c# aes 加密

using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

public class AesEncryption
{
    // AES加密方法
    public static string Encrypt(string plainText, string key)
    {
        byte[] encrypted;
        using (Aes aesAlg = Aes.Create())
        {
            aesAlg.Key = Encoding.UTF8.GetBytes(key.Substring(0, 32)); // 设置密钥
            aesAlg.IV = Encoding.UTF8.GetBytes(key.Substring(0, 16));  // 设置初始化向量

            ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);

            using (MemoryStream msEncrypt = new MemoryStream())
            {
                using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
                {
                    using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
                    {
                        swEncrypt.Write(plainText);
                    }
                    encrypted = msEncrypt.ToArray();
                }
            }
        }

        return Convert.ToBase64String(encrypted); // 返回加密后的字符串
    }

    // AES解密方法
    public static string Decrypt(string cipherText, string key)
    {
        string plaintext = null;
        using (Aes aesAlg = Aes.Create())
        {
            aesAlg.Key = Encoding.UTF8.GetBytes(key.Substring(0, 32));
            aesAlg.IV = Encoding.UTF8.GetBytes(key.Substring(0, 16));

            ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);

            using (MemoryStream msDecrypt = new MemoryStream(Convert.FromBase64String(cipherText)))
            {
                using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
                {
                    using (StreamReader srDecrypt = new StreamReader(csDecrypt))
                    {
                        plaintext = srDecrypt.ReadToEnd();
                    }
                }
            }
        }

        return plaintext;
    }
}

// 示例用法
class Program
{
    static void Main()
    {
        string key = "your_secret_key_123"; // 密钥长度必须为32个字符
        string original = "Here is some data to encrypt!";

        string encrypted = AesEncryption.Encrypt(original, key);
        Console.WriteLine("Encrypted: " + encrypted);

        string decrypted = AesEncryption.Decrypt(encrypted, key);
        Console.WriteLine("Decrypted: " + decrypted);
    }
}

解释说明：

1. 加密方法 (Encrypt):

   • 使用AES算法进行加密。
   • Key 和 IV（初始化向量）是从提供的密钥中提取的前32个字符和前16个字符。
   • 加密后的数据以Base64编码格式返回。

2. 解密方法 (Decrypt):

   • 使用相同的AES算法和密钥进行解密。
   • 输入是Base64编码的加密字符串，输出是原始的明文。

3. 示例用法:

   • 创建一个密钥，并对一段文本进行加密和解密操作。
   • 打印加密后的字符串和解密后的结果。