36. User Identification

36.1. User Identification Overview

This section describes services which describe the current user of the platform. A user is the entity which is controlling the behavior of the machine. The user may be an individual, a class or group of individuals or another machine.

Each user has a user profile. There is always at least one user profile for a machine. This profile governs the behavior of the user identification process until another user has been selected. The nature and definition of these privileges are beyond the scope of this section. One user profile is always active and describes the platform’s current user.

New user profiles are introduced into the system through enrollment. During enrollment, information about a new user is gathered. Some of this information identifies the user for specific purposes, such as a user’s name or a user’s network domain. Other information is gathered in the form of credentials, which is information which can be used at a later time to verify the identity of a user. Credentials are generally divided into three categories: something you know (password), something you have (smart card, smart token, RFID), something you are (fingerprint). The means by which a platform determines the user’s identity based on credentials is user identification.

In the simplest case, a single set of credentials are required to establish a user’s identity. This is called single-factor authentication. In more rigorous cases, multiple credentials might be required to establish a user’s identity or different privilege levels given if only a single factor is available. This is called multi-factor authentication.

If the credentials are checked only once, this is called static authentication. For example, a sign-on box where the user enters a password and provides a fingerprint would be examples of static authentication. However, if credentials (and thus the user’s identity) can be changed during system execution, this is called dynamic authentication. For example, a smart token which can be hot-removed from the system or an RFID tag which is moved in and out of range would be examples of dynamic authentication.

The user identity manager is the optional UEFI driver which manages the process of determining the user’s identity and storing information about the user.

The user enrollment manager is the optional application which adds or enrolls new users, gathering the necessary information to ascertain their identity in the future.

The credential provider driver manages a single class of credentials. Examples include a USB fingerprint sensor, a smart card or a password. The means by which these drivers are selected and invoked is beyond the scope of this specification.

36.1.1. User Identify

The process of identifying the user occurs after platform initialization has made the services described in the EFI System Table available. Before the Boot Manager behavior described in chapter 3, a user profile must be established. The user profile established might be:

A default user profile, giving a standard set of privileges. This is similar to a “guest” login.
A default user profile, based on a User Credential Provider where Default() returns AutoLogon = TRUE.
A specific user profile, established using the Identify() function of the User Manager.

Every time the user profile is modified, the User Identity Manager will signal the EFI_EVENT_GROUP_USER_PROFILE_CHANGED event. The current user profile can only be changed by calling the User Identity Manager’s Identify() function or as the result of a credential provider calling the Notify() function (when dynamic authentication is supported). The Identify() function changes the current user profile after examining the credentials provided by the various credential providers and comparing these against those found in the user profile database.

_images/User_Identification-2.png — Fig. 36.1 User Identity

When the UEFI Boot Manager signals the EFI_EVENT_GROUP_READY_TO_BOOT event group, the User Identity Manager publishes the current user profile information in the EFI System Configuration Table.

Depending on the security considerations in the implementation (see Security Considerations ), user identification can continue into different phases of execution.

Boot Manager, Once. In this scenario, identification is permitted until the EFI_EVENT_GROUP_READY_TO_BOOT is signaled by the Boot Manager. After this time, user identification is not allowed again. This is the simplest, since the user profile database can be locked at this time using a simple one-time lock.
Boot Manager, Multiple. In this scenario, identification is permitted until the EFI_EVENT_GROUP_READY_TO_BOOT is signaled by the Boot Manager. After this time, if the boot option returns back into the Boot Manager, identification is allowed again. This scenario requires that the user profile database only be updatable while in the Boot Manager.
Until ExitBootServices. In this scenario, identification is permitted until the EFI_EVENT_GROUP_EXIT_BOOT_SERVICES is signaled by the Boot Manager. This scenario requires that the user profile database cannot be updated by unauthorized executables.

36.1.2. User Profiles

The user profiles are collections of information about users. There is always a current user (and thus, a currently selected user profile). The user profiles are stored in a user profile database.

Each user profile has the following attributes:

§ User Identifier

User identifiers are unique to a particular user profile. The uniqueness of the user profile identifier must persist across reboots. Credentials return this identifier during the identification process.

§ User Identification Policy

The user identification policy determines which credentials must be presented in order to establish the user’s identity and set the user profile as the current user profile. The policy consists of a boolean expression consisting of credential handles and the operators AND, OR and NOT. This allows the user profile to be selected, for example, depending on a password credential OR a fingerprint credential. Or the profile might be selected depending on a password credential AND a fingerprint credential.

§ User Privileges

The user privileges control what the user can and cannot do. For example, can the user enroll other users, boot off of a selected device, etc.

§ User Information

User information consists of typed data records attached to the user profile handle. Some of this information is non-volatile. Some of this information may be provided by a specific credential driver. User information is classified as public, private or protected:

Public user information is available at any time.
Private user information is only available while it is part of the current user profile.
Protected user information is only available once user has been authenticated by a credential provider.

Drivers and applications can be notified when the current user profile is changed, by using the UEFI Boot Service CreateEventEx() and the EFI_EVENT_GROUP_USER_PROFILE_CHANGED

User profiles are available while the User Identity Manager is running, but only the current user profile is available after the UEFI Boot Manager has started execution.

36.1.2.1. User Profile Database

The user profile database is a repository of all users known to the user identity manager. The user profile database should be maintained in non-volatile memory and this memory must be protected against corruption and erasure.

The user profile database is considered “open” if the user profile database can still be updated and the current profile can still be changed using the EFI User Manager Protocol. The user profile database is considered “closed” if the user profile database cannot be updated nor the current user profile changes using the EFI User Manager Protocol.

36.1.2.2. User Identification Policy

The user identification policy is a boolean expression which determines which class of credential or which credential providers must assert the user’s identity in order to a user profile to be eligible for selection as the current user profile.

For example, assume that you want a password:

CredentialClass(Password)

This expression would assert TRUE if any credential provider asserts that a user has successfully entered a password.

CredentialClass(Password) && CredentialClass(Fingerprint)

This expression would require the user to present both a fingerprint AND a password in order to select this user profile.

CredentialClass(Password) || CredentialClass(Fingerprint)

This expression, on the other hand, allows the user to present a fingerprint OR a password in order to select this user profile.

Let’s say you only want the Phoenix password provider:

CredentialClass(Password) && CredentialProvider(Phoenix)

In all of these cases, the class of credential and the provider of the credential are actually GUIDs. The standard credential class GUIDs are assigned by this specification. The credential provider identifiers are generated by the companies creating the credential providers.

36.1.3. Credential Providers

The User Credential Provider drivers follow the UEFI driver model. During initialization, they install an instance of the EFI Driver Binding Protocol. For hardware devices, the User Credential Provider may consume the bus I/O protocol and produce the User Credential Protocol. For software-based User Credential Providers, the User Credential Protocol could be installed on the image handler. The exact implementation depends on the number of separate credential types that the User Identity Manager will display.

When Start() is called, they:

Install one instance of the EFI_USER_CREDENTIAL2_PROTOCOL for each simultaneous user which might be authenticated. For example, if more than one smart token were inserted, then one instance might be created for each token. However, for a fingerprint sensor, one instance might be created for all fingerprint sensors managed by the same driver.
Install the user-interface forms used for interacting with the user using the HII Database Protocol. The form must be encoded using the GUID EFI_USER_CREDENTIAL2_PROTOCOL_GUID.
Install the EFI HII Configuration Access Protocol to handle interaction with the UEFI forms browser. This protocol is called to retrieve the current information from the credential provider. It is also called when the user presses OK to save the current form values. It also provides the callback functionality which allows real-time processing of the form values.

User Credential Providers are responsible to creating a one-to-one mapping between a device, fingerprint or password and a user identifier.

This specification does not explicitly support passing of user credential information related to operating system logon to an OS-present environment. For example, User Credential Providers may encrypt the user credential information and pass it, either as a part of the User Information Table or the EFI System Configuration Table, to an OS-present driver or application.

This specification does not explicitly support OS-present update of user credential information or user identification policy. Such support may be implemented in many ways, including the usage of write-authenticated EFI variables (see SetVariable() ) or capsules (see UpdateCapsule() ).

36.1.4. Security Considerations

Since the current profile details a number of security-related privileges, it is important that the User Identity Manager and User Credential Providers and the environment in which they execute are trusted.

This includes:

Protecting the storage area where these drivers are stored
Protecting the means by which these drivers are selected.
Protecting the execution environment of these drivers from unverified drivers.
The data structures used by these drivers should not be corrupted by unauthorized drivers while they are still being used.

_images/User_Identification-3.png — Fig. 36.2 User Identity Manager

In many cases, the User Identity Manager, the User Credential drivers and the on-board drivers are located in a protected location (e.g. a write-protected flash device) and the platform policy for these locations allows them to be trusted.

However, other drivers may be loaded from unprotected location or may be loaded from devices (such as PCI cards) or a hard drive which are easily replaced. Therefore, all drivers loaded prior to the User Identity Manager should be verified. No unverified drivers or applications should be allowed to execute while decisions based on the current user policy are still being made.

