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1da177e4 LT |
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 | #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, 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 | ||
ad009ac9 | 53 | int cifs_sign_smb(struct smb_hdr * cifs_pdu, struct TCP_Server_Info * server, |
1da177e4 LT |
54 | __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 | ||
ad009ac9 | 62 | if((cifs_pdu == NULL) || (server == NULL)) |
1da177e4 LT |
63 | return -EINVAL; |
64 | ||
65 | if((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0) | |
66 | return rc; | |
67 | ||
68 | spin_lock(&GlobalMid_Lock); | |
ad009ac9 | 69 | cifs_pdu->Signature.Sequence.SequenceNumber = cpu_to_le32(server->sequence_number); |
1da177e4 LT |
70 | cifs_pdu->Signature.Sequence.Reserved = 0; |
71 | ||
ad009ac9 SF |
72 | *pexpected_response_sequence_number = server->sequence_number++; |
73 | server->sequence_number++; | |
1da177e4 LT |
74 | spin_unlock(&GlobalMid_Lock); |
75 | ||
ad009ac9 | 76 | rc = cifs_calculate_signature(cifs_pdu, server->mac_signing_key,smb_signature); |
1da177e4 LT |
77 | 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 | ||
85 | int 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 */ | |
135 | int 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 | ||
147 | int 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; | |
152 | wchar_t * unicode_buf; | |
153 | 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 | ||
ad009ac9 | 193 | hmac_md5_final(ses->server->mac_signing_key,&ctx); |
1da177e4 LT |
194 | kfree(ucase_buf); |
195 | kfree(unicode_buf); | |
196 | return 0; | |
197 | } | |
198 | void 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); */ | |
ad009ac9 | 203 | hmac_md5_init_limK_to_64(ses->server->mac_signing_key, 16, &context); |
1da177e4 LT |
204 | |
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 | } |