Building IMSI encryption support.

Added additional error checks while returning the key.
Create config parameter:
1. IMSI_KEY_AVAILABILITY_INT.
BUG: 35606429
Test: manual

Change-Id: Iaa5fed3b51719679051626081d82b85a04128896

diff --git a/telephony/java/android/telephony/CarrierConfigManager.java b/telephony/java/android/telephony/CarrierConfigManager.java
index 81353df..735f09b 100644 (file)
--- a/telephony/java/android/telephony/CarrierConfigManager.java
+++ b/telephony/java/android/telephony/CarrierConfigManager.java
@@ -1173,8 +1173,6 @@ public class CarrierConfigManager {
     /** @hide */
     public static final int CDMA_ROAMING_MODE_AFFILIATED = 1;
     /** @hide */
-    public static final int IMSI_ENCRYPTION_DAYS_TIME_DISABLED = -1;
-    /** @hide */
     public static final int CDMA_ROAMING_MODE_ANY = 2;
     /**
      * Boolean indicating if support is provided for directly dialing FDN number from FDN list.
@@ -1533,14 +1531,15 @@ public class CarrierConfigManager {
     public static final String IMSI_KEY_DOWNLOAD_URL_STRING = "imsi_key_download_url_string";
 
     /**
-     * Time in days, after which the key will expire, and a new key will need to be downloaded.
-     * default value is {@link IMSI_ENCRYPTION_DAYS_TIME_DISABLED}, and indicates that IMSI
-     * encryption is not enabled by default for a carrier. Value of 0 indicates that the key
-     * does not expire.
+     * Identifies if the key is available for WLAN or EPDG or both. The value is a bitmask.
+     * 0 indicates that neither EPDG or WLAN is enabled.
+     * 1 indicates that key type {@link TelephonyManager#KEY_TYPE_EPDG} is enabled.
+     * 2 indicates that key type {@link TelephonyManager#KEY_TYPE_WLAN} is enabled.
+     * 3 indicates that both are enabled.
      * @hide
      */
-    public static final String IMSI_KEY_EXPIRATION_DAYS_TIME_INT =
-            "imsi_key_expiration_days_time_int";
+    public static final String IMSI_KEY_AVAILABILITY_INT = "imsi_key_availability_int";
+
 
     /**
      * Key identifying if the CDMA Caller ID presentation and suppression MMI codes
@@ -1814,7 +1813,7 @@ public class CarrierConfigManager {
         sDefaults.putInt(KEY_LTE_EARFCNS_RSRP_BOOST_INT, 0);
         sDefaults.putStringArray(KEY_BOOSTED_LTE_EARFCNS_STRING_ARRAY, null);
         sDefaults.putBoolean(KEY_DISABLE_VOICE_BARRING_NOTIFICATION_BOOL, false);
-        sDefaults.putInt(IMSI_KEY_EXPIRATION_DAYS_TIME_INT, IMSI_ENCRYPTION_DAYS_TIME_DISABLED);
+        sDefaults.putInt(IMSI_KEY_AVAILABILITY_INT, 0);
         sDefaults.putString(IMSI_KEY_DOWNLOAD_URL_STRING, null);
         sDefaults.putBoolean(KEY_CONVERT_CDMA_CALLER_ID_MMI_CODES_WHILE_ROAMING_ON_3GPP_BOOL,
                 false);

diff --git a/telephony/java/android/telephony/TelephonyManager.java b/telephony/java/android/telephony/TelephonyManager.java
index 6a9d00e..5f4283f 100644 (file)
--- a/telephony/java/android/telephony/TelephonyManager.java
+++ b/telephony/java/android/telephony/TelephonyManager.java
@@ -137,7 +137,7 @@ public class TelephonyManager {
 
 
     /** @hide */
-    static public final int KEY_TYPE_EPDDG = 1;
+    static public final int KEY_TYPE_EPDG = 1;
 
