/* SHA-512 code by Jean-Luc Cooke <jlcooke@certainkey.com>
 *
 * Copyright (c) Jean-Luc Cooke <jlcooke@certainkey.com>
 * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
 * Copyright (c) 2003 Kyle McMartin <kyle@debian.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, or (at your option) any
 * later version.
 *
 */
#include <crypto/internal/hash.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/crypto.h>
#include <linux/types.h>
#include <crypto/sha.h>
#include <linux/percpu.h>
#include <asm/byteorder.h>

static inline u64 Ch(u64 x, u64 y, u64 z)
{
        return z ^ (x & (y ^ z));
}

static inline u64 Maj(u64 x, u64 y, u64 z)
{
        return (x & y) | (z & (x | y));
}

static inline u64 RORu64(u64 x, u64 y)
{
        return (x >> y) | (x << (64 - y));
}

static const u64 sha512_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,
};

#define e0(x)       (RORu64(x,28) ^ RORu64(x,34) ^ RORu64(x,39))
#define e1(x)       (RORu64(x,14) ^ RORu64(x,18) ^ RORu64(x,41))
#define s0(x)       (RORu64(x, 1) ^ RORu64(x, 8) ^ (x >> 7))
#define s1(x)       (RORu64(x,19) ^ RORu64(x,61) ^ (x >> 6))

static inline void LOAD_OP(int I, u64 *W, const u8 *input)
{
	W[I] = __be64_to_cpu( ((__be64*)(input))[I] );
}

static inline void BLEND_OP(int I, u64 *W)
{
	W[I % 16] += s1(W[(I-2) % 16]) + W[(I-7) % 16] + s0(W[(I-15) % 16]);
}

static void
sha512_transform(u64 *state, const u8 *input)
{
	u64 a, b, c, d, e, f, g, h, t1, t2;

	int i;
	u64 W[16];

	/* load the input */
        for (i = 0; i < 16; i++)
                LOAD_OP(i, W, input);

	/* load the state into our registers */
	a=state[0];   b=state[1];   c=state[2];   d=state[3];
	e=state[4];   f=state[5];   g=state[6];   h=state[7];

#define SHA512_0_15(i, a, b, c, d, e, f, g, h)			\
	t1 = h + e1(e) + Ch(e, f, g) + sha512_K[i] + W[i];	\
	t2 = e0(a) + Maj(a, b, c);				\
	d += t1;						\
	h = t1 + t2

#define SHA512_16_79(i, a, b, c, d, e, f, g, h)			\
	BLEND_OP(i, W);						\
	t1 = h + e1(e) + Ch(e, f, g) + sha512_K[i] + W[(i)%16];	\
	t2 = e0(a) + Maj(a, b, c);				\
	d += t1;						\
	h = t1 + t2

	for (i = 0; i < 16; i += 8) {
		SHA512_0_15(i, a, b, c, d, e, f, g, h);
		SHA512_0_15(i + 1, h, a, b, c, d, e, f, g);
		SHA512_0_15(i + 2, g, h, a, b, c, d, e, f);
		SHA512_0_15(i + 3, f, g, h, a, b, c, d, e);
		SHA512_0_15(i + 4, e, f, g, h, a, b, c, d);
		SHA512_0_15(i + 5, d, e, f, g, h, a, b, c);
		SHA512_0_15(i + 6, c, d, e, f, g, h, a, b);
		SHA512_0_15(i + 7, b, c, d, e, f, g, h, a);
	}
	for (i = 16; i < 80; i += 8) {
		SHA512_16_79(i, a, b, c, d, e, f, g, h);
		SHA512_16_79(i + 1, h, a, b, c, d, e, f, g);
		SHA512_16_79(i + 2, g, h, a, b, c, d, e, f);
		SHA512_16_79(i + 3, f, g, h, a, b, c, d, e);
		SHA512_16_79(i + 4, e, f, g, h, a, b, c, d);
		SHA512_16_79(i + 5, d, e, f, g, h, a, b, c);
		SHA512_16_79(i + 6, c, d, e, f, g, h, a, b);
		SHA512_16_79(i + 7, b, c, d, e, f, g, h, a);
	}

	state[0] += a; state[1] += b; state[2] += c; state[3] += d;
	state[4] += e; state[5] += f; state[6] += g; state[7] += h;

