package com.marshalchen.common.uimodule.utils; import android.content.Context; import com.facebook.crypto.Crypto; import com.facebook.crypto.Entity; import com.facebook.crypto.cipher.NativeGCMCipher; import com.facebook.crypto.keychain.KeyChain; import com.facebook.crypto.keychain.SharedPrefsBackedKeyChain; import com.facebook.crypto.mac.NativeMac; import com.facebook.crypto.util.SystemNativeCryptoLibrary; import com.marshalchen.common.commonUtils.fileUtils.FileUtils; import com.marshalchen.common.commonUtils.logUtils.Logs; import java.io.BufferedOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.InputStream; import java.io.OutputStream; import java.util.Arrays; /** * Created by cym on 14-7-22. */ public class CryptoUtils { /** * could be replace by new SharedPrefsBackedKeyChain(context) */ static KeyChain keyChain = new FakeKeyChain(); public static void encryptingContent(Context context, File file, byte[] plainTextBytes) throws Exception { // Creates a new Crypto object with default implementations of // a key chain as well as native library. Crypto crypto = new Crypto( new SharedPrefsBackedKeyChain(context), new SystemNativeCryptoLibrary()); // Check for whether the crypto functionality is available // This might fail if android does not load libaries correctly. if (!crypto.isAvailable()) { return; } OutputStream fileStream = new BufferedOutputStream( new FileOutputStream(file)); // Creates an output stream which encrypts the data as // it is written to it and writes it out to the file. OutputStream outputStream = crypto.getCipherOutputStream( fileStream, new Entity("TEST1")); // Write plaintext to it. outputStream.write(plainTextBytes); outputStream.close(); } public static void decryptingContent(Context context, File file, String newPath) throws Exception { // Get the file to which ciphertext has been written. FileInputStream fileStream = new FileInputStream(file); Crypto crypto = new Crypto( new SharedPrefsBackedKeyChain(context), new SystemNativeCryptoLibrary()); // Creates an input stream which decrypts the data as // it is read from it. InputStream inputStream = crypto.getCipherInputStream( fileStream, new Entity("TEST1")); // Read into a byte array. int read; byte[] buffer = new byte[1024]; // You must read the entire stream to completion. // The verification is done at the end of the stream. // Thus not reading till the end of the stream will cause // a security bug. FileOutputStream fs = new FileOutputStream(newPath); while ((read = inputStream.read(buffer)) != -1) { fs.write(buffer, 0, read); } inputStream.close(); } public static void testCrypto(Context context) { try { CryptoUtils.encryptingContent(context, new File(FileUtils.getCurrentDataPath(context, "test") + "/aaab"), "hehe1".getBytes()); CryptoUtils.decryptingContent(context, new File(FileUtils.getCurrentDataPath(context, "test") + "/aaab"), FileUtils.getCurrentDataPath(context, "test") + "/aaabc"); } catch (Exception e) { e.printStackTrace(); Logs.e(e, ""); } } } class FakeKeyChain implements KeyChain { private final byte[] mKey = new byte[NativeGCMCipher.KEY_LENGTH]; private final byte[] mIV = new byte[NativeGCMCipher.IV_LENGTH]; private final byte[] mMacKey = new byte[NativeMac.KEY_LENGTH]; public static final int NUM_DATA_BYTES = 2752; public static final int KEY_BYTES = 42; public static final int MAC_KEY_BYTES = 44; public static final int IV_BYTES = 43; public static final String ENTITY_NAME = "TEST"; public static final String FAKE_ENTITY_NAME = "FAKE"; public FakeKeyChain() { Arrays.fill(mKey, (byte) KEY_BYTES); Arrays.fill(mIV, (byte) IV_BYTES); Arrays.fill(mMacKey, (byte) MAC_KEY_BYTES); } @Override public byte[] getCipherKey() { return mKey; } @Override public byte[] getMacKey() { return mMacKey; } @Override public byte[] getNewIV() { return mIV; } @Override public void destroyKeys() { } }