summaryrefslogtreecommitdiffstats
path: root/fs/cifs/smbencrypt.c
blob: c12bffefa3c9b59b2290ecdb243ae308b08e7224 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
/*
   Unix SMB/Netbios implementation.
   Version 1.9.
   SMB parameters and setup
   Copyright (C) Andrew Tridgell 1992-2000
   Copyright (C) Luke Kenneth Casson Leighton 1996-2000
   Modified by Jeremy Allison 1995.
   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2002-2003
   Modified by Steve French (sfrench@us.ibm.com) 2002-2003

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include <linux/crypto.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/random.h>
#include "cifs_fs_sb.h"
#include "cifs_unicode.h"
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifs_debug.h"
#include "cifsproto.h"

#ifndef false
#define false 0
#endif
#ifndef true
#define true 1
#endif

/* following came from the other byteorder.h to avoid include conflicts */
#define CVAL(buf,pos) (((unsigned char *)(buf))[pos])
#define SSVALX(buf,pos,val) (CVAL(buf,pos)=(val)&0xFF,CVAL(buf,pos+1)=(val)>>8)
#define SSVAL(buf,pos,val) SSVALX((buf),(pos),((__u16)(val)))

static void
str_to_key(unsigned char *str, unsigned char *key)
{
	int i;

	key[0] = str[0] >> 1;
	key[1] = ((str[0] & 0x01) << 6) | (str[1] >> 2);
	key[2] = ((str[1] & 0x03) << 5) | (str[2] >> 3);
	key[3] = ((str[2] & 0x07) << 4) | (str[3] >> 4);
	key[4] = ((str[3] & 0x0F) << 3) | (str[4] >> 5);
	key[5] = ((str[4] & 0x1F) << 2) | (str[5] >> 6);
	key[6] = ((str[5] & 0x3F) << 1) | (str[6] >> 7);
	key[7] = str[6] & 0x7F;
	for (i = 0; i < 8; i++)
		key[i] = (key[i] << 1);
}

static int
smbhash(unsigned char *out, const unsigned char *in, unsigned char *key)
{
	unsigned char key2[8];
	struct crypto_cipher *tfm_des;

	str_to_key(key, key2);

	tfm_des = crypto_alloc_cipher("des", 0, 0);
	if (IS_ERR(tfm_des)) {
		cifs_dbg(VFS, "could not allocate des crypto API\n");
		return PTR_ERR(tfm_des);
	}

	crypto_cipher_setkey(tfm_des, key2, 8);
	crypto_cipher_encrypt_one(tfm_des, out, in);
	crypto_free_cipher(tfm_des);

	return 0;
}

static int
E_P16(unsigned char *p14, unsigned char *p16)
{
	int rc;
	unsigned char sp8[8] =
	    { 0x4b, 0x47, 0x53, 0x21, 0x40, 0x23, 0x24, 0x25 };

	rc = smbhash(p16, sp8, p14);
	if (rc)
		return rc;
	rc = smbhash(p16 + 8, sp8, p14 + 7);
	return rc;
}

static int
E_P24(unsigned char *p21, const unsigned char *c8, unsigned char *p24)
{
	int rc;

	rc = smbhash(p24, c8, p21);
	if (rc)
		return rc;
	rc = smbhash(p24 + 8, c8, p21 + 7);
	if (rc)
		return rc;
	rc = smbhash(p24 + 16, c8, p21 + 14);
	return rc;
}

/* produce a md4 message digest from data of length n bytes */
int
mdfour(unsigned char *md4_hash, unsigned char *link_str, int link_len)
{
	int rc;
	unsigned int size;
	struct crypto_shash *md4;
	struct sdesc *sdescmd4;

	md4 = crypto_alloc_shash("md4", 0, 0);
	if (IS_ERR(md4)) {
		rc = PTR_ERR(md4);
		cifs_dbg(VFS, "%s: Crypto md4 allocation error %d\n",
			 __func__, rc);
		return rc;
	}
	size = sizeof(struct shash_desc) + crypto_shash_descsize(md4);
	sdescmd4 = kmalloc(size, GFP_KERNEL);
	if (!sdescmd4) {
		rc = -ENOMEM;
		goto mdfour_err;
	}
	sdescmd4->shash.tfm = md4;
	sdescmd4->shash.flags = 0x0;

	rc = crypto_shash_init(&sdescmd4->shash);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not init md4 shash\n", __func__);
		goto mdfour_err;
	}
	rc = crypto_shash_update(&sdescmd4->shash, link_str, link_len);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
		goto mdfour_err;
	}
	rc = crypto_shash_final(&sdescmd4->shash, md4_hash);
	if (rc)
		cifs_dbg(VFS, "%s: Could not generate md4 hash\n", __func__);

mdfour_err:
	crypto_free_shash(md4);
	kfree(sdescmd4);

	return rc;
}

/*
   This implements the X/Open SMB password encryption
   It takes a password, a 8 byte "crypt key" and puts 24 bytes of
   encrypted password into p24 */
/* Note that password must be uppercased and null terminated */
int
SMBencrypt(unsigned char *passwd, const unsigned char *c8, unsigned char *p24)
{
	int rc;
	unsigned char p14[14], p16[16], p21[21];

	memset(p14, '\0', 14);
	memset(p16, '\0', 16);
	memset(p21, '\0', 21);

	memcpy(p14, passwd, 14);
	rc = E_P16(p14, p16);
	if (rc)
		return rc;

	memcpy(p21, p16, 16);
	rc = E_P24(p21, c8, p24);

	return rc;
}

/*
 * Creates the MD4 Hash of the users password in NT UNICODE.
 */

int
E_md4hash(const unsigned char *passwd, unsigned char *p16,
	const struct nls_table *codepage)
{
	int rc;
	int len;
	__le16 wpwd[129];

	/* Password cannot be longer than 128 characters */
	if (passwd) /* Password must be converted to NT unicode */
		len = cifs_strtoUTF16(wpwd, passwd, 128, codepage);
	else {
		len = 0;
		*wpwd = 0; /* Ensure string is null terminated */
	}

	rc = mdfour(p16, (unsigned char *) wpwd, len * sizeof(__le16));
	memzero_explicit(wpwd, sizeof(wpwd));

	return rc;
}

/* Does the NT MD4 hash then des encryption. */
int
SMBNTencrypt(unsigned char *passwd, unsigned char *c8, unsigned char *p24,
		const struct nls_table *codepage)
{
	int rc;
	unsigned char p16[16], p21[21];

	memset(p16, '\0', 16);
	memset(p21, '\0', 21);

	rc = E_md4hash(passwd, p16, codepage);
	if (rc) {
		cifs_dbg(FYI, "%s Can't generate NT hash, error: %d\n",
			 __func__, rc);
		return rc;
	}
	memcpy(p21, p16, 16);
	rc = E_P24(p21, c8, p24);
	return rc;
}