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

source code of linux/drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c