1 // SPDX-License-Identifier: BSD-2-Clause
2 /*
3 * Copyright (c) 2018-2022 Linaro Limited
4 * Copyright (c) 2020, Arm Limited.
5 * Copyright (c) 2020, Open Mobile Platform LLC
6 */
7
8 #include <assert.h>
9 #include <crypto/crypto.h>
10 #include <kernel/huk_subkey.h>
11 #include <kernel/ldelf_loader.h>
12 #include <kernel/msg_param.h>
13 #include <kernel/pseudo_ta.h>
14 #include <kernel/tpm.h>
15 #include <kernel/user_access.h>
16 #include <kernel/user_mode_ctx.h>
17 #include <mm/file.h>
18 #include <mm/fobj.h>
19 #include <mm/vm.h>
20 #include <pta_system.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <tee_api_defines_extensions.h>
24 #include <tee_api_defines.h>
25 #include <tee/tee_supp_plugin_rpc.h>
26 #include <util.h>
27
28 static unsigned int system_pnum;
29
system_rng_reseed(uint32_t param_types,TEE_Param params[TEE_NUM_PARAMS])30 static TEE_Result system_rng_reseed(uint32_t param_types,
31 TEE_Param params[TEE_NUM_PARAMS])
32 {
33 size_t entropy_sz = 0;
34 uint8_t *entropy_input = NULL;
35 void *seed_bbuf = NULL;
36 TEE_Result res = TEE_SUCCESS;
37 uint32_t exp_pt = TEE_PARAM_TYPES(TEE_PARAM_TYPE_MEMREF_INPUT,
38 TEE_PARAM_TYPE_NONE,
39 TEE_PARAM_TYPE_NONE,
40 TEE_PARAM_TYPE_NONE);
41
42 if (exp_pt != param_types)
43 return TEE_ERROR_BAD_PARAMETERS;
44 entropy_input = params[0].memref.buffer;
45 entropy_sz = params[0].memref.size;
46
47 if (!entropy_sz || !entropy_input)
48 return TEE_ERROR_BAD_PARAMETERS;
49
50 res = bb_memdup_user(entropy_input, entropy_sz, &seed_bbuf);
51 if (res)
52 return res;
53
54 crypto_rng_add_event(CRYPTO_RNG_SRC_NONSECURE, &system_pnum,
55 seed_bbuf, entropy_sz);
56
57 bb_free(seed_bbuf, entropy_sz);
58
59 return TEE_SUCCESS;
60 }
61
system_derive_ta_unique_key(struct user_mode_ctx * uctx,uint32_t param_types,TEE_Param params[TEE_NUM_PARAMS])62 static TEE_Result system_derive_ta_unique_key(struct user_mode_ctx *uctx,
63 uint32_t param_types,
64 TEE_Param params[TEE_NUM_PARAMS])
65 {
66 size_t data_len = sizeof(TEE_UUID);
67 TEE_Result res = TEE_ERROR_GENERIC;
68 uint8_t *data = NULL;
69 uint32_t access_flags = 0;
70 void *subkey_bbuf = NULL;
71 uint32_t exp_pt = TEE_PARAM_TYPES(TEE_PARAM_TYPE_MEMREF_INPUT,
72 TEE_PARAM_TYPE_MEMREF_OUTPUT,
73 TEE_PARAM_TYPE_NONE,
74 TEE_PARAM_TYPE_NONE);
75
76 if (exp_pt != param_types)
77 return TEE_ERROR_BAD_PARAMETERS;
78
79 if (params[0].memref.size > TA_DERIVED_EXTRA_DATA_MAX_SIZE ||
80 params[1].memref.size < TA_DERIVED_KEY_MIN_SIZE ||
81 params[1].memref.size > TA_DERIVED_KEY_MAX_SIZE)
82 return TEE_ERROR_BAD_PARAMETERS;
83
84 /*
85 * The derived key shall not end up in non-secure memory by
86 * mistake.
87 *
88 * Note that we're allowing shared memory as long as it's
89 * secure. This is needed because a TA always uses shared memory
90 * when communicating with another TA.
