private byte[] getMac(uint messageVersion,
IdentityKey senderIdentityKey,
IdentityKey receiverIdentityKey,
byte[] macKey, byte[] serialized)
{
try
{
MemoryStream stream = new MemoryStream();
if (messageVersion >= 3)
{
byte[] sik = senderIdentityKey.getPublicKey().serialize();
stream.Write(sik, 0, sik.Length);
byte[] rik = receiverIdentityKey.getPublicKey().serialize();
stream.Write(rik, 0, rik.Length);
}
stream.Write(serialized, 0, serialized.Length);
byte[] fullMac = Sign.sha256sum(macKey, stream.ToArray());
return(ByteUtil.trim(fullMac, MAC_LENGTH));
}
catch (/*NoSuchAlgorithmException | java.security.InvalidKey*/ Exception e)
{
throw new Exception(e.Message);
}
}
private string getDisplayStringFor(string stableIdentifier, IdentityKey identityKey)
{
try
{
IHashAlgorithmProvider digest = HashAlgorithmProvider.OpenAlgorithm(PCLCrypto.HashAlgorithm.Sha512);
byte[] publicKey = identityKey.getPublicKey().serialize();
byte[] hash = ByteUtil.combine(ByteUtil.shortToByteArray(VERSION),
publicKey, Encoding.UTF8.GetBytes(stableIdentifier));
for (int i = 0; i < iterations; i++)
{
hash = digest.HashData(ByteUtil.combine(new byte[][] { hash, publicKey }));
}
return(getEncodedChunk(hash, 0) +
getEncodedChunk(hash, 5) +
getEncodedChunk(hash, 10) +
getEncodedChunk(hash, 15) +
getEncodedChunk(hash, 20) +
getEncodedChunk(hash, 25));
}
catch (Exception e)
{
Debug.Assert(false, e.Message);
throw e;
}
}
/// <summary>
/// Generates the display fingerprint for the given OMEMO identity public key.
/// </summary>
/// <param name="key">The OMEMO identity public key.</param>
/// <param name="twoLines">Split the fingerprint into two lines.</param>
/// <returns>A hex string representing the given OMEMO identity public key. Split up in blocks of 8 characters separated by a whitespace.</returns>
public static string generateOmemoFingerprint(IdentityKey key, bool twoLines)
{
byte[] keyRaw = getRawFromECPublicKey(key.getPublicKey());
string fingerprint = byteArrayToHexString(keyRaw);
fingerprint = Regex.Replace(fingerprint, ".{8}", "$0 ").TrimEnd();
if (twoLines)
{
fingerprint = Regex.Replace(fingerprint, ".{36}", "$0\n").TrimEnd();
}
return(fingerprint);
}
public DeviceConsistencyMessage(DeviceConsistencyCommitment commitment, byte[] serialized, IdentityKey identityKey)
{
try
{
DeviceConsistencyCodeMessage message = DeviceConsistencyCodeMessage.Parser.ParseFrom(serialized);
byte[] vrfOutputBytes = Curve.verifyVrfSignature(identityKey.getPublicKey(), commitment.toByteArray(), message.Signature.ToByteArray());
this.generation = (int)message.Generation;
this.signature = new DeviceConsistencySignature(message.Signature.ToByteArray(), vrfOutputBytes);
this.serialized = serialized;
}
catch (InvalidProtocolBufferException e)
{
throw new InvalidMessageException(e);
}
catch (InvalidKeyException e)
{
throw new InvalidMessageException(e);
}
catch (VrfSignatureVerificationFailedException e)
{
throw new InvalidMessageException(e);
}
}
public Models.Message[] GetMessages(ISharedPreferences sharedPref, User SelectedFriend, SessionStore sessionStore,
PreKeyStore preKeyStore, SignedPreKeyStore signedPreKeyStore, IdentityKeyStore identityStore, SignalProtocolAddress SelectedFriendAddress)
{
// send the server the user name
// server side does the selection and return the messages and store it in a message array.
