From f9cb740e8d3d54f1b4ab61fe8d7aed684db820f5 Mon Sep 17 00:00:00 2001
From: Paul Higinbotham <paulhi@microsoft.com>
Date: Tue, 6 Apr 2021 12:32:16 -0700
Subject: [PATCH 01/22] Fix SSH remoting connection hang with misconfigured
 endpoint

---
 .../fanin/OutOfProcTransportManager.cs        | 114 +++++++++++++-----
 .../resources/RemotingErrorIdStrings.resx     |   3 +
 2 files changed, 87 insertions(+), 30 deletions(-)

diff --git a/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs b/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
index b8f6da13c17..be3aefd84db 100644
--- a/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
+++ b/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
@@ -635,30 +635,7 @@ internal override void Dispose(bool isDisposing)
             {
                 _cmdTransportManagers.Clear();
                 _closeTimeOutTimer.Dispose();
-
-                // Stop session processing thread.
-                try
-                {
-                    _sessionMessageQueue.CompleteAdding();
-                }
-                catch (ObjectDisposedException)
-                {
-                    // Object already disposed.
-                }
-
-                _sessionMessageQueue.Dispose();
-
-                // Stop command processing thread.
-                try
-                {
-                    _commandMessageQueue.CompleteAdding();
-                }
-                catch (ObjectDisposedException)
-                {
-                    // Object already disposed.
-                }
-
-                _commandMessageQueue.Dispose();
+                DisposeMessageQueue();
             }
         }
 
@@ -1055,6 +1032,37 @@ internal void OnCloseTimeOutTimerElapsed(object source)
         }
 
         #endregion
+    
+        #region Protected Methods
+
+        protected void DisposeMessageQueue()
+        {
+            // Stop session processing thread.
+            try
+            {
+                _sessionMessageQueue.CompleteAdding();
+            }
+            catch (ObjectDisposedException)
+            {
+                // Object already disposed.
+            }
+
+            _sessionMessageQueue.Dispose();
+
+            // Stop command processing thread.
+            try
+            {
+                _commandMessageQueue.CompleteAdding();
+            }
+            catch (ObjectDisposedException)
+            {
+                // Object already disposed.
+            }
+
+            _commandMessageQueue.Dispose();
+        }
+
+        #endregion
     }
 
     internal class OutOfProcessClientSessionTransportManager : OutOfProcessClientSessionTransportManagerBase
@@ -1584,6 +1592,7 @@ internal sealed class SSHClientSessionTransportManager : OutOfProcessClientSessi
         private StreamReader _stdOutReader;
         private StreamReader _stdErrReader;
         private bool _connectionEstablished;
+        private Timer _sshProcessTimer;
 
         private const string _threadName = "SSHTransport Reader Thread";
 
@@ -1641,6 +1650,43 @@ internal override void CreateAsync()
 
             // Create reader thread and send first PSRP message.
             StartReaderThread(_stdOutReader);
+
+            // Monitor SSH process until connection is established.
+            _sshProcessTimer = new Timer(
+                callback: (_) =>
+                {
+                    if (_connectionEstablished)
+                    {
+                        // Monitor no longer needed.
+                        _sshProcessTimer?.Change(Timeout.Infinite, Timeout.Infinite);
+                        return;
+                    }
+
+                    bool sshTerminated = false;
+                    try
+                    {
+                        // Detect if SSH client process terminates prematurely.
+                        using (var sshProcess = System.Diagnostics.Process.GetProcessById(_sshProcessId))
+                        {
+                            sshTerminated = sshProcess == null || sshProcess.Handle == IntPtr.Zero || sshProcess.HasExited;
+                        }
+                    }
+                    catch
+                    {
+                        sshTerminated = true;
+                    }
+
+                    if (sshTerminated)
+                    {
+                        _sshProcessTimer?.Change(Timeout.Infinite, Timeout.Infinite);
+                        _sshProcessId = 0;
+                        HandleSSHError(
+                            new PSRemotingTransportException(RemotingErrorIdStrings.SSHClientCannotConnect));
+                    }
+                },
+                state: null,
+                dueTime: 100,   // 100 mSec
+                period: 100);   // Repeat indefinitely
         }
 
         internal override void CloseAsync()
@@ -1660,14 +1706,20 @@ internal override void CloseAsync()
 
         private void CloseConnection()
         {
+            // Ensure message queue is disposed.
+            base.DisposeMessageQueue();
+
+            var sshProcessTimer = Interlocked.Exchange(ref _sshProcessTimer, null);
+            sshProcessTimer?.Dispose();
+
             var stdInWriter = Interlocked.Exchange(ref _stdInWriter, null);
-            if (stdInWriter != null) { stdInWriter.Dispose(); }
+            stdInWriter?.Dispose();
 
             var stdOutReader = Interlocked.Exchange(ref _stdOutReader, null);
-            if (stdOutReader != null) { stdOutReader.Dispose(); }
+            stdOutReader?.Dispose();
 
             var stdErrReader = Interlocked.Exchange(ref _stdErrReader, null);
-            if (stdErrReader != null) { stdErrReader.Dispose(); }
+            stdErrReader?.Dispose();
 
             // The CloseConnection() method can be called multiple times from multiple places.
             // Set the _sshProcessId to zero here so that we go through the work of finding
@@ -1677,10 +1729,12 @@ private void CloseConnection()
             {
                 try
                 {
-                    var sshProcess = System.Diagnostics.Process.GetProcessById(sshProcessId);
-                    if ((sshProcess != null) && (sshProcess.Handle != IntPtr.Zero) && !sshProcess.HasExited)
+                    using (var sshProcess = System.Diagnostics.Process.GetProcessById(sshProcessId))
                     {
-                        sshProcess.Kill();
+                        if ((sshProcess != null) && (sshProcess.Handle != IntPtr.Zero) && !sshProcess.HasExited)
+                        {
+                            sshProcess.Kill();
+                        }
                     }
                 }
                 catch (ArgumentException) { }
diff --git a/src/System.Management.Automation/resources/RemotingErrorIdStrings.resx b/src/System.Management.Automation/resources/RemotingErrorIdStrings.resx
index b4f9dc40a89..9af92df73df 100644
--- a/src/System.Management.Automation/resources/RemotingErrorIdStrings.resx
+++ b/src/System.Management.Automation/resources/RemotingErrorIdStrings.resx
@@ -1625,6 +1625,9 @@ All WinRM sessions connected to PowerShell session configurations, such as Micro
   <data name="SSHClientEndWithErrorMessage" xml:space="preserve">
     <value>The SSH client session has ended with error message: {0}</value>
   </data>
+  <data name="SSHClientCannotConnect" xml:space="preserve">
+    <value>The SSH client cannot connect to the target. This may be because the target endpoint 'sshd_config' file is misconfigured.</value>
+  </data>
   <data name="MissingRequiredSSHParameter" xml:space="preserve">
     <value>The provided SSHConnection hashtable is missing the required ComputerName or HostName parameter.</value>
   </data>

From 25a3ac767e25991552a3b2ea4df0c37dce30e23b Mon Sep 17 00:00:00 2001
From: Paul Higinbotham <paulhi@microsoft.com>
Date: Fri, 9 Apr 2021 11:07:14 -0700
Subject: [PATCH 02/22] Add support for SSH connection attempt timeout

---
 .../remoting/commands/InvokeCommandCommand.cs |  24 +++
 .../remoting/commands/PSRemotingCmdlet.cs     |  37 ++--
 .../remoting/commands/PushRunspaceCommand.cs  |   2 +-
 .../remoting/commands/newrunspacecommand.cs   |   6 +-
 .../remoting/common/RunspaceConnectionInfo.cs |  79 +++++---
 .../fanin/OutOfProcTransportManager.cs        |  34 ++--
 .../resources/RemotingErrorIdStrings.resx     |   7 +-
 test/SSHRemoting/SSHRemoting.Basic.Tests.ps1  | 172 ++++++++++++++++--
 8 files changed, 287 insertions(+), 74 deletions(-)

diff --git a/src/System.Management.Automation/engine/remoting/commands/InvokeCommandCommand.cs b/src/System.Management.Automation/engine/remoting/commands/InvokeCommandCommand.cs
index b60f3131f24..c86f7903a1a 100644
--- a/src/System.Management.Automation/engine/remoting/commands/InvokeCommandCommand.cs
+++ b/src/System.Management.Automation/engine/remoting/commands/InvokeCommandCommand.cs
@@ -737,6 +737,30 @@ public override string KeyFilePath
             set { base.KeyFilePath = value; }
         }
 
+        /// <summary>
+        /// Gets and sets a value for the SSH subsystem to use for the remote connection.
+        /// </summary>
+        [Parameter(ParameterSetName = InvokeCommandCommand.SSHHostParameterSet)]
+        [Parameter(ParameterSetName = InvokeCommandCommand.FilePathSSHHostParameterSet)]
+        public override string Subsystem
+        {
+            get { return base.Subsystem; }
+
+            set { base.Subsystem = value; }
+        }
+
+        /// <summary>
+        /// Gets and sets a value in milliseconds that limits the time allowed for an SSH connection to be established.
+        /// </summary>
+        [Parameter(ParameterSetName = InvokeCommandCommand.SSHHostParameterSet)]
+        [Parameter(ParameterSetName = InvokeCommandCommand.FilePathSSHHostParameterSet)]
+        public override int ConnectingTimeout
+        {
+            get { return base.ConnectingTimeout; }
+            
+            set { base.ConnectingTimeout = value; }
+        }
+
         /// <summary>
         /// This parameter specifies that SSH is used to establish the remote
         /// connection and act as the remoting transport.  By default WinRM is used
diff --git a/src/System.Management.Automation/engine/remoting/commands/PSRemotingCmdlet.cs b/src/System.Management.Automation/engine/remoting/commands/PSRemotingCmdlet.cs
index 9fafd34eec4..9a6082d1012 100644
--- a/src/System.Management.Automation/engine/remoting/commands/PSRemotingCmdlet.cs
+++ b/src/System.Management.Automation/engine/remoting/commands/PSRemotingCmdlet.cs
@@ -285,6 +285,7 @@ internal struct SSHConnection
         public string KeyFilePath;
         public int Port;
         public string Subsystem;
+        public int ConnectingTimeout;
     }
 
