public bool Decrypt(string MyPrivateKey, string SourcePublicKey)
{
//Decrypt Process
try
{
//Message Signing
RSACryptoServiceProvider rsaCryptoServiceProvider = new RSACryptoServiceProvider(1024);
rsaCryptoServiceProvider.FromXmlString(SourcePublicKey);
SHA1Managed sha1 = new SHA1Managed();
byte[] data = Convert.FromBase64String(msg);
byte[] signature = new byte[128];
byte[] messagebytes = new byte[data.Length - 128];
Array.Copy(data, 0, signature, 0, 128);
Array.Copy(data, 128, messagebytes, 0, messagebytes.Length);
byte[] hash = sha1.ComputeHash(messagebytes);
if (!rsaCryptoServiceProvider.VerifyHash(hash, CryptoConfig.MapNameToOID("SHA1"), signature))
{
//MessageBox.Show("Couldn't verify the message, please verify your certificate.");
return(false);
}
//House-Keeping
int keyLen = BitConverter.ToInt32(messagebytes, 0);
int messageLen = BitConverter.ToInt32(messagebytes, 4);
byte[] keybytes = new byte[keyLen];
byte[] msgbytes = new byte[messageLen];
Array.Copy(messagebytes, 8, keybytes, 0, keyLen);
Array.Copy(messagebytes, 8 + keyLen, msgbytes, 0, messageLen);
//Key Decryption
RSACryptoServiceProvider rsaCryptoServiceProvider2 = new RSACryptoServiceProvider(1024);
rsaCryptoServiceProvider2.FromXmlString(MyPrivateKey);
int base64BlockSize = ((1024 / 8) % 3 != 0) ? (((1024 / 8) / 3) * 4) + 4 : ((1024 / 8) / 3) * 4;
string TempStr = Convert.ToBase64String(keybytes);
int iterations = TempStr.Length / base64BlockSize;
ArrayList arrayList = new ArrayList();
for (int i = 0; i < iterations; i++)
{
byte[] encryptedBytes = Convert.FromBase64String(TempStr.Substring(base64BlockSize * i, base64BlockSize));
Array.Reverse(encryptedBytes);
arrayList.AddRange(rsaCryptoServiceProvider2.Decrypt(encryptedBytes, false));
}
string AES_KEY = Convert.ToBase64String(arrayList.ToArray(Type.GetType("System.Byte")) as byte[]);
//Decrypt AES 128
byte[] DecryptedKey = Convert.FromBase64String(AES_KEY);
SharpPrivacy.Cipher.SymmetricAlgorithm SA = null;
SA = CipherHelper.CreateSymAlgorithm(SymAlgorithms.AES128);
SA.Key = DecryptedKey;
SA.IV = SA.Key;
SharpPrivacy.Cipher.ICryptoTransform Decryptor = SA.CreateDecryptor();
byte[] Result = new byte[msgbytes.Length];
Decryptor.TransformBlock(msgbytes, 0, msgbytes.Length, ref Result, 0);
UnicodeEncoding UE = new UnicodeEncoding();
msg = UnicodeEncoding.ASCII.GetString(Result);
string Temp = Convert.ToBase64String(Result);
string temp2 = UnicodeEncoding.ASCII.GetString(Result);
string temp3 = UnicodeEncoding.Unicode.GetString(Result);
string temp4 = UnicodeEncoding.UTF32.GetString(Result);
string temp5 = UnicodeEncoding.UTF8.GetString(Result);
if (msg.Length > 0)
{
internalType = (InternalMsgTypes)Convert.ToInt32(msg[0].ToString());
int source_Lenght = Convert.ToInt32(msg[1].ToString());
source_name = msg.Substring(2, source_Lenght);
msg = msg.Substring(source_Lenght + 2, msg.Length - source_Lenght - 2);
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
return(false);
}
return(true);
}
public void Encrypt(string MyPrivateKey, string DestinationPublicKey)
{
msg = (int)internalType + source_name.Length.ToString() + source_name + msg;
try
{
//Message Encryption AES 128
SharpPrivacy.Cipher.SymmetricAlgorithm SA = null;
