| /* |
| * Copyright (C) 2020 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 com.android.server.biometrics; |
| |
| import static android.hardware.biometrics.BiometricAuthenticator.TYPE_CREDENTIAL; |
| import static android.hardware.biometrics.BiometricAuthenticator.TYPE_FACE; |
| import static android.hardware.biometrics.BiometricAuthenticator.TYPE_FINGERPRINT; |
| import static android.hardware.biometrics.BiometricAuthenticator.TYPE_IRIS; |
| import static android.hardware.biometrics.BiometricAuthenticator.TYPE_NONE; |
| |
| import android.annotation.IntDef; |
| import android.annotation.NonNull; |
| import android.app.admin.DevicePolicyManager; |
| import android.app.trust.ITrustManager; |
| import android.hardware.biometrics.BiometricAuthenticator; |
| import android.hardware.biometrics.BiometricManager; |
| import android.hardware.biometrics.PromptInfo; |
| import android.os.RemoteException; |
| import android.util.Pair; |
| import android.util.Slog; |
| |
| import com.android.server.biometrics.sensors.LockoutTracker; |
| |
| import java.lang.annotation.Retention; |
| import java.lang.annotation.RetentionPolicy; |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| /** |
| * Class representing the calling client's request. Additionally, derives/calculates |
| * preliminary info that would be useful in helping serve this request. Note that generating |
| * the PreAuthInfo should not change any sensor state. |
| */ |
| class PreAuthInfo { |
| private static final String TAG = "BiometricService/PreAuthInfo"; |
| |
| static final int AUTHENTICATOR_OK = 1; |
| static final int BIOMETRIC_NO_HARDWARE = 2; |
| static final int BIOMETRIC_DISABLED_BY_DEVICE_POLICY = 3; |
| static final int BIOMETRIC_INSUFFICIENT_STRENGTH = 4; |
| static final int BIOMETRIC_INSUFFICIENT_STRENGTH_AFTER_DOWNGRADE = 5; |
| static final int BIOMETRIC_HARDWARE_NOT_DETECTED = 6; |
| static final int BIOMETRIC_NOT_ENROLLED = 7; |
| static final int BIOMETRIC_NOT_ENABLED_FOR_APPS = 8; |
| static final int CREDENTIAL_NOT_ENROLLED = 9; |
| static final int BIOMETRIC_LOCKOUT_TIMED = 10; |
| static final int BIOMETRIC_LOCKOUT_PERMANENT = 11; |
| @IntDef({AUTHENTICATOR_OK, |
| BIOMETRIC_NO_HARDWARE, |
| BIOMETRIC_DISABLED_BY_DEVICE_POLICY, |
| BIOMETRIC_INSUFFICIENT_STRENGTH, |
| BIOMETRIC_INSUFFICIENT_STRENGTH_AFTER_DOWNGRADE, |
| BIOMETRIC_HARDWARE_NOT_DETECTED, |
| BIOMETRIC_NOT_ENROLLED, |
| BIOMETRIC_NOT_ENABLED_FOR_APPS, |
| CREDENTIAL_NOT_ENROLLED, |
| BIOMETRIC_LOCKOUT_TIMED, |
| BIOMETRIC_LOCKOUT_PERMANENT}) |
| @Retention(RetentionPolicy.SOURCE) |
| @interface AuthenticatorStatus {} |
| |
| private final boolean mBiometricRequested; |
| private final int mBiometricStrengthRequested; |
| |
| final boolean credentialRequested; |
| // Sensors that can be used for this request (e.g. strong enough, enrolled, enabled). |
| final List<BiometricSensor> eligibleSensors; |
| // Sensors that cannot be used for this request. Pair<BiometricSensor, AuthenticatorStatus> |
| final List<Pair<BiometricSensor, Integer>> ineligibleSensors; |
| final boolean credentialAvailable; |
| final boolean confirmationRequested; |
| |
| static PreAuthInfo create(ITrustManager trustManager, |
| DevicePolicyManager devicePolicyManager, |