91 */
92 access_flags = TEE_MEMORY_ACCESS_WRITE | TEE_MEMORY_ACCESS_ANY_OWNER |
93 TEE_MEMORY_ACCESS_SECURE;
94 res = vm_check_access_rights(uctx, access_flags,
95 (uaddr_t)params[1].memref.buffer,
96 params[1].memref.size);
97 if (res != TEE_SUCCESS)
98 return TEE_ERROR_SECURITY;
99
100 /* Take extra data into account. */
101 if (ADD_OVERFLOW(data_len, params[0].memref.size, &data_len))
102 return TEE_ERROR_SECURITY;
103
104 data = bb_alloc(data_len);
105 if (!data)
106 return TEE_ERROR_OUT_OF_MEMORY;
107
108 memcpy(data, &uctx->ts_ctx->uuid, sizeof(TEE_UUID));
109
110 /* Append the user provided data */
111 res = copy_from_user(data + sizeof(TEE_UUID), params[0].memref.buffer,
112 params[0].memref.size);
113 if (res)
114 goto out;
115
116 subkey_bbuf = bb_alloc(params[1].memref.size);
117 if (!subkey_bbuf) {
118 res = TEE_ERROR_OUT_OF_MEMORY;
119 goto out;
120 }
121
122 res = huk_subkey_derive(HUK_SUBKEY_UNIQUE_TA, data, data_len,
123 subkey_bbuf, params[1].memref.size);
124 if (res)
125 goto out;
126
127 res = copy_to_user(params[1].memref.buffer, subkey_bbuf,
128 params[1].memref.size);
129
130 out:
131 bb_free_wipe(subkey_bbuf, params[1].memref.size);
132 bb_free_wipe(data, data_len);
133 return res;
134 }
135
system_map_zi(struct user_mode_ctx * uctx,uint32_t param_types,TEE_Param params[TEE_NUM_PARAMS])136 static TEE_Result system_map_zi(struct user_mode_ctx *uctx,
137 uint32_t param_types,
138 TEE_Param params[TEE_NUM_PARAMS])
139 {
140 uint32_t exp_pt = TEE_PARAM_TYPES(TEE_PARAM_TYPE_VALUE_INPUT,
141 TEE_PARAM_TYPE_VALUE_INOUT,
142 TEE_PARAM_TYPE_VALUE_INPUT,
143 TEE_PARAM_TYPE_NONE);
144 uint32_t prot = TEE_MATTR_URW | TEE_MATTR_PRW;
145 TEE_Result res = TEE_ERROR_GENERIC;
146 struct mobj *mobj = NULL;
147 uint32_t pad_begin = 0;
148 uint32_t vm_flags = 0;
149 struct fobj *f = NULL;
150 uint32_t pad_end = 0;
151 size_t num_bytes = 0;
152 vaddr_t va = 0;
153
154 if (exp_pt != param_types)
155 return TEE_ERROR_BAD_PARAMETERS;
156 if (params[0].value.b & ~PTA_SYSTEM_MAP_FLAG_SHAREABLE)
157 return TEE_ERROR_BAD_PARAMETERS;
158
159 if (params[0].value.b & PTA_SYSTEM_MAP_FLAG_SHAREABLE)
160 vm_flags |= VM_FLAG_SHAREABLE;
161
162 num_bytes = params[0].value.a;
163 va = reg_pair_to_64(params[1].value.a, params[1].value.b);
164 pad_begin = params[2].value.a;
165 pad_end = params[2].value.b;
166
167 f = fobj_ta_mem_alloc(ROUNDUP_DIV(num_bytes, SMALL_PAGE_SIZE));
168 if (!f)
169 return TEE_ERROR_OUT_OF_MEMORY;
170 mobj = mobj_with_fobj_alloc(f, NULL, TEE_MATTR_MEM_TYPE_TAGGED);
171 fobj_put(f);
172 if (!mobj)
173 return TEE_ERROR_OUT_OF_MEMORY;
174 res = vm_map_pad(uctx, &va, num_bytes, prot, vm_flags,
175 mobj, 0, pad_begin, pad_end, 0);
176 mobj_put(mobj);
177 if (!res)
178 reg_pair_from_64(va, ¶ms[1].value.a, ¶ms[1].value.b);
179
180 return res;
181 }
182
system_unmap(struct user_mode_ctx * uctx,uint32_t param_types,TEE_Param params[TEE_NUM_PARAMS])183 static TEE_Result system_unmap(struct user_mode_ctx *uctx, uint32_t param_types,
184 TEE_Param params[TEE_NUM_PARAMS])
185 {
186 uint32_t exp_pt = TEE_PARAM_TYPES(TEE_PARAM_TYPE_VALUE_INPUT,
187 TEE_PARAM_TYPE_VALUE_INPUT,
188 TEE_PARAM_TYPE_NONE,
189 TEE_PARAM_TYPE_NONE);
190 TEE_Result res = TEE_SUCCESS;
191 uint32_t vm_flags = 0;
192 vaddr_t end_va = 0;
193 vaddr_t va = 0;
194 size_t sz = 0;
195
196 if (exp_pt != param_types)
197 return TEE_ERROR_BAD_PARAMETERS;
198
199 if (params[0].value.b)
200 return TEE_ERROR_BAD_PARAMETERS;
201
202 va = reg_pair_to_64(params[1].value.a, params[1].value.b);
203 sz = ROUNDUP(params[0].value.a, SMALL_PAGE_SIZE);
204
205 /*
206 * The vm_get_flags() and vm_unmap() are supposed to detect or
207 * handle overflow directly or indirectly. However, this function
208 * an API function so an extra guard here is in order. If nothing
209 * else to make it easier to review the code.
