Question

我正在尝试无填充地实现RSA加密。如果我多次加密同一件事，我需要它来获得相同的密文。问题是，即使我似乎设法做到了，密文也无法解密。如果我将“ RSA / ECB / NoPadding”替换为“ RSA”，则下面的代码有效。

import javax.crypto.Cipher;
import java.io.InputStream;
import java.security.*;
import java.util.Base64;

import static java.nio.charset.StandardCharsets.UTF_8;

public class RsaExample {
//https://gist.github.com/nielsutrecht/855f3bef0cf559d8d23e94e2aecd4ede
public static KeyPair generateKeyPair() throws Exception {
    KeyPairGenerator generator = KeyPairGenerator.getInstance("RSA");
    generator.initialize(2048, new SecureRandom());
    KeyPair pair = generator.generateKeyPair();

    return pair;
}

public static KeyPair getKeyPairFromKeyStore() throws Exception {
    //Generated with:
    //  keytool -genkeypair -alias mykey -storepass s3cr3t -keypass s3cr3t -keyalg RSA -keystore keystore.jks

    InputStream ins = RsaExample.class.getResourceAsStream("/keystore.jks");

    KeyStore keyStore = KeyStore.getInstance("JCEKS");
    keyStore.load(ins, "s3cr3t".toCharArray());   //Keystore password
    KeyStore.PasswordProtection keyPassword =       //Key password
            new KeyStore.PasswordProtection("s3cr3t".toCharArray());

    KeyStore.PrivateKeyEntry privateKeyEntry = (KeyStore.PrivateKeyEntry) keyStore.getEntry("mykey", keyPassword);

    java.security.cert.Certificate cert = keyStore.getCertificate("mykey");
    PublicKey publicKey = cert.getPublicKey();
    PrivateKey privateKey = privateKeyEntry.getPrivateKey();

    return new KeyPair(publicKey, privateKey);
}

public static String encrypt(String plainText, PublicKey publicKey) throws Exception {
    Cipher encryptCipher = Cipher.getInstance("RSA/ECB/NoPadding");
    encryptCipher.init(Cipher.ENCRYPT_MODE, publicKey);

    byte[] cipherText = encryptCipher.doFinal(plainText.getBytes(UTF_8));

    return Base64.getEncoder().encodeToString(cipherText);
}

public static String decrypt(String cipherText, PrivateKey privateKey) throws Exception {
    byte[] bytes = Base64.getDecoder().decode(cipherText);

    Cipher decriptCipher = Cipher.getInstance("RSA/ECB/NoPadding");
    decriptCipher.init(Cipher.DECRYPT_MODE, privateKey);

    return new String(decriptCipher.doFinal(bytes), UTF_8);
}

public static String sign(String plainText, PrivateKey privateKey) throws Exception {
    Signature privateSignature = Signature.getInstance("SHA256withRSA");
    privateSignature.initSign(privateKey);
    privateSignature.update(plainText.getBytes(UTF_8));

    byte[] signature = privateSignature.sign();

    return Base64.getEncoder().encodeToString(signature);
}

public static boolean verify(String plainText, String signature, PublicKey publicKey) throws Exception {
    Signature publicSignature = Signature.getInstance("SHA256withRSA");
    publicSignature.initVerify(publicKey);
    publicSignature.update(plainText.getBytes(UTF_8));

    byte[] signatureBytes = Base64.getDecoder().decode(signature);

    return publicSignature.verify(signatureBytes);
}

public static void main(String... argv) throws Exception {
    //First generate a public/private key pair
    KeyPair pair = generateKeyPair();
    //KeyPair pair = getKeyPairFromKeyStore();

    //Our secret message
    String message = "the answer to life the universe and everything";

    //Encrypt the message
    String cipherText = encrypt(message, pair.getPublic());
    System.out.println("Cipher 1="+ cipherText);

    String cipherText2 = encrypt(message, pair.getPublic());
    System.out.println("Cipher 2="+ cipherText2);

    //Now decrypt it
    String decipheredMessage = decrypt(cipherText, pair.getPrivate());
    //System.out.println("Private "+pair.getPrivate().toString());
    System.out.println("Deciphered "+ decipheredMessage);

    //Let's sign our message
    String signature = sign("foobar", pair.getPrivate()); 
    System.out.println("Signature "+signature);
    //Let's check the signature
    boolean isCorrect = verify("foobar", signature, pair.getPublic());
    System.out.println("Signature correct: " + isCorrect);
}
}

任何帮助将不胜感激。

Java RSA，无填充

0 个答案: