]>
Commit | Line | Data |
---|---|---|
929be906 | 1 | // SPDX-License-Identifier: LGPL-2.1 |
f1d662a7 | 2 | /* |
099dd788 | 3 | * SPNEGO upcall management for CIFS |
f1d662a7 SF |
4 | * |
5 | * Copyright (c) 2007 Red Hat, Inc. | |
6 | * Author(s): Jeff Layton (jlayton@redhat.com) | |
7 | * | |
f1d662a7 SF |
8 | */ |
9 | ||
10 | #include <linux/list.h> | |
5a0e3ad6 | 11 | #include <linux/slab.h> |
f1d662a7 SF |
12 | #include <linux/string.h> |
13 | #include <keys/user-type.h> | |
14 | #include <linux/key-type.h> | |
b74cb9a8 | 15 | #include <linux/keyctl.h> |
50b64e3b | 16 | #include <linux/inet.h> |
f1d662a7 SF |
17 | #include "cifsglob.h" |
18 | #include "cifs_spnego.h" | |
19 | #include "cifs_debug.h" | |
b74cb9a8 SP |
20 | #include "cifsproto.h" |
21 | static const struct cred *spnego_cred; | |
f1d662a7 SF |
22 | |
23 | /* create a new cifs key */ | |
24 | static int | |
cf7f601c | 25 | cifs_spnego_key_instantiate(struct key *key, struct key_preparsed_payload *prep) |
f1d662a7 SF |
26 | { |
27 | char *payload; | |
28 | int ret; | |
29 | ||
30 | ret = -ENOMEM; | |
f7f7c185 | 31 | payload = kmemdup(prep->data, prep->datalen, GFP_KERNEL); |
f1d662a7 SF |
32 | if (!payload) |
33 | goto error; | |
34 | ||
35 | /* attach the data */ | |
146aa8b1 | 36 | key->payload.data[0] = payload; |
f1d662a7 SF |
37 | ret = 0; |
38 | ||
39 | error: | |
40 | return ret; | |
41 | } | |
42 | ||
43 | static void | |
44 | cifs_spnego_key_destroy(struct key *key) | |
45 | { | |
146aa8b1 | 46 | kfree(key->payload.data[0]); |
f1d662a7 SF |
47 | } |
48 | ||
49 | ||
50 | /* | |
51 | * keytype for CIFS spnego keys | |
52 | */ | |
53 | struct key_type cifs_spnego_key_type = { | |
54 | .name = "cifs.spnego", | |
55 | .instantiate = cifs_spnego_key_instantiate, | |
f1d662a7 SF |
56 | .destroy = cifs_spnego_key_destroy, |
57 | .describe = user_describe, | |
58 | }; | |
59 | ||
7c9c3760 SF |
60 | /* length of longest version string e.g. strlen("ver=0xFF") */ |
61 | #define MAX_VER_STR_LEN 8 | |
62 | ||
63 | /* length of longest security mechanism name, eg in future could have | |
64 | * strlen(";sec=ntlmsspi") */ | |
65 | #define MAX_MECH_STR_LEN 13 | |
66 | ||
7c9c3760 SF |
67 | /* strlen of "host=" */ |
68 | #define HOST_KEY_LEN 5 | |
69 | ||
70 | /* strlen of ";ip4=" or ";ip6=" */ | |
71 | #define IP_KEY_LEN 5 | |
72 | ||
73 | /* strlen of ";uid=0x" */ | |
74 | #define UID_KEY_LEN 7 | |
75 | ||
ba5dadbf JL |
76 | /* strlen of ";creduid=0x" */ |
77 | #define CREDUID_KEY_LEN 11 | |
78 | ||
7c9c3760 SF |
79 | /* strlen of ";user=" */ |
80 | #define USER_KEY_LEN 6 | |
81 | ||
c4c1bff6 JL |
82 | /* strlen of ";pid=0x" */ |
83 | #define PID_KEY_LEN 7 | |
84 | ||
f1d662a7 SF |
85 | /* get a key struct with a SPNEGO security blob, suitable for session setup */ |
86 | struct key * | |
96daf2b0 | 87 | cifs_get_spnego_key(struct cifs_ses *sesInfo) |
f1d662a7 | 88 | { |
