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1 | /* | |
2 | * fs/cifs/cifsencrypt.c | |
3 | * | |
4 | * Copyright (C) International Business Machines Corp., 2005,2006 | |
5 | * Author(s): Steve French (sfrench@us.ibm.com) | |
6 | * | |
7 | * This library is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU Lesser General Public License as published | |
9 | * by the Free Software Foundation; either version 2.1 of the License, or | |
10 | * (at your option) any later version. | |
11 | * | |
12 | * This library 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 | |
15 | * the GNU Lesser General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU Lesser General Public License | |
18 | * along with this library; if not, write to the Free Software | |
19 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
20 | */ | |
21 | ||
22 | #include <linux/fs.h> | |
23 | #include "cifspdu.h" | |
24 | #include "cifsglob.h" | |
25 | #include "cifs_debug.h" | |
26 | #include "md5.h" | |
27 | #include "cifs_unicode.h" | |
28 | #include "cifsproto.h" | |
29 | #include <linux/ctype.h> | |
30 | #include <linux/random.h> | |
31 | ||
32 | /* Calculate and return the CIFS signature based on the mac key and SMB PDU */ | |
33 | /* the 16 byte signature must be allocated by the caller */ | |
34 | /* Note we only use the 1st eight bytes */ | |
35 | /* Note that the smb header signature field on input contains the | |
36 | sequence number before this function is called */ | |
37 | ||
38 | extern void mdfour(unsigned char *out, unsigned char *in, int n); | |
39 | extern void E_md4hash(const unsigned char *passwd, unsigned char *p16); | |
40 | extern void SMBencrypt(unsigned char *passwd, unsigned char *c8, | |
41 | unsigned char *p24); | |
42 | ||
43 | static int cifs_calculate_signature(const struct smb_hdr *cifs_pdu, | |
44 | const struct mac_key *key, char *signature) | |
45 | { | |
46 | struct MD5Context context; | |
47 | ||
48 | if ((cifs_pdu == NULL) || (signature == NULL) || (key == NULL)) | |
49 | return -EINVAL; | |
50 | ||
51 | MD5Init(&context); | |
52 | MD5Update(&context, (char *)&key->data, key->len); | |
53 | MD5Update(&context, cifs_pdu->Protocol, cifs_pdu->smb_buf_length); | |
54 | ||
55 | MD5Final(signature, &context); | |
56 | return 0; | |
57 | } | |
58 | ||
59 | int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server, | |
60 | __u32 *pexpected_response_sequence_number) | |
61 | { | |
62 | int rc = 0; | |
63 | char smb_signature[20]; | |
64 | ||
65 | if ((cifs_pdu == NULL) || (server == NULL)) | |
66 | return -EINVAL; | |
67 | ||
68 | if ((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0) | |
69 | return rc; | |
70 | ||
71 | spin_lock(&GlobalMid_Lock); | |
72 | cifs_pdu->Signature.Sequence.SequenceNumber = | |
73 | cpu_to_le32(server->sequence_number); | |
74 | cifs_pdu->Signature.Sequence.Reserved = 0; | |
75 | ||
76 | *pexpected_response_sequence_number = server->sequence_number++; | |
77 | server->sequence_number++; | |
78 | spin_unlock(&GlobalMid_Lock); | |
79 | ||
80 | rc = cifs_calculate_signature(cifs_pdu, &server->mac_signing_key, | |
81 | smb_signature); | |
82 | if (rc) | |
83 | memset(cifs_pdu->Signature.SecuritySignature, 0, 8); | |
