/*
 * Cryptographic API.
 *
 * SHA-3, as specified in
 * http://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.202.pdf
 *
 * SHA-3 code by Jeff Garzik <jeff@garzik.org>
 *               Ard Biesheuvel <ard.biesheuvel@linaro.org>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)•
 * any later version.
 *
 */
#include <crypto/internal/hash.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/types.h>
#include <crypto/sha3.h>
#include <asm/byteorder.h>
#include <asm/unaligned.h>

#define KECCAK_ROUNDS 24

static const u64 keccakf_rndc[24] = {
	0x0000000000000001ULL, 0x0000000000008082ULL, 0x800000000000808aULL,
	0x8000000080008000ULL, 0x000000000000808bULL, 0x0000000080000001ULL,
	0x8000000080008081ULL, 0x8000000000008009ULL, 0x000000000000008aULL,
	0x0000000000000088ULL, 0x0000000080008009ULL, 0x000000008000000aULL,
	0x000000008000808bULL, 0x800000000000008bULL, 0x8000000000008089ULL,
	0x8000000000008003ULL, 0x8000000000008002ULL, 0x8000000000000080ULL,
	0x000000000000800aULL, 0x800000008000000aULL, 0x8000000080008081ULL,
	0x8000000000008080ULL, 0x0000000080000001ULL, 0x8000000080008008ULL
};

/* update the state with given number of rounds */

static void __attribute__((__optimize__("O3"))) keccakf(u64 st[25])
{
	u64 t[5], tt, bc[5];
	int round;

	for (round = 0; round < KECCAK_ROUNDS; round++) {

		/* Theta */
		bc[0] = st[0] ^ st[5] ^ st[10] ^ st[15] ^ st[20];
		bc[1] = st[1] ^ st[6] ^ st[11] ^ st[16] ^ st[21];
		bc[2] = st[2] ^ st[7] ^ st[12] ^ st[17] ^ st[22];
		bc[3] = st[3] ^ st[8] ^ st[13] ^ st[18] ^ st[23];
		bc[4] = st[4] ^ st[9] ^ st[14] ^ st[19] ^ st[24];

		t[0] = bc[4] ^ rol64(bc[1], 1);
		t[1] = bc[0] ^ rol64(bc[2], 1);
		t[2] = bc[1] ^ rol64(bc[3], 1);
		t[3] = bc[2] ^ rol64(bc[4], 1);
		t[4] = bc[3] ^ rol64(bc[0], 1);

		st[0] ^= t[0];

		/* Rho Pi */
		tt = st[1];
		st[ 1] = rol64(st[ 6] ^ t[1], 44);
		st[ 6] = rol64(st[ 9] ^ t[4], 20);
		st[ 9] = rol64(st[22] ^ t[2], 61);
		st[22] = rol64(st[14] ^ t[4], 39);
		st[14] = rol64(st[20] ^ t[0], 18);
		st[20] = rol64(st[ 2] ^ t[2], 62);
		st[ 2] = rol64(st[12] ^ t[2], 43);
		st[12] = rol64(st[13] ^ t[3], 25);
		st[13] = rol64(st[19] ^ t[4],  8);
		st[19] = rol64(st[23] ^ t[3], 56);
		st[23] = rol64(st[15] ^ t[0], 41);
		st[15] = rol64(st[ 4] ^ t[4], 27);
		st[ 4] = rol64(st[24] ^ t[4], 14);
		st[24] = rol64(st[21] ^ t[1],  2);
		st[21] = rol64(st[ 8] ^ t[3], 55);
		st[ 8] = rol64(st[16] ^ t[1], 45);
		st[16] = rol64(st[ 5] ^ t[0], 36);
		st[ 5] = rol64(st[ 3] ^ t[3], 28);
		st[ 3] = rol64(st[18] ^ t[3], 21);
		st[18] = rol64(st[17] ^ t[2], 15);
		st[17] = rol64(st[11] ^ t[1], 10);
		st[11] = rol64(st[ 7] ^ t[2],  6);
		st[ 7] = rol64(st[10] ^ t[0],  3);
		st[10] = rol64(    tt ^ t[1],  1);

