| /* |
| * 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 static android.security.Credentials.ACTION_MANAGE_CREDENTIALS; |
| |
| import android.Manifest; |
| import android.annotation.NonNull; |
| import android.annotation.Nullable; |
| import android.annotation.RequiresPermission; |
| import android.annotation.SdkConstant; |
| import android.annotation.SdkConstant.SdkConstantType; |
| import android.annotation.SystemApi; |
| import android.annotation.TestApi; |
| import android.annotation.WorkerThread; |
| import android.app.Activity; |
| import android.app.PendingIntent; |
| import android.app.Service; |
| import android.content.ComponentName; |
| import android.content.Context; |
| import android.content.Intent; |
| import android.content.ServiceConnection; |
| import android.net.Uri; |
| import android.os.Binder; |
| import android.os.Handler; |
| import android.os.IBinder; |
| import android.os.Looper; |
| import android.os.Process; |
| import android.os.RemoteException; |
| import android.os.UserHandle; |
| import android.os.UserManager; |
| import android.security.keystore.AndroidKeyStoreProvider; |
| import android.security.keystore.KeyPermanentlyInvalidatedException; |
| import android.security.keystore.KeyProperties; |
| import android.system.keystore2.Domain; |
| import android.system.keystore2.KeyDescriptor; |
| import android.util.Log; |
| |
| import com.android.org.conscrypt.TrustedCertificateStore; |
| |
| import java.io.ByteArrayInputStream; |
| import java.io.Closeable; |
| import java.io.Serializable; |
| import java.security.KeyPair; |
| import java.security.Principal; |
| import java.security.PrivateKey; |
| import java.security.UnrecoverableKeyException; |
| import java.security.cert.Certificate; |
| import java.security.cert.CertificateException; |
| import java.security.cert.CertificateFactory; |
| import java.security.cert.X509Certificate; |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.List; |
| import java.util.Locale; |
| import java.util.concurrent.CountDownLatch; |
| import java.util.concurrent.atomic.AtomicReference; |
| |
| import javax.security.auth.x500.X500Principal; |
| |
| /** |
| * The {@code KeyChain} class provides access to private keys and |
| * their corresponding certificate chains in credential storage. |
| * |
| * <p>Applications accessing the {@code KeyChain} normally go through |
| * these steps: |
| * |
| * <ol> |
| * |
| * <li>Receive a callback from an {@link javax.net.ssl.X509KeyManager |
| * X509KeyManager} that a private key is requested. |
| * |
| * <li>Call {@link #choosePrivateKeyAlias |
| * choosePrivateKeyAlias} to allow the user to select from a |
| * list of currently available private keys and corresponding |
| * certificate chains. The chosen alias will be returned by the |
| * callback {@link KeyChainAliasCallback#alias}, or null if no private |
| * key is available or the user cancels the request. |
| * |
| * <li>Call {@link #getPrivateKey} and {@link #getCertificateChain} to |
| * retrieve the credentials to return to the corresponding {@link |
| * javax.net.ssl.X509KeyManager} callbacks. |
| * |
| * </ol> |
| * |
| * <p>An application may remember the value of a selected alias to |
| * avoid prompting the user with {@link #choosePrivateKeyAlias |
| * choosePrivateKeyAlias} on subsequent connections. If the alias is |
| * no longer valid, null will be returned on lookups using that value |
| * |
| * <p>An application can request the installation of private keys and |
| * certificates via the {@code Intent} provided by {@link |
| * #createInstallIntent}. Private keys installed via this {@code |
| * Intent} will be accessible via {@link #choosePrivateKeyAlias} while |
| * Certificate Authority (CA) certificates will be trusted by all |
| * applications through the default {@code X509TrustManager}. |
| */ |
| // TODO reference intent for credential installation when public |
| public final class KeyChain { |
| |
| /** |
| * @hide |
| */ |
| public static final String LOG = "KeyChain"; |
| |
| /** |
| * @hide Also used by KeyChainService implementation |
| */ |
| public static final String ACCOUNT_TYPE = "com.android.keychain"; |
| |
| /** |
| * Package name for KeyChain chooser. |
| */ |
| private static final String KEYCHAIN_PACKAGE = "com.android.keychain"; |
| |
| /** |
| * Action to bring up the KeyChainActivity |
| */ |
| private static final String ACTION_CHOOSER = "com.android.keychain.CHOOSER"; |
| |
| /** |
| * Package name for the Certificate Installer. |
| */ |
| private static final String CERT_INSTALLER_PACKAGE = "com.android.certinstaller"; |
| |
| /** |
| * Package name for Settings. |
| */ |
| private static final String SETTINGS_PACKAGE = "com.android.settings"; |
| |
| /** |
| * Extra for use with {@link #ACTION_CHOOSER} |
| * @hide Also used by KeyChainActivity implementation |
| */ |
| public static final String EXTRA_RESPONSE = "response"; |
| |
| /** |
| * Extra for use with {@link #ACTION_CHOOSER} |
| * @hide Also used by KeyChainActivity implementation |
| */ |
| public static final String EXTRA_URI = "uri"; |
| |
| /** |
| * Extra for use with {@link #ACTION_CHOOSER} |
| * @hide Also used by KeyChainActivity implementation |
| */ |
| public static final String EXTRA_ALIAS = "alias"; |
| |
| /** |
| * Extra for use with {@link #ACTION_CHOOSER} |
| * @hide Also used by KeyChainActivity implementation |
| */ |
| public static final String EXTRA_SENDER = "sender"; |
| |
| /** |
| * Extra for use with {@link #ACTION_CHOOSER} |
| * @hide Also used by KeyChainActivity implementation |
| */ |
| public static final String EXTRA_KEY_TYPES = "key_types"; |
| |
