• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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/crypto.h>
27 #include <linux/module.h>
28 #include <linux/slab.h>
29 #include <linux/fs.h>
30 #include <linux/string.h>
31 #include <linux/kernel.h>
32 #include <linux/random.h>
33 #include "cifs_fs_sb.h"
34 #include "cifs_unicode.h"
35 #include "cifspdu.h"
36 #include "cifsglob.h"
37 #include "cifs_debug.h"
38 #include "cifsproto.h"
39 
40 #ifndef false
41 #define false 0
42 #endif
43 #ifndef true
44 #define true 1
45 #endif
46 
47 /* following came from the other byteorder.h to avoid include conflicts */
48 #define CVAL(buf,pos) (((unsigned char *)(buf))[pos])
49 #define SSVALX(buf,pos,val) (CVAL(buf,pos)=(val)&0xFF,CVAL(buf,pos+1)=(val)>>8)
50 #define SSVAL(buf,pos,val) SSVALX((buf),(pos),((__u16)(val)))
51 
52 static void
str_to_key(unsigned char * str,unsigned char * key)53 str_to_key(unsigned char *str, unsigned char *key)
54 {
55 	int i;
56 
57 	key[0] = str[0] >> 1;
58 	key[1] = ((str[0] & 0x01) << 6) | (str[1] >> 2);
59 	key[2] = ((str[1] & 0x03) << 5) | (str[2] >> 3);
60 	key[3] = ((str[2] & 0x07) << 4) | (str[3] >> 4);
61 	key[4] = ((str[3] & 0x0F) << 3) | (str[4] >> 5);
62 	key[5] = ((str[4] & 0x1F) << 2) | (str[5] >> 6);
63 	key[6] = ((str[5] & 0x3F) << 1) | (str[6] >> 7);
64 	key[7] = str[6] & 0x7F;
65 	for (i = 0; i < 8; i++)
66 		key[i] = (key[i] << 1);
67 }
68 
69 static int
smbhash(unsigned char * out,const unsigned char * in,unsigned char * key)70 smbhash(unsigned char *out, const unsigned char *in, unsigned char *key)
71 {
72 	unsigned char key2[8];
73 	struct crypto_cipher *tfm_des;
74 
75 	str_to_key(key, key2);
76 
77 	tfm_des = crypto_alloc_cipher("des", 0, 0);
78 	if (IS_ERR(tfm_des)) {
79 		cifs_dbg(VFS, "could not allocate des crypto API\n");
80 		return PTR_ERR(tfm_des);
81 	}
82 
83 	crypto_cipher_setkey(tfm_des, key2, 8);
84 	crypto_cipher_encrypt_one(tfm_des, out, in);
85 	crypto_free_cipher(tfm_des);
86 
87 	return 0;
88 }
89 
90 static int
E_P16(unsigned char * p14,unsigned char * p16)91 E_P16(unsigned char *p14, unsigned char *p16)
92 {
93 	int rc;
94 	unsigned char sp8[8] =
95 	    { 0x4b, 0x47, 0x53, 0x21, 0x40, 0x23, 0x24, 0x25 };
96 
97 	rc = smbhash(p16, sp8, p14);
98 	if (rc)
99 		return rc;
100 	rc = smbhash(p16 + 8, sp8, p14 + 7);
101 	return rc;
102 }
103 
104 static int
E_P24(unsigned char * p21,const unsigned char * c8,unsigned char * p24)105 E_P24(unsigned char *p21, const unsigned char *c8, unsigned char *p24)
106 {
107 	int rc;
108 
109 	rc = smbhash(p24, c8, p21);
110 	if (rc)
111 		return rc;
112 	rc = smbhash(p24 + 8, c8, p21 + 7);
113 	if (rc)
114 		return rc;
115 	rc = smbhash(p24 + 16, c8, p21 + 14);
116 	return rc;
117 }
118 
119 /* produce a md4 message digest from data of length n bytes */
120 int
mdfour(unsigned char * md4_hash,unsigned char * link_str,int link_len)121 mdfour(unsigned char *md4_hash, unsigned char *link_str, int link_len)
122 {
123 	int rc;
124 	unsigned int size;
125 	struct crypto_shash *md4;
126 	struct sdesc *sdescmd4;
127 
128 	md4 = crypto_alloc_shash("md4", 0, 0);
129 	if (IS_ERR(md4)) {
