src/java/com/android/internal/telephony/CarrierInfoManager.java - platform/frameworks/opt/telephony - Git at Google

 /*
  * Copyright (C) 2017 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.internal.telephony;

 import android.content.ContentResolver;
 import android.content.ContentValues;
 import android.content.Context;
 import android.content.Intent;
 import android.database.Cursor;
 import android.database.sqlite.SQLiteConstraintException;
 import android.os.UserHandle;
 import android.provider.Telephony;
 import android.telephony.ImsiEncryptionInfo;
 import android.telephony.TelephonyManager;
 import android.text.TextUtils;
 import android.util.Log;

 import java.util.Date;

 /**
  * This class provides methods to retreive information from the CarrierKeyProvider.
  */
 public class CarrierInfoManager {
     private static final String LOG_TAG = "CarrierInfoManager";
     private static final String KEY_TYPE = "KEY_TYPE";

     /*
     * Rate limit (in milliseconds) the number of times the Carrier keys can be reset.
     * Do it at most once every 12 hours.
     */
     private static final int RESET_CARRIER_KEY_RATE_LIMIT = 12 * 60 * 60 * 1000;

     // Last time the resetCarrierKeysForImsiEncryption API was called successfully.
     private long mLastAccessResetCarrierKey = 0;

     /**
      * Returns Carrier specific information that will be used to encrypt the IMSI and IMPI.
      * @param keyType whether the key is being used for WLAN or ePDG.
      * @param mContext
      * @return ImsiEncryptionInfo which contains the information, including the public key, to be
      *         used for encryption.
      */
     public static ImsiEncryptionInfo getCarrierInfoForImsiEncryption(int keyType,
                                                                      Context mContext) {
         String mcc = "";
         String mnc = "";
         final TelephonyManager telephonyManager =
                 (TelephonyManager) mContext.getSystemService(Context.TELEPHONY_SERVICE);
         String networkOperator = telephonyManager.getNetworkOperator();
         if (!TextUtils.isEmpty(networkOperator)) {
             mcc = networkOperator.substring(0, 3);
             mnc = networkOperator.substring(3);
             Log.i(LOG_TAG, "using values for mnc, mcc: " + mnc + "," + mcc);
         } else {
             Log.e(LOG_TAG, "Invalid networkOperator: " + networkOperator);
             return null;
         }
         Cursor findCursor = null;
         try {
             // In the current design, MVNOs are not supported. If we decide to support them,
             // we'll need to add to this CL.
             ContentResolver mContentResolver = mContext.getContentResolver();
             String[] columns = {Telephony.CarrierColumns.PUBLIC_KEY,
                     Telephony.CarrierColumns.EXPIRATION_TIME,
                     Telephony.CarrierColumns.KEY_IDENTIFIER};
             findCursor = mContentResolver.query(Telephony.CarrierColumns.CONTENT_URI, columns,
                     "mcc=? and mnc=? and key_type=?",
                     new String[]{mcc, mnc, String.valueOf(keyType)}, null);
             if (findCursor == null || !findCursor.moveToFirst()) {
                 Log.d(LOG_TAG, "No rows found for keyType: " + keyType);
                 return null;
             }
             if (findCursor.getCount() > 1) {
                 Log.e(LOG_TAG, "More than 1 row found for the keyType: " + keyType);
             }
             byte[] carrier_key = findCursor.getBlob(0);
             Date expirationTime = new Date(findCursor.getLong(1));
             String keyIdentifier = findCursor.getString(2);
             return new ImsiEncryptionInfo(mcc, mnc, keyType, keyIdentifier, carrier_key,
                     expirationTime);
         } catch (IllegalArgumentException e) {
             Log.e(LOG_TAG, "Bad arguments:" + e);
         } catch (Exception e) {
             Log.e(LOG_TAG, "Query failed:" + e);
         } finally {
             if (findCursor != null) {
                 findCursor.close();
             }
         }
         return null;
     }

