| /* |
| * Copyright (C) 2018 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package android.hardware.biometrics.face@1.0; |
| |
| import IBiometricsFaceClientCallback; |
| |
| /** |
| * The HAL interface for biometric face authentication. |
| */ |
| interface IBiometricsFace { |
| |
| /** |
| * Sets the current client callback. |
| * |
| * Registers a user function that must receive notifications from the HAL. |
| * There is usually only one client (FaceService). This call must block |
| * if the HAL state machine is in busy state until the HAL leaves the |
| * busy state. |
| * |
| * All callback methods pass a deviceId to differentiate callback |
| * invocations in the case where multiple sensors exist. |
| * |
| * @param clientCallback The client defined callback to register. |
| * @return result, with its "value" parameter representing a "deviceId", |
| * which must be unique for a given sensor. |
| */ |
| @callflow(next={"setActiveUser"}) |
| @entry |
| setCallback(IBiometricsFaceClientCallback clientCallback) |
| generates (OptionalUint64 result); |
| |
| /** |
| * Sets the active user, which all subsequent HAL operations are applied to. |
| * |
| * HAL service implementors must ensure that operations are restricted to |
| * the given user. Clients must not call any part of this interface, except |
| * for setCallback(), without first having set an active user. The |
| * implementation is responsible for cancelling the current operation and |
| * returning to the idle state. Calling this method with the same userId |
| * should have no effect on the state machine. |
| * |
| * Note that onLockoutChanged() MUST be invoked by the implementation in |
| * response to a user change in order to update the framework with the |
| * timeout of the new user (or 0 if the user is not locked out). |
| * |
| * @param userId A non-negative user identifier that must be unique and |
| * persistent for a given user. |
| * @param storePath absolute filesystem path to the template storage |
| * directory. This must be the /data/vendor_de/<user>/facedata |
| * directory specified by the SeLinux policy. |
| */ |
| @callflow(next={"authenticate", "generateChallenge", "enumerate", "remove"}) |
| setActiveUser(int32_t userId, string storePath) generates (Status status); |
| |
| /** |
| * Begins a secure transaction request, e.g. enroll() or resetLockout(). |
| * |
| * Generates a unique and cryptographically secure random token used to |
| * indicate the start of a secure transaction. generateChallenge() and |
| * revokeChallenge() specify a window where the resulting HAT that is |
| * generated in response to checking the user's PIN/pattern/password |
| * can be used to verify/perform a secure transaction. |
| * |
| * generateChallenge() generates a challenge which must then be wrapped by |
| * gatekeeper after verifying a successful strong authentication attempt, |
| * which generates a Hardware Authentication Token. The challenge prevents |
| * spoofing and replay attacks and ensures that only a transaction backed |
| * by a user authentication (PIN/pattern/password) can proceed. |
| * |
| * The implementation should be tolerant of revokeChallenge() being invoked |
| * after timeout has expired. |
| * |
| * @param challengeTimeoutSec A timeout in seconds, after which the driver |
| * must invalidate the challenge. This is to prevent bugs or crashes in |
| * the system from leaving a challenge enabled indefinitely. |
| * @return result, with its "value" parameter representing a "challenge": a |
| * unique and cryptographically secure random token. |
| */ |
| @callflow(next={"enroll", "revokeChallenge", "setFeature"}) |
| generateChallenge(uint32_t challengeTimeoutSec) |
| generates (OptionalUint64 result); |
| |
| /** |
| * Enrolls a user's face. |
| * |
| * Note that the Hardware Authentication Token must be valid for the |
| * duration of enrollment and thus should be explicitly invalidated by a |
| * call to revokeChallenge() when enrollment is complete, to reduce the |
| * window of opportunity to re-use the challenge and HAT. For example, |
| * Settings calls generateChallenge() once to allow the user to enroll one |
| * or more faces or toggle secure settings without having to re-enter the |
| * PIN/pattern/password. Once the user completes the operation, Settings |
| * invokes revokeChallenge() to close the transaction. If the HAT is expired, |
| * the implementation must invoke onError with UNABLE_TO_PROCESS. |
| * |
| * This method triggers the IBiometricsFaceClientCallback#onEnrollResult() |
| * method. |
| * |
| * @param hat A valid Hardware Authentication Token, generated as a result |
| * of a generateChallenge() challenge being wrapped by the gatekeeper |
| * after a successful strong authentication request. |
| * @param timeoutSec A timeout in seconds, after which this enroll |
| * attempt is cancelled. Note that the framework can continue |
| * enrollment by calling this again with a valid HAT. This timeout is |
| * expected to be used to limit power usage if the device becomes idle |
| * during enrollment. The implementation is expected to send |
| * ERROR_TIMEOUT if this happens. |
| * @param disabledFeatures A list of features to be disabled during |
| * enrollment. Note that all features are enabled by default. |
| * @return status The status of this method call. |
| */ |
| @callflow(next={"cancel", "enroll", "revokeChallenge", "remove"}) |
| enroll(vec<uint8_t> hat, uint32_t timeoutSec, vec<Feature> disabledFeatures) |
| generates (Status status); |
| |
| /** |
| * Finishes the secure transaction by invalidating the challenge generated |
| * by generateChallenge(). |
| * |
| * Clients must call this method once the secure transaction (e.g. enroll |
| * or setFeature) is completed. See generateChallenge(). |
| * |
