C# AES 加密（开发者如何使用）

C# 中 AES 的工作原理

C# 中的 AES 加密算法是 System.Security.Cryptography 命名空间的一部分。 此命名空间包括 AES 类，允许我们创建 AES 实例，指定密钥大小、密码模式和填充模式，然后使用秘密密钥加密和解密数据。

要在 C# 中使用 AES，请遵循以下基本步骤：

1. 使用 Aes.Create() 创建 AES 类的实例。
2. 设置密钥、IV 和其他相关参数，如密码模式。
3. 使用 ICryptoTransform 接口加密数据并将其写入 MemoryStream。
4. 使用相同的密钥和 IV 解密数据。

我们来创建一个基本的加密和解密 C# 程序。

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

class Program
{
    // Declare a static byte array for encrypted data
    public static byte[] encryptedData;

    // Main method to demonstrate encryption and decryption
    public static void Main(string[] args)
    {
        // String plaintext to be encrypted
        string plaintext = "This is some sensitive data!";
        string key = "abcdefghijklmnop"; // 128-bit key (16 characters)

        // Encrypt the plaintext
        string ciphertext = Encrypt(plaintext, key);
        Console.WriteLine("Encrypted Data: " + ciphertext);

        // Decrypt the ciphertext
        string decryptedData = Decrypt(ciphertext, key);
        Console.WriteLine("Decrypted Data: " + decryptedData);
    }

    // Method to encrypt data
    public static string Encrypt(string plaintext, string key)
    {
        // Create a new instance of the AES encryption algorithm
        using (Aes aes = Aes.Create())
        {
            aes.Key = Encoding.UTF8.GetBytes(key);
            aes.IV = new byte[16]; // Initialization vector (IV)

            // Create an encryptor to perform the stream transform
            ICryptoTransform encryptor = aes.CreateEncryptor(aes.Key, aes.IV);

            // Create the streams used for encryption
            using (MemoryStream ms = new MemoryStream())
            {
                // Create a CryptoStream using the encryptor
                using (CryptoStream cs = new CryptoStream(ms, encryptor, CryptoStreamMode.Write))
                {
                    using (StreamWriter sw = new StreamWriter(cs))
                    {
                        sw.Write(plaintext);
                    }
                }
                // Store the encrypted data in the public static byte array
                encryptedData = ms.ToArray();
                return Convert.ToBase64String(encryptedData);
            }
        }
    }

    // Method to decrypt data
    public static string Decrypt(string ciphertext, string key)
    {
        using (Aes aes = Aes.Create())
        {
            aes.Key = Encoding.UTF8.GetBytes(key);
            aes.IV = new byte[16]; // Initialization vector (IV)

            // Create a decryptor to perform the stream transform
            ICryptoTransform decryptor = aes.CreateDecryptor(aes.Key, aes.IV);

            // Create the streams used for decryption
            using (MemoryStream ms = new MemoryStream(Convert.FromBase64String(ciphertext)))
            {
                using (CryptoStream cs = new CryptoStream(ms, decryptor, CryptoStreamMode.Read))
                {
                    using (StreamReader sr = new StreamReader(cs))
                    {
                        return sr.ReadToEnd();
                    }
                }
            }
        }
    }
}

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

class Program
{
    // Declare a static byte array for encrypted data
    public static byte[] encryptedData;

    // Main method to demonstrate encryption and decryption
    public static void Main(string[] args)
    {
        // String plaintext to be encrypted
        string plaintext = "This is some sensitive data!";
        string key = "abcdefghijklmnop"; // 128-bit key (16 characters)

        // Encrypt the plaintext
        string ciphertext = Encrypt(plaintext, key);
        Console.WriteLine("Encrypted Data: " + ciphertext);

        // Decrypt the ciphertext
        string decryptedData = Decrypt(ciphertext, key);
        Console.WriteLine("Decrypted Data: " + decryptedData);
    }

    // Method to encrypt data
    public static string Encrypt(string plaintext, string key)
    {
        // Create a new instance of the AES encryption algorithm
        using (Aes aes = Aes.Create())
        {
            aes.Key = Encoding.UTF8.GetBytes(key);
            aes.IV = new byte[16]; // Initialization vector (IV)