For example, either the default platform policy must successfully be able to verify drivers listed in the Driver#### load options, or else the user must be identified prior to processing these drivers. Otherwise, the drivers’ execution should be deferred. If the user profile is changed through a subsequent call to Identify() or through dynamic authentication, the Driver#### options may not be processed again.

In systems where the user profile database and current user profile can be protected from corruption, the user profile database is closed when the system signals the event EFI EXIT_BOOT_SERVICES_EVENT_GUID. In systems where the user profile database and current user profile cannot be protected from corruption, the user profile database is closed when the system signals the event EFI_READY_TO_BOOT_EVENT_GUID.

36.1.5. Deferred Execution

The platform may need to defer the execution of an image because of security considerations. For example, see LoadImage(). Information about the images which are not executed because of security considerations may be recorded and then reported by installing an instance of the EFI_DEFERRED_IMAGE_LOAD_PROTOCOL (see Deferred Image Load Protocol ). There may be more than one producer of the protocol.

The firmware’s boot manager may use the instances of this protocol in order to automatically load drivers whose execution was deferred because of inadequate privileges once the current user profile contains adequate security privileges.

This boot manager can reevaluate the deferred images each time that the event EFI_EVENT_GROUP_USER_IDENTITY_CHANGED is signaled

Images which have been loaded may not be unloaded when the current user profile is changed, even if the new user profile would have prevented that driver from being loaded.

36.2. User Identification Process

This section describes the typical initialization steps required for the user identification process.

36.2.1. User Identification Process

The User Identity Manager is launched. This driver reads all of the user profiles from the user profile database, sets the default user profile as the current profile, and installs an instance of the EFI_USER_MANAGER_PROTOCOL.
Each credential provider driver registers their user-interface related forms and installs an instance of the EFI_USER_CREDENTIAL2_PROTOCOL.
The User Identity Manager’s Identify() function is called to select the current user.
The User Identity Manager enumerates all of the User Credential Providers required by the User Identification Policy.

a. Select the User Credential Provider which returns Default = TRUE from the Default() function. If more than one return TRUE or none return TRUE, choose a default based on implementation-specific criteria (last-logged-on, etc.)

b. If that credential provider also returns AutoLogon = TRUE from the Default() function, then call User(). If no error was returned and a user profile with the specified user identifier exists, select the specified user profile as the current user profile and jump to step 9.

The User Identity Manager enumerates all of the User Credential Providers required by the User Identification Policy:

a. Call the Title() and (optionally) the Tile() function to retrieve the text and image indicated for each User Credential Provider.

b. Call the Form() function to retrieve the form indicated for each User Credential Provider.

c. Create the user interface to allow the user to select between the different User Credential Providers.

d. Highlight the default User Credential Provider, as specified in step 4.a.
If the user selects one of the User Credential Providers, call Select(). If AutoLogon = TRUE on return, then call User(). If no error was returned and a user profile with the specified user identifier exists, select the specified user profile as the current user profile and jump to step 9.
Interact with the user. Regular interaction can occur using the Callback() functions. If another User Credential Provider is selected then Deselect() is called for the current User Credential Provider and Select() is called for the newly selected User Credential Provider.
If the user presses OK then the User Manager will saved settings using the EFI Configuration Access protocol. Then it will call the User() function of each credential provider. If it returns successfully and one of the user policies evaluates to TRUE, then select the specified user profile as the current user profile and go to step 9. Otherwise display an error and go back.
Go through all of the credential providers using GetNextInfo() and GetInfo() and add the information to the current user profile.
Exit

36.2.2. Changing The Current User Profile

This section describes the typical actions taken when the current user profile is changed.

If there was already a valid current user profile, then all records marked as private in that profile are no longer available.
All records marked as private in the new user profile will be available.
The handle of the current user profile is changed.
An event with the GUID EFI_EVENT_GROUP_USER_IDENTITY_CHANGED is signaled to indicate that the current user profile has been changed.

36.2.3. Ready To Boot

Before the boot manager is read to pass control to the boot option and signals the EFI_EVENT_GROUP_READY_TO_BOOT event group, the User Identity Manager will publish the current user profile into the EFI System Configuration Table with the EFI_USER_MANAGER_PROTOCOL_GUID. The format is described in the User Information Table (User Information Table). It will also save all non-volatile profile information.

User Credential drivers with non-volatile storage should also store non-volatile credential information which has changed.

36.3. Code Definitions

36.3.1. User Manager Protocol

36.3.1.1. EFI_USER_MANAGER_PROTOCOL

Summary

Reports information about a user.

GUID

#define EFI_USER_MANAGER_PROTOCOL_GUID \
  { 0x6fd5b00c, 0xd426, 0x4283, \
  { 0x98, 0x87, 0x6c, 0xf5, 0xcf, 0x1c, 0xb1, 0xfe } };

Protocol Interface Structure

typedef struct _EFI_USER_MANAGER_PROTOCOL {
  EFI_USER_PROFILE_CREATE           Create;
  EFI_USER_PROFILE_DELETE           Delete;
  EFI_USER_PROFILE_GET_NEXT         GetNext;
  EFI_USER_PROFILE_CURRENT          Current;
  EFI_USER_PROFILE_IDENTIFY         Identify;
  EFI_USER_PROFILE_FIND             Find;
  EFI_USER_PROFILE_NOTIFY           Notify;
  EFI_USER_PROFILE_GET_INFO         GetInfo;
  EFI_USER_PROFILE_SET_INFO         SetInfo;
  EFI_USER_PROFILE_DELETE_INFO      DeleteInfo;
  EFI_USER_PROFILE_GET_NEXT_INFO    GetNextInfo;
}   EFI_USER_MANAGER_PROTOCOL;

Parameters

Create: Create a new user profile.
Delete: Delete an existing user profile.
GetNext: Cycle through all user profiles.
Current: Return the current user profile.
Identify: Identify a user and set the current user profile using credentials.
Find: Find a user by a piece of user information.
Notify: Notify the user manager driver that credential information has changed.
GetInfo: Return information from a user profile.
SetInfo: Change information in a user profile.
DeleteInfo: Delete information from a user profile.
GetNextInfo: Cycle through all information from a user profile.

Description

This protocol manages user profiles.

36.3.1.2. EFI_USER_MANAGER_PROTOCOL.Create()

Summary

Create a new user profile.

Prototype

typedef
EFI_STATUS
(EFIAPI *EFI_USER_PROFILE_CREATE) (
  IN CONST EFI_USER_MANAGER_PROTOCOL        *This,
  OUT EFI_USER_PROFILE_HANDLE               *User
  );

Parameters

This: Points to this instance of the EFI_USER_MANAGER_PROTOCOL.
User: On return, points to the new user profile handle. The user profile handle is unique only during this boot.

Description

This function creates a new user profile with only a new user identifier attached and returns its handle. The user profile is non-volatile, but the handle User can change across reboots.

If the current user profile does not permit creation of new user profiles then EFI_ACCESS_DENIED will be returned. If creation of new user profiles is not supported, then EFI_UNSUPPORTED is returned.

Related Definitions

typedef VOID *EFI_USER_PROFILE_HANDLE;

Status Codes Returned

EFI_SUCCESS	User profile was successfully created.
EFI_ACCESS_DENIED	Current user does not have sufficient permissions to create a user profile.
EFI_UNSUPPORTED	Creation of new user profiles is not supported.
EFI_INVALID_PARAMETER	User is NULL.

36.3.1.3. EFI_USER_MANAGER_PROTOCOL.Delete()

Summary

Delete an existing user profile.

Prototype

typedef
EFI_STATUS
(EFIAPI *EFI_USER_PROFILE_DELETE) (
  IN CONST EFI_USER_MANAGER_PROTOCOL     *This,
  IN EFI_USER_PROFILE_HANDLE             User
  );

Parameters

This: Points to this instance of the EFI_USER_MANAGER_PROTOCOL.
User: User profile handle. Type EFI_USER_PROFILE_HANDLE is defined in Create().

Description

Delete an existing user profile. If the current user profile does not permit deletion of user profiles then EFI_ACCESS_DENIED will be returned. If there is only a single user profile then EFI_ACCESS_DENIED will be returned. If deletion of user profiles is not supported, then EFI_UNSUPPORTED will be returned.

Status Codes Returned

EFI_SUCCESS	User profile was successfully deleted.
EFI_ACCESS_DENIED	Current user does not have sufficient permissions to delete a user profile or there is only one user profile.
EFI_UNSUPPORTED	Deletion of new user profiles is not supported.
EFI_INVALID_PARAMETER	User does not refer to a valid user profile.

36.3.1.4. EFI_USER_MANAGER_PROTOCOL.GetNext()

Summary

Enumerate all of the enrolled users on the platform.

Prototype

typedef
EFI_STATUS
(EFIAPI *EFI_USER_PROFILE_GET_NEXT)(
  IN CONST EFI_USER_MANAGER_PROTOCOL      *This,
  IN OUT EFI_USER_PROFILE_HANDLE          *User
  );

Parameters

This: Points to the instance of this EFI_USER_MANAGER_PROTOCOL.
User: On entry, points to the previous user profile handle or NULL to start enumeration. On exit, points to the next user profile handle or NULL if there are no more user profiles.