     /** @hide */
     static public final int KEY_TYPE_WLAN = 2;
@@ -2373,31 +2373,73 @@ public class TelephonyManager {
      * Requires Permission:
      *   {@link android.Manifest.permission#READ_PHONE_STATE READ_PHONE_STATE}
      * @param keyType whether the key is being used for wlan or epdg. Valid key types are
-     *        {@link TelephonyManager#KEY_TYPE_EPDDG} or
+     *        {@link TelephonyManager#KEY_TYPE_EPDG} or
      *        {@link TelephonyManager#KEY_TYPE_WLAN}.
      * @return ImsiEncryptionInfo Carrier specific information that will be used to encrypt the
      *         IMSI and IMPI. This includes the public key and the key identifier. This information
-     *         will be stored in the device keystore.
+     *         will be stored in the device keystore. The system will return a null when no key was
+     *         found, and the carrier does not require a key. The system will throw the following
+     *         exceptions:
+     *         1. IllegalArgumentException when an invalid key is sent.
+     *         2. RuntimeException if the key is required but not found; and also if there was an
+     *         internal exception.
      * @hide
      */
     public ImsiEncryptionInfo getCarrierInfoForImsiEncryption(int keyType) {
         try {
             IPhoneSubInfo info = getSubscriberInfo();
-            if (info == null) return null;
+            if (info == null) {
+                throw new RuntimeException("IMSI error: Subscriber Info is null");
+            }
             int subId = getSubId(SubscriptionManager.getDefaultDataSubscriptionId());
-            if (keyType != KEY_TYPE_EPDDG && keyType != KEY_TYPE_WLAN) {
-                throw new IllegalArgumentException("Invalid key type");
+            if (keyType != KEY_TYPE_EPDG && keyType != KEY_TYPE_WLAN) {
+                throw new IllegalArgumentException("IMSI error: Invalid key type");
+            }
+            ImsiEncryptionInfo imsiEncryptionInfo = info.getCarrierInfoForImsiEncryption(
+                    subId, keyType, mContext.getOpPackageName());
+            if (imsiEncryptionInfo  == null
+                    && isImsiEncryptionRequired(subId, keyType)) {
+                Rlog.e(TAG, "IMSI error: key is required but not found");
+                throw new RuntimeException("IMSI error: key is required but not found");
             }
-            return info.getCarrierInfoForImsiEncryption(subId, keyType,
-                    mContext.getOpPackageName());
+            return imsiEncryptionInfo;
         } catch (RemoteException ex) {
-            Rlog.e(TAG, "getCarrierInfoForImsiEncryption RemoteException", ex);
-            return null;
+            Rlog.e(TAG, "getCarrierInfoForImsiEncryption RemoteException" + ex);
+            throw new RuntimeException("IMSI error: Remote Exception");
         } catch (NullPointerException ex) {
             // This could happen before phone restarts due to crashing
-            Rlog.e(TAG, "getCarrierInfoForImsiEncryption NullPointerException", ex);
-            return null;
+            Rlog.e(TAG, "getCarrierInfoForImsiEncryption NullPointerException" + ex);
+            throw new RuntimeException("IMSI error: Null Pointer exception");
+        }
+    }
+
+   /**
+     * @param keyAvailability bitmask that defines the availabilty of keys for a type.
+     * @param keyType the key type which is being checked. (WLAN, EPDG)
+     * @return true if the digit at position keyType is 1, else false.
+     * @hide
+     */
+    private static boolean isKeyEnabled(int keyAvailability, int keyType) {
+        int returnValue = (keyAvailability >> (keyType - 1)) & 1;
+        return (returnValue == 1) ? true : false;
+    }
+
+    /**
+     * If Carrier requires Imsi to be encrypted.
+     * @hide
+     */
+    private boolean isImsiEncryptionRequired(int subId, int keyType) {
+        CarrierConfigManager configManager =
+                (CarrierConfigManager) mContext.getSystemService(Context.CARRIER_CONFIG_SERVICE);
+        if (configManager == null) {
+            return false;
+        }
+        PersistableBundle pb = configManager.getConfigForSubId(subId);
+        if (pb == null) {
+            return false;
         }
+        int keyAvailability = pb.getInt(CarrierConfigManager.IMSI_KEY_AVAILABILITY_INT);
+        return isKeyEnabled(keyAvailability, keyType);
     }
 
     /**