2 * fs/cifs/cifsencrypt.c
4 * Copyright (C) International Business Machines Corp., 2005,2006
5 * Author(s): Steve French (sfrench@us.ibm.com)
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.
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.
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
23 #include <linux/slab.h>
26 #include "cifs_debug.h"
28 #include "cifs_unicode.h"
29 #include "cifsproto.h"
30 #include <linux/ctype.h>
31 #include <linux/random.h>
33 /* Calculate and return the CIFS signature based on the mac key and SMB PDU */
34 /* the 16 byte signature must be allocated by the caller */
35 /* Note we only use the 1st eight bytes */
36 /* Note that the smb header signature field on input contains the
37 sequence number before this function is called */
39 extern void mdfour(unsigned char *out, unsigned char *in, int n);
40 extern void E_md4hash(const unsigned char *passwd, unsigned char *p16);
41 extern void SMBencrypt(unsigned char *passwd, const unsigned char *c8,
44 static int cifs_calculate_signature(const struct smb_hdr *cifs_pdu,
45 const struct mac_key *key, char *signature)
47 struct MD5Context context;
49 if ((cifs_pdu == NULL) || (signature == NULL) || (key == NULL))
52 cifs_MD5_init(&context);
53 cifs_MD5_update(&context, (char *)&key->data, key->len);
54 cifs_MD5_update(&context, cifs_pdu->Protocol, cifs_pdu->smb_buf_length);
56 cifs_MD5_final(signature, &context);
60 int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server,
61 __u32 *pexpected_response_sequence_number)
64 char smb_signature[20];
66 if ((cifs_pdu == NULL) || (server == NULL))
69 if ((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0)
72 spin_lock(&GlobalMid_Lock);
73 cifs_pdu->Signature.Sequence.SequenceNumber =
74 cpu_to_le32(server->sequence_number);
75 cifs_pdu->Signature.Sequence.Reserved = 0;
77 *pexpected_response_sequence_number = server->sequence_number++;
78 server->sequence_number++;
79 spin_unlock(&GlobalMid_Lock);
81 rc = cifs_calculate_signature(cifs_pdu, &server->mac_signing_key,
84 memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
86 memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);
91 static int cifs_calc_signature2(const struct kvec *iov, int n_vec,
92 const struct mac_key *key, char *signature)
94 struct MD5Context context;
97 if ((iov == NULL) || (signature == NULL) || (key == NULL))
100 cifs_MD5_init(&context);
101 cifs_MD5_update(&context, (char *)&key->data, key->len);
102 for (i = 0; i < n_vec; i++) {
103 if (iov[i].iov_len == 0)
105 if (iov[i].iov_base == NULL) {
106 cERROR(1, "null iovec entry");
109 /* The first entry includes a length field (which does not get
110 signed that occupies the first 4 bytes before the header */
112 if (iov[0].iov_len <= 8) /* cmd field at offset 9 */
113 break; /* nothing to sign or corrupt header */
114 cifs_MD5_update(&context, iov[0].iov_base+4,
117 cifs_MD5_update(&context, iov[i].iov_base, iov[i].iov_len);
120 cifs_MD5_final(signature, &context);
126 int cifs_sign_smb2(struct kvec *iov, int n_vec, struct TCP_Server_Info *server,
127 __u32 *pexpected_response_sequence_number)
130 char smb_signature[20];
131 struct smb_hdr *cifs_pdu = iov[0].iov_base;
133 if ((cifs_pdu == NULL) || (server == NULL))
136 if ((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0)
139 spin_lock(&GlobalMid_Lock);
140 cifs_pdu->Signature.Sequence.SequenceNumber =
141 cpu_to_le32(server->sequence_number);
142 cifs_pdu->Signature.Sequence.Reserved = 0;
144 *pexpected_response_sequence_number = server->sequence_number++;
145 server->sequence_number++;
146 spin_unlock(&GlobalMid_Lock);
148 rc = cifs_calc_signature2(iov, n_vec, &server->mac_signing_key,
151 memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
153 memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);
158 int cifs_verify_signature(struct smb_hdr *cifs_pdu,
159 const struct mac_key *mac_key,
160 __u32 expected_sequence_number)
163 char server_response_sig[8];
164 char what_we_think_sig_should_be[20];
166 if ((cifs_pdu == NULL) || (mac_key == NULL))
169 if (cifs_pdu->Command == SMB_COM_NEGOTIATE)
172 if (cifs_pdu->Command == SMB_COM_LOCKING_ANDX) {
173 struct smb_com_lock_req *pSMB =
174 (struct smb_com_lock_req *)cifs_pdu;
175 if (pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE)
179 /* BB what if signatures are supposed to be on for session but
180 server does not send one? BB */
182 /* Do not need to verify session setups with signature "BSRSPYL " */
183 if (memcmp(cifs_pdu->Signature.SecuritySignature, "BSRSPYL ", 8) == 0)
184 cFYI(1, "dummy signature received for smb command 0x%x",
187 /* save off the origiginal signature so we can modify the smb and check
188 its signature against what the server sent */
189 memcpy(server_response_sig, cifs_pdu->Signature.SecuritySignature, 8);
191 cifs_pdu->Signature.Sequence.SequenceNumber =
192 cpu_to_le32(expected_sequence_number);
