Trying to repro Rekeying issue #1764

test/Renci.SshNet.IntegrationTests/Dockerfile

@@ -18,6 +18,7 @@ RUN apk update && apk upgrade --no-cache && \
     # Set the default RSA key
     echo 'HostKey /etc/ssh/ssh_host_rsa_key' >> /etc/ssh/sshd_config && \
     echo 'TrustedUserCAKeys /etc/ssh/user-ca.pub' >> /etc/ssh/sshd_config && \
+    echo 'RekeyLimit 1M 0' >> /etc/ssh/sshd_config && \
     chmod 646 /etc/ssh/sshd_config && \
     # install and configure sudo
     apk add --no-cache sudo && \

test/Renci.SshNet.IntegrationTests/OldIntegrationTests/SftpClientTest.Upload.cs

@@ -482,5 +482,25 @@ public async Task Test_Sftp_UploadFileAsync_UploadProgress()
                 Assert.IsTrue(callbackCalled);
             }
         }
+
+#if NET
+        [TestMethod]
+        public async Task Test_SftpUpload_WithLowRekeyLimit()
+        {
+            using (var sftp = new SftpClient(SshServerHostName, SshServerPort, User.UserName, User.Password))
+            {
+                await sftp.ConnectAsync(CancellationToken.None);
+
+                await Parallel.ForEachAsync(Enumerable.Range(0, 10), async (i, ct) =>
+                {
+                    var filename = Path.GetTempFileName();
+                    int testFileSizeMB = 100;
+                    CreateTestFile(filename, testFileSizeMB);
+                    using var fileStream = File.OpenRead(filename);
+                    await sftp.UploadFileAsync(fileStream, "test" + i, ct);
+                });
+            }
+        }
+#endif
     }
 }

test/Renci.SshNet.TestTools.OpenSSH/SshdConfig.cs

@@ -426,6 +426,7 @@ private static void ProcessGlobalOption(SshdConfig sshdConfig, string line)
                 case "PasswordAuthentication":
                 case "GatewayPorts":
                 case "Include":
+                case "RekeyLimit":
                     break;
                 default:
                     throw new NotSupportedException($"Global option '{name}' is not supported.");