Merge "Adding AIDL and functions for talking to RemoteProvisioner" am: e7f48b9926 (2ace49a7) · Commits · e / os / android_frameworks_base

keystore/java/android/security/GenerateRkpKey.java

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		/*
		* Copyright (C) 2021 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.security;

		import android.content.ComponentName;
		import android.content.Context;
		import android.content.Intent;
		import android.content.ServiceConnection;
		import android.os.IBinder;
		import android.os.RemoteException;

		/**
		* GenerateKey is a helper class to handle interactions between Keystore and the RemoteProvisioner
		* app. There are two cases where Keystore should use this class.
		*
		* (1) : An app generates a new attested key pair, so Keystore calls notifyKeyGenerated to let the
		* RemoteProvisioner app check if the state of the attestation key pool is getting low enough
		* to warrant provisioning more attestation certificates early.
		*
		* (2) : An app attempts to generate a new key pair, but the keystore service discovers it is out of
		* attestation key pairs and cannot provide one for the given application. Keystore can then
		* make a blocking call on notifyEmpty to allow the RemoteProvisioner app to get another
		* attestation certificate chain provisioned.
		*
		* In most cases, the proper usage of (1) should preclude the need for (2).
		*
		* @hide
		*/
		public class GenerateRkpKey {

		private IGenerateRkpKeyService mBinder;
		private Context mContext;

		private ServiceConnection mConnection = new ServiceConnection() {
		@Override
		public void onServiceConnected(ComponentName className, IBinder service) {
		mBinder = IGenerateRkpKeyService.Stub.asInterface(service);
		}

		@Override
		public void onServiceDisconnected(ComponentName className) {
		mBinder = null;
		}
		};

		/**
		* Constructor which takes a Context object.
		*/
		public GenerateRkpKey(Context context) {
		mContext = context;
		}

		/**
		* Fulfills the use case of (2) described in the class documentation. Blocks until the
		* RemoteProvisioner application can get new attestation keys signed by the server.
		*/
		public void notifyEmpty(int securityLevel) throws RemoteException {
		Intent intent = new Intent(IGenerateRkpKeyService.class.getName());
		ComponentName comp = intent.resolveSystemService(mContext.getPackageManager(), 0);
		intent.setComponent(comp);
		if (comp == null \|\| !mContext.bindService(intent, mConnection, Context.BIND_AUTO_CREATE)) {
		throw new RemoteException("Failed to bind to GenerateKeyService");
		}
		if (mBinder != null) {
		mBinder.generateKey(securityLevel);
		}
		mContext.unbindService(mConnection);
		}

		/**
		* FUlfills the use case of (1) described in the class documentation. Non blocking call.
		*/
		public void notifyKeyGenerated(int securityLevel) throws RemoteException {
		Intent intent = new Intent(IGenerateRkpKeyService.class.getName());
		ComponentName comp = intent.resolveSystemService(mContext.getPackageManager(), 0);
		intent.setComponent(comp);
		if (comp == null \|\| !mContext.bindService(intent, mConnection, Context.BIND_AUTO_CREATE)) {
		throw new RemoteException("Failed to bind to GenerateKeyService");
		}
		if (mBinder != null) {
		mBinder.notifyKeyGenerated(securityLevel);
		}
		mContext.unbindService(mConnection);
		}
		}

keystore/java/android/security/GenerateRkpKeyException.java

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		/*
		* Copyright (C) 2021 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.security;

		/**
		* Thrown on problems in attempting to attest to a key using a remotely provisioned key.
		*
		* @hide
		*/
		public class GenerateRkpKeyException extends Exception {

		/**
		* Constructs a new {@code GenerateRkpKeyException}.
		*/
		public GenerateRkpKeyException() {
		}
		}

keystore/java/android/security/IGenerateRkpKeyService.aidl

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		/**
		* Copyright (C) 2021 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.security;

		/**
		* Interface to allow the framework to notify the RemoteProvisioner app when keys are empty. This
		* will be used if Keystore replies with an error code NO_KEYS_AVAILABLE in response to an
		* attestation request. The framework can then synchronously call generateKey() to get more
		* attestation keys generated and signed. Upon return, the caller can be certain an attestation key
		* is available.
		*
		* @hide
		*/
		interface IGenerateRkpKeyService {
		/**
		* Ping the provisioner service to let it know an app generated a key. This may or may not have
		* consumed a remotely provisioned attestation key, so the RemoteProvisioner app should check.
		*/
		oneway void notifyKeyGenerated(in int securityLevel);
		/** Ping the provisioner service to indicate there are no remaining attestation keys left. */
		void generateKey(in int securityLevel);
		}

keystore/java/android/security/keystore2/AndroidKeyStoreKeyPairGeneratorSpi.java

+33 −1

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		@@ -24,6 +24,9 @@ import android.hardware.security.keymint.KeyPurpose;
		import android.hardware.security.keymint.SecurityLevel;
		import android.hardware.security.keymint.Tag;
		import android.os.Build;
		import android.os.RemoteException;
		import android.security.GenerateRkpKey;
		import android.security.GenerateRkpKeyException;
		import android.security.KeyPairGeneratorSpec;
		import android.security.KeyStore;
		import android.security.KeyStore2;
		@@ -520,6 +523,18 @@ public abstract class AndroidKeyStoreKeyPairGeneratorSpi extends KeyPairGenerato

		@Override
		public KeyPair generateKeyPair() {
		try {
		return generateKeyPairHelper();
		} catch (GenerateRkpKeyException e) {
		try {
		return generateKeyPairHelper();
		} catch (GenerateRkpKeyException f) {
		throw new ProviderException("Failed to provision new attestation keys.");
		}
		}
		}

		private KeyPair generateKeyPairHelper() throws GenerateRkpKeyException {
		if (mKeyStore == null \|\| mSpec == null) {
		throw new IllegalStateException("Not initialized");
		}
		@@ -557,13 +572,30 @@ public abstract class AndroidKeyStoreKeyPairGeneratorSpi extends KeyPairGenerato
		AndroidKeyStorePublicKey publicKey =
		AndroidKeyStoreProvider.makeAndroidKeyStorePublicKeyFromKeyEntryResponse(
		descriptor, metadata, iSecurityLevel, mKeymasterAlgorithm);

		GenerateRkpKey keyGen = new GenerateRkpKey(KeyStore.getApplicationContext());
		try {
		if (mSpec.getAttestationChallenge() != null) {
		keyGen.notifyKeyGenerated(securityLevel);
		}
		} catch (RemoteException e) {
		// This is not really an error state, and necessarily does not apply to non RKP
		// systems or hybrid systems where RKP is not currently turned on.
		Log.d(TAG, "Couldn't connect to the RemoteProvisioner backend.");
		}
		success = true;
		return new KeyPair(publicKey, publicKey.getPrivateKey());
		} catch (android.security.KeyStoreException e) {
		switch(e.getErrorCode()) {
		case KeymasterDefs.KM_ERROR_HARDWARE_TYPE_UNAVAILABLE:
		throw new StrongBoxUnavailableException("Failed to generated key pair.", e);
		case ResponseCode.OUT_OF_KEYS:
		GenerateRkpKey keyGen = new GenerateRkpKey(KeyStore.getApplicationContext());
		try {
		keyGen.notifyEmpty(securityLevel);
		} catch (RemoteException f) {
		throw new ProviderException("Failed to talk to RemoteProvisioner", f);
		}
		throw new GenerateRkpKeyException();
		default:
		ProviderException p = new ProviderException("Failed to generate key pair.", e);
		if ((mSpec.getPurposes() & KeyProperties.PURPOSE_WRAP_KEY) != 0) {