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9#include <keys/user-type.h>
10#include <keys/trusted-type.h>
11#include <keys/trusted_tee.h>
12#include <keys/trusted_tpm.h>
13#include <linux/capability.h>
14#include <linux/err.h>
15#include <linux/init.h>
16#include <linux/key-type.h>
17#include <linux/module.h>
18#include <linux/parser.h>
19#include <linux/rcupdate.h>
20#include <linux/slab.h>
21#include <linux/static_call.h>
22#include <linux/string.h>
23#include <linux/uaccess.h>
24
25static char *trusted_key_source;
26module_param_named(source, trusted_key_source, charp, 0);
27MODULE_PARM_DESC(source, "Select trusted keys source (tpm or tee)");
28
29static const struct trusted_key_source trusted_key_sources[] = {
30#if defined(CONFIG_TCG_TPM)
31 { "tpm", &trusted_key_tpm_ops },
32#endif
33#if defined(CONFIG_TEE)
34 { "tee", &trusted_key_tee_ops },
35#endif
36};
37
38DEFINE_STATIC_CALL_NULL(trusted_key_init, *trusted_key_sources[0].ops->init);
39DEFINE_STATIC_CALL_NULL(trusted_key_seal, *trusted_key_sources[0].ops->seal);
40DEFINE_STATIC_CALL_NULL(trusted_key_unseal,
41 *trusted_key_sources[0].ops->unseal);
42DEFINE_STATIC_CALL_NULL(trusted_key_get_random,
43 *trusted_key_sources[0].ops->get_random);
44DEFINE_STATIC_CALL_NULL(trusted_key_exit, *trusted_key_sources[0].ops->exit);
45static unsigned char migratable;
46
47enum {
48 Opt_err,
49 Opt_new, Opt_load, Opt_update,
50};
51
52static const match_table_t key_tokens = {
53 {Opt_new, "new"},
54 {Opt_load, "load"},
55 {Opt_update, "update"},
56 {Opt_err, NULL}
57};
58
59
60
61
62
63
64
65static int datablob_parse(char **datablob, struct trusted_key_payload *p)
66{
67 substring_t args[MAX_OPT_ARGS];
68 long keylen;
69 int ret = -EINVAL;
70 int key_cmd;
71 char *c;
72
73
74 c = strsep(datablob, " \t");
75 if (!c)
76 return -EINVAL;
77 key_cmd = match_token(c, key_tokens, args);
78 switch (key_cmd) {
79 case Opt_new:
80
81 c = strsep(datablob, " \t");
82 if (!c)
83 return -EINVAL;
84 ret = kstrtol(c, 10, &keylen);
85 if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)
86 return -EINVAL;
87 p->key_len = keylen;
88 ret = Opt_new;
89 break;
90 case Opt_load:
91
92 c = strsep(datablob, " \t");
93 if (!c)
94 return -EINVAL;
95 p->blob_len = strlen(c) / 2;
96 if (p->blob_len > MAX_BLOB_SIZE)
97 return -EINVAL;
98 ret = hex2bin(p->blob, c, p->blob_len);
99 if (ret < 0)
100 return -EINVAL;
101 ret = Opt_load;
102 break;
103 case Opt_update:
104 ret = Opt_update;
105 break;
106 case Opt_err:
107 return -EINVAL;
108 }
109 return ret;
110}
111
112static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
113{
114 struct trusted_key_payload *p = NULL;
115 int ret;
116
117 ret = key_payload_reserve(key, sizeof(*p));
118 if (ret < 0)
119 goto err;
120 p = kzalloc(sizeof(*p), GFP_KERNEL);
121 if (!p)
122 goto err;
123
124 p->migratable = migratable;
125err:
126 return p;
127}
128
129
130
131
132
133
134
135
136
137
138static int trusted_instantiate(struct key *key,
139 struct key_preparsed_payload *prep)
140{
141 struct trusted_key_payload *payload = NULL;
142 size_t datalen = prep->datalen;
143 char *datablob, *orig_datablob;
144 int ret = 0;
145 int key_cmd;
146 size_t key_len;
147
148 if (datalen <= 0 || datalen > 32767 || !prep->data)
149 return -EINVAL;
150
151 orig_datablob = datablob = kmalloc(datalen + 1, GFP_KERNEL);
152 if (!datablob)
153 return -ENOMEM;
154 memcpy(datablob, prep->data, datalen);
155 datablob[datalen] = '\0';
156
157 payload = trusted_payload_alloc(key);
158 if (!payload) {
159 ret = -ENOMEM;
160 goto out;
161 }
162
163 key_cmd = datablob_parse(&datablob, payload);
164 if (key_cmd < 0) {
165 ret = key_cmd;
166 goto out;
167 }
168
169 dump_payload(payload);
170
171 switch (key_cmd) {
172 case Opt_load:
173 ret = static_call(trusted_key_unseal)(payload, datablob);
174 dump_payload(payload);
175 if (ret < 0)
176 pr_info("key_unseal failed (%d)\n", ret);
177 break;
178 case Opt_new:
179 key_len = payload->key_len;
180 ret = static_call(trusted_key_get_random)(payload->key,
