blob: fe2bb7c4c9121c4bcc2cfeeb5ca9ec9669bcc944 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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#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
36extern void mdfour(unsigned char *out, unsigned char *in, int n);
37extern void E_md4hash(const unsigned char *passwd, unsigned char *p16);
38
39static int cifs_calculate_signature(const struct smb_hdr * cifs_pdu, const char * key, char * signature)
40{
41 struct MD5Context context;
42
43 if((cifs_pdu == NULL) || (signature == NULL))
44 return -EINVAL;
45
46 MD5Init(&context);
47 MD5Update(&context,key,CIFS_SESSION_KEY_SIZE+16);
48 MD5Update(&context,cifs_pdu->Protocol,cifs_pdu->smb_buf_length);
49 MD5Final(signature,&context);
50 return 0;
51}
52
Steve Frenchad009ac2005-04-28 22:41:05 -070053int cifs_sign_smb(struct smb_hdr * cifs_pdu, struct TCP_Server_Info * server,
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 __u32 * pexpected_response_sequence_number)
55{
56 int rc = 0;
57 char smb_signature[20];
58
59 /* BB remember to initialize sequence number elsewhere and initialize mac_signing key elsewhere BB */
60 /* BB remember to add code to save expected sequence number in midQ entry BB */
61
Steve Frenchad009ac2005-04-28 22:41:05 -070062 if((cifs_pdu == NULL) || (server == NULL))
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 return -EINVAL;
64
65 if((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0)
66 return rc;
67
68 spin_lock(&GlobalMid_Lock);
Steve Frenchad009ac2005-04-28 22:41:05 -070069 cifs_pdu->Signature.Sequence.SequenceNumber = cpu_to_le32(server->sequence_number);
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 cifs_pdu->Signature.Sequence.Reserved = 0;
71
Steve Frenchad009ac2005-04-28 22:41:05 -070072 *pexpected_response_sequence_number = server->sequence_number++;
73 server->sequence_number++;
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 spin_unlock(&GlobalMid_Lock);
75
Steve Frenchad009ac2005-04-28 22:41:05 -070076 rc = cifs_calculate_signature(cifs_pdu, server->mac_signing_key,smb_signature);
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 if(rc)
78 memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
79 else
80 memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);
81
82 return rc;
83}
84
85int cifs_verify_signature(struct smb_hdr * cifs_pdu, const char * mac_key,
86 __u32 expected_sequence_number)
87{
88 unsigned int rc;
89 char server_response_sig[8];
90 char what_we_think_sig_should_be[20];
91
92 if((cifs_pdu == NULL) || (mac_key == NULL))
93 return -EINVAL;
94
95 if (cifs_pdu->Command == SMB_COM_NEGOTIATE)
96 return 0;
97
98 if (cifs_pdu->Command == SMB_COM_LOCKING_ANDX) {
99 struct smb_com_lock_req * pSMB = (struct smb_com_lock_req *)cifs_pdu;
100 if(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE)
101 return 0;
102 }
103
104 /* BB what if signatures are supposed to be on for session but server does not
105 send one? BB */
106
107 /* Do not need to verify session setups with signature "BSRSPYL " */
108 if(memcmp(cifs_pdu->Signature.SecuritySignature,"BSRSPYL ",8)==0)
109 cFYI(1,("dummy signature received for smb command 0x%x",cifs_pdu->Command));
110
111 /* save off the origiginal signature so we can modify the smb and check
112 its signature against what the server sent */
