x510E527F;
	S->h[5] = 0x9B05688C;
	S->h[6] = 0x1F83D9AB;
	S->h[7] = 0x5BE0CD19;
	S->t[0] = S->t[1] = S->buflen = S->nullt = 0;
	S->s[0] = S->s[1] = S->s[2] = S->s[3] = 0;
}

#if 0
void blake224_init(state * S)
{
	S->h[0] = 0xC1059ED8;
	S->h[1] = 0x367CD507;
	S->h[2] = 0x3070DD17;
	S->h[3] = 0xF70E5939;
	S->h[4] = 0xFFC00B31;
	S->h[5] = 0x68581511;
	S->h[6] = 0x64F98FA7;
	S->h[7] = 0xBEFA4FA4;
	S->t[0] = S->t[1] = S->buflen = S->nullt = 0;
	S->s[0] = S->s[1] = S->s[2] = S->s[3] = 0;
}
#endif

// datalen = number of bits
void blake256_update(state * S, const uint8_t * data, uint64_t datalen)
{
	int left = S->buflen >> 3;
	int fill = 64 - left;

	if (left && (((datalen >> 3)) >= (unsigned) fill)) {
		memcpy((void *) (S->buf + left), (void *) data, fill);
		S->t[0] += 512;
		if (S->t[0] == 0)
			S->t[1]++;
		blake256_compress(S, S->buf);
		data += fill;
		datalen -= (fill << 3);
		left = 0;
	}

	while (datalen >= 512) {
		S->t[0] += 512;
		if (S->t[0] == 0)
			S->t[1]++;
		blake256_compress(S, data);
		data += 64;
		datalen -= 512;
	}

	if (datalen > 0) {
		memcpy((void *) (S->buf + left), (void *) data, datalen >> 3);
		S->buflen = (left << 3) + datalen;
	} else {
		S->buflen = 0;
	}
}

#if 0
// datalen = number of bits
void blake224_update(state * S, const uint8_t * data, uint64_t datalen)
{
	blake256_update(S, data, datalen);
}
#endif

void blake256_final_h(state * S, uint8_t * digest, uint8_t pa, uint8_t pb)
{
	uint8_t msglen[8];
	uint32_t lo = S->t[0] + S->buflen, hi = S->t[1];
	if (lo < (unsigned) S->buflen)
		hi++;
	U32TO8(msglen + 0, hi);
	U32TO8(msglen + 4, lo);

	if (S->buflen == 440) {	/* one padding byte */
		S->t[0] -= 8;
		blake256_update(S, &pa, 8);
	} else {
		if (S->buflen < 440) {	/* enough space to fill the block  */
			if (S->buflen == 0)
				S->nullt = 1;
			S->t[0] -= 440 - S->buflen;
			blake256_update(S, padding, 440 - S->buflen);
		} else {	/* need 2 compressions */
			S->t[0] -= 512 - S->buflen;
			blake256_update(S, padding, 512 - S->buflen);
			S->t[0] -= 440;
			blake256_update(S, padding + 1, 440);
			S->nullt = 1;
		}
		blake256_update(S, &pb, 8);
		S->t[0] -= 8;
	}
	S->t[0] -= 64;
	blake256_update(S, msglen, 64);

	U32TO8(digest + 0, S->h[0]);
	U32TO8(digest + 4, S->h[1]);
	U32TO8(digest + 8, S->h[2]);
	U32TO8(digest + 12, S->h[3]);
	U32TO8(digest + 16, S->h[4]);
	U32TO8(digest + 20, S->h[5]);
	U32TO8(digest + 24, S->h[6]);
	U32TO8(digest + 28, S->h[7]);
}

void blake256_final(state * S, uint8_t * digest)
{
	blake256_final_h(S, digest, 0x81, 0x01);
}

#if 0
void blake224_final(state * S, uint8_t * digest)
{
	blake256_final_h(S, digest, 0x80, 0x00);
}
#endif

