private void runProtocolAsPlayerA() // Player A is Server
{
if (PP.msgProtocolAborted)
{
protocolAborted();
}
if (PP.msgProtocolRestarted)
{
initializeNewPairing();
}
// Step 0: once player B has connected, send the shared protocol parameters.
// For now, we send:
// -- which type of confirmation step are we using: secretColors or secretNumbers
// -- how many secret elements should there be
if (PP.currentStep == 0 && NM.numPlayers == 2)
{
// Choose the number of secret elements
System.Random rand = new System.Random();
PP.cnfgNumberOfSecretElements = secretElementSizes[rand.Next(0, secretElementSizes.Length)];
RpcPlayerASendProtocolParameters(PP.cnfgShouldUseSecretColors, PP.cnfgNumberOfSecretElements, PP.shouldAttackHappen());
PP.currentStep = 1;
}
// Step 1: User A sends his public key
if (PP.currentStep == 1 && PP.msgPublicKeyA == "")
{
PP.AddTimeStampsToSteps(PP.currentStep);
// generate userA's key pair
CryptoManager.generateNewKeyPair();
// send it to the server who will broadcast it to everyone else
RpcPlayerASendPublicKey(CryptoManager.getPublicKey());
PP.currentStep = 3; // go to the next step in the protocol
}
// Step 3: After receiving B's public key, user A makes a commitment on some value K
if (PP.currentStep == 3 && PP.msgPublicKeyB != "")
{
PP.AddTimeStampsToSteps(PP.currentStep);
// Player A generates those himself
PP.myPrivateK = CryptoManager.generateRandomNonce();
PP.myHashOfK = CryptoManager.generateHashFromString(PP.myPrivateK);
RpcPlayerASendHashOfK(PP.myHashOfK);
instructionsDisplay.setText("1. When other user waves, click on their cube.");
PP.currentStep = 5;
}
// Step 5: After user A confirms that he has received an ACK from user B on the visual channel, we proceed
if (PP.currentStep == 5 && PP.userAConfirmedVisualACK)
{
PP.AddTimeStampsToSteps(PP.currentStep);
// Encrypt the plaintext K using B's public key
string myEncryptedK = CryptoManager.encrypt(PP.myPrivateK, PP.msgPublicKeyB);
RpcPlayerASendEncryptedK(myEncryptedK);
PP.msgEncryptedK = myEncryptedK;
// I can now also set all the colors
PP.myFinalSharedKey = PP.msgPublicKeyA + PP.msgPublicKeyB + PP.myPrivateK;
setupSharedSecretVisualisation(PP.cnfgShouldUseSecretColors, PP.cnfgNumberOfSecretElements, PP.myFinalSharedKey);
instructionsDisplay.setText("2. If gestures are correct, click on their cube.\nIf they make a mistake, say \"Abort\"");
PP.currentStep = 7;
}
if (PP.currentStep == 7 && PP.userAConfirmedPairingSuccessful)
{
PP.AddTimeStampsToSteps(PP.currentStep);
// Send a message in which a hash of our shared key is encrypted with B's private key
string hashedSharedKey = CryptoManager.generateHashFromString(PP.myFinalSharedKey);
RpcPlayerASendFinalMessage(hashedSharedKey);
protocolSuccessful();
}
}