     /// <summary>
@@ -761,6 +762,19 @@ public virtual string KeyFilePath
             set;
         }
 
+        /// <summary>
+        /// Gets and sets a value for the SSH subsystem to use for the remote connection.
+        /// </summary>
+        [Parameter(ValueFromPipelineByPropertyName = true,
+                   ParameterSetName = PSRemotingBaseCmdlet.SSHHostParameterSet)]
+        public virtual string Subsystem { get; set; }
+
+        /// <summary>
+        /// Gets and sets a value in milliseconds that limits the time allowed for an SSH connection to be established.
+        /// </summary>
+        [Parameter(ParameterSetName = PSRemotingBaseCmdlet.SSHHostParameterSet)]
+        public virtual int ConnectingTimeout { get; set; } = -1;    // No timeout by default
+
         /// <summary>
         /// This parameter specifies that SSH is used to establish the remote
         /// connection and act as the remoting transport.  By default WinRM is used
@@ -789,13 +803,6 @@ public virtual Hashtable[] SSHConnection
             set;
         }
 
-        /// <summary>
-        /// This parameter specifies the SSH subsystem to use for the remote connection.
-        /// </summary>
-        [Parameter(ValueFromPipelineByPropertyName = true,
-                   ParameterSetName = InvokeCommandCommand.SSHHostParameterSet)]
-        public virtual string Subsystem { get; set; }
-
         #endregion
 
         #endregion Properties
@@ -856,6 +863,7 @@ internal static void ValidateSpecifiedAuthentication(PSCredential credential, st
         private const string IdentityFilePathAlias = "IdentityFilePath";
         private const string PortParameter = "Port";
         private const string SubsystemParameter = "Subsystem";
+        private const string ConnectingTimeoutParameter = "ConnectingTimeout";
 
         #endregion
 
@@ -902,7 +910,7 @@ protected void ParseSshHostName(string hostname, out string host, out string use
         /// <returns>Array of SSHConnection objects.</returns>
         internal SSHConnection[] ParseSSHConnectionHashTable()
         {
-            List<SSHConnection> connections = new List<SSHConnection>();
+            var connections = new List<SSHConnection>();
             foreach (var item in this.SSHConnection)
             {
                 if (item.ContainsKey(ComputerNameParameter) && item.ContainsKey(HostNameAlias))
@@ -915,7 +923,7 @@ internal SSHConnection[] ParseSSHConnectionHashTable()
                     throw new PSArgumentException(RemotingErrorIdStrings.SSHConnectionDuplicateKeyPath);
                 }
 
-                SSHConnection connectionInfo = new SSHConnection();
+                var connectionInfo = new SSHConnection();
                 foreach (var key in item.Keys)
                 {
                     string paramName = key as string;
@@ -955,6 +963,10 @@ internal SSHConnection[] ParseSSHConnectionHashTable()
                     {
                         connectionInfo.Subsystem = GetSSHConnectionStringParameter(item[paramName]);
                     }
+                    else if (paramName.Equals(ConnectingTimeoutParameter, StringComparison.OrdinalIgnoreCase))
+                    {
+                        connectionInfo.ConnectingTimeout = GetSSHConnectionIntParameter(item[paramName]);
+                    }
                     else
                     {
                         throw new PSArgumentException(
@@ -1448,9 +1460,9 @@ protected void CreateHelpersForSpecifiedSSHComputerNames()
             {
                 ParseSshHostName(computerName, out string host, out string userName, out int port);
 
-                var sshConnectionInfo = new SSHConnectionInfo(userName, host, this.KeyFilePath, port, this.Subsystem);
+                var sshConnectionInfo = new SSHConnectionInfo(userName, host, KeyFilePath, port, Subsystem, ConnectingTimeout);
                 var typeTable = TypeTable.LoadDefaultTypeFiles();
-                var remoteRunspace = RunspaceFactory.CreateRunspace(sshConnectionInfo, this.Host, typeTable) as RemoteRunspace;
+                var remoteRunspace = RunspaceFactory.CreateRunspace(sshConnectionInfo, Host, typeTable) as RemoteRunspace;
                 var pipeline = CreatePipeline(remoteRunspace);
 
                 var operation = new ExecutionCmdletHelperComputerName(remoteRunspace, pipeline);
@@ -1471,7 +1483,8 @@ protected void CreateHelpersForSpecifiedSSHHashComputerNames()
                     sshConnection.ComputerName,
                     sshConnection.KeyFilePath,
                     sshConnection.Port,
-                    sshConnection.Subsystem);
+                    sshConnection.Subsystem,
+                    sshConnection.ConnectingTimeout);
                 var typeTable = TypeTable.LoadDefaultTypeFiles();
                 var remoteRunspace = RunspaceFactory.CreateRunspace(sshConnectionInfo, this.Host, typeTable) as RemoteRunspace;
                 var pipeline = CreatePipeline(remoteRunspace);
diff --git a/src/System.Management.Automation/engine/remoting/commands/PushRunspaceCommand.cs b/src/System.Management.Automation/engine/remoting/commands/PushRunspaceCommand.cs
index cbc5f82742b..996b043d77e 100644
--- a/src/System.Management.Automation/engine/remoting/commands/PushRunspaceCommand.cs
+++ b/src/System.Management.Automation/engine/remoting/commands/PushRunspaceCommand.cs
@@ -1262,7 +1262,7 @@ private RemoteRunspace GetRunspaceForContainerSession()
         private RemoteRunspace GetRunspaceForSSHSession()
         {
             ParseSshHostName(HostName, out string host, out string userName, out int port);
-            var sshConnectionInfo = new SSHConnectionInfo(userName, host, this.KeyFilePath, port, this.Subsystem);
+            var sshConnectionInfo = new SSHConnectionInfo(userName, host, KeyFilePath, port, Subsystem, ConnectingTimeout);
             var typeTable = TypeTable.LoadDefaultTypeFiles();
 
             // Use the class _tempRunspace field while the runspace is being opened so that StopProcessing can be handled at that time.
diff --git a/src/System.Management.Automation/engine/remoting/commands/newrunspacecommand.cs b/src/System.Management.Automation/engine/remoting/commands/newrunspacecommand.cs
index 625bb86fd64..d4a0a3e7508 100644
--- a/src/System.Management.Automation/engine/remoting/commands/newrunspacecommand.cs
+++ b/src/System.Management.Automation/engine/remoting/commands/newrunspacecommand.cs
@@ -1092,7 +1092,8 @@ private List<RemoteRunspace> CreateRunspacesForSSHHostParameterSet()
                     host,
                     this.KeyFilePath,
                     port,
-                    Subsystem);
+                    Subsystem,
+                    ConnectingTimeout);
                 var typeTable = TypeTable.LoadDefaultTypeFiles();
                 string rsName = GetRunspaceName(index, out int rsIdUnused);
                 index++;
@@ -1118,7 +1119,8 @@ private List<RemoteRunspace> CreateRunspacesForSSHHostHashParameterSet()
                     sshConnection.ComputerName,
                     sshConnection.KeyFilePath,
                     sshConnection.Port,
-                    sshConnection.Subsystem);
+                    sshConnection.Subsystem,
+                    sshConnection.ConnectingTimeout);
                 var typeTable = TypeTable.LoadDefaultTypeFiles();
                 string rsName = GetRunspaceName(index, out int rsIdUnused);
                 index++;
diff --git a/src/System.Management.Automation/engine/remoting/common/RunspaceConnectionInfo.cs b/src/System.Management.Automation/engine/remoting/common/RunspaceConnectionInfo.cs
index ea8a9c1a9d0..b0a88eebe9b 100644
--- a/src/System.Management.Automation/engine/remoting/common/RunspaceConnectionInfo.cs
+++ b/src/System.Management.Automation/engine/remoting/common/RunspaceConnectionInfo.cs
@@ -1907,6 +1907,16 @@ internal override BaseClientSessionTransportManager CreateClientSessionTransport
     /// </summary>
     public sealed class SSHConnectionInfo : RunspaceConnectionInfo
     {
+        #region Constants
+
+        /// <summary>
+        /// Default value for subsystem.
+        /// </summary>
+        private const string DefaultSubsystem = "powershell";
+        private const int DefaultConnectingTimeoutTime = -1;    // Never time out
+
+        #endregion
+
         #region Properties
 
         /// <summary>
@@ -1945,6 +1955,16 @@ private string Subsystem
             set;
         }
 
+        /// <summary>
+        /// Gets or sets a time in milliseconds after which a connection attempt is terminated.
+        /// Default value (-1) never times out and a connection attempt waits indefinitely.
+        /// </summary>
+        public int ConnectingTimeout
+        {
+            get;
+            set;
+        }
+
         #endregion
 
         #region Constructors
@@ -1968,11 +1988,12 @@ public SSHConnectionInfo(
         {
             if (computerName == null) { throw new PSArgumentNullException(nameof(computerName)); }
 
-            this.UserName = userName;
-            this.ComputerName = computerName;
-            this.KeyFilePath = keyFilePath;
-            this.Port = 0;
-            this.Subsystem = DefaultSubsystem;
+            UserName = userName;
+            ComputerName = computerName;
+            KeyFilePath = keyFilePath;
+            Port = 0;
+            Subsystem = DefaultSubsystem;
+            ConnectingTimeout = DefaultConnectingTimeoutTime;
         }
 
         /// <summary>
@@ -1989,8 +2010,7 @@ public SSHConnectionInfo(
             int port) : this(userName, computerName, keyFilePath)
         {
             ValidatePortInRange(port);
-
-            this.Port = port;
+            Port = port;
         }
 
         /// <summary>
@@ -2006,12 +2026,29 @@ public SSHConnectionInfo(
             string computerName,
             string keyFilePath,
             int port,
-            string subsystem) : this(userName, computerName, keyFilePath)
+            string subsystem) : this(userName, computerName, keyFilePath, port)
         {
-            ValidatePortInRange(port);
+            Subsystem = (string.IsNullOrEmpty(subsystem)) ? DefaultSubsystem : subsystem;
+        }
 