| BiometricService.SettingObserver settingObserver, |
| List<BiometricSensor> sensors, |
| int userId, PromptInfo promptInfo, String opPackageName, |
| boolean checkDevicePolicyManager) |
| throws RemoteException { |
| |
| final boolean confirmationRequested = promptInfo.isConfirmationRequested(); |
| final boolean biometricRequested = Utils.isBiometricRequested(promptInfo); |
| final int requestedStrength = Utils.getPublicBiometricStrength(promptInfo); |
| final boolean credentialRequested = Utils.isCredentialRequested(promptInfo); |
| |
| final boolean credentialAvailable = trustManager.isDeviceSecure(userId); |
| |
| // Assuming that biometric authenticators are listed in priority-order, the rest of this |
| // function will attempt to find the first authenticator that's as strong or stronger than |
| // the requested strength, available, enrolled, and enabled. The tricky part is returning |
| // the correct error. Error strings that are modality-specific should also respect the |
| // priority-order. |
| |
| final List<BiometricSensor> eligibleSensors = new ArrayList<>(); |
| final List<Pair<BiometricSensor, Integer>> ineligibleSensors = new ArrayList<>(); |
| |
| if (biometricRequested) { |
| for (BiometricSensor sensor : sensors) { |
| |
| @AuthenticatorStatus int status = getStatusForBiometricAuthenticator( |
| devicePolicyManager, settingObserver, sensor, userId, opPackageName, |
| checkDevicePolicyManager, requestedStrength, |
| promptInfo.getAllowedSensorIds()); |
| |
| Slog.d(TAG, "Package: " + opPackageName |
| + " Sensor ID: " + sensor.id |
| + " Modality: " + sensor.modality |
| + " Status: " + status); |
| |
| if (status == AUTHENTICATOR_OK) { |
| eligibleSensors.add(sensor); |
| } else { |
| ineligibleSensors.add(new Pair<>(sensor, status)); |
| } |
| } |
| } |
| |
| return new PreAuthInfo(biometricRequested, requestedStrength, credentialRequested, |
| eligibleSensors, ineligibleSensors, credentialAvailable, confirmationRequested); |
| } |
| |
| /** |
| * Returns the status of the authenticator, with errors returned in a specific priority order. |
| * For example, {@link #BIOMETRIC_INSUFFICIENT_STRENGTH_AFTER_DOWNGRADE} is only returned |
| * if it has enrollments, and is enabled for apps. |
| * |
| * @return @AuthenticatorStatus |
| */ |
| private static @AuthenticatorStatus int getStatusForBiometricAuthenticator( |
| DevicePolicyManager devicePolicyManager, |
| BiometricService.SettingObserver settingObserver, |
| BiometricSensor sensor, int userId, String opPackageName, |
| boolean checkDevicePolicyManager, int requestedStrength, |
| @NonNull List<Integer> requestedSensorIds) { |
| |
| if (!requestedSensorIds.isEmpty() && !requestedSensorIds.contains(sensor.id)) { |
| return BIOMETRIC_NO_HARDWARE; |
| } |
| |
| final boolean wasStrongEnough = |
| Utils.isAtLeastStrength(sensor.oemStrength, requestedStrength); |
| final boolean isStrongEnough = |
| Utils.isAtLeastStrength(sensor.getCurrentStrength(), requestedStrength); |
| |
| if (wasStrongEnough && !isStrongEnough) { |
| return BIOMETRIC_INSUFFICIENT_STRENGTH_AFTER_DOWNGRADE; |
| } else if (!wasStrongEnough) { |
| return BIOMETRIC_INSUFFICIENT_STRENGTH; |
| } |
| |
| try { |
| if (!sensor.impl.isHardwareDetected(opPackageName)) { |