     /**
      * Inserts or update the Carrier Key in the database
      * @param imsiEncryptionInfo ImsiEncryptionInfo object.
      * @param mContext Context.
      */
     public static void updateOrInsertCarrierKey(ImsiEncryptionInfo imsiEncryptionInfo,
                                                 Context mContext) {
         byte[] keyBytes = imsiEncryptionInfo.getPublicKey().getEncoded();
         ContentResolver mContentResolver = mContext.getContentResolver();
         // In the current design, MVNOs are not supported. If we decide to support them,
         // we'll need to add to this CL.
         ContentValues contentValues = new ContentValues();
         contentValues.put(Telephony.CarrierColumns.MCC, imsiEncryptionInfo.getMcc());
         contentValues.put(Telephony.CarrierColumns.MNC, imsiEncryptionInfo.getMnc());
         contentValues.put(Telephony.CarrierColumns.KEY_TYPE,
                 imsiEncryptionInfo.getKeyType());
         contentValues.put(Telephony.CarrierColumns.KEY_IDENTIFIER,
                 imsiEncryptionInfo.getKeyIdentifier());
         contentValues.put(Telephony.CarrierColumns.PUBLIC_KEY, keyBytes);
         contentValues.put(Telephony.CarrierColumns.EXPIRATION_TIME,
                 imsiEncryptionInfo.getExpirationTime().getTime());
         try {
             Log.i(LOG_TAG, "Inserting imsiEncryptionInfo into db");
             mContentResolver.insert(Telephony.CarrierColumns.CONTENT_URI, contentValues);
         } catch (SQLiteConstraintException e) {
             Log.i(LOG_TAG, "Insert failed, updating imsiEncryptionInfo into db");
             ContentValues updatedValues = new ContentValues();
             updatedValues.put(Telephony.CarrierColumns.PUBLIC_KEY, keyBytes);
             updatedValues.put(Telephony.CarrierColumns.EXPIRATION_TIME,
                     imsiEncryptionInfo.getExpirationTime().getTime());
             updatedValues.put(Telephony.CarrierColumns.KEY_IDENTIFIER,
                     imsiEncryptionInfo.getKeyIdentifier());
             try {
                 int nRows = mContentResolver.update(Telephony.CarrierColumns.CONTENT_URI,
                         updatedValues,
                         "mcc=? and mnc=? and key_type=?", new String[]{
                                 imsiEncryptionInfo.getMcc(),
                                 imsiEncryptionInfo.getMnc(),
                                 String.valueOf(imsiEncryptionInfo.getKeyType())});
                 if (nRows == 0) {
                     Log.d(LOG_TAG, "Error updating values:" + imsiEncryptionInfo);
                 }
             } catch (Exception ex) {
                 Log.d(LOG_TAG, "Error updating values:" + imsiEncryptionInfo + ex);
             }
         }  catch (Exception e) {
             Log.d(LOG_TAG, "Error inserting/updating values:" + imsiEncryptionInfo + e);
         }
     }

     /**
      * Sets the 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.
      * @param imsiEncryptionInfo which includes the Key Type, the Public Key
      *        {@link java.security.PublicKey} and the Key Identifier.
      *        The keyIdentifier Attribute value pair that helps a server locate
      *        the private key to decrypt the permanent identity.
      * @param mContext Context.
      */
     public static void setCarrierInfoForImsiEncryption(ImsiEncryptionInfo imsiEncryptionInfo,
                                                        Context mContext) {
         Log.i(LOG_TAG, "inserting carrier key: " + imsiEncryptionInfo);
         updateOrInsertCarrierKey(imsiEncryptionInfo, mContext);
         //todo send key to modem. Will be done in a subsequent CL.
     }

