src/common/sha1.c - cloudberry - Git at Google

 /*-------------------------------------------------------------------------
  *
  *	sha1.c
  *	  Implements the SHA1 Secure Hash Algorithm
  *
  * Fallback implementation of SHA1, as specified in RFC 3174.
  *
  * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
  *	  src/common/sha1.c
  *
  *-------------------------------------------------------------------------
  */

 /*	   $KAME: sha1.c,v 1.3 2000/02/22 14:01:18 itojun Exp $    */

 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
  * All rights reserved.
  *
  * 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://www.itl.nist.gov/fipspubs/fip180-1.htm
  * implemented by Jun-ichiro itojun Itoh <itojun@itojun.org>
  */

 #ifndef FRONTEND
 #include "postgres.h"
 #else
 #include "postgres_fe.h"
 #endif

 #include <sys/param.h>

 #include "sha1_int.h"

 /* constant table */
 static uint32 _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)	(ctx->h.b32[(n)])
 #define COUNT	(ctx->count)
 #define BCOUNT	(ctx->c.b64[0] / 8)
 #define W(n)	(ctx->m.b32[(n)])

 #define PUTPAD(x) \
 do { \
 	ctx->m.b8[(COUNT % 64)] = (x);		\
 	COUNT++;				\
 	COUNT %= 64;				\
 	if (COUNT % 64 == 0)			\
 		sha1_step(ctx);		\
 } while (0)

 static void
 sha1_step(pg_sha1_ctx *ctx)
 {
 	uint32		a,
 				b,
 				c,
 				d,
 				e;
 	size_t		t,
 				s;
 	uint32		tmp;

 #ifndef WORDS_BIGENDIAN
 	pg_sha1_ctx tctx;

 	memmove(&tctx.m.b8[0], &ctx->m.b8[0], 64);
 	ctx->m.b8[0] = tctx.m.b8[3];
 	ctx->m.b8[1] = tctx.m.b8[2];
 	ctx->m.b8[2] = tctx.m.b8[1];
 	ctx->m.b8[3] = tctx.m.b8[0];
 	ctx->m.b8[4] = tctx.m.b8[7];
 	ctx->m.b8[5] = tctx.m.b8[6];
 	ctx->m.b8[6] = tctx.m.b8[5];
 	ctx->m.b8[7] = tctx.m.b8[4];
 	ctx->m.b8[8] = tctx.m.b8[11];
 	ctx->m.b8[9] = tctx.m.b8[10];
 	ctx->m.b8[10] = tctx.m.b8[9];
 	ctx->m.b8[11] = tctx.m.b8[8];
 	ctx->m.b8[12] = tctx.m.b8[15];
 	ctx->m.b8[13] = tctx.m.b8[14];
 	ctx->m.b8[14] = tctx.m.b8[13];
 	ctx->m.b8[15] = tctx.m.b8[12];
 	ctx->m.b8[16] = tctx.m.b8[19];
 	ctx->m.b8[17] = tctx.m.b8[18];
 	ctx->m.b8[18] = tctx.m.b8[17];
 	ctx->m.b8[19] = tctx.m.b8[16];
 	ctx->m.b8[20] = tctx.m.b8[23];
 	ctx->m.b8[21] = tctx.m.b8[22];
 	ctx->m.b8[22] = tctx.m.b8[21];
 	ctx->m.b8[23] = tctx.m.b8[20];
 	ctx->m.b8[24] = tctx.m.b8[27];
 	ctx->m.b8[25] = tctx.m.b8[26];
 	ctx->m.b8[26] = tctx.m.b8[25];
 	ctx->m.b8[27] = tctx.m.b8[24];
 	ctx->m.b8[28] = tctx.m.b8[31];
 	ctx->m.b8[29] = tctx.m.b8[30];
 	ctx->m.b8[30] = tctx.m.b8[29];
 	ctx->m.b8[31] = tctx.m.b8[28];
 	ctx->m.b8[32] = tctx.m.b8[35];
 	ctx->m.b8[33] = tctx.m.b8[34];
 	ctx->m.b8[34] = tctx.m.b8[33];
 	ctx->m.b8[35] = tctx.m.b8[32];
 	ctx->m.b8[36] = tctx.m.b8[39];
 	ctx->m.b8[37] = tctx.m.b8[38];
 	ctx->m.b8[38] = tctx.m.b8[37];
 	ctx->m.b8[39] = tctx.m.b8[36];
 	ctx->m.b8[40] = tctx.m.b8[43];
 	ctx->m.b8[41] = tctx.m.b8[42];
 	ctx->m.b8[42] = tctx.m.b8[41];
 	ctx->m.b8[43] = tctx.m.b8[40];
 	ctx->m.b8[44] = tctx.m.b8[47];
 	ctx->m.b8[45] = tctx.m.b8[46];
 	ctx->m.b8[46] = tctx.m.b8[45];
 	ctx->m.b8[47] = tctx.m.b8[44];
 	ctx->m.b8[48] = tctx.m.b8[51];
 	ctx->m.b8[49] = tctx.m.b8[50];
 	ctx->m.b8[50] = tctx.m.b8[49];
 	ctx->m.b8[51] = tctx.m.b8[48];
 	ctx->m.b8[52] = tctx.m.b8[55];
 	ctx->m.b8[53] = tctx.m.b8[54];
 	ctx->m.b8[54] = tctx.m.b8[53];
 	ctx->m.b8[55] = tctx.m.b8[52];
 	ctx->m.b8[56] = tctx.m.b8[59];
 	ctx->m.b8[57] = tctx.m.b8[58];
 	ctx->m.b8[58] = tctx.m.b8[57];
 	ctx->m.b8[59] = tctx.m.b8[56];
 	ctx->m.b8[60] = tctx.m.b8[63];
 	ctx->m.b8[61] = tctx.m.b8[62];
 	ctx->m.b8[62] = tctx.m.b8[61];
 	ctx->m.b8[63] = tctx.m.b8[60];
 #endif