| /** |
| * Extra for use with {@link #ACTION_CHOOSER} |
| * @hide Also used by KeyChainActivity implementation |
| */ |
| public static final String EXTRA_ISSUERS = "issuers"; |
| |
| /** |
| * Action to bring up the CertInstaller. |
| */ |
| private static final String ACTION_INSTALL = "android.credentials.INSTALL"; |
| |
| /** |
| * Optional extra to specify a {@code String} credential name on |
| * the {@code Intent} returned by {@link #createInstallIntent}. |
| */ |
| // Compatible with old com.android.certinstaller.CredentialHelper.CERT_NAME_KEY |
| public static final String EXTRA_NAME = "name"; |
| |
| /** |
| * Optional extra to specify an X.509 certificate to install on |
| * the {@code Intent} returned by {@link #createInstallIntent}. |
| * The extra value should be a PEM or ASN.1 DER encoded {@code |
| * byte[]}. An {@link X509Certificate} can be converted to DER |
| * encoded bytes with {@link X509Certificate#getEncoded}. |
| * |
| * <p>{@link #EXTRA_NAME} may be used to provide a default alias |
| * name for the installed certificate. |
| */ |
| // Compatible with old android.security.Credentials.CERTIFICATE |
| public static final String EXTRA_CERTIFICATE = "CERT"; |
| |
| /** |
| * Optional extra for use with the {@code Intent} returned by |
| * {@link #createInstallIntent} to specify a PKCS#12 key store to |
| * install. The extra value should be a {@code byte[]}. The bytes |
| * may come from an external source or be generated with {@link |
| * java.security.KeyStore#store} on a "PKCS12" instance. |
| * |
| * <p>The user will be prompted for the password to load the key store. |
| * |
| * <p>The key store will be scanned for {@link |
| * java.security.KeyStore.PrivateKeyEntry} entries and both the |
| * private key and associated certificate chain will be installed. |
| * |
| * <p>{@link #EXTRA_NAME} may be used to provide a default alias |
| * name for the installed credentials. |
| */ |
| // Compatible with old android.security.Credentials.PKCS12 |
| public static final String EXTRA_PKCS12 = "PKCS12"; |
| |
| /** |
| * Extra used by {@link #createManageCredentialsIntent(AppUriAuthenticationPolicy)} to specify |
| * the authentication policy of the credential management app. |
| * |
| * <p>The authentication policy declares which alias for a private key and certificate pair |
| * should be used for authentication, given a list of apps and URIs. |
| * |
| * <p>The extra value should be a {@link AppUriAuthenticationPolicy}. |
| * |
| * @hide |
| */ |
| public static final String EXTRA_AUTHENTICATION_POLICY = |
| "android.security.extra.AUTHENTICATION_POLICY"; |
| |
| /** |
| * Broadcast Action: Indicates the trusted storage has changed. Sent when |
| * one of this happens: |
| * |
| * <ul> |
| * <li>a new CA is added, |
| * <li>an existing CA is removed or disabled, |
| * <li>a disabled CA is enabled, |
| * <li>trusted storage is reset (all user certs are cleared), |
| * <li>when permission to access a private key is changed. |
| * </ul> |
| * |
| * @deprecated Use {@link #ACTION_KEYCHAIN_CHANGED}, {@link #ACTION_TRUST_STORE_CHANGED} or |
| * {@link #ACTION_KEY_ACCESS_CHANGED}. Apps that target a version higher than |
| * {@link android.os.Build.VERSION_CODES#N_MR1} will only receive this broadcast if they |
| * register for it at runtime. |
| */ |
| @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION) |
| public static final String ACTION_STORAGE_CHANGED = "android.security.STORAGE_CHANGED"; |
| |
| /** |
| * Broadcast Action: Indicates the contents of the keychain has changed. Sent when a KeyChain |
| * entry is added, modified or removed. |
| */ |
| @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION) |
| public static final String ACTION_KEYCHAIN_CHANGED = "android.security.action.KEYCHAIN_CHANGED"; |
| |
| /** |
| * Broadcast Action: Indicates the contents of the trusted certificate store has changed. Sent |
| * when one the following occurs: |
| * |
| * <ul> |
| * <li>A pre-installed CA is disabled or re-enabled</li> |
| * <li>A CA is added or removed from the trust store</li> |
| * </ul> |
| */ |
| @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION) |
| public static final String ACTION_TRUST_STORE_CHANGED = |
| "android.security.action.TRUST_STORE_CHANGED"; |
| |
| /** |
| * Broadcast Action: Indicates that the access permissions for a private key have changed. |
| * |
| */ |
| @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION) |
| public static final String ACTION_KEY_ACCESS_CHANGED = |
| "android.security.action.KEY_ACCESS_CHANGED"; |
| |
| /** |
| * Used as a String extra field in {@link #ACTION_KEY_ACCESS_CHANGED} to supply the alias of |
| * the key. |
| */ |
| public static final String EXTRA_KEY_ALIAS = "android.security.extra.KEY_ALIAS"; |
| |
| /** |
| * Used as a boolean extra field in {@link #ACTION_KEY_ACCESS_CHANGED} to supply if the key is |
| * accessible to the application. |
| */ |
| public static final String EXTRA_KEY_ACCESSIBLE = "android.security.extra.KEY_ACCESSIBLE"; |
| |
| /** |
| * Indicates that a call to {@link #generateKeyPair} was successful. |
| * @hide |
| */ |
| public static final int KEY_GEN_SUCCESS = 0; |
| |
| /** |
| * An alias was missing from the key specifications when calling {@link #generateKeyPair}. |
| * @hide |
| */ |
| public static final int KEY_GEN_MISSING_ALIAS = 1; |
| |
| /** |
| * A key attestation challenge was provided to {@link #generateKeyPair}, but it shouldn't |
| * have been provided. |
| * @hide |
| */ |
| public static final int KEY_GEN_SUPERFLUOUS_ATTESTATION_CHALLENGE = 2; |
| |
| /** |
| * Algorithm not supported by {@link #generateKeyPair} |