210 */
211 if (ADD_OVERFLOW(va, sz, &end_va))
212 return TEE_ERROR_BAD_PARAMETERS;
213
214 res = vm_get_flags(uctx, va, sz, &vm_flags);
215 if (res)
216 return res;
217 if (vm_flags & VM_FLAG_PERMANENT)
218 return TEE_ERROR_ACCESS_DENIED;
219
220 return vm_unmap(uctx, va, sz);
221 }
222
system_dlopen(struct user_mode_ctx * uctx,uint32_t param_types,TEE_Param params[TEE_NUM_PARAMS])223 static TEE_Result system_dlopen(struct user_mode_ctx *uctx,
224 uint32_t param_types,
225 TEE_Param params[TEE_NUM_PARAMS])
226 {
227 uint32_t exp_pt = TEE_PARAM_TYPES(TEE_PARAM_TYPE_MEMREF_INPUT,
228 TEE_PARAM_TYPE_VALUE_INPUT,
229 TEE_PARAM_TYPE_NONE,
230 TEE_PARAM_TYPE_NONE);
231 TEE_Result res = TEE_ERROR_GENERIC;
232 struct ts_session *s = NULL;
233 TEE_UUID uuid = { };
234 uint32_t flags = 0;
235
236 if (exp_pt != param_types)
237 return TEE_ERROR_BAD_PARAMETERS;
238
239 if (!params[0].memref.buffer || params[0].memref.size != sizeof(uuid))
240 return TEE_ERROR_BAD_PARAMETERS;
241
242 res = copy_from_user(&uuid, params[0].memref.buffer, sizeof(uuid));
243 if (res)
244 return res;
245
246 flags = params[1].value.a;
247
248 s = ts_pop_current_session();
249 res = ldelf_dlopen(uctx, &uuid, flags);
250 ts_push_current_session(s);
251
252 return res;
253 }
254
system_dlsym(struct user_mode_ctx * uctx,uint32_t param_types,TEE_Param params[TEE_NUM_PARAMS])255 static TEE_Result system_dlsym(struct user_mode_ctx *uctx, uint32_t param_types,
256 TEE_Param params[TEE_NUM_PARAMS])
257 {
258 uint32_t exp_pt = TEE_PARAM_TYPES(TEE_PARAM_TYPE_MEMREF_INPUT,
259 TEE_PARAM_TYPE_MEMREF_INPUT,
260 TEE_PARAM_TYPE_VALUE_OUTPUT,
261 TEE_PARAM_TYPE_NONE);
262 TEE_Result res = TEE_ERROR_GENERIC;
263 struct ts_session *s = NULL;
264 char *sym = NULL;
265 TEE_UUID uuid = { };
266 size_t symlen = 0;
267 vaddr_t va = 0;
268
269 if (exp_pt != param_types)
270 return TEE_ERROR_BAD_PARAMETERS;
271
272 if (!params[0].memref.buffer || params[0].memref.size != sizeof(uuid))
273 return TEE_ERROR_BAD_PARAMETERS;
274
275 res = copy_from_user(&uuid, params[0].memref.buffer, sizeof(uuid));
276 if (res)
277 return res;
278
279 if (!params[1].memref.buffer)
280 return TEE_ERROR_BAD_PARAMETERS;
281 res = bb_strndup_user(params[1].memref.buffer, params[1].memref.size,
282 &sym, &symlen);
283 if (res)
284 return res;
285
286 s = ts_pop_current_session();
287 res = ldelf_dlsym(uctx, &uuid, sym, symlen, &va);
288 ts_push_current_session(s);
289
290 if (!res)
291 reg_pair_from_64(va, ¶ms[2].value.a, ¶ms[2].value.b);
292
293 return res;
294 }
295
system_get_tpm_event_log(uint32_t param_types,TEE_Param params[TEE_NUM_PARAMS])296 static TEE_Result system_get_tpm_event_log(uint32_t param_types,
297 TEE_Param params[TEE_NUM_PARAMS])
298 {
299 uint32_t exp_pt = TEE_PARAM_TYPES(TEE_PARAM_TYPE_MEMREF_OUTPUT,
300 TEE_PARAM_TYPE_NONE,
301 TEE_PARAM_TYPE_NONE,
302 TEE_PARAM_TYPE_NONE);
303 size_t size = 0;
304 TEE_Result res = TEE_SUCCESS;
305
306 if (exp_pt != param_types)
307 return TEE_ERROR_BAD_PARAMETERS;
308
309 size = params[0].memref.size;
310 res = tpm_get_event_log(params[0].memref.buffer, &size);
