/**
* Does the actual work for decrypting - if version does not match current cipher then tries the
* previous cipher
*/
private Message decryptMessage(Cipher cipher, Message msg) throws Exception {
EncryptHeader hdr = (EncryptHeader) msg.getHeader(this.id);
if (!Arrays.equals(hdr.getVersion(), getSymVersion())) {
log.warn(
"attempting to use stored cipher as message does not use current encryption version ");
cipher = keyMap.get(new AsciiString(hdr.getVersion()));
if (cipher == null) {
log.warn("unable to find a matching cipher in previous key map");
return null;
}
log.trace("decrypting using previous cipher version");
synchronized (cipher) {
return _decrypt(cipher, msg, hdr.encryptEntireMessage());
}
}
return _decrypt(cipher, msg, hdr.encryptEntireMessage());
}
protected void handleUpEvent(Message msg, EncryptHeader hdr) {
// check if we had some sort of encrypt control header if using supplied key we should not
// process it
if (suppliedKey) {
log.warn("we received an encrypt header of %s while in configured mode", hdr.getType());
return;
}
// see what sort of encrypt control message we have received
switch (hdr.getType()) {
// if a key request
case EncryptHeader.KEY_REQUEST:
log.debug("received a key request from peer %s", msg.getSrc());
// if a key request send response key back
try {
// extract peer's public key
PublicKey tmpKey = generatePubKey(msg.getBuffer());
// send back the secret key we have
sendSecretKey(getSecretKey(), tmpKey, msg.getSrc());
} catch (Exception e) {
log.warn("unable to reconstitute peer's public key");
}
break;
case EncryptHeader.SECRETKEY:
log.debug("received a secretkey response from keyserver %s", msg.getSrc());
try {
SecretKey tmp = decodeKey(msg.getBuffer());
if (tmp == null) sendKeyRequest(); // unable to understand response, let's try again
else {
// otherwise lets set the returned key as the shared key
setKeys(tmp, hdr.getVersion());
log.debug("decoded secretkey response");
}
} catch (Exception e) {
log.warn("unable to process received public key", e);
}
break;
default:
log.warn("received ignored encrypt header of %s", hdr.getType());
break;
}
}