/* md5.c - MD5 Message-Digest Algorithm
* Copyright (C) 1995, 1996, 1998, 1999 Free Software Foundation, Inc.
*
* according to the definition of MD5 in RFC 1321 from April 1992.
* NOTE: This is *not* the same file as the one from glibc.
*
* 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.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/* Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995. */
/* heavily modified for GnuPG by <werner.koch@guug.de> */
/* modified again for Sylpheed by <wk@gnupg.org> 2001-02-11 */
/* Test values:
* "" D4 1D 8C D9 8F 00 B2 04 E9 80 09 98 EC F8 42 7E
* "a" 0C C1 75 B9 C0 F1 B6 A8 31 C3 99 E2 69 77 26 61
* "abc 90 01 50 98 3C D2 4F B0 D6 96 3F 7D 28 E1 7F 72
* "message digest" F9 6B 69 7D 7C B7 93 8D 52 5A 2F 31 AA F1 61 D0
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "utils.h"
#include "md5.h"
/****************
* Rotate a 32 bit integer by n bytes
*/
#if defined(__GNUC__) && defined(__i386__)
static inline u32
rol( u32 x, int n)
{
__asm__("roll %%cl,%0"
:"=r" (x)
:"0" (x),"c" (n));
return x;
}
#else
#define rol(x,n) ( ((x) << (n)) | ((x) >> (32-(n))) )
#endif
void
md5_init(MD5_CONTEXT *ctx)
{
ctx->A = 0x67452301;
ctx->B = 0xefcdab89;
ctx->C = 0x98badcfe;
ctx->D = 0x10325476;
ctx->nblocks = 0;
ctx->count = 0;
ctx->finalized = 0;
}
/* These are the four functions used in the four steps of the MD5 algorithm
and defined in the RFC 1321. The first function is a little bit optimized
(as found in Colin Plumbs public domain implementation). */
/* #define FF(b, c, d) ((b & c) | (~b & d)) */
#define FF(b, c, d) (d ^ (b & (c ^ d)))
#define FG(b, c, d) FF (d, b, c)
#define FH(b, c, d) (b ^ c ^ d)
#define FI(b, c, d) (c ^ (b | ~d))
/****************
* transform n*64 bytes
*/
static void
transform(MD5_CONTEXT *ctx, const unsigned char *data)
{
u32 correct_words[16];
u32 A = ctx->A;
u32 B = ctx->B;
u32 C = ctx->C;
u32 D = ctx->D;
u32 *cwp = correct_words;
#ifdef BIG_ENDIAN_HOST
{
int i;
unsigned char *p2, *p1;
for (i = 0, p1 = data, p2 = (unsigned char*)correct_words;
i < 16; i++, p2 += 4) {
p2[3] = *p1++;
p2[2] = *p1++;
p2[1] = *p1++;
p2[0] = *p1++;
}
}
#else
memcpy(correct_words, data, 64);
#endif
#define OP(a, b, c, d, s, T) \
do { \
a += FF (b, c, d) + (*cwp++) + T; \
a = rol(a, s); \
a += b; \
} while (0)
/* Before we start, one word about the strange constants.
They are defined in RFC 1321 as
T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64
*/
/* Round 1. */
OP (A, B, C, D, 7, 0xd76aa478);
OP (D, A, B, C, 12, 0xe8c7b756);
OP (C, D, A, B, 17, 0x242070db);
OP (B, C, D, A, 22, 0xc1bdceee);
OP (A, B, C, D, 7, 0xf57c0faf);
OP (D, A, B, C, 12, 0x4787c62a);
OP (C, D, A, B, 17, 0xa8304613);
OP (B, C, D, A, 22, 0xfd469501);
OP (A, B, C, D, 7, 0x698098d8);
OP (D, A, B, C, 12, 0x8b44f7af);
OP (C, D, A, B, 17, 0xffff5bb1);
OP (B, C, D, A, 22, 0x895cd7be);
OP (A, B, C, D, 7, 0x6b901122);
OP (D, A, B, C, 12, 0xfd987193);
OP (C, D, A, B, 17, 0xa679438e);
OP (B, C, D, A, 22, 0x49b40821);
#undef OP
#define OP(f, a, b, c, d, k, s, T) \
do { \