Description

This function returns the next enrolled user profile. To retrieve the first user profile handle, point User at a NULL. Each subsequent call will retrieve another user profile handle until there are no more, at which point User will point to NULL.

NOTE: There is always at least one user profile.

Status Codes Returned

EFI_SUCCESS	Next enrolled user profile successfully returned.
EFI_INVALID_PARAMETER	User is NULL.
EFI_ACCESS_DENIED	Next enrolled user profile was not successfully returned.

36.3.1.5. EFI_USER_MANAGER_PROTOCOL.Current()

Summary

Return the current user profile handle.

Prototype

typedef
EFI_STATUS
(EFIAPI *EFI_USER_PROFILE_CURRENT)(
  IN CONST EFI_USER_MANAGER_PROTOCOL      *This,
  OUT EFI_USER_PROFILE_HANDLE             *CurrentUser
  );

Parameters

This: Points to this instance of the EFI_USER_MANAGER_PROTOCOL.
CurrentUser: On return, points to the current user profile handle.

Description

This function returns the current user profile handle.

Status Codes Returned

EFI_SUCCESS	Current user profile handle returned successfully.
EFI_INVALID_PARAMETER	CurrentUser is NULL.

36.3.1.6. EFI_USER_MANAGER_PROTOCOL.Identify()

Summary

Identify a user.

Prototype

typedef
EFI_STATUS
(EFIAPI *EFI_USER_IDENTIFY) (
  IN CONST EFI_USER_MANAGER_PROTOCOL      *This,
  OUT EFI_USER_PROFILE_HANDLE             *User
  );

Parameters

This: Points to the instance of the EFI_USER_MANAGER_PROTOCOL.
User: On return, points to the user profile handle for the current user profile.

Description

Identify the user and, if authenticated, returns the user handle and changes the current user profile.

All user information marked as private in a previously selected profile is no longer available for inspection.

Whenever the current user profile is changed then the event with the GUID EFI_EVENT_GROUP_USER_PROFILE_CHANGED is signaled.

The function can only be called at TPL_APPLICATION.

Related Definitions

#define EFI_EVENT_GROUP_USER_PROFILE_CHANGED \
  { 0xbaf1e6de, 0x209e, 0x4adb, \
  { 0x8d, 0x96, 0xfd, 0x8b, 0x71, 0xf3, 0xf6, 0x83 } }

Status Codes Returned

EFI_SUCCESS	User was successfully identified.
EFI_INVALID_PARAMETER	User is NULL.
EFI_ACCESS_DENIED	User was not successfully identified.

36.3.1.7. EFI_USER_MANAGER_PROTOCOL.Find()

Summary

Find a user using a user information record.

Prototype

typedef
EFI_STATUS
(EFIAPI *EFI_USER_PROFILE_FIND)(
  IN   CONST EFI_USER_MANAGER_PROTOCOL    *This,
  IN OUT EFI_USER_PROFILE_HANDLE          *User,
  IN OUT EFI_USER_INFO_HANDLE             *UserInfo OPTIONAL,
  IN   CONST EFI_USER_INFO                *Info,
  IN   UINTN                              InfoSize
  );

Parameters

This

Points to this instance of the EFI_USER_MANAGER_PROTOCOL.

User

On entry, points to the previously returned user profile handle or NULL to start searching with the first user profile. On return, points to the user profile handle or NULL if not found.

UserInfo

On entry, points to the previously returned user information handle or NULL to start searching with the first. On return, points to the user information handle of the user information record or NULL if not found. Can be NULL, in which case only one user information record per user can be returned. Type EFI_USER_INFO_HANDLE is defined in “Related Definitions” below.

Info

Points to the buffer containing the user information to be compared to the user information record.If the user information record data is empty, then only the user information record type is compared.

If InfoSize is 0, then the user information record data must be empty.

InfoSize

The size of Info, in bytes.

Description

This function searches all user profiles for the specified user information record. The search starts with the user information record handle following UserInfo and continues until either the information is found or there are no more user profiles.

A match occurs when the Info.InfoType field matches the user information record type and the user information record data matches a portion of Info.

Status Codes Returned

EFI_SUCCESS	User information was found. User points to the user profile handle and UserInfo points to the user information handle.
EFI_NOT_FOUND	User information was not found. User points to NULL and UserInfo points to NULL.
EFI_INVALID_PARAMETER	User is NULL. Or Info is NULL.

Related Definitions

typedef VOID *EFI_USER_INFO_HANDLE;

36.3.1.8. EFI_USER_MANAGER_PROTOCOL.Notify()

Summary

Called by credential provider to notify of information change.

Prototype

typedef
EFI_STATUS
  (EFIAPI *EFI_USER_PROFILE_NOTIFY)(
  IN  CONST EFI_USER_MANAGER_PROTOCOL      *This,
  IN  EFI_HANDLE                           Changed
  );

Parameters

This: Points to this instance of the EFI_USER_MANAGER_PROTOCOL.
Changed: Handle on which is installed an instance of the EFI_USER_CREDENTIAL2_PROTOCOL where the user has changed.

Description

This function allows the credential provider to notify the User Identity Manager when user status has changed.

If the User Identity Manager doesn’t support asynchronous changes in credentials, then this function should return EFI_UNSUPPORTED.

If current user does not exist, and the credential provider can identify a user, then make the user to be current user and signal the EFI_EVENT_GROUP_USER_PROFILE_CHANGED event.

If current user already exists, and the credential provider can identify another user, then switch current user to the newly identified user, and signal the EFI_EVENT_GROUP_USER_PROFILE_CHANGED event.

If current user was identified by this credential provider and now the credential provider cannot identify current user, then logout current user and signal the EFI_EVENT_GROUP_USER_PROFILE_CHANGED event.

Status Codes Returned

EFI_SUCCESS	The User Identity Manager has handled the notification.
EFI_NOT_READY	The function was called while the specified credential provider was not selected.
EFI_UNSUPPORTED	The User Identity Manager doesn’t support asynchronous notifications.

36.3.1.9. EFI_USER_MANAGER_PROTOCOL.GetInfo()

Summary

Return information attached to the user.

Prototype

typedef
EFI_STATUS
(EFIAPI *EFI_USER_PROFILE_GET_INFO)(
  IN   CONST EFI_USER_MANAGER_PROTOCOL       *This,
  IN   EFI_USER_PROFILE_HANDLE               User,
  IN   EFI_USER_INFO_HANDLE                  UserInfo,
  OUT   EFI_USER_INFO                        *Info,
  IN OUT UINTN                               *InfoSize
  );

Parameters

This: Points to this instance of the EFI_USER_MANAGER_PROTOCOL.
User: Handle of the user whose profile will be retrieved.
UserInfo: Handle of the user information data record. Type EFI_USER_INFO_HANDLE is defined in GetInfo().
Info: On entry, points to a buffer of at least * InfoSize bytes. On exit, holds the user information. If the buffer is too small to hold the information, then EFI_BUFFER_TOO_SMALL is returned and InfoSize is updated to contain the number of bytes actually required. Type EFI_USER_INFO is described in “Related Definitions” below.
InfoSize: On entry, points to the size of Info. On return, points to the size of the user information.

Description

This function returns user information. The format of the information is described in User Information. The function may return EFI_ACCESS_DENIED if the information is marked private and the handle specified by User is not the current user profile. The function may return EFI_ACCESS_DENIED if the information is marked protected and the information is associated with a credential provider for which the user has not been authenticated.

Status Codes Returned

EFI_SUCCESS	Information returned successfully.
EFI_ACCESS_DENIED	The information about the specified user cannot be accessed by the current user.
EFI_BUFFER_TOO_SMALL	The number of bytes specified by * InfoSize is too small to hold the returned data. The actual size required is returned in * InfoSize.
EFI_NOT_FOUND	User does not refer to a valid user profile or UserInfo does not refer to a valid user info handle.
EFI_INVALID_PARAMETER	Info is NULL or InfoSize is NULL

Related Definitions

typedef struct {
  EFI_GUID                 Credential;
  UINT8                    InfoType;
  UINT8                    Reserved1;
  EFI_USER_INFO_ATTRIBS    InfoAttribs;
  UINT32                   InfoSize;
}   EFI_USER_INFO;

Credential: The user credential identifier associated with this user information or else Nil if the information is not associated with any specific credential.
InfoType: The type of user information. See EFI_USER_INFO_x_RECORD in User Information for a description of the different types of user information.
Reserved1: Must be set to 0.
InfoAttribs: The attributes of the user profile information.
InfoSize: The size of the user information, in bytes, including this header.

typedef UINT16 EFI_USER_INFO_ATTRIBS;

#define EFI_USER_INFO_STORAGE                0x000F
#define EFI_USER_INFO_STORAGE_VOLATILE       0x0000
#define EFI_USER_INFO_STORAGE_CREDENTIAL_NV  0x0001
#define EFI_USER_INFO_STORAGE_PLATFORM_NV    0x0002

#define EFI_USER_INFO_ACCESS                 0x0070
#define EFI_USER_INFO_PUBLIC                 0x0010
#define EFI_USER_INFO_PRIVATE                0x0020
#define EFI_USER_INFO_PROTECTED              0x0030
#define EFI_USER_INFO_EXCLUSIVE              0x0080

The EFI_USER_INFO_STORAGE_x values describe how the user information should be stored. If EFI_USER_INFO_STORAGE_VOLATILE is specified, then the user profile information will be lost after a reboot. If EFI_USER_INFO_STORAGE_CREDENTIAL_NV is specified, then the information will be stored by the driver which created the handle Credential. If USER_INFO_STORAGE_PLATFORM_NV is specified, then the information will be stored by the User Identity Manager in platform non-volatile storage.

