1 /* 2 * Copyright (C) 2015 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package libcore.net; 18 19 /** 20 * Network security policy for this process/application. 21 * 22 * <p>Network stacks/components are expected to honor this policy. Components which can use the 23 * Android framework API should be accessing this policy via the framework's 24 * {@code android.security.NetworkSecurityPolicy} instead of via this class. 25 * 26 * <p>The policy currently consists of a single flag: whether cleartext network traffic is 27 * permitted. See {@link #isCleartextTrafficPermitted()}. 28 */ 29 public abstract class NetworkSecurityPolicy { 30 31 private static volatile NetworkSecurityPolicy instance = new DefaultNetworkSecurityPolicy(); 32 getInstance()33 public static NetworkSecurityPolicy getInstance() { 34 return instance; 35 } 36 setInstance(NetworkSecurityPolicy policy)37 public static void setInstance(NetworkSecurityPolicy policy) { 38 if (policy == null) { 39 throw new NullPointerException("policy == null"); 40 } 41 instance = policy; 42 } 43 44 /** 45 * Returns {@code true} if cleartext network traffic (e.g. HTTP, FTP, XMPP, IMAP, SMTP -- 46 * without TLS or STARTTLS) is permitted for all network communications of this process. 47 * 48 * <p>{@link #isCleartextTrafficPermitted(String)} should be used to determine if cleartext 49 * traffic is permitted for a specific host. 50 * 51 * <p>When cleartext network traffic is not permitted, the platform's components (e.g. HTTP 52 * stacks, {@code WebView}, {@code MediaPlayer}) will refuse this process's requests to use 53 * cleartext traffic. Third-party libraries are encouraged to do the same. 54 * 55 * <p>This flag is honored on a best effort basis because it's impossible to prevent all 56 * cleartext traffic from an application given the level of access provided to applications on 57 * Android. For example, there's no expectation that {@link java.net.Socket} API will honor this 58 * flag. Luckily, most network traffic from apps is handled by higher-level network stacks which 59 * can be made to honor this flag. Platform-provided network stacks (e.g. HTTP and FTP) honor 60 * this flag from day one, and well-established third-party network stacks will eventually 61 * honor it. 62 */ isCleartextTrafficPermitted()63 public abstract boolean isCleartextTrafficPermitted(); 64 65 /** 66 * Returns {@code true} if cleartext network traffic (e.g. HTTP, FTP, XMPP, IMAP, SMTP -- 67 * without TLS or STARTTLS) is permitted for communicating with {@code hostname} for this 68 * process. 69 * 70 * <p>See {@link #isCleartextTrafficPermitted} for more details. 71 */ isCleartextTrafficPermitted(String hostname)72 public abstract boolean isCleartextTrafficPermitted(String hostname); 73 74 public static final class DefaultNetworkSecurityPolicy extends NetworkSecurityPolicy { 75 @Override isCleartextTrafficPermitted()76 public boolean isCleartextTrafficPermitted() { 77 return true; 78 } 79 80 @Override isCleartextTrafficPermitted(String hostname)81 public boolean isCleartextTrafficPermitted(String hostname) { 82 return isCleartextTrafficPermitted(); 83 } 84 } 85 } 86