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10#include <linux/sched.h>
11#include <linux/err.h>
12#include <linux/seq_file.h>
13#include <linux/slab.h>
14#include <linux/uaccess.h>
15#include "internal.h"
16#include <keys/request_key_auth-type.h>
17
18static int request_key_auth_preparse(struct key_preparsed_payload *);
19static void request_key_auth_free_preparse(struct key_preparsed_payload *);
20static int request_key_auth_instantiate(struct key *,
21 struct key_preparsed_payload *);
22static void request_key_auth_describe(const struct key *, struct seq_file *);
23static void request_key_auth_revoke(struct key *);
24static void request_key_auth_destroy(struct key *);
25static long request_key_auth_read(const struct key *, char __user *, size_t);
26
27
28
29
30struct key_type key_type_request_key_auth = {
31 .name = ".request_key_auth",
32 .def_datalen = sizeof(struct request_key_auth),
33 .preparse = request_key_auth_preparse,
34 .free_preparse = request_key_auth_free_preparse,
35 .instantiate = request_key_auth_instantiate,
36 .describe = request_key_auth_describe,
37 .revoke = request_key_auth_revoke,
38 .destroy = request_key_auth_destroy,
39 .read = request_key_auth_read,
40};
41
42static int request_key_auth_preparse(struct key_preparsed_payload *prep)
43{
44 return 0;
45}
46
47static void request_key_auth_free_preparse(struct key_preparsed_payload *prep)
48{
49}
50
51
52
53
54static int request_key_auth_instantiate(struct key *key,
55 struct key_preparsed_payload *prep)
56{
57 key->payload.data[0] = (struct request_key_auth *)prep->data;
58 return 0;
59}
60
61
62
63
64static void request_key_auth_describe(const struct key *key,
65 struct seq_file *m)
66{
67 struct request_key_auth *rka = get_request_key_auth(key);
68
69 seq_puts(m, "key:");
70 seq_puts(m, key->description);
71 if (key_is_positive(key))
72 seq_printf(m, " pid:%d ci:%zu", rka->pid, rka->callout_len);
73}
74
75
76
77
78
79static long request_key_auth_read(const struct key *key,
80 char __user *buffer, size_t buflen)
81{
82 struct request_key_auth *rka = get_request_key_auth(key);
83 size_t datalen;
84 long ret;
85
86 datalen = rka->callout_len;
87 ret = datalen;
88
89
90 if (buffer && buflen > 0) {
91 if (buflen > datalen)
92 buflen = datalen;
93
94 if (copy_to_user(buffer, rka->callout_info, buflen) != 0)
95 ret = -EFAULT;
96 }
97
98 return ret;
99}
100
101
102
103
104
105
106static void request_key_auth_revoke(struct key *key)
107{
108 struct request_key_auth *rka = get_request_key_auth(key);
109
110 kenter("{%d}", key->serial);
111
112 if (rka->cred) {
113 put_cred(rka->cred);
114 rka->cred = NULL;
115 }
116}
117
118static void free_request_key_auth(struct request_key_auth *rka)
119{
120 if (!rka)
121 return;
122 key_put(rka->target_key);
123 key_put(rka->dest_keyring);
124 if (rka->cred)
125 put_cred(rka->cred);
126 kfree(rka->callout_info);
127 kfree(rka);
128}
129
130
131
132
133static void request_key_auth_destroy(struct key *key)
134{
135 struct request_key_auth *rka = get_request_key_auth(key);
136
137 kenter("{%d}", key->serial);
138
139 free_request_key_auth(rka);
140}
141
142
143
144
145
146struct key *request_key_auth_new(struct key *target, const char *op,
147 const void *callout_info, size_t callout_len,
148 struct key *dest_keyring)
149{
150 struct request_key_auth *rka, *irka;
151 const struct cred *cred = current->cred;
152 struct key *authkey = NULL;
153 char desc[20];
154 int ret = -ENOMEM;
155
156 kenter("%d,", target->serial);
157
158
159 rka = kzalloc(sizeof(*rka), GFP_KERNEL);
160 if (!rka)
161 goto error;
162 rka->callout_info = kmemdup(callout_info, callout_len, GFP_KERNEL);
163 if (!rka->callout_info)
164 goto error_free_rka;
165 rka->callout_len = callout_len;
166 strlcpy(rka->op, op, sizeof(rka->op));
167
168
169
170 if (cred->request_key_auth) {
171
172 down_read(&cred->request_key_auth->sem);
173
174
175
176 if (test_bit(KEY_FLAG_REVOKED,
177 &cred->request_key_auth->flags)) {
178 up_read(&cred->request_key_auth->sem);
179 ret = -EKEYREVOKED;
180 goto error_free_rka;
181 }
182
183 irka = cred->request_key_auth->payload.data[0];
184 rka->cred = get_cred(irka->cred);
185 rka->pid = irka->pid;
186
187 up_read(&cred->request_key_auth->sem);
188 }
189 else {
190
191 rka->cred = get_cred(cred);
192 rka->pid = current->pid;
193 }
194
195 rka->target_key = key_get(target);
196 rka->dest_keyring = key_get(dest_keyring);
197
198
199 sprintf(desc, "%x", target->serial);
200
201 authkey = key_alloc(&key_type_request_key_auth, desc,
202 cred->fsuid, cred->fsgid, cred,
203 KEY_POS_VIEW | KEY_POS_READ | KEY_POS_SEARCH |
204 KEY_USR_VIEW, KEY_ALLOC_NOT_IN_QUOTA, NULL);
205 if (IS_ERR(authkey)) {
206 ret = PTR_ERR(authkey);
207 goto error_free_rka;
208 }
209
210
211 ret = key_instantiate_and_link(authkey, rka, 0, NULL, NULL);
212 if (ret < 0)
213 goto error_put_authkey;
214
215 kleave(" = {%d,%d}", authkey->serial, refcount_read(&authkey->usage));
216 return authkey;
217
218error_put_authkey:
219 key_put(authkey);
220error_free_rka:
221 free_request_key_auth(rka);
222error:
223 kleave("= %d", ret);
224 return ERR_PTR(ret);
225}
226
227
228
229
230
231struct key *key_get_instantiation_authkey(key_serial_t target_id)
232{
233 char description[16];
234 struct keyring_search_context ctx = {
235 .index_key.type = &key_type_request_key_auth,
236 .index_key.description = description,
237 .cred = current_cred(),
238 .match_data.cmp = key_default_cmp,
239 .match_data.raw_data = description,
240 .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
241 .flags = KEYRING_SEARCH_DO_STATE_CHECK,
242 };
243 struct key *authkey;
244 key_ref_t authkey_ref;
245
246 ctx.index_key.desc_len = sprintf(description, "%x", target_id);
247
248 authkey_ref = search_process_keyrings(&ctx);
249
250 if (IS_ERR(authkey_ref)) {
251 authkey = ERR_CAST(authkey_ref);
252 if (authkey == ERR_PTR(-EAGAIN))
253 authkey = ERR_PTR(-ENOKEY);
254 goto error;
255 }
256
257 authkey = key_ref_to_ptr(authkey_ref);
258 if (test_bit(KEY_FLAG_REVOKED, &authkey->flags)) {
259 key_put(authkey);
260 authkey = ERR_PTR(-EKEYREVOKED);
261 }
262
263error:
264 return authkey;
265}
266