| * @hide |
| */ |
| public static final int KEY_GEN_NO_SUCH_ALGORITHM = 3; |
| |
| /** |
| * Invalid algorithm parameters when calling {@link #generateKeyPair} |
| * @hide |
| */ |
| public static final int KEY_GEN_INVALID_ALGORITHM_PARAMETERS = 4; |
| |
| /** |
| * Keystore is not available when calling {@link #generateKeyPair} |
| * @hide |
| */ |
| public static final int KEY_GEN_NO_KEYSTORE_PROVIDER = 5; |
| |
| /** |
| * StrongBox unavailable when calling {@link #generateKeyPair} |
| * @hide |
| */ |
| public static final int KEY_GEN_STRONGBOX_UNAVAILABLE = 6; |
| |
| /** |
| * General failure while calling {@link #generateKeyPair} |
| * @hide |
| */ |
| public static final int KEY_GEN_FAILURE = 7; |
| |
| /** |
| * Successful call to {@link #attestKey} |
| * @hide |
| */ |
| public static final int KEY_ATTESTATION_SUCCESS = 0; |
| |
| /** |
| * Attestation challenge missing when calling {@link #attestKey} |
| * @hide |
| */ |
| public static final int KEY_ATTESTATION_MISSING_CHALLENGE = 1; |
| |
| /** |
| * The caller requested Device ID attestation when calling {@link #attestKey}, but has no |
| * permissions to get device identifiers. |
| * @hide |
| */ |
| public static final int KEY_ATTESTATION_CANNOT_COLLECT_DATA = 2; |
| |
| /** |
| * The underlying hardware does not support Device ID attestation or cannot attest to the |
| * identifiers that are stored on the device. This indicates permanent inability |
| * to get attestation records on the device. |
| * @hide |
| */ |
| public static final int KEY_ATTESTATION_CANNOT_ATTEST_IDS = 3; |
| |
| /** |
| * General failure when calling {@link #attestKey} |
| * @hide |
| */ |
| public static final int KEY_ATTESTATION_FAILURE = 4; |
| |
| /** |
| * Used by DPC or delegated app in |
| * {@link android.app.admin.DeviceAdminReceiver#onChoosePrivateKeyAlias} or |
| * {@link android.app.admin.DelegatedAdminReceiver#onChoosePrivateKeyAlias} to identify that |
| * the requesting app is not granted access to any key, and nor will the user be able to grant |
| * access manually. |
| */ |
| public static final String KEY_ALIAS_SELECTION_DENIED = |
| "android:alias-selection-denied"; |
| |
| /** |
| * Returns an {@code Intent} that can be used for credential |
| * installation. The intent may be used without any extras, in |
| * which case the user will be able to install credentials from |
| * their own source. |
| * |
| * <p>Alternatively, {@link #EXTRA_CERTIFICATE} or {@link |
| * #EXTRA_PKCS12} maybe used to specify the bytes of an X.509 |
| * certificate or a PKCS#12 key store for installation. These |
| * extras may be combined with {@link #EXTRA_NAME} to provide a |
| * default alias name for credentials being installed. |
| * |
| * <p>When used with {@link Activity#startActivityForResult}, |
| * {@link Activity#RESULT_OK} will be returned if a credential was |
| * successfully installed, otherwise {@link |
| * Activity#RESULT_CANCELED} will be returned. |
| * |
| * <p>Starting from {@link android.os.Build.VERSION_CODES#R}, the intent returned by this |
| * method cannot be used for installing CA certificates. Since CA certificates can only be |
| * installed via Settings, the app should provide the user with a file containing the |
| * CA certificate. One way to do this would be to use the {@link android.provider.MediaStore} |
| * API to write the certificate to the {@link android.provider.MediaStore.Downloads} |
| * collection. |
| */ |
| @NonNull |
| public static Intent createInstallIntent() { |
| Intent intent = new Intent(ACTION_INSTALL); |
| intent.setClassName(CERT_INSTALLER_PACKAGE, |
| "com.android.certinstaller.CertInstallerMain"); |
| return intent; |
| } |
| |
| /** |
| * Returns an {@code Intent} that should be used by an app to request to manage the user's |
| * credentials. This is limited to unmanaged devices. The authentication policy must be |
| * provided to be able to make this request successfully. |
| * |
| * <p> This intent should be started using {@link Activity#startActivityForResult(Intent, int)} |
| * to verify whether the request was successful and whether the user accepted or denied the |
| * request. If the user successfully receives and accepts the request, the result code will be |
| * {@link Activity#RESULT_OK}, otherwise the result code will be |
| * {@link Activity#RESULT_CANCELED}. |
| * |
| * <p> {@link KeyChain#isCredentialManagementApp(Context)} should be used to determine whether |
| * an app is already the credential management app. |
| * |
| * @param policy The authentication policy determines which alias for a private key and |
| * certificate pair should be used for authentication. |
| */ |
| @NonNull |
| public static Intent createManageCredentialsIntent(@NonNull AppUriAuthenticationPolicy policy) { |
| Intent intent = new Intent(ACTION_MANAGE_CREDENTIALS); |
| intent.setComponent(ComponentName.createRelative(SETTINGS_PACKAGE, |
| ".security.RequestManageCredentials")); |
| intent.putExtra(EXTRA_AUTHENTICATION_POLICY, policy); |
| return intent; |
| } |
| |
| /** |
| * 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 |
| * KeyChainAliasCallback callback. |
| * |
| * <p>A device policy controller (as a device or profile owner) can |
| * intercept the request before the activity is shown, to pick a |
| * specific private key alias by implementing |
| * {@link android.app.admin.DeviceAdminReceiver#onChoosePrivateKeyAlias |
| * onChoosePrivateKeyAlias}. |
| * |
| * <p>{@code keyTypes} and {@code issuers} may be used to |
| * narrow down suggested choices to the user. If either {@code keyTypes} |
| * or {@code issuers} is specified and non-empty, and there are no |
