1/*
2   Unix SMB/Netbios implementation.
3   Version 1.9.
4   SMB parameters and setup
5   Copyright (C) Andrew Tridgell 1992-2000
6   Copyright (C) Luke Kenneth Casson Leighton 1996-2000
7   Modified by Jeremy Allison 1995.
8   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2002-2003
9   Modified by Steve French (sfrench@us.ibm.com) 2002-2003
10
11   This program is free software; you can redistribute it and/or modify
12   it under the terms of the GNU General Public License as published by
13   the Free Software Foundation; either version 2 of the License, or
14   (at your option) any later version.
15
16   This program is distributed in the hope that it will be useful,
17   but WITHOUT ANY WARRANTY; without even the implied warranty of
18   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19   GNU General Public License for more details.
20
21   You should have received a copy of the GNU General Public License
22   along with this program; if not, write to the Free Software
23   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24*/
25
26#include <linux/module.h>
27#include <linux/slab.h>
28#include <linux/fs.h>
29#include <linux/string.h>
30#include <linux/kernel.h>
31#include <linux/random.h>
32#include "cifs_fs_sb.h"
33#include "cifs_unicode.h"
34#include "cifspdu.h"
35#include "cifsglob.h"
36#include "cifs_debug.h"
37#include "cifsproto.h"
38
39#ifndef false
40#define false 0
41#endif
42#ifndef true
43#define true 1
44#endif
45
46/* following came from the other byteorder.h to avoid include conflicts */
47#define CVAL(buf,pos) (((unsigned char *)(buf))[pos])
48#define SSVALX(buf,pos,val) (CVAL(buf,pos)=(val)&0xFF,CVAL(buf,pos+1)=(val)>>8)
49#define SSVAL(buf,pos,val) SSVALX((buf),(pos),((__u16)(val)))
50
51static void
52str_to_key(unsigned char *str, unsigned char *key)
53{
54	int i;
55
56	key[0] = str[0] >> 1;
57	key[1] = ((str[0] & 0x01) << 6) | (str[1] >> 2);
58	key[2] = ((str[1] & 0x03) << 5) | (str[2] >> 3);
59	key[3] = ((str[2] & 0x07) << 4) | (str[3] >> 4);
60	key[4] = ((str[3] & 0x0F) << 3) | (str[4] >> 5);
61	key[5] = ((str[4] & 0x1F) << 2) | (str[5] >> 6);
62	key[6] = ((str[5] & 0x3F) << 1) | (str[6] >> 7);
63	key[7] = str[6] & 0x7F;
64	for (i = 0; i < 8; i++)
65		key[i] = (key[i] << 1);
66}
67
68static int
69smbhash(unsigned char *out, const unsigned char *in, unsigned char *key)
70{
71	int rc;
72	unsigned char key2[8];
73	struct crypto_blkcipher *tfm_des;
74	struct scatterlist sgin, sgout;
75	struct blkcipher_desc desc;
76
77	str_to_key(key, key2);
78
79	tfm_des = crypto_alloc_blkcipher("ecb(des)", 0, CRYPTO_ALG_ASYNC);
80	if (IS_ERR(tfm_des)) {
81		rc = PTR_ERR(tfm_des);
82		cifs_dbg(VFS, "could not allocate des crypto API\n");
83		goto smbhash_err;
84	}
85
86	desc.tfm = tfm_des;
87
88	crypto_blkcipher_setkey(tfm_des, key2, 8);
89
90	sg_init_one(&sgin, in, 8);
91	sg_init_one(&sgout, out, 8);
92
93	rc = crypto_blkcipher_encrypt(&desc, &sgout, &sgin, 8);
94	if (rc)
95		cifs_dbg(VFS, "could not encrypt crypt key rc: %d\n", rc);
96
97	crypto_free_blkcipher(tfm_des);
98smbhash_err:
99	return rc;
100}
101
102static int
103E_P16(unsigned char *p14, unsigned char *p16)
104{
105	int rc;
106	unsigned char sp8[8] =
107	    { 0x4b, 0x47, 0x53, 0x21, 0x40, 0x23, 0x24, 0x25 };
108
109	rc = smbhash(p16, sp8, p14);
110	if (rc)
111		return rc;
112	rc = smbhash(p16 + 8, sp8, p14 + 7);
113	return rc;
