lib/md5.c - quagga - Gitiles

 /* $USAGI: md5.c,v 1.2 2000/11/02 11:59:24 yoshfuji Exp $ */
 /*	$KAME: md5.c,v 1.2 2000/05/27 07:07:48 jinmei Exp $	*/
 /*	$Id: md5.c,v 1.6 2006/01/17 23:39:04 vincent Exp $ */

 /*
  * Copyright (C) 2004 6WIND
  *                          <Vincent.Jardin@6WIND.com>
  * All rights reserved.
  *
  * This MD5 code is Big endian and Little Endian compatible.
  */

 /*
  * 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.
  */

 #include <zebra.h>
 #include "md5.h"

 #define SHIFT(X, s) (((X) << (s)) | ((X) >> (32 - (s))))

 #define F(X, Y, Z) (((X) & (Y)) | ((~X) & (Z)))
 #define G(X, Y, Z) (((X) & (Z)) | ((Y) & (~Z)))
 #define H(X, Y, Z) ((X) ^ (Y) ^ (Z))
 #define I(X, Y, Z) ((Y) ^ ((X) | (~Z)))

 #define ROUND1(a, b, c, d, k, s, i) { \
 	(a) = (a) + F((b), (c), (d)) + X[(k)] + T[(i)]; \
 	(a) = SHIFT((a), (s)); \
 	(a) = (b) + (a); \
 }

 #define ROUND2(a, b, c, d, k, s, i) { \
 	(a) = (a) + G((b), (c), (d)) + X[(k)] + T[(i)]; \
 	(a) = SHIFT((a), (s)); \
 	(a) = (b) + (a); \
 }

 #define ROUND3(a, b, c, d, k, s, i) { \
 	(a) = (a) + H((b), (c), (d)) + X[(k)] + T[(i)]; \
 	(a) = SHIFT((a), (s)); \
 	(a) = (b) + (a); \
 }

 #define ROUND4(a, b, c, d, k, s, i) { \
 	(a) = (a) + I((b), (c), (d)) + X[(k)] + T[(i)]; \
 	(a) = SHIFT((a), (s)); \
 	(a) = (b) + (a); \
 }

 #define Sa	 7
 #define Sb	12
 #define Sc	17
 #define Sd	22

 #define Se	 5
 #define Sf	 9
 #define Sg	14
 #define Sh	20

 #define Si	 4
 #define Sj	11
 #define Sk	16
 #define Sl	23

 #define Sm	 6
 #define Sn	10
 #define So	15
 #define Sp	21

 #define MD5_A0	0x67452301
 #define MD5_B0	0xefcdab89
 #define MD5_C0	0x98badcfe
 #define MD5_D0	0x10325476

 /* Integer part of 4294967296 times abs(sin(i)), where i is in radians. */
 static const uint32_t T[65] = {
 	0,
 	0xd76aa478, 	0xe8c7b756,	0x242070db,	0xc1bdceee,
 	0xf57c0faf,	0x4787c62a, 	0xa8304613,	0xfd469501,
 	0x698098d8,	0x8b44f7af,	0xffff5bb1,	0x895cd7be,
 	0x6b901122, 	0xfd987193, 	0xa679438e,	0x49b40821,

 	0xf61e2562,	0xc040b340, 	0x265e5a51, 	0xe9b6c7aa,
 	0xd62f105d,	0x2441453,	0xd8a1e681,	0xe7d3fbc8,
 	0x21e1cde6,	0xc33707d6, 	0xf4d50d87, 	0x455a14ed,
 	0xa9e3e905,	0xfcefa3f8, 	0x676f02d9, 	0x8d2a4c8a,

 	0xfffa3942,	0x8771f681, 	0x6d9d6122, 	0xfde5380c,
 	0xa4beea44, 	0x4bdecfa9, 	0xf6bb4b60, 	0xbebfbc70,
 	0x289b7ec6, 	0xeaa127fa, 	0xd4ef3085,	0x4881d05,
 	0xd9d4d039, 	0xe6db99e5, 	0x1fa27cf8, 	0xc4ac5665,