f6a6bf7c | 89 | struct TCP_Server_Info *server = cifs_ses_server(sesInfo); |
a9f1b85e PS |
90 | struct sockaddr_in *sa = (struct sockaddr_in *) &server->dstaddr; |
91 | struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *) &server->dstaddr; | |
f1d662a7 SF |
92 | char *description, *dp; |
93 | size_t desc_len; | |
94 | struct key *spnego_key; | |
d6c2e4d0 | 95 | const char *hostname = server->hostname; |
b74cb9a8 | 96 | const struct cred *saved_cred; |
f1d662a7 | 97 | |
66b8bd3c JL |
98 | /* length of fields (with semicolons): ver=0xyz ip4=ipaddress |
99 | host=hostname sec=mechanism uid=0xFF user=username */ | |
100 | desc_len = MAX_VER_STR_LEN + | |
7c9c3760 | 101 | HOST_KEY_LEN + strlen(hostname) + |
50b64e3b | 102 | IP_KEY_LEN + INET6_ADDRSTRLEN + |
66b8bd3c | 103 | MAX_MECH_STR_LEN + |
7c9c3760 | 104 | UID_KEY_LEN + (sizeof(uid_t) * 2) + |
ba5dadbf | 105 | CREDUID_KEY_LEN + (sizeof(uid_t) * 2) + |
c4c1bff6 | 106 | PID_KEY_LEN + (sizeof(pid_t) * 2) + 1; |
66b8bd3c | 107 | |
04febabc JL |
108 | if (sesInfo->user_name) |
109 | desc_len += USER_KEY_LEN + strlen(sesInfo->user_name); | |
110 | ||
f1d662a7 SF |
111 | spnego_key = ERR_PTR(-ENOMEM); |
112 | description = kzalloc(desc_len, GFP_KERNEL); | |
113 | if (description == NULL) | |
114 | goto out; | |
115 | ||
116 | dp = description; | |
117 | /* start with version and hostname portion of UNC string */ | |
118 | spnego_key = ERR_PTR(-EINVAL); | |
68bf728a | 119 | sprintf(dp, "ver=0x%x;host=%s;", CIFS_SPNEGO_UPCALL_VERSION, |
f1d662a7 SF |
120 | hostname); |
121 | dp = description + strlen(description); | |
122 | ||
123 | /* add the server address */ | |
a9f1b85e PS |
124 | if (server->dstaddr.ss_family == AF_INET) |
125 | sprintf(dp, "ip4=%pI4", &sa->sin_addr); | |
126 | else if (server->dstaddr.ss_family == AF_INET6) | |
127 | sprintf(dp, "ip6=%pI6", &sa6->sin6_addr); | |
f1d662a7 SF |
128 | else |
129 | goto out; | |
130 | ||
131 | dp = description + strlen(description); | |
132 | ||
c16fefa5 | 133 | /* for now, only sec=krb5 and sec=mskrb5 are valid */ |
26efa0ba | 134 | if (server->sec_kerberos) |
f1d662a7 | 135 | sprintf(dp, ";sec=krb5"); |
26efa0ba | 136 | else if (server->sec_mskerberos) |
c16fefa5 | 137 | sprintf(dp, ";sec=mskrb5"); |
926674de SF |
138 | else { |
139 | cifs_dbg(VFS, "unknown or missing server auth type, use krb5\n"); | |
140 | sprintf(dp, ";sec=krb5"); | |
141 | } | |
f1d662a7 | 142 | |
9eae8a89 | 143 | dp = description + strlen(description); |
64ed39dd EB |
144 | sprintf(dp, ";uid=0x%x", |
145 | from_kuid_munged(&init_user_ns, sesInfo->linux_uid)); | |
9eae8a89 | 146 | |
3e4b3e1f | 147 | dp = description + strlen(description); |
64ed39dd EB |
148 | sprintf(dp, ";creduid=0x%x", |
149 | from_kuid_munged(&init_user_ns, sesInfo->cred_uid)); | |
3e4b3e1f | 150 | |
04febabc JL |
151 | if (sesInfo->user_name) { |
152 | dp = description + strlen(description); | |
153 | sprintf(dp, ";user=%s", sesInfo->user_name); | |
