C# 字符串加密解密类

/// <summary>
/// 字符串加密解密类
/// </summary>
public static class StringSecurity
{
    /// <summary>
    /// DES加密
    /// </summary>
    /// <param name="input"></param>
    /// <param name="keystr"></param>
    /// <param name="ivstr"></param>
    /// <param name="encod"></param>
    /// <returns></returns>
    public static string DESEncrypt(string input, string keystr, string ivstr, Encoding encod)
    {
        MemoryStream? ms = null;
        CryptoStream? cs = null;
        StreamWriter? sw = null;
        DES des = DES.Create();
        try
        {
            byte[] key = Encoding.UTF8.GetBytes(keystr);
            byte[] iv = Encoding.UTF8.GetBytes(ivstr);
            ms = new MemoryStream();
            cs = new CryptoStream(ms, des.CreateEncryptor(key, iv), CryptoStreamMode.Write);
            sw = new StreamWriter(cs, encod);
            sw.Write(input);
            sw.Flush();
            cs.FlushFinalBlock();
            return Convert.ToBase64String(ms.GetBuffer(), 0, (int)ms.Length);
        }
        finally
        {
            sw?.Close();
            cs?.Close();
            ms?.Close();
        }
    }
    /// <summary>
    /// DES解密
    /// </summary>
    /// <param name="input"></param>
    /// <param name="keystr"></param>
    /// <param name="ivstr"></param>
    /// <param name="encod"></param>
    /// <returns></returns>
    public static string DESDecrypt(string input, string keystr, string ivstr, Encoding encod)
    {
        MemoryStream? ms = null;
        CryptoStream? cs = null;
        StreamReader? sr = null;
        DES des = DES.Create();
        try
        {
            byte[] key = Encoding.UTF8.GetBytes(keystr);
            byte[] iv = Encoding.UTF8.GetBytes(ivstr);
            ms = new MemoryStream(Convert.FromBase64String(input));
            cs = new CryptoStream(ms, des.CreateDecryptor(key, iv), CryptoStreamMode.Read);
            sr = new StreamReader(cs, encod);
            return sr.ReadToEnd();
        }
        finally
        {
            sr?.Close();
            cs?.Close();
            ms?.Close();
        }
    }
    /// <summary>
    /// SHA1加密
    /// </summary>
    /// <param name="input"></param>
    /// <param name="encod"></param>
    /// <returns></returns>
    public static string SHA1Encrypt(string input, Encoding encod)
    {
        SHA1 sha1 = SHA1.Create();
        byte[] encryptedBytes = sha1.ComputeHash(encod.GetBytes(input));
        StringBuilder sb = new();
        for (int i = 0; i < encryptedBytes.Length; i++)
        {
            sb.AppendFormat("{0:x2}", encryptedBytes[i]);
        }
        return sb.ToString();
    }
    /// <summary>
    /// MD5加密（32位）
    /// </summary>
    /// <param name="input"></param>
    /// <param name="encod"></param>
    /// <returns></returns>
    public static string MD5Encrypt(string input, Encoding encod)
    {
        MD5 md5 = MD5.Create();
        byte[] source = md5.ComputeHash(encod.GetBytes(input));
        StringBuilder sb = new();
        for (int i = 0; i < source.Length; i++)
        {
            sb.Append(source[i].ToString("X"));//x小写 X大写 x2填充对齐
        }
        return sb.ToString();
    }
    /// <summary>
    /// Base64加密
    /// </summary>
    /// <param name="input"></param>
    /// <param name="encod"></param>
    /// <returns></returns>
    public static string Base64Encrypt(string input, Encoding encod)
    {
        return Convert.ToBase64String(encod.GetBytes(input));
    }
    /// <summary>
    /// Base64解密
    /// </summary>
    /// <param name="input"></param>
    /// <param name="encod"></param>
    /// <returns></returns>
    public static string Base64Decrypt(string input, Encoding encod)
    {
        return encod.GetString(Convert.FromBase64String(input));
    }
}