 	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;

 	memset(&ctx->m.b8[0], 0, 64);
 }

 static void
 sha1_pad(pg_sha1_ctx *ctx)
 {
 	size_t		padlen;			/* pad length in bytes */
 	size_t		padstart;

 	PUTPAD(0x80);

 	padstart = COUNT % 64;
 	padlen = 64 - padstart;
 	if (padlen < 8)
 	{
 		memset(&ctx->m.b8[padstart], 0, padlen);
 		COUNT += padlen;
 		COUNT %= 64;
 		sha1_step(ctx);
 		padstart = COUNT % 64;	/* should be 0 */
 		padlen = 64 - padstart; /* should be 64 */
 	}
 	memset(&ctx->m.b8[padstart], 0, padlen - 8);
 	COUNT += (padlen - 8);
 	COUNT %= 64;
 #ifdef WORDS_BIGENDIAN
 	PUTPAD(ctx->c.b8[0]);
 	PUTPAD(ctx->c.b8[1]);
 	PUTPAD(ctx->c.b8[2]);
 	PUTPAD(ctx->c.b8[3]);
 	PUTPAD(ctx->c.b8[4]);
 	PUTPAD(ctx->c.b8[5]);
 	PUTPAD(ctx->c.b8[6]);
 	PUTPAD(ctx->c.b8[7]);
 #else
 	PUTPAD(ctx->c.b8[7]);
 	PUTPAD(ctx->c.b8[6]);
 	PUTPAD(ctx->c.b8[5]);
 	PUTPAD(ctx->c.b8[4]);
 	PUTPAD(ctx->c.b8[3]);
 	PUTPAD(ctx->c.b8[2]);
 	PUTPAD(ctx->c.b8[1]);
 	PUTPAD(ctx->c.b8[0]);
 #endif
 }

 static void
 sha1_result(uint8 *digest0, pg_sha1_ctx *ctx)
 {
 	uint8	   *digest;

 	digest = (uint8 *) digest0;

