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/*
mdfour.c
An implementation of MD4 designed for use in the samba SMB
authentication protocol
Copyright (C) 1997-1998 Andrew Tridgell
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
of the License, 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:
Free Software Foundation, Inc.
59 Temple Place - Suite 330
Boston, MA 02111-1307, USA
$Id: mdfour.c,v 1.1 2002/08/23 22:03:27 abster Exp $
*/
#include "q_shared.h"
#include "qcommon.h"
struct mdfour {
uint32_t A, B, C, D;
uint32_t totalN;
};
/* NOTE: This code makes no attempt to be fast!
It assumes that a int is at least 32 bits long
*/
static struct mdfour *m;
#define F(X,Y,Z) (((X)&(Y)) | ((~(X))&(Z)))
#define G(X,Y,Z) (((X)&(Y)) | ((X)&(Z)) | ((Y)&(Z)))
#define H(X,Y,Z) ((X)^(Y)^(Z))
#define lshift(x,s) (((x)<<(s)) | ((x)>>(32-(s))))
#define ROUND1(a,b,c,d,k,s) a = lshift(a + F(b,c,d) + X[k], s)
#define ROUND2(a,b,c,d,k,s) a = lshift(a + G(b,c,d) + X[k] + 0x5A827999,s)
#define ROUND3(a,b,c,d,k,s) a = lshift(a + H(b,c,d) + X[k] + 0x6ED9EBA1,s)
/* this applies md4 to 64 byte chunks */
static void mdfour64(uint32_t *M)
{
int j;
uint32_t AA, BB, CC, DD;
uint32_t X[16];
uint32_t A,B,C,D;
for (j=0;j<16;j++)
X[j] = M[j];
A = m->A; B = m->B; C = m->C; D = m->D;
AA = A; BB = B; CC = C; DD = D;
ROUND1(A,B,C,D, 0, 3); ROUND1(D,A,B,C, 1, 7);
ROUND1(C,D,A,B, 2, 11); ROUND1(B,C,D,A, 3, 19);
ROUND1(A,B,C,D, 4, 3); ROUND1(D,A,B,C, 5, 7);
ROUND1(C,D,A,B, 6, 11); ROUND1(B,C,D,A, 7, 19);
ROUND1(A,B,C,D, 8, 3); ROUND1(D,A,B,C, 9, 7);
ROUND1(C,D,A,B, 10, 11); ROUND1(B,C,D,A, 11, 19);
ROUND1(A,B,C,D, 12, 3); ROUND1(D,A,B,C, 13, 7);
ROUND1(C,D,A,B, 14, 11); ROUND1(B,C,D,A, 15, 19);
ROUND2(A,B,C,D, 0, 3); ROUND2(D,A,B,C, 4, 5);
ROUND2(C,D,A,B, 8, 9); ROUND2(B,C,D,A, 12, 13);
ROUND2(A,B,C,D, 1, 3); ROUND2(D,A,B,C, 5, 5);
ROUND2(C,D,A,B, 9, 9); ROUND2(B,C,D,A, 13, 13);
ROUND2(A,B,C,D, 2, 3); ROUND2(D,A,B,C, 6, 5);
ROUND2(C,D,A,B, 10, 9); ROUND2(B,C,D,A, 14, 13);
ROUND2(A,B,C,D, 3, 3); ROUND2(D,A,B,C, 7, 5);
ROUND2(C,D,A,B, 11, 9); ROUND2(B,C,D,A, 15, 13);
ROUND3(A,B,C,D, 0, 3); ROUND3(D,A,B,C, 8, 9);
ROUND3(C,D,A,B, 4, 11); ROUND3(B,C,D,A, 12, 15);
ROUND3(A,B,C,D, 2, 3); ROUND3(D,A,B,C, 10, 9);
ROUND3(C,D,A,B, 6, 11); ROUND3(B,C,D,A, 14, 15);
ROUND3(A,B,C,D, 1, 3); ROUND3(D,A,B,C, 9, 9);
ROUND3(C,D,A,B, 5, 11); ROUND3(B,C,D,A, 13, 15);
ROUND3(A,B,C,D, 3, 3); ROUND3(D,A,B,C, 11, 9);
ROUND3(C,D,A,B, 7, 11); ROUND3(B,C,D,A, 15, 15);
A += AA; B += BB; C += CC; D += DD;
for (j=0;j<16;j++)
X[j] = 0;
m->A = A; m->B = B; m->C = C; m->D = D;
}
static void copy64(uint32_t *M, byte *in)
{
int i;
for (i=0;i<16;i++)
M[i] = (in[i*4+3]<<24) | (in[i*4+2]<<16) |
(in[i*4+1]<<8) | (in[i*4+0]<<0);
}
static void copy4(byte *out,uint32_t x)
{
out[0] = x&0xFF;
out[1] = (x>>8)&0xFF;
out[2] = (x>>16)&0xFF;
out[3] = (x>>24)&0xFF;
}
void mdfour_begin(struct mdfour *md)
{
md->A = 0x67452301;
md->B = 0xefcdab89;
md->C = 0x98badcfe;
md->D = 0x10325476;
md->totalN = 0;
}
static void mdfour_tail(byte *in, int n)
{
byte buf[128];
uint32_t M[16];
uint32_t b;
m->totalN += n;
b = m->totalN * 8;
Com_Memset(buf, 0, 128);
if (n) Com_Memcpy(buf, in, n);
buf[n] = 0x80;
if (n <= 55) {
copy4(buf+56, b);
copy64(M, buf);
mdfour64(M);
} else {
copy4(buf+120, b);
copy64(M, buf);
mdfour64(M);
copy64(M, buf+64);
mdfour64(M);
}
}
static void mdfour_update(struct mdfour *md, byte *in, int n)
{
uint32_t M[16];
m = md;
if (n == 0) mdfour_tail(in, n);
while (n >= 64) {
copy64(M, in);
mdfour64(M);
in += 64;
n -= 64;
m->totalN += 64;
}
mdfour_tail(in, n);
}
static void mdfour_result(struct mdfour *md, byte *out)
{
m = md;
copy4(out, m->A);
copy4(out+4, m->B);
copy4(out+8, m->C);
copy4(out+12, m->D);
}
static void mdfour(byte *out, byte *in, int n)
{
struct mdfour md;
mdfour_begin(&md);
mdfour_update(&md, in, n);
mdfour_result(&md, out);
}
//===================================================================
unsigned Com_BlockChecksum (const void *buffer, int length)
{
int digest[4];
unsigned val;
mdfour( (byte *)digest, (byte *)buffer, length );
val = digest[0] ^ digest[1] ^ digest[2] ^ digest[3];
return val;
}
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