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f1d662a7 SF |
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 ([email protected]) | |
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> | |
5a0e3ad6 | 23 | #include <linux/slab.h> |
f1d662a7 SF |
24 | #include <linux/string.h> |
25 | #include <keys/user-type.h> | |
26 | #include <linux/key-type.h> | |
b74cb9a8 | 27 | #include <linux/keyctl.h> |
50b64e3b | 28 | #include <linux/inet.h> |
f1d662a7 SF |
29 | #include "cifsglob.h" |
30 | #include "cifs_spnego.h" | |
31 | #include "cifs_debug.h" | |
b74cb9a8 SP |
32 | #include "cifsproto.h" |
33 | static const struct cred *spnego_cred; | |
f1d662a7 SF |
34 | |
35 | /* create a new cifs key */ | |
36 | static int | |
cf7f601c | 37 | cifs_spnego_key_instantiate(struct key *key, struct key_preparsed_payload *prep) |
f1d662a7 SF |
38 | { |
39 | char *payload; | |
40 | int ret; | |
41 | ||
42 | ret = -ENOMEM; | |
f7f7c185 | 43 | payload = kmemdup(prep->data, prep->datalen, GFP_KERNEL); |
f1d662a7 SF |
44 | if (!payload) |
45 | goto error; | |
46 | ||
47 | /* attach the data */ | |
146aa8b1 | 48 | key->payload.data[0] = payload; |
f1d662a7 SF |
49 | ret = 0; |
50 | ||
51 | error: | |
52 | return ret; | |
53 | } | |
54 | ||
55 | static void | |
56 | cifs_spnego_key_destroy(struct key *key) | |
57 | { | |
146aa8b1 | 58 | kfree(key->payload.data[0]); |
f1d662a7 SF |
59 | } |
60 | ||
61 | ||
62 | /* | |
63 | * keytype for CIFS spnego keys | |
64 | */ | |
65 | struct key_type cifs_spnego_key_type = { | |
66 | .name = "cifs.spnego", | |
67 | .instantiate = cifs_spnego_key_instantiate, | |
f1d662a7 SF |
68 | .destroy = cifs_spnego_key_destroy, |
69 | .describe = user_describe, | |
70 | }; | |
71 | ||
7c9c3760 SF |
72 | /* length of longest version string e.g. strlen("ver=0xFF") */ |
73 | #define MAX_VER_STR_LEN 8 | |
74 | ||
75 | /* length of longest security mechanism name, eg in future could have | |
76 | * strlen(";sec=ntlmsspi") */ | |
77 | #define MAX_MECH_STR_LEN 13 | |
78 | ||
7c9c3760 SF |
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 | ||
ba5dadbf JL |
88 | /* strlen of ";creduid=0x" */ |
89 | #define CREDUID_KEY_LEN 11 | |
90 | ||
7c9c3760 SF |
91 | /* strlen of ";user=" */ |
92 | #define USER_KEY_LEN 6 | |
93 | ||
c4c1bff6 JL |
94 | /* strlen of ";pid=0x" */ |
95 | #define PID_KEY_LEN 7 | |
96 | ||
f1d662a7 SF |
97 | /* get a key struct with a SPNEGO security blob, suitable for session setup */ |
98 | struct key * | |
96daf2b0 | 99 | cifs_get_spnego_key(struct cifs_ses *sesInfo) |
f1d662a7 SF |
100 | { |
101 | struct TCP_Server_Info *server = sesInfo->server; | |
a9f1b85e PS |
102 | struct sockaddr_in *sa = (struct sockaddr_in *) &server->dstaddr; |
103 | struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *) &server->dstaddr; | |
f1d662a7 SF |
104 | char *description, *dp; |
105 | size_t desc_len; | |
106 | struct key *spnego_key; | |
d6c2e4d0 | 107 | const char *hostname = server->hostname; |
b74cb9a8 | 108 | const struct cred *saved_cred; |
f1d662a7 | 109 | |
66b8bd3c JL |
110 | /* length of fields (with semicolons): ver=0xyz ip4=ipaddress |
111 | host=hostname sec=mechanism uid=0xFF user=username */ | |
112 | desc_len = MAX_VER_STR_LEN + | |
7c9c3760 | 113 | HOST_KEY_LEN + strlen(hostname) + |
50b64e3b | 114 | IP_KEY_LEN + INET6_ADDRSTRLEN + |
66b8bd3c | 115 | MAX_MECH_STR_LEN + |
7c9c3760 | 116 | UID_KEY_LEN + (sizeof(uid_t) * 2) + |
ba5dadbf | 117 | CREDUID_KEY_LEN + (sizeof(uid_t) * 2) + |
c4c1bff6 | 118 | PID_KEY_LEN + (sizeof(pid_t) * 2) + 1; |
66b8bd3c | 119 | |
04febabc JL |
120 | if (sesInfo->user_name) |
121 | desc_len += USER_KEY_LEN + strlen(sesInfo->user_name); | |
122 | ||
f1d662a7 SF |
123 | spnego_key = ERR_PTR(-ENOMEM); |
124 | description = kzalloc(desc_len, GFP_KERNEL); | |
125 | if (description == NULL) | |
126 | goto out; | |
127 | ||
128 | dp = description; | |
129 | /* start with version and hostname portion of UNC string */ | |
130 | spnego_key = ERR_PTR(-EINVAL); | |
68bf728a | 131 | sprintf(dp, "ver=0x%x;host=%s;", CIFS_SPNEGO_UPCALL_VERSION, |
f1d662a7 SF |
132 | hostname); |
133 | dp = description + strlen(description); | |
