Add authentication attributes support to hp-bioscfg.
HP BIOS Configuration driver purpose is to provide a driver supporting
the latest sysfs class firmware attributes framework allowing the user
to change BIOS settings and security solutions on HP Inc.’s commercial
notebooks.
Signed-off-by: Jorge Lopez <jorge.lopez2@xxxxxx>
---
Based on the latest platform-drivers-x86.git/for-next
---
.../x86/hp/hp-bioscfg/passwdobj-attributes.c | 543 ++++++++++++++++++
1 file changed, 543 insertions(+)
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c
diff --git a/drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c b/drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c
new file mode 100644
index 000000000000..52e4d346b529
--- /dev/null
+++ b/drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c
@@ -0,0 +1,543 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions corresponding to password object type attributes under
+ * BIOS PASSWORD for use with hp-bioscfg driver.
+ *
+ * Copyright (c) 2022 HP Development Company, L.P.
+ */
+
+#include "bioscfg.h"
+#include <asm-generic/posix_types.h>
+
+GET_INSTANCE_ID(password);
+/*
+ * Clear all passwords copied to memory for a particular
+ * authentication instance
+ */
+static int clear_passwords(const int instance)
+{
+ struct password_data *password_data = &bioscfg_drv.password_data[instance];
+
+ if (!password_data->is_enabled)
+ return 0;
+
+ memset(password_data->current_password,
+ 0, sizeof(password_data->current_password));
+ memset(password_data->new_password,
+ 0, sizeof(password_data->new_password));
+
+ return 0;
+}
+
+/*
+ * Clear all credentials copied to memory for both Power-ON and Setup
+ * BIOS instances
+ */
+int hp_clear_all_credentials(void)
+{
+ int count = bioscfg_drv.password_instances_count;
+ int instance;
+
+ /* clear all passwords */
+ for (instance = 0; instance < count; instance++)
+ clear_passwords(instance);
+
+ /* clear auth_token */
+ kfree(bioscfg_drv.spm_data.auth_token);
+ bioscfg_drv.spm_data.auth_token = NULL;
+
+ return 0;
+}
+
+int hp_get_password_instance_for_type(const char *name)
+{
+ int count = bioscfg_drv.password_instances_count;
+ int instance;
+
+ for (instance = 0; instance < count; instance++)
+ if (!strcmp(bioscfg_drv.password_data[instance].common.display_name, name))
+ return instance;
+
+ return -EINVAL;
+}
+
+static int validate_password_input(int instance_id, const char *buf)
+{
+ int length;
+ struct password_data *password_data = &bioscfg_drv.password_data[instance_id];
+
+ length = strlen(buf);
+ if (buf[length - 1] == '\n')
+ length--;
+
+ if (length > MAX_PASSWD_SIZE)
+ return INVALID_BIOS_AUTH;
+
+ if (password_data->min_password_length > length ||
+ password_data->max_password_length < length)
+ return INVALID_BIOS_AUTH;
+ return SUCCESS;
+}
+
+ATTRIBUTE_N_PROPERTY_SHOW(is_enabled, password);
+static struct kobj_attribute password_is_password_set = __ATTR_RO(is_enabled);
+
+static int store_password_instance(struct kobject *kobj, const char *buf,
+ size_t count, bool is_current)
+{
+ char *buf_cp;
+ int id, ret = 0;
+
+ buf_cp = kstrdup(buf, GFP_KERNEL);
+ if (!buf_cp)
+ return -ENOMEM;
+
+ ret = hp_enforce_single_line_input(buf_cp, count);
+ if (!ret) {
+ id = get_password_instance_id(kobj);
+
+ if (id >= 0)
+ ret = validate_password_input(id, buf_cp);
+ }
+
+ if (!ret) {
+ if (is_current)
+ strscpy(bioscfg_drv.password_data[id].current_password,
+ buf_cp,
+ sizeof(bioscfg_drv.password_data[id].current_password));
+ else
+ strscpy(bioscfg_drv.password_data[id].new_password,
+ buf_cp,
+ sizeof(bioscfg_drv.password_data[id].new_password));
+ }
+
+ kfree(buf_cp);
+ return ret < 0 ? ret : count;
+}
+
+static ssize_t current_password_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ return store_password_instance(kobj, buf, count, true);
+}
+
+static struct kobj_attribute password_current_password = __ATTR_WO(current_password);
+
+static ssize_t new_password_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ return store_password_instance(kobj, buf, count, true);
+}
+
+static struct kobj_attribute password_new_password = __ATTR_WO(new_password);
+
+ATTRIBUTE_N_PROPERTY_SHOW(min_password_length, password);
+static struct kobj_attribute password_min_password_length = __ATTR_RO(min_password_length);
+
+ATTRIBUTE_N_PROPERTY_SHOW(max_password_length, password);
+static struct kobj_attribute password_max_password_length = __ATTR_RO(max_password_length);
+
+static ssize_t role_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+ if (!strcmp(kobj->name, SETUP_PASSWD))