-            this.Port = port;
-            this.Subsystem = (string.IsNullOrEmpty(subsystem)) ? DefaultSubsystem : subsystem;
+        /// <summary>
+        /// Constructor.
+        /// </summary>
+        /// <param name="userName">User Name.</param>
+        /// <param name="computerName">Computer Name.</param>
+        /// <param name="keyFilePath">Key File Path.</param>
+        /// <param name="port">Port number for connection (default 22).</param>
+        /// <param name="subsystem">Subsystem to use (default 'powershell').</param>
+        /// <param name="connectingTimeout">Timeout time for terminating connection attempt.</param>
+        public SSHConnectionInfo(
+            string userName,
+            string computerName,
+            string keyFilePath,
+            int port,
+            string subsystem,
+            int connectingTimeout) : this(userName, computerName, keyFilePath, port, subsystem)
+        {
+            ConnectingTimeout = connectingTimeout;
         }
 
         #endregion
@@ -2064,11 +2101,12 @@ public override string CertificateThumbprint
         internal override RunspaceConnectionInfo InternalCopy()
         {
             SSHConnectionInfo newCopy = new SSHConnectionInfo();
-            newCopy.ComputerName = this.ComputerName;
-            newCopy.UserName = this.UserName;
-            newCopy.KeyFilePath = this.KeyFilePath;
-            newCopy.Port = this.Port;
-            newCopy.Subsystem = this.Subsystem;
+            newCopy.ComputerName = ComputerName;
+            newCopy.UserName = UserName;
+            newCopy.KeyFilePath = KeyFilePath;
+            newCopy.Port = Port;
+            newCopy.Subsystem = Subsystem;
+            newCopy.ConnectingTimeout = ConnectingTimeout;
 
             return newCopy;
         }
@@ -2187,15 +2225,6 @@ internal int StartSSHProcess(
 
         #endregion
 
-        #region Constants
-
-        /// <summary>
-        /// Default value for subsystem.
-        /// </summary>
-        private const string DefaultSubsystem = "powershell";
-
-        #endregion
-
         #region SSH Process Creation
 
 #if UNIX
diff --git a/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs b/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
index be3aefd84db..e698d831b6e 100644
--- a/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
+++ b/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
@@ -1592,7 +1592,7 @@ internal sealed class SSHClientSessionTransportManager : OutOfProcessClientSessi
         private StreamReader _stdOutReader;
         private StreamReader _stdErrReader;
         private bool _connectionEstablished;
-        private Timer _sshProcessTimer;
+        private Timer _connectionTimer;
 
         private const string _threadName = "SSHTransport Reader Thread";
 
@@ -1651,21 +1651,24 @@ internal override void CreateAsync()
             // Create reader thread and send first PSRP message.
             StartReaderThread(_stdOutReader);
 
-            // Monitor SSH process until connection is established.
-            _sshProcessTimer = new Timer(
-                callback: (_) =>
+            if (_connectionInfo.ConnectingTimeout < 0)
+            {
+                return;
+            }
+
+            // Start connection timeout timer if requested.
+            _connectionTimer = new Timer(
+                callback: (_) => 
                 {
                     if (_connectionEstablished)
                     {
-                        // Monitor no longer needed.
-                        _sshProcessTimer?.Change(Timeout.Infinite, Timeout.Infinite);
                         return;
                     }
 
+                    // Detect if SSH client process terminates prematurely.
                     bool sshTerminated = false;
                     try
                     {
-                        // Detect if SSH client process terminates prematurely.
                         using (var sshProcess = System.Diagnostics.Process.GetProcessById(_sshProcessId))
                         {
                             sshTerminated = sshProcess == null || sshProcess.Handle == IntPtr.Zero || sshProcess.HasExited;
@@ -1676,17 +1679,18 @@ internal override void CreateAsync()
                         sshTerminated = true;
                     }
 
+                    var errorMessage = StringUtil.Format(RemotingErrorIdStrings.SSHClientConnectTimeout, _connectionInfo.ConnectingTimeout / 1000);
                     if (sshTerminated)
                     {
-                        _sshProcessTimer?.Change(Timeout.Infinite, Timeout.Infinite);
-                        _sshProcessId = 0;
-                        HandleSSHError(
-                            new PSRemotingTransportException(RemotingErrorIdStrings.SSHClientCannotConnect));
+                        errorMessage += "\n" + RemotingErrorIdStrings.SSHClientConnectProcessTerminated;
                     }
+
+                    HandleSSHError(
+                        new PSRemotingTransportException(errorMessage));
                 },
                 state: null,
-                dueTime: 100,   // 100 mSec
-                period: 100);   // Repeat indefinitely
+                dueTime: _connectionInfo.ConnectingTimeout,
+                period: Timeout.Infinite);
         }
 
         internal override void CloseAsync()
@@ -1709,8 +1713,8 @@ private void CloseConnection()
             // Ensure message queue is disposed.
             base.DisposeMessageQueue();
 
-            var sshProcessTimer = Interlocked.Exchange(ref _sshProcessTimer, null);
-            sshProcessTimer?.Dispose();
+            var connectionTimer = Interlocked.Exchange(ref _connectionTimer, null);
+            connectionTimer?.Dispose();
 
             var stdInWriter = Interlocked.Exchange(ref _stdInWriter, null);
             stdInWriter?.Dispose();
diff --git a/src/System.Management.Automation/resources/RemotingErrorIdStrings.resx b/src/System.Management.Automation/resources/RemotingErrorIdStrings.resx
index 9af92df73df..664033e20bd 100644
--- a/src/System.Management.Automation/resources/RemotingErrorIdStrings.resx
+++ b/src/System.Management.Automation/resources/RemotingErrorIdStrings.resx
@@ -1625,8 +1625,11 @@ All WinRM sessions connected to PowerShell session configurations, such as Micro
   <data name="SSHClientEndWithErrorMessage" xml:space="preserve">
     <value>The SSH client session has ended with error message: {0}</value>
   </data>
-  <data name="SSHClientCannotConnect" xml:space="preserve">
-    <value>The SSH client cannot connect to the target. This may be because the target endpoint 'sshd_config' file is misconfigured.</value>
+  <data name="SSHClientConnectTimeout" xml:space="preserve">
+    <value>SSH connection attempt failed after time out: {0} seconds.</value>
+  </data>
+  <data name="SSHClientConnectProcessTerminated" xml:space="preserve">
+    <value>SSH client process terminated before connection could be established.</value>
   </data>
   <data name="MissingRequiredSSHParameter" xml:space="preserve">
     <value>The provided SSHConnection hashtable is missing the required ComputerName or HostName parameter.</value>
diff --git a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1 b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
index 40fa0ec1027..c6dfa286ab5 100644
--- a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
+++ b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
@@ -6,6 +6,107 @@ Describe "SSHRemoting Basic Tests" -tags CI {
     # SSH remoting is set up to automatically authenticate current user via SSH keys
     # All tests connect back to localhost machine
 
+    $script:TestConnectingTimeout = 5000    # Milliseconds
+
+    function CheckSSHDService
+    {
+        if ($IsWindows)
+        {
+            Write-Verbose -Verbose "Restarting Windows SSHD service..."
+            Restart-Service sshd
+            Write-Verbose -Verbose "SSHD service status: $(Get-Service sshd | Out-String)"
+        }
+        else
+        {
+            Write-Verbose -Verbose "Restarting Linux SSHD service..."
+            sudo service ssh restart
+            $status = sudo service ssh status
+            Write-Verbose -Verbose "SSHD service status: $status"
+        }
+    }
+
+    function TryNewPSSession
+    {
+        param(
+            [string[]] $HostName,
+            [string[]] $Name,
+            [int] $Port,
+            [string] $UserName,
+            [string] $KeyFilePath,
+            [string] $Subsystem
+        )
+
+        # Try creating a new SSH connection
+        $timeout = $script:TestConnectingTimeout
+        $connectionError = $null
+        $session = $null
+        $count = 0
+        while (($null -eq $session) -and ($count++ -lt 2))
+        {
+            $session = New-PSSession @PSBoundParameters -ConnectingTimeout $timeout -ErrorVariable connectionError -ErrorAction SilentlyContinue
+            if ($null -eq $session)
+            {
+                Write-Verbose -Verbose "SSH New-PSSession remoting connect failed after $($timeout/1000) second wait."
+
+                if ($count -eq 1)
+                {
+                    # Try restarting sshd service
+                    CheckSSHDService
+                }
+            }
+        }
+
+        if ($null -eq $session)
+        {
+            $message = "New-PSSession unable to connect to SSH remoting endpoint after two attempts. Error: $($connectionError.Exception.Message)"
+            throw [System.Management.Automation.PSInvalidOperationException]::new($message)
+        }
+
+        Write-Verbose -Verbose "SSH New-PSSession remoting connect succeeded."
+        Write-Output $session
+    }
+
+    function TryNewPSSessionHash
+    {
+        param (
+            [hashtable[]] $SSHConnection,
+            [string[]] $Name
+        )
+
+        foreach ($connect in $SSHConnection)
+        {
+            $connect.Add('ConnectingTimeout', $script:TestConnectingTimeout)
+        }
+
+        # Try creating a new SSH connection
+        $connectionError = $null
+        $session = $null
+        $count = 0
+        while (($null -eq $session) -and ($count++ -lt 2))
+        {
+            $session = New-PSSession @PSBoundParameters -ErrorVariable connectionError -ErrorAction SilentlyContinue
+            if ($null -eq $session)
+            {
+                Write-Verbose -Verbose "SSH New-PSSession remoting connect failed after $($timeout/1000) second wait."
+
+                if ($count -eq 1)
+                {
+                    # Try restarting sshd service
+                    CheckSSHDService
+                }
+            }
+        }
+
+        if ($null -eq $session)
+        {
+            $message = "New-PSSession unable to connect to SSH remoting endpoint after two attempts. Error: $($connectionError.Exception.Message)"
+            throw [System.Management.Automation.PSInvalidOperationException]::new($message)
+        }
+
+        Write-Verbose -Verbose "SSH New-PSSession remoting connect succeeded."
+        Write-Output $session
+    }
+
     function VerifySession {
         param (
             [System.Management.Automation.Runspaces.PSSession] $session
@@ -28,37 +129,32 @@ Describe "SSHRemoting Basic Tests" -tags CI {
         }
 
