1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Functions corresponding to password object type attributes under
4  * BIOS PASSWORD for use with hp-bioscfg driver.
5  *
6  * Copyright (c) 2022 HP Development Company, L.P.
7  */
8 
9 #include "bioscfg.h"
10 #include <asm-generic/posix_types.h>
11 
12 GET_INSTANCE_ID(password);
13 /*
14  * Clear all passwords copied to memory for a particular
15  * authentication instance
16  */
clear_passwords(const int instance)17 static int clear_passwords(const int instance)
18 {
19 	struct password_data *password_data = &bioscfg_drv.password_data[instance];
20 
21 	if (!password_data->is_enabled)
22 		return 0;
23 
24 	memset(password_data->current_password,
25 	       0, sizeof(password_data->current_password));
26 	memset(password_data->new_password,
27 	       0, sizeof(password_data->new_password));
28 
29 	return 0;
30 }
31 
32 /*
33  * Clear all credentials copied to memory for both Power-ON and Setup
34  * BIOS instances
35  */
hp_clear_all_credentials(void)36 int hp_clear_all_credentials(void)
37 {
38 	int count = bioscfg_drv.password_instances_count;
39 	int instance;
40 
41 	/* clear all passwords */
42 	for (instance = 0; instance < count; instance++)
43 		clear_passwords(instance);
44 
45 	/* clear auth_token */
46 	kfree(bioscfg_drv.spm_data.auth_token);
47 	bioscfg_drv.spm_data.auth_token = NULL;
48 
49 	return 0;
50 }
51 
hp_get_password_instance_for_type(const char * name)52 int hp_get_password_instance_for_type(const char *name)
53 {
54 	int count = bioscfg_drv.password_instances_count;
55 	int instance;
56 
57 	for (instance = 0; instance < count; instance++)
58 		if (!strcmp(bioscfg_drv.password_data[instance].common.display_name, name))
59 			return instance;
60 
61 	return -EINVAL;
62 }
63 
validate_password_input(int instance_id,const char * buf)64 static int validate_password_input(int instance_id, const char *buf)
65 {
66 	int length;
67 	struct password_data *password_data = &bioscfg_drv.password_data[instance_id];
68 
69 	length = strlen(buf);
70 	if (buf[length - 1] == '\n')
71 		length--;
72 
73 	if (length > MAX_PASSWD_SIZE)
74 		return INVALID_BIOS_AUTH;
75 
76 	if (password_data->min_password_length > length ||
77 	    password_data->max_password_length < length)
78 		return INVALID_BIOS_AUTH;
79 	return SUCCESS;
80 }
81 
82 ATTRIBUTE_N_PROPERTY_SHOW(is_enabled, password);
83 static struct kobj_attribute password_is_password_set = __ATTR_RO(is_enabled);
84 
store_password_instance(struct kobject * kobj,const char * buf,size_t count,bool is_current)85 static int store_password_instance(struct kobject *kobj, const char *buf,
86 				   size_t count, bool is_current)
87 {
88 	char *buf_cp;
89 	int id, ret = 0;
90 
91 	buf_cp = kstrdup(buf, GFP_KERNEL);
92 	if (!buf_cp)
93 		return -ENOMEM;
94 
95 	ret = hp_enforce_single_line_input(buf_cp, count);
96 	if (!ret) {
97 		id = get_password_instance_id(kobj);
98 
99 		if (id >= 0)
100 			ret = validate_password_input(id, buf_cp);
101 	}
102 
103 	if (!ret) {
104 		if (is_current)
105 			strscpy(bioscfg_drv.password_data[id].current_password,
106 				buf_cp,
107 				sizeof(bioscfg_drv.password_data[id].current_password));
108 		else
109 			strscpy(bioscfg_drv.password_data[id].new_password,
110 				buf_cp,
111 				sizeof(bioscfg_drv.password_data[id].new_password));
112 	}
113 
114 	kfree(buf_cp);
115 	return ret < 0 ? ret : count;
116 }
117 
current_password_store(struct kobject * kobj,struct kobj_attribute * attr,const char * buf,size_t count)118 static ssize_t current_password_store(struct kobject *kobj,
119 				      struct kobj_attribute *attr,
120 				      const char *buf, size_t count)
121 {
122 	return store_password_instance(kobj, buf, count, true);
123 }
124 
125 static struct kobj_attribute password_current_password = __ATTR_WO(current_password);
126 
new_password_store(struct kobject * kobj,struct kobj_attribute * attr,const char * buf,size_t count)127 static ssize_t new_password_store(struct kobject *kobj,
