encryption and decryption Key - Android java.security

Android examples for java.security:Encryption and Decryption

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Description

encryption and decryption Key

Demo Code

public class Main {
  private static String key2 = "asdfasdf";
  private static String key1 = "13245";

  public static byte[] hexStr2Bytes(String src) {
    int m = 0, n = 0;
    int l = src.length() / 2;
    byte[] ret = new byte[l];
    for (int i = 0; i < l; i++) {
      m = i * 2 + 1;//  w  w  w  . ja  v a  2 s  .c om
      n = m + 1;
      ret[i] = Byte.decode("0x" + src.substring(i * 2, m) + src.substring(m, n));
    }
    return ret;
  }

  public static String decryptionKey(String password) {
    byte[] keyByte1 = key1.getBytes();
    byte[] keyByte2 = key2.getBytes();
    // password = hexStr2Str(password);
    byte[] pwdByte = hexStr2Bytes(password);

    for (int i = 0; i < pwdByte.length; i++) {
      pwdByte[i] = (byte) (pwdByte[i] ^ keyByte2[i % keyByte2.length]);
    }

    byte[] lastByte = new byte[pwdByte.length - keyByte1.length];
    for (int i = 0; i < lastByte.length; i++) {
      lastByte[i] = pwdByte[i];
    }
    for (int i = 0; i < lastByte.length; i++) {
      lastByte[i] = (byte) (lastByte[i] ^ keyByte1[i % keyByte1.length]);
    }

    return new String(lastByte);
  }

  public static final String bytesToHexString(byte[] bArray) {
    StringBuffer sb = new StringBuffer(bArray.length);
    String sTemp;
    for (int i = 0; i < bArray.length; i++) {
      sTemp = Integer.toHexString(0xFF & bArray[i]);
      if (sTemp.length() < 2)
        sb.append(0);
      sb.append(sTemp.toUpperCase());
    }
    return sb.toString();
  }

  public static String encryptionKey(String password) {
    byte[] keyByte1 = key1.getBytes();
    byte[] keyByte2 = key2.getBytes();
    byte[] pwdByte = password.getBytes();
    for (int i = 0; i < pwdByte.length; i++) {
      pwdByte[i] = (byte) (pwdByte[i] ^ keyByte1[i % keyByte1.length]);
    }
    byte[] countByte = new byte[pwdByte.length + keyByte1.length];
    for (int i = 0; i < countByte.length; i++) {
      if (i < pwdByte.length)
        countByte[i] = pwdByte[i];
      else
        countByte[i] = keyByte1[i - pwdByte.length];
    }
    for (int i = 0; i < countByte.length; i++) {
      countByte[i] = (byte) (countByte[i] ^ keyByte2[i % keyByte2.length]);
    }
    return bytesToHexString(countByte);
  }

}

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