WIP: clean up signal protocol

libsession/src/main/java/org/session/libsession/messaging/utilities/DotNetAPI.kt

@@ -12,7 +12,7 @@ import org.session.libsession.snode.SnodeAPI
 import org.session.libsession.messaging.fileserver.FileServerAPI
 
 import org.session.libsignal.utilities.logging.Log
-import org.session.libsignal.libsignal.loki.DiffieHellman
+import org.session.libsignal.utilities.DiffieHellman
 import org.session.libsignal.service.api.crypto.ProfileCipherOutputStream
 import org.session.libsignal.service.api.messages.SignalServiceAttachment
 import org.session.libsignal.service.api.push.exceptions.NonSuccessfulResponseCodeException

libsignal/src/main/java/org/session/libsignal/libsignal/SessionCipher.java

@@ -8,7 +8,6 @@ package org.session.libsignal.libsignal;
 import org.session.libsignal.libsignal.ecc.Curve;
 import org.session.libsignal.libsignal.ecc.ECKeyPair;
 import org.session.libsignal.libsignal.ecc.ECPublicKey;
-import org.session.libsignal.libsignal.loki.FallbackSessionCipher;
 import org.session.libsignal.libsignal.protocol.CiphertextMessage;
 import org.session.libsignal.libsignal.protocol.PreKeySignalMessage;
 import org.session.libsignal.libsignal.protocol.SignalMessage;
@@ -332,7 +331,7 @@ public class SessionCipher {
     synchronized (SESSION_LOCK) {
       if (!sessionStore.containsSession(remoteAddress)) {
           // Loki - If we have no session then we must be using the FallbackSessionCipher
-          return FallbackSessionCipher.getSessionVersion();
+          return 3;
       }
 
       SessionRecord record = sessionStore.loadSession(remoteAddress);

libsignal/src/main/java/org/session/libsignal/libsignal/loki/ClosedGroupCiphertextMessage.kt

@@ -1,39 +0,0 @@
-package org.session.libsignal.libsignal.loki
-
-import com.google.protobuf.ByteString
-import org.session.libsignal.utilities.logging.Log
-import org.session.libsignal.libsignal.protocol.CiphertextMessage
-import org.session.libsignal.libsignal.protocol.SignalProtos
-
-class ClosedGroupCiphertextMessage(val ivAndCiphertext: ByteArray, val senderPublicKey: ByteArray, val keyIndex: Int) : CiphertextMessage {
-    private val serialized: ByteArray
-
-    companion object {
-
-        fun from(serialized: ByteArray): ClosedGroupCiphertextMessage? {
-            try {
-                val proto = SignalProtos.ClosedGroupCiphertextMessage.parseFrom(serialized)
-                return ClosedGroupCiphertextMessage(proto.ciphertext.toByteArray(), proto.senderPublicKey.toByteArray(), proto.keyIndex)
-            } catch (exception: Exception) {
-                Log.d("Loki", "Couldn't parse proto due to error: $exception.")
-                return null
-            }
-        }
-    }
-
-    init {
-        val builder = SignalProtos.ClosedGroupCiphertextMessage.newBuilder()
-        builder.ciphertext = ByteString.copyFrom(ivAndCiphertext)
-        builder.senderPublicKey = ByteString.copyFrom(senderPublicKey)
-        builder.keyIndex = keyIndex
-        serialized = builder.build().toByteArray()
-    }
-
-    override fun getType(): Int {
-        return CiphertextMessage.CLOSED_GROUP_CIPHERTEXT
-    }
-
-    override fun serialize(): ByteArray {
-        return serialized
-    }
-}

libsignal/src/main/java/org/session/libsignal/libsignal/loki/FallbackMessage.kt

@@ -1,14 +0,0 @@
-package org.session.libsignal.libsignal.loki
-
-import org.session.libsignal.libsignal.protocol.CiphertextMessage
-
-class FallbackMessage(private val paddedMessageBody: ByteArray) : CiphertextMessage {
-
-    override fun serialize(): ByteArray {
-        return paddedMessageBody
-    }
-
-    override fun getType(): Int {
-        return CiphertextMessage.FALLBACK_MESSAGE_TYPE
-    }
-}

libsignal/src/main/java/org/session/libsignal/libsignal/loki/FallbackSessionCipher.kt