SA = CipherHelper.CreateSymAlgorithm(SymAlgorithms.AES128);
SA.GenerateKey();
SA.IV = SA.Key;
SharpPrivacy.Cipher.ICryptoTransform Encryptor = SA.CreateEncryptor();
UnicodeEncoding UE = new UnicodeEncoding();
byte[] Message = new byte[msg.Length];
for (int i = 0; i < msg.Length; i++)
{
Message[i] = (byte)msg[i];
}
int addedbytes = 0;
int Temp = Message.Length;
while (Temp % 16 != 0)
{
addedbytes++;
Temp++;
}
byte[] NewMessage = new byte[Message.Length + addedbytes];
for (int i = 0; i < NewMessage.Length; i++)
{
if (i < Message.Length)
{
NewMessage[i] = Message[i];
}
else
{
NewMessage[i] = (byte)' ';
}
}
byte[] EncryptedMessage = new byte[NewMessage.Length];
Encryptor.TransformBlock(NewMessage, 0, NewMessage.Length, ref EncryptedMessage, 0);
msg = Convert.ToBase64String(EncryptedMessage);
//Key Encryption
RSACryptoServiceProvider rsaCryptoServiceProvider = new RSACryptoServiceProvider(1024);
rsaCryptoServiceProvider.FromXmlString(DestinationPublicKey);
int keySize = 128;
byte[] bytes = SA.Key;
// The hash function in use by the .NET RSACryptoServiceProvider here is SHA1
// int maxLength = ( keySize ) - 2 - ( 2 * SHA1.Create().ComputeHash( rawBytes ).Length );
int maxLength = keySize - 42;
int dataLength = bytes.Length;
int iterations = dataLength / maxLength;
StringBuilder stringBuilder = new StringBuilder();
for (int i = 0; i <= iterations; i++)
{
byte[] tempBytes = new byte[(dataLength - maxLength * i > maxLength) ? maxLength : dataLength - maxLength * i];
Buffer.BlockCopy(bytes, maxLength * i, tempBytes, 0, tempBytes.Length);
byte[] encryptedBytes = rsaCryptoServiceProvider.Encrypt(tempBytes, false);
// Be aware the RSACryptoServiceProvider reverses the order of encrypted bytes after encryption and before decryption.
// If you do not require compatibility with Microsoft Cryptographic API (CAPI) and/or other vendors.
// Comment out the next line and the corresponding one in the DecryptString function.
Array.Reverse(encryptedBytes);
// Why convert to base 64?
// Because it is the largest power-of-two base printable using only ASCII characters
stringBuilder.Append(Convert.ToBase64String(encryptedBytes));
}
string EncryptedKey = stringBuilder.ToString();
//House-Keeping
byte[] messagebytes = Convert.FromBase64String(msg);
byte[] keybytes = Convert.FromBase64String(EncryptedKey);
byte[] newMsgbytes = new byte[messagebytes.Length + keybytes.Length + 8];
int messageLen = messagebytes.Length;
int keyLen = keybytes.Length;
BitConverter.GetBytes(keyLen).CopyTo(newMsgbytes, 0);
BitConverter.GetBytes(messageLen).CopyTo(newMsgbytes, 4);
keybytes.CopyTo(newMsgbytes, 8);
messagebytes.CopyTo(newMsgbytes, keybytes.Length + 8);
//Message Signing
RSACryptoServiceProvider rsaCryptoServiceProvider2 = new RSACryptoServiceProvider(1024);
rsaCryptoServiceProvider2.FromXmlString(MyPrivateKey);
SHA1Managed sha1 = new SHA1Managed();
byte[] hash = sha1.ComputeHash(newMsgbytes);
byte[] signtature = rsaCryptoServiceProvider2.SignHash(hash, CryptoConfig.MapNameToOID("SHA1"));
byte[] TotalMsg = new byte[newMsgbytes.Length + 128];
Array.Copy(signtature, 0, TotalMsg, 0, 128);
Array.Copy(newMsgbytes, 0, TotalMsg, 128, newMsgbytes.Length);
msg = Convert.ToBase64String(TotalMsg);
}
catch (Exception ex)
{
;
}
}
