在投票应用层协议项目的基础上，使用现代密码学算法，使用Java语言，将该应用层协议修改为安全传输的通信过程。 方式一：将投票信息整体进行加解密； 方式二：将报文的某个字段进行加解密；两种方式分别描述，要求包含程序实现思路描述和关键代码的讲解

好的，我会分别为你详细描述两种方式的实现。

方式一：将投票信息整体进行加解密

加密过程：

1. 客户端生成随机密钥K，并使用该密钥对投票信息进行AES对称加密。

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.util.Base64;

public class VoteEncryptor {
    private static final String AES_ALGORITHM = "AES/ECB/PKCS5Padding";
    private static final String CHARSET = "UTF-8";

    public static String encrypt(String voteInfo, String keyStr) throws Exception {
        SecretKeySpec secretKey = new SecretKeySpec(keyStr.substring(0, 16).getBytes(CHARSET), "AES");
        Cipher cipher = Cipher.getInstance(AES_ALGORITHM);
        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
        byte[] encryptedBytes = cipher.doFinal(voteInfo.getBytes(CHARSET));
        return Base64.getEncoder().encodeToString(encryptedBytes);
    }
}

2. 客户端使用RSA公钥对随机密钥K进行非对称加密，并将加密后的密钥K'发送给服务器。

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.security.PrivateKey;
import java.util.Base64;

public class KeyEncryptor {
    private static final String RSA_ALGORITHM = "RSA/ECB/PKCS1Padding";
    private static final String CHARSET = "UTF-8";

    public static String encrypt(String keyStr, PrivateKey privateKey) throws Exception {
        Cipher cipher = Cipher.getInstance(RSA_ALGORITHM);
        cipher.init(Cipher.ENCRYPT_MODE, privateKey);
        byte[] encryptedBytes = cipher.doFinal(keyStr.getBytes(CHARSET));
        return Base64.getEncoder().encodeToString(encryptedBytes);
    }
}

解密过程：

1. 服务器使用RSA私钥对收到的密钥K'进行非对称解密，得到随机密钥K。

import javax.crypto.Cipher;
import java.security.PrivateKey;
import java.util.Base64;

public class KeyDecryptor {
    private static final String RSA_ALGORITHM = "RSA/ECB/PKCS1Padding";
    private static final String CHARSET = "UTF-8";

    public static String decrypt(String ciphertext, PrivateKey privateKey) throws Exception {
        Cipher cipher = Cipher.getInstance(RSA_ALGORITHM);
        cipher.init(Cipher.DECRYPT_MODE, privateKey);
        byte[] decryptedBytes = cipher.doFinal(Base64.getDecoder().decode(ciphertext));
        return new String(decryptedBytes, CHARSET);
    }
}

2. 服务器使用随机密钥K对收到的投票信息进行AES对称解密，得到原始的投票信息。

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.util.Base64;

public class VoteDecryptor {
    private static final String AES_ALGORITHM = "AES/ECB/PKCS5Padding";
    private static final String CHARSET = "UTF-8";

    public static String decrypt(String ciphertext, String keyStr) throws Exception {
        SecretKeySpec secretKey = new SecretKeySpec(keyStr.substring(0, 16).getBytes(CHARSET), "AES");
        Cipher cipher = Cipher.getInstance(AES_ALGORITHM);
        cipher.init(Cipher.DECRYPT_MODE, secretKey);
        byte[] decryptedBytes = cipher.doFinal(Base64.getDecoder().decode(ciphertext));
        return new String(decryptedBytes, CHARSET);
    }
}

方式二：将报文的某个字段进行加解密

加密过程：

1. 客户端生成随机密钥K，并使用该密钥对需要加密的字段进行AES对称加密。

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.util.Base64;

public class FieldEncryptor {
    private static final String AES_ALGORITHM = "AES/ECB/PKCS5Padding";
    private static final String CHARSET = "UTF-8";

    public static String encrypt(String field, String keyStr) throws Exception {
        SecretKeySpec secretKey = new SecretKeySpec(keyStr.substring(0, 16).getBytes(CHARSET), "AES");
        Cipher cipher = Cipher.getInstance(AES_ALGORITHM);
        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
        byte[] encryptedBytes = cipher.doFinal(field.getBytes(CHARSET));
        return Base64.getEncoder().encodeToString(encryptedBytes);
    }
}

2. 客户端使用RSA公钥对随机密钥K进行非对称加密，并将加密后的密钥K'替换原始报文中的对应字段，得到加密后的报文。

import javax.crypto.Cipher;
import java.security.PrivateKey;
import java.util.Base64;
import java.util.Map;

public class KeyExchange {
    private static final String RSA_ALGORITHM = "RSA/ECB/PKCS1Padding";
    private static final String CHARSET = "UTF-8";

    public static Map<String, Object> encryptKey(String keyStr, PrivateKey privateKey, Map<String, Object> voteMsg) throws Exception {
        Cipher cipher = Cipher.getInstance(RSA_ALGORITHM);
        cipher.init(Cipher.ENCRYPT_MODE, privateKey);
        byte[] encryptedBytes = cipher.doFinal(keyStr.getBytes(CHARSET));
        String key = Base64.getEncoder().encodeToString(encryptedBytes);
        voteMsg.put("key", key);
        return voteMsg;
    }
}

解密过程：

1. 服务器使用RSA私钥对收到的密钥K'进行非对称解密，得到随机密钥K。

import javax.crypto.Cipher;
import java.security.PrivateKey;
import java.util.Base64;

public class KeyDecryptor {
    private static final String RSA_ALGORITHM = "RSA/ECB/PKCS1Padding";
    private static final String CHARSET = "UTF-8";

    public static String decrypt(String ciphertext, PrivateKey privateKey) throws Exception {
        Cipher cipher = Cipher.getInstance(RSA_ALGORITHM);
        cipher.init(Cipher.DECRYPT_MODE, privateKey);
        byte[] decryptedBytes = cipher.doFinal(Base64.getDecoder().decode(ciphertext));
        return new String(decryptedBytes, CHARSET);
    }
}

2. 服务器使用随机密钥K对收到的加密字段进行AES对称解密，得到原始的字段。

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.util.Base64;

public class FieldDecryptor {
    private static final String AES_ALGORITHM = "AES/ECB/PKCS5Padding";
    private static final String CHARSET = "UTF-8";

    public static String decrypt(String ciphertext, String keyStr) throws Exception {
        SecretKeySpec secretKey = new SecretKeySpec(keyStr.substring(0, 16).getBytes(CHARSET), "AES");
        Cipher cipher = Cipher.getInstance(AES_ALGORITHM);
        cipher.init(Cipher.DECRYPT_MODE, secretKey);
        byte[] decryptedBytes = cipher.doFinal(Base64.getDecoder().decode(ciphertext));
        return new String(decryptedBytes, CHARSET);
    }
}

以上是两种方式的实现思路和关键代码讲解，希望能对你有所帮助！