RSA和AES用于加密和解密明文（验证密钥）

Question

我的进程:
1。生成对称密钥
2。使用对称密钥
3加密数据。使用RSA
4加密对称密钥。发送加密密钥和数据
5。使用RSA
6解密加密的对称密钥。使用对称密钥
7解密数据。已完成

import java.io.UnsupportedEncodingException;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.util.Arrays;
import java.util.Base64;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

public class AES_RSA {

    private static byte[] key;
    private static SecretKeySpec secretKey;

    public static void main(String[] args){
        try {

            //1. Generate Symmetric Key (AES with 128 bits)
            String password = "123456";
            KeyGenerator generator = KeyGenerator.getInstance("AES");
            generator.init(128); // The AES key size in number of bits

            setKey(password);

            //2. Encrypt plain text using AES
            String plainText = "Please encrypt me urgently...";
            Cipher aesCipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
            aesCipher.init(Cipher.ENCRYPT_MODE, secretKey);
            byte[] byteCipherText = aesCipher.doFinal(plainText.getBytes());

            //3. Encrypt the key using RSA public key
            KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA");
            kpg.initialize(2048);
            KeyPair keyPair = kpg.generateKeyPair();

            PublicKey puKey = keyPair.getPublic();
            PrivateKey prKey = keyPair.getPrivate();

            Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
            cipher.init(Cipher.PUBLIC_KEY, puKey);
            byte[] encryptedKey = cipher.doFinal(secretKey.getEncoded()/*Seceret Key From Step 1*/);

            //4. Send encrypted data (byteCipherText) + encrypted AES Key (encryptedKey)
            //5. On the client side, decrypt symmetric key using RSA private key
            cipher.init(Cipher.PRIVATE_KEY, prKey);
            byte[] decryptedKey = cipher.doFinal(encryptedKey);

            //6. Decrypt the cipher using decrypted symmetric key
            SecretKey originalKey = new SecretKeySpec(decryptedKey , 0, decryptedKey.length, "AES");
            Cipher aesCipher1 = Cipher.getInstance("AES/ECB/PKCS5PADDING");
            aesCipher1.init(Cipher.DECRYPT_MODE, originalKey);
            byte[] bytePlainText = aesCipher1.doFinal(byteCipherText);
            String plainText1 = new String(bytePlainText);

            //7. Done! 'Please encrypt me urgently...'
            System.out.println(plainText1);

        }catch (Exception e) {}
    }


    public static void setKey(String myKey)
    {
        MessageDigest sha = null;
        try {
            key = myKey.getBytes("UTF-8");
            sha = MessageDigest.getInstance("SHA-256");
            key = sha.digest(key);
            key = Arrays.copyOf(key, 16);
            secretKey = new SecretKeySpec(key, "AES");
        }
        catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
    }
}

Answer 1

你的伪步骤是正确的，但你的描述不是。例如，您通常保留RSA私钥，并分发RSA公钥。

而是一些创建更好代码的建议。

>

我建议使用pkcs5来创建基于密码的密钥，而不是简单的哈希。Java的pbekeyspec是一个用于生成此类密钥的类。下面是一个小的示例代码，您可以将其用于setkey()例程（根据需要进行调整）：

SecretKeyFactory skf = SecretKeyFactory.getInstance("AES");
SecretKey key = skf.generateSecret(new PBEKeySpec(password.getBytes("UTF-8"), salt, 10000));