         It "Verifies new connection with implicit current User" {
-            $script:session = New-PSSession -HostName localhost -ErrorVariable err
-            $err | Should -HaveCount 0
+            $script:session = TryNewPSSession -HostName localhost
             VerifySession $script:session
         }
 
         It "Verifies new connection with explicit User parameter" {
-            $script:session = New-PSSession -HostName localhost -UserName (whoami) -ErrorVariable err
-            $err | Should -HaveCount 0
+            $script:session = TryNewPSSession -HostName localhost -UserName (whoami)
             VerifySession $script:session
         }
 
         It "Verifies explicit Name parameter" {
             $sessionName = 'TestSessionNameA'
-            $script:session = New-PSSession -HostName localhost -Name $sessionName -ErrorVariable err
-            $err | Should -HaveCount 0
+            $script:session = TryNewPSSession -HostName localhost -Name $sessionName
             VerifySession $script:session
             $script:session.Name | Should -BeExactly $sessionName
         }
 
         It "Verifies explicit Port parameter" {
             $portNum = 22
-            $script:session = New-PSSession -HostName localhost -Port $portNum -ErrorVariable err
-            $err | Should -HaveCount 0
+            $script:session = TryNewPSSession -HostName localhost -Port $portNum
             VerifySession $script:session
         }
 
         It "Verifies explicit Subsystem parameter" {
             $portNum = 22
             $subSystem = 'powershell'
-            $script:session = New-PSSession -HostName localhost -Port $portNum -SubSystem $subSystem -ErrorVariable err
-            $err | Should -HaveCount 0
+            $script:session = TryNewPSSession -HostName localhost -Port $portNum -SubSystem $subSystem
             VerifySession $script:session
         }
 
@@ -66,8 +162,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             $keyFilePath = "$HOME/.ssh/id_rsa"
             $portNum = 22
             $subSystem = 'powershell'
-            $script:session = New-PSSession -HostName localhost -Port $portNum -SubSystem $subSystem -KeyFilePath $keyFilePath -ErrorVariable err
-            $err | Should -HaveCount 0
+            $script:session = TryNewPSSession -HostName localhost -Port $portNum -SubSystem $subSystem -KeyFilePath $keyFilePath
             VerifySession $script:session
         }
 
@@ -85,8 +180,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
                 KeyFilePath = "$HOME/.ssh/id_rsa"
                 Subsystem = 'powershell'
             })
-            $script:sessions = New-PSSession -SSHConnection $sshConnection -Name 'Connection1','Connection2' -ErrorVariable err
-            $err | Should -HaveCount 0
+            $script:sessions = TryNewPSSessionHash -SSHConnection $sshConnection -Name 'Connection1','Connection2'
             $script:sessions | Should -HaveCount 2
             $script:sessions[0].Name | Should -BeLike 'Connection*'
             $script:sessions[1].Name | Should -BeLike 'Connection*'
@@ -95,6 +189,52 @@ Describe "SSHRemoting Basic Tests" -tags CI {
         }
     }
 
+    function TryCreateRunspace
+    {
+        param (
+            [string] $UserName,
+            [string] $ComputerName,
+            [string] $KeyFilePath,
+            [int] $Port,
+            [string] $Subsystem
+        )
+
+        $timeout = $script:TestConnectingTimeout
+        $connectionError = $null
+        $count = 0
+        $rs = $null
+        $ci = [System.Management.Automation.Runspaces.SSHConnectionInfo]::new($UserName, $ComputerName, $KeyFilePath, $Port, $Subsystem, $timeout)
+        while (($null -eq $rs) -and ($count++ -lt 2))
+        {
+            try
+            {
+                $rs = [runspacefactory]::CreateRunspace($host, $ci)
+                $null = $rs.Open()
+            }
+            catch
+            {
+                $connectionError = $_
+                $rs = $null
+                Write-Verbose -Verbose "SSH Runspace Open remoting connect failed after $($timeout/1000) second wait."
+
+                if ($count -eq 1)
+                {
+                    # Try restarting sshd service
+                    CheckSSHDService
+                }
+            }
+        }
+
+        if ($null -eq $rs)
+        {
+            $message = "Runspace open unable to connect to SSH remoting endpoint after three attempts. Error: $($connectionError.Message)"
+            throw [System.Management.Automation.PSInvalidOperationException]::new($message)
+        }
+
+        Write-Verbose -Verbose "SSH Runspace Open remoting connect succeeded."
+        Write-Output $rs
+    }
+
     function VerifyRunspace {
         param (
             [runspace] $rs
@@ -178,9 +318,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
                 $SubSystem
             )
 
-            $ci = [System.Management.Automation.Runspaces.SSHConnectionInfo]::new($UserName, $ComputerName, $KeyFilePath, $Port, $Subsystem)
-            $script:rs = [runspacefactory]::CreateRunspace($host, $ci)
-            $script:rs.Open()
+            $script:rs = TryCreateRunspace -UserName $UserName -ComputerName $ComputerName -KeyFilePath $KeyFilePath -Port $Port -Subsystem $Subsystem
             VerifyRunspace $script:rs
         }
     }

From bf1a6a8b8cdcb04e77bd65b2144fcd3be16410f8 Mon Sep 17 00:00:00 2001
From: Paul Higinbotham <paulhi@microsoft.com>
Date: Fri, 9 Apr 2021 11:17:24 -0700
Subject: [PATCH 03/22] Fix CodeFactor issues

---
 .../engine/remoting/commands/PSRemotingCmdlet.cs          | 4 ++--
 .../engine/remoting/common/RunspaceConnectionInfo.cs      | 8 ++++----
 .../engine/remoting/fanin/OutOfProcTransportManager.cs    | 2 +-
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/System.Management.Automation/engine/remoting/commands/PSRemotingCmdlet.cs b/src/System.Management.Automation/engine/remoting/commands/PSRemotingCmdlet.cs
index 9a6082d1012..840b6c301d7 100644
--- a/src/System.Management.Automation/engine/remoting/commands/PSRemotingCmdlet.cs
+++ b/src/System.Management.Automation/engine/remoting/commands/PSRemotingCmdlet.cs
@@ -763,14 +763,14 @@ public virtual string KeyFilePath
         }
 
         /// <summary>
-        /// Gets and sets a value for the SSH subsystem to use for the remote connection.
+        /// Gets or sets a value for the SSH subsystem to use for the remote connection.
         /// </summary>
         [Parameter(ValueFromPipelineByPropertyName = true,
                    ParameterSetName = PSRemotingBaseCmdlet.SSHHostParameterSet)]
         public virtual string Subsystem { get; set; }
 
         /// <summary>
-        /// Gets and sets a value in milliseconds that limits the time allowed for an SSH connection to be established.
+        /// Gets or sets a value in milliseconds that limits the time allowed for an SSH connection to be established.
         /// </summary>
         [Parameter(ParameterSetName = PSRemotingBaseCmdlet.SSHHostParameterSet)]
         public virtual int ConnectingTimeout { get; set; } = -1;    // No timeout by default
diff --git a/src/System.Management.Automation/engine/remoting/common/RunspaceConnectionInfo.cs b/src/System.Management.Automation/engine/remoting/common/RunspaceConnectionInfo.cs
index b0a88eebe9b..77c4592dba7 100644
--- a/src/System.Management.Automation/engine/remoting/common/RunspaceConnectionInfo.cs
+++ b/src/System.Management.Automation/engine/remoting/common/RunspaceConnectionInfo.cs
@@ -2032,11 +2032,11 @@ public SSHConnectionInfo(
         }
 
         /// <summary>
-        /// Constructor.
+        /// Initializes a new instance of SSHConnectionInfo.
         /// </summary>
-        /// <param name="userName">User Name.</param>
-        /// <param name="computerName">Computer Name.</param>
-        /// <param name="keyFilePath">Key File Path.</param>
+        /// <param name="userName">Name of user.</param>
+        /// <param name="computerName">Name of computer.</param>
+        /// <param name="keyFilePath">Path of key file.</param>
         /// <param name="port">Port number for connection (default 22).</param>
         /// <param name="subsystem">Subsystem to use (default 'powershell').</param>
         /// <param name="connectingTimeout">Timeout time for terminating connection attempt.</param>
diff --git a/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs b/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
index e698d831b6e..5b7f3b31c0b 100644
--- a/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
+++ b/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
@@ -1711,7 +1711,7 @@ internal override void CloseAsync()
         private void CloseConnection()
         {
             // Ensure message queue is disposed.
-            base.DisposeMessageQueue();
+            DisposeMessageQueue();
 
             var connectionTimer = Interlocked.Exchange(ref _connectionTimer, null);
             connectionTimer?.Dispose();

From 95c9942dcb66b612dfdaf6c0223d7fed7b16d226 Mon Sep 17 00:00:00 2001
From: Paul Higinbotham <paulhi@microsoft.com>
Date: Fri, 9 Apr 2021 12:26:12 -0700
Subject: [PATCH 04/22] Add Write-Verbose for debugging

---
 test/SSHRemoting/SSHRemoting.Basic.Tests.ps1 | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1 b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
index c6dfa286ab5..ede6ce3ccf3 100644
--- a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
+++ b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
@@ -240,18 +240,22 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             [runspace] $rs
         )
 
+        Write-Verbose -Verbose "VerifyRunspace called for runspace: $($rs.Id)"
+
         $rs.RunspaceStateInfo.State | Should -BeExactly 'Opened'
         $rs.RunspaceAvailability | Should -BeExactly 'Available'
         $rs.RunspaceIsRemote | Should -BeTrue
         $ps = [powershell]::Create()
         try
         {
+            Write-Verbose -Verbose "VerifyRunspace: Invoking PSSenderInfo"
             $ps.Runspace = $rs
             $psRemoteVersion = $ps.AddScript('$PSSenderInfo.ApplicationArguments.PSVersionTable.PSVersion').Invoke()
             $psRemoteVersion.Major | Should -BeExactly $PSVersionTable.PSVersion.Major
             $psRemoteVersion.Minor | Should -BeExactly $PSVersionTable.PSVersion.Minor
 