@@ -1,51 +0,0 @@
-package org.session.libsignal.libsignal.loki
-
-import org.whispersystems.curve25519.Curve25519
-import org.session.libsignal.utilities.Hex
-import org.session.libsignal.service.loki.utilities.removing05PrefixIfNeeded
-
-/**
- * A session cipher that uses the current user's private key along with a contact's public key to encrypt data.
- */
-class FallbackSessionCipher(private val userPrivateKey: ByteArray, private val hexEncodedContactPublicKey: String) {
-
-    private val contactPublicKey by lazy {
-        val hexEncodedContactPublicKey = hexEncodedContactPublicKey.removing05PrefixIfNeeded()
-        Hex.fromStringCondensed(hexEncodedContactPublicKey)
-    }
-
-    private val symmetricKey: ByteArray?
-        get() {
-            try {
-                val curve = Curve25519.getInstance(Curve25519.BEST)
-                return curve.calculateAgreement(contactPublicKey, userPrivateKey)
-            } catch (e: Exception) {
-                e.printStackTrace()
-                return null
-            }
-        }
-
-    companion object {
-        @JvmStatic val sessionVersion = 3
-    }
-
-    fun encrypt(paddedMessageBody: ByteArray): ByteArray? {
-        val symmetricKey = symmetricKey ?: return null
-        try {
-            return DiffieHellman.encrypt(paddedMessageBody, symmetricKey)
-        } catch (e: Exception) {
-            e.printStackTrace()
-            return null
-        }
-    }
-
-    fun decrypt(bytes: ByteArray): ByteArray? {
-        val symmetricKey = symmetricKey ?: return null
-        try {
-            return DiffieHellman.decrypt(bytes, symmetricKey)
-        } catch (e: Exception) {
-            e.printStackTrace()
-            return null
-        }
-    }
-}

libsignal/src/main/java/org/session/libsignal/metadata/SealedSessionCipher.java

@@ -23,7 +23,6 @@ import org.session.libsignal.libsignal.ecc.ECKeyPair;
 import org.session.libsignal.libsignal.ecc.ECPrivateKey;
 import org.session.libsignal.libsignal.ecc.ECPublicKey;
 import org.session.libsignal.libsignal.kdf.HKDFv3;
-import org.session.libsignal.libsignal.loki.FallbackSessionCipher;
 import org.session.libsignal.libsignal.protocol.CiphertextMessage;
 import org.session.libsignal.libsignal.protocol.PreKeySignalMessage;
 import org.session.libsignal.libsignal.protocol.SignalMessage;
@@ -197,14 +196,6 @@ public class SealedSessionCipher {
     switch (message.getType()) {
       case CiphertextMessage.WHISPER_TYPE: return new SessionCipher(signalProtocolStore, sender).decrypt(new SignalMessage(message.getContent()));
       case CiphertextMessage.PREKEY_TYPE:  return new SessionCipher(signalProtocolStore, sender).decrypt(new PreKeySignalMessage(message.getContent()));
-      case CiphertextMessage.FALLBACK_MESSAGE_TYPE: {
-          try {
-              byte[] privateKey = signalProtocolStore.getIdentityKeyPair().getPrivateKey().serialize();
-              return new FallbackSessionCipher(privateKey, sender.getName()).decrypt(message.getContent());
-          } catch (Exception e) {
-              throw new InvalidMessageException("Failed to decrypt fallback message.");
-          }
-      }
       default: throw new InvalidMessageException("Unknown type: " + message.getType());
     }
   }

libsignal/src/main/java/org/session/libsignal/service/loki/api/DotNetAPI.kt

@@ -9,7 +9,7 @@ import okhttp3.MultipartBody
 import okhttp3.Request
 import okhttp3.RequestBody
 import org.session.libsignal.utilities.logging.Log
-import org.session.libsignal.libsignal.loki.DiffieHellman
+import org.session.libsignal.utilities.DiffieHellman
 import org.session.libsignal.service.api.crypto.ProfileCipherOutputStream
 import org.session.libsignal.service.api.push.exceptions.NonSuccessfulResponseCodeException
 import org.session.libsignal.service.api.push.exceptions.PushNetworkException

libsignal/src/main/java/org/session/libsignal/utilities/DiffieHellman.kt

@@ -1,4 +1,4 @@
-package org.session.libsignal.libsignal.loki
+package org.session.libsignal.utilities
 
 import org.whispersystems.curve25519.Curve25519
 import org.session.libsignal.service.internal.util.Util