/*
 *  Heiko Schocher, DENX Software Engineering, hs@denx.de.
 *  based on:
 *  FIPS-180-1 compliant SHA-1 implementation
 *
 *  Copyright (C) 2003-2006  Christophe Devine
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License, version 2.1 as published by the Free Software Foundation.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 */
/*
 *  The SHA-1 standard was published by NIST in 1993.
 *
 *  http://www.itl.nist.gov/fipspubs/fip180-1.htm
 */

#include <common.h>
#include <digest.h>
#include <init.h>
#include <linux/string.h>
#include <asm/byteorder.h>

#define SHA1_SUM_POS	-0x20
#define SHA1_SUM_LEN	20

typedef struct
{
	uint32_t total[2];	/*!< number of bytes processed	*/
	uint32_t state[5];	/*!< intermediate digest state	*/
	uint8_t buffer[64];	/*!< data block being processed */
}
sha1_context;

/*
 * 32-bit integer manipulation macros (big endian)
 */
#define GET_UINT32_BE(n,b,i) (n) = be32_to_cpu(((uint32_t*)(b))[i / 4])
#define PUT_UINT32_BE(n,b,i) ((uint32_t*)(b))[i / 4] = cpu_to_be32(n)

/*
 * SHA-1 context setup
 */
static void sha1_starts (sha1_context * ctx)
{
	ctx->total[0] = 0;
	ctx->total[1] = 0;

	ctx->state[0] = 0x67452301;
	ctx->state[1] = 0xEFCDAB89;
	ctx->state[2] = 0x98BADCFE;
	ctx->state[3] = 0x10325476;
	ctx->state[4] = 0xC3D2E1F0;
}

static void sha1_process (sha1_context * ctx, uint8_t data[64])
{
	uint32_t temp, W[16], A, B, C, D, E;

	GET_UINT32_BE (W[0], data, 0);
	GET_UINT32_BE (W[1], data, 4);
	GET_UINT32_BE (W[2], data, 8);
	GET_UINT32_BE (W[3], data, 12);
	GET_UINT32_BE (W[4], data, 16);
	GET_UINT32_BE (W[5], data, 20);
	GET_UINT32_BE (W[6], data, 24);
	GET_UINT32_BE (W[7], data, 28);
	GET_UINT32_BE (W[8], data, 32);
	GET_UINT32_BE (W[9], data, 36);
	GET_UINT32_BE (W[10], data, 40);
	GET_UINT32_BE (W[11], data, 44);
	GET_UINT32_BE (W[12], data, 48);
	GET_UINT32_BE (W[13], data, 52);
	GET_UINT32_BE (W[14], data, 56);
	GET_UINT32_BE (W[15], data, 60);

#define S(x,n)	((x << n) | ((x & 0xFFFFFFFF) >> (32 - n)))

#define R(t) (						\
	temp = W[(t -  3) & 0x0F] ^ W[(t - 8) & 0x0F] ^	\
	       W[(t - 14) & 0x0F] ^ W[ t      & 0x0F],	\
	( W[t & 0x0F] = S(temp,1) )			\
)

#define P(a,b,c,d,e,x)	{				\
	e += S(a,5) + F(b,c,d) + K + x; b = S(b,30);	\
}

	A = ctx->state[0];
	B = ctx->state[1];
	C = ctx->state[2];
	D = ctx->state[3];
	E = ctx->state[4];

#define F(x,y,z) (z ^ (x & (y ^ z)))
#define K 0x5A827999

	P (A, B, C, D, E, W[0]);
	P (E, A, B, C, D, W[1]);
	P (D, E, A, B, C, W[2]);
	P (C, D, E, A, B, W[3]);
	P (B, C, D, E, A, W[4]);
	P (A, B, C, D, E, W[5]);
	P (E, A, B, C, D, W[6]);
	P (D, E, A, B, C, W[7]);
	P (C, D, E, A, B, W[8]);
	P (B, C, D, E, A, W[9]);
	P (A, B, C, D, E, W[10]);
	P (E, A, B, C, D, W[11]);
	P (D, E, A, B, C, W[12]);
	P (C, D, E, A, B, W[13]);
	P (B, C, D, E, A, W[14]);
	P (A, B, C, D, E, W[15]);
	P (E, A, B, C, D, R (16));
	P (D, E, A, B, C, R (17));
	P (C, D, E, A, B, R (18));
	P (B, C, D, E, A, R (19));

#undef K
#undef F

#define F(x,y,z) (x ^ y ^ z)
#define K 0x6ED9EBA1

	P (A, B, C, D, E, R (20));
	P (E, A, B, C, D, R (21));
	P (D, E, A, B, C, R (22));
	P (C, D, E, A, B, R (23));
	P (B, C, D, E, A, R (24));
	P (A, B, C, D, E, R (25));
	P (E, A, B, C, D, R (26));
	P (D, E, A, B, C, R (27));
	P (C, D, E, A, B, R (28));
	P (B, C, D, E, A, R (29));
	P (A, B, C, D, E, R (30));
	P (E, A, B, C, D, R (31));
	P (D, E, A, B, C, R (32));
	P (C, D, E, A, B, R (33));
	P (B, C, D, E, A, R (34));
	P (A, B, C, D, E, R (35));
	P (E, A, B, C, D, R (36));
	P (D, E, A, B, C, R (37));
	P (C, D, E, A, B, R (38));
	P (B, C, D, E, A, R (39));

#undef K
#undef F

#define F(x,y,z) ((x & y) | (z & (x | y)))
#define K 0x8F1BBCDC

	P (A, B, C, D, E, R (40));
	P (E, A, B, C, D, R (41));
	P (D, E, A, B, C, R (42));
	P (C, D, E, A, B, R (43));
	P (B, C, D, E, A, R (44));
	P (A, B, C, D, E, R (45));
	P (E, A, B, C, D, R (46));
	P (D, E, A, B, C, R (47));
	P (C, D, E, A, B, R (48));
	P (B, C, D, E, A, R (49));
	P (A, B, C, D, E, R (50));
	P (E, A, B, C, D, R (51));
	P (D, E, A, B, C, R (52));
	P (C, D, E, A, B, R (53));
	P (B, C, D, E, A, R (54));
	P (A, B, C, D, E, R (55));
	P (E, A, B, C, D, R (56));
	P (D, E, A, B, C, R (57));
	P (C, D, E, A, B, R (58));
	P (B, C, D, E, A, R (59));

#undef K
#undef F

#define F(x,y,z) (x ^ y ^ z)
#define K 0xCA62C1D6

	P (A, B, C, D, E, R (60));
	P (E, A, B, C, D, R (61));
	P (D, E, A, B, C, R (62));
	P (C, D, E, A, B, R (63));
	P (B, C, D, E, A, R (64));
	P (A, B, C, D, E, R (65));
	P (E, A, B, C, D, R (66));
	P (D, E, A, B, C, R (67));
	P (C, D, E, A, B, R (68));
	P (B, C, D, E, A, R (69));
	P (A, B, C, D, E, R (70));
	P (E, A, B, C, D, R (71));
	P (D, E, A, B, C, R (72));
	P (C, D, E, A, B, R (73));
	P (B, C, D, E, A, R (74));
	P (A, B, C, D, E, R (75));
	P (E, A, B, C, D, R (76));
	P (D, E, A, B, C, R (77));
	P (C, D, E, A, B, R (78));
	P (B, C, D, E, A, R (79));

#undef K
#undef F

	ctx->state[0] += A;
	ctx->state[1] += B;
	ctx->state[2] += C;
	ctx->state[3] += D;
	ctx->state[4] += E;
}

/*
 * SHA-1 process buffer
 */
static void sha1_update (sha1_context * ctx, uint8_t *input, uint32_t ilen)
{
	uint32_t fill, left;

	if (ilen <= 0)
		return;

	left = ctx->total[0] & 0x3F;
	fill = 64 - left;

	ctx->total[0] += ilen;
	ctx->total[0] &= 0xFFFFFFFF;

	if (ctx->total[0] < ilen)
		ctx->total[1]++;

	if (left && ilen >= fill) {
		memcpy ((void *) (ctx->buffer + left), (void *) input, fill);
		sha1_process (ctx, ctx->buffer);
		input += fill;
		ilen -= fill;
		left = 0;
	}

	while (ilen >= 64) {
		sha1_process (ctx, input);
		input += 64;
		ilen -= 64;
	}

	if (ilen > 0) {
		memcpy ((void *) (ctx->buffer + left), (void *) input, ilen);
	}
}

static uint8_t sha1_padding[64] = {
	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
};

/*
 * SHA-1 final digest
 */
static void sha1_finish (sha1_context * ctx, uint8_t output[20])
{
	uint32_t last, padn;
	uint32_t high, low;
	uint8_t msglen[8];

	high = (ctx->total[0] >> 29)
		| (ctx->total[1] << 3);
	low = (ctx->total[0] << 3);

	PUT_UINT32_BE (high, msglen, 0);
	PUT_UINT32_BE (low, msglen, 4);

	last = ctx->total[0] & 0x3F;
	padn = (last < 56) ? (56 - last) : (120 - last);

	sha1_update (ctx, sha1_padding, padn);
	sha1_update (ctx, msglen, 8);

	PUT_UINT32_BE (ctx->state[0], output, 0);
	PUT_UINT32_BE (ctx->state[1], output, 4);
	PUT_UINT32_BE (ctx->state[2], output, 8);
	PUT_UINT32_BE (ctx->state[3], output, 12);
	PUT_UINT32_BE (ctx->state[4], output, 16);
}

struct sha1 {
	sha1_context context;
	struct digest d;
};

static int digest_sha1_init(struct digest *d)
{
	struct sha1 *m = container_of(d, struct sha1, d);

	sha1_starts(&m->context);

	return 0;
}

static int digest_sha1_update(struct digest *d, const void *data,
			     unsigned long len)
{
	struct sha1 *m = container_of(d, struct sha1, d);

	sha1_update(&m->context, (uint8_t*)data, len);

	return 0;
}

static int digest_sha1_final(struct digest *d, unsigned char *md)
{
	struct sha1 *m = container_of(d, struct sha1, d);

	sha1_finish(&m->context, md);

	return 0;
}

static struct sha1 m = {
	.d = {
		.name = "sha1",
		.init = digest_sha1_init,
		.update = digest_sha1_update,
		.final = digest_sha1_final,
		.length = SHA1_SUM_LEN,
	}
};

static int sha1_digest_register(void)
{
	digest_register(&m.d);

	return 0;
}
device_initcall(sha1_digest_register);