There are three levels of access to information associated with the user profile: public, private or protected. If EFI_USER_INFO_PUBLIC is specified, then the user profile information is available always. If EFI_USER_INFO_PRIVATE is specified, then the user profile information is only available if the user has been authenticated (whether or not they are the current user). If EFI_USER_INFO_PROTECTED is specified, then the user profile information is only available if the user has been authenticated and is the current user.

If EFI_USER_INFO_EXCLUSIVE is specified then there can only be one user information record of this type in the user profile. Attempts to use SetInfo() will fail.

36.3.1.10. EFI_USER_MANAGER_PROTOCOL.SetInfo()

Summary

Add or update user information.

Prototype

typedef
EFI_STATUS
(EFIAPI *EFI_USER_PROFILE_SET_INFO) (
  IN   CONST EFI_USER_MANAGER_PROTOCOL       *This,
  IN   EFI_USER_PROFILE_HANDLE               User,
  IN OUT EFI_USER_INFO_HANDLE                *UserInfo,
  IN   CONST EFI_USER_INFO                   *Info,
  IN   UINTN                                 InfoSize
  );

Parameters

This: Points to this instance of the EFI_USER_MANAGER_PROTOCOL.
User: Handle of the user whose profile will be changed.
UserInfo: On entry, points to the handle of the user information record to change or NULL if the user information should be added to the user profile. On exit, points to the handle of the user credential information record.
Info: Points to the user information. See EFI_USER_INFO for more information.
InfoSize: The size of Info, in bytes.

Description

This function changes user information. If NULL is pointed to by UserInfo, then a new user information record is created and its handle is returned in UserInfo. Otherwise, the existing one is replaced.

If EFI_USER_INFO_IDENTITY_POLICY_RECORD is changed, it is the caller’s responsibility to keep it to be synced with the information on credential providers.

If EFI_USER_INFO_EXCLUSIVE is specified in Info and a user information record of the same type already exists in the user profile, then EFI_ACCESS_DENIED will be returned and UserInfo will point to the handle of the existing record.

Status Codes Returned

EFI_SUCCESS	User profile information was successfully changed/added.
EFI_ACCESS_DENIED	The record is exclusive.
EFI_SECURITY_VIOLATION	The current user does not have permission to change the specified user profile or user information record.
EFI_NOT_FOUND	User does not refer to a valid user profile or UserInfo does not refer to a valid user info handle.
EFI_INVALID_PARAMETER	Info is NULL or InfoSize is NULL

36.3.1.11. EFI_USER_MANAGER_PROTOCOL.DeleteInfo()

Summary

Delete user information.

Prototype

typedef

EFI_STATUS
(EFIAPI *EFI_USER_PROFILE_DELETE_INFO) (
  IN   CONST EFI_USER_MANAGER_PROTOCOL      *This,
  IN   EFI_USER_PROFILE_HANDLE              User,
  IN   EFI_USER_INFO_HANDLE                 UserInfo
  );

Parameters

This: Points to this instance of the EFI_USER_MANAGER_PROTOCOL.
User: Handle of the user whose information will be deleted.
UserInfo: Handle of the user information to remove.

Description

Delete the user information attached to the user profile specified by the UserInfo.

Status Codes Returned

EFI_SUCCESS	User information deleted successfully.
EFI_NOT_FOUND	User information record UserInfo does not exist in the user profile.
EFI_ACCESS_DENIED	The current user does not have permission to delete this user information.

36.3.1.12. EFI_USER_MANAGER_PROTOCOL.GetNextInfo()

Summary

Enumerate all of the enrolled users on the platform.

Prototype

typedef
EFI_STATUS
(EFIAPI *EFI_USER_PROFILE_GET_NEXT_INFO)(
  IN   CONST EFI_USER_MANAGER_PROTOCOL         *This,
  IN   EFI_USER_PROFILE_HANDLE                 User,
  IN OUT EFI_USER_INFO_HANDLE                  *UserInfo
  );

Parameters

This: Points to the instance of this EFI_USER_MANAGER_PROTOCOL.
User: Handle of the user whose information will be enumerated
UserInfo: On entry, points to the previous user information handle or NULL to start enumeration. On exit, points to the next user information handle or NULL if there is no more user information.

Description

This function returns the next user information record. To retrieve the first user information record handle, point UserInfo at a NULL. Each subsequent call will retrieve another user information record handle until there are no more, at which point UserInfo will point to NULL.

Status Codes Returned

EFI_SUCCESS	User information returned.
EFI_NOT_FOUND	No more user information found.
EFI_INVALID_PARAMETER	UserInfo is NULL.

36.3.2. Credential Provider Protocols

36.3.2.1. EFI_USER_CREDENTIAL2_PROTOCOL

Summary

Provide support for a single class of credentials

GUID

#define EFI_USER_CREDENTIAL2_PROTOCOL_GUID \
  { 0xe98adb03, 0xb8b9, 0x4af8, \
  { 0xba, 0x20, 0x26, 0xe9, 0x11, 0x4c, 0xbc, 0xe5 } }

Prototype

typedef struct _EFI_USER_CREDENTIAL2_PROTOCOL {
  EFI_GUID                       Identifier;
  EFI_GUID                       Type;
  EFI_CREDENTIAL_ENROLL          Enroll;
  EFI_CREDENTIAL_FORM            Form;
  EFI_CREDENTIAL_TILE            Tile;
  EFI_CREDENTIAL_TITLE           Title;
  EFI_CREDENTIAL_USER            User;
  EFI_CREDENTIAL_SELECT          Select;
  EFI_CREDENTIAL_DESELECT        Deselect;
  EFI_CREDENTIAL_DEFAULT         Default;
  EFI_CREDENTIAL_GET_INFO        GetInfo;
  EFI_CREDENTIAL_GET_NEXT_INFO   GetNextInfo;
  EFI_CREDENTIAL_CAPABILITIES    Capabilities;
  EFI_CREDENTIAL_DELETE          Delete;
}   EFI_USER_CREDENTIAL2_PROTOCOL;

Parameters

Identifier: Uniquely identifies this credential provider.
Type: Identifies this class of User Credential Provider. See EFI_CREDENTIAL_CLASS_x in “Related Definitions” below.
Enroll: Enroll a user using this credential provider.
Form: Return the form set and form identifier for the form.
Tile: Returns an optional bitmap image used to identify this credential provider.
Title: Returns a string used to identify this credential provider.
User: Returns the user profile identifier ascertained by using this credential.
Select: Called when a credential provider is selected.
Deselect: Called when a credential provider is deselected.
Default: Returns whether the credential provider can provide the default credential.
GetInfo: Return user information provided by the credential provider.
GetNextInfo: Cycle through all user information available from the credential provider.
Capabilities: Bitmask which describes the capabilities supported by the credential provider. Type EFI_CREDENTIAL_CAPABILITIES is defined in “Related Definitions” below.
Delete: Delete a user on this credential provider.

Description

Attached to a device handle, this protocol identifies a single means of identifying the user.

If EFI_CREDENTIAL_CAPABILITIES_ENROLL is specified, then this credential provider supports the ability to enroll new user identification information using the Enroll() function.

Related Definitions

#define EFI_USER_CREDENTIAL_CLASS_UNKNOWN \
  { 0x5cf32e68, 0x7660, 0x449b, \
  { 0x80, 0xe6, 0x7e, 0xa3, 0x6e, 0x3, 0xf6, 0xa8 } };

#define EFI_USER_CREDENTIAL_CLASS_PASSWORD \
  { 0xf8e5058c, 0xccb6, 0x4714, \
  { 0xb2, 0x20, 0x3f, 0x7e, 0x3a, 0x64, 0xb, 0xd1 } };

#define EFI_USER_CREDENTIAL_CLASS_SMART_CARD \
  { 0x5f03ba33, 0x8c6b, 0x4c24, \
  { 0xaa, 0x2e, 0x14, 0xa2, 0x65, 0x7b, 0xd4, 0x54 } };

#define EFI_USER_CREDENTIAL_CLASS_FINGERPRINT \
  { 0x32cba21f, 0xf308, 0x4cbc, \
  { 0x9a, 0xb5, 0xf5, 0xa3, 0x69, 0x9f, 0x4, 0x4a } };

#define EFI_USER_CREDENTIAL_CLASS_HANDPRINT \
  { 0x5917ef16, 0xf723, 0x4bb9, \
  { 0xa6, 0x4b, 0xd8, 0xc5, 0x32, 0xf4, 0xd8, 0xb5 } };

#define EFI_USER_CREDENTIAL_CLASS_SECURE_CARD \
  { 0x8a6b4a83, 0x42fe, 0x45d2, \
  { 0xa2, 0xef, 0x46, 0xf0, 0x6c, 0x7d, 0x98, 0x52 } };

typedef UINT64 EFI_CREDENTIAL_CAPABILITIES;

#define EFI_CREDENTIAL_CAPABILITIES_ENROLL 0x0000000000000001

36.3.2.2. EFI_USER_CREDENTIAL2_PROTOCOL.Enroll()

Summary

Enroll a user on a credential provider.