     /**
      * Resets the Carrier Keys in the database. This involves 2 steps:
      *  1. Delete the keys from the database.
      *  2. Send an intent to download new Certificates.
      * @param context Context
      * @param mPhoneId phoneId
      *
      */
     public void resetCarrierKeysForImsiEncryption(Context context, int mPhoneId) {
         Log.i(LOG_TAG, "resetting carrier key");
         // Check rate limit.
         long now = System.currentTimeMillis();
         if (now - mLastAccessResetCarrierKey < RESET_CARRIER_KEY_RATE_LIMIT) {
             Log.i(LOG_TAG, "resetCarrierKeysForImsiEncryption: Access rate exceeded");
             return;
         }
         mLastAccessResetCarrierKey = now;
         deleteCarrierInfoForImsiEncryption(context);
         Intent resetIntent = new Intent(TelephonyIntents.ACTION_CARRIER_CERTIFICATE_DOWNLOAD);
         resetIntent.putExtra(PhoneConstants.PHONE_KEY, mPhoneId);
         context.sendBroadcastAsUser(resetIntent, UserHandle.ALL);
     }

     /**
      * Deletes all the keys for a given Carrier from the device keystore.
      * @param context Context
      */
     public static void deleteCarrierInfoForImsiEncryption(Context context) {
         Log.i(LOG_TAG, "deleting carrier key from db");
         String mcc = "";
         String mnc = "";
         final TelephonyManager telephonyManager =
                 (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
         String simOperator = telephonyManager.getSimOperator();
         if (!TextUtils.isEmpty(simOperator)) {
             mcc = simOperator.substring(0, 3);
             mnc = simOperator.substring(3);
         } else {
             Log.e(LOG_TAG, "Invalid networkOperator: " + simOperator);
             return;
         }
         ContentResolver mContentResolver = context.getContentResolver();
         try {
             String whereClause = "mcc=? and mnc=?";
             String[] whereArgs = new String[] { mcc, mnc };
             mContentResolver.delete(Telephony.CarrierColumns.CONTENT_URI, whereClause, whereArgs);
         } catch (Exception e) {
             Log.e(LOG_TAG, "Delete failed" + e);
         }
     }

     /**
      * Deletes all the keys from the device keystore.
      * @param context Context
      */
     public static void deleteAllCarrierKeysForImsiEncryption(Context context) {
         Log.i(LOG_TAG, "deleting ALL carrier keys from db");
         ContentResolver mContentResolver = context.getContentResolver();
         try {
             mContentResolver.delete(Telephony.CarrierColumns.CONTENT_URI, null, null);
         } catch (Exception e) {
             Log.e(LOG_TAG, "Delete failed" + e);
         }
     }
 }
	/*
	* Copyright (C) 2017 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.internal.telephony;

	import android.content.ContentResolver;
	import android.content.ContentValues;
	import android.content.Context;
	import android.content.Intent;
	import android.database.Cursor;
	import android.database.sqlite.SQLiteConstraintException;
	import android.os.UserHandle;
	import android.provider.Telephony;
	import android.telephony.ImsiEncryptionInfo;
	import android.telephony.TelephonyManager;
	import android.text.TextUtils;
	import android.util.Log;

	import java.util.Date;

	/**
	* This class provides methods to retreive information from the CarrierKeyProvider.
	*/
	public class CarrierInfoManager {
	private static final String LOG_TAG = "CarrierInfoManager";
	private static final String KEY_TYPE = "KEY_TYPE";

	/*
	* Rate limit (in milliseconds) the number of times the Carrier keys can be reset.
	* Do it at most once every 12 hours.
	*/
	private static final int RESET_CARRIER_KEY_RATE_LIMIT = 12 * 60 * 60 * 1000;

	// Last time the resetCarrierKeysForImsiEncryption API was called successfully.
	private long mLastAccessResetCarrierKey = 0;

