com.darwinsys.security.DESCrypter Maven / Gradle / Ivy
package com.darwinsys.security;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.KeySpec;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.PBEParameterSpec;
/**
* DES crypt/decrypt using JSSE.
* @author Original from Patrick Chan's Programmer's Almanac
*/
public class DESCrypter {
private Cipher dcipher;
private Cipher ecipher;
/** 8-byte Salt for DES: this class is set up for general use;
* for some applications, could increase security by choosing
* a different random salt on every invocation (but then need
* to track the chosen salt if decryption must be done later).
* Could just export the SecretKey in that case
*/
private byte[] salt = {
(byte) 0xA9, (byte) 0x9B, (byte) 0xC8, (byte) 0x32,
(byte) 0x56, (byte) 0x35, (byte) 0xE3, (byte) 0x03,
};
private final int iterationCount = 17;
private final SecretKey key;
/**
* Construct a DESCrypter for the given password
* @param passPhrase The given password, as input
*/
public DESCrypter(String passPhrase) {
try {
// Create the SecretKey object
KeySpec keySpec = new PBEKeySpec(passPhrase.toCharArray(), salt,
iterationCount);
key = SecretKeyFactory.getInstance("PBEWithMD5AndDES")
.generateSecret(keySpec);
// And the Cipher objects
ecipher = Cipher.getInstance(key.getAlgorithm());
dcipher = Cipher.getInstance(key.getAlgorithm());
// Prepare the parameter for the ciphers
AlgorithmParameterSpec paramSpec = new PBEParameterSpec(salt,
iterationCount);
// Create the ciphers
ecipher.init(Cipher.ENCRYPT_MODE, key, paramSpec);
dcipher.init(Cipher.DECRYPT_MODE, key, paramSpec);
} catch (Throwable e) {
throw new RuntimeException("DESCrypter: Constructor failure: " + e);
}
}
private final static String PADDING = " ";
/**
* Encrypt the given string using DES
* @param str The input string
* @return The string, encrypted.
*/
public String encrypt(String str) {
try {
// Encode the string into bytes using utf-8
byte[] utf8 = str.getBytes("UTF8");
// Encrypt
byte[] enc = ecipher.doFinal(utf8);
// Encode bytes to base64 to get a string
final String encoded = Base64Coder.encodeLines(enc);
final int n = encoded.length();
System.out.println("Encoded length = " + n);
return encoded;
} catch (Throwable e) {
throw new RuntimeException("Encryption failure: " + e);
}
}
/**
* Decrypt the given string
* @param str The string to be decrypted
* @return the decrypted string
*/
public String decrypt(String str) {
try {
// Decode base64 to get bytes
byte[] dec = Base64Coder.decode(str);
// Decrypt
byte[] utf8 = dcipher.doFinal(dec);
// Decode using utf-8
return new String(utf8, "UTF8");
} catch (Throwable e) {
throw new RuntimeException("Decryption failure: " + e, e);
}
}
}