padded cypher, converting output correctly to hex and back.
I'm using the code below to encrypt string and get a hex representation from the encrypted string.
This way I can save that hex representation in a properties file.
Later I have to decrypt the hex representation back to the original string.
It works, but only when using certain values.
When using :
privatefinalstaticchar[] pwd ="m001uasterpasswocvgcr".toCharArray();
it works.
When using:
privatefinalstaticchar[] pwd ="m001uasterpasswocvgcrg".toCharArray();
It gives me the following error:
javax.crypto.IllegalBlockSizeException: Input length must be multiple of 8 when decrypting with padded cipher
at com.sun.crypto.provider.SunJCE_f.b(DashoA13*..)
at com.sun.crypto.provider.SunJCE_f.b(DashoA13*..)
at com.sun.crypto.provider.SunJCE_ab.b(DashoA13*..)
at com.sun.crypto.provider.PBEWithMD5AndDESCipher.engineDoFinal(DashoA13*..)
at javax.crypto.Cipher.doFinal(DashoA13*..)
at foldersync.dataAccess.clsStringEncryption.decrypt(clsStringEncryption.java:121)
at foldersync.dataAccess.clsStringEncryption.main(clsStringEncryption.java:85)
Where am I going wrong? you can give feedback on the rest of the code 2. because I'm lost in Java's way of handling encryption.
Full test code below: (please don't mind the half baked singleton design)
import java.math.BigInteger;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.spec.InvalidKeySpecException;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.PBEParameterSpec;
/**
*
* @author finalbeta
*/
publicclass clsStringEncryption{
privatestatic PBEParameterSpec algorithm;
privatestatic PBEKeySpec pbeKeySpec;
privatestatic SecretKeyFactory keyBuilder;
privatestatic SecretKey key;
privatestatic Cipher pbeCipher;
publicstaticint iteration = 128;
publicstaticbyte[] salt ={(byte)0xc7, (byte)0x73, (byte)0x21, (byte)0x8c, (byte)0x7e, (byte)0xc8, (byte)0xee, (byte)0x99};
privatefinalstaticchar[] pwd ="m001uasterpasswocvgcr".toCharArray();
/**
* Singleton to create key and cipher, but keep it private since everything can be static anyway.
*/
privatestaticfinal clsStringEncryption instance =new clsStringEncryption();
private clsStringEncryption(){
algorithm =new PBEParameterSpec(salt, iteration);
pbeKeySpec =new PBEKeySpec(pwd);
try{
//create key
keyBuilder = SecretKeyFactory.getInstance("PBEWithMD5AndDES");
key = keyBuilder.generateSecret(pbeKeySpec);
}catch (NoSuchAlgorithmException ex){
ex.printStackTrace();
}catch (InvalidKeySpecException ex){
ex.printStackTrace();
}
try{
//create cipher
pbeCipher = Cipher.getInstance("PBEWithMD5AndDES");
}catch (NoSuchAlgorithmException ex){
ex.printStackTrace();
}catch (NoSuchPaddingException ex){
ex.printStackTrace();
}
}
privatestatic String asHex (byte buf[]){
StringBuffer strbuf =new StringBuffer(buf.length * 2);
int i;
for (i = 0; i < buf.length; i++){
if (((int) buf[i] & 0xff) < 0x10)
strbuf.append("0");
strbuf.append(Long.toString((int) buf[i] & 0xff, 16));
}
return strbuf.toString();
}
privatestaticbyte[] fromHex (String buff){
returnnew BigInteger(buff, 16).toByteArray();
}
publicstaticvoid main(String[] args)throws Exception{
String mypass ="passwordtoencrypt";
System.out.println(encrypt(mypass));
System.out.println(decrypt(encrypt(mypass)));
}
/**
* @return Hex representation of the encrypted String
*/
publicstatic String encrypt(String text){
algorithm =new PBEParameterSpec(salt, iteration);
try{
//init cipher
pbeCipher.init(Cipher.ENCRYPT_MODE, key, algorithm);
//encrypt
byte[] textTranslated = pbeCipher.doFinal(text.getBytes());
//convert byte to String and return
return asHex(textTranslated);
}catch(Exception e){
e.printStackTrace();
}
returnnull;
}
/**
* @return Decripted String from a Hex representation.
*/
publicstatic String decrypt(String text){
try{
//init cipher
pbeCipher.init(Cipher.DECRYPT_MODE, key, algorithm);
}catch (InvalidKeyException ex){
ex.printStackTrace();
}catch (InvalidAlgorithmParameterException ex){
ex.printStackTrace();
}
try{
byte buffer[] = fromHex(text);
returnnew String(pbeCipher.doFinal(buffer));
}catch (IllegalBlockSizeException ex){
ex.printStackTrace();
returnnull;
}catch (BadPaddingException ex){
ex.printStackTrace();
returnnull;
}
}
}
