| /* |
| * 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.connectivity; |
| |
| import static android.net.ConnectivityManager.NetworkCallback; |
| import static android.net.ipsec.ike.SaProposal.DH_GROUP_2048_BIT_MODP; |
| import static android.net.ipsec.ike.SaProposal.ENCRYPTION_ALGORITHM_AES_CBC; |
| import static android.net.ipsec.ike.SaProposal.ENCRYPTION_ALGORITHM_AES_GCM_12; |
| import static android.net.ipsec.ike.SaProposal.ENCRYPTION_ALGORITHM_AES_GCM_16; |
| import static android.net.ipsec.ike.SaProposal.ENCRYPTION_ALGORITHM_AES_GCM_8; |
| import static android.net.ipsec.ike.SaProposal.INTEGRITY_ALGORITHM_AES_XCBC_96; |
| import static android.net.ipsec.ike.SaProposal.INTEGRITY_ALGORITHM_HMAC_SHA2_256_128; |
| import static android.net.ipsec.ike.SaProposal.INTEGRITY_ALGORITHM_HMAC_SHA2_384_192; |
| import static android.net.ipsec.ike.SaProposal.INTEGRITY_ALGORITHM_HMAC_SHA2_512_256; |
| import static android.net.ipsec.ike.SaProposal.KEY_LEN_AES_128; |
| import static android.net.ipsec.ike.SaProposal.KEY_LEN_AES_192; |
| import static android.net.ipsec.ike.SaProposal.KEY_LEN_AES_256; |
| import static android.net.ipsec.ike.SaProposal.PSEUDORANDOM_FUNCTION_AES128_XCBC; |
| import static android.net.ipsec.ike.SaProposal.PSEUDORANDOM_FUNCTION_HMAC_SHA1; |
| |
| import android.annotation.NonNull; |
| import android.content.Context; |
| import android.net.Ikev2VpnProfile; |
| import android.net.InetAddresses; |
| import android.net.IpPrefix; |
| import android.net.IpSecAlgorithm; |
| import android.net.IpSecTransform; |
| import android.net.Network; |
| import android.net.RouteInfo; |
| import android.net.eap.EapSessionConfig; |
| import android.net.ipsec.ike.ChildSaProposal; |
| import android.net.ipsec.ike.ChildSessionCallback; |
| import android.net.ipsec.ike.ChildSessionConfiguration; |
| import android.net.ipsec.ike.ChildSessionParams; |
| import android.net.ipsec.ike.IkeFqdnIdentification; |
| import android.net.ipsec.ike.IkeIdentification; |
| import android.net.ipsec.ike.IkeIpv4AddrIdentification; |
| import android.net.ipsec.ike.IkeIpv6AddrIdentification; |
| import android.net.ipsec.ike.IkeKeyIdIdentification; |
| import android.net.ipsec.ike.IkeRfc822AddrIdentification; |
| import android.net.ipsec.ike.IkeSaProposal; |
| import android.net.ipsec.ike.IkeSessionCallback; |
| import android.net.ipsec.ike.IkeSessionConfiguration; |
| import android.net.ipsec.ike.IkeSessionParams; |
| import android.net.ipsec.ike.IkeTrafficSelector; |
| import android.net.ipsec.ike.TunnelModeChildSessionParams; |
| import android.net.ipsec.ike.exceptions.IkeException; |
| import android.net.ipsec.ike.exceptions.IkeProtocolException; |
| import android.net.util.IpRange; |
| import android.system.OsConstants; |
| import android.util.Log; |
| |
| import com.android.internal.net.VpnProfile; |
| import com.android.internal.util.HexDump; |
| |
| import java.net.Inet4Address; |
| import java.net.Inet6Address; |
| import java.net.InetAddress; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.Collection; |
| import java.util.HashSet; |
| import java.util.List; |
| |
| /** |
| * Utility class to build and convert IKEv2/IPsec parameters. |
| * |
| * @hide |
| */ |
| public class VpnIkev2Utils { |
| private static final String TAG = VpnIkev2Utils.class.getSimpleName(); |
| |
| // TODO: Use IKE library exposed constants when @SystemApi is updated. |