//Send the login username and password to the server and get response
string apiUrl = "https://ycandgap.me/api_server2.php";
string apiMethod = "getMessage";
//Login_Request has two properties:username and password
Login_Request myLogin_Request = new Login_Request();
Models.Message recieveMessage = new Models.Message();
//get the login username from previow login page.
recieveMessage.MessageReceiverRegisID = Convert.ToUInt32(sharedPref.GetString("RegistrationId", string.Empty));
recieveMessage.MessageSenderRegisID = SelectedFriend.RegisterationID;
myLogin_Request.message = recieveMessage;
UserID = myLogin_Request.RegistrationID;
// make http post request
string response = Http.Post(apiUrl, new NameValueCollection()
{
{ "api_method", apiMethod },
{ "api_data", JsonConvert.SerializeObject(myLogin_Request) }
});
// decode json string to dto object
API_Response2 r = JsonConvert.DeserializeObject <API_Response2>(response);
// check response
if (r != null)
{
if (!r.IsError && !string.IsNullOrEmpty(r.MessageText))
{
SessionCipher sessionCipher = new SessionCipher(sessionStore, preKeyStore, signedPreKeyStore, identityStore, SelectedFriendAddress);
byte[] decipherMessage;
if (!sessionStore.ContainsSession(SelectedFriendAddress))
{
decipherMessage = sessionCipher.decrypt(new PreKeySignalMessage((JsonConvert.DeserializeObject <byte[]>(r.MessageText))));
}
else
{
decipherMessage = sessionCipher.decrypt(new SignalMessage((JsonConvert.DeserializeObject <byte[]>(r.MessageText))));
}
string checkMessage = Encoding.UTF8.GetString(decipherMessage);
SelectedFriend.SelectedUserMessages.Add(new Models.Message
{
MessageID = r.MessageID,
MessageSenderRegisID = r.MessageSenderRegisID,
MessageReceiverRegisID = r.MessageReceiverRegisID,
MessageText = checkMessage,
MessageTimestamp = r.MessageTimestamp
});
return(SelectedFriend.SelectedUserMessages.ToArray());
}
else
{
//if login fails, pop up an alert message. Wrong username or password or a new user
AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(this);
if (!string.IsNullOrEmpty(r.ErrorMessage))
{
dialogBuilder.SetMessage(r.ErrorMessage);
}
else
{
dialogBuilder.SetMessage("No new messages");
}
//dialogBuilder.SetPositiveButton("Ok", null);
dialogBuilder.Show();
return(null);
}
}
else
{
if (!sessionStore.ContainsSession(SelectedFriendAddress))
{
// Instantiate a SessionBuilder for a remote recipientId + deviceId tuple.
SessionBuilder sessionBuilder = new SessionBuilder(sessionStore, preKeyStore, signedPreKeyStore,
identityStore, SelectedFriendAddress);
RetrievedPreKey preKeyPublic = RetrieveSelectedFriendPublicPreKey(SelectedFriend);
IdentityKey SelectedFriendSignedPreKey = new IdentityKey(JsonConvert.DeserializeObject <byte[]>(SelectedFriend.SignedPreKey), 0);
PreKeyBundle retrievedPreKey = new PreKeyBundle(SelectedFriend.RegisterationID, 1, preKeyPublic.PrekeyID, preKeyPublic.PublicPreKey.getPublicKey()
, SelectedFriend.SignedPreKeyID, SelectedFriendSignedPreKey.getPublicKey(), JsonConvert.DeserializeObject <byte[]>(SelectedFriend.SignedPreKeySignature)
, new IdentityKey(JsonConvert.DeserializeObject <byte[]>(SelectedFriend.IdentityKey), 0));
// Build a session with a PreKey retrieved from the server.
sessionBuilder.process(retrievedPreKey);
}
return(null);
}
}
private byte[] getMac(uint messageVersion,
IdentityKey senderIdentityKey,
IdentityKey receiverIdentityKey,
byte[] macKey, byte[] serialized)
{
try
{
MemoryStream stream = new MemoryStream();
if (messageVersion >= 3)
{
byte[] sik = senderIdentityKey.getPublicKey().serialize();
stream.Write(sik, 0, sik.Length);
byte[] rik = receiverIdentityKey.getPublicKey().serialize();
stream.Write(rik, 0, rik.Length);
}
stream.Write(serialized, 0, serialized.Length);
byte[] fullMac = Sign.sha256sum(macKey, stream.ToArray());
return ByteUtil.trim(fullMac, MAC_LENGTH);
}
catch (/*NoSuchAlgorithmException | java.security.InvalidKey*/Exception e)
{
throw new Exception(e.Message);
}
}