	/* erase our data */
	a = b = c = d = e = f = g = h = t1 = t2 = 0;
}

static int
sha512_init(struct shash_desc *desc)
{
	struct sha512_state *sctx = shash_desc_ctx(desc);
	sctx->state[0] = SHA512_H0;
	sctx->state[1] = SHA512_H1;
	sctx->state[2] = SHA512_H2;
	sctx->state[3] = SHA512_H3;
	sctx->state[4] = SHA512_H4;
	sctx->state[5] = SHA512_H5;
	sctx->state[6] = SHA512_H6;
	sctx->state[7] = SHA512_H7;
	sctx->count[0] = sctx->count[1] = 0;

	return 0;
}

static int
sha384_init(struct shash_desc *desc)
{
	struct sha512_state *sctx = shash_desc_ctx(desc);
	sctx->state[0] = SHA384_H0;
	sctx->state[1] = SHA384_H1;
	sctx->state[2] = SHA384_H2;
	sctx->state[3] = SHA384_H3;
	sctx->state[4] = SHA384_H4;
	sctx->state[5] = SHA384_H5;
	sctx->state[6] = SHA384_H6;
	sctx->state[7] = SHA384_H7;
	sctx->count[0] = sctx->count[1] = 0;

	return 0;
}

static int
sha512_update(struct shash_desc *desc, const u8 *data, unsigned int len)
{
	struct sha512_state *sctx = shash_desc_ctx(desc);

	unsigned int i, index, part_len;

	/* Compute number of bytes mod 128 */
	index = sctx->count[0] & 0x7f;

	/* Update number of bytes */
	if (!(sctx->count[0] += len))
		sctx->count[1]++;

        part_len = 128 - index;

	/* Transform as many times as possible. */
	if (len >= part_len) {
		memcpy(&sctx->buf[index], data, part_len);
		sha512_transform(sctx->state, sctx->buf);

		for (i = part_len; i + 127 < len; i+=128)
			sha512_transform(sctx->state, &data[i]);

		index = 0;
	} else {
		i = 0;
	}

	/* Buffer remaining input */
	memcpy(&sctx->buf[index], &data[i], len - i);

	return 0;
}

static int
sha512_final(struct shash_desc *desc, u8 *hash)
{
	struct sha512_state *sctx = shash_desc_ctx(desc);
        static u8 padding[128] = { 0x80, };
	__be64 *dst = (__be64 *)hash;
	__be64 bits[2];
	unsigned int index, pad_len;
	int i;

	/* Save number of bits */
	bits[1] = cpu_to_be64(sctx->count[0] << 3);
	bits[0] = cpu_to_be64(sctx->count[1] << 3 | sctx->count[0] >> 61);

	/* Pad out to 112 mod 128. */
	index = sctx->count[0] & 0x7f;
	pad_len = (index < 112) ? (112 - index) : ((128+112) - index);
	sha512_update(desc, padding, pad_len);

	/* Append length (before padding) */
	sha512_update(desc, (const u8 *)bits, sizeof(bits));

	/* Store state in digest */
	for (i = 0; i < 8; i++)
		dst[i] = cpu_to_be64(sctx->state[i]);

	/* Zeroize sensitive information. */
	memset(sctx, 0, sizeof(struct sha512_state));

	return 0;
}

static int sha384_final(struct shash_desc *desc, u8 *hash)
{
	u8 D[64];

	sha512_final(desc, D);

	memcpy(hash, D, 48);
	memset(D, 0, 64);

	return 0;
}

static struct shash_alg sha512 = {
	.digestsize	=	SHA512_DIGEST_SIZE,
	.init		=	sha512_init,
	.update		=	sha512_update,
	.final		=	sha512_final,
	.descsize	=	sizeof(struct sha512_state),
	.base		=	{
		.cra_name	=	"sha512",
		.cra_flags	=	CRYPTO_ALG_TYPE_SHASH,
		.cra_blocksize	=	SHA512_BLOCK_SIZE,
		.cra_module	=	THIS_MODULE,
	}
};

static struct shash_alg sha384 = {
	.digestsize	=	SHA384_DIGEST_SIZE,
	.init		=	sha384_init,
	.update		=	sha512_update,
	.final		=	sha384_final,
	.descsize	=	sizeof(struct sha512_state),
	.base		=	{
		.cra_name	=	"sha384",
		.cra_flags	=	CRYPTO_ALG_TYPE_SHASH,
		.cra_blocksize	=	SHA384_BLOCK_SIZE,
		.cra_module	=	THIS_MODULE,
	}
};

static int __init sha512_generic_mod_init(void)
{
        int ret = 0;

        if ((ret = crypto_register_shash(&sha384)) < 0)
                goto out;
        if ((ret = crypto_register_shash(&sha512)) < 0)
                crypto_unregister_shash(&sha384);
out:
        return ret;
}

static void __exit sha512_generic_mod_fini(void)
{
        crypto_unregister_shash(&sha384);
        crypto_unregister_shash(&sha512);
}

module_init(sha512_generic_mod_init);
module_exit(sha512_generic_mod_fini);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("SHA-512 and SHA-384 Secure Hash Algorithms");

MODULE_ALIAS("sha384");
MODULE_ALIAS("sha512");