| /** IANA-defined 3072 group for use in IKEv2 */ |
| private static final int DH_GROUP_3072_BIT_MODP = 15; |
| /** IANA-defined 4096 group for use in IKEv2 */ |
| private static final int DH_GROUP_4096_BIT_MODP = 16; |
| |
| static IkeSessionParams buildIkeSessionParams( |
| @NonNull Context context, @NonNull Ikev2VpnProfile profile, @NonNull Network network) { |
| final IkeIdentification localId = parseIkeIdentification(profile.getUserIdentity()); |
| final IkeIdentification remoteId = parseIkeIdentification(profile.getServerAddr()); |
| |
| final IkeSessionParams.Builder ikeOptionsBuilder = |
| new IkeSessionParams.Builder(context) |
| .setServerHostname(profile.getServerAddr()) |
| .setNetwork(network) |
| .setLocalIdentification(localId) |
| .setRemoteIdentification(remoteId); |
| setIkeAuth(profile, ikeOptionsBuilder); |
| |
| for (final IkeSaProposal ikeProposal : getIkeSaProposals()) { |
| ikeOptionsBuilder.addSaProposal(ikeProposal); |
| } |
| |
| return ikeOptionsBuilder.build(); |
| } |
| |
| static ChildSessionParams buildChildSessionParams(List<String> allowedAlgorithms) { |
| final TunnelModeChildSessionParams.Builder childOptionsBuilder = |
| new TunnelModeChildSessionParams.Builder(); |
| |
| for (final ChildSaProposal childProposal : getChildSaProposals(allowedAlgorithms)) { |
| childOptionsBuilder.addSaProposal(childProposal); |
| } |
| |
| childOptionsBuilder.addInternalAddressRequest(OsConstants.AF_INET); |
| childOptionsBuilder.addInternalAddressRequest(OsConstants.AF_INET6); |
| childOptionsBuilder.addInternalDnsServerRequest(OsConstants.AF_INET); |
| childOptionsBuilder.addInternalDnsServerRequest(OsConstants.AF_INET6); |
| |
| return childOptionsBuilder.build(); |
| } |
| |
| private static void setIkeAuth( |
| @NonNull Ikev2VpnProfile profile, @NonNull IkeSessionParams.Builder builder) { |
| switch (profile.getType()) { |
| case VpnProfile.TYPE_IKEV2_IPSEC_USER_PASS: |
| final EapSessionConfig eapConfig = |
| new EapSessionConfig.Builder() |
| .setEapMsChapV2Config(profile.getUsername(), profile.getPassword()) |
| .build(); |
| builder.setAuthEap(profile.getServerRootCaCert(), eapConfig); |
| break; |
| case VpnProfile.TYPE_IKEV2_IPSEC_PSK: |
| builder.setAuthPsk(profile.getPresharedKey()); |
| break; |
| case VpnProfile.TYPE_IKEV2_IPSEC_RSA: |
| builder.setAuthDigitalSignature( |
| profile.getServerRootCaCert(), |
| profile.getUserCert(), |
| profile.getRsaPrivateKey()); |
| break; |
| default: |
| throw new IllegalArgumentException("Unknown auth method set"); |
| } |
| } |
| |
| private static List<IkeSaProposal> getIkeSaProposals() { |
| // TODO: Add ability to filter this when IKEv2 API is made Public API |
| final List<IkeSaProposal> proposals = new ArrayList<>(); |
| |
| // Encryption Algorithms: Currently only AES_CBC is supported. |
| final IkeSaProposal.Builder normalModeBuilder = new IkeSaProposal.Builder(); |
| |
| // Currently only AES_CBC is supported. |
| normalModeBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_CBC, KEY_LEN_AES_256); |
| normalModeBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_CBC, KEY_LEN_AES_192); |
| normalModeBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_CBC, KEY_LEN_AES_128); |
| |
| // Authentication/Integrity Algorithms |
| normalModeBuilder.addIntegrityAlgorithm(INTEGRITY_ALGORITHM_HMAC_SHA2_512_256); |