             $ps.Commands.Clear()
+            Write-Verbose -Verbose "VerifyRunspace: Invoking whoami"
             $ps.AddScript('whoami').Invoke() | Should -BeExactly $(whoami)
         }
         finally

From a4c521eabd2036d1cb744ef4d8a9c7147da59a8e Mon Sep 17 00:00:00 2001
From: Paul Higinbotham <paulhi@microsoft.com>
Date: Fri, 9 Apr 2021 12:39:00 -0700
Subject: [PATCH 05/22] Add more debug info

---
 test/SSHRemoting/SSHRemoting.Basic.Tests.ps1 | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1 b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
index ede6ce3ccf3..4e2d15b94da 100644
--- a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
+++ b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
@@ -112,13 +112,18 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             [System.Management.Automation.Runspaces.PSSession] $session
         )
 
+        Write-Verbose -Verbose "VerifySession called for session: $($session.Id)"
+
         $session.State | Should -BeExactly 'Opened'
         $session.ComputerName | Should -BeExactly 'localhost'
         $session.Transport | Should -BeExactly 'SSH'
+        Write-Verbose -Verbose "Invoking whoami"
         Invoke-Command -Session $session -ScriptBlock { whoami } | Should -BeExactly $(whoami)
+        Write-Verbose -Verbose "Invoking PSSenderInfo"
         $psRemoteVersion = Invoke-Command -Session $session -ScriptBlock { $PSSenderInfo.ApplicationArguments.PSVersionTable.PSVersion }
         $psRemoteVersion.Major | Should -BeExactly $PSVersionTable.PSVersion.Major
         $psRemoteVersion.Minor | Should -BeExactly $PSVersionTable.PSVersion.Minor
+        Write-Verbose -Verbose "VerifySession complete"
     }
 
     Context "New-PSSession Tests" {
@@ -257,6 +262,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             $ps.Commands.Clear()
             Write-Verbose -Verbose "VerifyRunspace: Invoking whoami"
             $ps.AddScript('whoami').Invoke() | Should -BeExactly $(whoami)
+            Write-Verbose -Verbose "VerifyRunspace complete"
         }
         finally
         {

From 50dc46417b8308d7dedcf62bdda796df99875d3e Mon Sep 17 00:00:00 2001
From: Paul Higinbotham <paulhi@microsoft.com>
Date: Fri, 9 Apr 2021 13:12:25 -0700
Subject: [PATCH 06/22] [Feature]


From 853598cf53bc76f9a7e9150aa427ef183815cb1a Mon Sep 17 00:00:00 2001
From: Paul Higinbotham <paulhi@microsoft.com>
Date: Fri, 9 Apr 2021 13:41:58 -0700
Subject: [PATCH 07/22] More debug output

---
 test/SSHRemoting/SSHRemoting.Basic.Tests.ps1 | 27 +++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1 b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
index 4e2d15b94da..bc0b664a799 100644
--- a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
+++ b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
@@ -36,6 +36,8 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             [string] $Subsystem
         )
 
+        Write-Verbose -Verbose "Starting TryNewPSSession ..."
+
         # Try creating a new SSH connection
         $timeout = $script:TestConnectingTimeout
         $connectionError = $null
@@ -73,6 +75,8 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             [string[]] $Name
         )
 
+        Write-Verbose -Verbose "Starting TryNewPSSessionHash ..."
+
         foreach ($connect in $SSHConnection)
         {
             $connect.Add('ConnectingTimeout', $script:TestConnectingTimeout)
@@ -129,49 +133,64 @@ Describe "SSHRemoting Basic Tests" -tags CI {
     Context "New-PSSession Tests" {
 
         AfterEach {
+            Write-Verbose -Verbose "Starting New-PSSession AfterEach"
             if ($script:session -ne $null) { Remove-PSSession -Session $script:session }
             if ($script:sessions -ne $null) { Remove-PSSession -Session $script:sessions }
+            Write-Verbose -Verbose "AfterEach complete"
         }
 
         It "Verifies new connection with implicit current User" {
+            Write-Verbose -Verbose "It Starting: Verifies new connection with implicit current User"
             $script:session = TryNewPSSession -HostName localhost
             VerifySession $script:session
+            Write-Verbose -Verbose "It Complete"
         }
 
         It "Verifies new connection with explicit User parameter" {
+            Write-Verbose -Verbose "It Starting: Verifies new connection with explicit User parameter"
             $script:session = TryNewPSSession -HostName localhost -UserName (whoami)
             VerifySession $script:session
+            Write-Verbose -Verbose "It Complete"
         }
 
         It "Verifies explicit Name parameter" {
+            Write-Verbose -Verbose "It Starting: Verifies explicit Name parameter"
             $sessionName = 'TestSessionNameA'
             $script:session = TryNewPSSession -HostName localhost -Name $sessionName
             VerifySession $script:session
             $script:session.Name | Should -BeExactly $sessionName
+            Write-Verbose -Verbose "It Complete"
         }
 
         It "Verifies explicit Port parameter" {
+            Write-Verbose -Verbose "It Starting: Verifies explicit Port parameter"
             $portNum = 22
             $script:session = TryNewPSSession -HostName localhost -Port $portNum
             VerifySession $script:session
+            Write-Verbose -Verbose "It Complete"
         }
 
         It "Verifies explicit Subsystem parameter" {
+            Write-Verbose -Verbose "It Starting: Verifies explicit Subsystem parameter"
             $portNum = 22
             $subSystem = 'powershell'
             $script:session = TryNewPSSession -HostName localhost -Port $portNum -SubSystem $subSystem
             VerifySession $script:session
+            Write-Verbose -Verbose "It Complete"
         }
 
         It "Verifies explicit KeyFilePath parameter" {
+            Write-Verbose -Verbose "It Starting: Verifies explicit KeyFilePath parameter"
             $keyFilePath = "$HOME/.ssh/id_rsa"
             $portNum = 22
             $subSystem = 'powershell'
             $script:session = TryNewPSSession -HostName localhost -Port $portNum -SubSystem $subSystem -KeyFilePath $keyFilePath
             VerifySession $script:session
+            Write-Verbose -Verbose "It Complete"
         }
 
         It "Verifies SSHConnection hash table parameters" {
+            Write-Verbose -Verbose "It Starting: Verifies SSHConnection hash table parameters"
             $sshConnection = @(
             @{
                 HostName = 'localhost'
@@ -191,6 +210,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             $script:sessions[1].Name | Should -BeLike 'Connection*'
             VerifySession $script:sessions[0]
             VerifySession $script:sessions[1]
+            Write-Verbose -Verbose "It Complete"
         }
     }
 
@@ -204,6 +224,8 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             [string] $Subsystem
         )
 
+        Write-Verbose -Verbose "Starting TryCreateRunspace ..."
+
         $timeout = $script:TestConnectingTimeout
         $connectionError = $null
         $count = 0
@@ -325,11 +347,14 @@ Describe "SSHRemoting Basic Tests" -tags CI {
                 $ComputerName,
                 $KeyFilePath,
                 $Port,
-                $SubSystem
+                $SubSystem,
+                $TestName
             )
 
+            Write-Verbose -Verbose "It Starting: $TestName"
             $script:rs = TryCreateRunspace -UserName $UserName -ComputerName $ComputerName -KeyFilePath $KeyFilePath -Port $Port -Subsystem $Subsystem
             VerifyRunspace $script:rs
+            Write-Verbose -Verbose "It Complete"
         }
     }
 }

From 33f5e505caca7a7d4b67053fe4331b60ddc3b2c4 Mon Sep 17 00:00:00 2001
From: Paul Higinbotham <paulhi@microsoft.com>
Date: Fri, 9 Apr 2021 13:55:32 -0700
Subject: [PATCH 08/22] [Feature]


From 64af989111933fe17e8ef435f0db478010b1dcec Mon Sep 17 00:00:00 2001
From: Paul Higinbotham <paulhi@microsoft.com>
Date: Mon, 12 Apr 2021 09:18:48 -0700
Subject: [PATCH 09/22] Ensure all It blocks have Should

---
 test/SSHRemoting/SSHRemoting.Basic.Tests.ps1 | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1 b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
index bc0b664a799..dc9a8e67cdb 100644
--- a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
+++ b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
@@ -142,6 +142,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
         It "Verifies new connection with implicit current User" {
             Write-Verbose -Verbose "It Starting: Verifies new connection with implicit current User"
             $script:session = TryNewPSSession -HostName localhost
+            $script:session | Should -Not -BeNullOrEmpty
             VerifySession $script:session
             Write-Verbose -Verbose "It Complete"
         }
@@ -149,6 +150,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
         It "Verifies new connection with explicit User parameter" {
             Write-Verbose -Verbose "It Starting: Verifies new connection with explicit User parameter"
             $script:session = TryNewPSSession -HostName localhost -UserName (whoami)
+            $script:session | Should -Not -BeNullOrEmpty
             VerifySession $script:session
             Write-Verbose -Verbose "It Complete"
         }
@@ -157,6 +159,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             Write-Verbose -Verbose "It Starting: Verifies explicit Name parameter"
             $sessionName = 'TestSessionNameA'
             $script:session = TryNewPSSession -HostName localhost -Name $sessionName
+            $script:session | Should -Not -BeNullOrEmpty
             VerifySession $script:session
             $script:session.Name | Should -BeExactly $sessionName
             Write-Verbose -Verbose "It Complete"
@@ -166,6 +169,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             Write-Verbose -Verbose "It Starting: Verifies explicit Port parameter"
             $portNum = 22
             $script:session = TryNewPSSession -HostName localhost -Port $portNum
+            $script:session | Should -Not -BeNullOrEmpty
             VerifySession $script:session
             Write-Verbose -Verbose "It Complete"
         }
@@ -175,6 +179,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             $portNum = 22
             $subSystem = 'powershell'
             $script:session = TryNewPSSession -HostName localhost -Port $portNum -SubSystem $subSystem
+            $script:session | Should -Not -BeNullOrEmpty
             VerifySession $script:session
             Write-Verbose -Verbose "It Complete"
         }
@@ -185,6 +190,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             $portNum = 22
             $subSystem = 'powershell'
             $script:session = TryNewPSSession -HostName localhost -Port $portNum -SubSystem $subSystem -KeyFilePath $keyFilePath
+            $script:session | Should -Not -BeNullOrEmpty
             VerifySession $script:session
             Write-Verbose -Verbose "It Complete"
         }
@@ -205,6 +211,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
                 Subsystem = 'powershell'
             })
             $script:sessions = TryNewPSSessionHash -SSHConnection $sshConnection -Name 'Connection1','Connection2'
+            $script:session | Should -Not -BeNullOrEmpty
             $script:sessions | Should -HaveCount 2
             $script:sessions[0].Name | Should -BeLike 'Connection*'
             $script:sessions[1].Name | Should -BeLike 'Connection*'
@@ -353,6 +360,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
 
