我正在尝试在 Java 中使用 RSA 加密。
我正在生成一个公钥并使用它来加密文本。我的问题是，当我两次传入相同的文本和相同的密钥时，加密的结果是不同的。这意味着我不能使用我的加密来测试输入的文本是否等于先前加密的存储结果。
这是我的加密类：
import java.security.InvalidKeyException;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PublicKey;
import java.util.Arrays;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
/**
* The class encrypts text using an RSA algorithm.
*
*/
public class RSAEncryption {
//RSA algorithm
private final String ALGORITHM = "RSA";
/**
* The generateKey method generates a public key for use in RSA encryption.
* @return key a PublicKey for use in RSA encryption.
*/
public PublicKey generateKey(){
KeyPair key = null;
KeyPairGenerator keyGen;
try {
keyGen = KeyPairGenerator.getInstance(ALGORITHM); //gets instance of the alogrithm
keyGen.initialize(1024); //a 1021 bit key
key = keyGen.generateKeyPair(); //makes a pair
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
return key.getPublic(); //returns the public key. Private key never stored.
}
/**
* The encrypt method takes in text and a key and encrypts the text using the RSA encryption algorithm.
* @params text a String, the text to encrypt.
* @params key a PublicKey to use in encryption.
* @returns encryptedText a byte array representing the result of the encryption.
public byte[] encrypt(String text, PublicKey key){
byte[] encryptedText = null;
Cipher cipher;
try {
cipher = Cipher.getInstance(ALGORITHM); //gets instance of RSA
cipher.init(Cipher.ENCRYPT_MODE, key); //in encryption mode with the key
encryptedText = cipher.doFinal(text.getBytes()); //carry out the encryption
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
}
return encryptedText; //return encrypted result
}
/**
* The authenticate method checks if entered text, once encrypted, matches the stored byte[].
* @param text a String, the text to encrypt.
* @param stored a byte[], the result of a prior encryption.
* @param key a PublicKey, a result of the generateKey method.
* @return boolean, true if the text is valid, false otherwise.
*/
public boolean authenticate(String text, byte[] stored, PublicKey key){
byte[] encryptText = encrypt(text,key); //encrypt the entered text
return Arrays.equals(stored, encryptText); //check if the stored and entered byte[] are the same.
}
}
我为此编写了 JUnit 测试：
import static org.junit.Assert.*;
import java.security.PublicKey;
import java.util.Arrays;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
public class RSAEncryptionTest {
RSAEncryption cipher;
String text;
@Before
public void setUp(){
cipher = new RSAEncryption();
text = "text";
}
@Test
public void testEncryptionGenerateKeyGeneratesANewKeyWhenCalled(){
PublicKey key = cipher.generateKey();
assertEquals(false,key.equals(cipher.generateKey()));
}
@Test
public void testEncryptionEncryptMethodRepeatablyEncrypts(){
PublicKey key = cipher.generateKey();
byte[] encrypted = cipher.encrypt(text,key);
Assert.assertArrayEquals(encrypted, cipher.encrypt(text,key));
//test fails
}
@Test
public void testEncryptionAuthenticateMethodReturnsTrueWhenValidTextPassedIn(){
PublicKey key = cipher.generateKey();
byte[] encrypted = cipher.encrypt(text,key);
assertEquals(true,cipher.authenticate(text,encrypted,key));
//test fails
}
@Test
public void testEncryptionAuthenticateMethodReturnsFalseWhenInvalidTextPassedIn(){
PublicKey key = cipher.generateKey();
byte[] encrypted = cipher.encrypt(text,key);
assertEquals(false,cipher.authenticate("text1",encrypted,key));
}
}
第二次和第三次测试失败。
任何想法如何使用 RSA 重复加密文本？