	/**
	* Returns Carrier specific information that will be used to encrypt the IMSI and IMPI.
	* @param keyType whether the key is being used for WLAN or ePDG.
	* @param mContext
	* @return ImsiEncryptionInfo which contains the information, including the public key, to be
	* used for encryption.
	*/
	public static ImsiEncryptionInfo getCarrierInfoForImsiEncryption(int keyType,
	Context mContext) {
	String mcc = "";
	String mnc = "";
	final TelephonyManager telephonyManager =
	(TelephonyManager) mContext.getSystemService(Context.TELEPHONY_SERVICE);
	String networkOperator = telephonyManager.getNetworkOperator();
	if (!TextUtils.isEmpty(networkOperator)) {
	mcc = networkOperator.substring(0, 3);
	mnc = networkOperator.substring(3);
	Log.i(LOG_TAG, "using values for mnc, mcc: " + mnc + "," + mcc);
	} else {
	Log.e(LOG_TAG, "Invalid networkOperator: " + networkOperator);
	return null;
	}
	Cursor findCursor = null;
	try {
	// In the current design, MVNOs are not supported. If we decide to support them,
	// we'll need to add to this CL.
	ContentResolver mContentResolver = mContext.getContentResolver();
	String[] columns = {Telephony.CarrierColumns.PUBLIC_KEY,
	Telephony.CarrierColumns.EXPIRATION_TIME,
	Telephony.CarrierColumns.KEY_IDENTIFIER};
	findCursor = mContentResolver.query(Telephony.CarrierColumns.CONTENT_URI, columns,
	"mcc=? and mnc=? and key_type=?",
	new String[]{mcc, mnc, String.valueOf(keyType)}, null);
	if (findCursor == null \|\| !findCursor.moveToFirst()) {
	Log.d(LOG_TAG, "No rows found for keyType: " + keyType);
	return null;
	}
	if (findCursor.getCount() > 1) {
	Log.e(LOG_TAG, "More than 1 row found for the keyType: " + keyType);
	}
	byte[] carrier_key = findCursor.getBlob(0);
	Date expirationTime = new Date(findCursor.getLong(1));
	String keyIdentifier = findCursor.getString(2);
	return new ImsiEncryptionInfo(mcc, mnc, keyType, keyIdentifier, carrier_key,
	expirationTime);
	} catch (IllegalArgumentException e) {
	Log.e(LOG_TAG, "Bad arguments:" + e);
	} catch (Exception e) {
	Log.e(LOG_TAG, "Query failed:" + e);
	} finally {
	if (findCursor != null) {
	findCursor.close();
	}
	}
	return null;
	}

	/**
	* Inserts or update the Carrier Key in the database
	* @param imsiEncryptionInfo ImsiEncryptionInfo object.
	* @param mContext Context.
	*/
	public static void updateOrInsertCarrierKey(ImsiEncryptionInfo imsiEncryptionInfo,
	Context mContext) {
	byte[] keyBytes = imsiEncryptionInfo.getPublicKey().getEncoded();
	ContentResolver mContentResolver = mContext.getContentResolver();
	// In the current design, MVNOs are not supported. If we decide to support them,
	// we'll need to add to this CL.
	ContentValues contentValues = new ContentValues();
	contentValues.put(Telephony.CarrierColumns.MCC, imsiEncryptionInfo.getMcc());
	contentValues.put(Telephony.CarrierColumns.MNC, imsiEncryptionInfo.getMnc());
	contentValues.put(Telephony.CarrierColumns.KEY_TYPE,
	imsiEncryptionInfo.getKeyType());
	contentValues.put(Telephony.CarrierColumns.KEY_IDENTIFIER,
	imsiEncryptionInfo.getKeyIdentifier());
	contentValues.put(Telephony.CarrierColumns.PUBLIC_KEY, keyBytes);
	contentValues.put(Telephony.CarrierColumns.EXPIRATION_TIME,
	imsiEncryptionInfo.getExpirationTime().getTime());
	try {
	Log.i(LOG_TAG, "Inserting imsiEncryptionInfo into db");
	mContentResolver.insert(Telephony.CarrierColumns.CONTENT_URI, contentValues);
	} catch (SQLiteConstraintException e) {
	Log.i(LOG_TAG, "Insert failed, updating imsiEncryptionInfo into db");
	ContentValues updatedValues = new ContentValues();
	updatedValues.put(Telephony.CarrierColumns.PUBLIC_KEY, keyBytes);
	updatedValues.put(Telephony.CarrierColumns.EXPIRATION_TIME,
	imsiEncryptionInfo.getExpirationTime().getTime());
	updatedValues.put(Telephony.CarrierColumns.KEY_IDENTIFIER,
	imsiEncryptionInfo.getKeyIdentifier());
	try {
	int nRows = mContentResolver.update(Telephony.CarrierColumns.CONTENT_URI,
	updatedValues,
	"mcc=? and mnc=? and key_type=?", new String[]{
	imsiEncryptionInfo.getMcc(),
	imsiEncryptionInfo.getMnc(),
	String.valueOf(imsiEncryptionInfo.getKeyType())});
	if (nRows == 0) {
	Log.d(LOG_TAG, "Error updating values:" + imsiEncryptionInfo);
	}
	} catch (Exception ex) {
	Log.d(LOG_TAG, "Error updating values:" + imsiEncryptionInfo + ex);
	}
	} catch (Exception e) {
	Log.d(LOG_TAG, "Error inserting/updating values:" + imsiEncryptionInfo + e);
	}
	}