            // Create an encryptor to perform the stream transform
            ICryptoTransform encryptor = aes.CreateEncryptor(aes.Key, aes.IV);

            // Create the streams used for encryption
            using (MemoryStream ms = new MemoryStream())
            {
                // Create a CryptoStream using the encryptor
                using (CryptoStream cs = new CryptoStream(ms, encryptor, CryptoStreamMode.Write))
                {
                    using (StreamWriter sw = new StreamWriter(cs))
                    {
                        sw.Write(plaintext);
                    }
                }
                // Store the encrypted data in the public static byte array
                encryptedData = ms.ToArray();
                return Convert.ToBase64String(encryptedData);
            }
        }
    }

    // Method to decrypt data
    public static string Decrypt(string ciphertext, string key)
    {
        using (Aes aes = Aes.Create())
        {
            aes.Key = Encoding.UTF8.GetBytes(key);
            aes.IV = new byte[16]; // Initialization vector (IV)

            // Create a decryptor to perform the stream transform
            ICryptoTransform decryptor = aes.CreateDecryptor(aes.Key, aes.IV);

            // Create the streams used for decryption
            using (MemoryStream ms = new MemoryStream(Convert.FromBase64String(ciphertext)))
            {
                using (CryptoStream cs = new CryptoStream(ms, decryptor, CryptoStreamMode.Read))
                {
                    using (StreamReader sr = new StreamReader(cs))
                    {
                        return sr.ReadToEnd();
                    }
                }
            }
        }
    }
}

代码解释

1. Aes.Create() ：这将创建一个新的 AES 加密算法实例。
2. aes.Key ：用于加密和解密的密钥。 它必须是有效大小，如 128 位（16 字节）、192 位或 256 位。
3. aes.IV ：初始化向量（IV）用于随机化加密过程。 在此示例中，我们使用全零 IV 以简化。
4. MemoryStream：这使我们能够以字节流的形式处理加密数据。
5. CryptoStream：它转换数据流（加密或解密）。

将 IronPDF 与 AES 加密集成

var htmlContent = "<h1>Confidential</h1><p>This is sensitive data.</p>";
var renderer = new ChromePdfRenderer();
var pdf = renderer.RenderHtmlAsPdf(htmlContent);
pdf.SaveAs(@"C:\Reports\ConfidentialReport.pdf");

var htmlContent = "<h1>Confidential</h1><p>This is sensitive data.</p>";
var renderer = new ChromePdfRenderer();
var pdf = renderer.RenderHtmlAsPdf(htmlContent);
pdf.SaveAs(@"C:\Reports\ConfidentialReport.pdf");

byte[] pdfBytes = File.ReadAllBytes(@"C:\Reports\ConfidentialReport.pdf");
using (Aes aes = Aes.Create())
{
    aes.Key = Encoding.UTF8.GetBytes("abcdefghijklmnop");
    aes.IV = new byte[16];
    using (var encryptor = aes.CreateEncryptor(aes.Key, aes.IV))
    using (var ms = new MemoryStream())
    {
        using (var cs = new CryptoStream(ms, encryptor, CryptoStreamMode.Write))
        {
            cs.Write(pdfBytes, 0, pdfBytes.Length);
        }
        File.WriteAllBytes(@"C:\Reports\ConfidentialReport.encrypted", ms.ToArray());
    }
}

byte[] pdfBytes = File.ReadAllBytes(@"C:\Reports\ConfidentialReport.pdf");
using (Aes aes = Aes.Create())
{
    aes.Key = Encoding.UTF8.GetBytes("abcdefghijklmnop");
    aes.IV = new byte[16];
    using (var encryptor = aes.CreateEncryptor(aes.Key, aes.IV))
    using (var ms = new MemoryStream())
    {
        using (var cs = new CryptoStream(ms, encryptor, CryptoStreamMode.Write))
        {
            cs.Write(pdfBytes, 0, pdfBytes.Length);
        }
        File.WriteAllBytes(@"C:\Reports\ConfidentialReport.encrypted", ms.ToArray());
    }
}