summaryrefslogtreecommitdiff
path: root/fs/cifs/cifsencrypt.c
blob: 41d08d9fef79ecc305af42f6862a3c302acc9ef5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
/*
 *   fs/cifs/cifsencrypt.c
 *
 *   Copyright (C) International Business Machines  Corp., 2005,2006
 *   Author(s): Steve French (sfrench@us.ibm.com)
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published
 *   by the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   This library is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/fs.h>
#include "cifspdu.h"
#include "cifsglob.h" 
#include "cifs_debug.h"
#include "md5.h"
#include "cifs_unicode.h"
#include "cifsproto.h"

/* Calculate and return the CIFS signature based on the mac key and the smb pdu */
/* the 16 byte signature must be allocated by the caller  */
/* Note we only use the 1st eight bytes */
/* Note that the smb header signature field on input contains the  
	sequence number before this function is called */

extern void mdfour(unsigned char *out, unsigned char *in, int n);
extern void E_md4hash(const unsigned char *passwd, unsigned char *p16);
	
static int cifs_calculate_signature(const struct smb_hdr * cifs_pdu, 
				    const char * key, char * signature)
{
	struct	MD5Context context;

	if((cifs_pdu == NULL) || (signature == NULL))
		return -EINVAL;

	MD5Init(&context);
	MD5Update(&context,key,CIFS_SESSION_KEY_SIZE+16);
	MD5Update(&context,cifs_pdu->Protocol,cifs_pdu->smb_buf_length);
	MD5Final(signature,&context);
	return 0;
}

int cifs_sign_smb(struct smb_hdr * cifs_pdu, struct TCP_Server_Info * server,
	__u32 * pexpected_response_sequence_number)
{
	int rc = 0;
	char smb_signature[20];

	/* BB remember to initialize sequence number elsewhere and initialize mac_signing key elsewhere BB */
	/* BB remember to add code to save expected sequence number in midQ entry BB */

	if((cifs_pdu == NULL) || (server == NULL))
		return -EINVAL;

	if((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0) 
		return rc;

	spin_lock(&GlobalMid_Lock);
	cifs_pdu->Signature.Sequence.SequenceNumber = cpu_to_le32(server->sequence_number);
	cifs_pdu->Signature.Sequence.Reserved = 0;
	
	*pexpected_response_sequence_number = server->sequence_number++;
	server->sequence_number++;
	spin_unlock(&GlobalMid_Lock);

	rc = cifs_calculate_signature(cifs_pdu, server->mac_signing_key,smb_signature);
	if(rc)
		memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
	else
		memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);

	return rc;
}

static int cifs_calc_signature2(const struct kvec * iov, int n_vec,
				const char * key, char * signature)
{
        struct  MD5Context context;

        if((iov == NULL) || (signature == NULL))
                return -EINVAL;

        MD5Init(&context);
        MD5Update(&context,key,CIFS_SESSION_KEY_SIZE+16);

/*        MD5Update(&context,cifs_pdu->Protocol,cifs_pdu->smb_buf_length); */ /* BB FIXME BB */

        MD5Final(signature,&context);

	return -EOPNOTSUPP;
/*        return 0; */
}


int cifs_sign_smb2(struct kvec * iov, int n_vec, struct TCP_Server_Info *server,
		   __u32 * pexpected_response_sequence_number)
{
	int rc = 0;
	char smb_signature[20];
	struct smb_hdr * cifs_pdu = iov[0].iov_base;

	if((cifs_pdu == NULL) || (server == NULL))
		return -EINVAL;

	if((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0)
		return rc;

        spin_lock(&GlobalMid_Lock);
        cifs_pdu->Signature.Sequence.SequenceNumber = 
				cpu_to_le32(server->sequence_number);
        cifs_pdu->Signature.Sequence.Reserved = 0;

        *pexpected_response_sequence_number = server->sequence_number++;
        server->sequence_number++;
        spin_unlock(&GlobalMid_Lock);

        rc = cifs_calc_signature2(iov, n_vec, server->mac_signing_key,
				      smb_signature);
        if(rc)
                memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
        else
                memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);

        return rc;

}

int cifs_verify_signature(struct smb_hdr * cifs_pdu, const char * mac_key,
	__u32 expected_sequence_number)
{
	unsigned int rc;
	char server_response_sig[8];
	char what_we_think_sig_should_be[20];

	if((cifs_pdu == NULL) || (mac_key == NULL))
		return -EINVAL;

	if (cifs_pdu->Command == SMB_COM_NEGOTIATE)
		return 0;

	if (cifs_pdu->Command == SMB_COM_LOCKING_ANDX) {
		struct smb_com_lock_req * pSMB = (struct smb_com_lock_req *)cifs_pdu;
	    if(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE)
			return 0;
	}

