/**
* @throws IOException
* @throws KeyExchangeException
*/
protected void beginKeyExchange() throws IOException, KeyExchangeException {
log.info("Starting key exchange");
// state.setValue(TransportProtocolState.PERFORMING_KEYEXCHANGE);
String kexAlgorithm = "";
// We now have both kex inits, this is where client/server
// implemtations take over so call abstract methods
try {
// Determine the key exchange algorithm
kexAlgorithm = getKexAlgorithm();
if (log.isDebugEnabled()) {
log.debug("Key exchange algorithm: " + kexAlgorithm);
}
// Get an instance of the key exchange algortihm
SshKeyExchange kex = (SshKeyExchange) kexs.get(kexAlgorithm);
// Do the key exchange
performKeyExchange(kex);
// Record the output
exchangeHash = kex.getExchangeHash();
if (sessionIdentifier == null) {
sessionIdentifier = new byte[exchangeHash.length];
System.arraycopy(exchangeHash, 0, sessionIdentifier, 0, sessionIdentifier.length);
thread.setSessionId(sessionIdentifier);
}
hostKey = kex.getHostKey();
signature = kex.getSignature();
k = kex.getSecret();
// Send new keys
sendNewKeys();
kex.reset();
} catch (AlgorithmNotAgreedException e) {
sendDisconnect(
SshMsgDisconnect.KEY_EXCHANGE_FAILED, "No suitable key exchange algorithm was agreed");
throw new KeyExchangeException("No suitable key exchange algorithm could be agreed.");
}
}