181 key_len);
182 if (ret < 0)
183 goto out;
184
185 if (ret != key_len) {
186 pr_info("key_create failed (%d)\n", ret);
187 ret = -EIO;
188 goto out;
189 }
190
191 ret = static_call(trusted_key_seal)(payload, datablob);
192 if (ret < 0)
193 pr_info("key_seal failed (%d)\n", ret);
194 break;
195 default:
196 ret = -EINVAL;
197 }
198out:
199 kfree_sensitive(orig_datablob);
200 if (!ret)
201 rcu_assign_keypointer(key, payload);
202 else
203 kfree_sensitive(payload);
204 return ret;
205}
206
207static void trusted_rcu_free(struct rcu_head *rcu)
208{
209 struct trusted_key_payload *p;
210
211 p = container_of(rcu, struct trusted_key_payload, rcu);
212 kfree_sensitive(p);
213}
214
215
216
217
218static int trusted_update(struct key *key, struct key_preparsed_payload *prep)
219{
220 struct trusted_key_payload *p;
221 struct trusted_key_payload *new_p;
222 size_t datalen = prep->datalen;
223 char *datablob, *orig_datablob;
224 int ret = 0;
225
226 if (key_is_negative(key))
227 return -ENOKEY;
228 p = key->payload.data[0];
229 if (!p->migratable)
230 return -EPERM;
231 if (datalen <= 0 || datalen > 32767 || !prep->data)
232 return -EINVAL;
233
234 orig_datablob = datablob = kmalloc(datalen + 1, GFP_KERNEL);
235 if (!datablob)
236 return -ENOMEM;
237
238 new_p = trusted_payload_alloc(key);
239 if (!new_p) {
240 ret = -ENOMEM;
241 goto out;
242 }
243
244 memcpy(datablob, prep->data, datalen);
245 datablob[datalen] = '\0';
246 ret = datablob_parse(&datablob, new_p);
247 if (ret != Opt_update) {
248 ret = -EINVAL;
249 kfree_sensitive(new_p);
250 goto out;
251 }
252
253
254 new_p->migratable = p->migratable;
255 new_p->key_len = p->key_len;
256 memcpy(new_p->key, p->key, p->key_len);
257 dump_payload(p);
258 dump_payload(new_p);
259
260 ret = static_call(trusted_key_seal)(new_p, datablob);
261 if (ret < 0) {
262 pr_info("key_seal failed (%d)\n", ret);
263 kfree_sensitive(new_p);
264 goto out;
265 }
266
267 rcu_assign_keypointer(key, new_p);
268 call_rcu(&p->rcu, trusted_rcu_free);
269out:
270 kfree_sensitive(orig_datablob);
271 return ret;
272}
273
274
275
276
277
278static long trusted_read(const struct key *key, char *buffer,
279 size_t buflen)
280{
281 const struct trusted_key_payload *p;
282 char *bufp;
283 int i;
284
285 p = dereference_key_locked(key);
286 if (!p)
287 return -EINVAL;
288
289 if (buffer && buflen >= 2 * p->blob_len) {
290 bufp = buffer;
291 for (i = 0; i < p->blob_len; i++)
292 bufp = hex_byte_pack(bufp, p->blob[i]);
293 }
294 return 2 * p->blob_len;
295}
296
297
298
299
300static void trusted_destroy(struct key *key)
301{
302 kfree_sensitive(key->payload.data[0]);
303}
304
305struct key_type key_type_trusted = {
306 .name = "trusted",
307 .instantiate = trusted_instantiate,
308 .update = trusted_update,
309 .destroy = trusted_destroy,
310 .describe = user_describe,
311 .read = trusted_read,
312};
313EXPORT_SYMBOL_GPL(key_type_trusted);
314
315static int __init init_trusted(void)
316{
317 int i, ret = 0;
318
319 for (i = 0; i < ARRAY_SIZE(trusted_key_sources); i++) {
320 if (trusted_key_source &&
321 strncmp(trusted_key_source, trusted_key_sources[i].name,
322 strlen(trusted_key_sources[i].name)))
323 continue;
324
325 static_call_update(trusted_key_init,
326 trusted_key_sources[i].ops->init);
327 static_call_update(trusted_key_seal,
328 trusted_key_sources[i].ops->seal);
329 static_call_update(trusted_key_unseal,
330 trusted_key_sources[i].ops->unseal);
331 static_call_update(trusted_key_get_random,
332 trusted_key_sources[i].ops->get_random);
333 static_call_update(trusted_key_exit,
334 trusted_key_sources[i].ops->exit);
335 migratable = trusted_key_sources[i].ops->migratable;
336
337 ret = static_call(trusted_key_init)();
338 if (!ret)
339 break;
340 }
341
342
343
344
345
346 if (ret == -ENODEV)
347 return 0;
348
349 return ret;
350}
351
352static void __exit cleanup_trusted(void)
353{
354 static_call(trusted_key_exit)();
355}
356
357late_initcall(init_trusted);
358module_exit(cleanup_trusted);
359
360MODULE_LICENSE("GPL");
361