 #ifdef WORDS_BIGENDIAN
 	memmove(digest, &ctx->h.b8[0], 20);
 #else
 	digest[0] = ctx->h.b8[3];
 	digest[1] = ctx->h.b8[2];
 	digest[2] = ctx->h.b8[1];
 	digest[3] = ctx->h.b8[0];
 	digest[4] = ctx->h.b8[7];
 	digest[5] = ctx->h.b8[6];
 	digest[6] = ctx->h.b8[5];
 	digest[7] = ctx->h.b8[4];
 	digest[8] = ctx->h.b8[11];
 	digest[9] = ctx->h.b8[10];
 	digest[10] = ctx->h.b8[9];
 	digest[11] = ctx->h.b8[8];
 	digest[12] = ctx->h.b8[15];
 	digest[13] = ctx->h.b8[14];
 	digest[14] = ctx->h.b8[13];
 	digest[15] = ctx->h.b8[12];
 	digest[16] = ctx->h.b8[19];
 	digest[17] = ctx->h.b8[18];
 	digest[18] = ctx->h.b8[17];
 	digest[19] = ctx->h.b8[16];
 #endif
 }

 /* External routines for this SHA1 implementation */

 /*
  * pg_sha1_init
  *
  * Initialize a SHA1 context.
  */
 void
 pg_sha1_init(pg_sha1_ctx *ctx)
 {
 	memset(ctx, 0, sizeof(pg_sha1_ctx));
 	H(0) = 0x67452301;
 	H(1) = 0xefcdab89;
 	H(2) = 0x98badcfe;
 	H(3) = 0x10325476;
 	H(4) = 0xc3d2e1f0;
 }

 /*
  * pg_sha1_update
  *
  * Update a SHA1 context.
  */
 void
 pg_sha1_update(pg_sha1_ctx *ctx, const uint8 *data, size_t len)
 {
 	const uint8 *input;
 	size_t		gaplen;
 	size_t		gapstart;
 	size_t		off;
 	size_t		copysiz;

 	input = (const uint8 *) data;
 	off = 0;

 	while (off < len)
 	{
 		gapstart = COUNT % 64;
 		gaplen = 64 - gapstart;

 		copysiz = (gaplen < len - off) ? gaplen : len - off;
 		memmove(&ctx->m.b8[gapstart], &input[off], copysiz);
 		COUNT += copysiz;
 		COUNT %= 64;
 		ctx->c.b64[0] += copysiz * 8;
 		if (COUNT % 64 == 0)
 			sha1_step(ctx);
 		off += copysiz;
 	}
 }

 /*
  * pg_sha1_final
  *
  * Finalize a SHA1 context.
  */
 void
 pg_sha1_final(pg_sha1_ctx *ctx, uint8 *dest)
 {
 	sha1_pad(ctx);
 	sha1_result(dest, ctx);
 }
	/*-------------------------------------------------------------------------
	*
	* sha1.c
	* Implements the SHA1 Secure Hash Algorithm
	*
	* Fallback implementation of SHA1, as specified in RFC 3174.
	*
	* Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
	* Portions Copyright (c) 1994, Regents of the University of California
	*
	* IDENTIFICATION
	* src/common/sha1.c
	*
	*-------------------------------------------------------------------------
	*/

	/* $KAME: sha1.c,v 1.3 2000/02/22 14:01:18 itojun Exp $ */

	/*
	* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
	* All rights reserved.
	*
	* 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://www.itl.nist.gov/fipspubs/fip180-1.htm
	* implemented by Jun-ichiro itojun Itoh <itojun@itojun.org>
	*/

	#ifndef FRONTEND
	#include "postgres.h"
	#else
	#include "postgres_fe.h"
	#endif

	#include <sys/param.h>

	#include "sha1_int.h"

	/* constant table */
	static uint32 _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) (ctx->h.b32[(n)])
	#define COUNT (ctx->count)
	#define BCOUNT (ctx->c.b64[0] / 8)
	#define W(n) (ctx->m.b32[(n)])

	#define PUTPAD(x) \
	do { \
	ctx->m.b8[(COUNT % 64)] = (x); \
	COUNT++; \
	COUNT %= 64; \
	if (COUNT % 64 == 0) \
	sha1_step(ctx); \
	} while (0)

	static void
	sha1_step(pg_sha1_ctx *ctx)
	{
	uint32 a,
	b,
	c,
	d,
	e;
	size_t t,
	s;
	uint32 tmp;

