C#代码实现对AES加密解密

下面是C#代码实现对AES加密解密的完整攻略。

1. 引入所需的命名空间

在C#代码实现对AES加密解密之前，我们需要先引入所需的命名空间。对于AES加密解密，我们需要引入System.Security.Cryptography命名空间。

using System.Security.Cryptography;

2. 生成密钥和向量

在进行AES加密解密之前，我们需要先生成密钥和向量。使用Aes.Create()方法可以创建一个Aes对象，然后可以调用GenerateKey()和GenerateIV()方法生成随机的密钥和向量。

Aes aes = Aes.Create();
aes.GenerateKey();
aes.GenerateIV();
byte[] key = aes.Key;
byte[] iv = aes.IV;

3. 对明文进行加密

对明文进行加密，我们需要先将明文转换为字节数组，然后创建Aes对象，设置密钥和向量，并调用CreateEncryptor()方法创建一个加密器对象，最后使用加密器对象的TransformFinalBlock()方法进行加密。

string text = "Hello, world!";
byte[] plaintext = Encoding.UTF8.GetBytes(text);
Aes aes = Aes.Create();
aes.Key = key;
aes.IV = iv;
ICryptoTransform encryptor = aes.CreateEncryptor();
byte[] ciphertext = encryptor.TransformFinalBlock(plaintext, 0, plaintext.Length);

4. 对密文进行解密

对密文进行解密，我们需要先创建Aes对象，设置密钥和向量，并调用CreateDecryptor()方法创建一个解密器对象，然后使用解密器对象的TransformFinalBlock()方法进行解密，最后将解密后的字节数组转换为字符串。

Aes aes = Aes.Create();
aes.Key = key;
aes.IV = iv;
ICryptoTransform decryptor = aes.CreateDecryptor();
byte[] plaintext = decryptor.TransformFinalBlock(ciphertext, 0, ciphertext.Length);
string text = Encoding.UTF8.GetString(plaintext);

示例1：加密解密字符串

下面是一个加密解密字符串的示例。

string text = "Hello, world!";
byte[] plaintext = Encoding.UTF8.GetBytes(text);

Aes aes = Aes.Create();
aes.GenerateKey();
aes.GenerateIV();
byte[] key = aes.Key;
byte[] iv = aes.IV;

ICryptoTransform encryptor = aes.CreateEncryptor();
byte[] ciphertext = encryptor.TransformFinalBlock(plaintext, 0, plaintext.Length);

ICryptoTransform decryptor = aes.CreateDecryptor();
byte[] decrypted = decryptor.TransformFinalBlock(ciphertext, 0, ciphertext.Length);
string result = Encoding.UTF8.GetString(decrypted);
Console.WriteLine("Original: {0}", text);
Console.WriteLine("Decrypted: {0}", result);

输出结果如下：

Original: Hello, world!
Decrypted: Hello, world!

示例2：加密解密文件

下面是一个加密解密文件的示例。

string plaintextFile = @"D:\plaintext.txt";
string ciphertextFile = @"D:\ciphertext.txt";
string decryptedFile = @"D:\decrypted.txt";

byte[] key;
byte[] iv;
using (Aes aes = Aes.Create())
{
    aes.GenerateKey();
    aes.GenerateIV();
    key = aes.Key;
    iv = aes.IV;

    using (ICryptoTransform encryptor = aes.CreateEncryptor())
    {
        using (FileStream plaintextStream = new FileStream(plaintextFile, FileMode.Open))
        {
            using (FileStream ciphertextStream = new FileStream(ciphertextFile, FileMode.Create))
            {
                using (CryptoStream cryptoStream = new CryptoStream(ciphertextStream, encryptor, CryptoStreamMode.Write))
                {
                    plaintextStream.CopyTo(cryptoStream);
                }
            }
        }
    }

    using (ICryptoTransform decryptor = aes.CreateDecryptor())
    {
        using (FileStream ciphertextStream = new FileStream(ciphertextFile, FileMode.Open))
        {
            using (FileStream decryptedStream = new FileStream(decryptedFile, FileMode.Create))
            {
                using (CryptoStream cryptoStream = new CryptoStream(ciphertextStream, decryptor, CryptoStreamMode.Read))
                {
                    cryptoStream.CopyTo(decryptedStream);
                }
            }
        }
    }
}

string plaintext = File.ReadAllText(plaintextFile);
string decrypted = File.ReadAllText(decryptedFile);
Console.WriteLine("Original: {0}", plaintext);
Console.WriteLine("Decrypted: {0}", decrypted);

这个示例将plaintext.txt文件加密为ciphertext.txt文件，然后将ciphertext.txt文件解密为decrypted.txt文件，并将plaintext.txt和decrypted.txt文件的内容输出。