128 				  struct kobj_attribute *attr,
129 				  const char *buf, size_t count)
130 {
131 	return store_password_instance(kobj, buf, count, true);
132 }
133 
134 static struct kobj_attribute password_new_password = __ATTR_WO(new_password);
135 
136 ATTRIBUTE_N_PROPERTY_SHOW(min_password_length, password);
137 static struct kobj_attribute password_min_password_length = __ATTR_RO(min_password_length);
138 
139 ATTRIBUTE_N_PROPERTY_SHOW(max_password_length, password);
140 static struct kobj_attribute password_max_password_length = __ATTR_RO(max_password_length);
141 
role_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)142 static ssize_t role_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
143 {
144 	if (!strcmp(kobj->name, SETUP_PASSWD))
145 		return sysfs_emit(buf, "%s\n", BIOS_ADMIN);
146 
147 	if (!strcmp(kobj->name, POWER_ON_PASSWD))
148 		return sysfs_emit(buf, "%s\n", POWER_ON);
149 
150 	return -EIO;
151 }
152 
153 static struct kobj_attribute password_role = __ATTR_RO(role);
154 
mechanism_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)155 static ssize_t mechanism_show(struct kobject *kobj, struct kobj_attribute *attr,
156 			      char *buf)
157 {
158 	int i = get_password_instance_id(kobj);
159 
160 	if (i < 0)
161 		return i;
162 
163 	if (bioscfg_drv.password_data[i].mechanism != PASSWORD)
164 		return -EINVAL;
165 
166 	return sysfs_emit(buf, "%s\n", PASSWD_MECHANISM_TYPES);
167 }
168 
169 static struct kobj_attribute password_mechanism = __ATTR_RO(mechanism);
170 
171 ATTRIBUTE_VALUES_PROPERTY_SHOW(encodings, password, SEMICOLON_SEP);
172 static struct kobj_attribute password_encodings_val = __ATTR_RO(encodings);
173 
174 static struct attribute *password_attrs[] = {
175 	&password_is_password_set.attr,
176 	&password_min_password_length.attr,
177 	&password_max_password_length.attr,
178 	&password_current_password.attr,
179 	&password_new_password.attr,
180 	&password_role.attr,
181 	&password_mechanism.attr,
182 	&password_encodings_val.attr,
183 	NULL
184 };
185 
186 static const struct attribute_group password_attr_group = {
187 	.attrs = password_attrs
188 };
189 
hp_alloc_password_data(void)190 int hp_alloc_password_data(void)
191 {
192 	bioscfg_drv.password_instances_count = hp_get_instance_count(HP_WMI_BIOS_PASSWORD_GUID);
193 	bioscfg_drv.password_data = kcalloc(bioscfg_drv.password_instances_count,
194 					    sizeof(*bioscfg_drv.password_data), GFP_KERNEL);
195 	if (!bioscfg_drv.password_data) {
196 		bioscfg_drv.password_instances_count = 0;
197 		return -ENOMEM;
198 	}
199 
200 	return 0;
201 }
202 
203 /* Expected Values types associated with each element */
204 static const acpi_object_type expected_password_types[] = {
205 	[NAME] = ACPI_TYPE_STRING,
206 	[VALUE] = ACPI_TYPE_STRING,
207 	[PATH] = ACPI_TYPE_STRING,
208 	[IS_READONLY] = ACPI_TYPE_INTEGER,
209 	[DISPLAY_IN_UI] = ACPI_TYPE_INTEGER,
210 	[REQUIRES_PHYSICAL_PRESENCE] = ACPI_TYPE_INTEGER,
211 	[SEQUENCE] = ACPI_TYPE_INTEGER,
212 	[PREREQUISITES_SIZE] = ACPI_TYPE_INTEGER,
213 	[PREREQUISITES] = ACPI_TYPE_STRING,
214 	[SECURITY_LEVEL] = ACPI_TYPE_INTEGER,
215 	[PSWD_MIN_LENGTH] = ACPI_TYPE_INTEGER,
216 	[PSWD_MAX_LENGTH] = ACPI_TYPE_INTEGER,
217 	[PSWD_SIZE] = ACPI_TYPE_INTEGER,
218 	[PSWD_ENCODINGS] = ACPI_TYPE_STRING,
219 	[PSWD_IS_SET] = ACPI_TYPE_INTEGER,
220 };
221 
hp_populate_password_elements_from_package(union acpi_object * password_obj,int password_obj_count,int instance_id)222 static int hp_populate_password_elements_from_package(union acpi_object *password_obj,
223 						      int password_obj_count,
224 						      int instance_id)
225 {
226 	char *str_value = NULL;
227 	int value_len;
228 	int ret;
229 	u32 size;
230 	u32 int_value = 0;
231 	int elem;
232 	int reqs;
233 	int eloc;
234 	int pos_values;
235 	struct password_data *password_data = &bioscfg_drv.password_data[instance_id];