| * matching certificates in the KeyChain, then the certificate |
| * selection prompt would be suppressed entirely. |
| * |
| * <p>{@code host} and {@code port} may be used to give the user |
| * more context about the server requesting the credentials. |
| * |
| * <p>{@code alias} allows the caller to preselect an existing |
| * alias which will still be subject to user confirmation. |
| * |
| * @param activity The {@link Activity} context to use for |
| * launching the new sub-Activity to prompt the user to select |
| * a private key; used only to call startActivity(); must not |
| * be null. |
| * @param response Callback to invoke when the request completes; |
| * must not be null. |
| * @param keyTypes The acceptable types of asymmetric keys such as |
| * "RSA", "EC" or null. |
| * @param issuers The acceptable certificate issuers for the |
| * certificate matching the private key, or null. |
| * @param host The host name of the server requesting the |
| * certificate, or null if unavailable. |
| * @param port The port number of the server requesting the |
| * certificate, or -1 if unavailable. |
| * @param alias The alias to preselect if available, or null if |
| * unavailable. |
| */ |
| public static void choosePrivateKeyAlias(@NonNull Activity activity, |
| @NonNull KeyChainAliasCallback response, |
| @Nullable @KeyProperties.KeyAlgorithmEnum String[] keyTypes, |
| @Nullable Principal[] issuers, |
| @Nullable String host, int port, @Nullable String alias) { |
| Uri uri = null; |
| if (host != null) { |
| uri = new Uri.Builder() |
| .authority(host + (port != -1 ? ":" + port : "")) |
| .build(); |
| } |
| choosePrivateKeyAlias(activity, response, keyTypes, issuers, uri, alias); |
| } |
| |
| /** |
| * 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 |
| * KeyChainAliasCallback callback. |
| * |
| * <p>A device policy controller (as a device or profile owner) can |
| * intercept the request before the activity is shown, to pick a |
| * specific private key alias by implementing |
| * {@link android.app.admin.DeviceAdminReceiver#onChoosePrivateKeyAlias |
| * onChoosePrivateKeyAlias}. |
| * |
| * <p>{@code keyTypes} and {@code issuers} may be used to |
| * narrow down suggested choices to the user. If either {@code keyTypes} |
| * or {@code issuers} is specified and non-empty, and there are no |
| * matching certificates in the KeyChain, then the certificate |
| * selection prompt would be suppressed entirely. |
| * |
| * <p>{@code uri} may be used to give the user more context about |
| * the server requesting the credentials. |
| * |
| * <p>{@code alias} allows the caller to preselect an existing |
| * alias which will still be subject to user confirmation. |
| * |
| * @param activity The {@link Activity} context to use for |
| * launching the new sub-Activity to prompt the user to select |
| * a private key; used only to call startActivity(); must not |
| * be null. |
| * @param response Callback to invoke when the request completes; |
| * must not be null. |
| * @param keyTypes The acceptable types of asymmetric keys such as |
| * "RSA", "EC" or null. |
| * @param issuers The acceptable certificate issuers for the |
| * certificate matching the private key, or null. |
| * @param uri The full URI the server is requesting the certificate |
| * for, or null if unavailable. |
| * @param alias The alias to preselect if available, or null if |
| * unavailable. |
| * @throws IllegalArgumentException if the specified issuers are not |
| * of type {@code X500Principal}. |
| */ |
| public static void choosePrivateKeyAlias(@NonNull Activity activity, |
| @NonNull KeyChainAliasCallback response, |
| @Nullable @KeyProperties.KeyAlgorithmEnum String[] keyTypes, |
| @Nullable Principal[] issuers, |
| @Nullable Uri uri, @Nullable String alias) { |
| /* |
| * Specifying keyTypes excludes certificates with different key types |
| * from the list of certificates presented to the user. |
| * In practice today, most servers would require RSA or EC |
| * certificates. |
| * |
| * Specifying issuers narrows down the list by filtering out |
| * certificates with issuers which are not matching the provided ones. |
| * This has been reported to Chrome several times (crbug.com/731769). |
| * There's no concrete description on what to do when the client has no |
| * certificates that match the provided issuers. |
| * To be conservative, Android will not present the user with any |
| * certificates to choose from. |
| * If the list of issuers is empty then the client may send any |
| * certificate, see: |
| * https://tools.ietf.org/html/rfc5246#section-7.4.4 |
| */ |
| if (activity == null) { |
| throw new NullPointerException("activity == null"); |
| } |
| if (response == null) { |
| throw new NullPointerException("response == null"); |
| } |
| Intent intent = new Intent(ACTION_CHOOSER); |
| intent.setPackage(KEYCHAIN_PACKAGE); |
| intent.putExtra(EXTRA_RESPONSE, new AliasResponse(response)); |
| intent.putExtra(EXTRA_URI, uri); |
| intent.putExtra(EXTRA_ALIAS, alias); |
| intent.putExtra(EXTRA_KEY_TYPES, keyTypes); |
| ArrayList<byte[]> issuersList = new ArrayList(); |
| if (issuers != null) { |
| for (Principal issuer: issuers) { |
| // In a TLS client context (like Chrome), issuers would only |
| // be specified as X500Principals. No other use cases for |
| // specifying principals have been brought up. Under these |
| // circumstances, only allow issuers specified as |
| // X500Principals. |
| if (!(issuer instanceof X500Principal)) { |
| throw new IllegalArgumentException(String.format( |
| "Issuer %s is of type %s, not X500Principal", |