| return BIOMETRIC_HARDWARE_NOT_DETECTED; |
| } |
| |
| if (!sensor.impl.hasEnrolledTemplates(userId, opPackageName)) { |
| return BIOMETRIC_NOT_ENROLLED; |
| } |
| |
| final @LockoutTracker.LockoutMode int lockoutMode = |
| sensor.impl.getLockoutModeForUser(userId); |
| if (lockoutMode == LockoutTracker.LOCKOUT_TIMED) { |
| return BIOMETRIC_LOCKOUT_TIMED; |
| } else if (lockoutMode == LockoutTracker.LOCKOUT_PERMANENT) { |
| return BIOMETRIC_LOCKOUT_PERMANENT; |
| } |
| } catch (RemoteException e) { |
| return BIOMETRIC_HARDWARE_NOT_DETECTED; |
| } |
| |
| if (!isEnabledForApp(settingObserver, sensor.modality, userId)) { |
| return BIOMETRIC_NOT_ENABLED_FOR_APPS; |
| } |
| |
| if (checkDevicePolicyManager) { |
| if (isBiometricDisabledByDevicePolicy(devicePolicyManager, sensor.modality, userId)) { |
| return BIOMETRIC_DISABLED_BY_DEVICE_POLICY; |
| } |
| } |
| |
| return AUTHENTICATOR_OK; |
| } |
| |
| private static boolean isEnabledForApp(BiometricService.SettingObserver settingObserver, |
| @BiometricAuthenticator.Modality int modality, int userId) { |
| return settingObserver.getEnabledForApps(userId); |
| } |
| |
| private static boolean isBiometricDisabledByDevicePolicy( |
| DevicePolicyManager devicePolicyManager, @BiometricAuthenticator.Modality int modality, |
| int effectiveUserId) { |
| final int biometricToCheck = mapModalityToDevicePolicyType(modality); |
| if (biometricToCheck == DevicePolicyManager.KEYGUARD_DISABLE_FEATURES_NONE) { |
| throw new IllegalStateException("Modality unknown to devicePolicyManager: " + modality); |
| } |
| final int devicePolicyDisabledFeatures = |
| devicePolicyManager.getKeyguardDisabledFeatures(null, effectiveUserId); |
| final boolean isBiometricDisabled = |
| (biometricToCheck & devicePolicyDisabledFeatures) != 0; |
| Slog.w(TAG, "isBiometricDisabledByDevicePolicy(" + modality + "," + effectiveUserId |
| + ")=" + isBiometricDisabled); |
| return isBiometricDisabled; |
| } |
| |
| /** |
| * @param modality one of {@link BiometricAuthenticator#TYPE_FINGERPRINT}, |
| * {@link BiometricAuthenticator#TYPE_IRIS} or {@link BiometricAuthenticator#TYPE_FACE} |
| * @return |
| */ |
| private static int mapModalityToDevicePolicyType(int modality) { |
| switch (modality) { |
| case TYPE_FINGERPRINT: |
| return DevicePolicyManager.KEYGUARD_DISABLE_FINGERPRINT; |
| case TYPE_IRIS: |
| return DevicePolicyManager.KEYGUARD_DISABLE_IRIS; |
| case TYPE_FACE: |
| return DevicePolicyManager.KEYGUARD_DISABLE_FACE; |
| default: |
| Slog.e(TAG, "Error modality=" + modality); |
| return DevicePolicyManager.KEYGUARD_DISABLE_FEATURES_NONE; |
| } |
| } |
| |
| private PreAuthInfo(boolean biometricRequested, int biometricStrengthRequested, |
| boolean credentialRequested, List<BiometricSensor> eligibleSensors, |
| List<Pair<BiometricSensor, Integer>> ineligibleSensors, boolean credentialAvailable, |
| boolean confirmationRequested) { |
| mBiometricRequested = biometricRequested; |
| mBiometricStrengthRequested = biometricStrengthRequested; |
| this.credentialRequested = credentialRequested; |
| |
| this.eligibleSensors = eligibleSensors; |
| this.ineligibleSensors = ineligibleSensors; |
| this.credentialAvailable = credentialAvailable; |