84 | else | |
85 | memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8); | |
86 | ||
87 | return rc; | |
88 | } | |
89 | ||
90 | static int cifs_calc_signature2(const struct kvec *iov, int n_vec, | |
91 | const struct mac_key *key, char *signature) | |
92 | { | |
93 | struct MD5Context context; | |
94 | int i; | |
95 | ||
96 | if ((iov == NULL) || (signature == NULL) || (key == NULL)) | |
97 | return -EINVAL; | |
98 | ||
99 | MD5Init(&context); | |
100 | MD5Update(&context, (char *)&key->data, key->len); | |
101 | for (i = 0; i < n_vec; i++) { | |
102 | if (iov[i].iov_base == NULL) { | |
103 | cERROR(1, ("null iovec entry")); | |
104 | return -EIO; | |
105 | } else if (iov[i].iov_len == 0) | |
106 | break; /* bail out if we are sent nothing to sign */ | |
107 | /* The first entry includes a length field (which does not get | |
108 | signed that occupies the first 4 bytes before the header */ | |
109 | if (i == 0) { | |
110 | if (iov[0].iov_len <= 8 ) /* cmd field at offset 9 */ | |
111 | break; /* nothing to sign or corrupt header */ | |
112 | MD5Update(&context, iov[0].iov_base+4, | |
113 | iov[0].iov_len-4); | |
114 | } else | |
115 | MD5Update(&context, iov[i].iov_base, iov[i].iov_len); | |
116 | } | |
117 | ||
118 | MD5Final(signature, &context); | |
119 | ||
120 | return 0; | |
121 | } | |
122 | ||
123 | ||
124 | int cifs_sign_smb2(struct kvec *iov, int n_vec, struct TCP_Server_Info *server, | |
125 | __u32 * pexpected_response_sequence_number) | |
126 | { | |
127 | int rc = 0; | |
128 | char smb_signature[20]; | |
129 | struct smb_hdr *cifs_pdu = iov[0].iov_base; | |
130 | ||
131 | if ((cifs_pdu == NULL) || (server == NULL)) | |
132 | return -EINVAL; | |
133 | ||
134 | if ((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0) | |
135 | return rc; | |
136 | ||
137 | spin_lock(&GlobalMid_Lock); | |
138 | cifs_pdu->Signature.Sequence.SequenceNumber = | |
139 | cpu_to_le32(server->sequence_number); | |
140 | cifs_pdu->Signature.Sequence.Reserved = 0; | |
141 | ||
142 | *pexpected_response_sequence_number = server->sequence_number++; | |
143 | server->sequence_number++; | |
144 | spin_unlock(&GlobalMid_Lock); | |
145 | ||
146 | rc = cifs_calc_signature2(iov, n_vec, &server->mac_signing_key, | |
147 | smb_signature); | |
148 | if (rc) | |
149 | memset(cifs_pdu->Signature.SecuritySignature, 0, 8); | |
150 | else | |
151 | memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8); | |
152 | ||
153 | return rc; | |
154 | } | |
155 | ||
156 | int cifs_verify_signature(struct smb_hdr *cifs_pdu, | |
157 | const struct mac_key *mac_key, | |
158 | __u32 expected_sequence_number) | |
159 | { | |
160 | unsigned int rc; | |
161 | char server_response_sig[8]; | |
162 | char what_we_think_sig_should_be[20]; | |
163 | ||
164 | if ((cifs_pdu == NULL) || (mac_key == NULL)) | |
165 | return -EINVAL; | |
166 | ||
167 | if (cifs_pdu->Command == SMB_COM_NEGOTIATE) | |
168 | return 0; | |
169 | ||
170 | if (cifs_pdu->Command == SMB_COM_LOCKING_ANDX) { | |
171 | struct smb_com_lock_req *pSMB = | |
172 | (struct smb_com_lock_req *)cifs_pdu; | |
173 | if (pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE) | |
174 | return 0; | |