| normalModeBuilder.addIntegrityAlgorithm(INTEGRITY_ALGORITHM_HMAC_SHA2_384_192); |
| normalModeBuilder.addIntegrityAlgorithm(INTEGRITY_ALGORITHM_HMAC_SHA2_256_128); |
| normalModeBuilder.addIntegrityAlgorithm(INTEGRITY_ALGORITHM_AES_XCBC_96); |
| |
| // Add AEAD options |
| final IkeSaProposal.Builder aeadBuilder = new IkeSaProposal.Builder(); |
| aeadBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_GCM_16, KEY_LEN_AES_256); |
| aeadBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_GCM_12, KEY_LEN_AES_256); |
| aeadBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_GCM_8, KEY_LEN_AES_256); |
| aeadBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_GCM_16, KEY_LEN_AES_192); |
| aeadBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_GCM_12, KEY_LEN_AES_192); |
| aeadBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_GCM_8, KEY_LEN_AES_192); |
| aeadBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_GCM_16, KEY_LEN_AES_128); |
| aeadBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_GCM_12, KEY_LEN_AES_128); |
| aeadBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_GCM_8, KEY_LEN_AES_128); |
| |
| // Add dh, prf for both builders |
| for (final IkeSaProposal.Builder builder : Arrays.asList(normalModeBuilder, aeadBuilder)) { |
| builder.addDhGroup(DH_GROUP_4096_BIT_MODP); |
| builder.addDhGroup(DH_GROUP_3072_BIT_MODP); |
| builder.addDhGroup(DH_GROUP_2048_BIT_MODP); |
| builder.addPseudorandomFunction(PSEUDORANDOM_FUNCTION_AES128_XCBC); |
| builder.addPseudorandomFunction(PSEUDORANDOM_FUNCTION_HMAC_SHA1); |
| } |
| |
| proposals.add(normalModeBuilder.build()); |
| proposals.add(aeadBuilder.build()); |
| return proposals; |
| } |
| |
| /** Builds a child SA proposal based on the allowed IPsec algorithms */ |
| private static List<ChildSaProposal> getChildSaProposals(List<String> allowedAlgorithms) { |
| final List<ChildSaProposal> proposals = new ArrayList<>(); |
| |
| // Add non-AEAD options |
| if (Ikev2VpnProfile.hasNormalModeAlgorithms(allowedAlgorithms)) { |
| final ChildSaProposal.Builder normalModeBuilder = new ChildSaProposal.Builder(); |
| |
| // Encryption Algorithms: |
| // AES-CBC is currently the only supported encryption algorithm. |
| normalModeBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_CBC, KEY_LEN_AES_256); |
| normalModeBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_CBC, KEY_LEN_AES_192); |
| normalModeBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_CBC, KEY_LEN_AES_128); |
| |
| // Authentication/Integrity Algorithms: |
| // Guaranteed by Ikev2VpnProfile constructor to contain at least one of these. |
| if (allowedAlgorithms.contains(IpSecAlgorithm.AUTH_HMAC_SHA512)) { |
| normalModeBuilder.addIntegrityAlgorithm(INTEGRITY_ALGORITHM_HMAC_SHA2_512_256); |
| } |
| if (allowedAlgorithms.contains(IpSecAlgorithm.AUTH_HMAC_SHA384)) { |
| normalModeBuilder.addIntegrityAlgorithm(INTEGRITY_ALGORITHM_HMAC_SHA2_384_192); |
| } |
| if (allowedAlgorithms.contains(IpSecAlgorithm.AUTH_HMAC_SHA256)) { |
| normalModeBuilder.addIntegrityAlgorithm(INTEGRITY_ALGORITHM_HMAC_SHA2_256_128); |
| } |
| |
| ChildSaProposal proposal = normalModeBuilder.build(); |
| if (proposal.getIntegrityAlgorithms().isEmpty()) { |
| // Should be impossible; Verified in Ikev2VpnProfile. |
| Log.wtf(TAG, "Missing integrity algorithm when buildling Child SA proposal"); |
| } else { |