236 
237 	if (!password_obj)
238 		return -EINVAL;
239 
240 	for (elem = 1, eloc = 1; elem < password_obj_count; elem++, eloc++) {
241 		/* ONLY look at the first PASSWORD_ELEM_CNT elements */
242 		if (eloc == PSWD_ELEM_CNT)
243 			goto exit_package;
244 
245 		switch (password_obj[elem].type) {
246 		case ACPI_TYPE_STRING:
247 			if (PREREQUISITES != elem && PSWD_ENCODINGS != elem) {
248 				ret = hp_convert_hexstr_to_str(password_obj[elem].string.pointer,
249 							       password_obj[elem].string.length,
250 							       &str_value, &value_len);
251 				if (ret)
252 					continue;
253 			}
254 			break;
255 		case ACPI_TYPE_INTEGER:
256 			int_value = (u32)password_obj[elem].integer.value;
257 			break;
258 		default:
259 			pr_warn("Unsupported object type [%d]\n", password_obj[elem].type);
260 			continue;
261 		}
262 
263 		/* Check that both expected and read object type match */
264 		if (expected_password_types[eloc] != password_obj[elem].type) {
265 			pr_err("Error expected type %d for elem %d, but got type %d instead\n",
266 			       expected_password_types[eloc], elem, password_obj[elem].type);
267 			kfree(str_value);
268 			return -EIO;
269 		}
270 
271 		/* Assign appropriate element value to corresponding field*/
272 		switch (eloc) {
273 		case VALUE:
274 			break;
275 		case PATH:
276 			strscpy(password_data->common.path, str_value,
277 				sizeof(password_data->common.path));
278 			break;
279 		case IS_READONLY:
280 			password_data->common.is_readonly = int_value;
281 			break;
282 		case DISPLAY_IN_UI:
283 			password_data->common.display_in_ui = int_value;
284 			break;
285 		case REQUIRES_PHYSICAL_PRESENCE:
286 			password_data->common.requires_physical_presence = int_value;
287 			break;
288 		case SEQUENCE:
289 			password_data->common.sequence = int_value;
290 			break;
291 		case PREREQUISITES_SIZE:
292 			if (int_value > MAX_PREREQUISITES_SIZE) {
293 				pr_warn("Prerequisites size value exceeded the maximum number of elements supported or data may be malformed\n");
294 				int_value = MAX_PREREQUISITES_SIZE;
295 			}
296 			password_data->common.prerequisites_size = int_value;
297 
298 			/* This step is needed to keep the expected
299 			 * element list pointing to the right obj[elem].type
300 			 * when the size is zero. PREREQUISITES
301 			 * object is omitted by BIOS when the size is
302 			 * zero.
303 			 */
304 			if (int_value == 0)
305 				eloc++;
306 			break;
307 		case PREREQUISITES:
308 			size = min_t(u32, password_data->common.prerequisites_size,
309 				     MAX_PREREQUISITES_SIZE);
310 
311 			for (reqs = 0; reqs < size; reqs++) {
312 				ret = hp_convert_hexstr_to_str(password_obj[elem + reqs].string.pointer,
313 							       password_obj[elem + reqs].string.length,
314 							       &str_value, &value_len);
315 
316 				if (ret)
317 					break;
318 
319 				strscpy(password_data->common.prerequisites[reqs],
320 					str_value,
321 					sizeof(password_data->common.prerequisites[reqs]));
322 
323 				kfree(str_value);
324 				str_value = NULL;
325 
326 			}
327 			break;
328 		case SECURITY_LEVEL:
329 			password_data->common.security_level = int_value;
330 			break;
331 		case PSWD_MIN_LENGTH:
332 			password_data->min_password_length = int_value;
333 			break;
334 		case PSWD_MAX_LENGTH:
335 			password_data->max_password_length = int_value;
336 			break;
337 		case PSWD_SIZE:
338 
339 			if (int_value > MAX_ENCODINGS_SIZE) {
340 				pr_warn("Password Encoding size value exceeded the maximum number of elements supported or data may be malformed\n");
341 				int_value = MAX_ENCODINGS_SIZE;
342 			}
343 			password_data->encodings_size = int_value;
344 
345 			/* This step is needed to keep the expected
346 			 * element list pointing to the right obj[elem].type
347 			 * when the size is zero. PSWD_ENCODINGS
348 			 * object is omitted by BIOS when the size is
349 			 * zero.