	#ifndef WORDS_BIGENDIAN
	pg_sha1_ctx tctx;

	memmove(&tctx.m.b8[0], &ctx->m.b8[0], 64);
	ctx->m.b8[0] = tctx.m.b8[3];
	ctx->m.b8[1] = tctx.m.b8[2];
	ctx->m.b8[2] = tctx.m.b8[1];
	ctx->m.b8[3] = tctx.m.b8[0];
	ctx->m.b8[4] = tctx.m.b8[7];
	ctx->m.b8[5] = tctx.m.b8[6];
	ctx->m.b8[6] = tctx.m.b8[5];
	ctx->m.b8[7] = tctx.m.b8[4];
	ctx->m.b8[8] = tctx.m.b8[11];
	ctx->m.b8[9] = tctx.m.b8[10];
	ctx->m.b8[10] = tctx.m.b8[9];
	ctx->m.b8[11] = tctx.m.b8[8];
	ctx->m.b8[12] = tctx.m.b8[15];
	ctx->m.b8[13] = tctx.m.b8[14];
	ctx->m.b8[14] = tctx.m.b8[13];
	ctx->m.b8[15] = tctx.m.b8[12];
	ctx->m.b8[16] = tctx.m.b8[19];
	ctx->m.b8[17] = tctx.m.b8[18];
	ctx->m.b8[18] = tctx.m.b8[17];
	ctx->m.b8[19] = tctx.m.b8[16];
	ctx->m.b8[20] = tctx.m.b8[23];
	ctx->m.b8[21] = tctx.m.b8[22];
	ctx->m.b8[22] = tctx.m.b8[21];
	ctx->m.b8[23] = tctx.m.b8[20];
	ctx->m.b8[24] = tctx.m.b8[27];
	ctx->m.b8[25] = tctx.m.b8[26];
	ctx->m.b8[26] = tctx.m.b8[25];
	ctx->m.b8[27] = tctx.m.b8[24];
	ctx->m.b8[28] = tctx.m.b8[31];
	ctx->m.b8[29] = tctx.m.b8[30];
	ctx->m.b8[30] = tctx.m.b8[29];
	ctx->m.b8[31] = tctx.m.b8[28];
	ctx->m.b8[32] = tctx.m.b8[35];
	ctx->m.b8[33] = tctx.m.b8[34];
	ctx->m.b8[34] = tctx.m.b8[33];
	ctx->m.b8[35] = tctx.m.b8[32];
	ctx->m.b8[36] = tctx.m.b8[39];
	ctx->m.b8[37] = tctx.m.b8[38];
	ctx->m.b8[38] = tctx.m.b8[37];
	ctx->m.b8[39] = tctx.m.b8[36];
	ctx->m.b8[40] = tctx.m.b8[43];
	ctx->m.b8[41] = tctx.m.b8[42];
	ctx->m.b8[42] = tctx.m.b8[41];
	ctx->m.b8[43] = tctx.m.b8[40];
	ctx->m.b8[44] = tctx.m.b8[47];
	ctx->m.b8[45] = tctx.m.b8[46];
	ctx->m.b8[46] = tctx.m.b8[45];
	ctx->m.b8[47] = tctx.m.b8[44];
	ctx->m.b8[48] = tctx.m.b8[51];
	ctx->m.b8[49] = tctx.m.b8[50];
	ctx->m.b8[50] = tctx.m.b8[49];
	ctx->m.b8[51] = tctx.m.b8[48];
	ctx->m.b8[52] = tctx.m.b8[55];
	ctx->m.b8[53] = tctx.m.b8[54];
	ctx->m.b8[54] = tctx.m.b8[53];
	ctx->m.b8[55] = tctx.m.b8[52];
	ctx->m.b8[56] = tctx.m.b8[59];
	ctx->m.b8[57] = tctx.m.b8[58];
	ctx->m.b8[58] = tctx.m.b8[57];
	ctx->m.b8[59] = tctx.m.b8[56];
	ctx->m.b8[60] = tctx.m.b8[63];
	ctx->m.b8[61] = tctx.m.b8[62];
	ctx->m.b8[62] = tctx.m.b8[61];
	ctx->m.b8[63] = tctx.m.b8[60];
	#endif

	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;

	memset(&ctx->m.b8[0], 0, 64);
	}

	static void
	sha1_pad(pg_sha1_ctx *ctx)
	{
	size_t padlen; /* pad length in bytes */
	size_t padstart;

