Merge with /pub/scm/linux/kernel/git/torvalds/linux-2.6.git
[sfrench/cifs-2.6.git] / fs / cifs / cifsencrypt.c
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
30 /* Calculate and return the CIFS signature based on the mac key and the smb pdu */
31 /* the 16 byte signature must be allocated by the caller  */
32 /* Note we only use the 1st eight bytes */
33 /* Note that the smb header signature field on input contains the  
34         sequence number before this function is called */
35
36 extern void mdfour(unsigned char *out, unsigned char *in, int n);
37 extern void E_md4hash(const unsigned char *passwd, unsigned char *p16);
38         
39 static int cifs_calculate_signature(const struct smb_hdr * cifs_pdu, 
40                                     const char * key, char * signature)
41 {
42         struct  MD5Context context;
43
44         if((cifs_pdu == NULL) || (signature == NULL))
45                 return -EINVAL;
46
47         MD5Init(&context);
48         MD5Update(&context,key,CIFS_SESSION_KEY_SIZE+16);
49         MD5Update(&context,cifs_pdu->Protocol,cifs_pdu->smb_buf_length);
50         MD5Final(signature,&context);
51         return 0;
52 }
53
54 int cifs_sign_smb(struct smb_hdr * cifs_pdu, struct TCP_Server_Info * server,
55         __u32 * pexpected_response_sequence_number)
56 {
57         int rc = 0;
58         char smb_signature[20];
59
60         /* BB remember to initialize sequence number elsewhere and initialize mac_signing key elsewhere BB */
61         /* BB remember to add code to save expected sequence number in midQ entry BB */
62
63         if((cifs_pdu == NULL) || (server == NULL))
64                 return -EINVAL;
65
66         if((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0) 
67                 return rc;
68
69         spin_lock(&GlobalMid_Lock);
70         cifs_pdu->Signature.Sequence.SequenceNumber = cpu_to_le32(server->sequence_number);
71         cifs_pdu->Signature.Sequence.Reserved = 0;
72         
73         *pexpected_response_sequence_number = server->sequence_number++;
74         server->sequence_number++;
75         spin_unlock(&GlobalMid_Lock);
76
77         rc = cifs_calculate_signature(cifs_pdu, server->mac_signing_key,smb_signature);
78         if(rc)
79                 memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
80         else
81                 memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);
82
83         return rc;
84 }
85
86 static int cifs_calc_signature2(const struct kvec * iov, int n_vec,
87                                 const char * key, char * signature)
88 {
89         struct  MD5Context context;
90
91         if((iov == NULL) || (signature == NULL))
92                 return -EINVAL;
93
94         MD5Init(&context);
95         MD5Update(&context,key,CIFS_SESSION_KEY_SIZE+16);
96
97 /*        MD5Update(&context,cifs_pdu->Protocol,cifs_pdu->smb_buf_length); */ /* BB FIXME BB */
98
99         MD5Final(signature,&context);
100
101         return -EOPNOTSUPP;
102 /*        return 0; */
103 }
104
105
106 int cifs_sign_smb2(struct kvec * iov, int n_vec, struct TCP_Server_Info *server,
107                    __u32 * pexpected_response_sequence_number)
108 {
109         int rc = 0;
110         char smb_signature[20];
111         struct smb_hdr * cifs_pdu = iov[0].iov_base;
112
113         if((cifs_pdu == NULL) || (server == NULL))
114                 return -EINVAL;
115
116         if((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0)
117                 return rc;
118
119         spin_lock(&GlobalMid_Lock);
120         cifs_pdu->Signature.Sequence.SequenceNumber = 
121                                 cpu_to_le32(server->sequence_number);
122         cifs_pdu->Signature.Sequence.Reserved = 0;
123
124         *pexpected_response_sequence_number = server->sequence_number++;
125         server->sequence_number++;
126         spin_unlock(&GlobalMid_Lock);
127
128         rc = cifs_calc_signature2(iov, n_vec, server->mac_signing_key,
129                                       smb_signature);
130         if(rc)
131                 memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
132         else
133                 memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);
134
135         return rc;
136
137 }
138
139 int cifs_verify_signature(struct smb_hdr * cifs_pdu, const char * mac_key,
140         __u32 expected_sequence_number)
141 {
142         unsigned int rc;
143         char server_response_sig[8];
144         char what_we_think_sig_should_be[20];
145
146         if((cifs_pdu == NULL) || (mac_key == NULL))
147                 return -EINVAL;
148
149         if (cifs_pdu->Command == SMB_COM_NEGOTIATE)
