reworked backup service

* automatically save database encrypted to local storage at 4 am each day
* run backup import in new thread

1 files changed, 73 insertions, 0 deletions

diff --git a/src/main/java/de/pixart/messenger/utils/EncryptDecryptFile.java b/src/main/java/de/pixart/messenger/utils/EncryptDecryptFile.java
new file mode 100644
index 000000000..fd9392132
--- /dev/null
+++ b/src/main/java/de/pixart/messenger/utils/EncryptDecryptFile.java
@@ -0,0 +1,73 @@
+package de.pixart.messenger.utils;
+
+import android.util.Log;
+
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.security.InvalidKeyException;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.Arrays;
+
+import javax.crypto.Cipher;
+import javax.crypto.CipherInputStream;
+import javax.crypto.CipherOutputStream;
+import javax.crypto.NoSuchPaddingException;
+import javax.crypto.spec.SecretKeySpec;
+
+import de.pixart.messenger.Config;
+
+public class EncryptDecryptFile {
+    private static String cipher_mode = "AES/ECB/PKCS5Padding";
+
+    public static void encrypt(FileInputStream iFile, FileOutputStream oFile, String iKey) throws IOException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException {
+        byte[] key = iKey.getBytes("UTF-8");
+        Log.d(Config.LOGTAG, "Cipher key: " + Arrays.toString(key));
+        MessageDigest sha = MessageDigest.getInstance("SHA-1");
+        Log.d(Config.LOGTAG, "Cipher sha: " + sha.toString());
+        key = sha.digest(key);
+        Log.d(Config.LOGTAG, "Cipher sha key: " + Arrays.toString(key));
+        key = Arrays.copyOf(key, 16); // use only first 128 bit
+        Log.d(Config.LOGTAG, "Cipher sha key 16 bytes: " + Arrays.toString(key));
+        SecretKeySpec sks = new SecretKeySpec(key, "AES");
+        Cipher cipher = Cipher.getInstance(cipher_mode);
+        cipher.init(Cipher.ENCRYPT_MODE, sks);
+        Log.d(Config.LOGTAG, "Cipher IV: " + Arrays.toString(cipher.getIV()));
+        CipherOutputStream cos = new CipherOutputStream(oFile, cipher);
+        Log.d(Config.LOGTAG, "Encryption with: " + cos.toString());
+        int b;
+        byte[] d = new byte[8];
+        while ((b = iFile.read(d)) != -1) {
+            cos.write(d, 0, b);
+        }
+        cos.flush();
+        cos.close();
+        iFile.close();
+    }
+
+    public static void decrypt(FileInputStream iFile, FileOutputStream oFile, String iKey) throws IOException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException {
+        byte[] key = iKey.getBytes("UTF-8");
+        Log.d(Config.LOGTAG, "Cipher key: " + Arrays.toString(key));
+        MessageDigest sha = MessageDigest.getInstance("SHA-1");
+        Log.d(Config.LOGTAG, "Cipher sha: " + sha.toString());
+        key = sha.digest(key);
+        Log.d(Config.LOGTAG, "Cipher sha key: " + Arrays.toString(key));
+        key = Arrays.copyOf(key, 16); // use only first 128 bit
+        Log.d(Config.LOGTAG, "Cipher sha key 16 bytes: " + Arrays.toString(key));
+        SecretKeySpec sks = new SecretKeySpec(key, "AES");
+        Cipher cipher = Cipher.getInstance(cipher_mode);
+        cipher.init(Cipher.DECRYPT_MODE, sks);
+        Log.d(Config.LOGTAG, "Cipher IV: " + Arrays.toString(cipher.getIV()));
+        CipherInputStream cis = new CipherInputStream(iFile, cipher);
+        Log.d(Config.LOGTAG, "Decryption with: " + cis.toString());
+        int b;
+        byte[] d = new byte[8];
+        while ((b = cis.read(d)) != -1) {
+            oFile.write(d, 0, b);
+        }
+        oFile.flush();
+        oFile.close();
+        cis.close();
+    }
+}