How do I duplicate certificate authentication (Mumble (c/c++)) in Python? - c++

Question

Alright so, before I really get into this post, I am going to have to warn you that this might not be an easy fix. Whoever reads and is able to reply to this post must know a lot of c/c++, and at least some python to be able to answer the question I have above.
Basically, I have a connection method from Mumble (a VOIP client), that connects to a server and sends it an SSL certificate for authentication purposes. I also have a Python script that connects to the same Mumble VOIP server, but I don't send a certificate.
I need to modify my existing code to send a certificate, as the current Mumble client does.
--
Here is the C++ code that seems to send a certificate:
ServerHandler::ServerHandler() {
MumbleSSL::addSystemCA();
{
QList<QSslCipher> pref;
foreach(QSslCipher c, QSslSocket::defaultCiphers()) {
if (c.usedBits() < 128)
continue;
pref << c;
}
if (pref.isEmpty())
qFatal("No ciphers of at least 128 bit found");
QSslSocket::setDefaultCiphers(pref);
}
void ServerHandler::run() {
qbaDigest = QByteArray();
QSslSocket *qtsSock = new QSslSocket(this);
qtsSock->setPrivateKey(g.s.kpCertificate.second);
qtsSock->setLocalCertificate(g.s.kpCertificate.first.at(0));
QList<QSslCertificate> certs = qtsSock->caCertificates();
certs << g.s.kpCertificate.first;
qtsSock->setCaCertificates(certs);
cConnection = ConnectionPtr(new Connection(this, qtsSock));
qtsSock->setProtocol(QSsl::TlsV1);
qtsSock->connectToHostEncrypted(qsHostName, usPort);
void ServerHandler::serverConnectionConnected() {
tConnectionTimeoutTimer->stop();
qscCert = cConnection->peerCertificateChain();
qscCipher = cConnection->sessionCipher();
if (! qscCert.isEmpty()) {
const QSslCertificate &qsc = qscCert.last();
qbaDigest = sha1(qsc.publicKey().toDer());
bUdp = Database::getUdp(qbaDigest);
} else {
bUdp = true;
}
QStringList tokens = Database::getTokens(qbaDigest);
foreach(const QString &qs, tokens)
mpa.add_tokens(u8(qs));
QMap<int, CELTCodec *>::const_iterator i;
for (i=g.qmCodecs.constBegin(); i != g.qmCodecs.constEnd(); ++i)
mpa.add_celt_versions(i.key());
sendMessage(mpa);
--
And alas, this is what I do to connect to it right now (in python):
try:
self.socket.connect(self.host)
except:
print self.threadName,"Couldn't connect to server"
return
self.socket.setblocking(0)
print self.threadName,"connected to server"
--
Soo... what do I need to do more to my Python source to connect to servers that require a certificate? Because my source currently connects just fine to any mumble server with requirecert set to false. I need it to work on all servers, as this will be used on my own server (which ironically enough, has requirecerts on.)
I can pregenerate the certificate as a .p12 or w/e type file, so I don't need the program to generate the cert. I just need it to send the cert as the server wants it (as is done in the c++ I posted).
Please help me really soon! If you need more info, message me again.
Stripped out all irrelevant code, now it's just the code that deals with ssl.

Answer 1

From the C++ code it looks like you simply need to have ssl support and negotiate with the correct certification file and encrypt the payload with the correct private key. Those certifications and privates keys are most likely stored in your original program somewhere. If there are non-standard Authorities that the C++ might be loading up you'll need to find out where to put those root authorities in your python installation, or make sure python simply ignores those issues, which is less secure.
In python you can create a socket, like above, except with urllib. This library has support for HTTPs and providing the certification and private keys. URLOpener
Example Usage:
opener = urllib.URLopener(key_file = 'mykey.key', cert_file = 'mycert.cer')
self.socket = opener.open(url)
You'll probably need to make it more robust with the appropriate error checking and such, but hopefully this info will help you out.