175 | } | |
176 | ||
177 | /* BB what if signatures are supposed to be on for session but | |
178 | server does not send one? BB */ | |
179 | ||
180 | /* Do not need to verify session setups with signature "BSRSPYL " */ | |
181 | if (memcmp(cifs_pdu->Signature.SecuritySignature, "BSRSPYL ", 8) == 0) | |
182 | cFYI(1, ("dummy signature received for smb command 0x%x", | |
183 | cifs_pdu->Command)); | |
184 | ||
185 | /* save off the origiginal signature so we can modify the smb and check | |
186 | its signature against what the server sent */ | |
187 | memcpy(server_response_sig, cifs_pdu->Signature.SecuritySignature, 8); | |
188 | ||
189 | cifs_pdu->Signature.Sequence.SequenceNumber = | |
190 | cpu_to_le32(expected_sequence_number); | |
191 | cifs_pdu->Signature.Sequence.Reserved = 0; | |
192 | ||
193 | rc = cifs_calculate_signature(cifs_pdu, mac_key, | |
194 | what_we_think_sig_should_be); | |
195 | ||
196 | if (rc) | |
197 | return rc; | |
198 | ||
199 | /* cifs_dump_mem("what we think it should be: ", | |
200 | what_we_think_sig_should_be, 16); */ | |
201 | ||
202 | if (memcmp(server_response_sig, what_we_think_sig_should_be, 8)) | |
203 | return -EACCES; | |
204 | else | |
205 | return 0; | |
206 | ||
207 | } | |
208 | ||
209 | /* We fill in key by putting in 40 byte array which was allocated by caller */ | |
210 | int cifs_calculate_mac_key(struct mac_key *key, const char *rn, | |
211 | const char *password) | |
212 | { | |
213 | char temp_key[16]; | |
214 | if ((key == NULL) || (rn == NULL)) | |
215 | return -EINVAL; | |
216 | ||
217 | E_md4hash(password, temp_key); | |
218 | mdfour(key->data.ntlm, temp_key, 16); | |
219 | memcpy(key->data.ntlm+16, rn, CIFS_SESS_KEY_SIZE); | |
220 | key->len = 40; | |
221 | return 0; | |
222 | } | |
223 | ||
224 | int CalcNTLMv2_partial_mac_key(struct cifsSesInfo *ses, | |
225 | const struct nls_table *nls_info) | |
226 | { | |
227 | char temp_hash[16]; | |
228 | struct HMACMD5Context ctx; | |
229 | char *ucase_buf; | |
230 | __le16 *unicode_buf; | |
231 | unsigned int i, user_name_len, dom_name_len; | |
232 | ||
233 | if (ses == NULL) | |
234 | return -EINVAL; | |
235 | ||
236 | E_md4hash(ses->password, temp_hash); | |
237 | ||
238 | hmac_md5_init_limK_to_64(temp_hash, 16, &ctx); | |
239 | user_name_len = strlen(ses->userName); | |
240 | if (user_name_len > MAX_USERNAME_SIZE) | |
241 | return -EINVAL; | |
242 | if (ses->domainName == NULL) | |
243 | return -EINVAL; /* BB should we use CIFS_LINUX_DOM */ | |
244 | dom_name_len = strlen(ses->domainName); | |
245 | if (dom_name_len > MAX_USERNAME_SIZE) | |
246 | return -EINVAL; | |
247 | ||
248 | ucase_buf = kmalloc((MAX_USERNAME_SIZE+1), GFP_KERNEL); | |
249 | if (ucase_buf == NULL) | |
250 | return -ENOMEM; | |
251 | unicode_buf = kmalloc((MAX_USERNAME_SIZE+1)*4, GFP_KERNEL); | |
252 | if (unicode_buf == NULL) { | |
253 | kfree(ucase_buf); | |
254 | return -ENOMEM; | |
255 | } | |
256 | ||
257 | for (i = 0; i < user_name_len; i++) | |
258 | ucase_buf[i] = nls_info->charset2upper[(int)ses->userName[i]]; | |
259 | ucase_buf[i] = 0; | |
260 | user_name_len = cifs_strtoUCS(unicode_buf, ucase_buf, | |
261 | MAX_USERNAME_SIZE*2, nls_info); | |
262 | unicode_buf[user_name_len] = 0; | |