| issuer.toString(), issuer.getClass())); |
| } |
| // Pass the DER-encoded issuer as that's the most accurate |
| // representation and what is sent over the wire. |
| issuersList.add(((X500Principal) issuer).getEncoded()); |
| } |
| } |
| intent.putExtra(EXTRA_ISSUERS, (Serializable) issuersList); |
| // the PendingIntent is used to get calling package name |
| intent.putExtra(EXTRA_SENDER, PendingIntent.getActivity(activity, 0, new Intent(), |
| PendingIntent.FLAG_IMMUTABLE)); |
| activity.startActivity(intent); |
| } |
| |
| /** |
| * Check whether the caller is the credential management app {@code CredentialManagementApp}. |
| * The credential management app has the ability to manage the user's KeyChain credentials |
| * on unmanaged devices. |
| * |
| * <p> {@link KeyChain#createManageCredentialsIntent} should be used by an app to request to |
| * become the credential management app. The user must approve this request before the app can |
| * manage the user's credentials. There can only be one credential management on the device. |
| * |
| * @return {@code true} if the caller is the credential management app. |
| */ |
| @WorkerThread |
| public static boolean isCredentialManagementApp(@NonNull Context context) { |
| boolean isCredentialManagementApp = false; |
| try (KeyChainConnection keyChainConnection = KeyChain.bind(context)) { |
| isCredentialManagementApp = keyChainConnection.getService() |
| .isCredentialManagementApp(context.getPackageName()); |
| } catch (RemoteException e) { |
| e.rethrowAsRuntimeException(); |
| } catch (InterruptedException e) { |
| throw new RuntimeException("Interrupted while checking whether the caller is the " |
| + "credential management app.", e); |
| } catch (SecurityException e) { |
| isCredentialManagementApp = false; |
| } |
| return isCredentialManagementApp; |
| } |
| |
| /** |
| * Called by the credential management app to get the authentication policy |
| * {@link AppUriAuthenticationPolicy}. |
| * |
| * @return the credential management app's authentication policy. |
| * @throws SecurityException if the caller is not the credential management app. |
| */ |
| @WorkerThread |
| @NonNull |
| public static AppUriAuthenticationPolicy getCredentialManagementAppPolicy( |
| @NonNull Context context) throws SecurityException { |
| AppUriAuthenticationPolicy policy = null; |
| try (KeyChainConnection keyChainConnection = KeyChain.bind(context)) { |
| policy = keyChainConnection.getService().getCredentialManagementAppPolicy(); |
| } catch (RemoteException e) { |
| e.rethrowAsRuntimeException(); |
| } catch (InterruptedException e) { |
| throw new RuntimeException( |
| "Interrupted while getting credential management app policy.", e); |
| } |
| return policy; |
| } |
| |
| /** |
| * Set a credential management app. The credential management app has the ability to manage |
| * the user's KeyChain credentials on unmanaged devices. |
| * |
| * <p>There can only be one credential management on the device. If another app requests to |
| * become the credential management app, then the existing credential management app will |
| * no longer be able to manage credentials. |
| * |
| * @param packageName The package name of the credential management app |
| * @param authenticationPolicy The authentication policy of the credential management app. This |
| * policy determines which alias for a private key and certificate |
| * pair should be used for authentication. |
| * @return {@code true} if the credential management app was successfully added. |
| * @hide |
| */ |
| @TestApi |
| @WorkerThread |
| @RequiresPermission(Manifest.permission.MANAGE_CREDENTIAL_MANAGEMENT_APP) |
| public static boolean setCredentialManagementApp(@NonNull Context context, |
| @NonNull String packageName, @NonNull AppUriAuthenticationPolicy authenticationPolicy) { |
| try (KeyChainConnection keyChainConnection = KeyChain.bind(context)) { |
| keyChainConnection.getService() |
| .setCredentialManagementApp(packageName, authenticationPolicy); |
| return true; |
| } catch (RemoteException | InterruptedException e) { |
| Log.w(LOG, "Set credential management app failed", e); |
| Thread.currentThread().interrupt(); |
| return false; |
| } |
| } |
| |
| /** |
| * Called by the credential management app {@code CredentialManagementApp} to unregister as |
| * the credential management app and stop managing the user's credentials. |
| * |
| * <p> All credentials previously installed by the credential management app will be removed |
| * from the user's device. |
| * |
| * <p> An app holding {@code MANAGE_CREDENTIAL_MANAGEMENT_APP} permission can also call this |
| * method to remove the current credential management app, even if it's not the current |
| * credential management app itself. |
| * |
| * @return {@code true} if the credential management app was successfully removed. |
| */ |
| @WorkerThread |
| @RequiresPermission(value = Manifest.permission.MANAGE_CREDENTIAL_MANAGEMENT_APP, |
| conditional = true) |
| public static boolean removeCredentialManagementApp(@NonNull Context context) { |
| try (KeyChainConnection keyChainConnection = KeyChain.bind(context)) { |
| keyChainConnection.getService().removeCredentialManagementApp(); |
| return true; |
| } catch (RemoteException | InterruptedException e) { |
| Log.w(LOG, "Remove credential management app failed", e); |
| Thread.currentThread().interrupt(); |
| return false; |
| } |
| } |
| |
| private static class AliasResponse extends IKeyChainAliasCallback.Stub { |
| private final KeyChainAliasCallback keyChainAliasResponse; |
| private AliasResponse(KeyChainAliasCallback keyChainAliasResponse) { |