Prototype

typedef
EFI_STATUS
(EFIAPI *EFI_CREDENTIAL2_ENROLL)(
  IN CONST EFI_USER_CREDENTIAL2_PROTOCOL     *This,
  IN EFI_USER_PROFILE_HANDLE                 User
  );

Parameters

This: Points to this instance of the EFI_USER_CREDENTIAL2_PROTOCOL.
User: The user profile to enroll.

Description

This function enrolls a user on this credential provider. If the user exists on this credential provider, update the user information on this credential provider; otherwise add the user information on credential provider.

Status Codes Returned

EFI_SUCCESS	User profile was successfully enrolled
EFI_ACCESS_DENIED	Current user profile does not permit enrollment on the user profile handle. Either the user profile cannot enroll on any user profile or cannot enroll on a user profile other than the current user profile.
EFI_UNSUPPORTED	This credential provider does not support enrollment in the pre-OS.
EFI_DEVICE_ERROR	The new credential could not be created because of a device error.
EFI_INVALID_PARAMETER	User does not refer to a valid user profile handle.

36.3.2.3. EFI_USER_CREDENTIAL2_PROTOCOL.Form()

Summary

Returns the user interface information used during user identification.

Prototype

typedef
EFI_STATUS
(EFIAPI *EFI_CREDENTIAL_FORM)(
  IN CONST EFI_USER_CREDENTIAL2_PROTOCOL     *This,
  OUT EFI_HII_HANDLE                         *Hii,
  OUT EFI_GUID                               *FormSetId,
  OUT EFI_FORM_ID                            *FormId
  );

Parameters

This: Points to this instance of the EFI_USER_CREDENTIAL2_PROTOCOL.
Hii: On return, holds the HII database handle. Type EFI_HII_HANDLE is defined in EFI_HII_DATABASE_PROTOCOL.NewPackageList() in the Packages section.
FormSetId: On return, holds the identifier of the form set which contains the form used during user identification.
FormId: On return, holds the identifier of the form used during user identification.

Description

This function returns information about the form used when interacting with the user during user identification. The form is the first enabled form in the form-set class EFI_HII_USER_CREDENTIAL_FORMSET_GUID installed on the HII handle HiiHandle. If the user credential provider does not require a form to identify the user, then this function should return EFI_NOT_FOUND.

Status Codes Returned

EFI_SUCCESS	Form returned successfully.
EFI_NOT_FOUND	Form not returned.
EFI_INVALID_PARAMETER	Hii is NULL or FormSetId is NULL or FormId is NULL

36.3.2.4. EFI_USER_CREDENTIAL2_PROTOCOL.Tile()

Summary

Returns bitmap used to describe the credential provider type.

Prototype

typedef
EFI_STATUS
(EFIAPI *EFI_CREDENTIAL_TILE)(
  IN    CONST EFI_USER_CREDENTIAL2_PROTOCOL        *This,
  IN OUT UINTN                                     *Width,
  IN OUT UINTN                                     *Height,
  OUT   EFI_HII_HANDLE                             *Hii,
  OUT   EFI_IMAGE_ID                               *Image
  );

Parameters

This: Points to this instance of the EFI_USER_CREDENTIAL2_PROTOCOL.
Width: On entry, points to the desired bitmap width. If NULL then no bitmap information will be returned. On exit, points to the width of the bitmap returned.
Height: On entry, points to the desired bitmap height. If NULL then no bitmap information will be returned. On exit, points to the height of the bitmap returned.
Hii: On return, holds the HII database handle. Type EFI_HII_HANDLE is defined in EFI_HII_DATABASE_PROTOCOL.NewPackageList() in the Packages section.
Image: On return, holds the HII image identifier. Type EFI_IMAGE_ID is defined in this specification, Image Protocol .

Description

This optional function returns a bitmap which is less than or equal to the number of pixels specified by Width and Height. If no such bitmap exists, then EFI_NOT_FOUND is returned.

Status Codes Returned

EFI_SUCCESS	Image identifier returned successfully.
EFI_NOT_FOUND	Image identifier not returned.
EFI_INVALID_PARAMETER	Hii is NULL or Image is NULL.

36.3.2.5. EFI_USER_CREDENTIAL2_PROTOCOL.Title()

Summary

Returns string used to describe the credential provider type.

Prototype

typedef
EFI_STATUS
(EFIAPI *EFI_CREDENTIAL_TITLE)(
  IN    CONST EFI_USER_CREDENTIAL2_PROTOCOL     *This,
  OUT   EFI_HII_HANDLE                          *Hii,
  OUT   EFI_STRING_ID                           *String
  );

Parameters

This: Points to this instance of the EFI_USER_CREDENTIAL2_PROTOCOL .
Hii: On return, holds the HII database handle. TType EFI_HII_HANDLE is defined in EFI_HII_DATABASE_PROTOCOL.NewPackageList() in the Packages section.
String: On return, holds the HII string identifier. Type EFI_STRING_ID is defined in EFI_IFR_OP_HEADER.

Description

This function returns a string which describes the credential provider. If no such string exists, then EFI_NOT_FOUND is returned.

Status Codes Returned

EFI_SUCCESS	String identifier returned successfully.
EFI_NOT_FOUND	String identifier not returned.
EFI_INVALID_PARAMETER	Hii is NULL or String is NULL

36.3.2.6. EFI_USER_CREDENTIAL2_PROTOCOL.User()

Summary

Return the user identifier associated with the currently authenticated user.

Prototype

typedef
EFI_STATUS
(EFIAPI *EFI_CREDENTIAL_USER)(
  IN   CONST EFI_USER_CREDENTIAL2_PROTOCOL      *This,
  IN   EFI_USER_PROFILE_HANDLE                  User,
  OUT  EFI_USER_INFO_IDENTIFIER                 *Identifier
  );

Parameters

This: Points to this instance of the EFI_USER_CREDENTIAL2_PROTOCOL .
User: The user profile handle of the user profile currently being considered by the user identity manager. If NULL, then no user profile is currently under consideration.
Identifier: On return, points to the user identifier. Type EFI_USER_INFO_IDENTIFIER is defined in “Related Definitions” below.

Description

This function returns the user identifier of the user authenticated by this credential provider. This function is called after the credential-related information has been submitted on a form OR after a call to Default() has returned that this credential is ready to log on.

This function can return one of five possible responses:

If no user profile can yet be identified, then EFI_NOT_READY is returned.
If the user has been locked out, then EFI_ACCESS_DENIED is returned.
If the user specified by User is identified, then Identifier returns with the user identifier associated with that handle and EFI_SUCCESS is returned.
If Identifier is NULL, then EFI_INVALID_PARAMETER is returned.
If specified User does not refer to a valid user profile, then EFI_NOT_FOUND is returned.

Status Codes Returned

EFI_SUCCESS	User identifier returned successfully.
EFI_NOT_READY	No user identifier can be returned.
EFI_ACCESS_DENIED	The user has been locked out of this user credential.
EFI_NOT_FOUND	User is not NULL, and the specified user handle can’t be found in user profile database
EFI_INVALID_PARAMETER	Identifier is NULL.

36.3.2.7. EFI_USER_CREDENTIAL2_PROTOCOL.Select()

Summary

Indicate that user interface interaction has begun for the specified credential.

Prototype

typedef
EFI_STATUS
(EFIAPI *EFI_CREDENTIAL_SELECT)(
  IN CONST EFI_USER_CREDENTIAL2_PROTOCOL     *This,
  OUT EFI_CREDENTIAL_LOGON_FLAGS             *AutoLogon
  );

Parameters

This: Points to this instance of the EFI_USER_CREDENTIAL2_PROTOCOL .
AutoLogon: On return, points to the credential provider’s capabilities after the credential provider has been selected by the user. Type EFI_CREDENTIAL_LOGON_FLAGS is defined in “Related Definitions” below.

Description

This function is called when a credential provider is selected by the user. If AutoLogon returns FALSE, then the user interface will be constructed by the User Identity Manager.

Related Definitions

typedef UINT32 EFI_CREDENTIAL_LOGON_FLAGS;

#define EFI_CREDENTIAL_LOGON_FLAG_AUTO       0x00000001
#define EFI_CREDENTIAL_LOGON_FLAG_DEFAULT    0x00000002

If EFI_CREDENTIAL_LOGON_FLAG_AUTO is set, then the User Identity Manager may use this as a hint to try logging on immediately. If not set, then the User Identity Manager may use this as an indication to wait for the user to submit the information.

If EFI_CREDENTIAL_LOGON_FLAG_DEFAULT is set, then the User Identity Manager may use this as a hint to use this credential provider as the default credential provider. If more than one credential provider returns with this set, then the selection is implementation specific. If EFI_CREDENTIAL_LOGON_FLAG_DEFAULT is set and EFI_CREDENTIAL_LOGON_FLAG_AUTO is set then the User Identity Manager may uses this as a hint to log the user on immediately.

