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 3 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, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21
  22 /* NOTE: This code makes no attempt to be fast!
  23
  24    It assumes that a int is at least 32 bits long
  25 */
  26
  27 #if 0
  28 static uint32 A, B, C, D;
  29 #else
  30 #define A (state[0])
  31 #define B (state[1])
  32 #define C (state[2])
  33 #define D (state[3])
  34 #endif
  35
  36 static uint32 F(uint32 X, uint32 Y, uint32 Z)
  37 {
  38         return (X&Y) | ((~X)&Z);
  39 }
  40
  41 static uint32 G(uint32 X, uint32 Y, uint32 Z)
  42 {
  43         return (X&Y) | (X&Z) | (Y&Z);
  44 }
  45
  46 static uint32 H(uint32 X, uint32 Y, uint32 Z)
  47 {
  48         return X^Y^Z;
  49 }
  50
  51 static uint32 lshift(uint32 x, int s)
  52 {
  53         x &= 0xFFFFFFFF;
  54         return ((x<<s)&0xFFFFFFFF) | (x>>(32-s));
  55 }
  56
  57 #define ROUND1(a,b,c,d,k,s) a = lshift(a + F(b,c,d) + X[k], s)
  58 #define ROUND2(a,b,c,d,k,s) a = lshift(a + G(b,c,d) + X[k] + (uint32)0x5A827999,s)
  59 #define ROUND3(a,b,c,d,k,s) a = lshift(a + H(b,c,d) + X[k] + (uint32)0x6ED9EBA1,s)
  60
  61 /* this applies md4 to 64 byte chunks */
  62 static void mdfour64(uint32_t *state, uint32 *M)
  63 {
  64         int j;
  65         uint32 AA, BB, CC, DD;
  66         uint32 X[16];
  67
  68         for (j=0;j<16;j++)
  69                 X[j] = M[j];
  70
  71         AA = A; BB = B; CC = C; DD = D;
  72
  73         ROUND1(A,B,C,D,  0,  3);  ROUND1(D,A,B,C,  1,  7);
  74         ROUND1(C,D,A,B,  2, 11);  ROUND1(B,C,D,A,  3, 19);
  75         ROUND1(A,B,C,D,  4,  3);  ROUND1(D,A,B,C,  5,  7);
  76         ROUND1(C,D,A,B,  6, 11);  ROUND1(B,C,D,A,  7, 19);
  77         ROUND1(A,B,C,D,  8,  3);  ROUND1(D,A,B,C,  9,  7);
  78         ROUND1(C,D,A,B, 10, 11);  ROUND1(B,C,D,A, 11, 19);
  79         ROUND1(A,B,C,D, 12,  3);  ROUND1(D,A,B,C, 13,  7);
  80         ROUND1(C,D,A,B, 14, 11);  ROUND1(B,C,D,A, 15, 19);
  81
  82         ROUND2(A,B,C,D,  0,  3);  ROUND2(D,A,B,C,  4,  5);
  83         ROUND2(C,D,A,B,  8,  9);  ROUND2(B,C,D,A, 12, 13);
  84         ROUND2(A,B,C,D,  1,  3);  ROUND2(D,A,B,C,  5,  5);
  85         ROUND2(C,D,A,B,  9,  9);  ROUND2(B,C,D,A, 13, 13);
  86         ROUND2(A,B,C,D,  2,  3);  ROUND2(D,A,B,C,  6,  5);
  87         ROUND2(C,D,A,B, 10,  9);  ROUND2(B,C,D,A, 14, 13);
  88         ROUND2(A,B,C,D,  3,  3);  ROUND2(D,A,B,C,  7,  5);
  89         ROUND2(C,D,A,B, 11,  9);  ROUND2(B,C,D,A, 15, 13);
  90
  91         ROUND3(A,B,C,D,  0,  3);  ROUND3(D,A,B,C,  8,  9);
  92         ROUND3(C,D,A,B,  4, 11);  ROUND3(B,C,D,A, 12, 15);
  93         ROUND3(A,B,C,D,  2,  3);  ROUND3(D,A,B,C, 10,  9);
  94         ROUND3(C,D,A,B,  6, 11);  ROUND3(B,C,D,A, 14, 15);
  95         ROUND3(A,B,C,D,  1,  3);  ROUND3(D,A,B,C,  9,  9);
  96         ROUND3(C,D,A,B,  5, 11);  ROUND3(B,C,D,A, 13, 15);
  97         ROUND3(A,B,C,D,  3,  3);  ROUND3(D,A,B,C, 11,  9);
  98         ROUND3(C,D,A,B,  7, 11);  ROUND3(B,C,D,A, 15, 15);
  99
 100         A += AA; B += BB; C += CC; D += DD;
 101
 102         A &= 0xFFFFFFFF; B &= 0xFFFFFFFF;
 103         C &= 0xFFFFFFFF; D &= 0xFFFFFFFF;
 104
 105         for (j=0;j<16;j++)
 106                 X[j] = 0;
 107 }
 108
 109 static void copy64(uint32 *M, const unsigned char *in)
 110 {
 111         int i;
 112
 113         for (i=0;i<16;i++)
 114                 M[i] = (in[i*4+3]<<24) | (in[i*4+2]<<16) |
 115                         (in[i*4+1]<<8) | (in[i*4+0]<<0);
 116 }
 117
 118 static void copy4(unsigned char *out, uint32 x)
 119 {
 120         out[0] = x&0xFF;
 121         out[1] = (x>>8)&0xFF;
 122         out[2] = (x>>16)&0xFF;
 123         out[3] = (x>>24)&0xFF;
 124 }
 125
 126 /* produce a md4 message digest from data of length n bytes */
 127 void mdfour(unsigned char *out, const unsigned char *in, int n)
 128 {
 129         unsigned char buf[128];
 130         uint32 M[16];
 131         uint32 state[4];
 132         uint32 b = n * 8;
 133         int i;
 134
 135         A = 0x67452301;
 136         B = 0xefcdab89;
 137         C = 0x98badcfe;
 138         D = 0x10325476;
 139
 140         while (n > 64) {
 141                 copy64(M, in);
 142                 mdfour64(state, M);
 143                 in += 64;
 144                 n -= 64;
 145         }
 146
 147         for (i=0;i<128;i++)
 148                 buf[i] = 0;
 149         memcpy(buf, in, n);
 150         buf[n] = 0x80;
 151
 152         if (n <= 55) {
 153                 copy4(buf+56, b);
 154                 copy64(M, buf);
 155                 mdfour64(state, M);
 156         } else {
 157                 copy4(buf+120, b);
 158                 copy64(M, buf);
 159                 mdfour64(state, M);
 160                 copy64(M, buf+64);
 161                 mdfour64(state, M);
 162         }
 163
 164         for (i=0;i<128;i++)
 165                 buf[i] = 0;
 166         copy64(M, buf);
 167
 168         copy4(out, A);
 169         copy4(out+4, B);
 170         copy4(out+8, C);
 171         copy4(out+12, D);
 172 }
 173
 174