+ return sysfs_emit(buf, "%s\n", BIOS_ADMIN);
+
+ if (!strcmp(kobj->name, POWER_ON_PASSWD))
+ return sysfs_emit(buf, "%s\n", POWER_ON);
+
+ return -EIO;
+}
+
+static struct kobj_attribute password_role = __ATTR_RO(role);
+
+static ssize_t mechanism_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ int i = get_password_instance_id(kobj);
+
+ if (i < 0)
+ return i;
+
+ if (bioscfg_drv.password_data[i].mechanism != PASSWORD)
+ return -EINVAL;
+
+ return sysfs_emit(buf, "%s\n", PASSWD_MECHANISM_TYPES);
+}
+
+static struct kobj_attribute password_mechanism = __ATTR_RO(mechanism);
+
+ATTRIBUTE_VALUES_PROPERTY_SHOW(encodings, password, SEMICOLON_SEP);
+static struct kobj_attribute password_encodings_val = __ATTR_RO(encodings);
+
+static struct attribute *password_attrs[] = {
+ &password_is_password_set.attr,
+ &password_min_password_length.attr,
+ &password_max_password_length.attr,
+ &password_current_password.attr,
+ &password_new_password.attr,
+ &password_role.attr,
+ &password_mechanism.attr,
+ &password_encodings_val.attr,
+ NULL
+};
+
+static const struct attribute_group password_attr_group = {
+ .attrs = password_attrs
+};
+
+int hp_alloc_password_data(void)
+{
+ bioscfg_drv.password_instances_count = hp_get_instance_count(HP_WMI_BIOS_PASSWORD_GUID);
+ bioscfg_drv.password_data = kcalloc(bioscfg_drv.password_instances_count,
+ sizeof(*bioscfg_drv.password_data), GFP_KERNEL);
+ if (!bioscfg_drv.password_data) {
+ bioscfg_drv.password_instances_count = 0;
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+/* Expected Values types associated with each element */
+static const acpi_object_type expected_password_types[] = {
+ [NAME] = ACPI_TYPE_STRING,
+ [VALUE] = ACPI_TYPE_STRING,
+ [PATH] = ACPI_TYPE_STRING,
+ [IS_READONLY] = ACPI_TYPE_INTEGER,
+ [DISPLAY_IN_UI] = ACPI_TYPE_INTEGER,
+ [REQUIRES_PHYSICAL_PRESENCE] = ACPI_TYPE_INTEGER,
+ [SEQUENCE] = ACPI_TYPE_INTEGER,
+ [PREREQUISITES_SIZE] = ACPI_TYPE_INTEGER,
+ [PREREQUISITES] = ACPI_TYPE_STRING,
+ [SECURITY_LEVEL] = ACPI_TYPE_INTEGER,
+ [PSWD_MIN_LENGTH] = ACPI_TYPE_INTEGER,
+ [PSWD_MAX_LENGTH] = ACPI_TYPE_INTEGER,
+ [PSWD_SIZE] = ACPI_TYPE_INTEGER,
+ [PSWD_ENCODINGS] = ACPI_TYPE_STRING,
+ [PSWD_IS_SET] = ACPI_TYPE_INTEGER,
+};
+
+static int hp_populate_password_elements_from_package(union acpi_object *password_obj,
+ int password_obj_count,
+ int instance_id)
+{
+ char *str_value = NULL;
+ int value_len;
+ int ret;
+ u32 size;
+ u32 int_value;
+ int elem;
+ int reqs;
+ int eloc;
+ int pos_values;
+ struct password_data *password_data = &bioscfg_drv.password_data[instance_id];
+
+ if (!password_obj)
+ return -EINVAL;
+
+ for (elem = 1, eloc = 1; elem < password_obj_count; elem++, eloc++) {
+ /* ONLY look at the first PASSWORD_ELEM_CNT elements */
+ if (eloc == PSWD_ELEM_CNT)
+ goto exit_package;
+
+ switch (password_obj[elem].type) {
+ case ACPI_TYPE_STRING:
+ if (PREREQUISITES != elem && PSWD_ENCODINGS != elem) {
+ ret = hp_convert_hexstr_to_str(password_obj[elem].string.pointer,
+ password_obj[elem].string.length,
+ &str_value, &value_len);
+ if (ret)
+ continue;
+ }
+ break;
+ case ACPI_TYPE_INTEGER:
+ int_value = (u32)password_obj[elem].integer.value;
+ break;
+ default:
+ pr_warn("Unsupported object type [%d]\n", password_obj[elem].type);
+ continue;
+ }
+
+ /* Check that both expected and read object type match */
+ if (expected_password_types[eloc] != password_obj[elem].type) {
+ pr_err("Error expected type %d for elem %d, but got type %d instead\n",
+ expected_password_types[eloc], elem, password_obj[elem].type);
+ return -EIO;
+ }
+
+ /* Assign appropriate element value to corresponding field*/
+ switch (eloc) {
+ case VALUE:
+ break;
+ case PATH:
+ strscpy(password_data->common.path, str_value,
+ sizeof(password_data->common.path));
+ break;
+ case IS_READONLY:
+ password_data->common.is_readonly = int_value;
+ break;
+ case DISPLAY_IN_UI:
+ password_data->common.display_in_ui = int_value;
+ break;
+ case REQUIRES_PHYSICAL_PRESENCE:
+ password_data->common.requires_physical_presence = int_value;
+ break;
+ case SEQUENCE:
+ password_data->common.sequence = int_value;
+ break;
+ case PREREQUISITES_SIZE:
+ password_data->common.prerequisites_size = int_value;
+ if (int_value > MAX_PREREQUISITES_SIZE)
+ pr_warn("Prerequisites size value exceeded the maximum number of elements supported or data may be malformed\n");
+
+ /* This HACK is needed to keep the expected
+ * element list pointing to the right obj[elem].type
+ * when the size is zero. PREREQUISITES
+ * object is omitted by BIOS when the size is
+ * zero.