| proposals.add(normalModeBuilder.build()); |
| } |
| } |
| |
| // Add AEAD options |
| if (Ikev2VpnProfile.hasAeadAlgorithms(allowedAlgorithms)) { |
| final ChildSaProposal.Builder aeadBuilder = new ChildSaProposal.Builder(); |
| |
| // AES-GCM is currently the only supported AEAD algorithm |
| aeadBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_GCM_16, KEY_LEN_AES_256); |
| aeadBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_GCM_12, KEY_LEN_AES_256); |
| aeadBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_GCM_8, KEY_LEN_AES_256); |
| aeadBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_GCM_16, KEY_LEN_AES_192); |
| aeadBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_GCM_12, KEY_LEN_AES_192); |
| aeadBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_GCM_8, KEY_LEN_AES_192); |
| aeadBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_GCM_16, KEY_LEN_AES_128); |
| aeadBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_GCM_12, KEY_LEN_AES_128); |
| aeadBuilder.addEncryptionAlgorithm(ENCRYPTION_ALGORITHM_AES_GCM_8, KEY_LEN_AES_128); |
| |
| proposals.add(aeadBuilder.build()); |
| } |
| |
| return proposals; |
| } |
| |
| static class IkeSessionCallbackImpl implements IkeSessionCallback { |
| private final String mTag; |
| private final Vpn.IkeV2VpnRunnerCallback mCallback; |
| private final Network mNetwork; |
| |
| IkeSessionCallbackImpl(String tag, Vpn.IkeV2VpnRunnerCallback callback, Network network) { |
| mTag = tag; |
| mCallback = callback; |
| mNetwork = network; |
| } |
| |
| @Override |
| public void onOpened(@NonNull IkeSessionConfiguration ikeSessionConfig) { |
| Log.d(mTag, "IkeOpened for network " + mNetwork); |
| // Nothing to do here. |
| } |
| |
| @Override |
| public void onClosed() { |
| Log.d(mTag, "IkeClosed for network " + mNetwork); |
| mCallback.onSessionLost(mNetwork, null); // Server requested session closure. Retry? |
| } |
| |
| @Override |
| public void onClosedExceptionally(@NonNull IkeException exception) { |
| Log.d(mTag, "IkeClosedExceptionally for network " + mNetwork, exception); |
| mCallback.onSessionLost(mNetwork, exception); |
| } |
| |
| @Override |
| public void onError(@NonNull IkeProtocolException exception) { |
| Log.d(mTag, "IkeError for network " + mNetwork, exception); |
| // Non-fatal, log and continue. |
| } |
| } |
| |
| static class ChildSessionCallbackImpl implements ChildSessionCallback { |
| private final String mTag; |
| private final Vpn.IkeV2VpnRunnerCallback mCallback; |
| private final Network mNetwork; |
| |
| ChildSessionCallbackImpl(String tag, Vpn.IkeV2VpnRunnerCallback callback, Network network) { |
| mTag = tag; |
| mCallback = callback; |
| mNetwork = network; |
| } |
| |
| @Override |
| public void onOpened(@NonNull ChildSessionConfiguration childConfig) { |
| Log.d(mTag, "ChildOpened for network " + mNetwork); |
| mCallback.onChildOpened(mNetwork, childConfig); |
| } |
| |
| @Override |
| public void onClosed() { |
| Log.d(mTag, "ChildClosed for network " + mNetwork); |
| mCallback.onSessionLost(mNetwork, null); |
| } |
| |
| @Override |
| public void onClosedExceptionally(@NonNull IkeException exception) { |
| Log.d(mTag, "ChildClosedExceptionally for network " + mNetwork, exception); |
| mCallback.onSessionLost(mNetwork, exception); |
| } |
| |
| @Override |
| public void onIpSecTransformCreated(@NonNull IpSecTransform transform, int direction) { |