Status Codes Returned

EFI_SUCCESS	Credential provider successfully selected.
EFI_INVALID_PARAMETER	AutoLogon is NULL

36.3.2.8. EFI_USER_CREDENTIAL2_PROTOCOL.Deselect()

Summary

Indicate that user interface interaction has ended for the specified credential.

Prototype

typedef
EFI_STATUS
(EFIAPI *EFI_CREDENTIAL_DESELECT)(
  IN CONST EFI_USER_CREDENTIAL2_PROTOCOL     *This
  );

Parameters

This: Points to this instance of the EFI_USER_CREDENTIAL2_PROTOCOL.

Description

This function is called when a credential provider is deselected by the user.

Status Codes Returned

EFI_SUCCESS

Credential provider successfully selected.

36.3.2.9. EFI_USER_CREDENTIAL2_PROTOCOL.Default()

Summary

Return the default logon behavior for this user credential.

Prototype

typedef
EFI_STATUS
(EFIAPI *EFI_CREDENTIAL_DEFAULT)(
  IN CONST EFI_USER_CREDENTIAL2_PROTOCOL     *This,
  OUT EFI_CREDENTIAL_LOGON_FLAGS             *AutoLogon
  );

Parameters

This: Points to this instance of the EFI_USER_CREDENTIAL2_PROTOCOL .
AutoLogon: On return, holds whether the credential provider should be used by default to automatically log on the user. Type EFI_CREDENTIAL_LOGON_FLAGS is defined in EFI_USER_CREDENTIAL2_PROTOCOL.Select().

Description

This function reports the default login behavior regarding this credential provider.

Status Codes Returned

EFI_SUCCESS	Default information successfully returned.
EFI_INVALID_PARAMETER	AutoLogon is NULL

36.3.2.10. EFI_USER_CREDENTIAL2_PROTOCOL.GetInfo()

Summary

Return information attached to the credential provider.

Prototype

typedef
EFI_STATUS
(EFIAPI *EFI_CREDENTIAL_GET_INFO)(
  IN   CONST EFI_USER_CREDENTIAL2_PROTOCOL      *This,
  IN   EFI_USER_INFO_HANDLE                     UserInfo,
  OUT   EFI_USER_INFO                           *Info,
  IN OUT UINTN                                  *InfoSize
  );

Parameters

This: Points to this instance of the EFI_USER_CREDENTIAL2_PROTOCOL .
UserInfo: Handle of the user information data record. Type EFI_USER_INFO_HANDLE is defined in GetInfo().
Info: On entry, points to a buffer of at least **InfoSize* bytes. On exit, holds the user information. If the buffer is too small to hold the information, then EFI_BUFFER_TOO_SMALL is returned and InfoSize is updated to contain the number of bytes actually required. Type EFI_USER_INFO is described in “Related Definitions” below.
InfoSize: On entry, points to the size of Info. On return, points to the size of the user information.

Description

This function returns user information.

Status Codes Returned

EFI_SUCCESS	Information returned successfully.
EFI_BUFFER_TOO_SMALL	The size specified by InfoSize is too small to hold all of the user information. The size required is returned in * InfoSize.
EFI_NOT_FOUND	The specified UserInfo does not refer to a valid user info handle
EFI_INVALID_PARAMETER	Info is NULL or InfoSize is NULL

36.3.2.11. EFI_USER_CREDENTIAL2_PROTOCOL.GetNextInfo()

Summary

Enumerate all of the user information records on the credential provider.

Prototype

typedef
EFI_STATUS
(EFIAPI *EFI_USER_CREDENTIAL_GET_NEXT_INFO)(
  IN   CONST EFI_USER_CREDENTIAL2_PROTOCOL      *This,
  IN OUT EFI_USER_INFO_HANDLE                   *UserInfo
  );

Parameters

This: Points to the instance of this EFI_USER_CREDENTIAL2_PROTOCOL .
UserInfo: On entry, points to the previous user information handle or NULL to start enumeration. On exit, points to the next user information handle or NULL if there is no more user information.

Description

This function returns the next user information record. To retrieve the first user information record handle, point UserInfo at a NULL. Each subsequent call will retrieve another user information record handle until there are no more, at which point UserInfo will point to NULL.

Status Codes Returned

EFI_SUCCESS	User information returned.
EFI_NOT_FOUND	No more user information found.
EFI_INVALID_PARAMETER	UserInfo is NULL.

36.3.2.12. EFI_USER_CREDENTIAL2_PROTOCOL.Delete()

Summary

Delete a user on a credential provider.

Prototype

typedef
EFI_STATUS (EFIAPI *EFI_CREDENTIAL_DELETE)(
  IN  CONST EFI_USER_CREDENTIAL2_PROTOCOL    *This,
  IN  EFI_USER_PROFILE_HANDLE                User
  );

Parameters

This: Points to this instance of the EFI_USER_CREDENTIAL2_PROTOCOL.
User: The user profile handle to delete.

Description

This function deletes a user on this credential provider.

Status Codes Returned

EFI_SUCCESS	User profile was successfully deleted .
EFI_ACCESS_DENIED	Current user profile does not permit deletion on the user profile handle. Either the user profile cannot delete on any user profile or cannot delete on a user profile other than the current user profile.
EFI_UNSUPPORTED	This credential provider does not support deletion in the pre-OS.
EFI_DEVICE_ERROR	The new credential could not be deleted because of a device error.
EFI_INVALID_PARAMETER	User does not refer to a valid user profile handle.

36.3.3. Deferred Image Load Protocol

36.3.3.1. EFI_DEFERRED_IMAGE_LOAD_PROTOCOL

Summary

Enumerates images whose load was deferred due to security considerations.

GUID

#define EFI_DEFERRED_IMAGE_LOAD_PROTOCOL_GUID \
  { 0x15853d7c, 0x3ddf, 0x43e0, \
  { 0xa1, 0xcb, 0xeb, 0xf8, 0x5b, 0x8f, 0x87, 0x2c } };

Protocol Interface Structure

typedef struct _EFI_DEFERRED_IMAGE_LOAD_PROTOCOL {
  EFI_DEFERRED_IMAGE_INFO GetImageInfo();
}   EFI_DEFERRED_IMAGE_LOAD_PROTOCOL;

Members

GetImageInfo: Return information about a single deferred image. See GetImageInfo() for more information.

Description

This protocol returns information about images whose load was denied because of security considerations. This information can be used by the Boot Manager or another agent to reevaluate the images when the current security profile has been changed, such as when the current user profile changes. There can be more than one instance of this protocol installed.

36.3.3.2. EFI_DEFERRED_IMAGE_LOAD_PROTOCOL.GetImageInfo()

Summary

Returns information about a deferred image.

Prototype

typedef
EFI_STATUS
(EFIAPI *EFI_DEFERRED_IMAGE_INFO)(
  IN EFI_DEFERRED_IMAGE_LOAD_PROTOCOL     *This,
  IN UINTN                                ImageIndex,
  OUT  EFI_DEVICE_PATH_PROTOCOL           **ImageDevicePath,
  OUT  VOID                               **Image,
  OUT  UINTN                              *ImageSize,
  OUT  BOOLEAN                            *BootOption
  );

Parameters

This: Points to this instance of the EFI_DEFERRED_IMAGE_LOAD_PROTOCOL.
ImageIndex: Zero-based index of the deferred index.
ImageDevicePath: On return, points to a pointer to the device path of the image. The device path should not be freed by the caller.
Image: On return, points to the first byte of the image or NULL if the image is not available. The image should not be freed by the caller unless LoadImage() has been called successfully.
ImageSize: On return, the size of the image, or 0 if the image is not available.
BootOption: On return, points to TRUE if the image was intended as a boot option or FALSE if it was not intended as a boot option.

Description

This function returns information about a single deferred image. The deferred images are numbered consecutively, starting with 0. If there is no image which corresponds to ImageIndex, then EFI_NOT_FOUND is returned. , All deferred images may be returned by iteratively calling this function until EFI_NOT_FOUND is returned.

Image may be NULL and ImageSize set to 0 if the decision to defer execution was made because of the location of the executable image rather than its actual contents.

