C#实现常见加密算法的示例代码

本篇攻略将会针对C#语言来实现几种常见的加密算法，包括MD5哈希、SHA-1哈希、AES对称加密、RSA非对称加密和Base64编码等。我们将会给出具体的实现代码，并接合实例说明，方便大家在实际开发中使用。

MD5哈希

MD5消息摘要算法常用于数据传输过程中的完整性校验，或者用于保证敏感数据的安全。

示例1：字符串的MD5哈希值

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

class Program {
    static void Main(string[] args) {
        string input = "hello, world!";
        Console.WriteLine("输入字符串：" + input);

        var md5 = MD5.Create();
        byte[] inputBytes = Encoding.ASCII.GetBytes(input);
        byte[] hashBytes = md5.ComputeHash(inputBytes);

        string output = BitConverter.ToString(hashBytes).Replace("-", "").ToLower();
        Console.WriteLine("MD5哈希值：" + output);

        Console.ReadKey();
    }
}

示例2：文件的MD5哈希值

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

class Program {
    static void Main(string[] args) {
        string fileName = "example.txt";
        Console.WriteLine("文件名：" + fileName);

        var md5 = MD5.Create();
        using (var stream = File.OpenRead(fileName)) {
            byte[] hashBytes = md5.ComputeHash(stream);
            string output = BitConverter.ToString(hashBytes).Replace("-", "").ToLower();
            Console.WriteLine("MD5哈希值：" + output);
        }

        Console.ReadKey();
    }
}

SHA-1哈希

SHA-1哈希算法也常用于数据传输过程中的完整性校验，但相对于MD5，它的安全性更高。

示例：字符串的SHA-1哈希值

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

class Program {
    static void Main(string[] args) {
        string input = "hello, world!";
        Console.WriteLine("输入字符串：" + input);

        var sha1 = SHA1.Create();
        byte[] inputBytes = Encoding.ASCII.GetBytes(input);
        byte[] hashBytes = sha1.ComputeHash(inputBytes);

        string output = BitConverter.ToString(hashBytes).Replace("-", "").ToLower();
        Console.WriteLine("SHA-1哈希值：" + output);

        Console.ReadKey();
    }
}

AES对称加密

AES对称加密算法常用于数据的加密和解密过程中，相对于DES，它的安全性更高。

示例：字符串的AES对称加密和解密

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

class AesEncryptor {
    private readonly byte[] key;
    private readonly byte[] iv;

    public AesEncryptor(string key, string iv) {
        this.key = Encoding.ASCII.GetBytes(key);
        this.iv = Encoding.ASCII.GetBytes(iv);
    }

    public byte[] Encrypt(byte[] input) {
        using (var aes = Aes.Create()) {
            aes.Key = key;
            aes.IV = iv;

            var encryptor = aes.CreateEncryptor();
            using (var stream = new MemoryStream()) {
                using (var cryptoStream = new CryptoStream(stream, encryptor, CryptoStreamMode.Write)) {
                    cryptoStream.Write(input, 0, input.Length);
                    cryptoStream.FlushFinalBlock();
                    return stream.ToArray();
                }
            }
        }
    }

    public byte[] Decrypt(byte[] input) {
        using (var aes = Aes.Create()) {
            aes.Key = key;
            aes.IV = iv;

            var decryptor = aes.CreateDecryptor();
            using (var stream = new MemoryStream()) {
                using (var cryptoStream = new CryptoStream(stream, decryptor, CryptoStreamMode.Write)) {
                    cryptoStream.Write(input, 0, input.Length);
                    cryptoStream.FlushFinalBlock();
                    return stream.ToArray();
                }
            }
        }
    }
}

class Program {
    static void Main(string[] args) {
        string input = "hello, world!";
        Console.WriteLine("输入字符串：" + input);

        var encryptor = new AesEncryptor("my_secret_key_123", "my_secret_iv_456");
        byte[] inputBytes = Encoding.UTF8.GetBytes(input);
        byte[] encryptedBytes = encryptor.Encrypt(inputBytes);
        Console.WriteLine("加密结果：" + Convert.ToBase64String(encryptedBytes));

        byte[] decryptedBytes = encryptor.Decrypt(encryptedBytes);
        string output = Encoding.UTF8.GetString(decryptedBytes);
        Console.WriteLine("解密结果：" + output);

        Console.ReadKey();
    }
}

RSA非对称加密

RSA非对称加密算法常用于数字签名和数据的加密和解密过程中，它采用公钥进行加密，采用私钥进行解密。

示例：字符串的RSA非对称加密和解密

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

class RsaEncryptor {
    private readonly RSA rsa;

    public RsaEncryptor(int keyLength) {
        rsa = RSA.Create(keyLength);
    }

    public byte[] Encrypt(byte[] input, RSAParameters publicKey = new RSAParameters()) {
        rsa.ImportParameters(publicKey);
        return rsa.Encrypt(input, RSAEncryptionPadding.Pkcs1);
    }

    public byte[] Decrypt(byte[] input) {
        return rsa.Decrypt(input, RSAEncryptionPadding.Pkcs1);
    }

    public RSAParameters GetPublicKey() {
        return rsa.ExportParameters(false);
    }

    public RSAParameters GetPrivateKey() {
        return rsa.ExportParameters(true);
    }
}

class Program {
    static void Main(string[] args) {
        string input = "hello, world!";
        Console.WriteLine("输入字符串：" + input);

        var encryptor = new RsaEncryptor(2048);
        RSAParameters publicKey = encryptor.GetPublicKey();
        RSAParameters privateKey = encryptor.GetPrivateKey();

        byte[] inputBytes = Encoding.UTF8.GetBytes(input);
        byte[] encryptedBytes = encryptor.Encrypt(inputBytes, publicKey);
        Console.WriteLine("加密结果：" + Convert.ToBase64String(encryptedBytes));

        byte[] decryptedBytes = encryptor.Decrypt(encryptedBytes);
        string output = Encoding.UTF8.GetString(decryptedBytes);
        Console.WriteLine("解密结果：" + output);

        Console.ReadKey();
    }
}

Base64编码

Base64编码算法常用于数据的传输过程中，将二进制数据转换为可打印的ASCII字符串。

示例：字符串的Base64编码和解码

using System;
using System.Text;

class Base64Encoder {
    public string Encode(byte[] input) {
        return Convert.ToBase64String(input);
    }

    public byte[] Decode(string input) {
        return Convert.FromBase64String(input);
    }
}

class Program {
    static void Main(string[] args) {
        string input = "hello, world!";
        Console.WriteLine("输入字符串：" + input);

        var encoder = new Base64Encoder();
        byte[] inputBytes = Encoding.UTF8.GetBytes(input);
        string encodedString = encoder.Encode(inputBytes);
        Console.WriteLine("Base64编码结果：" + encodedString);

        byte[] decodedBytes = encoder.Decode(encodedString);
        string output = Encoding.UTF8.GetString(decodedBytes);
        Console.WriteLine("Base64解码结果：" + output);

        Console.ReadKey();
    }
}

以上就是C#实现常见加密算法的示例代码的完整攻略，希望能够对读者有所帮助。