		/* Chi */
		bc[ 0] = ~st[ 1] & st[ 2];
		bc[ 1] = ~st[ 2] & st[ 3];
		bc[ 2] = ~st[ 3] & st[ 4];
		bc[ 3] = ~st[ 4] & st[ 0];
		bc[ 4] = ~st[ 0] & st[ 1];
		st[ 0] ^= bc[ 0];
		st[ 1] ^= bc[ 1];
		st[ 2] ^= bc[ 2];
		st[ 3] ^= bc[ 3];
		st[ 4] ^= bc[ 4];

		bc[ 0] = ~st[ 6] & st[ 7];
		bc[ 1] = ~st[ 7] & st[ 8];
		bc[ 2] = ~st[ 8] & st[ 9];
		bc[ 3] = ~st[ 9] & st[ 5];
		bc[ 4] = ~st[ 5] & st[ 6];
		st[ 5] ^= bc[ 0];
		st[ 6] ^= bc[ 1];
		st[ 7] ^= bc[ 2];
		st[ 8] ^= bc[ 3];
		st[ 9] ^= bc[ 4];

		bc[ 0] = ~st[11] & st[12];
		bc[ 1] = ~st[12] & st[13];
		bc[ 2] = ~st[13] & st[14];
		bc[ 3] = ~st[14] & st[10];
		bc[ 4] = ~st[10] & st[11];
		st[10] ^= bc[ 0];
		st[11] ^= bc[ 1];
		st[12] ^= bc[ 2];
		st[13] ^= bc[ 3];
		st[14] ^= bc[ 4];

		bc[ 0] = ~st[16] & st[17];
		bc[ 1] = ~st[17] & st[18];
		bc[ 2] = ~st[18] & st[19];
		bc[ 3] = ~st[19] & st[15];
		bc[ 4] = ~st[15] & st[16];
		st[15] ^= bc[ 0];
		st[16] ^= bc[ 1];
		st[17] ^= bc[ 2];
		st[18] ^= bc[ 3];
		st[19] ^= bc[ 4];

		bc[ 0] = ~st[21] & st[22];
		bc[ 1] = ~st[22] & st[23];
		bc[ 2] = ~st[23] & st[24];
		bc[ 3] = ~st[24] & st[20];
		bc[ 4] = ~st[20] & st[21];
		st[20] ^= bc[ 0];
		st[21] ^= bc[ 1];
		st[22] ^= bc[ 2];
		st[23] ^= bc[ 3];
		st[24] ^= bc[ 4];

		/* Iota */
		st[0] ^= keccakf_rndc[round];
	}
}

static void sha3_init(struct sha3_state *sctx, unsigned int digest_sz)
{
	memset(sctx, 0, sizeof(*sctx));
	sctx->md_len = digest_sz;
	sctx->rsiz = 200 - 2 * digest_sz;
	sctx->rsizw = sctx->rsiz / 8;
}

static int sha3_224_init(struct shash_desc *desc)
{
	struct sha3_state *sctx = shash_desc_ctx(desc);

	sha3_init(sctx, SHA3_224_DIGEST_SIZE);
	return 0;
}

static int sha3_256_init(struct shash_desc *desc)
{
	struct sha3_state *sctx = shash_desc_ctx(desc);

	sha3_init(sctx, SHA3_256_DIGEST_SIZE);
	return 0;
}

static int sha3_384_init(struct shash_desc *desc)
{
	struct sha3_state *sctx = shash_desc_ctx(desc);

	sha3_init(sctx, SHA3_384_DIGEST_SIZE);
	return 0;
}

static int sha3_512_init(struct shash_desc *desc)
{
	struct sha3_state *sctx = shash_desc_ctx(desc);

	sha3_init(sctx, SHA3_512_DIGEST_SIZE);
	return 0;
}

static int sha3_update(struct shash_desc *desc, const u8 *data,
		       unsigned int len)
{
	struct sha3_state *sctx = shash_desc_ctx(desc);
	unsigned int done;
	const u8 *src;

	done = 0;
	src = data;

	if ((sctx->partial + len) > (sctx->rsiz - 1)) {
		if (sctx->partial) {
			done = -sctx->partial;
			memcpy(sctx->buf + sctx->partial, data,
			       done + sctx->rsiz);
			src = sctx->buf;
		}

		do {
			unsigned int i;

			for (i = 0; i < sctx->rsizw; i++)
				sctx->st[i] ^= get_unaligned_le64(src + 8 * i);
			keccakf(sctx->st);

			done += sctx->rsiz;
			src = data + done;
		} while (done + (sctx->rsiz - 1) < len);

		sctx->partial = 0;
	}
	memcpy(sctx->buf + sctx->partial, src, len - done);
	sctx->partial += (len - done);

	return 0;
}

static int sha3_final(struct shash_desc *desc, u8 *out)
{
	struct sha3_state *sctx = shash_desc_ctx(desc);
	unsigned int i, inlen = sctx->partial;

	sctx->buf[inlen++] = 0x06;
	memset(sctx->buf + inlen, 0, sctx->rsiz - inlen);
	sctx->buf[sctx->rsiz - 1] |= 0x80;