350 			 */
351 			if (int_value == 0)
352 				eloc++;
353 			break;
354 		case PSWD_ENCODINGS:
355 			size = min_t(u32, password_data->encodings_size, MAX_ENCODINGS_SIZE);
356 			for (pos_values = 0; pos_values < size; pos_values++) {
357 				ret = hp_convert_hexstr_to_str(password_obj[elem + pos_values].string.pointer,
358 							       password_obj[elem + pos_values].string.length,
359 							       &str_value, &value_len);
360 				if (ret)
361 					break;
362 
363 				strscpy(password_data->encodings[pos_values],
364 					str_value,
365 					sizeof(password_data->encodings[pos_values]));
366 				kfree(str_value);
367 				str_value = NULL;
368 
369 			}
370 			break;
371 		case PSWD_IS_SET:
372 			password_data->is_enabled = int_value;
373 			break;
374 		default:
375 			pr_warn("Invalid element: %d found in Password attribute or data may be malformed\n", elem);
376 			break;
377 		}
378 
379 		kfree(str_value);
380 		str_value = NULL;
381 	}
382 
383 exit_package:
384 	kfree(str_value);
385 	return 0;
386 }
387 
388 /**
389  * hp_populate_password_package_data()
390  *	Populate all properties for an instance under password attribute
391  *
392  * @password_obj: ACPI object with password data
393  * @instance_id: The instance to enumerate
394  * @attr_name_kobj: The parent kernel object
395  */
hp_populate_password_package_data(union acpi_object * password_obj,int instance_id,struct kobject * attr_name_kobj)396 int hp_populate_password_package_data(union acpi_object *password_obj, int instance_id,
397 				      struct kobject *attr_name_kobj)
398 {
399 	struct password_data *password_data = &bioscfg_drv.password_data[instance_id];
400 
401 	password_data->attr_name_kobj = attr_name_kobj;
402 
403 	hp_populate_password_elements_from_package(password_obj,
404 						   password_obj->package.count,
405 						   instance_id);
406 
407 	hp_friendly_user_name_update(password_data->common.path,
408 				     attr_name_kobj->name,
409 				     password_data->common.display_name,
410 				     sizeof(password_data->common.display_name));
411 
412 	if (!strcmp(attr_name_kobj->name, SETUP_PASSWD))
413 		return sysfs_create_group(attr_name_kobj, &password_attr_group);
414 
415 	return sysfs_create_group(attr_name_kobj, &password_attr_group);
416 }
417 
hp_populate_password_elements_from_buffer(u8 * buffer_ptr,u32 * buffer_size,int instance_id)418 static int hp_populate_password_elements_from_buffer(u8 *buffer_ptr, u32 *buffer_size,
419 						     int instance_id)
420 {
421 	int values;
422 	int isreadonly;
423 	struct password_data *password_data = &bioscfg_drv.password_data[instance_id];
424 	int ret = 0;
425 
426 	/*
427 	 * Only data relevant to this driver and its functionality is
428 	 * read. BIOS defines the order in which each * element is
429 	 * read. Element 0 data is not relevant to this
430 	 * driver hence it is ignored. For clarity, all element names
431 	 * (DISPLAY_IN_UI) which defines the order in which is read
432 	 * and the name matches the variable where the data is stored.
433 	 *
434 	 * In earlier implementation, reported errors were ignored
435 	 * causing the data to remain uninitialized. It is not
436 	 * possible to determine if data read from BIOS is valid or
437 	 * not. It is for this reason functions may return a error
438 	 * without validating the data itself.