150                 return 0;
151
152         if (cifs_pdu->Command == SMB_COM_LOCKING_ANDX) {
153                 struct smb_com_lock_req * pSMB = (struct smb_com_lock_req *)cifs_pdu;
154             if(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE)
155                         return 0;
156         }
157
158         /* BB what if signatures are supposed to be on for session but server does not
159                 send one? BB */
160         
161         /* Do not need to verify session setups with signature "BSRSPYL "  */
162         if(memcmp(cifs_pdu->Signature.SecuritySignature,"BSRSPYL ",8)==0)
163                 cFYI(1,("dummy signature received for smb command 0x%x",cifs_pdu->Command));
164
165         /* save off the origiginal signature so we can modify the smb and check
166                 its signature against what the server sent */
167         memcpy(server_response_sig,cifs_pdu->Signature.SecuritySignature,8);
168
169         cifs_pdu->Signature.Sequence.SequenceNumber = cpu_to_le32(expected_sequence_number);
170         cifs_pdu->Signature.Sequence.Reserved = 0;
171
172         rc = cifs_calculate_signature(cifs_pdu, mac_key,
173                 what_we_think_sig_should_be);
174
175         if(rc)
176                 return rc;
177
178         
179 /*      cifs_dump_mem("what we think it should be: ",what_we_think_sig_should_be,16); */
180
181         if(memcmp(server_response_sig, what_we_think_sig_should_be, 8))
182                 return -EACCES;
183         else
184                 return 0;
185
186 }
187
188 /* We fill in key by putting in 40 byte array which was allocated by caller */
189 int cifs_calculate_mac_key(char * key, const char * rn, const char * password)
190 {
191         char temp_key[16];
192         if ((key == NULL) || (rn == NULL))
193                 return -EINVAL;
194
195         E_md4hash(password, temp_key);
196         mdfour(key,temp_key,16);
197         memcpy(key+16,rn, CIFS_SESSION_KEY_SIZE);
198         return 0;
199 }
200
201 int CalcNTLMv2_partial_mac_key(struct cifsSesInfo * ses, struct nls_table * nls_info)
202 {
203         char temp_hash[16];
204         struct HMACMD5Context ctx;
205         char * ucase_buf;
206         __le16 * unicode_buf;
207         unsigned int i,user_name_len,dom_name_len;
208
209         if(ses == NULL)
210                 return -EINVAL;
211
212         E_md4hash(ses->password, temp_hash);
213
214         hmac_md5_init_limK_to_64(temp_hash, 16, &ctx);
215         user_name_len = strlen(ses->userName);
216         if(user_name_len > MAX_USERNAME_SIZE)
217                 return -EINVAL;
218         dom_name_len = strlen(ses->domainName);
219         if(dom_name_len > MAX_USERNAME_SIZE)
220                 return -EINVAL;
221   
222         ucase_buf = kmalloc((MAX_USERNAME_SIZE+1), GFP_KERNEL);
223         if(ucase_buf == NULL)
224                 return -ENOMEM;
225         unicode_buf = kmalloc((MAX_USERNAME_SIZE+1)*4, GFP_KERNEL);
226         if(unicode_buf == NULL) {
227                 kfree(ucase_buf);
228                 return -ENOMEM;
229         }
230    
231         for(i=0;i<user_name_len;i++)
232                 ucase_buf[i] = nls_info->charset2upper[(int)ses->userName[i]];
233         ucase_buf[i] = 0;
234         user_name_len = cifs_strtoUCS(unicode_buf, ucase_buf, MAX_USERNAME_SIZE*2, nls_info);
235         unicode_buf[user_name_len] = 0;
236         user_name_len++;
237
238         for(i=0;i<dom_name_len;i++)
239                 ucase_buf[i] = nls_info->charset2upper[(int)ses->domainName[i]];
240         ucase_buf[i] = 0;
241         dom_name_len = cifs_strtoUCS(unicode_buf+user_name_len, ucase_buf, MAX_USERNAME_SIZE*2, nls_info);
242
243         unicode_buf[user_name_len + dom_name_len] = 0;
244         hmac_md5_update((const unsigned char *) unicode_buf,
245                 (user_name_len+dom_name_len)*2,&ctx);
246
247         hmac_md5_final(ses->server->mac_signing_key,&ctx);
248         kfree(ucase_buf);
249         kfree(unicode_buf);
250         return 0;
251 }
252 void CalcNTLMv2_response(const struct cifsSesInfo * ses,char * v2_session_response)
253 {
254         struct HMACMD5Context context;
255         memcpy(v2_session_response + 8, ses->server->cryptKey,8);
256         /* gen_blob(v2_session_response + 16); */
257         hmac_md5_init_limK_to_64(ses->server->mac_signing_key, 16, &context);
258
259         hmac_md5_update(ses->server->cryptKey,8,&context);
260 /*      hmac_md5_update(v2_session_response+16)client thing,8,&context); */ /* BB fix */
261
262         hmac_md5_final(v2_session_response,&context);
263         cifs_dump_mem("v2_sess_rsp: ", v2_session_response, 32); /* BB removeme BB */
264 }