//--------------------------------------------------------Misc Methods:---------------------------------------------------------------\\
#region --Misc Methods (Public)--
/// <summary>
/// Loads all OMEMO keys from the given store.
/// </summary>
/// <param name="omemoStore">A persistent store for all the OMEMO related data (e.g. device ids and keys).</param>
/// <returns>Returns true on success.</returns>
public bool loadOmemoKeys(IOmemoStore omemoStore)
{
if (!omemoKeysGenerated)
{
Logger.Error("Failed to load OMEMO keys for: " + getBareJid() + " - run generateOmemoKeys() first!");
return(false);
}
OMEMO_PRE_KEYS.Clear();
OMEMO_PRE_KEYS.AddRange(omemoStore.LoadPreKeys());
if (OMEMO_PRE_KEYS.Count <= 0)
{
Logger.Error("Failed to load OMEMO prekeys for: " + getBareJid());
return(false);
}
omemoSignedPreKeyPair = omemoStore.LoadSignedPreKey(omemoSignedPreKeyId);
if (omemoSignedPreKeyPair is null)
{
Logger.Error("Failed to load OMEMO signed prekey pair for: " + getBareJid());
return(false);
}
Logger.Info("Successfully loaded OMEMO keys for: " + getBareJid());
return(true);
}
//--------------------------------------------------------Constructor:----------------------------------------------------------------\\
#region --Constructors--
/// <summary>
/// Basic Constructor
/// </summary>
/// <history>
/// 06/08/2018 Created [Fabian Sauter]
/// </history>
public OmemoHelper(XmppConnection connection, IOmemoStore omemoStore)
{
CONNECTION = connection;
OMEMO_STORE = omemoStore;
OMEMO_SESSIONS = new Dictionary <string, OmemoSession>();
MESSAGE_CACHE = new Dictionary <string, Tuple <List <OmemoMessageMessage>, OmemoSessionBuildHelper> >();
reset();
}
/// <summary>
/// Stores all OMEMO keys in the given store.
/// </summary>
/// <param name="omemoStore">A persistent store for all the OMEMO related data (e.g. device ids and keys).</param>
/// <returns>Returns true on success.</returns>
public bool storeOmemoKeys(IOmemoStore omemoStore)
{
if (!checkOmemoKeys())
{
Logger.Error("Failed to save OMEMO keys for: " + getBareJid());
return(false);
}
omemoStore.StoreSignedPreKey(omemoSignedPreKeyId, omemoSignedPreKeyPair);
omemoStore.StorePreKeys(OMEMO_PRE_KEYS);
return(true);
}
public void replaceOmemoPreKey(uint preKeyId, IOmemoStore omemoStore)
{
// Remove key:
foreach (PreKeyRecord key in OMEMO_PRE_KEYS)
{
if (key.getId() == preKeyId)
{
OMEMO_PRE_KEYS.Remove(key);
omemoStore.RemovePreKey(preKeyId);
break;
}
}
// Generate new key:
PreKeyRecord newKey = KeyHelper.generatePreKeys(preKeyId, 1)[0];
OMEMO_PRE_KEYS.Add(newKey);
omemoStore.StorePreKey(newKey.getId(), newKey);
omemoBundleInfoAnnounced = false;
}
/// <summary>
/// Enables OMEMO encryption for messages for this
/// Has to be enabled before connecting.
/// </summary>
/// <param name="omemoStore">A persistent store for all the OMEMO related data (e.g. device ids and keys).</param>
/// <returns>Returns true on success.</returns>
public bool EnableOmemo(IOmemoStore omemoStore)
{
if (state != ConnectionState.DISCONNECTED)
{
throw new InvalidOperationException(LOGGER_TAG + "Unable to enable OMEMO. state != " + ConnectionState.DISCONNECTED.ToString() + " - " + state.ToString());
}
// Load OMEMO keys for the current account:
if (!account.omemoKeysGenerated)
{
Logger.Error(LOGGER_TAG + "Failed to enable OMEMO for account: " + account.getBareJid() + " - generate OMEMO keys first!");
omemoHelper = null;
return(false);
}
else if (!account.loadOmemoKeys(omemoStore))
{
omemoHelper = null;
return(false);
}
omemoHelper = new OmemoHelper(this, omemoStore);
return(true);
}
/// <summary>
/// Enables OMEMO encryption for messages for this connection.
/// Has to be enabled before connecting.
/// </summary>
/// <param name="omemoStore">A persistent store for all the OMEMO related data (e.g. device ids and keys).</param>
/// <returns>Returns true on success.</returns>
public bool enableOmemo(IOmemoStore omemoStore)
{
return(connection.EnableOmemo(omemoStore));
}
/// <summary>
/// Validates if the given identity public key should be trusted.
/// </summary>
/// <param name="address">The signal protocol address corresponding to the given public identity key.</param>
/// <param name="publicKey">The public identity key we want to validate.</param>
/// <param name="omemoStore">The OMEMO store that keeps all OMEMO related keys.</param>
/// <returns>True if we trust else false.</returns>
private Task <bool> isFingerprintTrustedAsync(SignalProtocolAddress address, ECPublicKey publicKey, IOmemoStore omemoStore)
{
return(Task.Run(() =>
{
OmemoFingerprint fingerprint = omemoStore.LoadFingerprint(address);
if (!(fingerprint is null))
{
if (!fingerprint.checkIdentityKey(publicKey))
{
Logger.Warn("Received not OMEMO encrypted message with a not matching public identity key from: " + address.ToString());
return false;
}
fingerprint.lastSeen = DateTime.Now;
}