| * @return status The status of this method call. |
| */ |
| @callflow(next={"authenticate", "setActiveUser", "enumerate", "remove"}) |
| revokeChallenge() generates (Status status); |
| |
| /** |
| * Changes the state of previous enrollment setting. Because this may |
| * decrease security, the user must enter their password before this method |
| * is invoked (see @param HAT). The driver must verify the HAT before |
| * changing any feature state. This method must return ILLEGAL_ARGUMENT if |
| * the HAT or faceId is invalid. This must only be invoked after |
| * setActiveUser() is called. |
| * |
| * Note: In some cases it may not be possible to change the state of this |
| * flag without re-enrolling. For example, if the user didn't provide |
| * attention during the original enrollment. This flag reflects the same |
| * persistent state as the one passed to enroll(). |
| * |
| * Note: This call may block for a short amount of time (few hundred |
| * milliseconds). Clients are expected to invoke this asynchronously if it |
| * takes much longer than the above limit. Also note that the result is |
| * returned solely through Status (and not onError). |
| * |
| * @param feature The feature to be enabled or disabled. |
| * @param enabled True to enable the feature, false to disable. |
| * @param hat A valid Hardware Authentication Token, generated as a result |
| * of getChallenge(). |
| * @param faceId the ID of the enrollment returned by onEnrollResult() for |
| * the feature to update. |
| * @return status The status of this method call. |
| */ |
| setFeature(Feature feature, bool enabled, vec<uint8_t> hat, uint32_t faceId) |
| generates(Status status); |
| |
| /** |
| * Retrieves the current state of the feature. If the faceId is invalid, |
| * the implementation must return ILLEGAL_ARGUMENT. |
| * |
| * @param faceId the ID of the enrollment returned by enroll(). |
| * @return result with the value set to true if the feature is enabled, |
| * false if disabled. |
| */ |
| getFeature(Feature feature, uint32_t faceId) generates (OptionalBool result); |
| |
| /** |
| * Returns an identifier associated with the current face set. |
| * |
| * The authenticator ID must change whenever a new face is enrolled. The |
| * authenticator ID must not be changed when a face is deleted. The |
| * authenticator ID must be an entropy-encoded random number which all |
| * current templates are tied to. The authenticator ID must be immutable |
| * outside of an active enrollment window to prevent replay attacks. |
| * |
| * @return result, with its value parameter representing an |
| * "authenticatorId": an identifier associated to the user's current |
| * face enrollment. |
| */ |
| @callflow(next={"authenticate"}) |
| getAuthenticatorId() generates (OptionalUint64 result); |
| |
| /** |
| * Cancels the current enroll, authenticate, remove, or enumerate operation. |
| * |
| * @return status The status of this method call. |
| */ |
| @callflow(next={"authenticate", "enroll", "enumerate", "remove", |
| "setActiveUser"}) |
| cancel() generates (Status status); |
| |
| /** |
| * Enumerates all face templates associated with the active user. |
| * |
| * The onEnumerate() callback method is invoked once for each face template |
| * found. |
| * |
| * @return status The status of this method call. |
| */ |
| @callflow(next={"remove", "enroll", "authenticate", "setActiveUser"}) |
| enumerate() generates (Status status); |
| |
| /** |
| * Removes a face template or all face templates associated with the active |
| * user. |
| * |
| * This method triggers the IBiometricsFaceClientCallback#onRemoved() method. |
| * |
| * @param faceId The id correpsonding to the face to be removed; or 0 if all |
| * faces are to be removed. |
| * @return status The status of this method call. |
| */ |
| @callflow(next={"enumerate", "authenticate", "cancel", "getAuthenticatorId", |
| "setActiveUser"}) |
| remove(uint32_t faceId) generates (Status status); |
| |
| /** |
| * Authenticates the active user. |
| * |
| * An optional operationId can be specified as a token from the transaction |
| * being authorized. The hardware may enter a standby state during |
| * authentication, where the device is idle to conserve power while |
| * authenticating, e.g. after 3 seconds without finding a face. See |
| * IBiometricsFace#userActivity() for more info. |
| * |
| * @param operationId A non-zero operation id associated with a crypto |
| * object instance; or 0 if not being used. |
| * @return status The status of this method call. |
| */ |
| @callflow(next={"cancel", "generateChallenge", "remove"}) |
| authenticate(uint64_t operationId) generates (Status status); |
| |
| /** |
| * A hint to the HAL to continue looking for faces. |
| * |
| * This method should only be used when the HAL is in the authenticating |
| * or standby state. Using this method when the HAL is not in one of the |
| * mentioned states must return OPERATION_NOT_SUPPORTED. Calling this |
| * method while the HAL is already authenticating may extend the duration |
| * where it's looking for a face. |
| * |
| * @return status The status of this method call. |
| */ |
| userActivity() generates (Status status); |
| |
| /** |
| * Reset lockout for the current user. |
| * |
| * Note: This call may block for a short amount of time (few hundred |
| * milliseconds). Clients are expected to invoke this asynchronously if it |
| * takes much longer than the above limit. |
| * |
| * @param hat A valid Hardware Authentication Token, generated when the |
| * user authenticates with PIN/pattern/pass. When the Hardware |
| * Authentication Token is verified, lockout must be reset and |
| * onLockoutChanged must be called with duration 0. |
| * @return status The status of this method call. |
| */ |
| resetLockout(vec<uint8_t> hat) generates (Status status); |
| }; |