using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Security.Cryptography;
namespace GoContactSyncMod
{
//class AccountEncryption
internal partial class Encryption
{
private static byte[] GetKey(string email)
{
ASCIIEncoding enc = new ASCIIEncoding();
SHA256 shaM = new SHA256Managed();
return shaM.ComputeHash(enc.GetBytes(email));
}
private static byte[] GetIV(string email)
{
ASCIIEncoding enc = new ASCIIEncoding();
MD5 md5 = MD5.Create();
return md5.ComputeHash(enc.GetBytes(email));
}
public static string DecryptPassword(string email, string encryptedPassword)
{
try
{
RijndaelManaged rijndael = new RijndaelManaged();
rijndael.IV = GetIV(email);
rijndael.Key = GetKey(email);
ICryptoTransform decryptor = rijndael.CreateDecryptor(rijndael.Key, rijndael.IV);
//Now decrypt the previously encrypted password using the decryptor obtained in the above step.
byte[] encrypted = HexEncoding.GetBytes(encryptedPassword);
MemoryStream msDecrypt = new MemoryStream(encrypted);
CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read);
//byte[] fromEncrypt = new byte[encrypted.Length];
byte[] fromEncrypt = ReadFully(csDecrypt);//(
//Read the data out of the crypto stream.
//csDecrypt.Read(fromEncrypt, 0, fromEncrypt.Length);
//csDecrypt.Close();
//msDecrypt.Close();
//Convert the byte array back into a string.
string result = new ASCIIEncoding().GetString(fromEncrypt);
return result;
}
catch (Exception e)
{
throw new PasswordEncryptionException("Error decryption password", e);
}
}
public static string EncryptPassword(string email, string password)
{
RijndaelManaged rijndael = new RijndaelManaged();
rijndael.IV = GetIV(email);
rijndael.Key = GetKey(email);
ICryptoTransform encryptor = rijndael.CreateEncryptor(rijndael.Key, rijndael.IV);
byte[] toEncrypt = new ASCIIEncoding().GetBytes(password);
//Encrypt the data.
MemoryStream msEncrypt = new MemoryStream();
CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write);
//byte[] encrypted = ReadFully(csEncrypt);
/*byte[] codes = new byte[msEncrypt.Capacity];
csEncrypt.Read(codes, 0, codes.Length);
csEncrypt.Close();
msEncrypt.Close();*/
//Write all data to the crypto stream and flush it.
csEncrypt.Write(toEncrypt, 0, toEncrypt.Length);
csEncrypt.FlushFinalBlock();
//Convert the byte array back into a string.
return HexEncoding.ToString(msEncrypt.ToArray());
}
public static byte[] ReadFully(Stream stream)
{
byte[] buffer = new byte[32768];
using (MemoryStream ms = new MemoryStream())
{
while (true)
{
int read = stream.Read(buffer, 0, buffer.Length);
if (read <= 0)
return ms.ToArray();
ms.Write(buffer, 0, read);
}
}
}
}
internal class PasswordEncryptionException : Exception
{
public PasswordEncryptionException() : base() { }
public PasswordEncryptionException(string message) : base(message) { }
public PasswordEncryptionException(string message, Exception innerException) : base(message, innerException) { }
}
/// <summary>
/// Summary description for HexEncoding.
/// </summary>
internal class HexEncoding
{
public HexEncoding()
{
//
// TODO: Add constructor logic here
//
}
public static int GetByteCount(string hexString)
{
int numHexChars = 0;
char c;
// remove all none A-F, 0-9, characters
for (int i = 0; i < hexString.Length; i++)
{
c = hexString[i];
if (IsHexDigit(c))
numHexChars++;
}
// if odd number of characters, discard last character
if (numHexChars % 2 != 0)
{
numHexChars--;
}
return numHexChars / 2; // 2 characters per byte
}
/// <summary>
/// Creates a byte array from the hexadecimal string. Each two characters are combined
/// to create one byte. First two hexadecimal characters become first byte in returned array.
/// Non-hexadecimal characters are ignored.
/// </summary>
/// <param name="hexString">string to convert to byte array</param>
/// <returns>byte array, in the same left-to-right order as the hexString</returns>
public static byte[] GetBytes(string hexString)
{
int discarded;
return GetBytes(hexString, out discarded);
}
/// <summary>
/// Creates a byte array from the hexadecimal string. Each two characters are combined
/// to create one byte. First two hexadecimal characters become first byte in returned array.
/// Non-hexadecimal characters are ignored.
/// </summary>
/// <param name="hexString">string to convert to byte array</param>
/// <param name="discarded">number of characters in string ignored</param>
/// <returns>byte array, in the same left-to-right order as the hexString</returns>
public static byte[] GetBytes(string hexString, out int discarded)
{
discarded = 0;
string newString = "";
char c;
// remove all none A-F, 0-9, characters
for (int i = 0; i < hexString.Length; i++)
{
c = hexString[i];
if (IsHexDigit(c))
newString += c;
else
discarded++;
}
// if odd number of characters, discard last character
if (newString.Length % 2 != 0)
{
discarded++;
newString = newString.Substring(0, newString.Length - 1);
}
int byteLength = newString.Length / 2;
byte[] bytes = new byte[byteLength];
string hex;
int j = 0;
for (int i = 0; i < bytes.Length; i++)
{
hex = new String(new Char[] { newString[j], newString[j + 1] });
bytes[i] = HexToByte(hex);
j = j + 2;
}
return bytes;
}
public static string ToString(byte[] bytes)
{
string hexString = "";
for (int i = 0; i < bytes.Length; i++)
{
hexString += bytes[i].ToString("X2");
}
return hexString;
}
/// <summary>
/// Determines if given string is in proper hexadecimal string format
/// </summary>
/// <param name="hexString"></param>
/// <returns></returns>
public static bool InHexFormat(string hexString)
{
bool hexFormat = true;
foreach (char digit in hexString)
{
if (!IsHexDigit(digit))
{
hexFormat = false;
break;
}
}
return hexFormat;
}
/// <summary>
/// Returns true is c is a hexadecimal digit (A-F, a-f, 0-9)
/// </summary>
/// <param name="c">Character to test</param>
/// <returns>true if hex digit, false if not</returns>
public static bool IsHexDigit(Char c)
{
int numChar;
int numA = Convert.ToInt32('A');
int num1 = Convert.ToInt32('0');
c = Char.ToUpper(c);
numChar = Convert.ToInt32(c);
if (numChar >= numA && numChar < (numA + 6))
return true;
if (numChar >= num1 && numChar < (num1 + 10))
return true;
return false;
}
/// <summary>
/// Converts 1 or 2 character string into equivalant byte value
/// </summary>
/// <param name="hex">1 or 2 character string</param>
/// <returns>byte</returns>
private static byte HexToByte(string hex)
{
if (hex.Length > 2 || hex.Length <= 0)
throw new ArgumentException("hex must be 1 or 2 characters in length");
byte newByte = byte.Parse(hex, System.Globalization.NumberStyles.HexNumber);
return newByte;
}
}
}
