source/lib/md4.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    a implementation of MD4 designed for use in the SMB authentication protocol
   4    Copyright (C) Andrew Tridgell 1997-1998.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 #include "includes.h"
  22
  23 /* NOTE: This code makes no attempt to be fast!
  24
  25    It assumes that a int is at least 32 bits long
  26 */
  27
  28 static uint32 A, B, C, D;
  29
  30 static uint32 F(uint32 X, uint32 Y, uint32 Z)
  31 {
  32         return (X&Y) | ((~X)&Z);
  33 }
  34
  35 static uint32 G(uint32 X, uint32 Y, uint32 Z)
  36 {
  37         return (X&Y) | (X&Z) | (Y&Z);
  38 }
  39
  40 static uint32 H(uint32 X, uint32 Y, uint32 Z)
  41 {
  42         return X^Y^Z;
  43 }
  44
  45 static uint32 lshift(uint32 x, int s)
  46 {
  47         x &= 0xFFFFFFFF;
  48         return ((x<<s)&0xFFFFFFFF) | (x>>(32-s));
  49 }
  50
  51 #define ROUND1(a,b,c,d,k,s) a = lshift(a + F(b,c,d) + X[k], s)
  52 #define ROUND2(a,b,c,d,k,s) a = lshift(a + G(b,c,d) + X[k] + (uint32)0x5A827999,s)
  53 #define ROUND3(a,b,c,d,k,s) a = lshift(a + H(b,c,d) + X[k] + (uint32)0x6ED9EBA1,s)
  54
  55 /* this applies md4 to 64 byte chunks */
  56 static void mdfour64(uint32 *M)
  57 {
  58         int j;
  59         uint32 AA, BB, CC, DD;
  60         uint32 X[16];
  61
  62         for (j=0;j<16;j++)
  63                 X[j] = M[j];
  64
  65         AA = A; BB = B; CC = C; DD = D;
  66
  67         ROUND1(A,B,C,D,  0,  3);  ROUND1(D,A,B,C,  1,  7);
  68         ROUND1(C,D,A,B,  2, 11);  ROUND1(B,C,D,A,  3, 19);
  69         ROUND1(A,B,C,D,  4,  3);  ROUND1(D,A,B,C,  5,  7);
  70         ROUND1(C,D,A,B,  6, 11);  ROUND1(B,C,D,A,  7, 19);
  71         ROUND1(A,B,C,D,  8,  3);  ROUND1(D,A,B,C,  9,  7);
  72         ROUND1(C,D,A,B, 10, 11);  ROUND1(B,C,D,A, 11, 19);
  73         ROUND1(A,B,C,D, 12,  3);  ROUND1(D,A,B,C, 13,  7);
  74         ROUND1(C,D,A,B, 14, 11);  ROUND1(B,C,D,A, 15, 19);
  75
  76         ROUND2(A,B,C,D,  0,  3);  ROUND2(D,A,B,C,  4,  5);
  77         ROUND2(C,D,A,B,  8,  9);  ROUND2(B,C,D,A, 12, 13);
  78         ROUND2(A,B,C,D,  1,  3);  ROUND2(D,A,B,C,  5,  5);
  79         ROUND2(C,D,A,B,  9,  9);  ROUND2(B,C,D,A, 13, 13);
  80         ROUND2(A,B,C,D,  2,  3);  ROUND2(D,A,B,C,  6,  5);
  81         ROUND2(C,D,A,B, 10,  9);  ROUND2(B,C,D,A, 14, 13);
  82         ROUND2(A,B,C,D,  3,  3);  ROUND2(D,A,B,C,  7,  5);
  83         ROUND2(C,D,A,B, 11,  9);  ROUND2(B,C,D,A, 15, 13);
  84
  85         ROUND3(A,B,C,D,  0,  3);  ROUND3(D,A,B,C,  8,  9);
  86         ROUND3(C,D,A,B,  4, 11);  ROUND3(B,C,D,A, 12, 15);
  87         ROUND3(A,B,C,D,  2,  3);  ROUND3(D,A,B,C, 10,  9);
  88         ROUND3(C,D,A,B,  6, 11);  ROUND3(B,C,D,A, 14, 15);
  89         ROUND3(A,B,C,D,  1,  3);  ROUND3(D,A,B,C,  9,  9);
  90         ROUND3(C,D,A,B,  5, 11);  ROUND3(B,C,D,A, 13, 15);
  91         ROUND3(A,B,C,D,  3,  3);  ROUND3(D,A,B,C, 11,  9);
  92         ROUND3(C,D,A,B,  7, 11);  ROUND3(B,C,D,A, 15, 15);
  93
  94         A += AA; B += BB; C += CC; D += DD;
  95
  96         A &= 0xFFFFFFFF; B &= 0xFFFFFFFF;
  97         C &= 0xFFFFFFFF; D &= 0xFFFFFFFF;
  98
  99         for (j=0;j<16;j++)
 100                 X[j] = 0;
 101 }
 102
 103 static void copy64(uint32 *M, const unsigned char *in)
 104 {
 105         int i;
 106
 107         for (i=0;i<16;i++)
 108                 M[i] = (in[i*4+3]<<24) | (in[i*4+2]<<16) |
 109                         (in[i*4+1]<<8) | (in[i*4+0]<<0);
 110 }
 111
 112 static void copy4(unsigned char *out, uint32 x)
 113 {
 114         out[0] = x&0xFF;
 115         out[1] = (x>>8)&0xFF;
 116         out[2] = (x>>16)&0xFF;
 117         out[3] = (x>>24)&0xFF;
 118 }
 119
 120 /* produce a md4 message digest from data of length n bytes */
 121 void mdfour(unsigned char *out, const unsigned char *in, int n)
 122 {
 123         unsigned char buf[128];
 124         uint32 M[16];
 125         uint32 b = n * 8;
 126         int i;
 127
 128         A = 0x67452301;
 129         B = 0xefcdab89;
 130         C = 0x98badcfe;
 131         D = 0x10325476;
 132
 133         while (n > 64) {
 134                 copy64(M, in);
 135                 mdfour64(M);
 136                 in += 64;
 137                 n -= 64;
 138         }
 139
 140         for (i=0;i<128;i++)
 141                 buf[i] = 0;
 142         memcpy(buf, in, n);
 143         buf[n] = 0x80;
 144
 145         if (n <= 55) {
 146                 copy4(buf+56, b);
 147                 copy64(M, buf);
 148                 mdfour64(M);
 149         } else {
 150                 copy4(buf+120, b);
 151                 copy64(M, buf);
 152                 mdfour64(M);
 153                 copy64(M, buf+64);
 154                 mdfour64(M);
 155         }
 156
 157         for (i=0;i<128;i++)
 158                 buf[i] = 0;
 159         copy64(M, buf);
 160
 161         copy4(out, A);
 162         copy4(out+4, B);
 163         copy4(out+8, C);
 164         copy4(out+12, D);
 165
 166         A = B = C = D = 0;
 167 }
 168
 169