a += f (b, c, d) + correct_words[k] + T; \
a = rol(a, s); \
a += b; \
} while (0)
/* Round 2. */
OP (FG, A, B, C, D, 1, 5, 0xf61e2562);
OP (FG, D, A, B, C, 6, 9, 0xc040b340);
OP (FG, C, D, A, B, 11, 14, 0x265e5a51);
OP (FG, B, C, D, A, 0, 20, 0xe9b6c7aa);
OP (FG, A, B, C, D, 5, 5, 0xd62f105d);
OP (FG, D, A, B, C, 10, 9, 0x02441453);
OP (FG, C, D, A, B, 15, 14, 0xd8a1e681);
OP (FG, B, C, D, A, 4, 20, 0xe7d3fbc8);
OP (FG, A, B, C, D, 9, 5, 0x21e1cde6);
OP (FG, D, A, B, C, 14, 9, 0xc33707d6);
OP (FG, C, D, A, B, 3, 14, 0xf4d50d87);
OP (FG, B, C, D, A, 8, 20, 0x455a14ed);
OP (FG, A, B, C, D, 13, 5, 0xa9e3e905);
OP (FG, D, A, B, C, 2, 9, 0xfcefa3f8);
OP (FG, C, D, A, B, 7, 14, 0x676f02d9);
OP (FG, B, C, D, A, 12, 20, 0x8d2a4c8a);
/* Round 3. */
OP (FH, A, B, C, D, 5, 4, 0xfffa3942);
OP (FH, D, A, B, C, 8, 11, 0x8771f681);
OP (FH, C, D, A, B, 11, 16, 0x6d9d6122);
OP (FH, B, C, D, A, 14, 23, 0xfde5380c);
OP (FH, A, B, C, D, 1, 4, 0xa4beea44);
OP (FH, D, A, B, C, 4, 11, 0x4bdecfa9);
OP (FH, C, D, A, B, 7, 16, 0xf6bb4b60);
OP (FH, B, C, D, A, 10, 23, 0xbebfbc70);
OP (FH, A, B, C, D, 13, 4, 0x289b7ec6);
OP (FH, D, A, B, C, 0, 11, 0xeaa127fa);
OP (FH, C, D, A, B, 3, 16, 0xd4ef3085);
OP (FH, B, C, D, A, 6, 23, 0x04881d05);
OP (FH, A, B, C, D, 9, 4, 0xd9d4d039);
OP (FH, D, A, B, C, 12, 11, 0xe6db99e5);
OP (FH, C, D, A, B, 15, 16, 0x1fa27cf8);
OP (FH, B, C, D, A, 2, 23, 0xc4ac5665);
/* Round 4. */
OP (FI, A, B, C, D, 0, 6, 0xf4292244);
OP (FI, D, A, B, C, 7, 10, 0x432aff97);
OP (FI, C, D, A, B, 14, 15, 0xab9423a7);
OP (FI, B, C, D, A, 5, 21, 0xfc93a039);
OP (FI, A, B, C, D, 12, 6, 0x655b59c3);
OP (FI, D, A, B, C, 3, 10, 0x8f0ccc92);
OP (FI, C, D, A, B, 10, 15, 0xffeff47d);
OP (FI, B, C, D, A, 1, 21, 0x85845dd1);
OP (FI, A, B, C, D, 8, 6, 0x6fa87e4f);
OP (FI, D, A, B, C, 15, 10, 0xfe2ce6e0);
OP (FI, C, D, A, B, 6, 15, 0xa3014314);
OP (FI, B, C, D, A, 13, 21, 0x4e0811a1);
OP (FI, A, B, C, D, 4, 6, 0xf7537e82);
OP (FI, D, A, B, C, 11, 10, 0xbd3af235);
OP (FI, C, D, A, B, 2, 15, 0x2ad7d2bb);
OP (FI, B, C, D, A, 9, 21, 0xeb86d391);
/* Put checksum in context given as argument. */
ctx->A += A;
ctx->B += B;
ctx->C += C;
ctx->D += D;
}
/* The routine updates the message-digest context to
* account for the presence of each of the characters inBuf[0..inLen-1]
* in the message whose digest is being computed.
*/
void
md5_update(MD5_CONTEXT *hd, const unsigned char *inbuf, size_t inlen)
{
if (hd->count == 64) { /* flush the buffer */
transform( hd, hd->buf );
hd->count = 0;
hd->nblocks++;
}
if (!inbuf)
return;
if (hd->count) {
for (; inlen && hd->count < 64; inlen--)
hd->buf[hd->count++] = *inbuf++;
md5_update(hd, NULL, 0);
if (!inlen)
return;
}
while (inlen >= 64) {
transform(hd, inbuf);
hd->count = 0;
hd->nblocks++;
inlen -= 64;
inbuf += 64;
}
for (; inlen && hd->count < 64; inlen--)
hd->buf[hd->count++] = *inbuf++;
}
/* The routine final terminates the message-digest computation and
* ends with the desired message digest in mdContext->digest[0...15].
* The handle is prepared for a new MD5 cycle.
* Returns 16 bytes representing the digest.
