/// <summary>
/// Construct and send CLIENT_LICENSE_INFO
/// Meanwhile, generate the two licensing keys: licensing encryption key and MAC salt key.
/// </summary>
public void SendClientLicenseInformation(KeyExchangeAlg preferredKeyExchangeAlg, uint platformId, byte[] licenseInfo, CLIENT_HARDWARE_ID clientHardwareID)
{
CLIENT_LICENSE_INFO info = new CLIENT_LICENSE_INFO();
info.PreferredKeyExchangeAlg = preferredKeyExchangeAlg;
info.PlatformId = platformId;
info.LicenseInfo.blobData = licenseInfo;
info.LicenseInfo.wBlobLen = (ushort)licenseInfo.Length;
info.LicenseInfo.wBlobType = wBlobType_Values.BB_DATA_BLOB;
var random = new Random();
clientRandom = new byte[32];
random.NextBytes(clientRandom);
info.ClientRandom = clientRandom;
preMasterSecret = new byte[48];
random.NextBytes(preMasterSecret);
EncryptionAlgorithm.GenerateLicensingKeys(preMasterSecret, clientRandom, serverRandom, out macSaltKey, out licensingEncryptionKey);
if (macSaltKey == null)
{
throw new Exception("The generated MAC-salt-key should not be NULL!");
}
if (licensingEncryptionKey == null)
{
throw new Exception("The generated LicensingEncryptionKey should not be NULL!");
}
info.EncryptedPreMasterSecret.blobData = RdpbcgrUtility.GenerateEncryptedRandom(preMasterSecret, publicExponent, modulus);
info.EncryptedPreMasterSecret.wBlobLen = (ushort)info.EncryptedPreMasterSecret.blobData.Length;
info.EncryptedPreMasterSecret.wBlobType = wBlobType_Values.BB_RANDOM_BLOB;
CLIENT_HARDWARE_ID hardwareID = new CLIENT_HARDWARE_ID();
hardwareID = clientHardwareID;
info.EncryptedHWID.wBlobType = wBlobType_Values.BB_ENCRYPTED_DATA_BLOB;
var hardwareIDBytes = TypeMarshal.ToBytes <CLIENT_HARDWARE_ID>(hardwareID);
info.EncryptedHWID.blobData = RC4(hardwareIDBytes);
info.EncryptedHWID.wBlobLen = (ushort)info.EncryptedHWID.blobData.Length;
// MACData (16 bytes): An array of 16 bytes containing an MD5 digest (Message Authentication Code (MAC))
// that is generated over the unencrypted Client Hardware Identification structure.
info.MACData = EncryptionAlgorithm.GenerateNonFIPSDataSignature(macSaltKey, hardwareIDBytes, 16 * 8); // n is 16 * 8 bits.
TS_LICENSE_PDU pdu = ConstructLicensePDU(bMsgType_Values.LICENSE_INFO, new LicensingMessage {
ClientLicenseInfo = info
});
rdpbcgrClient.SendBytes(pdu.ToBytes());
}
/// <summary>
/// Construct and send CLIENT_PLATFORM_CHALLENGE_RESPONSE with encrypted Platform Challeng Response
/// </summary>
public void SendClientPlatformChallengeResponse(CLIENT_HARDWARE_ID clientHardwareID)
{
CLIENT_PLATFORM_CHALLENGE_RESPONSE response = new CLIENT_PLATFORM_CHALLENGE_RESPONSE();
PLATFORM_CHALLENGE_RESPONSE_DATA challengeData = new PLATFORM_CHALLENGE_RESPONSE_DATA();
challengeData.pbChallenge = platformChallenge;
challengeData.cbChallenge = (ushort)platformChallenge.Length;
challengeData.wClientType = 0x0100;
challengeData.wVersion = 0x0100;
challengeData.wLicenseDetailLevel = 0x0003;
response.EncryptedPlatformChallengResponse.wBlobType = wBlobType_Values.BB_ENCRYPTED_DATA_BLOB;
var challengeDataBytes = TypeMarshal.ToBytes <PLATFORM_CHALLENGE_RESPONSE_DATA>(challengeData);
response.EncryptedPlatformChallengResponse.blobData = RC4(challengeDataBytes);
response.EncryptedPlatformChallengResponse.wBlobLen = (ushort)response.EncryptedPlatformChallengResponse.blobData.Length;
CLIENT_HARDWARE_ID hardwareID = new CLIENT_HARDWARE_ID();
hardwareID = clientHardwareID;
response.EncryptedHWID.wBlobType = wBlobType_Values.BB_ENCRYPTED_DATA_BLOB;
var hardwareIDBytes = TypeMarshal.ToBytes <CLIENT_HARDWARE_ID>(hardwareID);
response.EncryptedHWID.blobData = RC4(hardwareIDBytes);
response.EncryptedHWID.wBlobLen = (ushort)response.EncryptedHWID.blobData.Length;
// MACData (16 bytes): An array of 16 bytes containing an MD5 digest (MAC) generated over the Platform Challenge Response Data and decrypted Client Hardware Identification.
var data = challengeDataBytes.Concat(hardwareIDBytes).ToArray();
response.MACData = EncryptionAlgorithm.GenerateNonFIPSDataSignature(macSaltKey, data, 16 * 8); // n is 16 * 8 bits.
TS_LICENSE_PDU pdu = ConstructLicensePDU(bMsgType_Values.PLATFORM_CHALLENGE_RESPONSE, new LicensingMessage {
ClientPlatformChallengeResponse = response
});
rdpbcgrClient.SendBytes(pdu.ToBytes());
}
/// <summary>
/// Verify if the MACData received from server is valid or not.
/// </summary>
/// <param name="receivedMAC">The MACData received from Server</param>
/// <param name="decryptedData">The decrypted data from Server, which is protected by MACData</param>
/// <returns>If the received MAC is valid or not</returns>
public bool VerifyServerMAC(byte[] receivedMAC, byte[] decryptedData)
{
var calculatedMAC = EncryptionAlgorithm.GenerateNonFIPSDataSignature(macSaltKey, decryptedData, 16 * 8);
return(Enumerable.SequenceEqual(receivedMAC, calculatedMAC));
}