C#编程之AES加密（三）

这一章我们将上一章的内容做进一步完善，由用户输入需要加密的序列号，进行加密：

因为我们输入的都是以字符的形式读取，所以第一步要将读取到的字符存入到数组中： char[] inputBuf = str.ToCharArray(); 

之后对这个数组进行转换成16进制，例如输入A5两个字符，我们要将其转成16进制数，即为0xA5，并将其装入byte数组内。

                            if (inputBuf[j] >= '0' && '9' >= inputBuf[j]) outBuf[i] = (byte)(inputBuf[j++] - '0');
                            else if (('f' >= inputBuf[j]) && (inputBuf[j] >= 'a')) outBuf[i] = (byte)(inputBuf[j++] - 0x57);
                            else if (('F' >= inputBuf[j]) && (inputBuf[j] >= 'A')) outBuf[i] = (byte)(inputBuf[j++] - 0x37);
                            else throw new Exception("ERROR: Format incorrect.");
                            outBuf[i] <<= 4;
                            if (inputBuf[j] >= '0' && '9' >= inputBuf[j]) outBuf[i] |= (byte)(inputBuf[j++] - '0');
                            else if (('f' >= inputBuf[j]) && (inputBuf[j] >= 'a')) outBuf[i] |= (byte)(inputBuf[j++] - 0x57);
                            else if (('F' >= inputBuf[j]) && (inputBuf[j] >= 'A')) outBuf[i] |= (byte)(inputBuf[j++] - 0x37);
                            else throw new Exception("ERROR: Format incorrect.");

最后有我们内部定义的秘钥对这个byte数组元素进行加密，完成我们的加密算法：

                        aes.IV = new byte[16];
                        aes.Key = new byte[] { 0x1F, 0x54, 0x52, 0x6A, 0x73, 0x93, 0x58, 0x9E, 0x4B, 0xCF, 0xFB, 0xAE, 0xFC, 0x97, 0x59, 0x3E };
                        //aes.Mode = CipherMode.CBC;
                        aes.Padding = PaddingMode.None;
                        var cryptoTransform = aes.CreateEncryptor();
                        byte[] resultBuff = cryptoTransform.TransformFinalBlock(outBuf, 0, outBuf.Length);

为了美观，我们可以对字体进行颜色修改： Console.ForegroundColor = ConsoleColor.yourColorCode; 

完整代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Security.Cryptography;

namespace aesDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("========================================================================");
            Console.WriteLine(" Copyright:   GALAXY .ltd in China");
            Console.WriteLine(" Designed by: Milo lu");
            Console.WriteLine(" Date:        Des 05  2019");
            Console.WriteLine(" Version:     12052019");
            Console.WriteLine("e.g.");
            Console.WriteLine(" enter:FD5D9BE05cdb8376a1861896fd5d9be0");
            Console.WriteLine(" print: 05F14C987E2E65FC6AB5A41CA7B5429D");
            Console.WriteLine("=========================================================================");
            int color = 2;
            while (true)
            {
                try
                {
                    using (var aes = new RijndaelManaged())
                    {
                        Console.ForegroundColor = (System.ConsoleColor)color++;
                        if (color >= 16) color = 2;
                        Console.WriteLine("-------------------------------------------");
                        Console.WriteLine("Enter 16 hex:");
                        string str = Console.ReadLine();

                        if(str.Length!=32)
                        {
                            if (str == "exit" || str == "EXIT") 
                            {
                                break;
                            }
                            throw new Exception("ERROR: Enter 16 hex.");
                        }
                        char[] inputBuf = str.ToCharArray();
                        byte[] outBuf=new byte[16];
                        for (int i = 0, j = 0; i < 16; i++)
                        {
                            if (inputBuf[j] >= '0' && '9' >= inputBuf[j]) outBuf[i] = (byte)(inputBuf[j++] - '0');
                            else if (('f' >= inputBuf[j]) && (inputBuf[j] >= 'a')) outBuf[i] = (byte)(inputBuf[j++] - 0x57);
                            else if (('F' >= inputBuf[j]) && (inputBuf[j] >= 'A')) outBuf[i] = (byte)(inputBuf[j++] - 0x37);
                            else throw new Exception("ERROR: Format incorrect.");
                            outBuf[i] <<= 4;
                            if (inputBuf[j] >= '0' && '9' >= inputBuf[j]) outBuf[i] |= (byte)(inputBuf[j++] - '0');
                            else if (('f' >= inputBuf[j]) && (inputBuf[j] >= 'a')) outBuf[i] |= (byte)(inputBuf[j++] - 0x57);
                            else if (('F' >= inputBuf[j]) && (inputBuf[j] >= 'A')) outBuf[i] |= (byte)(inputBuf[j++] - 0x37);
                            else throw new Exception("ERROR: Format incorrect.");
                        }
                        /// aes cryption
                        aes.IV = new byte[16];
                        aes.Key = new byte[] { 0x1F, 0x54, 0x52, 0x6A, 0x73, 0x93, 0x58, 0x9E, 0x4B, 0xCF, 0xFB, 0xAE, 0xFC, 0x97, 0x59, 0x3E };
                        //aes.Mode = CipherMode.CBC;
                        aes.Padding = PaddingMode.None;
                        var cryptoTransform = aes.CreateEncryptor();
                        byte[] resultBuff = cryptoTransform.TransformFinalBlock(outBuf, 0, outBuf.Length);
                        Console.WriteLine("Encoding: ");
                        foreach (byte i in resultBuff)
                            Console.Write("{0:X2}", i);
                        Console.WriteLine();
                        Console.WriteLine("Decoding:");
                        cryptoTransform = aes.CreateDecryptor();
                        resultBuff = cryptoTransform.TransformFinalBlock(resultBuff, 0, resultBuff.Length);
                        foreach (byte i in resultBuff)
                            Console.Write("{0:X2}", i);
                        Console.WriteLine();
                    }
                }
                catch (Exception ex)
                {
                    Console.WriteLine(ex.Message);
                }
            }
        }
    }
}

编译运行:

至此，我们已经基本掌握了AES加密算法。从下一章开始，我们将开始着手设计由接收有外设备通过串口发送过来的序列号，并对这些序列号进行加密，最后再通过串口发送给外设备。

End.

谢谢.