| this.keyChainAliasResponse = keyChainAliasResponse; |
| } |
| @Override public void alias(String alias) { |
| keyChainAliasResponse.alias(alias); |
| } |
| } |
| |
| /** |
| * Returns the {@code PrivateKey} for the requested alias, or null if the alias does not exist |
| * or the caller has no permission to access it (see note on exceptions below). |
| * |
| * <p> This method may block while waiting for a connection to another process, and must never |
| * be called from the main thread. |
| * <p> As {@link Activity} and {@link Service} contexts are short-lived and can be destroyed |
| * at any time from the main thread, it is safer to rely on a long-lived context such as one |
| * returned from {@link Context#getApplicationContext()}. |
| * |
| * <p> If the caller provides a valid alias to which it was not granted access, then the |
| * caller must invoke {@link #choosePrivateKeyAlias} again to get another valid alias |
| * or a grant to access the same alias. |
| * <p>On Android versions prior to Q, when a key associated with the specified alias is |
| * unavailable, the method will throw a {@code KeyChainException} rather than return null. |
| * If the exception's cause (as obtained by calling {@code KeyChainException.getCause()}) |
| * is a throwable of type {@code IllegalStateException} then the caller lacks a grant |
| * to access the key and certificates associated with this alias. |
| * |
| * @param alias The alias of the desired private key, typically returned via |
| * {@link KeyChainAliasCallback#alias}. |
| * @throws KeyChainException if the alias was valid but there was some problem accessing it. |
| * @throws IllegalStateException if called from the main thread. |
| */ |
| @Nullable @WorkerThread |
| public static PrivateKey getPrivateKey(@NonNull Context context, @NonNull String alias) |
| throws KeyChainException, InterruptedException { |
| KeyPair keyPair = getKeyPair(context, alias); |
| if (keyPair != null) { |
| return keyPair.getPrivate(); |
| } |
| |
| return null; |
| } |
| |
| /** |
| * This prefix is used to disambiguate grant aliase strings from normal key alias strings. |
| * Technically, a key alias string can use the same prefix. However, a collision does not |
| * lead to privilege escalation, because grants are access controlled in the Keystore daemon. |
| * @hide |
| */ |
| public static final String GRANT_ALIAS_PREFIX = "ks2_keychain_grant_id:"; |
| |
| private static KeyDescriptor getGrantDescriptor(String keyid) { |
| KeyDescriptor result = new KeyDescriptor(); |
| result.domain = Domain.GRANT; |
| result.blob = null; |
| result.alias = null; |
| try { |
| result.nspace = Long.parseUnsignedLong( |
| keyid.substring(GRANT_ALIAS_PREFIX.length()), 16 /* radix */); |
| } catch (NumberFormatException e) { |
| return null; |
| } |
| return result; |
| } |
| |
| /** @hide */ |
| public static String getGrantString(KeyDescriptor key) { |
| return String.format(GRANT_ALIAS_PREFIX + "%016X", key.nspace); |
| } |
| |
| /** @hide */ |
| @Nullable @WorkerThread |
| public static KeyPair getKeyPair(@NonNull Context context, @NonNull String alias) |
| throws KeyChainException, InterruptedException { |
| if (alias == null) { |
| throw new NullPointerException("alias == null"); |
| } |
| if (context == null) { |
| throw new NullPointerException("context == null"); |
| } |
| |
| final String keyId; |
| try (KeyChainConnection keyChainConnection = bind(context.getApplicationContext())) { |
| keyId = keyChainConnection.getService().requestPrivateKey(alias); |
| } catch (RemoteException e) { |
| throw new KeyChainException(e); |
| } catch (RuntimeException e) { |
| // only certain RuntimeExceptions can be propagated across the IKeyChainService call |
| throw new KeyChainException(e); |
| } |
| |
| if (keyId == null) { |
| return null; |
| } |
| |
| if (AndroidKeyStoreProvider.isKeystore2Enabled()) { |
| try { |
| return android.security.keystore2.AndroidKeyStoreProvider |
| .loadAndroidKeyStoreKeyPairFromKeystore( |
| KeyStore2.getInstance(), |
| getGrantDescriptor(keyId)); |
| } catch (UnrecoverableKeyException | KeyPermanentlyInvalidatedException e) { |
| throw new KeyChainException(e); |
| } |
| } else { |
| try { |
| return AndroidKeyStoreProvider.loadAndroidKeyStoreKeyPairFromKeystore( |
| KeyStore.getInstance(), keyId, KeyStore.UID_SELF); |
| } catch (RuntimeException | UnrecoverableKeyException |
| | KeyPermanentlyInvalidatedException e) { |
| throw new KeyChainException(e); |
| } |
| } |
| } |
| |
| /** |
| * Returns the {@code X509Certificate} chain for the requested alias, or null if the alias |
| * does not exist or the caller has no permission to access it (see note on exceptions |
| * in {@link #getPrivateKey}). |
| * |
| * <p> |
| * <strong>Note:</strong> If a certificate chain was explicitly specified when the alias was |
| * installed, this method will return that chain. If only the client certificate was specified |
| * at the installation time, this method will try to build a certificate chain using all |
| * available trust anchors (preinstalled and user-added). |
| * |
| * <p> This method may block while waiting for a connection to another process, and must never |
| * be called from the main thread. |
| * <p> As {@link Activity} and {@link Service} contexts are short-lived and can be destroyed |
| * at any time from the main thread, it is safer to rely on a long-lived context such as one |
| * returned from {@link Context#getApplicationContext()}. |
| * <p> In case the caller specifies an alias for which it lacks a grant, it must call |
| * {@link #choosePrivateKeyAlias} again. See {@link #getPrivateKey} for more details on |