193 cifs_pdu->Signature.Sequence.Reserved = 0;
195 rc = cifs_calculate_signature(cifs_pdu, mac_key,
196 what_we_think_sig_should_be);
201 /* cifs_dump_mem("what we think it should be: ",
202 what_we_think_sig_should_be, 16); */
204 if (memcmp(server_response_sig, what_we_think_sig_should_be, 8))
211 /* We fill in key by putting in 40 byte array which was allocated by caller */
212 int cifs_calculate_mac_key(struct mac_key *key, const char *rn,
213 const char *password)
216 if ((key == NULL) || (rn == NULL))
219 E_md4hash(password, temp_key);
220 mdfour(key->data.ntlm, temp_key, 16);
221 memcpy(key->data.ntlm+16, rn, CIFS_SESS_KEY_SIZE);
226 #ifdef CONFIG_CIFS_WEAK_PW_HASH
227 void calc_lanman_hash(const char *password, const char *cryptkey, bool encrypt,
228 char *lnm_session_key)
231 char password_with_pad[CIFS_ENCPWD_SIZE];
233 memset(password_with_pad, 0, CIFS_ENCPWD_SIZE);
235 strncpy(password_with_pad, password, CIFS_ENCPWD_SIZE);
237 if (!encrypt && global_secflags & CIFSSEC_MAY_PLNTXT) {
238 memset(lnm_session_key, 0, CIFS_SESS_KEY_SIZE);
239 memcpy(lnm_session_key, password_with_pad,
244 /* calculate old style session key */
245 /* calling toupper is less broken than repeatedly
246 calling nls_toupper would be since that will never
247 work for UTF8, but neither handles multibyte code pages
248 but the only alternative would be converting to UCS-16 (Unicode)
249 (using a routine something like UniStrupr) then
250 uppercasing and then converting back from Unicode - which
251 would only worth doing it if we knew it were utf8. Basically
252 utf8 and other multibyte codepages each need their own strupper
253 function since a byte at a time will ont work. */
255 for (i = 0; i < CIFS_ENCPWD_SIZE; i++)
256 password_with_pad[i] = toupper(password_with_pad[i]);
258 SMBencrypt(password_with_pad, cryptkey, lnm_session_key);
260 /* clear password before we return/free memory */
261 memset(password_with_pad, 0, CIFS_ENCPWD_SIZE);
263 #endif /* CIFS_WEAK_PW_HASH */
265 static int calc_ntlmv2_hash(struct cifsSesInfo *ses,
266 const struct nls_table *nls_cp)
271 struct HMACMD5Context *pctxt;
275 pctxt = kmalloc(sizeof(struct HMACMD5Context), GFP_KERNEL);
280 /* calculate md4 hash of password */
281 E_md4hash(ses->password, nt_hash);
283 /* convert Domainname to unicode and uppercase */
284 hmac_md5_init_limK_to_64(nt_hash, 16, pctxt);
286 /* convert ses->userName to unicode and uppercase */
287 len = strlen(ses->userName);
288 user = kmalloc(2 + (len * 2), GFP_KERNEL);
291 len = cifs_strtoUCS((__le16 *)user, ses->userName, len, nls_cp);
293 hmac_md5_update((char *)user, 2*len, pctxt);
295 /* convert ses->domainName to unicode and uppercase */
296 if (ses->domainName) {
297 len = strlen(ses->domainName);
299 domain = kmalloc(2 + (len * 2), GFP_KERNEL);
302 len = cifs_strtoUCS((__le16 *)domain, ses->domainName, len,
304 /* the following line was removed since it didn't work well
305 with lower cased domain name that passed as an option.
306 Maybe converting the domain name earlier makes sense */
307 /* UniStrupr(domain); */
309 hmac_md5_update((char *)domain, 2*len, pctxt);
316 /* BB FIXME what about bytes 24 through 40 of the signing key?
317 compare with the NTLM example */
318 hmac_md5_final(ses->server->ntlmv2_hash, pctxt);
324 void setup_ntlmv2_rsp(struct cifsSesInfo *ses, char *resp_buf,
325 const struct nls_table *nls_cp)
328 struct ntlmv2_resp *buf = (struct ntlmv2_resp *)resp_buf;
329 struct HMACMD5Context context;
331 buf->blob_signature = cpu_to_le32(0x00000101);
333 buf->time = cpu_to_le64(cifs_UnixTimeToNT(CURRENT_TIME));
334 get_random_bytes(&buf->client_chal, sizeof(buf->client_chal));
336 buf->names[0].type = cpu_to_le16(NTLMSSP_DOMAIN_TYPE);
337 buf->names[0].length = 0;
338 buf->names[1].type = 0;
339 buf->names[1].length = 0;
341 /* calculate buf->ntlmv2_hash */
342 rc = calc_ntlmv2_hash(ses, nls_cp);
344 cERROR(1, "could not get v2 hash rc %d", rc);
345 CalcNTLMv2_response(ses, resp_buf);
347 /* now calculate the MAC key for NTLMv2 */
348 hmac_md5_init_limK_to_64(ses->server->ntlmv2_hash, 16, &context);
349 hmac_md5_update(resp_buf, 16, &context);
350 hmac_md5_final(ses->server->mac_signing_key.data.ntlmv2.key, &context);
352 memcpy(&ses->server->mac_signing_key.data.ntlmv2.resp, resp_buf,
353 sizeof(struct ntlmv2_resp));
354 ses->server->mac_signing_key.len = 16 + sizeof(struct ntlmv2_resp);
357 void CalcNTLMv2_response(const struct cifsSesInfo *ses,
358 char *v2_session_response)
360 struct HMACMD5Context context;
361 /* rest of v2 struct already generated */
362 memcpy(v2_session_response + 8, ses->server->cryptKey, 8);
363 hmac_md5_init_limK_to_64(ses->server->ntlmv2_hash, 16, &context);
365 hmac_md5_update(v2_session_response+8,
366 sizeof(struct ntlmv2_resp) - 8, &context);
368 hmac_md5_final(v2_session_response, &context);
369 /* cifs_dump_mem("v2_sess_rsp: ", v2_session_response, 32); */