	/**
	* Sets the 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.
	* @param imsiEncryptionInfo which includes the Key Type, the Public Key
	* {@link java.security.PublicKey} and the Key Identifier.
	* The keyIdentifier Attribute value pair that helps a server locate
	* the private key to decrypt the permanent identity.
	* @param mContext Context.
	*/
	public static void setCarrierInfoForImsiEncryption(ImsiEncryptionInfo imsiEncryptionInfo,
	Context mContext) {
	Log.i(LOG_TAG, "inserting carrier key: " + imsiEncryptionInfo);
	updateOrInsertCarrierKey(imsiEncryptionInfo, mContext);
	//todo send key to modem. Will be done in a subsequent CL.
	}

	/**
	* Resets the Carrier Keys in the database. This involves 2 steps:
	* 1. Delete the keys from the database.
	* 2. Send an intent to download new Certificates.
	* @param context Context
	* @param mPhoneId phoneId
	*
	*/
	public void resetCarrierKeysForImsiEncryption(Context context, int mPhoneId) {
	Log.i(LOG_TAG, "resetting carrier key");
	// Check rate limit.
	long now = System.currentTimeMillis();
	if (now - mLastAccessResetCarrierKey < RESET_CARRIER_KEY_RATE_LIMIT) {
	Log.i(LOG_TAG, "resetCarrierKeysForImsiEncryption: Access rate exceeded");
	return;
	}
	mLastAccessResetCarrierKey = now;
	deleteCarrierInfoForImsiEncryption(context);
	Intent resetIntent = new Intent(TelephonyIntents.ACTION_CARRIER_CERTIFICATE_DOWNLOAD);
	resetIntent.putExtra(PhoneConstants.PHONE_KEY, mPhoneId);
	context.sendBroadcastAsUser(resetIntent, UserHandle.ALL);
	}

	/**
	* Deletes all the keys for a given Carrier from the device keystore.
	* @param context Context
	*/
	public static void deleteCarrierInfoForImsiEncryption(Context context) {
	Log.i(LOG_TAG, "deleting carrier key from db");
	String mcc = "";
	String mnc = "";
	final TelephonyManager telephonyManager =
	(TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
	String simOperator = telephonyManager.getSimOperator();
	if (!TextUtils.isEmpty(simOperator)) {
	mcc = simOperator.substring(0, 3);
	mnc = simOperator.substring(3);
	} else {
	Log.e(LOG_TAG, "Invalid networkOperator: " + simOperator);
	return;
	}
	ContentResolver mContentResolver = context.getContentResolver();
	try {
	String whereClause = "mcc=? and mnc=?";
	String[] whereArgs = new String[] { mcc, mnc };
	mContentResolver.delete(Telephony.CarrierColumns.CONTENT_URI, whereClause, whereArgs);
	} catch (Exception e) {
	Log.e(LOG_TAG, "Delete failed" + e);
	}
	}

	/**
	* Deletes all the keys from the device keystore.
	* @param context Context
	*/
	public static void deleteAllCarrierKeysForImsiEncryption(Context context) {
	Log.i(LOG_TAG, "deleting ALL carrier keys from db");
	ContentResolver mContentResolver = context.getContentResolver();
	try {
	mContentResolver.delete(Telephony.CarrierColumns.CONTENT_URI, null, null);
	} catch (Exception e) {
	Log.e(LOG_TAG, "Delete failed" + e);
	}
	}
	}