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/* md4.c - MD4 Message-Digest Algorithm
* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
*
* This file is part of Libgcrypt.
*
* Libgcrypt is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* Libgcrypt 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.
*
* You should have received a copy of the GNU Lesser 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
*
* Based on md5.c in libgcrypt, but rewritten to compute md4 checksums
* using a public domain md4 implementation with the following comments:
*
* Modified by Wei Dai from Andrew M. Kuchling's md4.c
* The original code and all modifications are in the public domain.
*
* This is the original introductory comment:
*
* md4.c : MD4 hash algorithm.
*
* Part of the Python Cryptography Toolkit, version 1.1
*
* Distribute and use freely; there are no restrictions on further
* dissemination and usage except those imposed by the laws of your
* country of residence.
*
*/
/* MD4 test suite:
* MD4 ("") = 31d6cfe0d16ae931b73c59d7e0c089c0
* MD4 ("a") = bde52cb31de33e46245e05fbdbd6fb24
* MD4 ("abc") = a448017aaf21d8525fc10ae87aa6729d
* MD4 ("message digest") = d9130a8164549fe818874806e1c7014b
* MD4 ("abcdefghijklmnopqrstuvwxyz") = d79e1c308aa5bbcdeea8ed63df412da9
* MD4 ("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789") =
* 043f8582f241db351ce627e153e7f0e4
* MD4 ("123456789012345678901234567890123456789012345678901234567890123456
* 78901234567890") = e33b4ddc9c38f2199c3e7b164fcc0536
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "g10lib.h"
#include "cipher.h"
#include "bithelp.h"
typedef struct {
u32 A,B,C,D; /* chaining variables */
u32 nblocks;
byte buf[64];
int count;
} MD4_CONTEXT;
static void
md4_init( void *context )
{
MD4_CONTEXT *ctx = context;
ctx->A = 0x67452301;
ctx->B = 0xefcdab89;
ctx->C = 0x98badcfe;
ctx->D = 0x10325476;
ctx->nblocks = 0;
ctx->count = 0;
}
#define F(x, y, z) ((z) ^ ((x) & ((y) ^ (z))))
#define G(x, y, z) (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
/****************
* transform 64 bytes
*/
static void
transform ( MD4_CONTEXT *ctx, const unsigned char *data )
{
u32 in[16];
register u32 A = ctx->A;
register u32 B = ctx->B;
register u32 C = ctx->C;
register u32 D = ctx->D;
#ifdef WORDS_BIGENDIAN
{
int i;
byte *p2, *p1;
for(i=0, p1=data, p2=(byte*)in; i < 16; i++, p2 += 4 )
{
p2[3] = *p1++;
p2[2] = *p1++;
p2[1] = *p1++;
p2[0] = *p1++;
}
}
#else
memcpy (in, data, 64);
#endif
/* Round 1. */
#define function(a,b,c,d,k,s) a=rol(a+F(b,c,d)+in[k],s);
function(A,B,C,D, 0, 3);
function(D,A,B,C, 1, 7);
function(C,D,A,B, 2,11);
function(B,C,D,A, 3,19);
function(A,B,C,D, 4, 3);
function(D,A,B,C, 5, 7);
function(C,D,A,B, 6,11);
function(B,C,D,A, 7,19);
function(A,B,C,D, 8, 3);
function(D,A,B,C, 9, 7);
function(C,D,A,B,10,11);
function(B,C,D,A,11,19);
function(A,B,C,D,12, 3);
function(D,A,B,C,13, 7);
function(C,D,A,B,14,11);
function(B,C,D,A,15,19);
#undef function
/* Round 2. */
#define function(a,b,c,d,k,s) a=rol(a+G(b,c,d)+in[k]+0x5a827999,s);
function(A,B,C,D, 0, 3);
function(D,A,B,C, 4, 5);
function(C,D,A,B, 8, 9);
function(B,C,D,A,12,13);
function(A,B,C,D, 1, 3);
function(D,A,B,C, 5, 5);
function(C,D,A,B, 9, 9);
function(B,C,D,A,13,13);
function(A,B,C,D, 2, 3);
function(D,A,B,C, 6, 5);
function(C,D,A,B,10, 9);
function(B,C,D,A,14,13);
function(A,B,C,D, 3, 3);
function(D,A,B,C, 7, 5);
function(C,D,A,B,11, 9);
function(B,C,D,A,15,13);
#undef function
/* Round 3. */
#define function(a,b,c,d,k,s) a=rol(a+H(b,c,d)+in[k]+0x6ed9eba1,s);
function(A,B,C,D, 0, 3);
function(D,A,B,C, 8, 9);
function(C,D,A,B, 4,11);
function(B,C,D,A,12,15);
function(A,B,C,D, 2, 3);
function(D,A,B,C,10, 9);
function(C,D,A,B, 6,11);
function(B,C,D,A,14,15);
function(A,B,C,D, 1, 3);
function(D,A,B,C, 9, 9);
function(C,D,A,B, 5,11);
function(B,C,D,A,13,15);
function(A,B,C,D, 3, 3);
function(D,A,B,C,11, 9);
function(C,D,A,B, 7,11);
function(B,C,D,A,15,15);
/* 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.
*/
static void
md4_write ( void *context, const void *inbuf_arg, size_t inlen)
{
const unsigned char *inbuf = inbuf_arg;
MD4_CONTEXT *hd = context;
if( hd->count == 64 ) /* flush the buffer */
{
transform( hd, hd->buf );
_gcry_burn_stack (80+6*sizeof(void*));
hd->count = 0;
hd->nblocks++;
}
if( !inbuf )
return;
if( hd->count )
{
for( ; inlen && hd->count < 64; inlen-- )
hd->buf[hd->count++] = *inbuf++;
md4_write( hd, NULL, 0 );
if( !inlen )
return;
}
_gcry_burn_stack (80+6*sizeof(void*));
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 MD4 cycle.
* Returns 16 bytes representing the digest.
*/
static void
md4_final( void *context )
{
MD4_CONTEXT *hd = context;
u32 t, msb, lsb;
byte *p;
md4_write(hd, NULL, 0); /* flush */;
t = hd->nblocks;
/* multiply by 64 to make a byte count */
lsb = t << 6;
msb = t >> 26;
/* add the count */
t = lsb;
if( (lsb += hd->count) < t )
msb++;
/* multiply by 8 to make a bit count */
t = lsb;
lsb <<= 3;
msb <<= 3;
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;
md4_write(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 );
_gcry_burn_stack (80+6*sizeof(void*));
p = hd->buf;
#ifdef WORDS_BIGENDIAN
#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)
#endif
X(A);
X(B);
X(C);
X(D);
#undef X
}
static byte *
md4_read (void *context)
{
MD4_CONTEXT *hd = context;
return hd->buf;
}
static byte asn[18] = /* Object ID is 1.2.840.113549.2.4 */
{ 0x30, 0x20, 0x30, 0x0c, 0x06, 0x08, 0x2a, 0x86,0x48,
0x86, 0xf7, 0x0d, 0x02, 0x04, 0x05, 0x00, 0x04, 0x10 };
static gcry_md_oid_spec_t oid_spec_md4[] =
{
/* iso.member-body.us.rsadsi.digestAlgorithm.md4 */
{ "1.2.840.113549.2.4" },
{ NULL },
};
gcry_md_spec_t _gcry_digest_spec_md4 =
{
"MD4", asn, DIM (asn), oid_spec_md4,16,
md4_init, md4_write, md4_final, md4_read,
sizeof (MD4_CONTEXT)
};

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