134 | ||
135 | /* add the server address */ | |
a9f1b85e PS |
136 | if (server->dstaddr.ss_family == AF_INET) |
137 | sprintf(dp, "ip4=%pI4", &sa->sin_addr); | |
138 | else if (server->dstaddr.ss_family == AF_INET6) | |
139 | sprintf(dp, "ip6=%pI6", &sa6->sin6_addr); | |
f1d662a7 SF |
140 | else |
141 | goto out; | |
142 | ||
143 | dp = description + strlen(description); | |
144 | ||
c16fefa5 | 145 | /* for now, only sec=krb5 and sec=mskrb5 are valid */ |
26efa0ba | 146 | if (server->sec_kerberos) |
f1d662a7 | 147 | sprintf(dp, ";sec=krb5"); |
26efa0ba | 148 | else if (server->sec_mskerberos) |
c16fefa5 | 149 | sprintf(dp, ";sec=mskrb5"); |
f1d662a7 SF |
150 | else |
151 | goto out; | |
152 | ||
9eae8a89 | 153 | dp = description + strlen(description); |
64ed39dd EB |
154 | sprintf(dp, ";uid=0x%x", |
155 | from_kuid_munged(&init_user_ns, sesInfo->linux_uid)); | |
9eae8a89 | 156 | |
3e4b3e1f | 157 | dp = description + strlen(description); |
64ed39dd EB |
158 | sprintf(dp, ";creduid=0x%x", |
159 | from_kuid_munged(&init_user_ns, sesInfo->cred_uid)); | |
3e4b3e1f | 160 | |
04febabc JL |
161 | if (sesInfo->user_name) { |
162 | dp = description + strlen(description); | |
163 | sprintf(dp, ";user=%s", sesInfo->user_name); | |
164 | } | |
e4058245 | 165 | |
c4c1bff6 JL |
166 | dp = description + strlen(description); |
167 | sprintf(dp, ";pid=0x%x", current->pid); | |
168 | ||
f96637be | 169 | cifs_dbg(FYI, "key description = %s\n", description); |
b74cb9a8 | 170 | saved_cred = override_creds(spnego_cred); |
f1d662a7 | 171 | spnego_key = request_key(&cifs_spnego_key_type, description, ""); |
b74cb9a8 | 172 | revert_creds(saved_cred); |
f1d662a7 | 173 | |
05b3de63 | 174 | #ifdef CONFIG_CIFS_DEBUG2 |
f1d662a7 | 175 | if (cifsFYI && !IS_ERR(spnego_key)) { |
146aa8b1 | 176 | struct cifs_spnego_msg *msg = spnego_key->payload.data[0]; |
ead03e30 | 177 | cifs_dump_mem("SPNEGO reply blob:", msg->data, min(1024U, |
05b3de63 | 178 | msg->secblob_len + msg->sesskey_len)); |
f1d662a7 | 179 | } |
05b3de63 | 180 | #endif /* CONFIG_CIFS_DEBUG2 */ |
f1d662a7 SF |
181 | |
182 | out: | |
183 | kfree(description); | |
184 | return spnego_key; | |
185 | } | |
b74cb9a8 SP |
186 | |
187 | int | |
188 | init_cifs_spnego(void) | |
189 | { | |
190 | struct cred *cred; | |
191 | struct key *keyring; | |
192 | int ret; | |
193 | ||
194 | cifs_dbg(FYI, "Registering the %s key type\n", | |
195 | cifs_spnego_key_type.name); | |
196 | ||
197 | /* | |
198 | * Create an override credential set with special thread keyring for | |
199 | * spnego upcalls. | |
200 | */ | |
201 | ||
202 | cred = prepare_kernel_cred(NULL); | |
203 | if (!cred) | |
204 | return -ENOMEM; | |
205 | ||
206 | keyring = keyring_alloc(".cifs_spnego", | |
207 | GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred, | |
208 | (KEY_POS_ALL & ~KEY_POS_SETATTR) | | |
209 | KEY_USR_VIEW | KEY_USR_READ, | |
210 | KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL); | |
211 | if (IS_ERR(keyring)) { | |
212 | ret = PTR_ERR(keyring); | |
213 | goto failed_put_cred; | |
214 | } | |
215 | ||
216 | ret = register_key_type(&cifs_spnego_key_type); | |
217 | if (ret < 0) | |
218 | goto failed_put_key; | |
219 | ||
220 | /* | |
221 | * instruct request_key() to use this special keyring as a cache for | |
222 | * the results it looks up | |
223 | */ | |
224 | set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags); | |
225 | cred->thread_keyring = keyring; | |
226 | cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING; | |
227 | spnego_cred = cred; | |
228 | ||
229 | cifs_dbg(FYI, "cifs spnego keyring: %d\n", key_serial(keyring)); | |
230 | return 0; | |
231 | ||
232 | failed_put_key: | |
233 | key_put(keyring); | |
234 | failed_put_cred: | |
235 | put_cred(cred); | |
236 | return ret; | |
237 | } | |
238 | ||
239 | void | |
240 | exit_cifs_spnego(void) | |
241 | { | |
242 | key_revoke(spnego_cred->thread_keyring); | |
243 | unregister_key_type(&cifs_spnego_key_type); | |
244 | put_cred(spnego_cred); | |
245 | cifs_dbg(FYI, "Unregistered %s key type\n", cifs_spnego_key_type.name); | |
246 | } |