string str="XXXXXXXXXXXXXX";//需解密数据
//3des密钥
String deskey = "jlgdsgjdgdg";
//3des向量
String desiv = "sfasfsffa";
string result = Decrypt3Des(str,deskey,desiv, System.Security.Cryptography.CipherMode.CBC);//解密结果
#region 3des解密
/// <summary>
???????/// des 解密
???????/// </summary>
???????/// <param name="aStrString">加密的字符串</param>
???????/// <param name="aStrKey">密钥</param>
???????/// <param name="iv">解密矢量：只有在CBC解密模式下才适用</param>
???????/// <param name="mode">运算模式</param> string iv = "12345678"
???????/// <returns>解密的字符串</returns>
???????public string Decrypt3Des(string aStrString, string aStrKey, string iv, CipherMode mode = CipherMode.CBC)
???????{
???????????try
???????????{
???????????????var des = new TripleDESCryptoServiceProvider
???????????????{
???????????????????// ?Key = Encoding.UTF8.GetBytes(aStrKey),
???????????????????//Key =Convert.FromBase64String(aStrKey),
???????????????????Key = Encoding.Default.GetBytes(aStrKey),
???????????????????Mode = mode,
???????????????????Padding = PaddingMode.PKCS7
???????????????};
???????????????if (mode == CipherMode.CBC)
???????????????{
???????????????????des.IV = Encoding.UTF8.GetBytes(iv);
???????????????}
???????????????var desDecrypt = des.CreateDecryptor();
???????????????var result = "";
???????????????byte[] buffer = Convert.FromBase64String(aStrString);
???????????????result = Encoding.UTF8.GetString(desDecrypt.TransformFinalBlock(buffer, 0, buffer.Length));
???????????????return result;
???????????}
???????????catch (Exception e)
???????????{
???????????????return string.Empty;
???????????}
???????}
???????#endregion
.net 3des 解密
原文地址：https://www.cnblogs.com/zttb/p/9210499.html