             Write-Verbose -Verbose "It Starting: $TestName"
             $script:rs = TryCreateRunspace -UserName $UserName -ComputerName $ComputerName -KeyFilePath $KeyFilePath -Port $Port -Subsystem $Subsystem
+            $script:rs | Should -Not -BeNullOrEmpty
             VerifyRunspace $script:rs
             Write-Verbose -Verbose "It Complete"
         }

From d05e51af0c969d17512c6dfce492c6dbca53d59d Mon Sep 17 00:00:00 2001
From: Paul Higinbotham <paulhi@microsoft.com>
Date: Mon, 12 Apr 2021 09:42:13 -0700
Subject: [PATCH 10/22] Try removing AfterEach

---
 test/SSHRemoting/SSHRemoting.Basic.Tests.ps1 | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1 b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
index dc9a8e67cdb..19c290d52ac 100644
--- a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
+++ b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
@@ -132,12 +132,14 @@ Describe "SSHRemoting Basic Tests" -tags CI {
 
     Context "New-PSSession Tests" {
 
+        <#
         AfterEach {
             Write-Verbose -Verbose "Starting New-PSSession AfterEach"
             if ($script:session -ne $null) { Remove-PSSession -Session $script:session }
             if ($script:sessions -ne $null) { Remove-PSSession -Session $script:sessions }
             Write-Verbose -Verbose "AfterEach complete"
         }
+        #>
 
         It "Verifies new connection with implicit current User" {
             Write-Verbose -Verbose "It Starting: Verifies new connection with implicit current User"
@@ -301,9 +303,13 @@ Describe "SSHRemoting Basic Tests" -tags CI {
 
     Context "SSH Remoting API Tests" {
 
+        <#
         AfterEach {
+            Write-Verbose -Verbose "Starting Runspace close AfterEach"
             if ($script:rs -ne $null) { $script:rs.Dispose() }
+            Write-Verbose -Verbose "AfterEach complete"
         }
+        #>
 
         $testCases = @(
             @{

From 3332b2ff9671ac64db2ccff406af7f8e209a307c Mon Sep 17 00:00:00 2001
From: Paul Higinbotham <paulhi@microsoft.com>
Date: Mon, 12 Apr 2021 10:40:21 -0700
Subject: [PATCH 11/22] [Feature]


From 3d82ad64d216970105615f287ded8f195254d381 Mon Sep 17 00:00:00 2001
From: Paul Higinbotham <paulhi@microsoft.com>
Date: Mon, 12 Apr 2021 10:47:32 -0700
Subject: [PATCH 12/22] [Feature]


From 0079c52c2530459281c736dc3d6a942bdce26bbf Mon Sep 17 00:00:00 2001
From: Paul Higinbotham <paulhi@microsoft.com>
Date: Mon, 12 Apr 2021 11:05:15 -0700
Subject: [PATCH 13/22] Debug1

---
 test/SSHRemoting/SSHRemoting.Basic.Tests.ps1 | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1 b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
index 19c290d52ac..5d4bfd3c094 100644
--- a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
+++ b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
@@ -37,6 +37,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
         )
 
         Write-Verbose -Verbose "Starting TryNewPSSession ..."
+        return $null
 
         # Try creating a new SSH connection
         $timeout = $script:TestConnectingTimeout
@@ -76,6 +77,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
         )
 
         Write-Verbose -Verbose "Starting TryNewPSSessionHash ..."
+        return $null
 
         foreach ($connect in $SSHConnection)
         {
@@ -116,6 +118,11 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             [System.Management.Automation.Runspaces.PSSession] $session
         )
 
+        if ($null -eq $session)
+        {
+            return
+        }
+
         Write-Verbose -Verbose "VerifySession called for session: $($session.Id)"
 
         $session.State | Should -BeExactly 'Opened'
@@ -234,6 +241,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
         )
 
         Write-Verbose -Verbose "Starting TryCreateRunspace ..."
+        return $null
 
         $timeout = $script:TestConnectingTimeout
         $connectionError = $null
@@ -276,6 +284,11 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             [runspace] $rs
         )
 
+        if ($null -eq $rs)
+        {
+            return
+        }
+
         Write-Verbose -Verbose "VerifyRunspace called for runspace: $($rs.Id)"
 
         $rs.RunspaceStateInfo.State | Should -BeExactly 'Opened'

From a770916f3fa474a95b93c9efe056dfe058434277 Mon Sep 17 00:00:00 2001
From: Paul Higinbotham <paulhi@microsoft.com>
Date: Mon, 12 Apr 2021 11:38:36 -0700
Subject: [PATCH 14/22] Debug2

---
 test/SSHRemoting/SSHRemoting.Basic.Tests.ps1 | 25 +++++++-------------
 1 file changed, 9 insertions(+), 16 deletions(-)

diff --git a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1 b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
index 5d4bfd3c094..3a629398de0 100644
--- a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
+++ b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
@@ -37,7 +37,6 @@ Describe "SSHRemoting Basic Tests" -tags CI {
         )
 
         Write-Verbose -Verbose "Starting TryNewPSSession ..."
-        return $null
 
         # Try creating a new SSH connection
         $timeout = $script:TestConnectingTimeout
@@ -77,7 +76,6 @@ Describe "SSHRemoting Basic Tests" -tags CI {
         )
 
         Write-Verbose -Verbose "Starting TryNewPSSessionHash ..."
-        return $null
 
         foreach ($connect in $SSHConnection)
         {
@@ -139,20 +137,18 @@ Describe "SSHRemoting Basic Tests" -tags CI {
 
     Context "New-PSSession Tests" {
 
-        <#
         AfterEach {
             Write-Verbose -Verbose "Starting New-PSSession AfterEach"
             if ($script:session -ne $null) { Remove-PSSession -Session $script:session }
             if ($script:sessions -ne $null) { Remove-PSSession -Session $script:sessions }
             Write-Verbose -Verbose "AfterEach complete"
         }
-        #>
 
         It "Verifies new connection with implicit current User" {
             Write-Verbose -Verbose "It Starting: Verifies new connection with implicit current User"
             $script:session = TryNewPSSession -HostName localhost
             $script:session | Should -Not -BeNullOrEmpty
-            VerifySession $script:session
+            #VerifySession $script:session
             Write-Verbose -Verbose "It Complete"
         }
 
@@ -160,7 +156,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             Write-Verbose -Verbose "It Starting: Verifies new connection with explicit User parameter"
             $script:session = TryNewPSSession -HostName localhost -UserName (whoami)
             $script:session | Should -Not -BeNullOrEmpty
-            VerifySession $script:session
+            #VerifySession $script:session
             Write-Verbose -Verbose "It Complete"
         }
 
@@ -169,7 +165,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             $sessionName = 'TestSessionNameA'
             $script:session = TryNewPSSession -HostName localhost -Name $sessionName
             $script:session | Should -Not -BeNullOrEmpty
-            VerifySession $script:session
+            #VerifySession $script:session
             $script:session.Name | Should -BeExactly $sessionName
             Write-Verbose -Verbose "It Complete"
         }
@@ -179,7 +175,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             $portNum = 22
             $script:session = TryNewPSSession -HostName localhost -Port $portNum
             $script:session | Should -Not -BeNullOrEmpty
-            VerifySession $script:session
+            #VerifySession $script:session
             Write-Verbose -Verbose "It Complete"
         }
 
@@ -189,7 +185,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             $subSystem = 'powershell'
             $script:session = TryNewPSSession -HostName localhost -Port $portNum -SubSystem $subSystem
             $script:session | Should -Not -BeNullOrEmpty
-            VerifySession $script:session
+            #VerifySession $script:session
             Write-Verbose -Verbose "It Complete"
         }
 
@@ -200,7 +196,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             $subSystem = 'powershell'
             $script:session = TryNewPSSession -HostName localhost -Port $portNum -SubSystem $subSystem -KeyFilePath $keyFilePath
             $script:session | Should -Not -BeNullOrEmpty
-            VerifySession $script:session
+            #VerifySession $script:session
             Write-Verbose -Verbose "It Complete"
         }
 
@@ -224,8 +220,8 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             $script:sessions | Should -HaveCount 2
             $script:sessions[0].Name | Should -BeLike 'Connection*'
             $script:sessions[1].Name | Should -BeLike 'Connection*'
-            VerifySession $script:sessions[0]
-            VerifySession $script:sessions[1]
+            #VerifySession $script:sessions[0]
+            #VerifySession $script:sessions[1]
             Write-Verbose -Verbose "It Complete"
         }
     }
@@ -241,7 +237,6 @@ Describe "SSHRemoting Basic Tests" -tags CI {
         )
 
         Write-Verbose -Verbose "Starting TryCreateRunspace ..."
-        return $null
 
         $timeout = $script:TestConnectingTimeout
         $connectionError = $null
@@ -316,13 +311,11 @@ Describe "SSHRemoting Basic Tests" -tags CI {
 
     Context "SSH Remoting API Tests" {
 
-        <#
         AfterEach {
             Write-Verbose -Verbose "Starting Runspace close AfterEach"
             if ($script:rs -ne $null) { $script:rs.Dispose() }
             Write-Verbose -Verbose "AfterEach complete"
         }
-        #>
 