263 | user_name_len++; | |
264 | ||
265 | for (i = 0; i < dom_name_len; i++) | |
266 | ucase_buf[i] = nls_info->charset2upper[(int)ses->domainName[i]]; | |
267 | ucase_buf[i] = 0; | |
268 | dom_name_len = cifs_strtoUCS(unicode_buf+user_name_len, ucase_buf, | |
269 | MAX_USERNAME_SIZE*2, nls_info); | |
270 | ||
271 | unicode_buf[user_name_len + dom_name_len] = 0; | |
272 | hmac_md5_update((const unsigned char *) unicode_buf, | |
273 | (user_name_len+dom_name_len)*2, &ctx); | |
274 | ||
275 | hmac_md5_final(ses->server->ntlmv2_hash, &ctx); | |
276 | kfree(ucase_buf); | |
277 | kfree(unicode_buf); | |
278 | return 0; | |
279 | } | |
280 | ||
281 | #ifdef CONFIG_CIFS_WEAK_PW_HASH | |
282 | void calc_lanman_hash(struct cifsSesInfo *ses, char *lnm_session_key) | |
283 | { | |
284 | int i; | |
285 | char password_with_pad[CIFS_ENCPWD_SIZE]; | |
286 | ||
287 | if (ses->server == NULL) | |
288 | return; | |
289 | ||
290 | memset(password_with_pad, 0, CIFS_ENCPWD_SIZE); | |
291 | if (ses->password) | |
292 | strncpy(password_with_pad, ses->password, CIFS_ENCPWD_SIZE); | |
293 | ||
294 | if ((ses->server->secMode & SECMODE_PW_ENCRYPT) == 0) | |
295 | if (extended_security & CIFSSEC_MAY_PLNTXT) { | |
296 | memcpy(lnm_session_key, password_with_pad, | |
297 | CIFS_ENCPWD_SIZE); | |
298 | return; | |
299 | } | |
300 | ||
301 | /* calculate old style session key */ | |
302 | /* calling toupper is less broken than repeatedly | |
303 | calling nls_toupper would be since that will never | |
304 | work for UTF8, but neither handles multibyte code pages | |
305 | but the only alternative would be converting to UCS-16 (Unicode) | |
306 | (using a routine something like UniStrupr) then | |
307 | uppercasing and then converting back from Unicode - which | |
308 | would only worth doing it if we knew it were utf8. Basically | |
309 | utf8 and other multibyte codepages each need their own strupper | |
310 | function since a byte at a time will ont work. */ | |
311 | ||
312 | for (i = 0; i < CIFS_ENCPWD_SIZE; i++) { | |
313 | password_with_pad[i] = toupper(password_with_pad[i]); | |
314 | } | |
315 | ||
316 | SMBencrypt(password_with_pad, ses->server->cryptKey, lnm_session_key); | |
317 | /* clear password before we return/free memory */ | |
318 | memset(password_with_pad, 0, CIFS_ENCPWD_SIZE); | |
319 | } | |
320 | #endif /* CIFS_WEAK_PW_HASH */ | |
321 | ||
322 | static int calc_ntlmv2_hash(struct cifsSesInfo *ses, | |
323 | const struct nls_table *nls_cp) | |
324 | { | |
325 | int rc = 0; | |
326 | int len; | |
327 | char nt_hash[16]; | |
328 | struct HMACMD5Context *pctxt; | |
329 | wchar_t *user; | |
330 | wchar_t *domain; | |
331 | ||
332 | pctxt = kmalloc(sizeof(struct HMACMD5Context), GFP_KERNEL); | |
333 | ||
334 | if (pctxt == NULL) | |
335 | return -ENOMEM; | |
336 | ||
337 | /* calculate md4 hash of password */ | |
338 | E_md4hash(ses->password, nt_hash); | |
339 | ||
340 | /* convert Domainname to unicode and uppercase */ | |
341 | hmac_md5_init_limK_to_64(nt_hash, 16, pctxt); | |
342 | ||
343 | /* convert ses->userName to unicode and uppercase */ | |
344 | len = strlen(ses->userName); | |
345 | user = kmalloc(2 + (len * 2), GFP_KERNEL); | |