+ */
+ if (int_value == 0)
+ eloc++;
+ break;
+ case PREREQUISITES:
+ size = min_t(u32, password_data->common.prerequisites_size,
+ MAX_PREREQUISITES_SIZE);
+
+ for (reqs = 0; reqs < size; reqs++) {
+ ret = hp_convert_hexstr_to_str(password_obj[elem + reqs].string.pointer,
+ password_obj[elem + reqs].string.length,
+ &str_value, &value_len);
+
+ if (ret)
+ break;
+
+ strscpy(password_data->common.prerequisites[reqs],
+ str_value,
+ sizeof(password_data->common.prerequisites[reqs]));
+
+ kfree(str_value);
+ }
+ break;
+ case SECURITY_LEVEL:
+ password_data->common.security_level = int_value;
+ break;
+ case PSWD_MIN_LENGTH:
+ password_data->min_password_length = int_value;
+ break;
+ case PSWD_MAX_LENGTH:
+ password_data->max_password_length = int_value;
+ break;
+ case PSWD_SIZE:
+ password_data->encodings_size = int_value;
+ if (int_value > MAX_ENCODINGS_SIZE)
+ pr_warn("Password Encoding size value exceeded the maximum number of elements supported or data may be malformed\n");
+
+ /* This HACK is needed to keep the expected
+ * element list pointing to the right obj[elem].type
+ * when the size is zero. PSWD_ENCODINGS
+ * object is omitted by BIOS when the size is
+ * zero.
+ */
+ if (int_value == 0)
+ eloc++;
+ break;
+ case PSWD_ENCODINGS:
+ size = min_t(u32, password_data->encodings_size, MAX_ENCODINGS_SIZE);
+ for (pos_values = 0; pos_values < size; pos_values++) {
+ ret = hp_convert_hexstr_to_str(password_obj[elem + pos_values].string.pointer,
+ password_obj[elem + pos_values].string.length,
+ &str_value, &value_len);
+ if (ret)
+ break;
+
+ strscpy(password_data->encodings[pos_values],
+ str_value,
+ sizeof(password_data->encodings[pos_values]));
+ kfree(str_value);
+ }
+ break;
+ case PSWD_IS_SET:
+ password_data->is_enabled = int_value;
+ break;
+ default:
+ pr_warn("Invalid element: %d found in Password attribute or data may be malformed\n", elem);
+ break;
+ }
+ }
+
+exit_package:
+ kfree(str_value);
+ return 0;
+}
+
+/**
+ * hp_populate_password_package_data()
+ * Populate all properties for an instance under password attribute
+ *
+ * @password_obj: ACPI object with password data
+ * @instance_id: The instance to enumerate
+ * @attr_name_kobj: The parent kernel object
+ */
+int hp_populate_password_package_data(union acpi_object *password_obj, int instance_id,
+ struct kobject *attr_name_kobj)
+{
+ struct password_data *password_data = &bioscfg_drv.password_data[instance_id];
+
+ password_data->attr_name_kobj = attr_name_kobj;
+
+ hp_populate_password_elements_from_package(password_obj,
+ password_obj->package.count,
+ instance_id);
+
+ hp_friendly_user_name_update(password_data->common.path,
+ attr_name_kobj->name,
+ password_data->common.display_name,
+ sizeof(password_data->common.display_name));
+
+ if (!strcmp(attr_name_kobj->name, SETUP_PASSWD))
+ return sysfs_create_group(attr_name_kobj, &password_attr_group);
+
+ return sysfs_create_group(attr_name_kobj, &password_attr_group);
+}
+
+static int hp_populate_password_elements_from_buffer(u8 *buffer_ptr, u32 *buffer_size,
+ int instance_id)
+{
+ int values;
+ int isreadonly;
+ struct password_data *password_data = &bioscfg_drv.password_data[instance_id];
+ int ret = 0;
+
+ /*
+ * Only data relevant to this driver and its functionality is
+ * read. BIOS defines the order in which each * element is
+ * read. Element 0 data is not relevant to this
+ * driver hence it is ignored. For clarity, all element names
+ * (DISPLAY_IN_UI) which defines the order in which is read
+ * and the name matches the variable where the data is stored.