114}
115
116static int
117E_P24(unsigned char *p21, const unsigned char *c8, unsigned char *p24)
118{
119	int rc;
120
121	rc = smbhash(p24, c8, p21);
122	if (rc)
123		return rc;
124	rc = smbhash(p24 + 8, c8, p21 + 7);
125	if (rc)
126		return rc;
127	rc = smbhash(p24 + 16, c8, p21 + 14);
128	return rc;
129}
130
131/* produce a md4 message digest from data of length n bytes */
132int
133mdfour(unsigned char *md4_hash, unsigned char *link_str, int link_len)
134{
135	int rc;
136	unsigned int size;
137	struct crypto_shash *md4;
138	struct sdesc *sdescmd4;
139
140	md4 = crypto_alloc_shash("md4", 0, 0);
141	if (IS_ERR(md4)) {
142		rc = PTR_ERR(md4);
143		cifs_dbg(VFS, "%s: Crypto md4 allocation error %d\n",
144			 __func__, rc);
145		return rc;
146	}
147	size = sizeof(struct shash_desc) + crypto_shash_descsize(md4);
148	sdescmd4 = kmalloc(size, GFP_KERNEL);
149	if (!sdescmd4) {
150		rc = -ENOMEM;
151		goto mdfour_err;
152	}
153	sdescmd4->shash.tfm = md4;
154	sdescmd4->shash.flags = 0x0;
155
156	rc = crypto_shash_init(&sdescmd4->shash);
157	if (rc) {
158		cifs_dbg(VFS, "%s: Could not init md4 shash\n", __func__);
159		goto mdfour_err;
160	}
161	rc = crypto_shash_update(&sdescmd4->shash, link_str, link_len);
162	if (rc) {
163		cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
164		goto mdfour_err;
165	}
166	rc = crypto_shash_final(&sdescmd4->shash, md4_hash);
167	if (rc)
168		cifs_dbg(VFS, "%s: Could not generate md4 hash\n", __func__);
169
170mdfour_err:
171	crypto_free_shash(md4);
172	kfree(sdescmd4);
173
174	return rc;
175}
176
177/*
178   This implements the X/Open SMB password encryption
179   It takes a password, a 8 byte "crypt key" and puts 24 bytes of
180   encrypted password into p24 */
181/* Note that password must be uppercased and null terminated */
182int
183SMBencrypt(unsigned char *passwd, const unsigned char *c8, unsigned char *p24)
184{
185	int rc;
186	unsigned char p14[14], p16[16], p21[21];
187
188	memset(p14, '\0', 14);
189	memset(p16, '\0', 16);
190	memset(p21, '\0', 21);
191
192	memcpy(p14, passwd, 14);
193	rc = E_P16(p14, p16);
194	if (rc)
195		return rc;
196
197	memcpy(p21, p16, 16);
198	rc = E_P24(p21, c8, p24);
199
200	return rc;
201}
202
203/*
204 * Creates the MD4 Hash of the users password in NT UNICODE.
205 */
206
207int
208E_md4hash(const unsigned char *passwd, unsigned char *p16,
209	const struct nls_table *codepage)
210{
211	int rc;
212	int len;
213	__le16 wpwd[129];
214
215	/* Password cannot be longer than 128 characters */
216	if (passwd) /* Password must be converted to NT unicode */
217		len = cifs_strtoUTF16(wpwd, passwd, 128, codepage);
218	else {
219		len = 0;
220		*wpwd = 0; /* Ensure string is null terminated */
221	}
222
223	rc = mdfour(p16, (unsigned char *) wpwd, len * sizeof(__le16));
224	memzero_explicit(wpwd, sizeof(wpwd));
225
226	return rc;
227}
228
229/* Does the NT MD4 hash then des encryption. */
230int
231SMBNTencrypt(unsigned char *passwd, unsigned char *c8, unsigned char *p24,
232		const struct nls_table *codepage)
233{
234	int rc;
235	unsigned char p16[16], p21[21];
236
237	memset(p16, '\0', 16);
238	memset(p21, '\0', 21);
239
240	rc = E_md4hash(passwd, p16, codepage);
241	if (rc) {
242		cifs_dbg(FYI, "%s Can't generate NT hash, error: %d\n",
243			 __func__, rc);
244		return rc;
245	}
246	memcpy(p21, p16, 16);
247	rc = E_P24(p21, c8, p24);
248	return rc;
249}
250