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-rw-r--r--src/main/java/de/thedevstack/conversationsplus/utils/SimpleCryptoUtil.java110
1 files changed, 110 insertions, 0 deletions
diff --git a/src/main/java/de/thedevstack/conversationsplus/utils/SimpleCryptoUtil.java b/src/main/java/de/thedevstack/conversationsplus/utils/SimpleCryptoUtil.java
new file mode 100644
index 00000000..0a8c80d1
--- /dev/null
+++ b/src/main/java/de/thedevstack/conversationsplus/utils/SimpleCryptoUtil.java
@@ -0,0 +1,110 @@
+package de.thedevstack.conversationsplus.utils;
+
+
+import java.security.InvalidKeyException;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+
+import javax.crypto.BadPaddingException;
+import javax.crypto.Cipher;
+import javax.crypto.IllegalBlockSizeException;
+import javax.crypto.NoSuchPaddingException;
+import javax.crypto.SecretKey;
+import javax.crypto.spec.SecretKeySpec;
+
+/**
+ *
+ */
+public final class SimpleCryptoUtil {
+
+ public static String encrypt(String seed, String cleartext) {
+ String result = null;
+ if (null != seed && null != cleartext) {
+ try {
+ byte[] rawKey = getRawKey(seed.getBytes());
+ byte[] encryptedBytes = encrypt(rawKey, cleartext.getBytes());
+ result = toHex(encryptedBytes);
+ } catch (NoSuchAlgorithmException | InvalidKeyException | IllegalBlockSizeException | BadPaddingException | NoSuchPaddingException e) {
+ // FIXME
+ }
+ }
+
+ return result;
+ }
+
+ public static String decrypt(String seed, String encrypted) {
+ String result = null;
+ if (null != seed && null != encrypted) {
+ try {
+ byte[] rawKey = getRawKey(seed.getBytes());
+ byte[] enc = toByte(encrypted);
+ byte[] decryptedBytes = decrypt(rawKey, enc);
+ result = new String(decryptedBytes);
+ } catch (NoSuchAlgorithmException | InvalidKeyException | IllegalBlockSizeException | BadPaddingException | NoSuchPaddingException e) {
+ // FIXME
+ }
+ }
+
+ return result;
+ }
+
+ private static byte[] encrypt(byte[] raw, byte[] clear) throws IllegalBlockSizeException, BadPaddingException, InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException {
+ byte[] encrypted = doCipherOperation(raw, clear, Cipher.ENCRYPT_MODE);
+ return encrypted;
+ }
+
+ private static byte[] decrypt(byte[] raw, byte[] encrypted) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
+ byte[] decrypted = doCipherOperation(raw, encrypted, Cipher.DECRYPT_MODE);
+ return decrypted;
+ }
+
+ private static byte[] doCipherOperation(byte[] raw, byte[] input, int mode) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
+ SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
+ Cipher cipher = Cipher.getInstance("AES");
+ cipher.init(mode, skeySpec);
+
+ return cipher.doFinal(input);
+ }
+
+ private static byte[] getRawKey(byte[] seed) throws NoSuchAlgorithmException {
+ MessageDigest md = MessageDigest.getInstance("MD5");
+ byte[] md5Bytes = md.digest(seed); // 128 Bit = 16 byte
+ SecretKey skey = new SecretKeySpec(md5Bytes, "AES");
+ byte[] raw = skey.getEncoded();
+ return raw;
+ }
+
+ public static byte[] toByte(String hexString) {
+ int len = hexString.length() / 2;
+ byte[] result = new byte[len];
+ for (int i = 0; i < len; i++) {
+ result[i] = Integer.valueOf(hexString.substring(2 * i, 2 * i + 2), 16).byteValue();
+ }
+ return result;
+ }
+
+ public static String toHex(byte[] buf) {
+ if (buf == null) {
+ return null;
+ }
+ StringBuffer result = new StringBuffer(2 * buf.length);
+ for (int i = 0; i < buf.length; i++) {
+ appendHex(result, buf[i]);
+ }
+ return result.toString();
+ }
+
+ private final static String HEX = "0123456789ABCDEF";
+
+ private static void appendHex(StringBuffer sb, byte b) {
+ sb.append(HEX.charAt((b >> 4) & 0x0f)).append(HEX.charAt(b & 0x0f));
+ }
+
+ /**
+ * private constructor to avoid instantiation
+ */
+ private SimpleCryptoUtil() {
+ // private constructor to avoid instantiation
+ }
+}
+