xref: /optee_os/ta/pkcs11/src/processing.c (revision fa247a2a296e38934a5835558abd4ec5f1209a94)
1 // SPDX-License-Identifier: BSD-2-Clause
2 /*
3  * Copyright (c) 2017-2020, Linaro Limited
4  */
5 
6 #include <assert.h>
7 #include <pkcs11_ta.h>
8 #include <string.h>
9 #include <tee_api_defines.h>
10 #include <tee_internal_api.h>
11 #include <tee_internal_api_extensions.h>
12 #include <util.h>
13 
14 #include "attributes.h"
15 #include "object.h"
16 #include "pkcs11_attributes.h"
17 #include "pkcs11_helpers.h"
18 #include "pkcs11_token.h"
19 #include "processing.h"
20 #include "serializer.h"
21 
22 static enum pkcs11_rc get_ready_session(struct pkcs11_session *session)
23 {
24 	if (session_is_active(session))
25 		return PKCS11_CKR_OPERATION_ACTIVE;
26 
27 	return PKCS11_CKR_OK;
28 }
29 
30 static bool func_matches_state(enum processing_func function,
31 			       enum pkcs11_proc_state state)
32 {
33 	switch (function) {
34 	case PKCS11_FUNCTION_ENCRYPT:
35 		return state == PKCS11_SESSION_ENCRYPTING ||
36 		       state == PKCS11_SESSION_DIGESTING_ENCRYPTING ||
37 		       state == PKCS11_SESSION_SIGNING_ENCRYPTING;
38 	case PKCS11_FUNCTION_DECRYPT:
39 		return state == PKCS11_SESSION_DECRYPTING ||
40 		       state == PKCS11_SESSION_DECRYPTING_DIGESTING ||
41 		       state == PKCS11_SESSION_DECRYPTING_VERIFYING;
42 	case PKCS11_FUNCTION_DIGEST:
43 		return state == PKCS11_SESSION_DIGESTING ||
44 		       state == PKCS11_SESSION_DIGESTING_ENCRYPTING;
45 	case PKCS11_FUNCTION_SIGN:
46 		return state == PKCS11_SESSION_SIGNING ||
47 		       state == PKCS11_SESSION_SIGNING_ENCRYPTING;
48 	case PKCS11_FUNCTION_VERIFY:
49 		return state == PKCS11_SESSION_VERIFYING ||
50 		       state == PKCS11_SESSION_DECRYPTING_VERIFYING;
51 	case PKCS11_FUNCTION_SIGN_RECOVER:
52 		return state == PKCS11_SESSION_SIGNING_RECOVER;
53 	case PKCS11_FUNCTION_VERIFY_RECOVER:
54 		return state == PKCS11_SESSION_SIGNING_RECOVER;
55 	default:
56 		TEE_Panic(function);
57 		return false;
58 	}
59 }
60 
61 static enum pkcs11_rc get_active_session(struct pkcs11_session *session,
62 					 enum processing_func function)
63 {
64 	enum pkcs11_rc rc = PKCS11_CKR_OPERATION_NOT_INITIALIZED;
65 
66 	if (session->processing &&
67 	    func_matches_state(function, session->processing->state))
68 		rc = PKCS11_CKR_OK;
69 
70 	return rc;
71 }
72 
73 void release_active_processing(struct pkcs11_session *session)
74 {
75 	if (!session->processing)
76 		return;
77 
78 	if (session->processing->tee_op_handle != TEE_HANDLE_NULL) {
79 		TEE_FreeOperation(session->processing->tee_op_handle);
80 		session->processing->tee_op_handle = TEE_HANDLE_NULL;
81 	}
82 
83 	TEE_Free(session->processing->extra_ctx);
84 
85 	TEE_Free(session->processing);
86 	session->processing = NULL;
87 }
88 
89 size_t get_object_key_bit_size(struct pkcs11_object *obj)
90 {
91 	uint32_t a_size = 0;
92 	struct obj_attrs *attrs = obj->attributes;
93 
94 	switch (get_key_type(attrs)) {
95 	case PKCS11_CKK_AES:
96 	case PKCS11_CKK_GENERIC_SECRET:
97 	case PKCS11_CKK_MD5_HMAC:
98 	case PKCS11_CKK_SHA_1_HMAC:
99 	case PKCS11_CKK_SHA224_HMAC:
100 	case PKCS11_CKK_SHA256_HMAC:
101 	case PKCS11_CKK_SHA384_HMAC:
102 	case PKCS11_CKK_SHA512_HMAC:
103 		if (get_attribute_ptr(attrs, PKCS11_CKA_VALUE, NULL, &a_size))
