Merge "[MAC rand] Fix unit test slowness"

4 files changed, 143 insertions, 104 deletions

diff --git a/service/java/com/android/server/wifi/MacAddressUtil.java b/service/java/com/android/server/wifi/MacAddressUtil.java
new file mode 100644
index 000000000..effa931a5
--- /dev/null
+++ b/service/java/com/android/server/wifi/MacAddressUtil.java
@@ -0,0 +1,133 @@
+/*
+ * 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.server.wifi;
+
+import android.net.MacAddress;
+import android.net.wifi.WifiConfiguration;
+import android.security.keystore.AndroidKeyStoreProvider;
+import android.security.keystore.KeyGenParameterSpec;
+import android.security.keystore.KeyProperties;
+import android.util.Log;
+
+import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
+import java.security.InvalidAlgorithmParameterException;
+import java.security.InvalidKeyException;
+import java.security.Key;
+import java.security.KeyStore;
+import java.security.KeyStoreException;
+import java.security.NoSuchAlgorithmException;
+import java.security.NoSuchProviderException;
+import java.security.ProviderException;
+import java.security.UnrecoverableKeyException;
+import java.util.Arrays;
+
+import javax.crypto.KeyGenerator;
+import javax.crypto.Mac;
+import javax.crypto.SecretKey;
+
+/**
+ * Contains helper methods to support MAC randomization.
+ */
+public class MacAddressUtil {
+    private static final String TAG = "MacAddressUtil";
+    private static final String MAC_RANDOMIZATION_ALIAS = "MacRandSecret";
+    private static final long MAC_ADDRESS_VALID_LONG_MASK = (1L << 48) - 1;
+    private static final long MAC_ADDRESS_LOCALLY_ASSIGNED_MASK = 1L << 41;
+    private static final long MAC_ADDRESS_MULTICAST_MASK = 1L << 40;
+
+    /**
+     * Computes the persistent randomized MAC of the given configuration using the given
+     * hash function.
+     * @param config the WifiConfiguration to compute MAC address for
+     * @param hashFunction the hash function that will perform the MAC address computation.
+     * @return The persistent randomized MAC address or null if inputs are invalid.
+     */
+    public MacAddress calculatePersistentMacForConfiguration(WifiConfiguration config,
+            Mac hashFunction) {
+        if (config == null || hashFunction == null) {
+            return null;
+        }
+        byte[] hashedBytes = hashFunction.doFinal(
+                config.getSsidAndSecurityTypeString().getBytes(StandardCharsets.UTF_8));
+        ByteBuffer bf = ByteBuffer.wrap(hashedBytes);
+        long longFromSsid = bf.getLong();
+        /**
+         * Masks the generated long so that it represents a valid randomized MAC address.
+         * Specifically, this sets the locally assigned bit to 1, multicast bit to 0
+         */
+        longFromSsid &= MAC_ADDRESS_VALID_LONG_MASK;
+        longFromSsid |= MAC_ADDRESS_LOCALLY_ASSIGNED_MASK;
+        longFromSsid &= ~MAC_ADDRESS_MULTICAST_MASK;
+        bf.clear();
+        bf.putLong(0, longFromSsid);
+
+        // MacAddress.fromBytes requires input of length 6, which is obtained from the
