Brian Carlstrom ba1a667b1d Remove need for onActivityResult from KeyChain API
Change-Id: I97bb9db06978f6dc039d22bfee116671d7b3e336
2011-05-25 10:27:46 -07:00

315 lines
12 KiB
Java

/*
* Copyright (C) 2011 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.accounts.Account;
import android.accounts.AccountManager;
import android.accounts.AccountManagerCallback;
import android.accounts.AccountManagerFuture;
import android.accounts.AuthenticatorException;
import android.accounts.OperationCanceledException;
import android.app.Activity;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;
import android.os.Looper;
import android.os.RemoteException;
import java.io.ByteArrayInputStream;
import java.io.Closeable;
import java.io.IOException;
import java.security.KeyFactory;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.cert.Certificate;
import java.security.cert.CertificateException;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;
/**
* @hide
*/
public final class KeyChain {
private static final String TAG = "KeyChain";
/**
* @hide Also used by KeyChainService implementation
*/
public static final String ACCOUNT_TYPE = "com.android.keychain";
/**
* @hide Also used by KeyChainActivity implementation
*/
public static final String EXTRA_RESPONSE = "response";
/**
* Launches an {@code Activity} for the user to select the alias
* for a private key and certificate pair for authentication. The
* selected alias or null will be returned via the
* IKeyChainAliasResponse callback.
*/
public static void choosePrivateKeyAlias(Activity activity, KeyChainAliasResponse response) {
if (activity == null) {
throw new NullPointerException("activity == null");
}
if (response == null) {
throw new NullPointerException("response == null");
}
Intent intent = new Intent("com.android.keychain.CHOOSER");
intent.putExtra(EXTRA_RESPONSE, new AliasResponse(activity, response));
activity.startActivity(intent);
}
private static class AliasResponse extends IKeyChainAliasResponse.Stub {
private final Activity activity;
private final KeyChainAliasResponse keyChainAliasResponse;
private AliasResponse(Activity activity, KeyChainAliasResponse keyChainAliasResponse) {
this.activity = activity;
this.keyChainAliasResponse = keyChainAliasResponse;
}
@Override public void alias(String alias) {
if (alias == null) {
keyChainAliasResponse.alias(null);
return;
}
AccountManager accountManager = AccountManager.get(activity);
accountManager.getAuthToken(getAccount(activity),
alias,
null,
activity,
new AliasAccountManagerCallback(keyChainAliasResponse,
alias),
null);
}
}
private static class AliasAccountManagerCallback implements AccountManagerCallback<Bundle> {
private final KeyChainAliasResponse keyChainAliasResponse;
private final String alias;
private AliasAccountManagerCallback(KeyChainAliasResponse keyChainAliasResponse,
String alias) {
this.keyChainAliasResponse = keyChainAliasResponse;
this.alias = alias;
}
@Override public void run(AccountManagerFuture<Bundle> future) {
Bundle bundle;
try {
bundle = future.getResult();
} catch (OperationCanceledException e) {
keyChainAliasResponse.alias(null);
return;
} catch (IOException e) {
keyChainAliasResponse.alias(null);
return;
} catch (AuthenticatorException e) {
keyChainAliasResponse.alias(null);
return;
}
String authToken = bundle.getString(AccountManager.KEY_AUTHTOKEN);
if (authToken != null) {
keyChainAliasResponse.alias(alias);
} else {
keyChainAliasResponse.alias(null);
}
}
}
/**
* Returns the {@code PrivateKey} for the requested alias, or null
* if no there is no result.
*/
public static PrivateKey getPrivateKey(Context context, String alias)
throws InterruptedException, RemoteException {
if (alias == null) {
throw new NullPointerException("alias == null");
}
KeyChainConnection keyChainConnection = bind(context);
try {
String authToken = authToken(context, alias);
if (authToken == null) {
return null;
}
IKeyChainService keyChainService = keyChainConnection.getService();
byte[] privateKeyBytes = keyChainService.getPrivateKey(alias, authToken);
return toPrivateKey(privateKeyBytes);
} finally {
keyChainConnection.close();
}
}
/**
* Returns the {@code X509Certificate} chain for the requested
* alias, or null if no there is no result.