*/
static void
do_final(MD5_CONTEXT *hd)
{
u32 t, msb, lsb;
unsigned char *p;
md5_update(hd, NULL, 0); /* flush */
msb = 0;
t = hd->nblocks;
if ((lsb = t << 6) < t) /* multiply by 64 to make a byte count */
msb++;
msb += t >> 26;
t = lsb;
if ((lsb = t + hd->count) < t) /* add the count */
msb++;
t = lsb;
if ((lsb = t << 3) < t) /* multiply by 8 to make a bit count */
msb++;
msb += t >> 29;
if (hd->count < 56) { /* enough room */
hd->buf[hd->count++] = 0x80; /* pad */
while(hd->count < 56)
hd->buf[hd->count++] = 0; /* pad */
} else { /* need one extra block */
hd->buf[hd->count++] = 0x80; /* pad character */
while (hd->count < 64)
hd->buf[hd->count++] = 0;
md5_update(hd, NULL, 0); /* flush */
memset(hd->buf, 0, 56); /* fill next block with zeroes */
}
/* append the 64 bit count */
hd->buf[56] = lsb ;
hd->buf[57] = lsb >> 8;
hd->buf[58] = lsb >> 16;
hd->buf[59] = lsb >> 24;
hd->buf[60] = msb ;
hd->buf[61] = msb >> 8;
hd->buf[62] = msb >> 16;
hd->buf[63] = msb >> 24;
transform(hd, hd->buf);
p = hd->buf;
#ifdef BIG_ENDIAN_HOST
#define X(a) do { *p++ = hd->a ; *p++ = hd->a >> 8; \
*p++ = hd->a >> 16; *p++ = hd->a >> 24; } while(0)
#else /* little endian */
/*#define X(a) do { *(u32*)p = hd->##a ; p += 4; } while(0)*/
/* Unixware's cpp doesn't like the above construct so we do it his way:
* (reported by Allan Clark) */
#define X(a) do { *(u32*)p = (*hd).a ; p += 4; } while(0)
#endif
X(A);
X(B);
X(C);
X(D);
#undef X
hd->finalized = 1;
}
void
md5_final(unsigned char *digest, MD5_CONTEXT *ctx)
{
if (!ctx->finalized)
do_final(ctx);
memcpy(digest, ctx->buf, 16);
}
/*
* Creates a MD5 digest in hex fomrat (lowercase letters) from the
* string S. hextdigest but be buffer of at lease 33 bytes!
*/
void
md5_hex_digest(char *hexdigest, const unsigned char *s)
{
int i;
MD5_CONTEXT context;
unsigned char digest[16];
md5_init(&context);
md5_update(&context, s, strlen(s));
md5_final(digest, &context);
for (i = 0; i < 16; i++)
sprintf(hexdigest + 2 * i, "%02x", digest[i]);
}
/*
** Function: md5_hmac
** taken from the file rfc2104.txt
** written by Martin Schaaf <mascha@ma-scha.de>
*/
void
md5_hmac(unsigned char *digest,
const unsigned char* text, int text_len,
const unsigned char* key, int key_len)
{
MD5_CONTEXT context;
unsigned char k_ipad[64]; /* inner padding -
* key XORd with ipad
*/
unsigned char k_opad[64]; /* outer padding -
* key XORd with opad
*/
/* unsigned char tk[16]; */
int i;
/* start out by storing key in pads */
memset(k_ipad, 0, sizeof k_ipad);
memset(k_opad, 0, sizeof k_opad);
if (key_len > 64) {
/* if key is longer than 64 bytes reset it to key=MD5(key) */
MD5_CONTEXT tctx;
md5_init(&tctx);
md5_update(&tctx, key, key_len);
md5_final(k_ipad, &tctx);
md5_final(k_opad, &tctx);
} else {
memcpy(k_ipad, key, key_len);
memcpy(k_opad, key, key_len);
}
/*
* the HMAC_MD5 transform looks like:
*
* MD5(K XOR opad, MD5(K XOR ipad, text))
*
* where K is an n byte key
* ipad is the byte 0x36 repeated 64 times
* opad is the byte 0x5c repeated 64 times
* and text is the data being protected
*/
/* XOR key with ipad and opad values */
for (i = 0; i < 64; i++) {
k_ipad[i] ^= 0x36;
k_opad[i] ^= 0x5c;
}
/*
* perform inner MD5
*/
md5_init(&context); /* init context for 1st
* pass */
md5_update(&context, k_ipad, 64); /* start with inner pad */
md5_update(&context, text, text_len); /* then text of datagram */
md5_final(digest, &context); /* finish up 1st pass */
/*
* perform outer MD5
*/
md5_init(&context); /* init context for 2nd
* pass */
md5_update(&context, k_opad, 64); /* start with outer pad */
md5_update(&context, digest, 16); /* then results of 1st
* hash */
md5_final(digest, &context); /* finish up 2nd pass */
}
void
md5_hex_hmac(char *hexdigest,
const unsigned char* text, int text_len,
const unsigned char* key, int key_len)
{
unsigned char digest[16];
int i;
md5_hmac(digest, text, text_len, key, key_len);
for (i = 0; i < 16; i++)
sprintf(hexdigest + 2 * i, "%02x", digest[i]);
}
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