| * coping with this scenario. |
| * |
| * @param alias The alias of the desired certificate chain, typically |
| * returned via {@link KeyChainAliasCallback#alias}. |
| * @throws KeyChainException if the alias was valid but there was some problem accessing it. |
| * @throws IllegalStateException if called from the main thread. |
| */ |
| @Nullable @WorkerThread |
| public static X509Certificate[] getCertificateChain(@NonNull Context context, |
| @NonNull String alias) throws KeyChainException, InterruptedException { |
| if (alias == null) { |
| throw new NullPointerException("alias == null"); |
| } |
| |
| final byte[] certificateBytes; |
| final byte[] certChainBytes; |
| try (KeyChainConnection keyChainConnection = bind(context.getApplicationContext())) { |
| IKeyChainService keyChainService = keyChainConnection.getService(); |
| certificateBytes = keyChainService.getCertificate(alias); |
| if (certificateBytes == null) { |
| return null; |
| } |
| certChainBytes = keyChainService.getCaCertificates(alias); |
| } catch (RemoteException e) { |
| throw new KeyChainException(e); |
| } catch (RuntimeException e) { |
| // only certain RuntimeExceptions can be propagated across the IKeyChainService call |
| throw new KeyChainException(e); |
| } |
| |
| try { |
| X509Certificate leafCert = toCertificate(certificateBytes); |
| // If the keypair is installed with a certificate chain by either |
| // DevicePolicyManager.installKeyPair or CertInstaller, return that chain. |
| if (certChainBytes != null && certChainBytes.length != 0) { |
| Collection<X509Certificate> chain = toCertificates(certChainBytes); |
| ArrayList<X509Certificate> fullChain = new ArrayList<>(chain.size() + 1); |
| fullChain.add(leafCert); |
| fullChain.addAll(chain); |
| return fullChain.toArray(new X509Certificate[fullChain.size()]); |
| } else { |
| // If there isn't a certificate chain, either due to a pre-existing keypair |
| // installed before N, or no chain is explicitly installed under the new logic, |
| // fall back to old behavior of constructing the chain from trusted credentials. |
| // |
| // This logic exists to maintain old behaviour for already installed keypair, at |
| // the cost of potentially returning extra certificate chain for new clients who |
| // explicitly installed only the client certificate without a chain. The latter |
| // case is actually no different from pre-N behaviour of getCertificateChain(), |
| // in that sense this change introduces no regression. Besides the returned chain |
| // is still valid so the consumer of the chain should have no problem verifying it. |
| TrustedCertificateStore store = new TrustedCertificateStore(); |
| List<X509Certificate> chain = store.getCertificateChain(leafCert); |
| return chain.toArray(new X509Certificate[chain.size()]); |
| } |
| } catch (CertificateException | RuntimeException e) { |
| throw new KeyChainException(e); |
| } |
| } |
| |
| /** |
| * Returns {@code true} if the current device's {@code KeyChain} supports a |
| * specific {@code PrivateKey} type indicated by {@code algorithm} (e.g., |
| * "RSA"). |
| */ |
| public static boolean isKeyAlgorithmSupported( |
| @NonNull @KeyProperties.KeyAlgorithmEnum String algorithm) { |
| final String algUpper = algorithm.toUpperCase(Locale.US); |
| return KeyProperties.KEY_ALGORITHM_EC.equals(algUpper) |
| || KeyProperties.KEY_ALGORITHM_RSA.equals(algUpper); |
| } |
| |
| /** |
| * Returns {@code true} if the current device's {@code KeyChain} binds any |
| * {@code PrivateKey} of the given {@code algorithm} to the device once |
| * imported or generated. This can be used to tell if there is special |
| * hardware support that can be used to bind keys to the device in a way |
| * that makes it non-exportable. |
| * |
| * @deprecated Whether the key is bound to the secure hardware is known only |
| * once the key has been imported. To find out, use: |
| * <pre>{@code |
| * PrivateKey key = ...; // private key from KeyChain |
| * |
| * KeyFactory keyFactory = |
| * KeyFactory.getInstance(key.getAlgorithm(), "AndroidKeyStore"); |
| * KeyInfo keyInfo = keyFactory.getKeySpec(key, KeyInfo.class); |
| * if (keyInfo.isInsideSecureHardware()) { |
| * // The key is bound to the secure hardware of this Android |
| * }}</pre> |
| */ |
| @Deprecated |
| public static boolean isBoundKeyAlgorithm( |
| @NonNull @KeyProperties.KeyAlgorithmEnum String algorithm) { |
| // All supported algorithms are hardware backed. Individual keys may not be. |
| return true; |
| } |
| |
| /** @hide */ |
| @NonNull |
| public static X509Certificate toCertificate(@NonNull 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); |
| } |
| } |
| |
| /** @hide */ |
| @NonNull |
| public static Collection<X509Certificate> toCertificates(@NonNull byte[] bytes) { |
| if (bytes == null) { |
| throw new IllegalArgumentException("bytes == null"); |
| } |
| try { |
| CertificateFactory certFactory = CertificateFactory.getInstance("X.509"); |
| return (Collection<X509Certificate>) certFactory.generateCertificates( |
| new ByteArrayInputStream(bytes)); |
| } catch (CertificateException e) { |
| throw new AssertionError(e); |
| } |
| } |
| |
| /** |
| * @hide for reuse by CertInstaller and Settings. |
| * @see KeyChain#bind |
| */ |
| public static class KeyChainConnection implements Closeable { |
| private final Context mContext; |
| private final ServiceConnection mServiceConnection; |
| private final IKeyChainService mService; |
| protected KeyChainConnection(Context context, |
| ServiceConnection serviceConnection, |
| IKeyChainService service) { |
| this.mContext = context; |