346 | if (user == NULL) | |
347 | goto calc_exit_2; | |
348 | len = cifs_strtoUCS(user, ses->userName, len, nls_cp); | |
349 | UniStrupr(user); | |
350 | hmac_md5_update((char *)user, 2*len, pctxt); | |
351 | ||
352 | /* convert ses->domainName to unicode and uppercase */ | |
353 | if (ses->domainName) { | |
354 | len = strlen(ses->domainName); | |
355 | ||
356 | domain = kmalloc(2 + (len * 2), GFP_KERNEL); | |
357 | if (domain == NULL) | |
358 | goto calc_exit_1; | |
359 | len = cifs_strtoUCS(domain, ses->domainName, len, nls_cp); | |
360 | /* the following line was removed since it didn't work well | |
361 | with lower cased domain name that passed as an option. | |
362 | Maybe converting the domain name earlier makes sense */ | |
363 | /* UniStrupr(domain); */ | |
364 | ||
365 | hmac_md5_update((char *)domain, 2*len, pctxt); | |
366 | ||
367 | kfree(domain); | |
368 | } | |
369 | calc_exit_1: | |
370 | kfree(user); | |
371 | calc_exit_2: | |
372 | /* BB FIXME what about bytes 24 through 40 of the signing key? | |
373 | compare with the NTLM example */ | |
374 | hmac_md5_final(ses->server->ntlmv2_hash, pctxt); | |
375 | ||
376 | return rc; | |
377 | } | |
378 | ||
379 | void setup_ntlmv2_rsp(struct cifsSesInfo *ses, char *resp_buf, | |
380 | const struct nls_table *nls_cp) | |
381 | { | |
382 | int rc; | |
383 | struct ntlmv2_resp *buf = (struct ntlmv2_resp *)resp_buf; | |
384 | struct HMACMD5Context context; | |
385 | ||
386 | buf->blob_signature = cpu_to_le32(0x00000101); | |
387 | buf->reserved = 0; | |
388 | buf->time = cpu_to_le64(cifs_UnixTimeToNT(CURRENT_TIME)); | |
389 | get_random_bytes(&buf->client_chal, sizeof(buf->client_chal)); | |
390 | buf->reserved2 = 0; | |
391 | buf->names[0].type = cpu_to_le16(NTLMSSP_DOMAIN_TYPE); | |
392 | buf->names[0].length = 0; | |
393 | buf->names[1].type = 0; | |
394 | buf->names[1].length = 0; | |
395 | ||
396 | /* calculate buf->ntlmv2_hash */ | |
397 | rc = calc_ntlmv2_hash(ses, nls_cp); | |
398 | if (rc) | |
399 | cERROR(1, ("could not get v2 hash rc %d", rc)); | |
400 | CalcNTLMv2_response(ses, resp_buf); | |
401 | ||
402 | /* now calculate the MAC key for NTLMv2 */ | |
403 | hmac_md5_init_limK_to_64(ses->server->ntlmv2_hash, 16, &context); | |
404 | hmac_md5_update(resp_buf, 16, &context); | |
405 | hmac_md5_final(ses->server->mac_signing_key.data.ntlmv2.key, &context); | |
406 | ||
407 | memcpy(&ses->server->mac_signing_key.data.ntlmv2.resp, resp_buf, | |
408 | sizeof(struct ntlmv2_resp)); | |
409 | ses->server->mac_signing_key.len = 16 + sizeof(struct ntlmv2_resp); | |
410 | } | |
411 | ||
412 | void CalcNTLMv2_response(const struct cifsSesInfo *ses, | |
413 | char *v2_session_response) | |
414 | { | |
415 | struct HMACMD5Context context; | |
416 | /* rest of v2 struct already generated */ | |
417 | memcpy(v2_session_response + 8, ses->server->cryptKey, 8); | |
418 | hmac_md5_init_limK_to_64(ses->server->ntlmv2_hash, 16, &context); | |
419 | ||
420 | hmac_md5_update(v2_session_response+8, | |
421 | sizeof(struct ntlmv2_resp) - 8, &context); | |
422 | ||
423 | hmac_md5_final(v2_session_response, &context); | |
424 | /* cifs_dump_mem("v2_sess_rsp: ", v2_session_response, 32); */ | |
425 | } |