// inlen = number of bytes
void blake256_hash(uint8_t * out, const uint8_t * in, uint64_t inlen)
{
	state S;
	blake256_init(&S);
	blake256_update(&S, in, inlen * 8);
	blake256_final(&S, out);
}

#if 0
// inlen = number of bytes
void blake224_hash(uint8_t * out, const uint8_t * in, uint64_t inlen)
{
	state S;
	blake224_init(&S);
	blake224_update(&S, in, inlen * 8);
	blake224_final(&S, out);
}

// keylen = number of bytes
void hmac_blake256_init(hmac_state * S, const uint8_t * _key, uint64_t keylen)
{
	const uint8_t *key = _key;
	uint8_t keyhash[32];
	uint8_t pad[64];
	uint64_t i;

	if (keylen > 64) {
		blake256_hash(keyhash, key, keylen);
		key = keyhash;
		keylen = 32;
	}

	blake256_init(&S->inner);
	memset(pad, 0x36, 64);
	for (i = 0; i < keylen; ++i) {
		pad[i] ^= key[i];
	}
	blake256_update(&S->inner, pad, 512);

	blake256_init(&S->outer);
	memset(pad, 0x5c, 64);
	for (i = 0; i < keylen; ++i) {
		pad[i] ^= key[i];
	}
	blake256_update(&S->outer, pad, 512);

#if 0
	memset(keyhash, 0, 32);
#endif
}

// keylen = number of bytes
void hmac_blake224_init(hmac_state * S, const uint8_t * _key, uint64_t keylen)
{
	const uint8_t *key = _key;
	uint8_t keyhash[32];
	uint8_t pad[64];
	uint64_t i;

	if (keylen > 64) {
		blake256_hash(keyhash, key, keylen);
		key = keyhash;
		keylen = 28;
	}

	blake224_init(&S->inner);
	memset(pad, 0x36, 64);
	for (i = 0; i < keylen; ++i) {
		pad[i] ^= key[i];
	}
	blake224_update(&S->inner, pad, 512);

	blake224_init(&S->outer);
	memset(pad, 0x5c, 64);
	for (i = 0; i < keylen; ++i) {
		pad[i] ^= key[i];
	}
	blake224_update(&S->outer, pad, 512);

#if 0
	memset(keyhash, 0, 32);
#endif
}

// datalen = number of bits
void hmac_blake256_update(hmac_state * S, const uint8_t * data,
    uint64_t datalen)
{
	// update the inner state
	blake256_update(&S->inner, data, datalen);
}

// datalen = number of bits
void hmac_blake224_update(hmac_state * S, const uint8_t * data,
    uint64_t datalen)
{
	// update the inner state
	blake224_update(&S->inner, data, datalen);
}

void hmac_blake256_final(hmac_state * S, uint8_t * digest)
{
	uint8_t ihash[32];
	blake256_final(&S->inner, ihash);
	blake256_update(&S->outer, ihash, 256);
	blake256_final(&S->outer, digest);
#if 0
	memset(ihash, 0, 32);
#endif
}

void hmac_blake224_final(hmac_state * S, uint8_t * digest)
{
	uint8_t ihash[32];
	blake224_final(&S->inner, ihash);
	blake224_update(&S->outer, ihash, 224);
	blake224_final(&S->outer, digest);
#if 0
	memset(ihash, 0, 32);
#endif
}

// keylen = number of bytes; inlen = number of bytes
void hmac_blake256_hash(uint8_t * out, const uint8_t * key, uint64_t keylen,
    const uint8_t * in, uint64_t inlen)
{
	hmac_state S;
	hmac_blake256_init(&S, key, keylen);
	hmac_blake256_update(&S, in, inlen * 8);
	hmac_blake256_final(&S, out);
}

// keylen = number of bytes; inlen = number of bytes
void hmac_blake224_hash(uint8_t * out, const uint8_t * key, uint64_t keylen,
    const uint8_t * in, uint64_t inlen)
{
	hmac_state S;
	hmac_blake224_init(&S, key, keylen);
	hmac_blake224_update(&S, in, inlen * 8);
	hmac_blake224_final(&S, out);
}
#endif