104 			return 0;
105 
106 		return a_size * 8;
107 	default:
108 		TEE_Panic(0);
109 		return 0;
110 	}
111 }
112 
113 static enum pkcs11_rc generate_random_key_value(struct obj_attrs **head)
114 {
115 	enum pkcs11_rc rc = PKCS11_CKR_GENERAL_ERROR;
116 	void *data = NULL;
117 	uint32_t data_size = 0;
118 	uint32_t value_len = 0;
119 	void *value = NULL;
120 
121 	if (!*head)
122 		return PKCS11_CKR_TEMPLATE_INCONSISTENT;
123 
124 	rc = get_attribute_ptr(*head, PKCS11_CKA_VALUE_LEN, &data, &data_size);
125 	if (rc || data_size != sizeof(uint32_t)) {
126 		DMSG("%s", rc ? "No attribute value_len found" :
127 		     "Invalid size for attribute VALUE_LEN");
128 
129 		return PKCS11_CKR_ATTRIBUTE_VALUE_INVALID;
130 	}
131 	TEE_MemMove(&value_len, data, data_size);
132 
133 	if (get_key_type(*head) == PKCS11_CKK_GENERIC_SECRET)
134 		value_len = (value_len + 7) / 8;
135 
136 	/* Remove the default empty value attribute if found */
137 	rc = remove_empty_attribute(head, PKCS11_CKA_VALUE);
138 	if (rc != PKCS11_CKR_OK && rc != PKCS11_RV_NOT_FOUND)
139 		return PKCS11_CKR_GENERAL_ERROR;
140 
141 	value = TEE_Malloc(value_len, TEE_USER_MEM_HINT_NO_FILL_ZERO);
142 	if (!value)
143 		return PKCS11_CKR_DEVICE_MEMORY;
144 
145 	TEE_GenerateRandom(value, value_len);
146 
147 	rc = add_attribute(head, PKCS11_CKA_VALUE, value, value_len);
148 
149 	TEE_Free(value);
150 
151 	return rc;
152 }
153 
154 enum pkcs11_rc entry_generate_secret(struct pkcs11_client *client,
155 				     uint32_t ptypes, TEE_Param *params)
156 {
157 	const uint32_t exp_pt = TEE_PARAM_TYPES(TEE_PARAM_TYPE_MEMREF_INOUT,
158 						TEE_PARAM_TYPE_NONE,
159 						TEE_PARAM_TYPE_MEMREF_OUTPUT,
160 						TEE_PARAM_TYPE_NONE);
161 	TEE_Param *ctrl = params;
162 	TEE_Param *out = params + 2;
163 	enum pkcs11_rc rc = PKCS11_CKR_GENERAL_ERROR;
164 	struct serialargs ctrlargs = { };
165 	struct pkcs11_session *session = NULL;
166 	struct pkcs11_attribute_head *proc_params = NULL;
167 	struct obj_attrs *head = NULL;
168 	struct pkcs11_object_head *template = NULL;
169 	size_t template_size = 0;
170 	uint32_t obj_handle = 0;
171 
172 	if (!client || ptypes != exp_pt ||
173 	    out->memref.size != sizeof(obj_handle))
174 		return PKCS11_CKR_ARGUMENTS_BAD;
175 
176 	serialargs_init(&ctrlargs, ctrl->memref.buffer, ctrl->memref.size);
177 
178 	rc = serialargs_get_session_from_handle(&ctrlargs, client, &session);
179 	if (rc)
180 		return rc;
181 
182 	rc = serialargs_alloc_get_one_attribute(&ctrlargs, &proc_params);
183 	if (rc)
184 		goto out;
185 
186 	rc = serialargs_alloc_get_attributes(&ctrlargs, &template);
187 	if (rc)
188 		goto out;
189 
190 	if (serialargs_remaining_bytes(&ctrlargs)) {
191 		rc = PKCS11_CKR_ARGUMENTS_BAD;
192 		goto out;
193 	}
194 
195 	rc = get_ready_session(session);
196 	if (rc)
197 		goto out;
198 
199 	template_size = sizeof(*template) + template->attrs_size;
200 
201 	rc = check_mechanism_against_processing(session, proc_params->id,
202 						PKCS11_FUNCTION_GENERATE,
203 						PKCS11_FUNC_STEP_INIT);
204 	if (rc) {
205 		DMSG("Invalid mechanism %#"PRIx32": %#x", proc_params->id, rc);
206 		goto out;
207 	}
208 
209 	/*
210 	 * Prepare a clean initial state for the requested object attributes.