| this.mServiceConnection = serviceConnection; |
| this.mService = service; |
| } |
| @Override public void close() { |
| mContext.unbindService(mServiceConnection); |
| } |
| |
| /** returns the service binder. */ |
| public IKeyChainService getService() { |
| return mService; |
| } |
| } |
| |
| /** |
| * Bind to KeyChainService in the current user. |
| * Caller should call unbindService on the result when finished. |
| * |
| *@throws InterruptedException if interrupted during binding. |
| *@throws AssertionError if unable to bind to KeyChainService. |
| * @hide for reuse by CertInstaller and Settings. |
| */ |
| @WorkerThread |
| public static KeyChainConnection bind(@NonNull Context context) throws InterruptedException { |
| return bindAsUser(context, Process.myUserHandle()); |
| } |
| |
| /** |
| * Bind to KeyChainService in the target user. |
| * Caller should call unbindService on the result when finished. |
| * |
| * @throws InterruptedException if interrupted during binding. |
| * @throws AssertionError if unable to bind to KeyChainService. |
| * @hide |
| */ |
| @WorkerThread |
| public static KeyChainConnection bindAsUser(@NonNull Context context, UserHandle user) |
| throws InterruptedException { |
| return bindAsUser(context, null, user); |
| } |
| |
| /** |
| * Returns a persistable grant string that allows WiFi stack to access the key using Keystore |
| * SSL engine. |
| * |
| * @return grant string or null if key is not granted or doesn't exist. |
| * |
| * The key should be granted to Process.WIFI_UID. |
| * @hide |
| */ |
| @SystemApi |
| @Nullable |
| @WorkerThread |
| public static String getWifiKeyGrantAsUser( |
| @NonNull Context context, @NonNull UserHandle user, @NonNull String alias) { |
| try (KeyChainConnection keyChainConnection = |
| bindAsUser(context.getApplicationContext(), user)) { |
| return keyChainConnection.getService().getWifiKeyGrantAsUser(alias); |
| } catch (RemoteException | RuntimeException e) { |
| Log.i(LOG, "Couldn't get grant for wifi", e); |
| return null; |
| } catch (InterruptedException e) { |
| Thread.currentThread().interrupt(); |
| Log.i(LOG, "Interrupted while getting grant for wifi", e); |
| return null; |
| } |
| } |
| |
| /** |
| * Returns whether the key is granted to WiFi stack. |
| * @hide |
| */ |
| @SystemApi |
| @WorkerThread |
| public static boolean hasWifiKeyGrantAsUser( |
| @NonNull Context context, @NonNull UserHandle user, @NonNull String alias) { |
| try (KeyChainConnection keyChainConnection = |
| bindAsUser(context.getApplicationContext(), user)) { |
| return keyChainConnection.getService().hasGrant(Process.WIFI_UID, alias); |
| } catch (RemoteException | RuntimeException e) { |
| Log.i(LOG, "Couldn't query grant for wifi", e); |
| return false; |
| } catch (InterruptedException e) { |
| Thread.currentThread().interrupt(); |
| Log.i(LOG, "Interrupted while querying grant for wifi", e); |
| return false; |
| } |
| } |
| |
| /** |
| * Bind to KeyChainService in the target user. |
| * Caller should call unbindService on the result when finished. |
| * |
| * @throws InterruptedException if interrupted during binding. |
| * @throws AssertionError if unable to bind to KeyChainService. |
| * @hide |
| */ |
| public static KeyChainConnection bindAsUser(@NonNull Context context, @Nullable Handler handler, |
| UserHandle user) throws InterruptedException { |
| |
| if (context == null) { |
| throw new NullPointerException("context == null"); |
| } |
| if (handler == null) { |
| ensureNotOnMainThread(context); |
| } |
| if (!UserManager.get(context).isUserUnlocked(user)) { |
| throw new IllegalStateException("User must be unlocked"); |
| } |
| |
| final CountDownLatch countDownLatch = new CountDownLatch(1); |
| final AtomicReference<IKeyChainService> keyChainService = new AtomicReference<>(); |
| ServiceConnection keyChainServiceConnection = new ServiceConnection() { |
| volatile boolean mConnectedAtLeastOnce = false; |
| @Override public void onServiceConnected(ComponentName name, IBinder service) { |
| if (!mConnectedAtLeastOnce) { |
| mConnectedAtLeastOnce = true; |
| keyChainService.set( |
| IKeyChainService.Stub.asInterface(Binder.allowBlocking(service))); |
| countDownLatch.countDown(); |
| } |
| } |
| @Override public void onBindingDied(ComponentName name) { |
| if (!mConnectedAtLeastOnce) { |
| mConnectedAtLeastOnce = true; |
| countDownLatch.countDown(); |
| } |
| } |
| @Override public void onServiceDisconnected(ComponentName name) {} |
| }; |
| Intent intent = new Intent(IKeyChainService.class.getName()); |
| ComponentName comp = intent.resolveSystemService(context.getPackageManager(), 0); |
| if (comp == null) { |
| throw new AssertionError("could not resolve KeyChainService"); |
| } |
| intent.setComponent(comp); |
| final boolean bindSucceed; |
| if (handler != null) { |
| bindSucceed = context.bindServiceAsUser( |
| intent, keyChainServiceConnection, Context.BIND_AUTO_CREATE, handler, user); |
| } else { |
| bindSucceed = context.bindServiceAsUser( |
| intent, keyChainServiceConnection, Context.BIND_AUTO_CREATE, user); |
| } |
| if (!bindSucceed) { |
| throw new AssertionError("could not bind to KeyChainService"); |
| } |
| countDownLatch.await(); |
| IKeyChainService service = keyChainService.get(); |
| if (service != null) { |
| return new KeyChainConnection(context, keyChainServiceConnection, service); |
| } else { |
| context.unbindService(keyChainServiceConnection); |
| throw new AssertionError("KeyChainService died while binding"); |
| } |
| } |
| |
| private static void ensureNotOnMainThread(@NonNull 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"); |
| } |
| } |
| } |