| this.confirmationRequested = confirmationRequested; |
| } |
| |
| private Pair<BiometricSensor, Integer> calculateErrorByPriority() { |
| // If the caller requested STRONG, and the device contains both STRONG and non-STRONG |
| // sensors, prioritize BIOMETRIC_NOT_ENROLLED over the weak sensor's |
| // BIOMETRIC_INSUFFICIENT_STRENGTH error. Pretty sure we can always prioritize |
| // BIOMETRIC_NOT_ENROLLED over any other error (unless of course its calculation is |
| // wrong, in which case we should fix that instead). |
| for (Pair<BiometricSensor, Integer> pair : ineligibleSensors) { |
| if (pair.second == BIOMETRIC_NOT_ENROLLED) { |
| return pair; |
| } |
| } |
| |
| return ineligibleSensors.get(0); |
| } |
| |
| /** |
| * With {@link PreAuthInfo} generated with the requested authenticators from the public API |
| * surface, combined with the actual sensor/credential and user/system settings, calculate the |
| * internal {@link AuthenticatorStatus} that should be returned to the client. Note that this |
| * will need to be converted into the public API constant. |
| * @return Pair<Modality, Error> with error being the internal {@link AuthenticatorStatus} code |
| */ |
| private Pair<Integer, Integer> getInternalStatus() { |
| @AuthenticatorStatus final int status; |
| @BiometricAuthenticator.Modality int modality = TYPE_NONE; |
| if (mBiometricRequested && credentialRequested) { |
| if (credentialAvailable || !eligibleSensors.isEmpty()) { |
| status = AUTHENTICATOR_OK; |
| if (credentialAvailable) { |
| modality |= TYPE_CREDENTIAL; |
| } |
| for (BiometricSensor sensor : eligibleSensors) { |
| modality |= sensor.modality; |
| } |
| } else { |
| // Pick the first sensor error if it exists |
| if (!ineligibleSensors.isEmpty()) { |
| final Pair<BiometricSensor, Integer> pair = calculateErrorByPriority(); |
| modality |= pair.first.modality; |
| status = pair.second; |
| } else { |
| modality |= TYPE_CREDENTIAL; |
| status = CREDENTIAL_NOT_ENROLLED; |
| } |
| } |
| } else if (mBiometricRequested) { |
| if (!eligibleSensors.isEmpty()) { |
| status = AUTHENTICATOR_OK; |
| for (BiometricSensor sensor : eligibleSensors) { |
| modality |= sensor.modality; |
| } |
| } else { |
| // Pick the first sensor error if it exists |
| if (!ineligibleSensors.isEmpty()) { |
| final Pair<BiometricSensor, Integer> pair = calculateErrorByPriority(); |
| modality |= pair.first.modality; |
| status = pair.second; |
| } else { |
| modality |= TYPE_NONE; |
| status = BIOMETRIC_NO_HARDWARE; |
| } |
| } |
| } else if (credentialRequested) { |
| modality |= TYPE_CREDENTIAL; |
| status = credentialAvailable ? AUTHENTICATOR_OK : CREDENTIAL_NOT_ENROLLED; |
| } else { |
| // This should not be possible via the public API surface and is here mainly for |
| // "correctness". An exception should have been thrown before getting here. |
| Slog.e(TAG, "No authenticators requested"); |
| status = BIOMETRIC_NO_HARDWARE; |
| } |
| |
| Slog.d(TAG, "getCanAuthenticateInternal Modality: " + modality |
| + " AuthenticatorStatus: " + status); |
| return new Pair<>(modality, status); |
| } |
| |
| /** |
| * @return public BiometricManager result for the current request. |
| */ |
| @BiometricManager.BiometricError int getCanAuthenticateResult() { |
