tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * fs/cifs/cifs_spnego.c -- SPNEGO upcall management for CIFS
3 *
4 * Copyright (c) 2007 Red Hat, Inc.
5 * Author(s): Jeff Layton (jlayton@redhat.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/list.h>
23#include <linux/string.h>
24#include <keys/user-type.h>
25#include <linux/key-type.h>
26#include "cifsglob.h"
27#include "cifs_spnego.h"
28#include "cifs_debug.h"
29
30/* create a new cifs key */
31static int
32cifs_spnego_key_instantiate(struct key *key, const void *data, size_t datalen)
33{
34 char *payload;
35 int ret;
36
37 ret = -ENOMEM;
38 payload = kmalloc(datalen, GFP_KERNEL);
39 if (!payload)
40 goto error;
41
42 /* attach the data */
43 memcpy(payload, data, datalen);
44 key->payload.data = payload;
45 ret = 0;
46
47error:
48 return ret;
49}
50
51static void
52cifs_spnego_key_destroy(struct key *key)
53{
54 kfree(key->payload.data);
55}
56
57
58/*
59 * keytype for CIFS spnego keys
60 */
61struct key_type cifs_spnego_key_type = {
62 .name = "cifs.spnego",
63 .instantiate = cifs_spnego_key_instantiate,
64 .match = user_match,
65 .destroy = cifs_spnego_key_destroy,
66 .describe = user_describe,
67};
68
69/* length of longest version string e.g. strlen("ver=0xFF") */
70#define MAX_VER_STR_LEN 8
71
72/* length of longest security mechanism name, eg in future could have
73 * strlen(";sec=ntlmsspi") */
74#define MAX_MECH_STR_LEN 13
75
76/* max possible addr len eg FEDC:BA98:7654:3210:FEDC:BA98:7654:3210/128 */
77#define MAX_IPV6_ADDR_LEN 43
78
79/* strlen of "host=" */
80#define HOST_KEY_LEN 5
81
82/* strlen of ";ip4=" or ";ip6=" */
83#define IP_KEY_LEN 5
84
85/* strlen of ";uid=0x" */
86#define UID_KEY_LEN 7
87
88/* strlen of ";user=" */
89#define USER_KEY_LEN 6
90
91/* get a key struct with a SPNEGO security blob, suitable for session setup */
92struct key *
93cifs_get_spnego_key(struct cifsSesInfo *sesInfo)
94{
95 struct TCP_Server_Info *server = sesInfo->server;
96 char *description, *dp;
97 size_t desc_len;
98 struct key *spnego_key;
99 const char *hostname = server->hostname;
100
101 /* length of fields (with semicolons): ver=0xyz ip4=ipaddress
102 host=hostname sec=mechanism uid=0xFF user=username */
103 desc_len = MAX_VER_STR_LEN +
104 HOST_KEY_LEN + strlen(hostname) +
105 IP_KEY_LEN + MAX_IPV6_ADDR_LEN +
106 MAX_MECH_STR_LEN +
107 UID_KEY_LEN + (sizeof(uid_t) * 2) +
108 USER_KEY_LEN + strlen(sesInfo->userName) + 1;
109
110 spnego_key = ERR_PTR(-ENOMEM);
111 description = kzalloc(desc_len, GFP_KERNEL);
112 if (description == NULL)
113 goto out;
114
115 dp = description;
116 /* start with version and hostname portion of UNC string */
117 spnego_key = ERR_PTR(-EINVAL);
118 sprintf(dp, "ver=0x%x;host=%s;", CIFS_SPNEGO_UPCALL_VERSION,
119 hostname);
120 dp = description + strlen(description);
121
122 /* add the server address */
123 if (server->addr.sockAddr.sin_family == AF_INET)
124 sprintf(dp, "ip4=%pI4", &server->addr.sockAddr.sin_addr);
125 else if (server->addr.sockAddr.sin_family == AF_INET6)
126 sprintf(dp, "ip6=%pi6", &server->addr.sockAddr6.sin6_addr);
127 else
128 goto out;
129
130 dp = description + strlen(description);
131
132 /* for now, only sec=krb5 and sec=mskrb5 are valid */
133 if (server->secType == Kerberos)
134 sprintf(dp, ";sec=krb5");
135 else if (server->secType == MSKerberos)
136 sprintf(dp, ";sec=mskrb5");
137 else
138 goto out;
139
140 dp = description + strlen(description);
141 sprintf(dp, ";uid=0x%x", sesInfo->linux_uid);
142
143 dp = description + strlen(description);
144 sprintf(dp, ";user=%s", sesInfo->userName);
145
146 cFYI(1, ("key description = %s", description));
147 spnego_key = request_key(&cifs_spnego_key_type, description, "");
148
149#ifdef CONFIG_CIFS_DEBUG2
150 if (cifsFYI && !IS_ERR(spnego_key)) {
151 struct cifs_spnego_msg *msg = spnego_key->payload.data;
152 cifs_dump_mem("SPNEGO reply blob:", msg->data, min(1024U,
153 msg->secblob_len + msg->sesskey_len));
154 }
155#endif /* CONFIG_CIFS_DEBUG2 */
156
157out:
158 kfree(description);
159 return spnego_key;
160}