 	0xf4292244, 	0x432aff97, 	0xab9423a7, 	0xfc93a039,
 	0x655b59c3, 	0x8f0ccc92, 	0xffeff47d, 	0x85845dd1,
 	0x6fa87e4f, 	0xfe2ce6e0, 	0xa3014314, 	0x4e0811a1,
 	0xf7537e82, 	0xbd3af235, 	0x2ad7d2bb, 	0xeb86d391,
 };

 static const uint8_t md5_paddat[MD5_BUFLEN] = {
 	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,
 };

 static void md5_calc (const uint8_t *, md5_ctxt *);

 void md5_init(md5_ctxt *ctxt)
 {
 	ctxt->md5_n = 0;
 	ctxt->md5_i = 0;
 	ctxt->md5_sta = MD5_A0;
 	ctxt->md5_stb = MD5_B0;
 	ctxt->md5_stc = MD5_C0;
 	ctxt->md5_std = MD5_D0;
 	memset (ctxt->md5_buf, 0, sizeof(ctxt->md5_buf));
 }

 void md5_loop(md5_ctxt *ctxt, const void *vinput, uint len)
 {
 	uint gap, i;
 	const uint8_t *input = vinput;

 	ctxt->md5_n += len * 8; /* byte to bit */
 	gap = MD5_BUFLEN - ctxt->md5_i;

 	if (len >= gap) {
 		memcpy (ctxt->md5_buf + ctxt->md5_i, input, gap);
 		md5_calc(ctxt->md5_buf, ctxt);

 		for (i = gap; i + MD5_BUFLEN <= len; i += MD5_BUFLEN) {
 			md5_calc((input + i), ctxt);
 		}

 		ctxt->md5_i = len - i;
 		memcpy (ctxt->md5_buf, (input + i), ctxt->md5_i);
 	} else {
 		memcpy (ctxt->md5_buf + ctxt->md5_i, input, len);
 		ctxt->md5_i += len;
 	}
 }

 void md5_pad(md5_ctxt *ctxt)
 {
 	uint gap;

 	/* Don't count up padding. Keep md5_n. */
 	gap = MD5_BUFLEN - ctxt->md5_i;
 	if (gap > 8) {
 		memcpy (ctxt->md5_buf + ctxt->md5_i, md5_paddat,
 			gap - sizeof(ctxt->md5_n));
 	} else {
 		/* including gap == 8 */
 		memcpy (ctxt->md5_buf + ctxt->md5_i, md5_paddat, gap);
 		md5_calc (ctxt->md5_buf, ctxt);
 		memcpy (ctxt->md5_buf, md5_paddat + gap,
 			MD5_BUFLEN - sizeof(ctxt->md5_n));
 	}

 	/* 8 byte word */
 	if (BYTE_ORDER == LITTLE_ENDIAN)
 	  memcpy (&ctxt->md5_buf[56], &ctxt->md5_n8[0], 8);
 	else
 	  {
 	    ctxt->md5_buf[56] = ctxt->md5_n8[7];
 	    ctxt->md5_buf[57] = ctxt->md5_n8[6];
 	    ctxt->md5_buf[58] = ctxt->md5_n8[5];
 	    ctxt->md5_buf[59] = ctxt->md5_n8[4];
 	    ctxt->md5_buf[60] = ctxt->md5_n8[3];
 	    ctxt->md5_buf[61] = ctxt->md5_n8[2];
 	    ctxt->md5_buf[62] = ctxt->md5_n8[1];
 	    ctxt->md5_buf[63] = ctxt->md5_n8[0];
 	  }
 	md5_calc(ctxt->md5_buf, ctxt);
 }

 void md5_result(uint8_t *digest, md5_ctxt *ctxt)
 {
 	/* 4 byte words */
 	if (BYTE_ORDER == LITTLE_ENDIAN)
 	  memcpy (digest, &ctxt->md5_st8[0], 16);
 	else if (BYTE_ORDER == BIG_ENDIAN)
 	  {
 	    digest[ 0] = ctxt->md5_st8[ 3]; digest[ 1] = ctxt->md5_st8[ 2];
 	    digest[ 2] = ctxt->md5_st8[ 1]; digest[ 3] = ctxt->md5_st8[ 0];
 	    digest[ 4] = ctxt->md5_st8[ 7]; digest[ 5] = ctxt->md5_st8[ 6];
 	    digest[ 6] = ctxt->md5_st8[ 5]; digest[ 7] = ctxt->md5_st8[ 4];
 	    digest[ 8] = ctxt->md5_st8[11]; digest[ 9] = ctxt->md5_st8[10];
 	    digest[10] = ctxt->md5_st8[ 9]; digest[11] = ctxt->md5_st8[ 8];
 	    digest[12] = ctxt->md5_st8[15]; digest[13] = ctxt->md5_st8[14];
 	    digest[14] = ctxt->md5_st8[13]; digest[15] = ctxt->md5_st8[12];
 	  }
 }