211 	 * Free temporary template once done.
212 	 */
213 	rc = create_attributes_from_template(&head, template, template_size,
214 					     NULL, PKCS11_FUNCTION_GENERATE,
215 					     proc_params->id);
216 	if (rc)
217 		goto out;
218 
219 	TEE_Free(template);
220 	template = NULL;
221 
222 	rc = check_created_attrs(head, NULL);
223 	if (rc)
224 		goto out;
225 
226 	rc = check_created_attrs_against_processing(proc_params->id, head);
227 	if (rc)
228 		goto out;
229 
230 	rc = check_created_attrs_against_token(session, head);
231 	if (rc)
232 		goto out;
233 
234 	/*
235 	 * Execute target processing and add value as attribute
236 	 * PKCS11_CKA_VALUE. Symm key generation: depends on target
237 	 * processing to be used.
238 	 */
239 	switch (proc_params->id) {
240 	case PKCS11_CKM_GENERIC_SECRET_KEY_GEN:
241 	case PKCS11_CKM_AES_KEY_GEN:
242 		/* Generate random of size specified by attribute VALUE_LEN */
243 		rc = generate_random_key_value(&head);
244 		if (rc)
245 			goto out;
246 		break;
247 
248 	default:
249 		rc = PKCS11_CKR_MECHANISM_INVALID;
250 		goto out;
251 	}
252 
253 	TEE_Free(proc_params);
254 	proc_params = NULL;
255 
256 	/*
257 	 * Object is ready, register it and return a handle.
258 	 */
259 	rc = create_object(session, head, &obj_handle);
260 	if (rc)
261 		goto out;
262 
263 	/*
264 	 * Now obj_handle (through the related struct pkcs11_object instance)
265 	 * owns the serialized buffer that holds the object attributes.
266 	 * We reset head to NULL as it is no more the buffer owner and would
267 	 * be freed at function out.
268 	 */
269 	head = NULL;
270 
271 	TEE_MemMove(out->memref.buffer, &obj_handle, sizeof(obj_handle));
272 	out->memref.size = sizeof(obj_handle);
273 
274 	DMSG("PKCS11 session %"PRIu32": generate secret %#"PRIx32,
275 	     session->handle, obj_handle);
276 
277 out:
278 	TEE_Free(proc_params);
279 	TEE_Free(template);
280 	TEE_Free(head);
281 
282 	return rc;
283 }
284 
285 /*
286  * entry_processing_init - Generic entry for initializing a processing
287  *
288  * @client = client reference
289  * @ptype = Invocation parameter types
290  * @params = Invocation parameters reference
291  * @function - encrypt, decrypt, sign, verify, digest, ...
292  */
293 enum pkcs11_rc entry_processing_init(struct pkcs11_client *client,
294 				     uint32_t ptypes, TEE_Param *params,
295 				     enum processing_func function)
296 {
297 	const uint32_t exp_pt = TEE_PARAM_TYPES(TEE_PARAM_TYPE_MEMREF_INOUT,
298 						TEE_PARAM_TYPE_NONE,
299 						TEE_PARAM_TYPE_NONE,
300 						TEE_PARAM_TYPE_NONE);
301 	TEE_Param *ctrl = params;
302 	enum pkcs11_rc rc = PKCS11_CKR_OK;
303 	struct serialargs ctrlargs = { };
304 	struct pkcs11_session *session = NULL;
305 	struct pkcs11_attribute_head *proc_params = NULL;
306 	uint32_t key_handle = 0;
307 	struct pkcs11_object *obj = NULL;
308 
309 	if (!client || ptypes != exp_pt)
310 		return PKCS11_CKR_ARGUMENTS_BAD;
311 
312 	serialargs_init(&ctrlargs, ctrl->memref.buffer, ctrl->memref.size);
313 
314 	rc = serialargs_get_session_from_handle(&ctrlargs, client, &session);
315 	if (rc)
316 		return rc;
317 
318 	rc = serialargs_get(&ctrlargs, &key_handle, sizeof(uint32_t));
319 	if (rc)
320 		return rc;
321 
322 	rc = serialargs_alloc_get_one_attribute(&ctrlargs, &proc_params);
323 	if (rc)
324 		return rc;
325 
326 	if (serialargs_remaining_bytes(&ctrlargs)) {
327 		rc = PKCS11_CKR_ARGUMENTS_BAD;
328 		goto out;
329 	}
330 
331 	rc = get_ready_session(session);
332 	if (rc)