439 	 */
440 
441 	// VALUE:
442 	ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size, password_data->current_password,
443 					sizeof(password_data->current_password));
444 	if (ret < 0)
445 		goto buffer_exit;
446 
447 	// COMMON:
448 	ret = hp_get_common_data_from_buffer(&buffer_ptr, buffer_size,
449 					     &password_data->common);
450 	if (ret < 0)
451 		goto buffer_exit;
452 
453 	// PSWD_MIN_LENGTH:
454 	ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
455 					 &password_data->min_password_length);
456 	if (ret < 0)
457 		goto buffer_exit;
458 
459 	// PSWD_MAX_LENGTH:
460 	ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
461 					 &password_data->max_password_length);
462 	if (ret < 0)
463 		goto buffer_exit;
464 
465 	// PSWD_SIZE:
466 	ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
467 					 &password_data->encodings_size);
468 	if (ret < 0)
469 		goto buffer_exit;
470 
471 	if (password_data->encodings_size > MAX_ENCODINGS_SIZE) {
472 		/* Report a message and limit possible values size to maximum value */
473 		pr_warn("Password Encoding size value exceeded the maximum number of elements supported or data may be malformed\n");
474 		password_data->encodings_size = MAX_ENCODINGS_SIZE;
475 	}
476 
477 	// PSWD_ENCODINGS:
478 	for (values = 0; values < password_data->encodings_size; values++) {
479 		ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size,
480 						password_data->encodings[values],
481 						sizeof(password_data->encodings[values]));
482 		if (ret < 0)
483 			break;
484 	}
485 
486 	// PSWD_IS_SET:
487 	ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size, &isreadonly);
488 	if (ret < 0)
489 		goto buffer_exit;
490 
491 	password_data->is_enabled = isreadonly ? true : false;
492 
493 buffer_exit:
494 	return ret;
495 }
496 
497 /**
498  * hp_populate_password_buffer_data()
499  * Populate all properties for an instance under password object attribute
500  *
501  * @buffer_ptr: Buffer pointer
502  * @buffer_size: Buffer size
503  * @instance_id: The instance to enumerate
504  * @attr_name_kobj: The parent kernel object
505  */
hp_populate_password_buffer_data(u8 * buffer_ptr,u32 * buffer_size,int instance_id,struct kobject * attr_name_kobj)506 int hp_populate_password_buffer_data(u8 *buffer_ptr, u32 *buffer_size, int instance_id,
507 				     struct kobject *attr_name_kobj)
508 {
509 	struct password_data *password_data = &bioscfg_drv.password_data[instance_id];
510 	int ret = 0;
511 
512 	password_data->attr_name_kobj = attr_name_kobj;
513 
514 	/* Populate Password attributes */
515 	ret = hp_populate_password_elements_from_buffer(buffer_ptr, buffer_size,
516 							instance_id);
517 	if (ret < 0)
518 		return ret;
519 
520 	hp_friendly_user_name_update(password_data->common.path,
521 				     attr_name_kobj->name,
522 				     password_data->common.display_name,
523 				     sizeof(password_data->common.display_name));
524 	if (!strcmp(attr_name_kobj->name, SETUP_PASSWD))
525 		return sysfs_create_group(attr_name_kobj, &password_attr_group);
526 
527 	return sysfs_create_group(attr_name_kobj, &password_attr_group);
528 }
529 
530 /**
531  * hp_exit_password_attributes() - Clear all attribute data
532  *
533  * Clears all data allocated for this group of attributes
534  */
hp_exit_password_attributes(void)535 void hp_exit_password_attributes(void)
536 {
537 	int instance_id;
538 
539 	for (instance_id = 0; instance_id < bioscfg_drv.password_instances_count;
540 	     instance_id++) {
541 		struct kobject *attr_name_kobj =
542 			bioscfg_drv.password_data[instance_id].attr_name_kobj;
543 
544 		if (attr_name_kobj) {
545 			if (!strcmp(attr_name_kobj->name, SETUP_PASSWD))
546 				sysfs_remove_group(attr_name_kobj,
547 						   &password_attr_group);
548 			else
549 				sysfs_remove_group(attr_name_kobj,
550 						   &password_attr_group);
551 		}
552 	}
553 	bioscfg_drv.password_instances_count = 0;
554 	kfree(bioscfg_drv.password_data);
555 	bioscfg_drv.password_data = NULL;
556 }
557