113 memcpy(server_response_sig,cifs_pdu->Signature.SecuritySignature,8);
114
115 cifs_pdu->Signature.Sequence.SequenceNumber = cpu_to_le32(expected_sequence_number);
116 cifs_pdu->Signature.Sequence.Reserved = 0;
117
118 rc = cifs_calculate_signature(cifs_pdu, mac_key,
119 what_we_think_sig_should_be);
120
121 if(rc)
122 return rc;
123
124
125/* cifs_dump_mem("what we think it should be: ",what_we_think_sig_should_be,16); */
126
127 if(memcmp(server_response_sig, what_we_think_sig_should_be, 8))
128 return -EACCES;
129 else
130 return 0;
131
132}
133
134/* We fill in key by putting in 40 byte array which was allocated by caller */
135int cifs_calculate_mac_key(char * key, const char * rn, const char * password)
136{
137 char temp_key[16];
138 if ((key == NULL) || (rn == NULL))
139 return -EINVAL;
140
141 E_md4hash(password, temp_key);
142 mdfour(key,temp_key,16);
143 memcpy(key+16,rn, CIFS_SESSION_KEY_SIZE);
144 return 0;
145}
146
147int CalcNTLMv2_partial_mac_key(struct cifsSesInfo * ses, struct nls_table * nls_info)
148{
149 char temp_hash[16];
150 struct HMACMD5Context ctx;
151 char * ucase_buf;
Steve Frenche89dc922005-11-11 15:18:19 -0800152 __le16 * unicode_buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 unsigned int i,user_name_len,dom_name_len;
154
155 if(ses == NULL)
156 return -EINVAL;
157
158 E_md4hash(ses->password, temp_hash);
159
160 hmac_md5_init_limK_to_64(temp_hash, 16, &ctx);
161 user_name_len = strlen(ses->userName);
162 if(user_name_len > MAX_USERNAME_SIZE)
163 return -EINVAL;
164 dom_name_len = strlen(ses->domainName);
165 if(dom_name_len > MAX_USERNAME_SIZE)
166 return -EINVAL;
167
168 ucase_buf = kmalloc((MAX_USERNAME_SIZE+1), GFP_KERNEL);
169 if(ucase_buf == NULL)
170 return -ENOMEM;
171 unicode_buf = kmalloc((MAX_USERNAME_SIZE+1)*4, GFP_KERNEL);
172 if(unicode_buf == NULL) {
173 kfree(ucase_buf);
174 return -ENOMEM;
175 }
176
177 for(i=0;i<user_name_len;i++)
178 ucase_buf[i] = nls_info->charset2upper[(int)ses->userName[i]];
179 ucase_buf[i] = 0;
180 user_name_len = cifs_strtoUCS(unicode_buf, ucase_buf, MAX_USERNAME_SIZE*2, nls_info);
181 unicode_buf[user_name_len] = 0;
182 user_name_len++;
183
184 for(i=0;i<dom_name_len;i++)
185 ucase_buf[i] = nls_info->charset2upper[(int)ses->domainName[i]];
186 ucase_buf[i] = 0;
187 dom_name_len = cifs_strtoUCS(unicode_buf+user_name_len, ucase_buf, MAX_USERNAME_SIZE*2, nls_info);
188
189 unicode_buf[user_name_len + dom_name_len] = 0;
190 hmac_md5_update((const unsigned char *) unicode_buf,
191 (user_name_len+dom_name_len)*2,&ctx);
192
Steve Frenchad009ac2005-04-28 22:41:05 -0700193 hmac_md5_final(ses->server->mac_signing_key,&ctx);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 kfree(ucase_buf);
195 kfree(unicode_buf);
196 return 0;
197}
198void CalcNTLMv2_response(const struct cifsSesInfo * ses,char * v2_session_response)
199{
200 struct HMACMD5Context context;
201 memcpy(v2_session_response + 8, ses->server->cryptKey,8);
202 /* gen_blob(v2_session_response + 16); */
Steve Frenchad009ac2005-04-28 22:41:05 -0700203 hmac_md5_init_limK_to_64(ses->server->mac_signing_key, 16, &context);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204
205 hmac_md5_update(ses->server->cryptKey,8,&context);
206/* hmac_md5_update(v2_session_response+16)client thing,8,&context); */ /* BB fix */
207
208 hmac_md5_final(v2_session_response,&context);
209}