1 /*
2 * fs/cifs/cifsencrypt.c
3 *
4 * Copyright (C) International Business Machines Corp., 2003
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
29 /* Calculate and return the CIFS signature based on the mac key and the smb pdu */
30 /* the 16 byte signature must be allocated by the caller */
31 /* Note we only use the 1st eight bytes */
32 /* Note that the smb header signature field on input contains the
33 sequence number before this function is called */
34
35 extern void mdfour(unsigned char *out, unsigned char *in, int n);
36 extern void E_md4hash(const unsigned char *passwd, unsigned char *p16);
37
38 static int cifs_calculate_signature(const struct smb_hdr * cifs_pdu, const char * key, char * signature)
39 {
40 struct MD5Context context;
41
42 if((cifs_pdu == NULL) || (signature == NULL))
43 return -EINVAL;
44
45 MD5Init(&context);
46 MD5Update(&context,key,CIFS_SESSION_KEY_SIZE+16);
47 MD5Update(&context,cifs_pdu->Protocol,cifs_pdu->smb_buf_length);
48 MD5Final(signature,&context);
49 return 0;
50 }
51
52 int cifs_sign_smb(struct smb_hdr * cifs_pdu, struct cifsSesInfo * ses,
53 __u32 * pexpected_response_sequence_number)
54 {
55 int rc = 0;
56 char smb_signature[20];
57
58 /* BB remember to initialize sequence number elsewhere and initialize mac_signing key elsewhere BB */
59 /* BB remember to add code to save expected sequence number in midQ entry BB */
60
61 if((cifs_pdu == NULL) || (ses == NULL))
62 return -EINVAL;
63
64 if((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0)
65 return rc;
66
67 spin_lock(&GlobalMid_Lock);
68 cifs_pdu->Signature.Sequence.SequenceNumber = cpu_to_le32(ses->sequence_number);
69 cifs_pdu->Signature.Sequence.Reserved = 0;
70
71 *pexpected_response_sequence_number = ses->sequence_number++;
72 ses->sequence_number++;
73 spin_unlock(&GlobalMid_Lock);
74
75 rc = cifs_calculate_signature(cifs_pdu, ses->mac_signing_key,smb_signature);
76 if(rc)
77 memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
78 else
79 memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);
80
81 return rc;
82 }
83
84 int cifs_verify_signature(struct smb_hdr * cifs_pdu, const char * mac_key,
85 __u32 expected_sequence_number)
86 {
87 unsigned int rc;
88 char server_response_sig[8];
89 char what_we_think_sig_should_be[20];
90
91 if((cifs_pdu == NULL) || (mac_key == NULL))
92 return -EINVAL;
93
94 if (cifs_pdu->Command == SMB_COM_NEGOTIATE)
95 return 0;
96
97 if (cifs_pdu->Command == SMB_COM_LOCKING_ANDX) {
98 struct smb_com_lock_req * pSMB = (struct smb_com_lock_req *)cifs_pdu;
99 if(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE)
100 return 0;
101 }
102
103 /* BB what if signatures are supposed to be on for session but server does not
104 send one? BB */
105
106 /* Do not need to verify session setups with signature "BSRSPYL " */
107 if(memcmp(cifs_pdu->Signature.SecuritySignature,"BSRSPYL ",8)==0)
108 cFYI(1,("dummy signature received for smb command 0x%x",cifs_pdu->Command));
109
110 /* save off the origiginal signature so we can modify the smb and check
111 its signature against what the server sent */
112 memcpy(server_response_sig,cifs_pdu->Signature.SecuritySignature,8);
113
114 cifs_pdu->Signature.Sequence.SequenceNumber = cpu_to_le32(expected_sequence_number);
115 cifs_pdu->Signature.Sequence.Reserved = 0;
116
117 rc = cifs_calculate_signature(cifs_pdu, mac_key,
118 what_we_think_sig_should_be);
119
120 if(rc)
121 return rc;
122
123
124 /* cifs_dump_mem("what we think it should be: ",what_we_think_sig_should_be,16); */
125
126 if(memcmp(server_response_sig, what_we_think_sig_should_be, 8))
127 return -EACCES;
128 else
129 return 0;
130
131 }
132
133 /* We fill in key by putting in 40 byte array which was allocated by caller */
134 int cifs_calculate_mac_key(char * key, const char * rn, const char * password)
135 {
136 char temp_key[16];
137 if ((key == NULL) || (rn == NULL))
138 return -EINVAL;
139
140 E_md4hash(password, temp_key);
141 mdfour(key,temp_key,16);
142 memcpy(key+16,rn, CIFS_SESSION_KEY_SIZE);
143 return 0;
144 }
145
146 int CalcNTLMv2_partial_mac_key(struct cifsSesInfo * ses, struct nls_table * nls_info)
147 {
148 char temp_hash[16];
149 struct HMACMD5Context ctx;
150 char * ucase_buf;
151 wchar_t * unicode_buf;
152 unsigned int i,user_name_len,dom_name_len;
153
154 if(ses == NULL)
155 return -EINVAL;
156
157 E_md4hash(ses->password, temp_hash);
158
159 hmac_md5_init_limK_to_64(temp_hash, 16, &ctx);
160 user_name_len = strlen(ses->userName);
161 if(user_name_len > MAX_USERNAME_SIZE)
162 return -EINVAL;
163 dom_name_len = strlen(ses->domainName);
164 if(dom_name_len > MAX_USERNAME_SIZE)
165 return -EINVAL;
166
167 ucase_buf = kmalloc((MAX_USERNAME_SIZE+1), GFP_KERNEL);
168 if(ucase_buf == NULL)
169 return -ENOMEM;
170 unicode_buf = kmalloc((MAX_USERNAME_SIZE+1)*4, GFP_KERNEL);
171 if(unicode_buf == NULL) {
172 kfree(ucase_buf);
173 return -ENOMEM;
174 }
175
176 for(i=0;i<user_name_len;i++)
177 ucase_buf[i] = nls_info->charset2upper[(int)ses->userName[i]];
178 ucase_buf[i] = 0;
179 user_name_len = cifs_strtoUCS(unicode_buf, ucase_buf, MAX_USERNAME_SIZE*2, nls_info);
180 unicode_buf[user_name_len] = 0;
181 user_name_len++;
182
183 for(i=0;i<dom_name_len;i++)
184 ucase_buf[i] = nls_info->charset2upper[(int)ses->domainName[i]];
185 ucase_buf[i] = 0;
186 dom_name_len = cifs_strtoUCS(unicode_buf+user_name_len, ucase_buf, MAX_USERNAME_SIZE*2, nls_info);
187
188 unicode_buf[user_name_len + dom_name_len] = 0;
189 hmac_md5_update((const unsigned char *) unicode_buf,
190 (user_name_len+dom_name_len)*2,&ctx);
191
192 hmac_md5_final(ses->mac_signing_key,&ctx);
193 kfree(ucase_buf);
194 kfree(unicode_buf);
195 return 0;
196 }
197 void CalcNTLMv2_response(const struct cifsSesInfo * ses,char * v2_session_response)
198 {
199 struct HMACMD5Context context;
200 memcpy(v2_session_response + 8, ses->server->cryptKey,8);
201 /* gen_blob(v2_session_response + 16); */
202 hmac_md5_init_limK_to_64(ses->mac_signing_key, 16, &context);
203
204 hmac_md5_update(ses->server->cryptKey,8,&context);
205 /* hmac_md5_update(v2_session_response+16)client thing,8,&context); */ /* BB fix */
206
207 hmac_md5_final(v2_session_response,&context);
208 }
209
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