	PUTPAD(0x80);

	padstart = COUNT % 64;
	padlen = 64 - padstart;
	if (padlen < 8)
	{
	memset(&ctx->m.b8[padstart], 0, padlen);
	COUNT += padlen;
	COUNT %= 64;
	sha1_step(ctx);
	padstart = COUNT % 64; /* should be 0 */
	padlen = 64 - padstart; /* should be 64 */
	}
	memset(&ctx->m.b8[padstart], 0, padlen - 8);
	COUNT += (padlen - 8);
	COUNT %= 64;
	#ifdef WORDS_BIGENDIAN
	PUTPAD(ctx->c.b8[0]);
	PUTPAD(ctx->c.b8[1]);
	PUTPAD(ctx->c.b8[2]);
	PUTPAD(ctx->c.b8[3]);
	PUTPAD(ctx->c.b8[4]);
	PUTPAD(ctx->c.b8[5]);
	PUTPAD(ctx->c.b8[6]);
	PUTPAD(ctx->c.b8[7]);
	#else
	PUTPAD(ctx->c.b8[7]);
	PUTPAD(ctx->c.b8[6]);
	PUTPAD(ctx->c.b8[5]);
	PUTPAD(ctx->c.b8[4]);
	PUTPAD(ctx->c.b8[3]);
	PUTPAD(ctx->c.b8[2]);
	PUTPAD(ctx->c.b8[1]);
	PUTPAD(ctx->c.b8[0]);
	#endif
	}

	static void
	sha1_result(uint8 digest0, pg_sha1_ctx ctx)
	{
	uint8 *digest;

	digest = (uint8 *) digest0;

	#ifdef WORDS_BIGENDIAN
	memmove(digest, &ctx->h.b8[0], 20);
	#else
	digest[0] = ctx->h.b8[3];
	digest[1] = ctx->h.b8[2];
	digest[2] = ctx->h.b8[1];
	digest[3] = ctx->h.b8[0];
	digest[4] = ctx->h.b8[7];
	digest[5] = ctx->h.b8[6];
	digest[6] = ctx->h.b8[5];
	digest[7] = ctx->h.b8[4];
	digest[8] = ctx->h.b8[11];
	digest[9] = ctx->h.b8[10];
	digest[10] = ctx->h.b8[9];
	digest[11] = ctx->h.b8[8];
	digest[12] = ctx->h.b8[15];
	digest[13] = ctx->h.b8[14];
	digest[14] = ctx->h.b8[13];
	digest[15] = ctx->h.b8[12];
	digest[16] = ctx->h.b8[19];
	digest[17] = ctx->h.b8[18];
	digest[18] = ctx->h.b8[17];
	digest[19] = ctx->h.b8[16];
	#endif
	}

	/* External routines for this SHA1 implementation */

	/*
	* pg_sha1_init
	*
	* Initialize a SHA1 context.
	*/
	void
	pg_sha1_init(pg_sha1_ctx *ctx)
	{
	memset(ctx, 0, sizeof(pg_sha1_ctx));
	H(0) = 0x67452301;
	H(1) = 0xefcdab89;
	H(2) = 0x98badcfe;
	H(3) = 0x10325476;
	H(4) = 0xc3d2e1f0;
	}

	/*
	* pg_sha1_update
	*
	* Update a SHA1 context.
	*/
	void
	pg_sha1_update(pg_sha1_ctx ctx, const uint8 data, size_t len)
	{
	const uint8 *input;
	size_t gaplen;
	size_t gapstart;
	size_t off;
	size_t copysiz;

	input = (const uint8 *) data;
	off = 0;

	while (off < len)
	{
	gapstart = COUNT % 64;
	gaplen = 64 - gapstart;

	copysiz = (gaplen < len - off) ? gaplen : len - off;
	memmove(&ctx->m.b8[gapstart], &input[off], copysiz);
	COUNT += copysiz;
	COUNT %= 64;
	ctx->c.b64[0] += copysiz * 8;
	if (COUNT % 64 == 0)
	sha1_step(ctx);
	off += copysiz;
	}
	}

	/*
	* pg_sha1_final
	*
	* Finalize a SHA1 context.
	*/
	void
	pg_sha1_final(pg_sha1_ctx ctx, uint8 dest)
	{
	sha1_pad(ctx);
	sha1_result(dest, ctx);
	}