333 		goto out;
334 
335 	obj = pkcs11_handle2object(key_handle, session);
336 	if (!obj) {
337 		rc = PKCS11_CKR_KEY_HANDLE_INVALID;
338 		goto out;
339 	}
340 
341 	rc = set_processing_state(session, function, obj, NULL);
342 	if (rc)
343 		goto out;
344 
345 	rc = check_mechanism_against_processing(session, proc_params->id,
346 						function,
347 						PKCS11_FUNC_STEP_INIT);
348 	if (rc)
349 		goto out;
350 
351 	rc = check_parent_attrs_against_processing(proc_params->id, function,
352 						   obj->attributes);
353 	if (rc)
354 		goto out;
355 
356 	rc = check_access_attrs_against_token(session, obj->attributes);
357 	if (rc)
358 		goto out;
359 
360 	if (processing_is_tee_symm(proc_params->id))
361 		rc = init_symm_operation(session, function, proc_params, obj);
362 	else
363 		rc = PKCS11_CKR_MECHANISM_INVALID;
364 
365 	if (rc == PKCS11_CKR_OK) {
366 		session->processing->mecha_type = proc_params->id;
367 		DMSG("PKCS11 session %"PRIu32": init processing %s %s",
368 		     session->handle, id2str_proc(proc_params->id),
369 		     id2str_function(function));
370 	}
371 
372 out:
373 	if (rc && session)
374 		release_active_processing(session);
375 
376 	TEE_Free(proc_params);
377 
378 	return rc;
379 }
380 
381 /*
382  * entry_processing_step - Generic entry on active processing
383  *
384  * @client = client reference
385  * @ptype = Invocation parameter types
386  * @params = Invocation parameters reference
387  * @function - encrypt, decrypt, sign, verify, digest, ...
388  * @step - update, oneshot, final
389  */
390 enum pkcs11_rc entry_processing_step(struct pkcs11_client *client,
391 				     uint32_t ptypes, TEE_Param *params,
392 				     enum processing_func function,
393 				     enum processing_step step)
394 {
395 	TEE_Param *ctrl = params;
396 	enum pkcs11_rc rc = PKCS11_CKR_OK;
397 	struct serialargs ctrlargs = { };
398 	struct pkcs11_session *session = NULL;
399 	enum pkcs11_mechanism_id mecha_type = PKCS11_CKM_UNDEFINED_ID;
400 
401 	if (!client ||
402 	    TEE_PARAM_TYPE_GET(ptypes, 0) != TEE_PARAM_TYPE_MEMREF_INOUT)
403 		return PKCS11_CKR_ARGUMENTS_BAD;
404 
405 	serialargs_init(&ctrlargs, ctrl->memref.buffer, ctrl->memref.size);
406 
407 	rc = serialargs_get_session_from_handle(&ctrlargs, client, &session);
408 	if (rc)
409 		return rc;
410 
411 	if (serialargs_remaining_bytes(&ctrlargs))
412 		return PKCS11_CKR_ARGUMENTS_BAD;
413 
414 	rc = get_active_session(session, function);
415 	if (rc)
416 		return rc;
417 
418 	mecha_type = session->processing->mecha_type;
419 	rc = check_mechanism_against_processing(session, mecha_type,
420 						function, step);
421 	if (rc)
422 		goto out;
423 
424 	if (processing_is_tee_symm(mecha_type))
425 		rc = step_symm_operation(session, function, step,
426 					 ptypes, params);
427 	else
428 		rc = PKCS11_CKR_MECHANISM_INVALID;
429 
430 	if (rc == PKCS11_CKR_OK && step == PKCS11_FUNC_STEP_UPDATE) {
431 		session->processing->updated = true;
432 		DMSG("PKCS11 session%"PRIu32": processing %s %s",
433 		     session->handle, id2str_proc(mecha_type),
434 		     id2str_function(function));
435 	}
436 
437 out:
438 	switch (step) {
439 	case PKCS11_FUNC_STEP_UPDATE:
440 		if (rc != PKCS11_CKR_OK && rc != PKCS11_CKR_BUFFER_TOO_SMALL)
441 			release_active_processing(session);
442 		break;
443 	default:
444 		/* ONESHOT and FINAL terminates processing on success */
445 		if (rc != PKCS11_CKR_BUFFER_TOO_SMALL)
446 			release_active_processing(session);
447 		break;
448 	}
449 
450 	return rc;
451 }
452