 static void md5_calc(const uint8_t *b64, md5_ctxt * ctxt)
 {
 	uint32_t A = ctxt->md5_sta;
 	uint32_t B = ctxt->md5_stb;
 	uint32_t C = ctxt->md5_stc;
 	uint32_t D = ctxt->md5_std;
 #if (BYTE_ORDER == LITTLE_ENDIAN)
 	const uint32_t *X = (const uint32_t *)b64;
 #elif (BYTE_ORDER == BIG_ENDIAN)
 	uint32_t X[16];

 	if (BYTE_ORDER == BIG_ENDIAN)
 	  {
 	    /* 4 byte words */
 	    /* what a brute force but fast! */
 	    uint8_t *y = (uint8_t *)X;
 	    y[ 0] = b64[ 3]; y[ 1] = b64[ 2]; y[ 2] = b64[ 1]; y[ 3] = b64[ 0];
 	    y[ 4] = b64[ 7]; y[ 5] = b64[ 6]; y[ 6] = b64[ 5]; y[ 7] = b64[ 4];
 	    y[ 8] = b64[11]; y[ 9] = b64[10]; y[10] = b64[ 9]; y[11] = b64[ 8];
 	    y[12] = b64[15]; y[13] = b64[14]; y[14] = b64[13]; y[15] = b64[12];
 	    y[16] = b64[19]; y[17] = b64[18]; y[18] = b64[17]; y[19] = b64[16];
 	    y[20] = b64[23]; y[21] = b64[22]; y[22] = b64[21]; y[23] = b64[20];
 	    y[24] = b64[27]; y[25] = b64[26]; y[26] = b64[25]; y[27] = b64[24];
 	    y[28] = b64[31]; y[29] = b64[30]; y[30] = b64[29]; y[31] = b64[28];
 	    y[32] = b64[35]; y[33] = b64[34]; y[34] = b64[33]; y[35] = b64[32];
 	    y[36] = b64[39]; y[37] = b64[38]; y[38] = b64[37]; y[39] = b64[36];
 	    y[40] = b64[43]; y[41] = b64[42]; y[42] = b64[41]; y[43] = b64[40];
 	    y[44] = b64[47]; y[45] = b64[46]; y[46] = b64[45]; y[47] = b64[44];
 	    y[48] = b64[51]; y[49] = b64[50]; y[50] = b64[49]; y[51] = b64[48];
 	    y[52] = b64[55]; y[53] = b64[54]; y[54] = b64[53]; y[55] = b64[52];
 	    y[56] = b64[59]; y[57] = b64[58]; y[58] = b64[57]; y[59] = b64[56];
 	    y[60] = b64[63]; y[61] = b64[62]; y[62] = b64[61]; y[63] = b64[60];
 	  }
 #endif

 	ROUND1(A, B, C, D,  0, Sa,  1); ROUND1(D, A, B, C,  1, Sb,  2);
 	ROUND1(C, D, A, B,  2, Sc,  3); ROUND1(B, C, D, A,  3, Sd,  4);
 	ROUND1(A, B, C, D,  4, Sa,  5); ROUND1(D, A, B, C,  5, Sb,  6);
 	ROUND1(C, D, A, B,  6, Sc,  7); ROUND1(B, C, D, A,  7, Sd,  8);
 	ROUND1(A, B, C, D,  8, Sa,  9); ROUND1(D, A, B, C,  9, Sb, 10);
 	ROUND1(C, D, A, B, 10, Sc, 11); ROUND1(B, C, D, A, 11, Sd, 12);
 	ROUND1(A, B, C, D, 12, Sa, 13); ROUND1(D, A, B, C, 13, Sb, 14);
 	ROUND1(C, D, A, B, 14, Sc, 15); ROUND1(B, C, D, A, 15, Sd, 16);

