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
28static __u32
29F(__u32 X, __u32 Y, __u32 Z)
30{
31	return (X & Y) | ((~X) & Z);
32}
33
34static __u32
35G(__u32 X, __u32 Y, __u32 Z)
36{
37	return (X & Y) | (X & Z) | (Y & Z);
38}
39
40static __u32
41H(__u32 X, __u32 Y, __u32 Z)
42{
43	return X ^ Y ^ Z;
44}
45
46static __u32
47lshift(__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 */
58static void
59mdfour64(__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
139static void
140copy64(__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
149static void
150copy4(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 */
159void
160mdfour(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}
206