/// <summary>
/// Sets CryptoSelect and initializes the stream encryptor and decryptor based on the selected method.
/// </summary>
/// <param name="remoteCryptoBytes">The cryptographic methods supported/wanted by the remote client in CryptoProvide format. The highest order one available will be selected</param>
/// <param name="replace">True if the existing Encryptor/Decryptor object should be replaced with a new instance</param>
protected virtual int SelectCrypto(byte[] remoteCryptoBytes, bool replace)
{
CryptoSelect = new byte[remoteCryptoBytes.Length];
// '2' corresponds to RC4Full
if ((remoteCryptoBytes[3] & 2) == 2 && allowedEncryption.HasFlag(EncryptionTypes.RC4Full))
{
CryptoSelect[3] |= 2;
if (replace)
{
Encryptor = encryptor;
Decryptor = decryptor;
}
return(2);
}
// '1' corresponds to RC4Header
if ((remoteCryptoBytes[3] & 1) == 1 && allowedEncryption.HasFlag(EncryptionTypes.RC4Header))
{
CryptoSelect[3] |= 1;
if (replace)
{
Encryptor = new RC4Header();
Decryptor = new RC4Header();
}
return(1);
}
throw new EncryptionException("No valid encryption method detected");
}
/// <summary>
/// Sets CryptoSelect and initializes the stream encryptor and decryptor based on the selected method.
/// </summary>
/// <param name="remoteCryptoBytes">The cryptographic methods supported/wanted by the remote client in CryptoProvide format. The highest order one available will be selected</param>
/// <param name="replace">True if the existing Encryptor/Decryptor object should be replaced with a new instance</param>
protected virtual int SelectCrypto(byte[] remoteCryptoBytes, bool replace)
{
CryptoSelect = new byte[remoteCryptoBytes.Length];
// '2' corresponds to RC4Full
EncryptionType selectedEncryption;
bool remoteSupportsFull = (remoteCryptoBytes[3] & 2) == 2;
bool remoteSupportsHeader = (remoteCryptoBytes[3] & 1) == 1;
if (EncryptionTypes.PreferredRC4(allowedEncryption) == EncryptionType.RC4Full)
{
if (remoteSupportsFull && allowedEncryption.Contains(EncryptionType.RC4Full))
{
selectedEncryption = EncryptionType.RC4Full;
}
else if (remoteSupportsHeader && allowedEncryption.Contains(EncryptionType.RC4Header))
{
selectedEncryption = EncryptionType.RC4Header;
}
else
{
throw new NotSupportedException("No supported crypto method supported");
}
}
else
{
if (remoteSupportsHeader && allowedEncryption.Contains(EncryptionType.RC4Header))
{
selectedEncryption = EncryptionType.RC4Header;
}
else if (remoteSupportsFull && allowedEncryption.Contains(EncryptionType.RC4Full))
{
selectedEncryption = EncryptionType.RC4Full;
}
else
{
throw new NotSupportedException("No supported crypto method supported");
}
}
if (selectedEncryption == EncryptionType.RC4Full)
{
CryptoSelect[3] |= 2;
if (replace)
{
Encryptor = encryptor;
Decryptor = decryptor;
}
return(2);
}
// '1' corresponds to RC4Header
if (selectedEncryption == EncryptionType.RC4Header)
{
CryptoSelect[3] |= 1;
if (replace)
{
Encryptor = new RC4Header();
Decryptor = new RC4Header();
}
return(1);
}
throw new EncryptionException("No valid encryption method detected");
}
/// <summary>
/// Sets CryptoSelect and initializes the stream encryptor and decryptor based on the selected method.
/// </summary>
/// <param name="remoteCryptoBytes">
/// The cryptographic methods supported/wanted by the remote client in CryptoProvide
/// format. The highest order one available will be selected
/// </param>
protected virtual int SelectCrypto(byte[] remoteCryptoBytes, bool replace)
{
CryptoSelect = new byte[remoteCryptoBytes.Length];
// '2' corresponds to RC4Full
if ((remoteCryptoBytes[3] & 2) == 2 && Toolbox.HasEncryption(allowedEncryption, EncryptionTypes.RC4Full))
{
CryptoSelect[3] |= 2;
if (replace)
{
Encryptor = encryptor;
Decryptor = decryptor;
}
return 2;
}
// '1' corresponds to RC4Header
if ((remoteCryptoBytes[3] & 1) == 1 && Toolbox.HasEncryption(allowedEncryption, EncryptionTypes.RC4Header))
{
CryptoSelect[3] |= 1;
if (replace)
{
Encryptor = new RC4Header();
Decryptor = new RC4Header();
}
return 1;
}
throw new EncryptionException("No valid encryption method detected");
}
