summaryrefslogtreecommitdiffstats
path: root/fs/cifs/cifs_spnego.c
blob: 117ef4bba68ec6c52f03164baaad5361e7937d69 (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
/*
 *   fs/cifs/cifs_spnego.c -- SPNEGO upcall management for CIFS
 *
 *   Copyright (c) 2007 Red Hat, Inc.
 *   Author(s): Jeff Layton (jlayton@redhat.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/list.h>
#include <linux/string.h>
#include <keys/user-type.h>
#include <linux/key-type.h>
#include "cifsglob.h"
#include "cifs_spnego.h"
#include "cifs_debug.h"

/* create a new cifs key */
static int
cifs_spnego_key_instantiate(struct key *key, const void *data, size_t datalen)
{
	char *payload;
	int ret;

	ret = -ENOMEM;
	payload = kmalloc(datalen, GFP_KERNEL);
	if (!payload)
		goto error;

	/* attach the data */
	memcpy(payload, data, datalen);
	rcu_assign_pointer(key->payload.data, payload);
	ret = 0;

error:
	return ret;
}

static void
cifs_spnego_key_destroy(struct key *key)
{
	kfree(key->payload.data);
}


/*
 * keytype for CIFS spnego keys
 */
struct key_type cifs_spnego_key_type = {
	.name		= "cifs.spnego",
	.instantiate	= cifs_spnego_key_instantiate,
	.match		= user_match,
	.destroy	= cifs_spnego_key_destroy,
	.describe	= user_describe,
};

#define MAX_VER_STR_LEN   8 /* length of longest version string e.g.
				strlen("ver=0xFF") */
#define MAX_MECH_STR_LEN 13 /* length of longest security mechanism name, eg
			       in future could have strlen(";sec=ntlmsspi") */
#define MAX_IPV6_ADDR_LEN 42 /* eg FEDC:BA98:7654:3210:FEDC:BA98:7654:3210/60 */
/* get a key struct with a SPNEGO security blob, suitable for session setup */
struct key *
cifs_get_spnego_key(struct cifsSesInfo *sesInfo)
{
	struct TCP_Server_Info *server = sesInfo->server;
	char *description, *dp;
	size_t desc_len;
	struct key *spnego_key;
	const char *hostname = server->hostname;

	/* length of fields (with semicolons): ver=0xyz ip4=ipaddress
	   host=hostname sec=mechanism uid=0xFF user=username */
	desc_len = MAX_VER_STR_LEN +
		   6 /* len of "host=" */ + strlen(hostname) +
		   5 /* len of ";ipv4=" */ + MAX_IPV6_ADDR_LEN +
		   MAX_MECH_STR_LEN +
		   7 /* len of ";uid=0x" */ + (sizeof(uid_t) * 2) +
		   6 /* len of ";user=" */ + strlen(sesInfo->userName) + 1;

	spnego_key = ERR_PTR(-ENOMEM);
	description = kzalloc(desc_len, GFP_KERNEL);
	if (description == NULL)
		goto out;

	dp = description;
	/* start with version and hostname portion of UNC string */
	spnego_key = ERR_PTR(-EINVAL);
	sprintf(dp, "ver=0x%x;host=%s;", CIFS_SPNEGO_UPCALL_VERSION,
		hostname);
	dp = description + strlen(description);

	/* add the server address */
	if (server->addr.sockAddr.sin_family == AF_INET)
		sprintf(dp, "ip4=" NIPQUAD_FMT,
			NIPQUAD(server->addr.sockAddr.sin_addr));
	else if (server->addr.sockAddr.sin_family == AF_INET6)
		sprintf(dp, "ip6=" NIP6_SEQFMT,
			NIP6(server->addr.sockAddr6.sin6_addr));
	else
		goto out;

	dp = description + strlen(description);

	/* for now, only sec=krb5 and sec=mskrb5 are valid */
	if (server->secType == Kerberos)
		sprintf(dp, ";sec=krb5");
	else if (server->secType == MSKerberos)
		sprintf(dp, ";sec=mskrb5");
	else
		goto out;

	dp = description + strlen(description);
	sprintf(dp, ";uid=0x%x", sesInfo->linux_uid);

	dp = description + strlen(description);
	sprintf(dp, ";user=%s", sesInfo->userName);

	cFYI(1, ("key description = %s", description));
	spnego_key = request_key(&cifs_spnego_key_type, description, "");

#ifdef CONFIG_CIFS_DEBUG2
	if (cifsFYI && !IS_ERR(spnego_key)) {
		struct cifs_spnego_msg *msg = spnego_key->payload.data;
		cifs_dump_mem("SPNEGO reply blob:", msg->data, min(1024U,
				msg->secblob_len + msg->sesskey_len));
	}
#endif /* CONFIG_CIFS_DEBUG2 */

out:
	kfree(description);
	return spnego_key;
}
OpenPOWER on IntegriCloud