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
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
23/* NOTE: This code makes no attempt to be fast!
24
25   It assumes that a int is at least 32 bits long
26*/
27
28typedef unsigned int uint32;
29
30static uint32 A, B, C, D;
31
32static uint32 F(uint32 X, uint32 Y, uint32 Z)
33{
34	return (X&Y) | ((~X)&Z);
35}
36
37static uint32 G(uint32 X, uint32 Y, uint32 Z)
38{
39	return (X&Y) | (X&Z) | (Y&Z);
40}
41
42static uint32 H(uint32 X, uint32 Y, uint32 Z)
43{
44	return X^Y^Z;
45}
46
47static uint32 lshift(uint32 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] + (uint32)0x5A827999,s)
55#define ROUND3(a,b,c,d,k,s) a = lshift(a + H(b,c,d) + X[k] + (uint32)0x6ED9EBA1,s)
56
57/* this applies md4 to 64 byte chunks */
58static void mdfour64(uint32 *M)
59{
60	int j;
61	uint32 AA, BB, CC, DD;
62	uint32 X[16];
63
64	for (j=0;j<16;j++)
65		X[j] = M[j];
66
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	A &= 0xFFFFFFFF; B &= 0xFFFFFFFF;
99	C &= 0xFFFFFFFF; D &= 0xFFFFFFFF;
100
101	for (j=0;j<16;j++)
102		X[j] = 0;
103}
104
105static void copy64(uint32 *M, unsigned char *in)
106{
107	int i;
108
109	for (i=0;i<16;i++)
110		M[i] = (in[i*4+3]<<24) | (in[i*4+2]<<16) |
111			(in[i*4+1]<<8) | (in[i*4+0]<<0);
112}
113
114static void copy4(unsigned char *out,uint32 x)
115{
116	out[0] = x&0xFF;
117	out[1] = (x>>8)&0xFF;
118	out[2] = (x>>16)&0xFF;
119	out[3] = (x>>24)&0xFF;
120}
121
122/* produce a md4 message digest from data of length n bytes */
123void mdfour(unsigned char *out, unsigned char *in, int n)
124{
125	unsigned char buf[128];
126	uint32 M[16];
127	uint32 b = n * 8;
128	int i;
129
130	A = 0x67452301;
131	B = 0xefcdab89;
132	C = 0x98badcfe;
133	D = 0x10325476;
134
135	while (n > 64) {
136		copy64(M, in);
137		mdfour64(M);
138		in += 64;
139		n -= 64;
140	}
141
142	for (i=0;i<128;i++)
143		buf[i] = 0;
144	memcpy(buf, in, n);
145	buf[n] = 0x80;
146
147	if (n <= 55) {
148		copy4(buf+56, b);
149		copy64(M, buf);
150		mdfour64(M);
151	} else {
152		copy4(buf+120, b);
153		copy64(M, buf);
154		mdfour64(M);
155		copy64(M, buf+64);
156		mdfour64(M);
157	}
158
159	for (i=0;i<128;i++)
160		buf[i] = 0;
161	copy64(M, buf);
162
163	copy4(out, A);
164	copy4(out+4, B);
165	copy4(out+8, C);
166	copy4(out+12, D);
167
168	A = B = C = D = 0;
169}
170
171
172