	/* BB what if signatures are supposed to be on for session but server does not
		send one? BB */
	
	/* Do not need to verify session setups with signature "BSRSPYL "  */
	if(memcmp(cifs_pdu->Signature.SecuritySignature,"BSRSPYL ",8)==0)
		cFYI(1,("dummy signature received for smb command 0x%x",cifs_pdu->Command));

	/* save off the origiginal signature so we can modify the smb and check
		its signature against what the server sent */
	memcpy(server_response_sig,cifs_pdu->Signature.SecuritySignature,8);

	cifs_pdu->Signature.Sequence.SequenceNumber = cpu_to_le32(expected_sequence_number);
	cifs_pdu->Signature.Sequence.Reserved = 0;

	rc = cifs_calculate_signature(cifs_pdu, mac_key,
		what_we_think_sig_should_be);

	if(rc)
		return rc;

	
/*	cifs_dump_mem("what we think it should be: ",what_we_think_sig_should_be,16); */

	if(memcmp(server_response_sig, what_we_think_sig_should_be, 8))
		return -EACCES;
	else
		return 0;

}

/* We fill in key by putting in 40 byte array which was allocated by caller */
int cifs_calculate_mac_key(char * key, const char * rn, const char * password)
{
	char temp_key[16];
	if ((key == NULL) || (rn == NULL))
		return -EINVAL;

	E_md4hash(password, temp_key);
	mdfour(key,temp_key,16);
	memcpy(key+16,rn, CIFS_SESSION_KEY_SIZE);
	return 0;
}

int CalcNTLMv2_partial_mac_key(struct cifsSesInfo * ses, struct nls_table * nls_info)
{
	char temp_hash[16];
	struct HMACMD5Context ctx;
	char * ucase_buf;
	__le16 * unicode_buf;
	unsigned int i,user_name_len,dom_name_len;

	if(ses == NULL)
		return -EINVAL;

	E_md4hash(ses->password, temp_hash);

	hmac_md5_init_limK_to_64(temp_hash, 16, &ctx);
	user_name_len = strlen(ses->userName);
	if(user_name_len > MAX_USERNAME_SIZE)
		return -EINVAL;
	dom_name_len = strlen(ses->domainName);
	if(dom_name_len > MAX_USERNAME_SIZE)
		return -EINVAL;
  
	ucase_buf = kmalloc((MAX_USERNAME_SIZE+1), GFP_KERNEL);
	if(ucase_buf == NULL)
		return -ENOMEM;
	unicode_buf = kmalloc((MAX_USERNAME_SIZE+1)*4, GFP_KERNEL);
	if(unicode_buf == NULL) {
		kfree(ucase_buf);
		return -ENOMEM;
	}
   
	for(i=0;i<user_name_len;i++)
		ucase_buf[i] = nls_info->charset2upper[(int)ses->userName[i]];
	ucase_buf[i] = 0;
	user_name_len = cifs_strtoUCS(unicode_buf, ucase_buf, MAX_USERNAME_SIZE*2, nls_info);
	unicode_buf[user_name_len] = 0;
	user_name_len++;

	for(i=0;i<dom_name_len;i++)
		ucase_buf[i] = nls_info->charset2upper[(int)ses->domainName[i]];
	ucase_buf[i] = 0;
	dom_name_len = cifs_strtoUCS(unicode_buf+user_name_len, ucase_buf, MAX_USERNAME_SIZE*2, nls_info);

	unicode_buf[user_name_len + dom_name_len] = 0;
	hmac_md5_update((const unsigned char *) unicode_buf,
		(user_name_len+dom_name_len)*2,&ctx);

	hmac_md5_final(ses->server->mac_signing_key,&ctx);
	kfree(ucase_buf);
	kfree(unicode_buf);
	return 0;
}
void CalcNTLMv2_response(const struct cifsSesInfo * ses,char * v2_session_response)
{
	struct HMACMD5Context context;
	memcpy(v2_session_response + 8, ses->server->cryptKey,8);
	/* gen_blob(v2_session_response + 16); */
	hmac_md5_init_limK_to_64(ses->server->mac_signing_key, 16, &context);

	hmac_md5_update(ses->server->cryptKey,8,&context);
/*	hmac_md5_update(v2_session_response+16)client thing,8,&context); */ /* BB fix */

	hmac_md5_final(v2_session_response,&context);
}