fs/cifs/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    Modified by Steve French (sfrench@us.ibm.com) 2002-2003
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22 #include <linux/module.h>
  23 #include <linux/fs.h>
  24 #include "cifsencrypt.h"
  25
  26 /* NOTE: This code makes no attempt to be fast! */
  27
  28 static __u32
  29 F(__u32 X, __u32 Y, __u32 Z)
  30 {
  31         return (X & Y) | ((~X) & Z);
  32 }
  33
  34 static __u32
  35 G(__u32 X, __u32 Y, __u32 Z)
  36 {
  37         return (X & Y) | (X & Z) | (Y & Z);
  38 }
  39
  40 static __u32
  41 H(__u32 X, __u32 Y, __u32 Z)
  42 {
  43         return X ^ Y ^ Z;
  44 }
  45
  46 static __u32
  47 lshift(__u32 x, int s)
  48 {
  49         x &= 0xFFFFFFFF;
  50         return ((x << s) & 0xFFFFFFFF) | (x >> (32 - s));
  51 }
  52
  53 #define ROUND1(a,b,c,d,k,s) (*a) = lshift((*a) + F(*b,*c,*d) + X[k], s)
  54 #define ROUND2(a,b,c,d,k,s) (*a) = lshift((*a) + G(*b,*c,*d) + X[k] + (__u32)0x5A827999,s)
  55 #define ROUND3(a,b,c,d,k,s) (*a) = lshift((*a) + H(*b,*c,*d) + X[k] + (__u32)0x6ED9EBA1,s)
  56
  57 /* this applies md4 to 64 byte chunks */
  58 static void
  59 mdfour64(__u32 *M, __u32 *A, __u32 *B, __u32 *C, __u32 *D)
  60 {
  61         int j;
  62         __u32 AA, BB, CC, DD;
  63         __u32 X[16];
  64
  65
  66         for (j = 0; j < 16; j++)
  67                 X[j] = M[j];
  68
  69         AA = *A;
  70         BB = *B;
  71         CC = *C;
  72         DD = *D;
  73
  74         ROUND1(A, B, C, D, 0, 3);
  75         ROUND1(D, A, B, C, 1, 7);
  76         ROUND1(C, D, A, B, 2, 11);
  77         ROUND1(B, C, D, A, 3, 19);
  78         ROUND1(A, B, C, D, 4, 3);
  79         ROUND1(D, A, B, C, 5, 7);
  80         ROUND1(C, D, A, B, 6, 11);
  81         ROUND1(B, C, D, A, 7, 19);
  82         ROUND1(A, B, C, D, 8, 3);
  83         ROUND1(D, A, B, C, 9, 7);
  84         ROUND1(C, D, A, B, 10, 11);
  85         ROUND1(B, C, D, A, 11, 19);
  86         ROUND1(A, B, C, D, 12, 3);
  87         ROUND1(D, A, B, C, 13, 7);
  88         ROUND1(C, D, A, B, 14, 11);
  89         ROUND1(B, C, D, A, 15, 19);
  90
  91         ROUND2(A, B, C, D, 0, 3);
  92         ROUND2(D, A, B, C, 4, 5);
  93         ROUND2(C, D, A, B, 8, 9);
  94         ROUND2(B, C, D, A, 12, 13);
  95         ROUND2(A, B, C, D, 1, 3);
  96         ROUND2(D, A, B, C, 5, 5);
  97         ROUND2(C, D, A, B, 9, 9);
  98         ROUND2(B, C, D, A, 13, 13);
  99         ROUND2(A, B, C, D, 2, 3);
 100         ROUND2(D, A, B, C, 6, 5);
 101         ROUND2(C, D, A, B, 10, 9);
 102         ROUND2(B, C, D, A, 14, 13);
 103         ROUND2(A, B, C, D, 3, 3);
 104         ROUND2(D, A, B, C, 7, 5);
 105         ROUND2(C, D, A, B, 11, 9);
 106         ROUND2(B, C, D, A, 15, 13);
 107
 108         ROUND3(A, B, C, D, 0, 3);
 109         ROUND3(D, A, B, C, 8, 9);
 110         ROUND3(C, D, A, B, 4, 11);
 111         ROUND3(B, C, D, A, 12, 15);
 112         ROUND3(A, B, C, D, 2, 3);
 113         ROUND3(D, A, B, C, 10, 9);
 114         ROUND3(C, D, A, B, 6, 11);
 115         ROUND3(B, C, D, A, 14, 15);
 116         ROUND3(A, B, C, D, 1, 3);
 117         ROUND3(D, A, B, C, 9, 9);
 118         ROUND3(C, D, A, B, 5, 11);
 119         ROUND3(B, C, D, A, 13, 15);
 120         ROUND3(A, B, C, D, 3, 3);
 121         ROUND3(D, A, B, C, 11, 9);
 122         ROUND3(C, D, A, B, 7, 11);
 123         ROUND3(B, C, D, A, 15, 15);
 124
 125         *A += AA;
 126         *B += BB;
 127         *C += CC;
 128         *D += DD;
 129
 130         *A &= 0xFFFFFFFF;
 131         *B &= 0xFFFFFFFF;
 132         *C &= 0xFFFFFFFF;
 133         *D &= 0xFFFFFFFF;
 134
 135         for (j = 0; j < 16; j++)
 136                 X[j] = 0;
 137 }
 138
 139 static void
 140 copy64(__u32 *M, unsigned char *in)
 141 {
 142         int i;
 143
 144         for (i = 0; i < 16; i++)
 145                 M[i] = (in[i * 4 + 3] << 24) | (in[i * 4 + 2] << 16) |
 146                     (in[i * 4 + 1] << 8) | (in[i * 4 + 0] << 0);
 147 }
 148
 149 static void
 150 copy4(unsigned char *out, __u32 x)
 151 {
 152         out[0] = x & 0xFF;
 153         out[1] = (x >> 8) & 0xFF;
 154         out[2] = (x >> 16) & 0xFF;
 155         out[3] = (x >> 24) & 0xFF;
 156 }
 157
 158 /* produce a md4 message digest from data of length n bytes */
 159 void
 160 mdfour(unsigned char *out, unsigned char *in, int n)
 161 {
 162         unsigned char buf[128];
 163         __u32 M[16];
 164         __u32 b = n * 8;
 165         int i;
 166         __u32 A = 0x67452301;
 167         __u32 B = 0xefcdab89;
 168         __u32 C = 0x98badcfe;
 169         __u32 D = 0x10325476;
 170
 171         while (n > 64) {
 172                 copy64(M, in);
 173                 mdfour64(M, &A, &B, &C, &D);
 174                 in += 64;
 175                 n -= 64;
 176         }
 177
 178         for (i = 0; i < 128; i++)
 179                 buf[i] = 0;
 180         memcpy(buf, in, n);
 181         buf[n] = 0x80;
 182
 183         if (n <= 55) {
 184                 copy4(buf + 56, b);
 185                 copy64(M, buf);
 186                 mdfour64(M, &A, &B, &C, &D);
 187         } else {
 188                 copy4(buf + 120, b);
 189                 copy64(M, buf);
 190                 mdfour64(M, &A, &B, &C, &D);
 191                 copy64(M, buf + 64);
 192                 mdfour64(M, &A, &B, &C, &D);
 193         }
 194
 195         for (i = 0; i < 128; i++)
 196                 buf[i] = 0;
 197         copy64(M, buf);
 198
 199         copy4(out, A);
 200         copy4(out + 4, B);
 201         copy4(out + 8, C);
 202         copy4(out + 12, D);
 203
 204         A = B = C = D = 0;
 205 }