// This test validates that the construction and parsing of the message integrity attribute in a stun message works as expected
// The test also validates both short term and long term credential modes with or without the presence of a fingerprint attribute
HRESULT CTestIntegrity::TestMessageIntegrity(bool fWithFingerprint, bool fLongCredentials)
{
HRESULT hr = S_OK;
const char* pszUserName = "******";
const char* pszRealm = "stunrealm";
const char* pszPassword = "******";
CStunMessageBuilder builder;
CStunMessageReader reader;
uint8_t *pMsg = NULL;
size_t sizeMsg = 0;
CStunMessageReader::ReaderParseState state;
CRefCountedBuffer spBuffer;
builder.AddBindingRequestHeader();
builder.AddRandomTransactionId(NULL);
builder.AddUserName(pszUserName);
builder.AddRealm(pszRealm);
if (fLongCredentials == false)
{
Chk(builder.AddMessageIntegrityShortTerm(pszPassword));
}
else
{
Chk(builder.AddMessageIntegrityLongTerm(pszUserName, pszRealm, pszPassword));
}
if (fWithFingerprint)
{
builder.AddFingerprintAttribute();
}
Chk(builder.GetResult(&spBuffer));
pMsg = spBuffer->GetData();
sizeMsg = spBuffer->GetSize();
state = reader.AddBytes(pMsg, sizeMsg);
ChkIfA(state != CStunMessageReader::BodyValidated, E_FAIL);
ChkIfA(reader.HasMessageIntegrityAttribute()==false, E_FAIL);
if (fLongCredentials == false)
{
ChkA(reader.ValidateMessageIntegrityShort(pszPassword));
}
else
{
ChkA(reader.ValidateMessageIntegrityLong(pszUserName, pszRealm, pszPassword));
}
Cleanup:
return hr;
}
HRESULT CStunThreadMessageHandler::ProcessBindingRequest(CStunMessageReader& reader)
{
HRESULT hrTmp;
bool fRequestHasPaddingAttribute = false;
SocketRole socketOutput = _message.localSocket;
StunChangeRequestAttribute changerequest = {};
bool fSendOtherAddress = false;
bool fSendOriginAddress = false;
SocketRole socketOther;
CSocketAddress addrOrigin;
CSocketAddress addrOther;
CStunMessageBuilder builder;
uint16_t paddingSize = 0;
bool fLegacyFormat = false; // set to true if the client appears to be rfc3489 based instead of based on rfc 5789
_spResponseBuffer->SetSize(0);
builder.GetStream().Attach(_spResponseBuffer, true);
fLegacyFormat = reader.IsMessageLegacyFormat();
// check for an alternate response port
// check for padding attribute (todo - figure out how to inject padding into the response)
// check for a change request and validate we can do it. If so, set _socketOutput. If not, fill out _error and return.
// determine if we have an "other" address to notify the caller about
// did the request come with a padding request
if (SUCCEEDED(reader.GetPaddingAttributeSize(&paddingSize)))
{
// todo - figure out how we're going to get the MTU size of the outgoing interface
fRequestHasPaddingAttribute = true;
}
// as per 5780, section 6.1, If the Request contained a PADDING attribute...
// "If the Request also contains the RESPONSE-PORT attribute the server MUST return an error response of type 400."
if (_fRequestHasResponsePort && fRequestHasPaddingAttribute)
{
_error.errorcode = STUN_ERROR_BADREQUEST;
return E_FAIL;
}
// handle change request logic and figure out what "other-address" attribute is going to be
if (SUCCEEDED(reader.GetChangeRequest(&changerequest)))
{
if (changerequest.fChangeIP)
{
socketOutput = SocketRoleSwapIP(socketOutput);
}
if(changerequest.fChangePort)
{
socketOutput = SocketRoleSwapPort(socketOutput);
}
// IsValidSocketRole just validates the enum, not whether or not we can send on it
ASSERT(IsValidSocketRole(socketOutput));
// now, make sure we have the ability to send from another socket
if (_spStunResponder->HasAddress(socketOutput) == false)
{
// send back an error. We're being asked to respond using another address that we don't have a socket for
_error.errorcode = STUN_ERROR_BADREQUEST;
return E_FAIL;
}
}
// If we're only working one socket, then that's ok, we just don't send back an "other address" unless we have all four sockets confgiured
// now here's a problem. If we binded to "INADDR_ANY", all of the sockets will have "0.0.0.0" for an address (same for IPV6)
// So we effectively can't send back "other address" if don't really know our own IP address
// Fortunately, recvfromex and the ioctls on the socket allow address discovery a bit better
fSendOtherAddress = (_spStunResponder->HasAddress(RolePP) && _spStunResponder->HasAddress(RolePA) && _spStunResponder->HasAddress(RoleAP) && _spStunResponder->HasAddress(RoleAA));
if (fSendOtherAddress)
{
socketOther = SocketRoleSwapIP(SocketRoleSwapPort(_message.localSocket));
hrTmp = _spStunResponder->GetSocketAddressForRole(socketOther, &addrOther);
ASSERT(SUCCEEDED(hrTmp));
// so if our ip address is "0.0.0.0", disable this attribute
fSendOtherAddress = (SUCCEEDED(hrTmp) && (addrOther.IsIPAddressZero()==false));
}
// What's our address origin?
VERIFY(SUCCEEDED(_spStunResponder->GetSocketAddressForRole(socketOutput, &addrOrigin)));
if (addrOrigin.IsIPAddressZero())
{
// Since we're sending back from the IP address we received on, we can just use the address the message came in on
// Otherwise, we don't actually know it
if (socketOutput == _message.localSocket)
{
addrOrigin = _message.localAddr;
}
}
fSendOriginAddress = (false == addrOrigin.IsIPAddressZero());
// Success - we're all clear to build the response
_socketOutput = socketOutput;
_spResponseBuffer->SetSize(0);
builder.GetStream().Attach(_spResponseBuffer, true);
builder.AddHeader(StunMsgTypeBinding, StunMsgClassSuccessResponse);
builder.AddTransactionId(_transid);
builder.AddMappedAddress(_message.remoteAddr);
if (fLegacyFormat == false)
{
builder.AddXorMappedAddress(_message.remoteAddr);
}
if (fSendOriginAddress)
{
builder.AddResponseOriginAddress(addrOrigin);
}
if (fSendOtherAddress)
{
builder.AddOtherAddress(addrOther, fLegacyFormat); // pass true to send back CHANGED-ADDRESS, otherwise, pass false to send back OTHER-ADDRESS
}
// finally - if we're supposed to have a message integrity attribute as a result of authorization, add it at the very end
if (_integrity.fSendWithIntegrity)
{
if (_integrity.fUseLongTerm == false)
{
builder.AddMessageIntegrityShortTerm(_integrity.szPassword);
}
else
{
builder.AddMessageIntegrityLongTerm(_integrity.szUser, _integrity.szRealm, _integrity.szPassword);
}
}
builder.FixLengthField();
return S_OK;
}