Merge "DSU to support GSI key revocation list"

3 files changed, 195 insertions, 2 deletions

diff --git a/packages/DynamicSystemInstallationService/src/com/android/dynsystem/DynamicSystemInstallationService.java b/packages/DynamicSystemInstallationService/src/com/android/dynsystem/DynamicSystemInstallationService.java
index 9ccb837cf613..9bae223a0a3e 100644
--- a/packages/DynamicSystemInstallationService/src/com/android/dynsystem/DynamicSystemInstallationService.java
+++ b/packages/DynamicSystemInstallationService/src/com/android/dynsystem/DynamicSystemInstallationService.java
@@ -46,6 +46,7 @@ import android.app.PendingIntent;
 import android.app.Service;
 import android.content.Context;
 import android.content.Intent;
+import android.net.http.HttpResponseCache;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.IBinder;
@@ -60,6 +61,8 @@ import android.text.TextUtils;
 import android.util.Log;
 import android.widget.Toast;
 
+import java.io.File;
+import java.io.IOException;
 import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 
@@ -146,10 +149,26 @@ public class DynamicSystemInstallationService extends Service
         prepareNotification();
 
         mDynSystem = (DynamicSystemManager) getSystemService(Context.DYNAMIC_SYSTEM_SERVICE);
+
+        // Install an HttpResponseCache in the application cache directory so we can cache
+        // gsi key revocation list. The http(s) protocol handler uses this cache transparently.
+        // The cache size is chosen heuristically. Since we don't have too much traffic right now,
+        // a moderate size of 1MiB should be enough.
+        try {
+            File httpCacheDir = new File(getCacheDir(), "httpCache");
+            long httpCacheSize = 1 * 1024 * 1024; // 1 MiB
+            HttpResponseCache.install(httpCacheDir, httpCacheSize);
+        } catch (IOException e) {
+            Log.d(TAG, "HttpResponseCache.install() failed: " + e);
+        }
     }
 
     @Override
     public void onDestroy() {
+        HttpResponseCache cache = HttpResponseCache.getInstalled();
+        if (cache != null) {
+            cache.flush();
+        }
         // Cancel the persistent notification.
         mNM.cancel(NOTIFICATION_ID);
     }
diff --git a/packages/DynamicSystemInstallationService/src/com/android/dynsystem/InstallationAsyncTask.java b/packages/DynamicSystemInstallationService/src/com/android/dynsystem/InstallationAsyncTask.java
index 9aea0e713179..438c435ef0e4 100644
--- a/packages/DynamicSystemInstallationService/src/com/android/dynsystem/InstallationAsyncTask.java
+++ b/packages/DynamicSystemInstallationService/src/com/android/dynsystem/InstallationAsyncTask.java
@@ -25,6 +25,8 @@ import android.os.image.DynamicSystemManager;
 import android.util.Log;
 import android.webkit.URLUtil;
 
+import org.json.JSONException;
+
 import java.io.BufferedInputStream;
 import java.io.File;
 import java.io.IOException;
@@ -100,7 +102,9 @@ class InstallationAsyncTask extends AsyncTask<String, InstallationAsyncTask.Prog
     private final Context mContext;
     private final DynamicSystemManager mDynSystem;
     private final ProgressListener mListener;
+    private final boolean mIsNetworkUrl;
     private DynamicSystemManager.Session mInstallationSession;
+    private KeyRevocationList mKeyRevocationList;
 
     private boolean mIsZip;
     private boolean mIsCompleted;
@@ -123,6 +127,7 @@ class InstallationAsyncTask extends AsyncTask<String, InstallationAsyncTask.Prog
         mContext = context;
         mDynSystem = dynSystem;
         mListener = listener;
+        mIsNetworkUrl = URLUtil.isNetworkUrl(mUrl);
     }
 
     @Override
@@ -152,9 +157,11 @@ class InstallationAsyncTask extends AsyncTask<String, InstallationAsyncTask.Prog
                 return null;
             }
 
+            // TODO(yochiang): do post-install public key check (revocation list / boot-ramdisk)
+
             mDynSystem.finishInstallation();
         } catch (Exception e) {
-            e.printStackTrace();
+            Log.e(TAG, e.toString(), e);
             mDynSystem.remove();
             return e;
         } finally {
@@ -220,7 +227,7 @@ class InstallationAsyncTask extends AsyncTask<String, InstallationAsyncTask.Prog
                 String.format(Locale.US, "Unsupported file format: %s", mUrl));
         }
 
-        if (URLUtil.isNetworkUrl(mUrl)) {
+        if (mIsNetworkUrl) {
             mStream = new URL(mUrl).openStream();
         } else if (URLUtil.isFileUrl(mUrl)) {
             if (mIsZip) {
@@ -234,6 +241,25 @@ class InstallationAsyncTask extends AsyncTask<String, InstallationAsyncTask.Prog
             throw new UnsupportedUrlException(
                     String.format(Locale.US, "Unsupported URL: %s", mUrl));
         }
+
+        // TODO(yochiang): Bypass this check if device is unlocked
+        try {
+            String listUrl = mContext.getString(R.string.key_revocation_list_url);
+            mKeyRevocationList = KeyRevocationList.fromUrl(new URL(listUrl));
+        } catch (IOException | JSONException e) {
+            Log.d(TAG, "Failed to fetch Dynamic System Key Revocation List");
+            mKeyRevocationList = new KeyRevocationList();
+            keyRevocationThrowOrWarning(e);
+        }
+    }
+
+    private void keyRevocationThrowOrWarning(Exception e) throws Exception {
+        if (mIsNetworkUrl) {
+            throw e;
+        } else {
+            // If DSU is being installed from a local file URI, then be permissive
+            Log.w(TAG, e.toString());
+        }
     }
 