+        // last 6 bytes from the generated long.
+        MacAddress macAddress = MacAddress.fromBytes(Arrays.copyOfRange(bf.array(), 2, 8));
+        return macAddress;
+    }
+
+    /**
+     * Retrieves a Hash function that could be used to calculate the persistent randomized MAC
+     * for a WifiConfiguration.
+     * @param uid the UID of the KeyStore to get the secret of the hash function from.
+     */
+    public Mac obtainMacRandHashFunction(int uid) {
+        try {
+            KeyStore keyStore = AndroidKeyStoreProvider.getKeyStoreForUid(uid);
+            // tries to retrieve the secret, and generate a new one if it's unavailable.
+            Key key = keyStore.getKey(MAC_RANDOMIZATION_ALIAS, null);
+            if (key == null) {
+                key = generateAndPersistNewMacRandomizationSecret(uid);
+            }
+            if (key == null) {
+                Log.e(TAG, "Failed to generate secret for " + MAC_RANDOMIZATION_ALIAS);
+                return null;
+            }
+            Mac result = Mac.getInstance("HmacSHA256");
+            result.init(key);
+            return result;
+        } catch (KeyStoreException | NoSuchAlgorithmException | InvalidKeyException
+                | UnrecoverableKeyException | NoSuchProviderException e) {
+            Log.e(TAG, "Failure in obtainMacRandHashFunction", e);
+            return null;
+        }
+    }
+
+    /**
+     * Generates and returns a secret key to use for Mac randomization.
+     * Will also persist the generated secret inside KeyStore, accessible in the
+     * future with KeyGenerator#getKey.
+     */
+    private SecretKey generateAndPersistNewMacRandomizationSecret(int uid) {
+        try {
+            KeyGenerator keyGenerator = KeyGenerator.getInstance(
+                    KeyProperties.KEY_ALGORITHM_HMAC_SHA256, "AndroidKeyStore");
+            keyGenerator.init(
+                    new KeyGenParameterSpec.Builder(MAC_RANDOMIZATION_ALIAS,
+                            KeyProperties.PURPOSE_SIGN)
+                            .setUid(uid)
+                            .build());
+            return keyGenerator.generateKey();
+        } catch (NoSuchAlgorithmException | InvalidAlgorithmParameterException
+                | NoSuchProviderException | ProviderException e) {
+            Log.e(TAG, "Failure in generateMacRandomizationSecret", e);
+            return null;
+        }
+    }
+}
diff --git a/service/java/com/android/server/wifi/WifiConfigManager.java b/service/java/com/android/server/wifi/WifiConfigManager.java
index b4d5ef3bb..b0d679256 100644
--- a/service/java/com/android/server/wifi/WifiConfigManager.java
+++ b/service/java/com/android/server/wifi/WifiConfigManager.java
@@ -281,6 +281,7 @@ public class WifiConfigManager {
     private final WifiPermissionsUtil mWifiPermissionsUtil;
     private final WifiPermissionsWrapper mWifiPermissionsWrapper;
     private final WifiInjector mWifiInjector;
+    private final MacAddressUtil mMacAddressUtil;
     private boolean mConnectedMacRandomzationSupported;
     private final Mac mMac;
 
