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(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(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,
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(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, 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, 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, "%s\n", BIOS_ADMIN);
145
146	if (!strcmp(kobj->name, POWER_ON_PASSWD))
147		return sysfs_emit(buf, "%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, "%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(bioscfg_drv.password_instances_count,
193					    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(password_obj[elem].string.pointer,
248							       password_obj[elem].string.length,
249							       &str_value, &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(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(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],
319					str_value,
320					sizeof(password_data->common.prerequisites[reqs]));
321
322				kfree(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(password_obj[elem + pos_values].string.pointer,
357							       password_obj[elem + pos_values].string.length,
358							       &str_value, &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(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(str_value);
379		str_value = NULL;
380	}
381
382exit_package:
383	kfree(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->package.count,
404						   instance_id);
405
406	hp_friendly_user_name_update(password_data->common.path,
407				     attr_name_kobj->name,
408				     password_data->common.display_name,
409				     sizeof(password_data->common.display_name));
410
411	if (!strcmp(attr_name_kobj->name, SETUP_PASSWD))
412		return sysfs_create_group(attr_name_kobj, &password_attr_group);
413
414	return sysfs_create_group(attr_name_kobj, &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_ptr, buffer_size, password_data->current_password,
442					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_size,
448					     &password_data->common);
449	if (ret < 0)
450		goto buffer_exit;
451
452	// PSWD_MIN_LENGTH:
453	ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
454					 &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_ptr, buffer_size,
460					 &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_ptr, buffer_size,
466					 &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_ptr, buffer_size,
479						password_data->encodings[values],
480						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_ptr, buffer_size, &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(password_data->common.path,
520				     attr_name_kobj->name,
521				     password_data->common.display_name,
522				     sizeof(password_data->common.display_name));
523	if (!strcmp(attr_name_kobj->name, SETUP_PASSWD))
524		return sysfs_create_group(attr_name_kobj, &password_attr_group);
525
526	return sysfs_create_group(attr_name_kobj, &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(attr_name_kobj,
546						   &password_attr_group);
547			else
548				sysfs_remove_group(attr_name_kobj,
549						   &password_attr_group);
550		}
551	}
552	bioscfg_drv.password_instances_count = 0;
553	kfree(bioscfg_drv.password_data);
554	bioscfg_drv.password_data = NULL;
555}
556