     private void installUserdata() throws Exception {
diff --git a/packages/DynamicSystemInstallationService/src/com/android/dynsystem/KeyRevocationList.java b/packages/DynamicSystemInstallationService/src/com/android/dynsystem/KeyRevocationList.java
new file mode 100644
index 000000000000..522bc547325b
--- /dev/null
+++ b/packages/DynamicSystemInstallationService/src/com/android/dynsystem/KeyRevocationList.java
@@ -0,0 +1,148 @@
+/*
+ * Copyright (C) 2019 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.dynsystem;
+
+import android.text.TextUtils;
+import android.util.Log;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URL;
+import java.net.URLConnection;
+import java.util.HashMap;
+
+class KeyRevocationList {
+
+    private static final String TAG = "KeyRevocationList";
+
+    private static final String JSON_ENTRIES = "entries";
+    private static final String JSON_PUBLIC_KEY = "public_key";
+    private static final String JSON_STATUS = "status";
+    private static final String JSON_REASON = "reason";
+
+    private static final String STATUS_REVOKED = "REVOKED";
+
+    @VisibleForTesting
+    HashMap<String, RevocationStatus> mEntries;
+
+    static class RevocationStatus {
+        final String mStatus;
+        final String mReason;
+
+        RevocationStatus(String status, String reason) {
+            mStatus = status;
+            mReason = reason;
+        }
+    }
+
+    KeyRevocationList() {
+        mEntries = new HashMap<String, RevocationStatus>();
+    }
+
+    /**
+     * Returns the revocation status of a public key.
+     *
+     * @return a RevocationStatus for |publicKey|, null if |publicKey| doesn't exist.
+     */
+    RevocationStatus getRevocationStatusForKey(String publicKey) {
+        return mEntries.get(publicKey);
+    }
+
+    /** Test if a public key is revoked or not. */
+    boolean isRevoked(String publicKey) {
+        RevocationStatus entry = getRevocationStatusForKey(publicKey);
+        return entry != null && TextUtils.equals(entry.mStatus, STATUS_REVOKED);
+    }
+
+    @VisibleForTesting
+    void addEntry(String publicKey, String status, String reason) {
+        mEntries.put(publicKey, new RevocationStatus(status, reason));
+    }
+
+    /**
+     * Creates a KeyRevocationList from a JSON String.
+     *
+     * @param jsonString the revocation list, for example:
+     *     <pre>{@code
+     *      {
+     *        "entries": [
+     *          {
+     *            "public_key": "00fa2c6637c399afa893fe83d85f3569998707d5",
+     *            "status": "REVOKED",
+     *            "reason": "Revocation Reason"
+     *          }
+     *        ]
+     *      }
+     *     }</pre>
+     *
+     * @throws JSONException if |jsonString| is malformed.
+     */
+    static KeyRevocationList fromJsonString(String jsonString) throws JSONException {
+        JSONObject jsonObject = new JSONObject(jsonString);
+        KeyRevocationList list = new KeyRevocationList();
+        Log.d(TAG, "Begin of revocation list");
+        if (jsonObject.has(JSON_ENTRIES)) {
+            JSONArray entries = jsonObject.getJSONArray(JSON_ENTRIES);
+            for (int i = 0; i < entries.length(); ++i) {
+                JSONObject entry = entries.getJSONObject(i);
+                String publicKey = entry.getString(JSON_PUBLIC_KEY);
+                String status = entry.getString(JSON_STATUS);
+                String reason = entry.has(JSON_REASON) ? entry.getString(JSON_REASON) : "";
+                list.addEntry(publicKey, status, reason);
+                Log.d(TAG, "Revocation entry: " + entry.toString());
+            }
+        }
+        Log.d(TAG, "End of revocation list");
+        return list;
+    }
+
+    /**
+     * Creates a KeyRevocationList from a URL.
+     *
+     * @throws IOException if |url| is inaccessible.
+     * @throws JSONException if fetched content is malformed.
+     */
+    static KeyRevocationList fromUrl(URL url) throws IOException, JSONException {
+        Log.d(TAG, "Fetch from URL: " + url.toString());
+        // Force "conditional GET"
+        // Force validate the cached result with server each time, and use the cached result
+        // only if it is validated by server, else fetch new data from server.
+        // Ref: https://developer.android.com/reference/android/net/http/HttpResponseCache#force-a-network-response
+        URLConnection connection = url.openConnection();
+        connection.setUseCaches(true);
+        connection.addRequestProperty("Cache-Control", "max-age=0");
+        try (InputStream stream = connection.getInputStream()) {
+            return fromJsonString(readFully(stream));
+        }
+    }
+
+    private static String readFully(InputStream in) throws IOException {
+        int n;
+        byte[] buffer = new byte[4096];
+        StringBuilder builder = new StringBuilder();
+        while ((n = in.read(buffer, 0, 4096)) > -1) {
+            builder.append(new String(buffer, 0, n));
+        }
+        return builder.toString();
+    }
+}