AES加密算法的开源代码

以下是使用Java实现的AES加密算法的开源代码示例：

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.nio.charset.StandardCharsets;
import java.security.Key;

public class AES {

    private static final String ALGORITHM = "AES";
    private static final String TRANSFORMATION = "AES/ECB/PKCS5Padding";

    public static byte[] encrypt(String key, String plaintext) throws Exception {
        Key aesKey = new SecretKeySpec(key.getBytes(StandardCharsets.UTF_8), ALGORITHM);
        Cipher cipher = Cipher.getInstance(TRANSFORMATION);
        cipher.init(Cipher.ENCRYPT_MODE, aesKey);
        return cipher.doFinal(plaintext.getBytes(StandardCharsets.UTF_8));
    }

    public static String decrypt(String key, byte[] ciphertext) throws Exception {
        Key aesKey = new SecretKeySpec(key.getBytes(StandardCharsets.UTF_8), ALGORITHM);
        Cipher cipher = Cipher.getInstance(TRANSFORMATION);
        cipher.init(Cipher.DECRYPT_MODE, aesKey);
        return new String(cipher.doFinal(ciphertext), StandardCharsets.UTF_8);
    }
}

使用示例：

String key = "mykey";
String plaintext = "Hello, world!";
byte[] ciphertext = AES.encrypt(key, plaintext);
String decryptedText = AES.decrypt(key, ciphertext);
System.out.println(decryptedText); // Output: Hello, world!

请注意，此示例使用的是ECB模式和PKCS5Padding填充。对于更高级别的安全性，您可能需要使用其他模式和填充。另外，此示例中的密钥应该更长，并且应该从更安全的源生成。