对称加密算法AES和非对称加密RSA

一、对称加密算法AES

/**
 * AES加密算法
 *
 * @Author ykq
 */
public class Aes256 {
    private static String src = "i am ykq";

    public static void main(String[] args) {
        try {
            // AES生成Key
            KeyGenerator keyGenerator = KeyGenerator.getInstance("AES");
            // 初始化长度
            keyGenerator.init(256);
            // 生成key
            SecretKey secretKey = keyGenerator.generateKey();
            // 获取key的byte数组
            byte[] keyByte = secretKey.getEncoded();

            // 对key进行转换
            Key key = new SecretKeySpec(keyByte, "AES");

            // 加密的方式,工作模式,填充方式
            /**
             * 模式说明：
             * 算法/模式/填充                16字节加密后数据长度        不满16字节加密后长度
             * AES/CBC/NoPadding             16                          不支持
             * AES/CBC/PKCS5Padding          32                          16
             * AES/CBC/ISO10126Padding       32                          16
             * AES/CFB/NoPadding             16                          原始数据长度
             * AES/CFB/PKCS5Padding          32                          16
             * AES/CFB/ISO10126Padding       32                          16
             * AES/ECB/NoPadding             16                          不支持
             * AES/ECB/PKCS5Padding          32                          16
             * AES/ECB/ISO10126Padding       32                          16
             * AES/OFB/NoPadding             16                          原始数据长度
             * AES/OFB/PKCS5Padding          32                          16
             * AES/OFB/ISO10126Padding       32                          16
             * AES/PCBC/NoPadding            16                          不支持
             * AES/PCBC/PKCS5Padding         32                          16
             * AES/PCBC/ISO10126Padding      32                          16
             */
            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
            // 加密方式，以key初始化
            cipher.init(Cipher.ENCRYPT_MODE, key);
            byte[] encryptSrc = cipher.doFinal(src.getBytes());
            String encryptStr = Base64.getEncoder().encodeToString(encryptSrc);
            System.out.println("加密结果：" + encryptStr);

            // 对加密的字符串进行解密
            // 以解密方式，对key初始化
            cipher.init(Cipher.DECRYPT_MODE, key);
            byte[] decryptByte = cipher.doFinal(Base64.getDecoder().decode(encryptStr));
            String decryptStr = new String(decryptByte);
            System.out.println("解密结果:" + decryptStr);
        } catch (Exception e) {
            System.out.println("异常：" + e);
        }
    }
}

实现效果：

二、非对称加密算法RSA

public class RSA {
    private static String src = "i am ykq";

    public static void main(String[] args) {
        try {
            // 生产key
            KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
            KeyPair keyPair = keyPairGenerator.generateKeyPair();
            // 生成私钥
            RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) keyPair.getPrivate();
            // 生成公钥
            RSAPublicKey rsaPublicKey = (RSAPublicKey) keyPair.getPublic();

            // 私钥加密
            PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(rsaPrivateKey.getEncoded());
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
            Cipher cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.ENCRYPT_MODE, privateKey);
            byte[] encryptByte = cipher.doFinal(src.getBytes());
            String encryptStr = Base64.getEncoder().encodeToString(encryptByte);
            System.out.println("加密后的字符串：" + encryptStr);

            // 公钥解密
            X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(rsaPublicKey.getEncoded());
            PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);
            cipher.init(Cipher.DECRYPT_MODE, publicKey);
            byte[] decryptByte = cipher.doFinal(Base64.getDecoder().decode(encryptStr));
            System.out.println("解密后的字符串：" + new String(decryptByte));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

实现效果：