@@ -472,7 +473,8 @@ public class WifiConfigManager {
         } catch (PackageManager.NameNotFoundException e) {
             Log.e(TAG, "Unable to resolve SystemUI's UID.");
         }
-        mMac = WifiConfigurationUtil.obtainMacRandHashFunction(Process.WIFI_UID);
+        mMacAddressUtil = mWifiInjector.getMacAddressUtil();
+        mMac = mMacAddressUtil.obtainMacRandHashFunction(Process.WIFI_UID);
         if (mMac == null) {
             Log.wtf(TAG, "Failed to obtain secret for MAC randomization."
                     + " All randomized MAC addresses are lost!");
@@ -571,7 +573,7 @@ public class WifiConfigManager {
                 mRandomizedMacAddressMapping.remove(config.getSsidAndSecurityTypeString());
             }
         }
-        return WifiConfigurationUtil.calculatePersistentMacForConfiguration(config, mMac);
+        return mMacAddressUtil.calculatePersistentMacForConfiguration(config, mMac);
     }
 
     /**
diff --git a/service/java/com/android/server/wifi/WifiConfigurationUtil.java b/service/java/com/android/server/wifi/WifiConfigurationUtil.java
index f79cc9230..facc999bd 100644
--- a/service/java/com/android/server/wifi/WifiConfigurationUtil.java
+++ b/service/java/com/android/server/wifi/WifiConfigurationUtil.java
@@ -26,9 +26,6 @@ import android.net.wifi.WifiEnterpriseConfig;
 import android.net.wifi.WifiNetworkSpecifier;
 import android.net.wifi.WifiScanner;
 import android.os.PatternMatcher;
-import android.security.keystore.AndroidKeyStoreProvider;
-import android.security.keystore.KeyGenParameterSpec;
-import android.security.keystore.KeyProperties;
 import android.text.TextUtils;
 import android.util.Log;
 import android.util.Pair;
@@ -37,27 +34,13 @@ import com.android.internal.annotations.VisibleForTesting;
 import com.android.server.wifi.util.NativeUtil;
 import com.android.server.wifi.util.TelephonyUtil;
 
-import java.nio.ByteBuffer;
 import java.nio.charset.StandardCharsets;
-import java.security.InvalidAlgorithmParameterException;
-import java.security.InvalidKeyException;
-import java.security.Key;
-import java.security.KeyStore;
-import java.security.KeyStoreException;
-import java.security.NoSuchAlgorithmException;
-import java.security.NoSuchProviderException;
-import java.security.ProviderException;
-import java.security.UnrecoverableKeyException;
 import java.security.cert.X509Certificate;
 import java.util.Arrays;
 import java.util.BitSet;
 import java.util.Comparator;
 import java.util.Objects;
 
-import javax.crypto.KeyGenerator;
-import javax.crypto.Mac;
-import javax.crypto.SecretKey;
-
 /**
  * WifiConfiguration utility for any {@link android.net.wifi.WifiConfiguration} related operations.
  * Currently contains:
@@ -88,10 +71,6 @@ public class WifiConfigurationUtil {
             new Pair(MacAddress.BROADCAST_ADDRESS, MacAddress.BROADCAST_ADDRESS);
     private static final Pair<MacAddress, MacAddress> MATCH_ALL_BSSID_PATTERN =
             new Pair(ALL_ZEROS_MAC_ADDRESS, ALL_ZEROS_MAC_ADDRESS);
-    private static final String MAC_RANDOMIZATION_ALIAS = "MacRandSecret";
-    private static final long MAC_ADDRESS_VALID_LONG_MASK = (1L << 48) - 1;
-    private static final long MAC_ADDRESS_LOCALLY_ASSIGNED_MASK = 1L << 41;
-    private static final long MAC_ADDRESS_MULTICAST_MASK = 1L << 40;
 
     /**
      * Checks if the provided |wepKeys| array contains any non-null value;
@@ -216,87 +195,6 @@ public class WifiConfigurationUtil {
     }
 
