private void runProtocolAsPlayerB()
{
if (PP.msgProtocolAborted)
{
protocolAborted();
}
if (PP.msgProtocolRestarted)
{
initializeNewPairing();
}
if (PP.currentStep == 0)
{
PP.currentStep = 2;
}
// Step 2: Generate and broadcast userB's public keypr
if (PP.currentStep == 2 && PP.msgPublicKeyA != "")
{
// generate userB's public key
CryptoManager.generateNewKeyPair();
// send it to the server who will broadcast it to everyone else
PP.msgPublicKeyB = CryptoManager.getPublicKey();
CmdPlayerBSendPublicKey(PP.msgPublicKeyB);
PP.currentStep = 4;
}
// Step 4: Acknowledge receipt of hashed value of K
if (PP.currentStep == 4 && PP.msgHashOfK != "")
{
// player B stores the values that he receives
PP.myHashOfK = PP.msgHashOfK;
// We should tell the user to wave here! Or somehow differently acknowledge that he has received what he was supposed to.
instructionsDisplay.setText("1. Wave to the other user!");
PP.currentStep = 6;
}
// Step 6: Decrypt the plaintext value of K and confirm that it's OK.
if (PP.currentStep == 6 && PP.msgEncryptedK != "")
{
PP.myPrivateK = CryptoManager.decryptWithMyKeypair(PP.msgEncryptedK);
// Check if the value K matches the commitment.
if (CryptoManager.generateHashFromString(PP.myPrivateK) != PP.myHashOfK)
{
UserSaidAbortOrCryptoFailed(); // Crypto does not match!
}
if (PP.isAttackHappening)
{
// If attack is happening, we simulate it by generating the sharedKeyK
// in way as if received data was wrong.
PP.myFinalSharedKey = PP.msgPublicKeyB + PP.myPrivateK + PP.msgPublicKeyA;
}
else
{
// If there is no attack, do it right.
PP.myFinalSharedKey = PP.msgPublicKeyA + PP.msgPublicKeyB + PP.myPrivateK;
}
setupSharedSecretVisualisation(PP.cnfgShouldUseSecretColors, PP.cnfgNumberOfSecretElements, PP.myFinalSharedKey);
if (PP.cnfgShouldUseSecretColors)
{
instructionsDisplay.setText("2. Point to the cubes in the right order.");
}
else
{
instructionsDisplay.setText("2. Follow the path with your finger.");
}
PP.currentStep = 8;
}
if (PP.currentStep == 8 && PP.msgFinalMessage != "")
{
// Check if the hash of the sharedKey is the same as the received msgFinalMessage
// If we are simulating an attack, this won't be detected since the attacker would supposedly be smart enough here?
if (PP.isAttackHappening || CryptoManager.generateHashFromString(PP.myFinalSharedKey) == PP.msgFinalMessage)
{
protocolSuccessful();
}
else
{
UserSaidAbortOrCryptoFailed(); // CryptoFailed
}
}
}
