websitepanel/WebsitePanel/Sources/WebsitePanel.WebDavPortal/Cryptography/CryptoUtils.cs
2014-12-30 03:41:58 -08:00

198 lines
No EOL
7 KiB
C#

using Microsoft.Win32;
using System;
using System.Collections.Generic;
using System.Configuration;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Web;
namespace WebsitePanel.WebDavPortal.Cryptography
{
public class CryptoUtils : ICryptography
{
private string EnterpriseServerRegistryPath = "SOFTWARE\\WebsitePanel\\EnterpriseServer";
private string CryptoKey
{
get
{
string Key = ConfigurationManager.AppSettings["WebsitePanel.AltCryptoKey"];
string value = string.Empty;
if (!string.IsNullOrEmpty(Key))
{
RegistryKey root = Registry.LocalMachine;
RegistryKey rk = root.OpenSubKey(EnterpriseServerRegistryPath);
if (rk != null)
{
value = (string)rk.GetValue(Key, null);
rk.Close();
}
}
if (!string.IsNullOrEmpty(value))
return value;
else
return ConfigurationManager.AppSettings["WebsitePanel.CryptoKey"];
}
}
private bool EncryptionEnabled
{
get
{
return (ConfigurationManager.AppSettings["WebsitePanel.EncryptionEnabled"] != null)
? Boolean.Parse(ConfigurationManager.AppSettings["WebsitePanel.EncryptionEnabled"]) : true;
}
}
public string Encrypt(string InputText)
{
string Password = CryptoKey;
if (!EncryptionEnabled)
return InputText;
if (InputText == null)
return InputText;
// We are now going to create an instance of the
// Rihndael class.
RijndaelManaged RijndaelCipher = new RijndaelManaged();
// First we need to turn the input strings into a byte array.
byte[] PlainText = System.Text.Encoding.Unicode.GetBytes(InputText);
// We are using salt to make it harder to guess our key
// using a dictionary attack.
byte[] Salt = Encoding.ASCII.GetBytes(Password.Length.ToString());
// The (Secret Key) will be generated from the specified
// password and salt.
PasswordDeriveBytes SecretKey = new PasswordDeriveBytes(Password, Salt);
// Create a encryptor from the existing SecretKey bytes.
// We use 32 bytes for the secret key
// (the default Rijndael key length is 256 bit = 32 bytes) and
// then 16 bytes for the IV (initialization vector),
// (the default Rijndael IV length is 128 bit = 16 bytes)
ICryptoTransform Encryptor = RijndaelCipher.CreateEncryptor(SecretKey.GetBytes(32), SecretKey.GetBytes(16));
// Create a MemoryStream that is going to hold the encrypted bytes
MemoryStream memoryStream = new MemoryStream();
// Create a CryptoStream through which we are going to be processing our data.
// CryptoStreamMode.Write means that we are going to be writing data
// to the stream and the output will be written in the MemoryStream
// we have provided. (always use write mode for encryption)
CryptoStream cryptoStream = new CryptoStream(memoryStream, Encryptor, CryptoStreamMode.Write);
// Start the encryption process.
cryptoStream.Write(PlainText, 0, PlainText.Length);
// Finish encrypting.
cryptoStream.FlushFinalBlock();
// Convert our encrypted data from a memoryStream into a byte array.
byte[] CipherBytes = memoryStream.ToArray();
// Close both streams.
memoryStream.Close();
cryptoStream.Close();
// Convert encrypted data into a base64-encoded string.
// A common mistake would be to use an Encoding class for that.
// It does not work, because not all byte values can be
// represented by characters. We are going to be using Base64 encoding
// That is designed exactly for what we are trying to do.
string EncryptedData = Convert.ToBase64String(CipherBytes);
// Return encrypted string.
return EncryptedData;
}
public string Decrypt(string InputText)
{
try
{
if (!EncryptionEnabled)
return InputText;
if (InputText == null || InputText == "")
return InputText;
string Password = CryptoKey;
RijndaelManaged RijndaelCipher = new RijndaelManaged();
byte[] EncryptedData = Convert.FromBase64String(InputText);
byte[] Salt = Encoding.ASCII.GetBytes(Password.Length.ToString());
PasswordDeriveBytes SecretKey = new PasswordDeriveBytes(Password, Salt);
// Create a decryptor from the existing SecretKey bytes.
ICryptoTransform Decryptor = RijndaelCipher.CreateDecryptor(SecretKey.GetBytes(32), SecretKey.GetBytes(16));
MemoryStream memoryStream = new MemoryStream(EncryptedData);
// Create a CryptoStream. (always use Read mode for decryption).
CryptoStream cryptoStream = new CryptoStream(memoryStream, Decryptor, CryptoStreamMode.Read);
// Since at this point we don't know what the size of decrypted data
// will be, allocate the buffer long enough to hold EncryptedData;
// DecryptedData is never longer than EncryptedData.
byte[] PlainText = new byte[EncryptedData.Length];
// Start decrypting.
int DecryptedCount = cryptoStream.Read(PlainText, 0, PlainText.Length);
memoryStream.Close();
cryptoStream.Close();
// Convert decrypted data into a string.
string DecryptedData = Encoding.Unicode.GetString(PlainText, 0, DecryptedCount);
// Return decrypted string.
return DecryptedData;
}
catch
{
return "";
}
}
private string SHA1(string plainText)
{
// Convert plain text into a byte array.
byte[] plainTextBytes = Encoding.UTF8.GetBytes(plainText);
HashAlgorithm hash = new SHA1Managed(); ;
// Compute hash value of our plain text with appended salt.
byte[] hashBytes = hash.ComputeHash(plainTextBytes);
// Return the result.
return Convert.ToBase64String(hashBytes);
}
}
}