| Log.d(mTag, "ChildTransformCreated; Direction: " + direction + "; network " + mNetwork); |
| mCallback.onChildTransformCreated(mNetwork, transform, direction); |
| } |
| |
| @Override |
| public void onIpSecTransformDeleted(@NonNull IpSecTransform transform, int direction) { |
| // Nothing to be done; no references to the IpSecTransform are held by the |
| // Ikev2VpnRunner (or this callback class), and this transform will be closed by the |
| // IKE library. |
| Log.d(mTag, |
| "ChildTransformDeleted; Direction: " + direction + "; for network " + mNetwork); |
| } |
| } |
| |
| static class Ikev2VpnNetworkCallback extends NetworkCallback { |
| private final String mTag; |
| private final Vpn.IkeV2VpnRunnerCallback mCallback; |
| |
| Ikev2VpnNetworkCallback(String tag, Vpn.IkeV2VpnRunnerCallback callback) { |
| mTag = tag; |
| mCallback = callback; |
| } |
| |
| @Override |
| public void onAvailable(@NonNull Network network) { |
| Log.d(mTag, "Starting IKEv2/IPsec session on new network: " + network); |
| mCallback.onDefaultNetworkChanged(network); |
| } |
| |
| @Override |
| public void onLost(@NonNull Network network) { |
| Log.d(mTag, "Tearing down; lost network: " + network); |
| mCallback.onSessionLost(network, null); |
| } |
| } |
| |
| /** |
| * Identity parsing logic using similar logic to open source implementations of IKEv2 |
| * |
| * <p>This method does NOT support using type-prefixes (eg 'fqdn:' or 'keyid'), or ASN.1 encoded |
| * identities. |
| */ |
| private static IkeIdentification parseIkeIdentification(@NonNull String identityStr) { |
| // TODO: Add identity formatting to public API javadocs. |
| if (identityStr.contains("@")) { |
| if (identityStr.startsWith("@#")) { |
| // KEY_ID |
| final String hexStr = identityStr.substring(2); |
| return new IkeKeyIdIdentification(HexDump.hexStringToByteArray(hexStr)); |
| } else if (identityStr.startsWith("@@")) { |
| // RFC822 (USER_FQDN) |
| return new IkeRfc822AddrIdentification(identityStr.substring(2)); |
| } else if (identityStr.startsWith("@")) { |
| // FQDN |
| return new IkeFqdnIdentification(identityStr.substring(1)); |
| } else { |
| // RFC822 (USER_FQDN) |
| return new IkeRfc822AddrIdentification(identityStr); |
| } |
| } else if (InetAddresses.isNumericAddress(identityStr)) { |
| final InetAddress addr = InetAddresses.parseNumericAddress(identityStr); |
| if (addr instanceof Inet4Address) { |
| // IPv4 |
| return new IkeIpv4AddrIdentification((Inet4Address) addr); |
| } else if (addr instanceof Inet6Address) { |
| // IPv6 |
| return new IkeIpv6AddrIdentification((Inet6Address) addr); |
| } else { |
| throw new IllegalArgumentException("IP version not supported"); |
| } |
| } else { |
| if (identityStr.contains(":")) { |
| // KEY_ID |
| return new IkeKeyIdIdentification(identityStr.getBytes()); |
| } else { |
| // FQDN |
| return new IkeFqdnIdentification(identityStr); |
| } |
| } |
| } |
| |
| static Collection<RouteInfo> getRoutesFromTrafficSelectors( |
| List<IkeTrafficSelector> trafficSelectors) { |
| final HashSet<RouteInfo> routes = new HashSet<>(); |
| |
| for (final IkeTrafficSelector selector : trafficSelectors) { |
| for (final IpPrefix prefix : |
| new IpRange(selector.startingAddress, selector.endingAddress).asIpPrefixes()) { |
| routes.add(new RouteInfo(prefix, null)); |
| } |
| } |
| |
| return routes; |
| } |
| } |