154 | } | |
e4058245 | 155 | |
c4c1bff6 JL |
156 | dp = description + strlen(description); |
157 | sprintf(dp, ";pid=0x%x", current->pid); | |
158 | ||
f96637be | 159 | cifs_dbg(FYI, "key description = %s\n", description); |
b74cb9a8 | 160 | saved_cred = override_creds(spnego_cred); |
028db3e2 | 161 | spnego_key = request_key(&cifs_spnego_key_type, description, ""); |
b74cb9a8 | 162 | revert_creds(saved_cred); |
f1d662a7 | 163 | |
05b3de63 | 164 | #ifdef CONFIG_CIFS_DEBUG2 |
f1d662a7 | 165 | if (cifsFYI && !IS_ERR(spnego_key)) { |
146aa8b1 | 166 | struct cifs_spnego_msg *msg = spnego_key->payload.data[0]; |
ead03e30 | 167 | cifs_dump_mem("SPNEGO reply blob:", msg->data, min(1024U, |
05b3de63 | 168 | msg->secblob_len + msg->sesskey_len)); |
f1d662a7 | 169 | } |
05b3de63 | 170 | #endif /* CONFIG_CIFS_DEBUG2 */ |
f1d662a7 SF |
171 | |
172 | out: | |
173 | kfree(description); | |
174 | return spnego_key; | |
175 | } | |
b74cb9a8 SP |
176 | |
177 | int | |
178 | init_cifs_spnego(void) | |
179 | { | |
180 | struct cred *cred; | |
181 | struct key *keyring; | |
182 | int ret; | |
183 | ||
184 | cifs_dbg(FYI, "Registering the %s key type\n", | |
185 | cifs_spnego_key_type.name); | |
186 | ||
187 | /* | |
188 | * Create an override credential set with special thread keyring for | |
189 | * spnego upcalls. | |
190 | */ | |
191 | ||
192 | cred = prepare_kernel_cred(NULL); | |
193 | if (!cred) | |
194 | return -ENOMEM; | |
195 | ||
196 | keyring = keyring_alloc(".cifs_spnego", | |
197 | GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred, | |
028db3e2 LT |
198 | (KEY_POS_ALL & ~KEY_POS_SETATTR) | |
199 | KEY_USR_VIEW | KEY_USR_READ, | |
b74cb9a8 SP |
200 | KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL); |
201 | if (IS_ERR(keyring)) { | |
202 | ret = PTR_ERR(keyring); | |
203 | goto failed_put_cred; | |
204 | } | |
205 | ||
206 | ret = register_key_type(&cifs_spnego_key_type); | |
207 | if (ret < 0) | |
208 | goto failed_put_key; | |
209 | ||
210 | /* | |
211 | * instruct request_key() to use this special keyring as a cache for | |
212 | * the results it looks up | |
213 | */ | |
214 | set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags); | |
215 | cred->thread_keyring = keyring; | |
216 | cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING; | |
217 | spnego_cred = cred; | |
218 | ||
219 | cifs_dbg(FYI, "cifs spnego keyring: %d\n", key_serial(keyring)); | |
220 | return 0; | |
221 | ||
222 | failed_put_key: | |
223 | key_put(keyring); | |
224 | failed_put_cred: | |
225 | put_cred(cred); | |
226 | return ret; | |
227 | } | |
228 | ||
229 | void | |
230 | exit_cifs_spnego(void) | |
231 | { | |
232 | key_revoke(spnego_cred->thread_keyring); | |
233 | unregister_key_type(&cifs_spnego_key_type); | |
234 | put_cred(spnego_cred); | |
235 | cifs_dbg(FYI, "Unregistered %s key type\n", cifs_spnego_key_type.name); | |
236 | } |