     /**
-     * Computes the persistent randomized MAC of the given configuration using the given
-     * hash function.
-     * @param config the WifiConfiguration to compute MAC address for
-     * @param hashFunction the hash function that will perform the MAC address computation.
-     * @return The persistent randomized MAC address or null if inputs are invalid.
-     */
-    public static MacAddress calculatePersistentMacForConfiguration(WifiConfiguration config,
-            Mac hashFunction) {
-        if (config == null || hashFunction == null) {
-            return null;
-        }
-        byte[] hashedBytes = hashFunction.doFinal(
-                config.getSsidAndSecurityTypeString().getBytes(StandardCharsets.UTF_8));
-        ByteBuffer bf = ByteBuffer.wrap(hashedBytes);
-        long longFromSsid = bf.getLong();
-        /**
-         * Masks the generated long so that it represents a valid randomized MAC address.
-         * Specifically, this sets the locally assigned bit to 1, multicast bit to 0
-         */
-        longFromSsid &= MAC_ADDRESS_VALID_LONG_MASK;
-        longFromSsid |= MAC_ADDRESS_LOCALLY_ASSIGNED_MASK;
-        longFromSsid &= ~MAC_ADDRESS_MULTICAST_MASK;
-        bf.clear();
-        bf.putLong(0, longFromSsid);
-
-        // MacAddress.fromBytes requires input of length 6, which is obtained from the
-        // last 6 bytes from the generated long.
-        MacAddress macAddress = MacAddress.fromBytes(Arrays.copyOfRange(bf.array(), 2, 8));
-        return macAddress;
-    }
-
-    /**
-     * Retrieves a Hash function that could be used to calculate the persistent randomized MAC
-     * for a WifiConfiguration.
-     * @param uid the UID of the KeyStore to get the secret of the hash function from.
-     */
-    public static Mac obtainMacRandHashFunction(int uid) {
-        try {
-            KeyStore keyStore = AndroidKeyStoreProvider.getKeyStoreForUid(uid);
-            // tries to retrieve the secret, and generate a new one if it's unavailable.
-            Key key = keyStore.getKey(MAC_RANDOMIZATION_ALIAS, null);
-            if (key == null) {
-                key = generateAndPersistNewMacRandomizationSecret(uid);
-            }
-            if (key == null) {
-                Log.e(TAG, "Failed to generate secret for " + MAC_RANDOMIZATION_ALIAS);
-                return null;
-            }
-            Mac result = Mac.getInstance("HmacSHA256");
-            result.init(key);
-            return result;
-        } catch (KeyStoreException | NoSuchAlgorithmException | InvalidKeyException
-                | UnrecoverableKeyException | NoSuchProviderException e) {
-            Log.e(TAG, "Failure in obtainMacRandHashFunction", e);
-            return null;
-        }
-    }
-
-    /**
-     * Generates and returns a secret key to use for Mac randomization.
-     * Will also persist the generated secret inside KeyStore, accessible in the
-     * future with KeyGenerator#getKey.
-     */
-    private static SecretKey generateAndPersistNewMacRandomizationSecret(int uid) {
-        try {
-            KeyGenerator keyGenerator = KeyGenerator.getInstance(
-                    KeyProperties.KEY_ALGORITHM_HMAC_SHA256, "AndroidKeyStore");
-            keyGenerator.init(
-                    new KeyGenParameterSpec.Builder(MAC_RANDOMIZATION_ALIAS,
-                            KeyProperties.PURPOSE_SIGN)
-                            .setUid(uid)
-                            .build());
-            return keyGenerator.generateKey();
-        } catch (NoSuchAlgorithmException | InvalidAlgorithmParameterException
-                | NoSuchProviderException | ProviderException e) {
-            Log.e(TAG, "Failure in generateMacRandomizationSecret", e);
-            return null;
-        }
-    }
-
-    /**
      * Compare existing and new WifiEnterpriseConfig objects after a network update and return if
      * credential parameters have changed or not.
      *
diff --git a/service/java/com/android/server/wifi/WifiInjector.java b/service/java/com/android/server/wifi/WifiInjector.java
index 219373501..1e2dac8d7 100644
--- a/service/java/com/android/server/wifi/WifiInjector.java
+++ b/service/java/com/android/server/wifi/WifiInjector.java
@@ -152,6 +152,7 @@ public class WifiInjector {
     private IpMemoryStore mIpMemoryStore;
     private final WifiThreadRunner mWifiThreadRunner;
     private BssidBlocklistMonitor mBssidBlocklistMonitor;
+    private final MacAddressUtil mMacAddressUtil;
 
     public WifiInjector(Context context) {
         if (context == null) {
@@ -167,6 +168,7 @@ public class WifiInjector {
         sWifiInjector = this;
 
         mFrameworkFacade = new FrameworkFacade();
+        mMacAddressUtil = new MacAddressUtil();
         mContext = context;
         mBatteryStats = context.getSystemService(BatteryStatsManager.class);
         mWifiScoreCard = new WifiScoreCard(mClock,
@@ -666,6 +668,10 @@ public class WifiInjector {
         return mRttHandlerThread;
     }
 
+    public MacAddressUtil getMacAddressUtil() {
+        return mMacAddressUtil;
+    }
+
     /**
      * Returns a single instance of HalDeviceManager for injection.
      */