java.lang.ArrayIndexOutOfBoundsException：RSA块的数据太多

Question

package studio.uphie.app;

import android.util.Base64;

import java.security.KeyFactory;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

import javax.crypto.Cipher;

/**
 * Created by Uphie on 2016/4/11.
 */
public class RSA {

    private static String RSA = "RSA";

    /**
     *
     * @param text    text to be encrypted
     * @param pub_key rsa public key
     * @return encrypted data in byte-array form
     */
    public static byte[] encryptData(String text, String pub_key) {
        try {
            byte[] data = text.getBytes();
            PublicKey publicKey = getPublicKey(Base64.decode(pub_key.getBytes(), Base64.DEFAULT));

            Cipher cipher = Cipher.getInstance(RSA);
            cipher.init(Cipher.ENCRYPT_MODE, publicKey);
            return cipher.doFinal(data);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     *
     * @param text    text to be decrypted
     * @param pri_key rsa private key
     * @return
     */
    public static byte[] decryptData(String text, String pri_key) {
        try {
            byte[] data = text.getBytes();
            PrivateKey privateKey = getPrivateKey(Base64.decode(pri_key.getBytes(),Base64.DEFAULT));

            Cipher cipher = Cipher.getInstance(RSA);
            cipher.init(Cipher.DECRYPT_MODE, privateKey);
            return cipher.doFinal(data);
        } catch (Exception e) {
            //"java.lang.ArrayIndexOutOfBoundsException: too much data for RSA block" exception occurs here.
            return null;
        }
    }

    /**
     *
     * @param keyBytes
     * @return
     * @throws NoSuchAlgorithmException
     * @throws InvalidKeySpecException
     */
    public static PublicKey getPublicKey(byte[] keyBytes) throws NoSuchAlgorithmException, InvalidKeySpecException {
        X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(RSA);
        return keyFactory.generatePublic(keySpec);
    }

    /**
     *
     * @param keyBytes
     * @return
     * @throws NoSuchAlgorithmException
     * @throws InvalidKeySpecException
     */
    public static PrivateKey getPrivateKey(byte[] keyBytes) throws NoSuchAlgorithmException,
            InvalidKeySpecException {
        PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(RSA);
        return keyFactory.generatePrivate(keySpec);
    }
}

 //encrypt
 byte[] e = RSA.encryptData(text, PUBLIC_KEY);
 String result = Base64.encodeToString(e, Base64.DEFAULT);
 tv_encrypted.setText(result);

 //decrypt
 byte[] d = RSA.decryptData(text, PRIVATE_KEY);
 String result = Base64.encodeToString(d, Base64.DEFAULT);
 tv_decrypted.setText("Decrypted result：\n" + result);

Answer 1

您的代码中缺少了一些步骤，因此无法进行检查。然而，有几条线索暗示了一个问题。您的DecryptData方法接受一个字符串参数，然后调用String.GetBytes()来获取数据，然后对其进行解密。然而，加密的结果是一个字节序列，它不是任何有效字符串的编码。也许您的意思是base64解码输入，而不是调用getBytes()。通常，要执行解密和解码，必须将加密和编码期间执行的步骤反转。因此，如果明文是字节[]，则步骤如下：

byte[]加密byte[]Base64编码字符串。

然后，在解密方向，从Base64字符串开始，必须：