/*

 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.

 * All rights reserved.

 *

 * Copyright (c) 2005 Andrey Korotaev <unC0Rr@gmail.com>

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. Neither the name of the project nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 */

/*

 * FIPS pub 180-1: Secure Hash Algorithm (SHA-1)

 * based on: http://csrc.nist.gov/fips/fip180-1.txt

 * implemented by Jun-ichiro itojun Itoh <itojun@itojun.org>

 */

#include "sha1.h"

/* constant table */

static quint32 _K[] = { 0x5a827999, 0x6ed9eba1, 0x8f1bbcdc, 0xca62c1d6 };

#define	K(t)	_K[(t) / 20]

#define	F0(b, c, d)	(((b) & (c)) | ((~(b)) & (d)))

#define	F1(b, c, d)	(((b) ^ (c)) ^ (d))

#define	F2(b, c, d)	(((b) & (c)) | ((b) & (d)) | ((c) & (d)))

#define	F3(b, c, d)	(((b) ^ (c)) ^ (d))

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

#define	H(n)	(ctxt->h.b32[(n)])

#define	COUNT	(ctxt->count)

#define	BCOUNT	(ctxt->c.b64[0] / 8)

#define	W(n)	(ctxt->m.b32[(n)])

#define	PUTBYTE(x)	{ \

	ctxt->m.b8[(COUNT % 64)] = (x);		\

	COUNT++;				\

	COUNT %= 64;				\

	ctxt->c.b64[0] += 8;			\

	if (COUNT % 64 == 0)			\

		sha1_step(ctxt);		\

     }

#define	PUTPAD(x)	{ \

	ctxt->m.b8[(COUNT % 64)] = (x);		\

	COUNT++;				\

	COUNT %= 64;				\

	if (COUNT % 64 == 0)			\

		sha1_step(ctxt);		\

     }

static void sha1_step(struct sha1_ctxt *);

static void

sha1_step(struct sha1_ctxt *ctxt)

{

	quint32	a, b, c, d, e;

	size_t t, s;

	quint32	tmp;

	a = H(0); b = H(1); c = H(2); d = H(3); e = H(4);

	for (t = 0; t < 20; t++) {

		s = t & 0x0f;

		if (t >= 16) {

			W(s) = S(1, W((s+13) & 0x0f) ^ W((s+8) & 0x0f) ^ W((s+2) & 0x0f) ^ W(s));

		}

		tmp = S(5, a) + F0(b, c, d) + e + W(s) + K(t);

		e = d; d = c; c = S(30, b); b = a; a = tmp;

	}

	for (t = 20; t < 40; t++) {

		s = t & 0x0f;

		W(s) = S(1, W((s+13) & 0x0f) ^ W((s+8) & 0x0f) ^ W((s+2) & 0x0f) ^ W(s));

		tmp = S(5, a) + F1(b, c, d) + e + W(s) + K(t);

		e = d; d = c; c = S(30, b); b = a; a = tmp;

	}

	for (t = 40; t < 60; t++) {

		s = t & 0x0f;

		W(s) = S(1, W((s+13) & 0x0f) ^ W((s+8) & 0x0f) ^ W((s+2) & 0x0f) ^ W(s));

		tmp = S(5, a) + F2(b, c, d) + e + W(s) + K(t);

		e = d; d = c; c = S(30, b); b = a; a = tmp;

	}

	for (t = 60; t < 80; t++) {

		s = t & 0x0f;

		W(s) = S(1, W((s+13) & 0x0f) ^ W((s+8) & 0x0f) ^ W((s+2) & 0x0f) ^ W(s));

		tmp = S(5, a) + F3(b, c, d) + e + W(s) + K(t);

		e = d; d = c; c = S(30, b); b = a; a = tmp;

	}

	H(0) = H(0) + a;

	H(1) = H(1) + b;

	H(2) = H(2) + c;

	H(3) = H(3) + d;

	H(4) = H(4) + e;

	qMemSet(&ctxt->m.b8[0], 0, 64);

}

/*------------------------------------------------------------*/

void sha1_init(struct sha1_ctxt *ctxt)

{

	qMemSet(ctxt, 0, sizeof(struct sha1_ctxt));

	H(0) = 0x67452301;

	H(1) = 0xefcdab89;

	H(2) = 0x98badcfe;

	H(3) = 0x10325476;

	H(4) = 0xc3d2e1f0;

}

void sha1_pad(struct sha1_ctxt *ctxt)

{

	size_t padlen;		/*pad length in bytes*/

	size_t padstart;

	PUTPAD(0x80);

	padstart = COUNT % 64;

	padlen = 64 - padstart;

	if (padlen < 8) {

		qMemSet(&ctxt->m.b8[padstart], 0, padlen);

		COUNT += padlen;

		COUNT %= 64;

		sha1_step(ctxt);

		padstart = COUNT % 64;	/* should be 0 */

		padlen = 64 - padstart;	/* should be 64 */

	}

	qMemSet(&ctxt->m.b8[padstart], 0, padlen - 8);

	COUNT += (padlen - 8);

	COUNT %= 64;

	PUTPAD(ctxt->c.b8[0]); PUTPAD(ctxt->c.b8[1]);

	PUTPAD(ctxt->c.b8[2]); PUTPAD(ctxt->c.b8[3]);

	PUTPAD(ctxt->c.b8[4]); PUTPAD(ctxt->c.b8[5]);

	PUTPAD(ctxt->c.b8[6]); PUTPAD(ctxt->c.b8[7]);

}

void sha1_loop(struct sha1_ctxt *ctxt, const quint8 *input, size_t len)

{

	size_t gaplen;

	size_t gapstart;

	size_t off;

	size_t copysiz;

	off = 0;

	while (off < len) {

		gapstart = COUNT % 64;

		gaplen = 64 - gapstart;

		copysiz = (gaplen < len - off) ? gaplen : len - off;

		qMemCopy(&ctxt->m.b8[gapstart], &input[off], copysiz);

		COUNT += copysiz;

		COUNT %= 64;

		ctxt->c.b64[0] += copysiz * 8;

		if (COUNT % 64 == 0)

			sha1_step(ctxt);

		off += copysiz;

	}

}

void sha1_result(struct sha1_ctxt *ctxt, caddr_t digest0)

{

	quint8 *digest;

	digest = (quint8 *)digest0;

	sha1_pad(ctxt);

	qMemCopy(digest, &ctxt->h.b8[0], 20);

}