*/
public static X509Certificate[] getCertificateChain(Context context, String alias)
throws InterruptedException, RemoteException {
if (alias == null) {
throw new NullPointerException("alias == null");
}
KeyChainConnection keyChainConnection = bind(context);
try {
String authToken = authToken(context, alias);
if (authToken == null) {
return null;
}
IKeyChainService keyChainService = keyChainConnection.getService();
byte[] certificateBytes = keyChainService.getCertificate(alias, authToken);
return new X509Certificate[] { toCertificate(certificateBytes) };
} finally {
keyChainConnection.close();
}
}
private static PrivateKey toPrivateKey(byte[] bytes) {
if (bytes == null) {
throw new IllegalArgumentException("bytes == null");
}
try {
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
return keyFactory.generatePrivate(new PKCS8EncodedKeySpec(bytes));
} catch (NoSuchAlgorithmException e) {
throw new AssertionError(e);
} catch (InvalidKeySpecException e) {
throw new AssertionError(e);
}
}
private static X509Certificate toCertificate(byte[] bytes) {
if (bytes == null) {
throw new IllegalArgumentException("bytes == null");
}
try {
CertificateFactory certFactory = CertificateFactory.getInstance("X.509");
Certificate cert = certFactory.generateCertificate(new ByteArrayInputStream(bytes));
return (X509Certificate) cert;
} catch (CertificateException e) {
throw new AssertionError(e);
}
}
private static String authToken(Context context, String alias) {
AccountManager accountManager = AccountManager.get(context);
AccountManagerFuture<Bundle> future = accountManager.getAuthToken(getAccount(context),
alias,
false,
null,
null);
Bundle bundle;
try {
bundle = future.getResult();
} catch (OperationCanceledException e) {
throw new AssertionError(e);
} catch (IOException e) {
// KeyChainAccountAuthenticator doesn't do I/O
throw new AssertionError(e);
} catch (AuthenticatorException e) {
throw new AssertionError(e);
}
Intent intent = bundle.getParcelable(AccountManager.KEY_INTENT);
if (intent != null) {
return null;
}
String authToken = bundle.getString(AccountManager.KEY_AUTHTOKEN);
if (authToken == null) {
throw new AssertionError("Invalid authtoken");
}
return authToken;
}
private static Account getAccount(Context context) {
AccountManager accountManager = AccountManager.get(context);
Account[] accounts = accountManager.getAccountsByType(ACCOUNT_TYPE);
if (accounts.length == 0) {
try {
// Account is created if necessary during binding of the IKeyChainService
bind(context).close();
} catch (InterruptedException e) {
throw new AssertionError(e);
}
accounts = accountManager.getAccountsByType(ACCOUNT_TYPE);
}
return accounts[0];
}
/**
* @hide for reuse by CertInstaller and Settings.
* @see KeyChain#bind
*/
public final static class KeyChainConnection implements Closeable {
private final Context context;
private final ServiceConnection serviceConnection;
private final IKeyChainService service;
private KeyChainConnection(Context context,
ServiceConnection serviceConnection,
IKeyChainService service) {
this.context = context;
this.serviceConnection = serviceConnection;
this.service = service;
}
@Override public void close() {
context.unbindService(serviceConnection);
}
public IKeyChainService getService() {
return service;
}
}
/**
* @hide for reuse by CertInstaller and Settings.
*
* Caller should call unbindService on the result when finished.
*/
public static KeyChainConnection bind(Context context) throws InterruptedException {
if (context == null) {
throw new NullPointerException("context == null");
}
ensureNotOnMainThread(context);
final BlockingQueue<IKeyChainService> q = new LinkedBlockingQueue<IKeyChainService>(1);
ServiceConnection keyChainServiceConnection = new ServiceConnection() {
@Override public void onServiceConnected(ComponentName name, IBinder service) {
try {
q.put(IKeyChainService.Stub.asInterface(service));
} catch (InterruptedException e) {
throw new AssertionError(e);
}
}
@Override public void onServiceDisconnected(ComponentName name) {}
};
boolean isBound = context.bindService(new Intent(IKeyChainService.class.getName()),
keyChainServiceConnection,
Context.BIND_AUTO_CREATE);
if (!isBound) {
throw new AssertionError("could not bind to KeyChainService");
}
return new KeyChainConnection(context, keyChainServiceConnection, q.take());
}
private static void ensureNotOnMainThread(Context context) {
Looper looper = Looper.myLooper();
if (looper != null && looper == context.getMainLooper()) {
throw new IllegalStateException(
"calling this from your main thread can lead to deadlock");
}
}
}