c# 数字ID与可见字符串码互转的一种实现
适用场景:有时用户id等之类的字段用的是int类型,但在有些时候不想让这个id暴露,于是可以考虑把这个id转换成一个字符串,而且要可根据这个字符串得到相应的id值
实现如下代码:
using System;
using System.Data;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
namespace My.Common
{
/// <summary>
/// 用户公共类
/// </summary>
public static class User
{
/// <summary>
/// 加密对象
/// </summary>
private static readonly ICryptoTransform Encryptor;
/// <summary>
/// 解密对象
/// </summary>
private static readonly ICryptoTransform Decryptor;
static User()
{
#region 加密解密初始化
//此处key要改成自己的
const string key = "TEST2CDCA1CAEA1234D84FBDE3TEST22";
var cryp = new TripleDESCryptoServiceProvider
{
Key = Encoding.ASCII.GetBytes(key.Substring(0, 24)),
IV = Encoding.ASCII.GetBytes(key.Substring(24, 8)),
Mode = CipherMode.ECB,
Padding = PaddingMode.PKCS7
};
Encryptor = cryp.CreateEncryptor();
Decryptor = cryp.CreateDecryptor();
#endregion
}
}
/// <summary>
/// 获取用户CODE
/// </summary>
/// <returns></returns>
public static string GetUserCodeV2(int userId)
{
var data = BitConverter.GetBytes(userId); //4个字节
data = Encryptor.TransformFinalBlock(data, 0, data.Length);//加密后8个字节
var bs = new byte[9];//避免BASE64后最后一位会为=
bs[0] = (byte)(userId % 256);//生成一个字节 补满9个字节
data.CopyTo(bs, 1);
var strBase1 = Convert.ToBase64String(bs);
//上面base64出来的字符串中可能会含有 "+" "/",再次base64会没有
return strBase1.Base64Encode();
}
/// <summary>
/// 获取用户ID
/// </summary>
/// <returns></returns>
public static int GetUserIdV2(string code)
{
try
{
var baseCode = code.Base64Decode();
var bs = Convert.FromBase64String(baseCode);
return BitConverter.ToInt32(Decryptor.TransformFinalBlock(bs, 1, bs.Length - 1), 0);
}
catch
{
return 0;
}
}
}
}
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