Here you go.
This is some old code for a fairly light encryption job. You might want to
adjust the algorithm a bit to use at least SHA (also maybe not use DES).
I think I'd also make the salt mutable based on a second input, but it
really depends on how much you care about protecting what your encrypting.
- Brill
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.PBEParameterSpec;
import android.util.Log;
public class PBECypher {
private static final String TAG = "PBECypher";
private final static String HEX = "0123456789ABCDEF";
private Cipher encryptCipher;
private Cipher decryptCipher;
public PBECypher(char[] password) {
super();
initCiphers(password);
}
private void initCiphers(char password[]) {
PBEKeySpec pbeKeySpec;
PBEParameterSpec pbeParamSpec;
SecretKeyFactory keyFac;
byte[] salt = { (byte) 0xc7, (byte) 0x73, (byte) 0x21, (byte) 0x8c,
(byte) 0x7e, (byte) 0xc8, (byte) 0xee, (byte) 0x99 };
int count = 20;
pbeParamSpec = new PBEParameterSpec(salt, count);
pbeKeySpec = new PBEKeySpec(password);
try {
keyFac = SecretKeyFactory.getInstance("PBEWithMD5AndDES");
SecretKey pbeKey = keyFac.generateSecret(pbeKeySpec);
encryptCipher = Cipher.getInstance("PBEWithMD5AndDES");
decryptCipher = Cipher.getInstance("PBEWithMD5AndDES");
encryptCipher.init(Cipher.ENCRYPT_MODE, pbeKey, pbeParamSpec);
decryptCipher.init(Cipher.DECRYPT_MODE, pbeKey, pbeParamSpec);
} catch (Exception e) {
Log.v(TAG, e.toString());
}
}
public byte[] encrypt(byte[] decrypted) throws Exception {
byte[] output = encryptCipher.doFinal(decrypted);
return output;
}
public byte[] decrypt(byte[] encrypted) throws Exception {
byte[] decrypted = decryptCipher.doFinal(encrypted);
return decrypted;
}
public String encryptString(String decrypted) throws Exception {
byte[] input = decrypted.getBytes("UTF-8");
return toHexFromByte(encrypt(input));
}
public String decryptString(String encrypted) throws Exception {
byte[] input = toByteFromHex(encrypted);
return new String(decrypt(input), "UTF-8");
}
public static String toHex(String txt) {
return toHexFromByte(txt.getBytes());
}
public static String fromHex(String hex) {
return new String(toByteFromHex(hex));
}
public static byte[] toByteFromHex(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 toHexFromByte(byte[] buf) {
if (buf == null) {
return "";
}
StringBuffer result = new StringBuffer(2 * buf.length);
for (int i = 0; i < buf.length; i++) {
appendHex(result, buf[i]);
}
return result.toString();
}
private static void appendHex(StringBuffer sb, byte b) {
sb.append(HEX.charAt((b >> 4) & 0x0f)).append(HEX.charAt(b & 0x0f));
}
}
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