1 /*
2 mdfour.c
3
4 An implementation of MD4 designed for use in the samba SMB
5 authentication protocol
6
7 Copyright (C) 1997-1998 Andrew Tridgell
8
9 This program is free software; you can redistribute it and/or
10 modify it under the terms of the GNU General Public License
11 as published by the Free Software Foundation; either version 2
12 of the License, or (at your option) any later version.
13
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
17
18 See the GNU General Public License for more details.
19
20 You should have received a copy of the GNU General Public License
21 along with this program; if not, write to:
22
23 Free Software Foundation, Inc.
24 59 Temple Place - Suite 330
25 Boston, MA 02111-1307, USA
26 */
27
28 #include "qcommon.h"
29
30 #if SIZEOF_INT > 4
31 #define LARGE_INT32
32 #endif
33
34
35 /* NOTE: This code makes no attempt to be fast!
36
37 It assumes that a int is at least 32 bits long
38 */
39
40 static struct mdfour *m;
41
42 #define F(X,Y,Z) (((X)&(Y)) | ((~(X))&(Z)))
43 #define G(X,Y,Z) (((X)&(Y)) | ((X)&(Z)) | ((Y)&(Z)))
44 #define H(X,Y,Z) ((X)^(Y)^(Z))
45 #ifdef LARGE_INT32
46 #define lshift(x,s) ((((x)<<(s))&0xFFFFFFFF) | (((x)>>(32-(s)))&0xFFFFFFFF))
47 #else
48 #define lshift(x,s) (((x)<<(s)) | ((x)>>(32-(s))))
49 #endif
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] + 0x5A827999,s)
53 #define ROUND3(a,b,c,d,k,s) a = lshift(a + H(b,c,d) + X[k] + 0x6ED9EBA1,s)
54
55 /* this applies md4 to 64 byte chunks */
mdfour64(uint32 * M)56 static void mdfour64(uint32 *M)
57 {
58 int j;
59 uint32 AA, BB, CC, DD;
60 uint32 X[16];
61 uint32 A,B,C,D;
62
63 for (j=0;j<16;j++)
64 X[j] = M[j];
65
66 A = m->A; B = m->B; C = m->C; D = m->D;
67 AA = A; BB = B; CC = C; DD = D;
68
69 ROUND1(A,B,C,D, 0, 3); ROUND1(D,A,B,C, 1, 7);
70 ROUND1(C,D,A,B, 2, 11); ROUND1(B,C,D,A, 3, 19);
71 ROUND1(A,B,C,D, 4, 3); ROUND1(D,A,B,C, 5, 7);
72 ROUND1(C,D,A,B, 6, 11); ROUND1(B,C,D,A, 7, 19);
73 ROUND1(A,B,C,D, 8, 3); ROUND1(D,A,B,C, 9, 7);
74 ROUND1(C,D,A,B, 10, 11); ROUND1(B,C,D,A, 11, 19);
75 ROUND1(A,B,C,D, 12, 3); ROUND1(D,A,B,C, 13, 7);
76 ROUND1(C,D,A,B, 14, 11); ROUND1(B,C,D,A, 15, 19);
77
78 ROUND2(A,B,C,D, 0, 3); ROUND2(D,A,B,C, 4, 5);
79 ROUND2(C,D,A,B, 8, 9); ROUND2(B,C,D,A, 12, 13);
80 ROUND2(A,B,C,D, 1, 3); ROUND2(D,A,B,C, 5, 5);
81 ROUND2(C,D,A,B, 9, 9); ROUND2(B,C,D,A, 13, 13);
82 ROUND2(A,B,C,D, 2, 3); ROUND2(D,A,B,C, 6, 5);
83 ROUND2(C,D,A,B, 10, 9); ROUND2(B,C,D,A, 14, 13);
84 ROUND2(A,B,C,D, 3, 3); ROUND2(D,A,B,C, 7, 5);
85 ROUND2(C,D,A,B, 11, 9); ROUND2(B,C,D,A, 15, 13);
86
87 ROUND3(A,B,C,D, 0, 3); ROUND3(D,A,B,C, 8, 9);
