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