 	ROUND2(A, B, C, D,  1, Se, 17); ROUND2(D, A, B, C,  6, Sf, 18);
 	ROUND2(C, D, A, B, 11, Sg, 19); ROUND2(B, C, D, A,  0, Sh, 20);
 	ROUND2(A, B, C, D,  5, Se, 21); ROUND2(D, A, B, C, 10, Sf, 22);
 	ROUND2(C, D, A, B, 15, Sg, 23); ROUND2(B, C, D, A,  4, Sh, 24);
 	ROUND2(A, B, C, D,  9, Se, 25); ROUND2(D, A, B, C, 14, Sf, 26);
 	ROUND2(C, D, A, B,  3, Sg, 27); ROUND2(B, C, D, A,  8, Sh, 28);
 	ROUND2(A, B, C, D, 13, Se, 29); ROUND2(D, A, B, C,  2, Sf, 30);
 	ROUND2(C, D, A, B,  7, Sg, 31); ROUND2(B, C, D, A, 12, Sh, 32);

 	ROUND3(A, B, C, D,  5, Si, 33); ROUND3(D, A, B, C,  8, Sj, 34);
 	ROUND3(C, D, A, B, 11, Sk, 35); ROUND3(B, C, D, A, 14, Sl, 36);
 	ROUND3(A, B, C, D,  1, Si, 37); ROUND3(D, A, B, C,  4, Sj, 38);
 	ROUND3(C, D, A, B,  7, Sk, 39); ROUND3(B, C, D, A, 10, Sl, 40);
 	ROUND3(A, B, C, D, 13, Si, 41); ROUND3(D, A, B, C,  0, Sj, 42);
 	ROUND3(C, D, A, B,  3, Sk, 43); ROUND3(B, C, D, A,  6, Sl, 44);
 	ROUND3(A, B, C, D,  9, Si, 45); ROUND3(D, A, B, C, 12, Sj, 46);
 	ROUND3(C, D, A, B, 15, Sk, 47); ROUND3(B, C, D, A,  2, Sl, 48);

 	ROUND4(A, B, C, D,  0, Sm, 49); ROUND4(D, A, B, C,  7, Sn, 50);
 	ROUND4(C, D, A, B, 14, So, 51); ROUND4(B, C, D, A,  5, Sp, 52);
 	ROUND4(A, B, C, D, 12, Sm, 53); ROUND4(D, A, B, C,  3, Sn, 54);
 	ROUND4(C, D, A, B, 10, So, 55); ROUND4(B, C, D, A,  1, Sp, 56);
 	ROUND4(A, B, C, D,  8, Sm, 57); ROUND4(D, A, B, C, 15, Sn, 58);
 	ROUND4(C, D, A, B,  6, So, 59); ROUND4(B, C, D, A, 13, Sp, 60);
 	ROUND4(A, B, C, D,  4, Sm, 61); ROUND4(D, A, B, C, 11, Sn, 62);
 	ROUND4(C, D, A, B,  2, So, 63); ROUND4(B, C, D, A,  9, Sp, 64);

 	ctxt->md5_sta += A;
 	ctxt->md5_stb += B;
 	ctxt->md5_stc += C;
 	ctxt->md5_std += D;
 }
	/* $USAGI: md5.c,v 1.2 2000/11/02 11:59:24 yoshfuji Exp $ */
	/* $KAME: md5.c,v 1.2 2000/05/27 07:07:48 jinmei Exp $ */
	/* $Id: md5.c,v 1.6 2006/01/17 23:39:04 vincent Exp $ */

	/*
	* Copyright (C) 2004 6WIND
	* <Vincent.Jardin@6WIND.com>
	* All rights reserved.
	*
	* This MD5 code is Big endian and Little Endian compatible.
	*/

	/*
	* 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.
	*/

	#include <zebra.h>
	#include "md5.h"

	#define SHIFT(X, s) (((X) << (s)) \| ((X) >> (32 - (s))))

	#define F(X, Y, Z) (((X) & (Y)) \| ((~X) & (Z)))
	#define G(X, Y, Z) (((X) & (Z)) \| ((Y) & (~Z)))
	#define H(X, Y, Z) ((X) ^ (Y) ^ (Z))
	#define I(X, Y, Z) ((Y) ^ ((X) \| (~Z)))