88 ROUND3(C,D,A,B, 4, 11); ROUND3(B,C,D,A, 12, 15);
89 ROUND3(A,B,C,D, 2, 3); ROUND3(D,A,B,C, 10, 9);
90 ROUND3(C,D,A,B, 6, 11); ROUND3(B,C,D,A, 14, 15);
91 ROUND3(A,B,C,D, 1, 3); ROUND3(D,A,B,C, 9, 9);
92 ROUND3(C,D,A,B, 5, 11); ROUND3(B,C,D,A, 13, 15);
93 ROUND3(A,B,C,D, 3, 3); ROUND3(D,A,B,C, 11, 9);
94 ROUND3(C,D,A,B, 7, 11); ROUND3(B,C,D,A, 15, 15);
95
96 A += AA; B += BB; C += CC; D += DD;
97
98 #ifdef LARGE_INT32
99 A &= 0xFFFFFFFF; B &= 0xFFFFFFFF;
100 C &= 0xFFFFFFFF; D &= 0xFFFFFFFF;
101 #endif
102
103 for (j=0;j<16;j++)
104 X[j] = 0;
105
106 m->A = A; m->B = B; m->C = C; m->D = D;
107 }
108
copy64(uint32 * M,uint8 * in)109 static void copy64(uint32 *M, uint8 *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
copy4(uint8 * out,uint32 x)118 static void copy4(uint8 *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
mdfour_begin(struct mdfour * md)126 void mdfour_begin(struct mdfour *md)
127 {
128 md->A = 0x67452301;
129 md->B = 0xefcdab89;
130 md->C = 0x98badcfe;
131 md->D = 0x10325476;
132 md->totalN = 0;
133 }
134
135
mdfour_tail(uint8 * in,int n)136 static void mdfour_tail(uint8 *in, int n)
137 {
138 uint8 buf[128];
139 uint32 M[16];
140 uint32 b;
141
142 m->totalN += n;
143
144 b = m->totalN * 8;
145
146 memset(buf, 0, 128);
147 if (n) memcpy(buf, in, n);
148 buf[n] = 0x80;
149
150 if (n <= 55) {
151 copy4(buf+56, b);
152 copy64(M, buf);
153 mdfour64(M);
154 } else {
155 copy4(buf+120, b);
156 copy64(M, buf);
157 mdfour64(M);
158 copy64(M, buf+64);
159 mdfour64(M);
160 }
161 }
162
mdfour_update(struct mdfour * md,uint8 * in,int n)163 void mdfour_update(struct mdfour *md, uint8 *in, int n)
164 {
165 uint32 M[16];
166
167 if (n == 0) mdfour_tail(in, n);
168
169 m = md;
170
171 while (n >= 64) {
172 copy64(M, in);
173 mdfour64(M);
174 in += 64;
175 n -= 64;
176 m->totalN += 64;
177 }
178
179 mdfour_tail(in, n);
180 }
181
182
mdfour_result(struct mdfour * md,uint8 * out)183 void mdfour_result(struct mdfour *md, uint8 *out)
184 {
185 m = md;
186
187 copy4(out, m->A);
188 copy4(out+4, m->B);
189 copy4(out+8, m->C);
190 copy4(out+12, m->D);
191 }
192
193 //===================================================================
194
Com_BlockChecksum(void * buffer,int length)195 uint32 Com_BlockChecksum( void *buffer, int length ) {
196 uint32 digest[4];
197 uint32 val;
198 struct mdfour md;
199
200 mdfour_begin( &md );
201 mdfour_update( &md, ( uint8 * )buffer, length );
202 mdfour_result( &md, ( uint8 * )digest );
203
204 val = digest[0] ^ digest[1] ^ digest[2] ^ digest[3];
205
206 return val;
207 }
208
209