Всем добрый вечер.
Попытался сделать реализацию алгоритма RSA. Написал небольшой тест. Проблема в том что тест срабатывает "через раз". Не могу понять в чем ошибка. Прошу помочь.
RSAKeyGenerator.java
| Код |
package org.jim.crypto.impl.rsa;
import org.jim.crypto.Key;
import org.jim.crypto.KeyGenerator;
import java.math.BigInteger;
import java.util.Random;
/**
* Author: SemenovAn
* Date: Oct 29, 2011
*/
public class RSAKeyGenerator implements KeyGenerator
{
public Object createKey(Object value)
{
BigInteger[] mas = (BigInteger[]) value;
return new Key[]{new RSAKey(mas[0], mas[1])
, new RSAKey(mas[2], mas[3])};
}
/*
* Return array[2] with keys :
* array[0] - public key
* array[1] - private key
* */
public Object generateKeys()
{
Random rnd = new Random();
BigInteger p = BigInteger.probablePrime(512, rnd);
BigInteger q = BigInteger.probablePrime(512, rnd);
BigInteger n = p.multiply(q);
BigInteger fi = p.subtract(BigInteger.ONE).multiply(q.subtract(BigInteger.ONE));
BigInteger e;
while(true){
e = BigInteger.probablePrime(512, rnd);
if ((n .compareTo(e) == 1) && (fi.gcd(e).equals(BigInteger.ONE)))
break;
}
BigInteger d = e.modInverse(fi);
return new Key[] {new RSAKey(e, n),
new RSAKey(d, n)};
}
}
|
RSAChipher.java
| Код |
package org.jim.crypto.impl.rsa;
import org.jim.crypto.Cipher;
import org.jim.crypto.Key;
import java.math.BigInteger;
/**
* Author: SemenovAn
* Date: Oct 29, 2011
*/
public class RSACipher implements Cipher
{
public byte[] encrypt(byte[] source, Key key)
{
BigInteger e = ((PairOfNumbers)key.getKey()).getNumb1();
BigInteger n = ((PairOfNumbers)key.getKey()).getNumb2();
BigInteger val = new BigInteger(source);
val=val.modPow(e, n);
return val.toByteArray();
}
public byte[] decrypt(byte[] source, Key key)
{
BigInteger d = ((PairOfNumbers)key.getKey()).getNumb1();
BigInteger n = ((PairOfNumbers)key.getKey()).getNumb2();
BigInteger val = new BigInteger(source);
val=val.modPow(d, n);
return val.toByteArray();
}
}
|
CryptographerTest ошибка в тесте testRSAAndBlowfishEncDec()
| Код |
package org.jim.crypto;
import org.jim.crypto.impl.rsa.RSACipher;
import org.junit.Test;
import java.io.IOException;
import java.math.BigInteger;
import static junit.framework.Assert.assertEquals;
/**
* Author: SemenovAn
* Date: Oct 29, 2011
*/
public class CryptographerTest
{
private RSACipher rsaCrypto = new RSACipher();
@Test
public void testRSAEncryptDecrypt() throws IOException
{
BigInteger msg = new BigInteger("123456789");
CryptoFacade facade = new CryptoFacade(CryptoFacade.RSA);
Key[] keys = (Key[]) facade.getKey();
Key publicKey = keys[0];
Key privateKey = keys[1];
byte[] etalonBytes = msg.toByteArray();
byte[] encrypt = facade.encode(etalonBytes, publicKey);
byte[] decrypt = facade.decode(encrypt, privateKey);
assertBiteArrays(etalonBytes, decrypt);
assertEquals(msg, new BigInteger(decrypt));
}
@Test
public void testBlowfishEncryptDecrypt() throws IOException
{
// String helloWorld = "Hellow world";
BigInteger test = new BigInteger("123456789123456789");
CryptoFacade facade = new CryptoFacade(CryptoFacade.BLOWFISH);
Key key = (Key) facade.getKey();
byte[] etalonBytes =test.toByteArray();
byte[] encrypt = facade.encode(etalonBytes, key);
byte[] decrypt = facade.decode(encrypt, key);
assertBiteArrays(etalonBytes, decrypt);
}
@Test
public void testRSAAndBlowfishEncDec() throws IOException, ClassNotFoundException
{
// message A -> B
BigInteger test = new BigInteger("123456789123456789");
CryptoFacade rsa = new CryptoFacade("RSA");
CryptoFacade blowfish = new CryptoFacade("BLOWFISH");
Key[] keysA = (Key[]) rsa.getKey();
Key[] keysB = (Key[]) rsa.getKey();
Key openKeyB = keysB[0];
Key privateKeyB = keysB[1];
Key bfKeyA = (Key) blowfish.getKey();
byte[] blowFishKeyForBAsBytes = ((BigInteger)bfKeyA.getKey()).toByteArray();
byte[] encryptBlowFishKeyForB = rsa.encode(blowFishKeyForBAsBytes, openKeyB);
byte[] decodeBlowfishKeyOnB = rsa.decode(encryptBlowFishKeyForB, privateKeyB);
assertBiteArrays(blowFishKeyForBAsBytes, decodeBlowfishKeyOnB);
// assertEquals(bfKeyA.getKey(), new BigInteger(decodeBlowfishKeyOnB));
Key bfKeyAOnBSide = (Key) blowfish.createKey(decodeBlowfishKeyOnB);
byte[] msg = test.toByteArray();
byte[] encryptMsgWithBlowFishForB = blowfish.encode(msg, bfKeyA);
byte[] decryptMsgOnBSideUsingDecryptKeyFromA = blowfish.decode(encryptMsgWithBlowFishForB, bfKeyAOnBSide);
assertBiteArrays(msg, decryptMsgOnBSideUsingDecryptKeyFromA);
assertEquals(test, new BigInteger(decryptMsgOnBSideUsingDecryptKeyFromA));
}
private void assertBiteArrays(byte[] expected, byte[] actual)
{
assertEquals("Length not equals ",
expected.length, actual.length);
for (int i =0 ; i<expected.length; i++)
assertEquals(expected[i], actual[i]);
}
}
|
Ошибка летит следущая:
| Код |
junit.framework.AssertionFailedError: Length not equals expected:<129> but was:<128>
at org.jim.crypto.CryptographerTest.assertBiteArrays(CryptographerTest.java:96)
at org.jim.crypto.CryptographerTest.testRSAAndBlowfishEncDec(CryptographerTest.java:77)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
|
Т.е. дешифрованное сообщение и зашифрованное отличаются по длине, почему такое происходит ?
Подозреваю , проблема в разрядности, но вроде пытаюсь генерить ключи длины 512. |
