C is a common string encryption and decryption method to encapsulate code

  • 2020-05-27 06:57:56
  • OfStack


// methods 1
// Must be added to System.Web A reference to the 
//using System.Web.Security;
/// <summary>
/// SHA1 Encrypted string 
/// </summary>
/// <param name="source"> The source string </param>
/// <returns> An encrypted string </returns>
public string SHA1(string source)
{
    return FormsAuthentication.HashPasswordForStoringInConfigFile(source, "SHA1");
}
/// <summary>
/// MD5 Encrypted string 
/// </summary>
/// <param name="source"> The source string </param>
/// <returns> An encrypted string </returns>
public string MD5(string source)
{
    return FormsAuthentication.HashPasswordForStoringInConfigFile(source, "MD5");;
}

// methods 2( Reversible encryption and decryption ) : 
//using System.Security.Cryptography;
public string Encode(string data)
{
    byte[] byKey = System.Text.ASCIIEncoding.ASCII.GetBytes(KEY_64);
    byte[] byIV = System.Text.ASCIIEncoding.ASCII.GetBytes(IV_64);
    DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
    int i = cryptoProvider.KeySize;
    MemoryStream ms = new MemoryStream();
    CryptoStream cst = new CryptoStream(ms, cryptoProvider.CreateEncryptor(byKey, byIV), CryptoStreamMode.Write);
    StreamWriter sw = new StreamWriter(cst);
    sw.Write(data);
    sw.Flush();
    cst.FlushFinalBlock();
    sw.Flush();
    return Convert.ToBase64String(ms.GetBuffer(), 0, (int)ms.Length);
}
public string Decode(string data)
{
    byte[] byKey = System.Text.ASCIIEncoding.ASCII.GetBytes(KEY_64);
    byte[] byIV = System.Text.ASCIIEncoding.ASCII.GetBytes(IV_64);
    byte[] byEnc;
    try
    {
        byEnc = Convert.FromBase64String(data);
    }
    catch
    {
        return null;
    }
    DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
    MemoryStream ms = new MemoryStream(byEnc);
    CryptoStream cst = new CryptoStream(ms, cryptoProvider.CreateDecryptor(byKey, byIV), CryptoStreamMode.Read);
    StreamReader sr = new StreamReader(cst);

// methods 3(MD5 The irreversible ) : 
//using System.Security.Cryptography;
//MD5 Irreversible encryption 
//32 An encryption 
public string GetMD5_32(string s, string _input_charset)
{
    MD5 md5 = new MD5CryptoServiceProvider();
    byte[] t = md5.ComputeHash(Encoding.GetEncoding(_input_charset).GetBytes(s));
    StringBuilder sb = new StringBuilder(32);
    for (int i = 0; i < t.Length; i++)
    {
        sb.Append(t[i].ToString("x").PadLeft(2, '0'));
    }
    return sb.ToString();
}
//16 An encryption 
public static string GetMd5_16(string ConvertString)
{
    MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
    string t2 = BitConverter.ToString(md5.ComputeHash(UTF8Encoding.Default.GetBytes(ConvertString)), 4, 8);
    t2 = t2.Replace("-", "");
    return t2;
}