	#define ROUND1(a, b, c, d, k, s, i) { \
	(a) = (a) + F((b), (c), (d)) + X[(k)] + T[(i)]; \
	(a) = SHIFT((a), (s)); \
	(a) = (b) + (a); \
	}

	#define ROUND2(a, b, c, d, k, s, i) { \
	(a) = (a) + G((b), (c), (d)) + X[(k)] + T[(i)]; \
	(a) = SHIFT((a), (s)); \
	(a) = (b) + (a); \
	}

	#define ROUND3(a, b, c, d, k, s, i) { \
	(a) = (a) + H((b), (c), (d)) + X[(k)] + T[(i)]; \
	(a) = SHIFT((a), (s)); \
	(a) = (b) + (a); \
	}

	#define ROUND4(a, b, c, d, k, s, i) { \
	(a) = (a) + I((b), (c), (d)) + X[(k)] + T[(i)]; \
	(a) = SHIFT((a), (s)); \
	(a) = (b) + (a); \
	}

	#define Sa 7
	#define Sb 12
	#define Sc 17
	#define Sd 22

	#define Se 5
	#define Sf 9
	#define Sg 14
	#define Sh 20

	#define Si 4
	#define Sj 11
	#define Sk 16
	#define Sl 23

	#define Sm 6
	#define Sn 10
	#define So 15
	#define Sp 21

	#define MD5_A0 0x67452301
	#define MD5_B0 0xefcdab89
	#define MD5_C0 0x98badcfe
	#define MD5_D0 0x10325476

	/* Integer part of 4294967296 times abs(sin(i)), where i is in radians. */
	static const uint32_t T[65] = {
	0,
	0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee,
	0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501,
	0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
	0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821,

	0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa,
	0xd62f105d, 0x2441453, 0xd8a1e681, 0xe7d3fbc8,
	0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed,
	0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a,

	0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c,
	0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70,
	0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x4881d05,
	0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,

	0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039,
	0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1,
	0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
	0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391,
	};

	static const uint8_t md5_paddat[MD5_BUFLEN] = {
	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,
	};

	static void md5_calc (const uint8_t , md5_ctxt );

	void md5_init(md5_ctxt *ctxt)
	{
	ctxt->md5_n = 0;
	ctxt->md5_i = 0;
	ctxt->md5_sta = MD5_A0;
	ctxt->md5_stb = MD5_B0;
	ctxt->md5_stc = MD5_C0;
	ctxt->md5_std = MD5_D0;
	memset (ctxt->md5_buf, 0, sizeof(ctxt->md5_buf));
	}

	void md5_loop(md5_ctxt ctxt, const void vinput, uint len)
	{
	uint gap, i;
	const uint8_t *input = vinput;

	ctxt->md5_n += len * 8; /* byte to bit */
	gap = MD5_BUFLEN - ctxt->md5_i;

	if (len >= gap) {
	memcpy (ctxt->md5_buf + ctxt->md5_i, input, gap);
	md5_calc(ctxt->md5_buf, ctxt);

	for (i = gap; i + MD5_BUFLEN <= len; i += MD5_BUFLEN) {
	md5_calc((input + i), ctxt);
	}

	ctxt->md5_i = len - i;
	memcpy (ctxt->md5_buf, (input + i), ctxt->md5_i);
	} else {
	memcpy (ctxt->md5_buf + ctxt->md5_i, input, len);
	ctxt->md5_i += len;
	}
	}

	void md5_pad(md5_ctxt *ctxt)
	{
	uint gap;

	/* Don't count up padding. Keep md5_n. */
	gap = MD5_BUFLEN - ctxt->md5_i;
	if (gap > 8) {
	memcpy (ctxt->md5_buf + ctxt->md5_i, md5_paddat,
	gap - sizeof(ctxt->md5_n));
	} else {
	/* including gap == 8 */
	memcpy (ctxt->md5_buf + ctxt->md5_i, md5_paddat, gap);
	md5_calc (ctxt->md5_buf, ctxt);
	memcpy (ctxt->md5_buf, md5_paddat + gap,
	MD5_BUFLEN - sizeof(ctxt->md5_n));
	}

