From ff391a8af3626787e437d4c5265bdcef187ea8c7 Mon Sep 17 00:00:00 2001
From: parham saremi <45370204+parhamsaremi@users.noreply.github.com>
Date: Fri, 11 Nov 2022 18:40:16 +0330
Subject: [PATCH] Network: return exception when addresses is empty (#50)

This fix is necessary for fixing [1].

[1] https://github.com/nblockchain/geewallet/issues/186
---
 NOnion/Network/TorGuard.fs | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/NOnion/Network/TorGuard.fs b/NOnion/Network/TorGuard.fs
index 33bf4a45..4ffb5834 100644
--- a/NOnion/Network/TorGuard.fs
+++ b/NOnion/Network/TorGuard.fs
@@ -356,16 +356,25 @@ type TorGuard private (client: TcpClient, sslStream: SslStream) =
             //TODO: Client authentication isn't implemented yet!
             do! self.ReceiveExpected<CellAuthChallenge>() |> Async.Ignore
             let! netInfo = self.ReceiveExpected<CellNetInfo>()
+            let maybeOtherAddress = netInfo.MyAddresses |> Seq.tryHead
 
-            do!
-                self.Send
-                    Constants.DefaultCircuitId
-                    {
-                        CellNetInfo.Time =
-                            DateTimeUtils.ToUnixTimestamp DateTime.UtcNow
-                        OtherAddress = netInfo.MyAddresses |> Seq.head
-                        MyAddresses = List.singleton netInfo.OtherAddress
-                    }
+            match maybeOtherAddress with
+            | None ->
+                return
+                    raise
+                    <| GuardConnectionFailedException(
+                        "TorGuard.Handshake: problem in initializing the handshake process"
+                    )
+            | Some otherAddress ->
+                do!
+                    self.Send
+                        Constants.DefaultCircuitId
+                        {
+                            CellNetInfo.Time =
+                                DateTimeUtils.ToUnixTimestamp DateTime.UtcNow
+                            OtherAddress = otherAddress
+                            MyAddresses = List.singleton netInfo.OtherAddress
+                        }
 
             TorLogger.Log "TorGuard: finished handshake process"
         //TODO: do security checks on handshake data