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