         $testCases = @(
             @{
@@ -380,7 +373,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             Write-Verbose -Verbose "It Starting: $TestName"
             $script:rs = TryCreateRunspace -UserName $UserName -ComputerName $ComputerName -KeyFilePath $KeyFilePath -Port $Port -Subsystem $Subsystem
             $script:rs | Should -Not -BeNullOrEmpty
-            VerifyRunspace $script:rs
+            #VerifyRunspace $script:rs
             Write-Verbose -Verbose "It Complete"
         }
     }

From 9b51d70fbf20ba239481e2d3a9fe0beebe07a37e Mon Sep 17 00:00:00 2001
From: Paul Higinbotham <paulhi@microsoft.com>
Date: Mon, 12 Apr 2021 13:15:35 -0700
Subject: [PATCH 15/22] Debug3

---
 test/SSHRemoting/SSHRemoting.Basic.Tests.ps1 | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1 b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
index 3a629398de0..b3c7535d717 100644
--- a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
+++ b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
@@ -148,7 +148,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             Write-Verbose -Verbose "It Starting: Verifies new connection with implicit current User"
             $script:session = TryNewPSSession -HostName localhost
             $script:session | Should -Not -BeNullOrEmpty
-            #VerifySession $script:session
+            VerifySession $script:session
             Write-Verbose -Verbose "It Complete"
         }
 
@@ -156,7 +156,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             Write-Verbose -Verbose "It Starting: Verifies new connection with explicit User parameter"
             $script:session = TryNewPSSession -HostName localhost -UserName (whoami)
             $script:session | Should -Not -BeNullOrEmpty
-            #VerifySession $script:session
+            VerifySession $script:session
             Write-Verbose -Verbose "It Complete"
         }
 
@@ -165,7 +165,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             $sessionName = 'TestSessionNameA'
             $script:session = TryNewPSSession -HostName localhost -Name $sessionName
             $script:session | Should -Not -BeNullOrEmpty
-            #VerifySession $script:session
+            VerifySession $script:session
             $script:session.Name | Should -BeExactly $sessionName
             Write-Verbose -Verbose "It Complete"
         }
@@ -175,7 +175,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             $portNum = 22
             $script:session = TryNewPSSession -HostName localhost -Port $portNum
             $script:session | Should -Not -BeNullOrEmpty
-            #VerifySession $script:session
+            VerifySession $script:session
             Write-Verbose -Verbose "It Complete"
         }
 
@@ -185,7 +185,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             $subSystem = 'powershell'
             $script:session = TryNewPSSession -HostName localhost -Port $portNum -SubSystem $subSystem
             $script:session | Should -Not -BeNullOrEmpty
-            #VerifySession $script:session
+            VerifySession $script:session
             Write-Verbose -Verbose "It Complete"
         }
 
@@ -196,7 +196,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             $subSystem = 'powershell'
             $script:session = TryNewPSSession -HostName localhost -Port $portNum -SubSystem $subSystem -KeyFilePath $keyFilePath
             $script:session | Should -Not -BeNullOrEmpty
-            #VerifySession $script:session
+            VerifySession $script:session
             Write-Verbose -Verbose "It Complete"
         }
 
@@ -220,8 +220,8 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             $script:sessions | Should -HaveCount 2
             $script:sessions[0].Name | Should -BeLike 'Connection*'
             $script:sessions[1].Name | Should -BeLike 'Connection*'
-            #VerifySession $script:sessions[0]
-            #VerifySession $script:sessions[1]
+            VerifySession $script:sessions[0]
+            VerifySession $script:sessions[1]
             Write-Verbose -Verbose "It Complete"
         }
     }

From 3a47c803b1041ac33cde77a93e2bcff9ca041acd Mon Sep 17 00:00:00 2001
From: Paul Higinbotham <paulhi@microsoft.com>
Date: Mon, 12 Apr 2021 13:34:12 -0700
Subject: [PATCH 16/22] Debug4

---
 .../engine/remoting/fanin/OutOfProcTransportManager.cs    | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs b/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
index 5b7f3b31c0b..61d87f76618 100644
--- a/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
+++ b/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
@@ -585,13 +585,13 @@ internal override void CloseAsync()
 
             try
             {
-                // send Close signal to the server and let it die gracefully.
-                stdInWriter.WriteLine(OutOfProcessUtils.CreateClosePacket(Guid.Empty));
-
                 // start the timer..so client can fail deterministically
                 _closeTimeOutTimer.Change(60 * 1000, Timeout.Infinite);
+
+                // send Close signal to the server and let it die gracefully.
+                stdInWriter.WriteLine(OutOfProcessUtils.CreateClosePacket(Guid.Empty));
             }
-            catch (IOException)
+            catch
             {
                 // Cannot communicate with server.  Allow client to complete close operation.
                 shouldRaiseCloseCompleted = true;

From 70dfcd4e3476f6098a0df8e1d890d4b006727956 Mon Sep 17 00:00:00 2001
From: Paul Higinbotham <paulhi@microsoft.com>
Date: Mon, 12 Apr 2021 14:05:07 -0700
Subject: [PATCH 17/22] Debug5

---
 .../engine/remoting/fanin/OutOfProcTransportManager.cs      | 6 +++---
 test/SSHRemoting/SSHRemoting.Basic.Tests.ps1                | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs b/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
index 61d87f76618..7fe2aba3b8d 100644
--- a/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
+++ b/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
@@ -585,11 +585,11 @@ internal override void CloseAsync()
 
             try
             {
-                // start the timer..so client can fail deterministically
-                _closeTimeOutTimer.Change(60 * 1000, Timeout.Infinite);
-
                 // send Close signal to the server and let it die gracefully.
                 stdInWriter.WriteLine(OutOfProcessUtils.CreateClosePacket(Guid.Empty));
+
+                // start the timer..so client can fail deterministically
+                _closeTimeOutTimer.Change(60 * 1000, Timeout.Infinite);
             }
             catch
             {
diff --git a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1 b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
index b3c7535d717..71407d4e297 100644
--- a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
+++ b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
@@ -373,7 +373,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             Write-Verbose -Verbose "It Starting: $TestName"
             $script:rs = TryCreateRunspace -UserName $UserName -ComputerName $ComputerName -KeyFilePath $KeyFilePath -Port $Port -Subsystem $Subsystem
             $script:rs | Should -Not -BeNullOrEmpty
-            #VerifyRunspace $script:rs
+            VerifyRunspace $script:rs
             Write-Verbose -Verbose "It Complete"
         }
     }

From 0dfde2b8e062ed800a9fd34a40315bbfeb72fc54 Mon Sep 17 00:00:00 2001
From: Paul Higinbotham <paulhi@microsoft.com>
Date: Mon, 12 Apr 2021 14:48:52 -0700
Subject: [PATCH 18/22] Final change

---
 test/SSHRemoting/SSHRemoting.Basic.Tests.ps1 | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1 b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
index 71407d4e297..e5c7ac3d743 100644
--- a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
+++ b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
@@ -8,7 +8,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
 
     $script:TestConnectingTimeout = 5000    # Milliseconds
 
-    function CheckSSHDService
+    function RestartSSHDService
     {
         if ($IsWindows)
         {
@@ -48,12 +48,12 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             $session = New-PSSession @PSBoundParameters -ConnectingTimeout $timeout -ErrorVariable connectionError -ErrorAction SilentlyContinue
             if ($null -eq $session)
             {
-                Write-Verbose -Verbose "SSH New-PSSession remoting connect failed after $($timeout/1000) second wait."
+                Write-Verbose -Verbose "SSH New-PSSession remoting connect failed."
 
                 if ($count -eq 1)
                 {
                     # Try restarting sshd service
-                    CheckSSHDService
+                    RestartSSHDService
                 }
             }
         }
@@ -91,12 +91,12 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             $session = New-PSSession @PSBoundParameters -ErrorVariable connectionError -ErrorAction SilentlyContinue
             if ($null -eq $session)
             {
-                Write-Verbose -Verbose "SSH New-PSSession remoting connect failed after $($timeout/1000) second wait."
+                Write-Verbose -Verbose "SSH New-PSSession remoting connect failed."
 
                 if ($count -eq 1)
                 {
                     # Try restarting sshd service
-                    CheckSSHDService
+                    RestartSSHDService
                 }
             }
         }
@@ -216,7 +216,6 @@ Describe "SSHRemoting Basic Tests" -tags CI {
                 Subsystem = 'powershell'
             })
             $script:sessions = TryNewPSSessionHash -SSHConnection $sshConnection -Name 'Connection1','Connection2'
-            $script:session | Should -Not -BeNullOrEmpty
             $script:sessions | Should -HaveCount 2
             $script:sessions[0].Name | Should -BeLike 'Connection*'
             $script:sessions[1].Name | Should -BeLike 'Connection*'
@@ -254,19 +253,19 @@ Describe "SSHRemoting Basic Tests" -tags CI {
             {
                 $connectionError = $_
                 $rs = $null
-                Write-Verbose -Verbose "SSH Runspace Open remoting connect failed after $($timeout/1000) second wait."
+                Write-Verbose -Verbose "SSH Runspace Open remoting connect failed."
 
                 if ($count -eq 1)
                 {
                     # Try restarting sshd service
-                    CheckSSHDService
+                    RestartSSHDService
                 }
             }
         }
 
         if ($null -eq $rs)
         {
-            $message = "Runspace open unable to connect to SSH remoting endpoint after three attempts. Error: $($connectionError.Message)"
+            $message = "Runspace open unable to connect to SSH remoting endpoint after two attempts. Error: $($connectionError.Message)"
             throw [System.Management.Automation.PSInvalidOperationException]::new($message)
         }
 

From 430b3a29bf623a525230ca2d3504538059b4441c Mon Sep 17 00:00:00 2001
From: Paul Higinbotham <paulhi@microsoft.com>
Date: Mon, 12 Apr 2021 16:17:24 -0700
Subject: [PATCH 19/22] Modify close logic to catch specific exceptions

---
 .../engine/remoting/fanin/OutOfProcTransportManager.cs         | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs b/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
index 7fe2aba3b8d..a5478bfd3b5 100644
--- a/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
+++ b/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
@@ -591,8 +591,9 @@ internal override void CloseAsync()
                 // start the timer..so client can fail deterministically
                 _closeTimeOutTimer.Change(60 * 1000, Timeout.Infinite);
             }
-            catch
+            catch (Exception ex) when (ex is IOException || ex is ObjectDisposedException)
             {
+
                 // Cannot communicate with server.  Allow client to complete close operation.
                 shouldRaiseCloseCompleted = true;
             }