311 params[0].memref.size = size;
312
313 return res;
314 }
315
system_supp_plugin_invoke(uint32_t param_types,TEE_Param params[TEE_NUM_PARAMS])316 static TEE_Result system_supp_plugin_invoke(uint32_t param_types,
317 TEE_Param params[TEE_NUM_PARAMS])
318 {
319 uint32_t exp_pt = TEE_PARAM_TYPES(TEE_PARAM_TYPE_MEMREF_INPUT,
320 TEE_PARAM_TYPE_VALUE_INPUT,
321 TEE_PARAM_TYPE_MEMREF_INOUT,
322 TEE_PARAM_TYPE_VALUE_OUTPUT);
323 TEE_Result res = TEE_ERROR_GENERIC;
324 size_t outlen = 0;
325 TEE_UUID uuid = { };
326
327 if (exp_pt != param_types)
328 return TEE_ERROR_BAD_PARAMETERS;
329
330 if (!params[0].memref.buffer || params[0].memref.size != sizeof(uuid))
331 return TEE_ERROR_BAD_PARAMETERS;
332
333 res = copy_from_user(&uuid, params[0].memref.buffer, sizeof(uuid));
334 if (res)
335 return res;
336
337 res = tee_invoke_supp_plugin_rpc(&uuid,
338 params[1].value.a, /* cmd */
339 params[1].value.b, /* sub_cmd */
340 NULL,
341 params[2].memref.buffer, /* data */
342 params[2].memref.size, /* in len */
343 &outlen);
344 params[3].value.a = (uint32_t)outlen;
345
346 return res;
347 }
348
open_session(uint32_t param_types __unused,TEE_Param params[TEE_NUM_PARAMS]__unused,void ** sess_ctx __unused)349 static TEE_Result open_session(uint32_t param_types __unused,
350 TEE_Param params[TEE_NUM_PARAMS] __unused,
351 void **sess_ctx __unused)
352 {
353 struct ts_session *s = NULL;
354
355 /* Check that we're called from a user TA */
356 s = ts_get_calling_session();
357 if (!s)
358 return TEE_ERROR_ACCESS_DENIED;
359 if (!is_user_ta_ctx(s->ctx))
360 return TEE_ERROR_ACCESS_DENIED;
361
362 return TEE_SUCCESS;
363 }
364
invoke_command(void * sess_ctx __unused,uint32_t cmd_id,uint32_t param_types,TEE_Param params[TEE_NUM_PARAMS])365 static TEE_Result invoke_command(void *sess_ctx __unused, uint32_t cmd_id,
366 uint32_t param_types,
367 TEE_Param params[TEE_NUM_PARAMS])
368 {
369 struct ts_session *s = ts_get_calling_session();
370 struct user_mode_ctx *uctx = to_user_mode_ctx(s->ctx);
371
372 switch (cmd_id) {
373 case PTA_SYSTEM_ADD_RNG_ENTROPY:
374 return system_rng_reseed(param_types, params);
375 case PTA_SYSTEM_DERIVE_TA_UNIQUE_KEY:
376 return system_derive_ta_unique_key(uctx, param_types, params);
377 case PTA_SYSTEM_MAP_ZI:
378 return system_map_zi(uctx, param_types, params);
379 case PTA_SYSTEM_UNMAP:
380 return system_unmap(uctx, param_types, params);
381 case PTA_SYSTEM_DLOPEN:
382 return system_dlopen(uctx, param_types, params);
383 case PTA_SYSTEM_DLSYM:
384 return system_dlsym(uctx, param_types, params);
385 case PTA_SYSTEM_GET_TPM_EVENT_LOG:
386 return system_get_tpm_event_log(param_types, params);
387 case PTA_SYSTEM_SUPP_PLUGIN_INVOKE:
388 return system_supp_plugin_invoke(param_types, params);
389 default:
390 break;
391 }
392
393 return TEE_ERROR_NOT_IMPLEMENTED;
394 }
395
396 pseudo_ta_register(.uuid = PTA_SYSTEM_UUID, .name = "system.pta",
397 .flags = PTA_DEFAULT_FLAGS | TA_FLAG_CONCURRENT,
398 .open_session_entry_point = open_session,
399 .invoke_command_entry_point = invoke_command);
400