| // TODO: Convert this directly |
| return Utils.biometricConstantsToBiometricManager( |
| Utils.authenticatorStatusToBiometricConstant( |
| getInternalStatus().second)); |
| } |
| |
| /** |
| * For the given request, generate the appropriate reason why authentication cannot be started. |
| * Note that for some errors, modality is intentionally cleared. |
| * @return Pair<Modality, Error> with modality being filtered if necessary, and error |
| * being one of the public {@link android.hardware.biometrics.BiometricConstants} codes. |
| */ |
| Pair<Integer, Integer> getPreAuthenticateStatus() { |
| final Pair<Integer, Integer> internalStatus = getInternalStatus(); |
| |
| final int publicError = Utils.authenticatorStatusToBiometricConstant(internalStatus.second); |
| int modality = internalStatus.first; |
| switch (internalStatus.second) { |
| case AUTHENTICATOR_OK: |
| case BIOMETRIC_NO_HARDWARE: |
| case BIOMETRIC_INSUFFICIENT_STRENGTH_AFTER_DOWNGRADE: |
| case BIOMETRIC_HARDWARE_NOT_DETECTED: |
| case BIOMETRIC_NOT_ENROLLED: |
| case CREDENTIAL_NOT_ENROLLED: |
| case BIOMETRIC_LOCKOUT_TIMED: |
| case BIOMETRIC_LOCKOUT_PERMANENT: |
| break; |
| |
| case BIOMETRIC_DISABLED_BY_DEVICE_POLICY: |
| case BIOMETRIC_INSUFFICIENT_STRENGTH: |
| case BIOMETRIC_NOT_ENABLED_FOR_APPS: |
| default: |
| modality = TYPE_NONE; |
| break; |
| } |
| |
| return new Pair<>(modality, publicError); |
| } |
| |
| /** |
| * @return true if SystemUI should show the credential UI. |
| */ |
| boolean shouldShowCredential() { |
| return credentialRequested && credentialAvailable; |
| } |
| |
| /** |
| * @return bitmask representing the modalities that are running or could be running for the |
| * current session. |
| */ |
| @BiometricAuthenticator.Modality int getEligibleModalities() { |
| @BiometricAuthenticator.Modality int modalities = 0; |
| for (BiometricSensor sensor : eligibleSensors) { |
| modalities |= sensor.modality; |
| } |
| |
| if (credentialRequested && credentialAvailable) { |
| modalities |= TYPE_CREDENTIAL; |
| } |
| return modalities; |
| } |
| |
| int numSensorsWaitingForCookie() { |
| int numWaiting = 0; |
| for (BiometricSensor sensor : eligibleSensors) { |
| if (sensor.getSensorState() == BiometricSensor.STATE_WAITING_FOR_COOKIE) { |
| Slog.d(TAG, "Sensor ID: " + sensor.id |
| + " Waiting for cookie: " + sensor.getCookie()); |
| numWaiting++; |
| } |
| } |
| return numWaiting; |
| } |
| |
| @Override |
| public String toString() { |
| StringBuilder string = new StringBuilder( |
| "BiometricRequested: " + mBiometricRequested |
| + ", StrengthRequested: " + mBiometricStrengthRequested |
| + ", CredentialRequested: " + credentialRequested); |
| string.append(", Eligible:{"); |
| for (BiometricSensor sensor: eligibleSensors) { |
| string.append(sensor.id).append(" "); |
| } |
| string.append("}"); |
| |
| string.append(", Ineligible:{"); |
| for (Pair<BiometricSensor, Integer> ineligible : ineligibleSensors) { |
| string.append(ineligible.first).append(":").append(ineligible.second).append(" "); |
| } |
| string.append("}"); |
| |
| string.append(", CredentialAvailable: ").append(credentialAvailable); |
| string.append(", "); |
| return string.toString(); |
| } |
| } |