	/* 8 byte word */
	if (BYTE_ORDER == LITTLE_ENDIAN)
	memcpy (&ctxt->md5_buf[56], &ctxt->md5_n8[0], 8);
	else
	{
	ctxt->md5_buf[56] = ctxt->md5_n8[7];
	ctxt->md5_buf[57] = ctxt->md5_n8[6];
	ctxt->md5_buf[58] = ctxt->md5_n8[5];
	ctxt->md5_buf[59] = ctxt->md5_n8[4];
	ctxt->md5_buf[60] = ctxt->md5_n8[3];
	ctxt->md5_buf[61] = ctxt->md5_n8[2];
	ctxt->md5_buf[62] = ctxt->md5_n8[1];
	ctxt->md5_buf[63] = ctxt->md5_n8[0];
	}
	md5_calc(ctxt->md5_buf, ctxt);
	}

	void md5_result(uint8_t digest, md5_ctxt ctxt)
	{
	/* 4 byte words */
	if (BYTE_ORDER == LITTLE_ENDIAN)
	memcpy (digest, &ctxt->md5_st8[0], 16);
	else if (BYTE_ORDER == BIG_ENDIAN)
	{
	digest[ 0] = ctxt->md5_st8[ 3]; digest[ 1] = ctxt->md5_st8[ 2];
	digest[ 2] = ctxt->md5_st8[ 1]; digest[ 3] = ctxt->md5_st8[ 0];
	digest[ 4] = ctxt->md5_st8[ 7]; digest[ 5] = ctxt->md5_st8[ 6];
	digest[ 6] = ctxt->md5_st8[ 5]; digest[ 7] = ctxt->md5_st8[ 4];
	digest[ 8] = ctxt->md5_st8[11]; digest[ 9] = ctxt->md5_st8[10];
	digest[10] = ctxt->md5_st8[ 9]; digest[11] = ctxt->md5_st8[ 8];
	digest[12] = ctxt->md5_st8[15]; digest[13] = ctxt->md5_st8[14];
	digest[14] = ctxt->md5_st8[13]; digest[15] = ctxt->md5_st8[12];
	}
	}

	static void md5_calc(const uint8_t b64, md5_ctxt ctxt)
	{
	uint32_t A = ctxt->md5_sta;
	uint32_t B = ctxt->md5_stb;
	uint32_t C = ctxt->md5_stc;
	uint32_t D = ctxt->md5_std;
	#if (BYTE_ORDER == LITTLE_ENDIAN)
	const uint32_t X = (const uint32_t )b64;
	#elif (BYTE_ORDER == BIG_ENDIAN)
	uint32_t X[16];

	if (BYTE_ORDER == BIG_ENDIAN)
	{
	/* 4 byte words */
	/* what a brute force but fast! */
	uint8_t y = (uint8_t )X;
	y[ 0] = b64[ 3]; y[ 1] = b64[ 2]; y[ 2] = b64[ 1]; y[ 3] = b64[ 0];
	y[ 4] = b64[ 7]; y[ 5] = b64[ 6]; y[ 6] = b64[ 5]; y[ 7] = b64[ 4];
	y[ 8] = b64[11]; y[ 9] = b64[10]; y[10] = b64[ 9]; y[11] = b64[ 8];
	y[12] = b64[15]; y[13] = b64[14]; y[14] = b64[13]; y[15] = b64[12];
	y[16] = b64[19]; y[17] = b64[18]; y[18] = b64[17]; y[19] = b64[16];
	y[20] = b64[23]; y[21] = b64[22]; y[22] = b64[21]; y[23] = b64[20];
	y[24] = b64[27]; y[25] = b64[26]; y[26] = b64[25]; y[27] = b64[24];
	y[28] = b64[31]; y[29] = b64[30]; y[30] = b64[29]; y[31] = b64[28];
	y[32] = b64[35]; y[33] = b64[34]; y[34] = b64[33]; y[35] = b64[32];
	y[36] = b64[39]; y[37] = b64[38]; y[38] = b64[37]; y[39] = b64[36];
	y[40] = b64[43]; y[41] = b64[42]; y[42] = b64[41]; y[43] = b64[40];
	y[44] = b64[47]; y[45] = b64[46]; y[46] = b64[45]; y[47] = b64[44];
	y[48] = b64[51]; y[49] = b64[50]; y[50] = b64[49]; y[51] = b64[48];
	y[52] = b64[55]; y[53] = b64[54]; y[54] = b64[53]; y[55] = b64[52];
	y[56] = b64[59]; y[57] = b64[58]; y[58] = b64[57]; y[59] = b64[56];
	y[60] = b64[63]; y[61] = b64[62]; y[62] = b64[61]; y[63] = b64[60];
	}
	#endif