Status Codes Returned

EFI_SUCCESS	Image information returned successfully.
EFI_NOT_FOUND	ImageIndex does not refer to a valid image.
EFI_INVALID_PARAMETER	ImageDevicePath is NULL or Image is NULL or ImageSize is NULL or BootOption is NULL

36.4. User Information

This section describes the different user information and the format of the data. Each of the following records is prefixed with the EFI_USER_INFO structure. The format of the record is determined by the type specified by the InfoType field in the structure, as listed in the table below:

Record values and descriptions

Table 36.1 Record Values and Descriptions
Name	Value	Description
EFI_USER_INFO_EMPTY_RECORD	0x00	No information.
EFI_USER_INFO_NAME_RECORD	0x01	User’s name
EFI_US ER_INFO_CREATE_DATE_RECORD	0x02	Date which the user profile was created.
EFI_U SER_INFO_USAGE_DATE_RECORD	0x03	Date which the user profile was last modified.
EFI_US ER_INFO_USAGE_COUNT_RECORD	0x04	Number of times the credential has been used.
EFI_U SER_INFO_IDENTIFIER_RECORD	0x05	User’s unique identifier *
EFI_USER_I NFO_CREDENTIAL_TYPE_RECORD	0x06	Credential type.
EFI_USER_INFO_C REDENTIAL_TYPE_NAME_RECORD	0x07	Credential type name.
EFI_USER_INFO_ CREDENTIAL_PROVIDER_RECORD	0x08	Credential provider
EFI_USER_INFO_CREDE NTIAL_PROVIDER_NAME_RECORD	0x09	Credential provider name
EFI_USER_INFO_PKCS11_RECORD	0x0A	PKCS11 Data Object
EFI_USER_INFO_CBEFF_RECORD	0x0B	ISO 19785 (Common Biometric Exchange Formats Framework) Data Object
EFI_USER_INFO_FAR_RECORD	0x0C	How exact a match is required for biometric identification, measured in percentage.
EFI_USER_INFO_RETRY_RECORD	0x0D	Number of retries allowed during verification.
EFI_USER _INFO_ACCESS_POLICY_RECORD	0x0E	Access control information.
EFI_USER_I NFO_IDENTITY_POLICY_RECORD	0x0F	User identity expression.
EFI_USER_INFO_GUID_RECORD	0xFF	Extended profile information, qualified by a GUID in the header.

36.4.1. EFI_USER_INFO_ACCESS_POLICY_RECORD

Summary

Provides the user’s pre-OS access rights.

Prototype

#define EFI_USER_INFO_ACCESS_POLICY_RECORD 0x0E

typedef EFI_USER_INFO_ACCESS_CONTROL EFI_USER_INFO_ACCESS_POLICY;

Description

This structure described the access policy for the user. There can be, at most, one access policy record per credential (including NULL credential). Policy records with a credential specified means that the policy is associated specifically with the credential.

The policy is detailed in a series of encapsulated records of type EFI_USER_INFO_ACCESS_CONTROL.

Related Definitions

typedef struct {
  UINT32          Type;
  UINT32          Size;
} EFI_USER_INFO_ACCESS_CONTROL;

36.4.1.1. EFI_USER_INFO_ACCESS_FORBID_LOAD

Summary

Forbids the user from booting or loading executables from the specified device path or any child device paths.

Prototype

#define EFI_USER_INFO_ACCESS_FORBID_LOAD 0x00000001

Description

This record prohibits the user from loading any executables from zero or device paths or any child device paths. The device paths may contain a specific executable name, in which case the prohibition applies to only that executable.

The record is a series of normal UEFI device paths (not multi-instance device paths).

This prohibition is overridden by the EFI_USER_INFO_ACCESS_PERMIT_LOAD record.

36.4.1.2. EFI_USER_INFO_ACCESS_PERMIT_LOAD

Summary

Permits the user from booting or loading executables from the specified device path or any child device paths.

Prototype

#define EFI_USER_INFO_ACCESS_PERMIT_LOAD 0x00000002

Description

This record allows the user to load executables from locations specified by zero or more device paths or child paths. The device paths may contain specific executable names, in which case, the permission applies only to that executable.

The record is a series of normal UEFI device paths (not multi-instance device paths).

This prohibition overrides any restrictions put in place by the EFI_USER_INFO_ACCESS_FORBID_LOAD record.

36.4.1.3. EFI_USER_INFO_ACCESS_ENROLL_SELF

Summary

Presence of this record indicates that a user can update enrollment information.

Prototype

#define EFI_USER_INFO_ACCESS_ENROLL_SELF 0x00000003

Description

If this record is present, then the pre-OS environment will allow the user to initiate an update of authentication information for his/her own profile, but not other user information or other user’s information. This would allow, for example, fingerprint update or password change.

There is no data for this record.

36.4.1.4. EFI_USER_INFO_ACCESS_ENROLL_OTHERS

Summary

Presence of this record indicates that a user can enroll new users.

Prototype

#define EFI_USER_INFO_ACCESS_ENROLL_OTHERS 0x00000004

Description

If this record is present, then the pre-OS environment will allow the user to initiate enrollment of new user profiles. It does not give permission to update existing user profiles.

There is no data for this record.

36.4.1.5. EFI_USER_INFO_ACCESS_MANAGE

Summary

Presence of this record indicates that a user can update the user information of any user.

Prototype

#define EFI_USER_INFO_ACCESS_MANAGE 0x00000005

Description

If this record is present, then the pre-OS environment will allow the user to update any information about his/her own profile or other profiles.

There is no data for this record.

36.4.1.6. EFI_USER_INFO_ACCESS_SETUP

Summary

Describes permissions usable when configuring the platform.

Prototype

#define EFI_USER_INFO_ACCESS_SETUP 0x00000006

Description

This record describes access permission for use in configuring the platform using an UEFI Forms Processor using zero or more GUIDs. There are three standard values (see below) and any number of others may be added.

Standard values for access to configure the platform

Table 36.2 Standard Values for Access to Configure the Platform
EFI_USER_INFO_ACCESS_SETUP_ADMIN_GUID	System administrator only.
EFI_USER_INFO_ACCESS_SETUP_NORMAL_GUID	Normal user.
EFI_USER_INFO_ACCESS_SETUP_RESTRICTED_GUID	Restricted user.

Related Definitions

#define EFI_USER_INFO_ACCESS_SETUP_ADMIN_GUID \
  { 0x85b75607, 0xf7ce, 0x471e, \
  { 0xb7, 0xe4, 0x2a, 0xea, 0x5f, 0x72, 0x32, 0xee }  };

#define EFI_USER_INFO_ACCESS_SETUP_NORMAL_GUID \
  { 0x1db29ae0, 0x9dcb, 0x43bc, \
  { 0x8d, 0x87, 0x5d, 0xa1, 0x49, 0x64, 0xdd, 0xe2 }  };

#define EFI_USER_INFO_ACCESS_SETUP_RESTRICTED_GUID \
  { 0xbdb38125, 0x4d63, 0x49f4, \
  { 0x82, 0x12, 0x61, 0xcf, 0x5a, 0x19, 0x0a, 0xf8 }  };

36.4.1.7. EFI_USER_INFO_ACCESS_FORBID_CONNECT

Summary

Forbids UEFI drivers from being started from the specified device path(s) or any child device paths.

Prototype

#define EFI_USER_INFO_ACCESS_FORBID_CONNECT 0x00000007

Description

This record prohibits UEFI drivers from being started from the specified device path(s) or any of their child device path(s). This is enforced in the ConnectController() function.

This record prohibits the user from loading a device driver associated with zero or more device paths or their child paths.

The record is a series of normal UEFI device paths (not multi-instance device paths).

This prohibition is overridden by the EFI_USER_INFO_ACCESS_PERMIT_CONNECT record.

36.4.1.8. EFI_USER_INFO_ACCESS_PERMIT_CONNECT

Summary

Permits UEFI drivers to be started on the specified device path(s) or any child device paths.

Prototype

#define EFI_USER_INFO_ACCESS_PERMIT_CONNECT 0x00000008

Description

This record allows loading of device drivers associated with zero or more device paths or their child paths.

The record is a series of normal UEFI device paths (not multi-instance device paths).

This prohibition overrides any restrictions put in place by the EFI_USER_INFO_ACCESS_FORBID_CONNECT record.

36.4.1.9. EFI_USER_INFO_ACCESS_BOOT_ORDER

Summary

Modifies the boot order.

Prototype

#define EFI_USER_INFO_ACCESS_BOOT_ORDER            0x00000009

typedef UINT32 EFI_USER_INFO_ACCESS_BOOT_ORDER_HDR;

#define EFI_USER_INFO_ACCESS_BOOT_ORDER_MASK       0x000F
#define EFI_USER_INFO_ACCESS_BOOT_ORDER_INSERT     0x0000
#define EFI_USER_INFO_ACCESS_BOOT_ORDER_APPEND     0x0001
#define EFI_USER_INFO_ACCESS_BOOT_ORDER_REPLACE    0x0002

#define EFI_USER_INFO_ACCESS_BOOT_ORDER_NODEFAULT  0x0010

Description

This exclusive record allows the user profile to insert new boot options at the beginning of the boot order ( EFI_USER_INFO_ACCESS_BOOT_ORDER_INSERT ), append new boot options to the end of the boot order ( EFI_USER_INFO_ACCESS_BOOT_ORDER_APPEND ) or replace the entire boot order ( EFI_USER_INFO_ACCESS_BOOT_ORDER_REPLACE). If EFI_USER_INFO_ACCESS_BOOT_ORDER_NODEFAULT is specified then the Boot Manager will not attempt find a default boot device when the default boot order is does not lead to a bootable device.

The boot options specified by this record are still subject to the permissions specified by EFI_USER_INFO_ACCESS_FORBID_LOAD and EFI_USER_INFO_ACCESS_PERMIT_LOAD.

The record consists of a single EFI_USER_INFO_ACCESS_BOOT_ORDER_HDR followed by zero or more UEFI device paths.

36.4.2. EFI_USER_INFO_CBEFF_RECORD

Summary

Provides standard biometric information in the format specified by the ISO 19785 (Common Biometric Exchange Formats Framework) specification.

