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

namespace MySystem
{
    public class CryptHelper
    {
        /// <summary>
        /// aes加密
        /// </summary>
        /// <param name="str">加密字符串</param>
        /// <param name="key">密钥</param>
        /// <param name="iv">向量</param>
        /// <param name="mode">加密模式</param>
        /// <param name="padding">填充模式</param>
        /// <returns>加密后字符串</returns>
        public static string AesEncrypt(string str, string key, string iv, string mode = "CBC", string padding = "PKCS7")
        {
            if (string.IsNullOrEmpty(str)) return null;
            Byte[] toEncryptArray = Encoding.UTF8.GetBytes(str);

            CipherMode cipherMode = CipherMode.CBC;
            PaddingMode paddingMode = PaddingMode.PKCS7;
            if(mode == "CBC") cipherMode = CipherMode.CBC;
            if(mode == "ECB") cipherMode = CipherMode.ECB;
            if(mode == "CFB") cipherMode = CipherMode.CFB;
            if(mode == "CTS") cipherMode = CipherMode.CTS;
            if(padding == "PKCS7") paddingMode = PaddingMode.PKCS7;
            if(padding == "None") paddingMode = PaddingMode.None;
            if(padding == "Zeros") paddingMode = PaddingMode.Zeros;
            if(padding == "ISO10126") paddingMode = PaddingMode.ISO10126;
            if(padding == "ANSIX923") paddingMode = PaddingMode.ANSIX923;

            System.Security.Cryptography.RijndaelManaged rm = new System.Security.Cryptography.RijndaelManaged
            {
                Key = Encoding.UTF8.GetBytes(key),
                IV = Encoding.UTF8.GetBytes(iv),
                Mode = cipherMode,
                Padding = paddingMode
            };
            System.Security.Cryptography.ICryptoTransform cTransform = rm.CreateEncryptor();
            Byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);
            string jsonData = Convert.ToBase64String(resultArray, 0, resultArray.Length);
            return Convert.ToBase64String(Encoding.UTF8.GetBytes(jsonData));
        }
    
    }
}