Various small fixes

Author: papafe

src/MongoDB.Driver/Core/Configuration/ConnectionString.cs

@@ -1071,7 +1071,7 @@ private void ParseOption(string name, string value)
                     var proxyPortValue = ParseInt32(name, value);
                     if (proxyPortValue is < 1 or > 65535)
                     {
-                        throw new MongoConfigurationException("proxyPort must be between 0 and 65535.");
+                        throw new MongoConfigurationException($"Invalid proxy port: {proxyPortValue}: must be between 1 and 65535, inclusive.");
                     }
                     _proxyPort = proxyPortValue;
                     break;

src/MongoDB.Driver/Core/Connections/Socks5Helper.cs

@@ -106,10 +106,10 @@ public static void PerformSocks5Handshake(Stream stream, EndPoint endPoint, Sock
             stream.Write(buffer, 0, greetingRequestLength);
 
             stream.ReadBytes(buffer, 0, 2, cancellationToken);
-            var acceptsUsernamePasswordAuth = ProcessGreetingResponse(buffer, useAuth);
+            var requiresAuthenticationStep = ProcessGreetingResponse(buffer, useAuth);
 
-            // If we have username and password, but the proxy doesn't need them, we skip.
-            if (useAuth && acceptsUsernamePasswordAuth)
+            // If we have username and password, but the proxy doesn't need them, we skip the authentication step.
+            if (requiresAuthenticationStep)
             {
                 var authenticationRequestLength = CreateAuthenticationRequest(buffer, authenticationSettings);
                 stream.Write(buffer, 0, authenticationRequestLength);
@@ -143,10 +143,10 @@ public static async Task PerformSocks5HandshakeAsync(Stream stream, EndPoint end
             await stream.WriteAsync(buffer, 0, greetingRequestLength, cancellationToken).ConfigureAwait(false);
 
             await stream.ReadBytesAsync(buffer, 0, 2, cancellationToken).ConfigureAwait(false);
-            var acceptsUsernamePasswordAuth = ProcessGreetingResponse(buffer, useAuth);
+            var requiresAuthenticationStep = ProcessGreetingResponse(buffer, useAuth);
 
             // If we have username and password, but the proxy doesn't need them, we skip.
-            if (useAuth && acceptsUsernamePasswordAuth)
+            if (requiresAuthenticationStep)
             {
                 var authenticationRequestLength = CreateAuthenticationRequest(buffer, authenticationSettings);
                 await stream.WriteAsync(buffer, 0, authenticationRequestLength, cancellationToken).ConfigureAwait(false);
@@ -202,7 +202,7 @@ private static bool ProcessGreetingResponse(byte[] buffer, bool useAuth)
 
         if (acceptedMethod != MethodNoAuth)
         {
-            throw new IOException("SOCKS5 proxy requires unsupported authentication method.");
+            throw new IOException($"SOCKS5 proxy requires unsupported authentication method. Unsupported method: {acceptedMethod}");
         }
 
         return false;
@@ -228,7 +228,7 @@ private static void ProcessAuthenticationResponse(byte[] buffer)
     {
         if (buffer[0] != SubnegotiationVersion || buffer[1] != Socks5Success)
         {
-            throw new IOException("SOCKS5 authentication failed.");
+            throw new IOException($"SOCKS5 authentication failed. Version: {buffer[0]}, Status: {buffer[1]}.");
         }
     }
 
@@ -277,7 +277,7 @@ private static int ProcessConnectResponse(byte[] buffer)
 
         if (buffer[1] != Socks5Success)
         {
-            throw new IOException($"SOCKS5 connect failed");
+            throw new IOException($"SOCKS5 connect failed. Error code: {buffer[1]}");
         }
 
         // We skip the last bytes of the response as we do not need them.
@@ -297,7 +297,7 @@ private static void VerifyProtocolVersion(byte version)
     {
         if (version != ProtocolVersion5)
         {
-            throw new IOException("Invalid SOCKS version in response.");
+            throw new IOException($"Invalid SOCKS version in response. Expected version {ProtocolVersion5}, but received {version}.");
         }
     }
 

src/MongoDB.Driver/Core/Connections/Socks5ProxySettings.cs

@@ -135,8 +135,8 @@ public override string ToString()
 
         sb.Append(Authentication switch
         {
-            Socks5AuthenticationSettings.UsernamePasswordAuthenticationSettings up =>
-                $"UsernamePassword (Username: {up.Username}, Password: {up.Password})",
+            Socks5AuthenticationSettings.UsernamePasswordAuthenticationSettings =>
+                "UsernamePassword",
             _ => "None"
         });
 

src/MongoDB.Driver/MongoUrlBuilder.cs

@@ -468,11 +468,7 @@ public int? ProxyPort
             get => _proxyPort;
             set
             {
-                if (value is null)
-                {
-                    throw new ArgumentNullException(nameof(ProxyPort));
-                }
-                _proxyPort = Ensure.IsBetween(value.Value, 1, 65535, nameof(ProxyPort));
+                _proxyPort = Ensure.IsNullOrBetween(value, 1, 65535, nameof(ProxyPort));
             }
         }