Prototype

#define EFI_USER_INFO_CBEFF_RECORD 0x0B
typedef VOID *EFI_USER_INFO_CBEFF;

36.4.3. EFI_USER_INFO_CREATE_DATE_RECORD

Summary

Provides the date and time when the user profile was created.

Prototype

#define EFI_USER_INFO_CREATE_DATE_RECORD 0x02
typedef EFI_TIME EFI_USER_INFO_CREATE_DATE;

Description

The optional record describing the date and time when the user profile was created. Type EFI_TIME is defined in GetTime() in this specification.

36.4.4. EFI_USER_INFO_CREDENTIAL_PROVIDER_RECORD

Summary

Specifies the credential provider.

Prototype

#define EFI_USER_INFO_CREDENTIAL_PROVIDER_RECORD 0x08
typedef EFI_GUID EFI_USER_INFO_CREDENTIAL_PROVIDER;

Description

This record specifies the credential provider via a unique GUID. The credential’s handle is found in the EFI_USER_INFO structure associated with this user information record.

36.4.5. EFI_USER_INFO_CREDENTIAL_PROVIDER_NAME_RECORD

Summary

Specifies the user-readable name of a particular credential’s provider.

Prototype

#define EFI_USER_INFO_CREDENTIAL_PROVIDER_NAME_RECORD 0x09
typedef CHAR16 *EFI_USER_INFO_CREDENTIAL_PROVIDER_NAME;

Description

This record specifies the null-terminated name of a particular credential provider. The credential’s handle is found in the EFI_USER_INFO structure associated with this user information record.

36.4.6. EFI_USER_INFO_CREDENTIAL_TYPE_RECORD

Summary

Specifies the type of a particular credential associated with the user profile.

Prototype

#define EFI_USER_INFO_CREDENTIAL_TYPE_RECORD 0x06
typedef EFI_GUID EFI_USER_INFO_CREDENTIAL_TYPE;

Description

This record specifies the type of a particular credential. The credential’s identifier is found in the Credential field of the EFI_USER_INFO structure. The credential types are listed with the EFI_USER_CREDENTIAL2_PROTOCOL.

36.4.7. EFI_USER_INFO_CREDENTIAL_TYPE_NAME_RECORD

Summary

Specifies the user-readable name of a particular credential type.

Prototype

#define EFI_USER_INFO_CREDENTIAL_TYPE_NAME_RECORD 0x07
typedef CHAR16 *EFI_USER_INFO_CREDENTIAL_TYPE_NAME;

Description

This record specifies the null-terminated name of a particular credential type. The credential’ handle is found in the EFI_USER_INFO structure associated with this user information record

36.4.8. EFI_USER_INFO_GUID_RECORD

Summary

Provides placeholder for additional user profile information identified by a GUID.

Prototype

#define EFI_USER_INFO_GUID_RECORD 0xFF
typedef EFI_GUID EFI_USER_INFO_GUID;

Description

This record type provides extensibility by prefixing further data fields in the record with a GUID which identifies the format.

36.4.9. EFI_USER_INFO_FAR_RECORD

Summary

Indicates how close of a match the fingerprint must be in order to be considered a match.

Prototype

#define EFI_USER_INFO_FAR_RECORD 0x0C
typedef UINT8 EFI_USER_INFO_FAR;

Description

This record specifies how accurate the fingerprint template match must be in order to be considered a match, as a percentage from 0 (no match) to 100 (perfect match). The accuracy may be for all fingerprint sensors ( EFI_USER_INFO. Credential is zero) or for a particular fingerprint sensor ( EFI_USER_INFO .Credential is non-zero).

Access:

Exclusive: No

Modify: Only with user-enrollment permissions.

Visibility: Public

36.4.10. EFI_USER_INFO_IDENTIFIER_RECORD

Summary

Provides a unique non-volatile user identifier for each enrolled user.

Prototype

#define EFI_USER_INFO_IDENTIFIER_RECORD 0x05
typedef UINT8 EFI_USER_INFO_IDENTIFIER[16];

Description

The user identifier is unique to each enrolled user and non-volatile. Each user profile must have exactly one of these user information records installed. The format of the value is not specified.

Access

Exclusive: Yes

Modify: Only with user-enrollment permissions.

Visibility: Public.

36.4.11. EFI_USER_INFO_IDENTITY_POLICY_RECORD

Summary

Provides the expression which determines which credentials are required to assert user identity.

Prototype

#define EFI_USER_INFO_IDENTITY_POLICY_RECORD 0x0F
typedef struct {
  UINT32          Type;
  UINT32          Length;
}   EFI_USER_INFO_IDENTITY_POLICY;

Parameters

Description

The user identity policy is an expression mad3e up of operators and data items. If the expression evaluates to TRUE, then this user profile can be selected as the current profile. If the expression evaluates to FALSE, then this user profile cannot be selected as the current profile.

Data items are pushed onto an expression stack. Operators pop items off of the expression stack, perform an operator and push the results back.

NOTE: If there is no user profile, then FALSE is assumed.

Access

Exclusive: Yes

Modify: Only with user-enrollment permissions.

Visibility: Public.

Related Definitions

#define EFI_USER_INFO_IDENTITY_FALSE               0x00
#define EFI_USER_INFO_IDENTITY_TRUE                0x01
#define EFI_USER_INFO_IDENTITY_CREDENTIAL_TYPE     0x02
#define EFI_USER_INFO_IDENTITY_CREDENTIAL_PROVIDER 0x03
#define EFI_USER_INFO_IDENTITY_NOT                 0x10
#define EFI_USER_INFO_IDENTITY_AND                 0x11
#define EFI_USER_INFO_IDENTITY_OR                  0x12

Type Name	Description
EFI_USER_INFO_IDENTITY_FALSE	Push FALSE on to the expression stack.
EFI_USER_INFO_IDENTITY_TRUE	Push TRUE on to the expression stack.
EFI_USER_INFO_IDENTITY_CREDENTIAL_TYPE	If a credential provider with the specified class asserts the user’s identity, push TRUE. Otherwise push FALSE. The EFI_USER_INFO_IDENTITY_POLICY structure is followed immediately by a GUID.
EFI_USER_INFO_IDENTITY_CREDENTIAL_PROVIDER	If a credential provider with the specified provider identifier asserts the user’s identity, push TRUE. Otherwise, push FALSE. The EFI_USER_INFO_IDENTITY_POLICY structure is followed immediately by a GUID.
EFI_USER_INFO_IDENTITY_NOT	Pop a boolean off the stack. If TRUE, then push FALSE. If FALSE, then push TRUE.
EFI_USER_INFO_IDENTITY_AND	Pop two Booleans off the stack. If both are TRUE, then push TRUE. Otherwise push FALSE
EFI_USER_INFO_IDENTITY_OR	Pop two Booleans off the stack. If either is TRUE, then push TRUE. Otherwise push FALSE.

36.4.12. EFI_USER_INFO_NAME_RECORD

Summary

Provide the user’s name for the enrolled user.

Prototype

#define EFI_USER_INFO_NAME_RECORD 0x01
typedef CHAR16 *EFI_USER_INFO_NAME;

Description

The user’s name is a NULL-terminated string.

Access

Exclusive: Yes

Visibility: Public.

36.4.13. EFI_USER_INFO_PKCS11_RECORD

Summary

Provides PKCS#11 credential information from a smart card.

Prototype

#define EFI_USER_INFO_PKCS11_RECORD 0x0A

36.4.14. EFI_USER_INFO_RETRY_RECORD

Summary

Indicates how many attempts the user has to with a particular credential before the system prevents further attempts.

Prototype

#define EFI_USER_INFO_RETRY_RECORD 0x0D
typedef UINT8 EFI_USER_INFO_RETRY;

Description

This record indicates the number of times the user may fail identification with all credential providers ( EFI_USER_INFO .Credential is zero) or a particular credential provider ( EFI_USER_INFO .Credential is non-zero).

Access:

Exclusive: No

Modify: Only with user-enrollment permissions.

Visibility: Public

36.4.15. EFI_USER_INFO_USAGE_DATE_RECORD

Summary

Provides the date and time when the user profile was selected.

Prototype

#define EFI_USER_INFO_USAGE_DATE_RECORD 0x03
typedef EFI_TIME EFI_USER_INFO_USAGE_DATE;

Description

The optional record describing the date and time when the user profile was last selected. Type EFI_TIME is defined in GetTime() in this specification.

36.4.16. EFI_USER_INFO_USAGE_COUNT_RECORD

Summary

Provides the number of times that the user profile has been selected.

Prototype

#define EFI_USER_INFO_USAGE_COUNT 0x04
typedef UINT64 EFI_USER_INFO_USAGE_COUNT;

Description

The optional record describing the number of times that the user profile was selected.

36.5. User Information Table

Summary

A collection of EFI_USER_INFO records, prefixed with this header.

Prototype

typedef struct {
  UINT64                Size;
}   EFI_USER_INFO_TABLE;

Members

Size: Total size of the user information table, in bytes.

Description

This header is followed by a series of records. Each record is prefixed by the EFI_USER_INFO structure. The total size of this header and all records is equal to Size.