From 922962d2fdeeb6e01a0b6ad4f56dad3eb8873e8f Mon Sep 17 00:00:00 2001
From: Paul Higinbotham <paulhi@microsoft.com>
Date: Tue, 13 Apr 2021 09:19:43 -0700
Subject: [PATCH 20/22] Implement review comments

---
 .../engine/remoting/commands/PSRemotingCmdlet.cs          | 7 ++++---
 .../engine/remoting/common/RunspaceConnectionInfo.cs      | 8 ++++++--
 .../engine/remoting/fanin/OutOfProcTransportManager.cs    | 3 +--
 .../resources/RemotingErrorIdStrings.resx                 | 3 ++-
 4 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/src/System.Management.Automation/engine/remoting/commands/PSRemotingCmdlet.cs b/src/System.Management.Automation/engine/remoting/commands/PSRemotingCmdlet.cs
index 840b6c301d7..62bc698bda6 100644
--- a/src/System.Management.Automation/engine/remoting/commands/PSRemotingCmdlet.cs
+++ b/src/System.Management.Automation/engine/remoting/commands/PSRemotingCmdlet.cs
@@ -771,9 +771,10 @@ public virtual string KeyFilePath
 
         /// <summary>
         /// Gets or sets a value in milliseconds that limits the time allowed for an SSH connection to be established.
+        /// Default timeout value is infinite.
         /// </summary>
         [Parameter(ParameterSetName = PSRemotingBaseCmdlet.SSHHostParameterSet)]
-        public virtual int ConnectingTimeout { get; set; } = -1;    // No timeout by default
+        public virtual int ConnectingTimeout { get; set; } = -1;
 
         /// <summary>
         /// This parameter specifies that SSH is used to establish the remote
@@ -910,7 +911,7 @@ protected void ParseSshHostName(string hostname, out string host, out string use
         /// <returns>Array of SSHConnection objects.</returns>
         internal SSHConnection[] ParseSSHConnectionHashTable()
         {
-            var connections = new List<SSHConnection>();
+            List<SSHConnection> connections = new();
             foreach (var item in this.SSHConnection)
             {
                 if (item.ContainsKey(ComputerNameParameter) && item.ContainsKey(HostNameAlias))
@@ -923,7 +924,7 @@ internal SSHConnection[] ParseSSHConnectionHashTable()
                     throw new PSArgumentException(RemotingErrorIdStrings.SSHConnectionDuplicateKeyPath);
                 }
 
-                var connectionInfo = new SSHConnection();
+                SSHConnection connectionInfo = new();
                 foreach (var key in item.Keys)
                 {
                     string paramName = key as string;
diff --git a/src/System.Management.Automation/engine/remoting/common/RunspaceConnectionInfo.cs b/src/System.Management.Automation/engine/remoting/common/RunspaceConnectionInfo.cs
index 77c4592dba7..dba6a557e6f 100644
--- a/src/System.Management.Automation/engine/remoting/common/RunspaceConnectionInfo.cs
+++ b/src/System.Management.Automation/engine/remoting/common/RunspaceConnectionInfo.cs
@@ -1913,7 +1913,11 @@ public sealed class SSHConnectionInfo : RunspaceConnectionInfo
         /// Default value for subsystem.
         /// </summary>
         private const string DefaultSubsystem = "powershell";
-        private const int DefaultConnectingTimeoutTime = -1;    // Never time out
+        
+        /// <summary>
+        /// Default value is infinite timeout.
+        /// </summary>
+        private const int DefaultConnectingTimeoutTime = -1;
 
         #endregion
 
@@ -2028,7 +2032,7 @@ public SSHConnectionInfo(
             int port,
             string subsystem) : this(userName, computerName, keyFilePath, port)
         {
-            Subsystem = (string.IsNullOrEmpty(subsystem)) ? DefaultSubsystem : subsystem;
+            Subsystem = string.IsNullOrEmpty(subsystem) ? DefaultSubsystem : subsystem;
         }
 
         /// <summary>
diff --git a/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs b/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
index a5478bfd3b5..3272a6363b1 100644
--- a/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
+++ b/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
@@ -593,7 +593,6 @@ internal override void CloseAsync()
             }
             catch (Exception ex) when (ex is IOException || ex is ObjectDisposedException)
             {
-
                 // Cannot communicate with server.  Allow client to complete close operation.
                 shouldRaiseCloseCompleted = true;
             }
@@ -1683,7 +1682,7 @@ internal override void CreateAsync()
                     var errorMessage = StringUtil.Format(RemotingErrorIdStrings.SSHClientConnectTimeout, _connectionInfo.ConnectingTimeout / 1000);
                     if (sshTerminated)
                     {
-                        errorMessage += "\n" + RemotingErrorIdStrings.SSHClientConnectProcessTerminated;
+                        errorMessage += RemotingErrorIdStrings.SSHClientConnectProcessTerminated;
                     }
 
                     HandleSSHError(
diff --git a/src/System.Management.Automation/resources/RemotingErrorIdStrings.resx b/src/System.Management.Automation/resources/RemotingErrorIdStrings.resx
index 664033e20bd..441228c9c44 100644
--- a/src/System.Management.Automation/resources/RemotingErrorIdStrings.resx
+++ b/src/System.Management.Automation/resources/RemotingErrorIdStrings.resx
@@ -1629,7 +1629,8 @@ All WinRM sessions connected to PowerShell session configurations, such as Micro
     <value>SSH connection attempt failed after time out: {0} seconds.</value>
   </data>
   <data name="SSHClientConnectProcessTerminated" xml:space="preserve">
-    <value>SSH client process terminated before connection could be established.</value>
+    <value>
+SSH client process terminated before connection could be established.</value>
   </data>
   <data name="MissingRequiredSSHParameter" xml:space="preserve">
     <value>The provided SSHConnection hashtable is missing the required ComputerName or HostName parameter.</value>

From bd137f207737220b29d43412b2bdfa1a4589ce6e Mon Sep 17 00:00:00 2001
From: Paul Higinbotham <paulhi@microsoft.com>
Date: Tue, 13 Apr 2021 10:11:29 -0700
Subject: [PATCH 21/22] Resolve more comment change requests

---
 .../engine/remoting/commands/PSRemotingCmdlet.cs               | 3 ++-
 .../engine/remoting/common/RunspaceConnectionInfo.cs           | 2 +-
 .../engine/remoting/fanin/OutOfProcTransportManager.cs         | 2 ++
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/System.Management.Automation/engine/remoting/commands/PSRemotingCmdlet.cs b/src/System.Management.Automation/engine/remoting/commands/PSRemotingCmdlet.cs
index 62bc698bda6..40be7ec2503 100644
--- a/src/System.Management.Automation/engine/remoting/commands/PSRemotingCmdlet.cs
+++ b/src/System.Management.Automation/engine/remoting/commands/PSRemotingCmdlet.cs
@@ -15,6 +15,7 @@
 using System.Management.Automation.Remoting;
 using System.Management.Automation.Remoting.Client;
 using System.Management.Automation.Runspaces;
+using System.Threading;
 
 using Dbg = System.Management.Automation.Diagnostics;
 
@@ -774,7 +775,7 @@ public virtual string KeyFilePath
         /// Default timeout value is infinite.
         /// </summary>
         [Parameter(ParameterSetName = PSRemotingBaseCmdlet.SSHHostParameterSet)]
-        public virtual int ConnectingTimeout { get; set; } = -1;
+        public virtual int ConnectingTimeout { get; set; } = Timeout.Infinite;
 
         /// <summary>
         /// This parameter specifies that SSH is used to establish the remote
diff --git a/src/System.Management.Automation/engine/remoting/common/RunspaceConnectionInfo.cs b/src/System.Management.Automation/engine/remoting/common/RunspaceConnectionInfo.cs
index dba6a557e6f..a16e7820bd1 100644
--- a/src/System.Management.Automation/engine/remoting/common/RunspaceConnectionInfo.cs
+++ b/src/System.Management.Automation/engine/remoting/common/RunspaceConnectionInfo.cs
@@ -1917,7 +1917,7 @@ public sealed class SSHConnectionInfo : RunspaceConnectionInfo
         /// <summary>
         /// Default value is infinite timeout.
         /// </summary>
-        private const int DefaultConnectingTimeoutTime = -1;
+        private const int DefaultConnectingTimeoutTime = Timeout.Infinite;
 
         #endregion
 
diff --git a/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs b/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
index 3272a6363b1..ff206938879 100644
--- a/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
+++ b/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
@@ -1657,6 +1657,7 @@ internal override void CreateAsync()
             }
 
             // Start connection timeout timer if requested.
+            // Timer callback occurs only once after timeout time.
             _connectionTimer = new Timer(
                 callback: (_) => 
                 {
@@ -1685,6 +1686,7 @@ internal override void CreateAsync()
                         errorMessage += RemotingErrorIdStrings.SSHClientConnectProcessTerminated;
                     }
 
+                    // Report error and terminate connection attempt.
                     HandleSSHError(
                         new PSRemotingTransportException(errorMessage));
                 },

From 082b50a3c0bc2ac3cff04c54a1ecbcbedd46e567 Mon Sep 17 00:00:00 2001
From: Paul Higinbotham <paulhi@microsoft.com>
Date: Tue, 13 Apr 2021 10:21:15 -0700
Subject: [PATCH 22/22] Previously neglected to commit test change

---
 test/SSHRemoting/SSHRemoting.Basic.Tests.ps1 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1 b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
index e5c7ac3d743..7383cc2b8a1 100644
--- a/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
+++ b/test/SSHRemoting/SSHRemoting.Basic.Tests.ps1
@@ -18,7 +18,7 @@ Describe "SSHRemoting Basic Tests" -tags CI {
         }
         else
         {
-            Write-Verbose -Verbose "Restarting Linux SSHD service..."
+            Write-Verbose -Verbose "Restarting Unix SSHD service..."
             sudo service ssh restart
             $status = sudo service ssh status
             Write-Verbose -Verbose "SSHD service status: $status"