130 		rc = PTR_ERR(md4);
131 		cifs_dbg(VFS, "%s: Crypto md4 allocation error %d\n",
132 			 __func__, rc);
133 		return rc;
134 	}
135 	size = sizeof(struct shash_desc) + crypto_shash_descsize(md4);
136 	sdescmd4 = kmalloc(size, GFP_KERNEL);
137 	if (!sdescmd4) {
138 		rc = -ENOMEM;
139 		goto mdfour_err;
140 	}
141 	sdescmd4->shash.tfm = md4;
142 	sdescmd4->shash.flags = 0x0;
143 
144 	rc = crypto_shash_init(&sdescmd4->shash);
145 	if (rc) {
146 		cifs_dbg(VFS, "%s: Could not init md4 shash\n", __func__);
147 		goto mdfour_err;
148 	}
149 	rc = crypto_shash_update(&sdescmd4->shash, link_str, link_len);
150 	if (rc) {
151 		cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
152 		goto mdfour_err;
153 	}
154 	rc = crypto_shash_final(&sdescmd4->shash, md4_hash);
155 	if (rc)
156 		cifs_dbg(VFS, "%s: Could not generate md4 hash\n", __func__);
157 
158 mdfour_err:
159 	crypto_free_shash(md4);
160 	kfree(sdescmd4);
161 
162 	return rc;
163 }
164 
165 /*
166    This implements the X/Open SMB password encryption
167    It takes a password, a 8 byte "crypt key" and puts 24 bytes of
168    encrypted password into p24 */
169 /* Note that password must be uppercased and null terminated */
170 int
SMBencrypt(unsigned char * passwd,const unsigned char * c8,unsigned char * p24)171 SMBencrypt(unsigned char *passwd, const unsigned char *c8, unsigned char *p24)
172 {
173 	int rc;
174 	unsigned char p14[14], p16[16], p21[21];
175 
176 	memset(p14, '\0', 14);
177 	memset(p16, '\0', 16);
178 	memset(p21, '\0', 21);
179 
180 	memcpy(p14, passwd, 14);
181 	rc = E_P16(p14, p16);
182 	if (rc)
183 		return rc;
184 
185 	memcpy(p21, p16, 16);
186 	rc = E_P24(p21, c8, p24);
187 
188 	return rc;
189 }
190 
191 /*
192  * Creates the MD4 Hash of the users password in NT UNICODE.
193  */
194 
195 int
E_md4hash(const unsigned char * passwd,unsigned char * p16,const struct nls_table * codepage)196 E_md4hash(const unsigned char *passwd, unsigned char *p16,
197 	const struct nls_table *codepage)
198 {
199 	int rc;
200 	int len;
201 	__le16 wpwd[129];
202 
203 	/* Password cannot be longer than 128 characters */
204 	if (passwd) /* Password must be converted to NT unicode */
205 		len = cifs_strtoUTF16(wpwd, passwd, 128, codepage);
206 	else {
207 		len = 0;
208 		*wpwd = 0; /* Ensure string is null terminated */
209 	}
210 
211 	rc = mdfour(p16, (unsigned char *) wpwd, len * sizeof(__le16));
212 	memzero_explicit(wpwd, sizeof(wpwd));
213 
214 	return rc;
215 }
216 
217 /* Does the NT MD4 hash then des encryption. */
218 int
SMBNTencrypt(unsigned char * passwd,unsigned char * c8,unsigned char * p24,const struct nls_table * codepage)219 SMBNTencrypt(unsigned char *passwd, unsigned char *c8, unsigned char *p24,
220 		const struct nls_table *codepage)
221 {
222 	int rc;
223 	unsigned char p16[16], p21[21];
224 
225 	memset(p16, '\0', 16);
226 	memset(p21, '\0', 21);
227 
228 	rc = E_md4hash(passwd, p16, codepage);
229 	if (rc) {
230 		cifs_dbg(FYI, "%s Can't generate NT hash, error: %d\n",
231 			 __func__, rc);
232 		return rc;
233 	}
234 	memcpy(p21, p16, 16);
235 	rc = E_P24(p21, c8, p24);
236 	return rc;
237 }
238