public function processResponse($keyExchangeMessage)
{
$sessionRecord = $this->sessionStore->loadSession($this->recipientId, $this->deviceId);
$sessionState = $sessionRecord->getSessionState();
$hasPendingKeyExchange = $sessionState->hasPendingKeyExchange();
$isSimultaneousInitiateResponse = $keyExchangeMessage->isResponseForSimultaneousInitiate();
if (!$hasPendingKeyExchange || $sessionState->getPendingKeyExchangeSequence() != $keyExchangeMessage->getSequence()) {
Log::warn('procResponse', 'No matching sequence for response. Is simultaneous initiate response:' . ($isSimultaneousInitiateResponse ? 'true' : 'false'));
if (!$isSimultaneousInitiateResponse) {
throw new StaleKeyExchangeException();
} else {
return;
}
}
$parameters = new SymmetricBuilder();
$parameters->setOurBaseKey($sessionRecord->getSessionState()->getPendingKeyExchangeBaseKey())->setOurRatchetKey($sessionRecord->getSessionState()->getPendingKeyExchangeRatchetKey())->setOurIdentityKey($sessionRecord->getSessionState()->getPendingKeyExchangeIdentityKey())->setTheirBaseKey($keyExchangeMessage->getBaseKey())->setTheirRatchetKey($keyExchangeMessage->getRatchetKey())->setTheirIdentityKey($keyExchangeMessage->getIdentityKey());
if (!$sessionRecord->isFresh()) {
$sessionRecord->archiveCurrentState();
}
RatchetingSession::initializeSession($sessionRecord->getSessionState(), min($keyExchangeMessage->getMaxVersion(), CiphertextMessage::CURRENT_VERSION), $parameters->create());
if ($sessionRecord->getSessionState()->getSessionVersion() >= 3 && !Curve::verifySignature($keyExchangeMessage->getIdentityKey()->getPublicKey(), $keyExchangeMessage->getBaseKey()->serialize(), $keyExchangeMessage->getBaseKeySignature())) {
throw new InvalidKeyException("Base key signature doesn't match!");
}
$this->sessionStore->storeSession($this->recipientId, $this->deviceId, $sessionRecord);
$this->identityKeyStore->saveIdentity($this->recipientId, $keyExchangeMessage->getIdentityKey());
}
protected function initializeSessionsV3($aliceSessionState, $bobSessionState)
{
$aliceIdentityKeyPair = Curve::generateKeyPair();
$aliceIdentityKey = new IdentityKeyPair(new IdentityKey($aliceIdentityKeyPair->getPublicKey()), $aliceIdentityKeyPair->getPrivateKey());
$aliceBaseKey = Curve::generateKeyPair();
$aliceEphemeralKey = Curve::generateKeyPair();
$alicePreKey = $aliceBaseKey;
$bobIdentityKeyPair = Curve::generateKeyPair();
$bobIdentityKey = new IdentityKeyPair(new IdentityKey($bobIdentityKeyPair->getPublicKey()), $bobIdentityKeyPair->getPrivateKey());
$bobBaseKey = Curve::generateKeyPair();
$bobEphemeralKey = $bobBaseKey;
$bobPreKey = Curve::generateKeyPair();
$aliceParameters = AliceAxolotlParameters::newBuilder()->setOurBaseKey($aliceBaseKey)->setOurIdentityKey($aliceIdentityKey)->setTheirOneTimePreKey(null)->setTheirRatchetKey($bobEphemeralKey->getPublicKey())->setTheirSignedPreKey($bobBaseKey->getPublicKey())->setTheirIdentityKey($bobIdentityKey->getPublicKey())->create();
$bobParameters = BobAxolotlParameters::newBuilder()->setOurRatchetKey($bobEphemeralKey)->setOurSignedPreKey($bobBaseKey)->setOurOneTimePreKey(null)->setOurIdentityKey($bobIdentityKey)->setTheirIdentityKey($aliceIdentityKey->getPublicKey())->setTheirBaseKey($aliceBaseKey->getPublicKey())->create();
RatchetingSession::initializeSessionAsAlice($aliceSessionState, 3, $aliceParameters);
RatchetingSession::initializeSessionAsBob($bobSessionState, 3, $bobParameters);
}