source/lib/md4.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 1.9.
   4    a implementation of MD4 designed for use in the SMB authentication protocol
   5    Copyright (C) Andrew Tridgell 1997-1998.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 #include "includes.h"
  23
  24 /* NOTE: This code makes no attempt to be fast!
  25
  26    It assumes that a int is at least 32 bits long
  27 */
  28
  29 static uint32 A, B, C, D;
  30
  31 static uint32 F(uint32 X, uint32 Y, uint32 Z)
  32 {
  33         return (X&Y) | ((~X)&Z);
  34 }
  35
  36 static uint32 G(uint32 X, uint32 Y, uint32 Z)
  37 {
  38         return (X&Y) | (X&Z) | (Y&Z);
  39 }
  40
  41 static uint32 H(uint32 X, uint32 Y, uint32 Z)
  42 {
  43         return X^Y^Z;
  44 }
  45
  46 static uint32 lshift(uint32 x, int s)
  47 {
  48         x &= 0xFFFFFFFF;
  49         return ((x<<s)&0xFFFFFFFF) | (x>>(32-s));
  50 }
  51
  52 #define ROUND1(a,b,c,d,k,s) a = lshift(a + F(b,c,d) + X[k], s)
  53 #define ROUND2(a,b,c,d,k,s) a = lshift(a + G(b,c,d) + X[k] + (uint32)0x5A827999,s)
  54 #define ROUND3(a,b,c,d,k,s) a = lshift(a + H(b,c,d) + X[k] + (uint32)0x6ED9EBA1,s)
  55
  56 /* this applies md4 to 64 byte chunks */
  57 static void mdfour64(uint32 *M)
  58 {
  59         int j;
  60         uint32 AA, BB, CC, DD;
  61         uint32 X[16];
  62
  63         for (j=0;j<16;j++)
  64                 X[j] = M[j];
  65
  66         AA = A; BB = B; CC = C; DD = D;
  67
  68         ROUND1(A,B,C,D,  0,  3);  ROUND1(D,A,B,C,  1,  7);
  69         ROUND1(C,D,A,B,  2, 11);  ROUND1(B,C,D,A,  3, 19);
  70         ROUND1(A,B,C,D,  4,  3);  ROUND1(D,A,B,C,  5,  7);
  71         ROUND1(C,D,A,B,  6, 11);  ROUND1(B,C,D,A,  7, 19);
  72         ROUND1(A,B,C,D,  8,  3);  ROUND1(D,A,B,C,  9,  7);
  73         ROUND1(C,D,A,B, 10, 11);  ROUND1(B,C,D,A, 11, 19);
  74         ROUND1(A,B,C,D, 12,  3);  ROUND1(D,A,B,C, 13,  7);
  75         ROUND1(C,D,A,B, 14, 11);  ROUND1(B,C,D,A, 15, 19);
  76
  77         ROUND2(A,B,C,D,  0,  3);  ROUND2(D,A,B,C,  4,  5);
  78         ROUND2(C,D,A,B,  8,  9);  ROUND2(B,C,D,A, 12, 13);
  79         ROUND2(A,B,C,D,  1,  3);  ROUND2(D,A,B,C,  5,  5);
  80         ROUND2(C,D,A,B,  9,  9);  ROUND2(B,C,D,A, 13, 13);
  81         ROUND2(A,B,C,D,  2,  3);  ROUND2(D,A,B,C,  6,  5);
  82         ROUND2(C,D,A,B, 10,  9);  ROUND2(B,C,D,A, 14, 13);
  83         ROUND2(A,B,C,D,  3,  3);  ROUND2(D,A,B,C,  7,  5);
  84         ROUND2(C,D,A,B, 11,  9);  ROUND2(B,C,D,A, 15, 13);
  85
  86         ROUND3(A,B,C,D,  0,  3);  ROUND3(D,A,B,C,  8,  9);
  87         ROUND3(C,D,A,B,  4, 11);  ROUND3(B,C,D,A, 12, 15);
  88         ROUND3(A,B,C,D,  2,  3);  ROUND3(D,A,B,C, 10,  9);
  89         ROUND3(C,D,A,B,  6, 11);  ROUND3(B,C,D,A, 14, 15);
  90         ROUND3(A,B,C,D,  1,  3);  ROUND3(D,A,B,C,  9,  9);
  91         ROUND3(C,D,A,B,  5, 11);  ROUND3(B,C,D,A, 13, 15);
  92         ROUND3(A,B,C,D,  3,  3);  ROUND3(D,A,B,C, 11,  9);
  93         ROUND3(C,D,A,B,  7, 11);  ROUND3(B,C,D,A, 15, 15);
  94
  95         A += AA; B += BB; C += CC; D += DD;
  96
  97         A &= 0xFFFFFFFF; B &= 0xFFFFFFFF;
  98         C &= 0xFFFFFFFF; D &= 0xFFFFFFFF;
  99
 100         for (j=0;j<16;j++)
 101                 X[j] = 0;
 102 }
 103
 104 static void copy64(uint32 *M, unsigned char *in)
 105 {
 106         int i;
 107
 108         for (i=0;i<16;i++)
 109                 M[i] = (in[i*4+3]<<24) | (in[i*4+2]<<16) |
 110                         (in[i*4+1]<<8) | (in[i*4+0]<<0);
 111 }
 112
 113 static void copy4(unsigned char *out,uint32 x)
 114 {
 115         out[0] = x&0xFF;
 116         out[1] = (x>>8)&0xFF;
 117         out[2] = (x>>16)&0xFF;
 118         out[3] = (x>>24)&0xFF;
 119 }
 120
 121 /* produce a md4 message digest from data of length n bytes */
 122 void mdfour(unsigned char *out, unsigned char *in, int n)
 123 {
 124         unsigned char buf[128];
 125         uint32 M[16];
 126         uint32 b = n * 8;
 127         int i;
 128
 129         A = 0x67452301;
 130         B = 0xefcdab89;
 131         C = 0x98badcfe;
 132         D = 0x10325476;
 133
 134         while (n > 64) {
 135                 copy64(M, in);
 136                 mdfour64(M);
 137                 in += 64;
 138                 n -= 64;
 139         }
 140
 141         for (i=0;i<128;i++)
 142                 buf[i] = 0;
 143         memcpy(buf, in, n);
 144         buf[n] = 0x80;
 145
 146         if (n <= 55) {
 147                 copy4(buf+56, b);
 148                 copy64(M, buf);
 149                 mdfour64(M);
 150         } else {
 151                 copy4(buf+120, b);
 152                 copy64(M, buf);
 153                 mdfour64(M);
 154                 copy64(M, buf+64);
 155                 mdfour64(M);
 156         }
 157
 158         for (i=0;i<128;i++)
 159                 buf[i] = 0;
 160         copy64(M, buf);
 161
 162         copy4(out, A);
 163         copy4(out+4, B);
 164         copy4(out+8, C);
 165         copy4(out+12, D);
 166
 167         A = B = C = D = 0;
 168 }
 169
 170