	ROUND1(A, B, C, D, 0, Sa, 1); ROUND1(D, A, B, C, 1, Sb, 2);
	ROUND1(C, D, A, B, 2, Sc, 3); ROUND1(B, C, D, A, 3, Sd, 4);
	ROUND1(A, B, C, D, 4, Sa, 5); ROUND1(D, A, B, C, 5, Sb, 6);
	ROUND1(C, D, A, B, 6, Sc, 7); ROUND1(B, C, D, A, 7, Sd, 8);
	ROUND1(A, B, C, D, 8, Sa, 9); ROUND1(D, A, B, C, 9, Sb, 10);
	ROUND1(C, D, A, B, 10, Sc, 11); ROUND1(B, C, D, A, 11, Sd, 12);
	ROUND1(A, B, C, D, 12, Sa, 13); ROUND1(D, A, B, C, 13, Sb, 14);
	ROUND1(C, D, A, B, 14, Sc, 15); ROUND1(B, C, D, A, 15, Sd, 16);

	ROUND2(A, B, C, D, 1, Se, 17); ROUND2(D, A, B, C, 6, Sf, 18);
	ROUND2(C, D, A, B, 11, Sg, 19); ROUND2(B, C, D, A, 0, Sh, 20);
	ROUND2(A, B, C, D, 5, Se, 21); ROUND2(D, A, B, C, 10, Sf, 22);
	ROUND2(C, D, A, B, 15, Sg, 23); ROUND2(B, C, D, A, 4, Sh, 24);
	ROUND2(A, B, C, D, 9, Se, 25); ROUND2(D, A, B, C, 14, Sf, 26);
	ROUND2(C, D, A, B, 3, Sg, 27); ROUND2(B, C, D, A, 8, Sh, 28);
	ROUND2(A, B, C, D, 13, Se, 29); ROUND2(D, A, B, C, 2, Sf, 30);
	ROUND2(C, D, A, B, 7, Sg, 31); ROUND2(B, C, D, A, 12, Sh, 32);

	ROUND3(A, B, C, D, 5, Si, 33); ROUND3(D, A, B, C, 8, Sj, 34);
	ROUND3(C, D, A, B, 11, Sk, 35); ROUND3(B, C, D, A, 14, Sl, 36);
	ROUND3(A, B, C, D, 1, Si, 37); ROUND3(D, A, B, C, 4, Sj, 38);
	ROUND3(C, D, A, B, 7, Sk, 39); ROUND3(B, C, D, A, 10, Sl, 40);
	ROUND3(A, B, C, D, 13, Si, 41); ROUND3(D, A, B, C, 0, Sj, 42);
	ROUND3(C, D, A, B, 3, Sk, 43); ROUND3(B, C, D, A, 6, Sl, 44);
	ROUND3(A, B, C, D, 9, Si, 45); ROUND3(D, A, B, C, 12, Sj, 46);
	ROUND3(C, D, A, B, 15, Sk, 47); ROUND3(B, C, D, A, 2, Sl, 48);

	ROUND4(A, B, C, D, 0, Sm, 49); ROUND4(D, A, B, C, 7, Sn, 50);
	ROUND4(C, D, A, B, 14, So, 51); ROUND4(B, C, D, A, 5, Sp, 52);
	ROUND4(A, B, C, D, 12, Sm, 53); ROUND4(D, A, B, C, 3, Sn, 54);
	ROUND4(C, D, A, B, 10, So, 55); ROUND4(B, C, D, A, 1, Sp, 56);
	ROUND4(A, B, C, D, 8, Sm, 57); ROUND4(D, A, B, C, 15, Sn, 58);
	ROUND4(C, D, A, B, 6, So, 59); ROUND4(B, C, D, A, 13, Sp, 60);
	ROUND4(A, B, C, D, 4, Sm, 61); ROUND4(D, A, B, C, 11, Sn, 62);
	ROUND4(C, D, A, B, 2, So, 63); ROUND4(B, C, D, A, 9, Sp, 64);

	ctxt->md5_sta += A;
	ctxt->md5_stb += B;
	ctxt->md5_stc += C;
	ctxt->md5_std += D;
	}