+ *
+ * In earlier implementation, reported errors were ignored
+ * causing the data to remain uninitialized. It is not
+ * possible to determine if data read from BIOS is valid or
+ * not. It is for this reason functions may return a error
+ * without validating the data itself.
+ */
+
+ // VALUE:
+ ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size, password_data->current_password,
+ sizeof(password_data->current_password));
+ if (ret < 0)
+ goto buffer_exit;
+
+ // COMMON:
+ ret = hp_get_common_data_from_buffer(&buffer_ptr, buffer_size,
+ &password_data->common);
+ if (ret < 0)
+ goto buffer_exit;
+
+ // PSWD_MIN_LENGTH:
+ ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &password_data->min_password_length);
+ if (ret < 0)
+ goto buffer_exit;
+
+ // PSWD_MAX_LENGTH:
+ ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &password_data->max_password_length);
+ if (ret < 0)
+ goto buffer_exit;
+
+ // PSWD_SIZE:
+ ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &password_data->encodings_size);
+ if (ret < 0)
+ goto buffer_exit;
+
+ if (password_data->encodings_size > MAX_ENCODINGS_SIZE) {
+ /* Report a message and limit possible values size to maximum value */
+ pr_warn("Password Encoding size value exceeded the maximum number of elements supported or data may be malformed\n");
+ password_data->encodings_size = MAX_ENCODINGS_SIZE;
+ }
+
+ // PSWD_ENCODINGS:
+ for (values = 0; values < password_data->encodings_size; values++) {
+ ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size,
+ password_data->encodings[values],
+ sizeof(password_data->encodings[values]));
+ if (ret < 0)
+ break;
+ }
+
+ // PSWD_IS_SET:
+ ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size, &isreadonly);
+ if (ret < 0)
+ goto buffer_exit;
+
+ password_data->is_enabled = isreadonly ? true : false;
+
+buffer_exit:
+ return ret;
+}
+
+/**
+ * hp_populate_password_buffer_data()
+ * Populate all properties for an instance under password object attribute
+ *
+ * @buffer_ptr: Buffer pointer
+ * @buffer_size: Buffer size
+ * @instance_id: The instance to enumerate
+ * @attr_name_kobj: The parent kernel object
+ */
+int hp_populate_password_buffer_data(u8 *buffer_ptr, u32 *buffer_size, int instance_id,
+ struct kobject *attr_name_kobj)
+{
+ struct password_data *password_data = &bioscfg_drv.password_data[instance_id];
+ int ret = 0;
+
+ password_data->attr_name_kobj = attr_name_kobj;
+
+ /* Populate Password attributes */
+ ret = hp_populate_password_elements_from_buffer(buffer_ptr, buffer_size,
+ instance_id);
+ if (ret < 0)
+ return ret;
+
+ hp_friendly_user_name_update(password_data->common.path,
+ attr_name_kobj->name,
+ password_data->common.display_name,
+ sizeof(password_data->common.display_name));
+ if (!strcmp(attr_name_kobj->name, SETUP_PASSWD))
+ return sysfs_create_group(attr_name_kobj, &password_attr_group);
+
+ return sysfs_create_group(attr_name_kobj, &password_attr_group);
+}
+
+/**
+ * hp_exit_password_attributes() - Clear all attribute data
+ *
+ * Clears all data allocated for this group of attributes
+ */
+void hp_exit_password_attributes(void)
+{
+ int instance_id;
+
+ for (instance_id = 0; instance_id < bioscfg_drv.password_instances_count;
+ instance_id++) {
+ struct kobject *attr_name_kobj =
+ bioscfg_drv.password_data[instance_id].attr_name_kobj;
+
+ if (attr_name_kobj) {
+ if (!strcmp(attr_name_kobj->name, SETUP_PASSWD))
+ sysfs_remove_group(attr_name_kobj,
+ &password_attr_group);
+ else
+ sysfs_remove_group(attr_name_kobj,
+ &password_attr_group);
+ }
+ }
+ bioscfg_drv.password_instances_count = 0;
+ kfree(bioscfg_drv.password_data);
+ bioscfg_drv.password_data = NULL;
+}
--
2.34.1