// methods 4( Symmetric encryption ) : 
//using System.IO;
//using System.Security.Cryptography;
private SymmetricAlgorithm mobjCryptoService;
private string Key;
/// <summary>   
///  The constructor of the symmetric encryption class    
/// </summary>   
public SymmetricMethod()
{
    mobjCryptoService = new RijndaelManaged();
    Key = "Guz(%&hj7x89H$yuBI0456FtmaT5&fvHUFCy76*h%(HilJ$lhj!y6&(*jkP87jH7";
}
/// <summary>   
///  Get the key    
/// </summary>   
/// <returns> The key </returns>   
private byte[] GetLegalKey()
{
    string sTemp = Key;
    mobjCryptoService.GenerateKey();
    byte[] bytTemp = mobjCryptoService.Key;
    int KeyLength = bytTemp.Length;
    if (sTemp.Length > KeyLength)
        sTemp = sTemp.Substring(0, KeyLength);
    else if (sTemp.Length < KeyLength)
        sTemp = sTemp.PadRight(KeyLength, ' ');
    return ASCIIEncoding.ASCII.GetBytes(sTemp);
}
/// <summary>   
///  Get the initial vector IV   
/// </summary>   
/// <returns> Try a vector IV</returns>   
private byte[] GetLegalIV()
{
    string sTemp = "E4ghj*Ghg7!rNIfb&95GUY86GfghUb#er57HBh(u%g6HJ($jhWk7&!hg4ui%$hjk";
    mobjCryptoService.GenerateIV();
    byte[] bytTemp = mobjCryptoService.IV;
    int IVLength = bytTemp.Length;
    if (sTemp.Length > IVLength)
        sTemp = sTemp.Substring(0, IVLength);
    else if (sTemp.Length < IVLength)
        sTemp = sTemp.PadRight(IVLength, ' ');
    return ASCIIEncoding.ASCII.GetBytes(sTemp);
}
/// <summary>   
///  Encryption methods    
/// </summary>   
/// <param name="Source"> The string to be encrypted </param>   
/// <returns> An encrypted string </returns>   
public string Encrypto(string Source)
{
    byte[] bytIn = UTF8Encoding.UTF8.GetBytes(Source);
    MemoryStream ms = new MemoryStream();
    mobjCryptoService.Key = GetLegalKey();
    mobjCryptoService.IV = GetLegalIV();
    ICryptoTransform encrypto = mobjCryptoService.CreateEncryptor();
    CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Write);
    cs.Write(bytIn, 0, bytIn.Length);
    cs.FlushFinalBlock();
    ms.Close();
    byte[] bytOut = ms.ToArray();
    return Convert.ToBase64String(bytOut);
}
/// <summary>   
///  Decryption method    
/// </summary>   
/// <param name="Source"> String to be decrypted </param>   
/// <returns> Decrypted string </returns>   
public string Decrypto(string Source)
{
    byte[] bytIn = Convert.FromBase64String(Source);
    MemoryStream ms = new MemoryStream(bytIn, 0, bytIn.Length);
    mobjCryptoService.Key = GetLegalKey();
    mobjCryptoService.IV = GetLegalIV();
    ICryptoTransform encrypto = mobjCryptoService.CreateDecryptor();
    CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Read);
    StreamReader sr = new StreamReader(cs);
    return sr.ReadToEnd();
}
// methods 5 : 
//using System.IO;
//using System.Security.Cryptography;
//using System.Text;
// Default key vector 
private static byte[] Keys = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
/**//**//**//// <summary>
/// DES Encrypted string  keleyi.com
/// </summary>
/// <param name="encryptString"> A string to be encrypted </param>
/// <param name="encryptKey"> Encryption key , Requirements for 8 position </param>
/// <returns> Encrypting successfully returns the encrypted string, failing to return the source string </returns>
public static string EncryptDES(string encryptString, string encryptKey)
{
    try
    {
        byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));
        byte[] rgbIV = Keys;
        byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
        DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();
        MemoryStream mStream = new MemoryStream();
        CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
        cStream.Write(inputByteArray, 0, inputByteArray.Length);
        cStream.FlushFinalBlock();
        return Convert.ToBase64String(mStream.ToArray());
    }
    catch
    {
        return encryptString;
    }
}
/**//**//**//// <summary>
/// DES Decrypt string  keleyi.com
/// </summary>
/// <param name="decryptString"> A string to be decrypted </param>
/// <param name="decryptKey"> The decryption key , Requirements for 8 position , Same as the encryption key </param>
/// <returns> Decryption successfully returns the decrypted string, failed to return the source string </returns>
public static string DecryptDES(string decryptString, string decryptKey)
{
    try
    {
        byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey);
        byte[] rgbIV = Keys;
        byte[] inputByteArray = Convert.FromBase64String(decryptString);
        DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();
        MemoryStream mStream = new MemoryStream();
        CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
        cStream.Write(inputByteArray, 0, inputByteArray.Length);
        cStream.FlushFinalBlock();
        return Encoding.UTF8.GetString(mStream.ToArray());
    }
    catch
    {
        return decryptString;
    }
} 

// methods 6( File encryption ) : 
//using System.IO;
//using System.Security.Cryptography;
//using System.Text;
// Encrypted file 
private static void EncryptData(String inName, String outName, byte[] desKey, byte[] desIV)
{
    //Create the file streams to handle the input and output files.
    FileStream fin = new FileStream(inName, FileMode.Open, FileAccess.Read);
    FileStream fout = new FileStream(outName, FileMode.OpenOrCreate, FileAccess.Write);
    fout.SetLength(0);
    //Create variables to help with read and write.
    byte[] bin = new byte[100]; //This is intermediate storage for the encryption.
    long rdlen = 0;              //This is the total number of bytes written.
    long totlen = fin.Length;    //This is the total length of the input file.
    int len;                     //This is the number of bytes to be written at a time.
    DES des = new DESCryptoServiceProvider();
    CryptoStream encStream = new CryptoStream(fout, des.CreateEncryptor(desKey, desIV), CryptoStreamMode.Write);
    //Read from the input file, then encrypt and write to the output file.
    while (rdlen < totlen)
    {
        len = fin.Read(bin, 0, 100);
        encStream.Write(bin, 0, len);
        rdlen = rdlen + len;
    }
    encStream.Close();
    fout.Close();
    fin.Close();
}
// Declassified documents 
private static void DecryptData(String inName, String outName, byte[] desKey, byte[] desIV)
{
    //Create the file streams to handle the input and output files.
    FileStream fin = new FileStream(inName, FileMode.Open, FileAccess.Read);
    FileStream fout = new FileStream(outName, FileMode.OpenOrCreate, FileAccess.Write);
    fout.SetLength(0);
    //Create variables to help with read and write.
    byte[] bin = new byte[100]; //This is intermediate storage for the encryption.
    long rdlen = 0;              //This is the total number of bytes written.
    long totlen = fin.Length;    //This is the total length of the input file.
    int len;                     //This is the number of bytes to be written at a time.
    DES des = new DESCryptoServiceProvider();
    CryptoStream encStream = new CryptoStream(fout, des.CreateDecryptor(desKey, desIV), CryptoStreamMode.Write);
    //Read from the input file, then encrypt and write to the output file.
    while (rdlen < totlen)
    {
        len = fin.Read(bin, 0, 100);
        encStream.Write(bin, 0, len);
        rdlen = rdlen + len;
    }
    encStream.Close();
    fout.Close();
    fin.Close();
    return sr.ReadToEnd();
}


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