	for (i = 0; i < sctx->rsizw; i++)
		sctx->st[i] ^= get_unaligned_le64(sctx->buf + 8 * i);

	keccakf(sctx->st);

	for (i = 0; i < sctx->rsizw; i++)
		sctx->st[i] = cpu_to_le64(sctx->st[i]);

	memcpy(out, sctx->st, sctx->md_len);

	memset(sctx, 0, sizeof(*sctx));
	return 0;
}

static struct shash_alg sha3_224 = {
	.digestsize	=	SHA3_224_DIGEST_SIZE,
	.init		=	sha3_224_init,
	.update		=	sha3_update,
	.final		=	sha3_final,
	.descsize	=	sizeof(struct sha3_state),
	.base		=	{
		.cra_name	=	"sha3-224",
		.cra_driver_name =	"sha3-224-generic",
		.cra_flags	=	CRYPTO_ALG_TYPE_SHASH,
		.cra_blocksize	=	SHA3_224_BLOCK_SIZE,
		.cra_module	=	THIS_MODULE,
	}
};

static struct shash_alg sha3_256 = {
	.digestsize	=	SHA3_256_DIGEST_SIZE,
	.init		=	sha3_256_init,
	.update		=	sha3_update,
	.final		=	sha3_final,
	.descsize	=	sizeof(struct sha3_state),
	.base		=	{
		.cra_name	=	"sha3-256",
		.cra_driver_name =	"sha3-256-generic",
		.cra_flags	=	CRYPTO_ALG_TYPE_SHASH,
		.cra_blocksize	=	SHA3_256_BLOCK_SIZE,
		.cra_module	=	THIS_MODULE,
	}
};

static struct shash_alg sha3_384 = {
	.digestsize	=	SHA3_384_DIGEST_SIZE,
	.init		=	sha3_384_init,
	.update		=	sha3_update,
	.final		=	sha3_final,
	.descsize	=	sizeof(struct sha3_state),
	.base		=	{
		.cra_name	=	"sha3-384",
		.cra_driver_name =	"sha3-384-generic",
		.cra_flags	=	CRYPTO_ALG_TYPE_SHASH,
		.cra_blocksize	=	SHA3_384_BLOCK_SIZE,
		.cra_module	=	THIS_MODULE,
	}
};

static struct shash_alg sha3_512 = {
	.digestsize	=	SHA3_512_DIGEST_SIZE,
	.init		=	sha3_512_init,
	.update		=	sha3_update,
	.final		=	sha3_final,
	.descsize	=	sizeof(struct sha3_state),
	.base		=	{
		.cra_name	=	"sha3-512",
		.cra_driver_name =	"sha3-512-generic",
		.cra_flags	=	CRYPTO_ALG_TYPE_SHASH,
		.cra_blocksize	=	SHA3_512_BLOCK_SIZE,
		.cra_module	=	THIS_MODULE,
	}
};

static int __init sha3_generic_mod_init(void)
{
	int ret;

	ret = crypto_register_shash(&sha3_224);
	if (ret < 0)
		goto err_out;
	ret = crypto_register_shash(&sha3_256);
	if (ret < 0)
		goto err_out_224;
	ret = crypto_register_shash(&sha3_384);
	if (ret < 0)
		goto err_out_256;
	ret = crypto_register_shash(&sha3_512);
	if (ret < 0)
		goto err_out_384;

	return 0;

err_out_384:
	crypto_unregister_shash(&sha3_384);
err_out_256:
	crypto_unregister_shash(&sha3_256);
err_out_224:
	crypto_unregister_shash(&sha3_224);
err_out:
	return ret;
}

static void __exit sha3_generic_mod_fini(void)
{
	crypto_unregister_shash(&sha3_224);
	crypto_unregister_shash(&sha3_256);
	crypto_unregister_shash(&sha3_384);
	crypto_unregister_shash(&sha3_512);
}

module_init(sha3_generic_mod_init);
module_exit(sha3_generic_mod_fini);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("SHA-3 Secure Hash Algorithm");

MODULE_ALIAS_CRYPTO("sha3-224");
MODULE_ALIAS_CRYPTO("sha3-224-generic");
MODULE_ALIAS_CRYPTO("sha3-256");
MODULE_ALIAS_CRYPTO("sha3-256-generic");
MODULE_ALIAS_CRYPTO("sha3-384");
MODULE_ALIAS_CRYPTO("sha3-384-generic");
MODULE_ALIAS_CRYPTO("sha3-512");
MODULE_ALIAS_CRYPTO("sha3-512-generic");