public void StoreSession(OmemoProtocolAddress address, OmemoSessionModel session)
{
OmemoDeviceModel device;
if (string.Equals(address.BARE_JID, dbAccount.bareJid))
{
device = dbAccount.omemoInfo.devices.Where(d => address.DEVICE_ID == d.deviceId).FirstOrDefault();
}
else
{
ChatModel chat;
using (SemaLock semaLock = DataCache.INSTANCE.NewChatSemaLock())
{
chat = DataCache.INSTANCE.GetChat(dbAccount.bareJid, address.BARE_JID, semaLock);
}
if (chat is null)
{
throw new InvalidOperationException("Failed to store session. Chat '" + address.BARE_JID + "' does not exist.");
}
device = chat.omemoInfo.devices.Where(d => d.deviceId == address.DEVICE_ID).FirstOrDefault();
}
if (device is null)
{
throw new InvalidOperationException("Failed to store session. Device '" + address.ToString() + "' does not exist.");
}
if (device.session is null)
{
device.session = session;
}
bool newSession = device.session.id != session.id;
OmemoSessionModel oldSession = null;
if (newSession)
{
oldSession = device.session;
device.session = session;
}
device.Update();
// Remove the old session:
if (newSession)
{
using (MainDbContext ctx = new MainDbContext())
{
ctx.Remove(oldSession);
}
}
}
private async Task buildSessionForDevicesAsync(OmemoDeviceGroup deviceGroup, IList <OmemoProtocolAddress> devices)
{
if (devices.Count <= 0)
{
return;
}
OmemoProtocolAddress device = devices[0];
devices.RemoveAt(0);
OmemoFingerprint fingerprint = OMEMO_HELPER.OMEMO_STORAGE.LoadFingerprint(device);
// Check if there exists already a session for this device:
OmemoSessionModel session = OMEMO_HELPER.OMEMO_STORAGE.LoadSession(device);
if (session is null)
{
// Try to build a new session by requesting the devices bundle information:
OmemoBundleInformationResultMessage bundleMsg = await requestBundleInformationAsync(device);
if (!(bundleMsg is null) && !(bundleMsg.BUNDLE_INFO.bundle is null))
{
int preKeyIndex = bundleMsg.BUNDLE_INFO.bundle.GetRandomPreKeyIndex();
session = new OmemoSessionModel(bundleMsg.BUNDLE_INFO.bundle, preKeyIndex, CONNECTION.account.omemoIdentityKey);
// Validate fingerprints:
if (fingerprint is null)
{
fingerprint = new OmemoFingerprint(bundleMsg.BUNDLE_INFO.bundle.identityKey, device);
OMEMO_HELPER.OMEMO_STORAGE.StoreFingerprint(fingerprint);
}
else
{
OmemoFingerprint receivedFingerprint = new OmemoFingerprint(bundleMsg.BUNDLE_INFO.bundle.identityKey, device);
// Make sure the fingerprint did not change or somebody is performing an attack:
if (!fingerprint.checkIdentityKey(receivedFingerprint.IDENTITY_KEY))
{
Logger.Warn("[OmemoSessionBuildHelper] Unable to establish session with " + device.ToString() + " - other fingerprint received than stored locally.");
await buildSessionForDevicesAsync(deviceGroup, devices);
return;
}
}
}
else
{
Logger.Warn("[OmemoSessionBuildHelper] Unable to establish session with: " + device.ToString());
}
}
