Rebex SFTP: Error while sending packet data.

Question

From time to time we receive such errors

#1 Error occurred. UserName: null IpAddress: "*.*.*.*(hidden manually)" ExceptionType: "rgxfn.tdxux" Message: "Error while sending packet data." StackTrace: "   at rgxfn.uvvsl.mjcqq(zjspz p0, Action p1)
   at rgxfn.uvvsl.izpqt()
   at rgxfn.uvvsl.lcmin()
   at rgxfn.uvvsl.ilmbf()
   at rgxfn.uvvsl.damjc(Int32 p0, Int32 p1, Int32 p2, Int32 p3, SocketException p4)"

#2 Error occurred. UserName: null IpAddress: "*.*.*.*(hidden manually)" ExceptionType: "rgxfn.tdxux" Message: "Unsupported protocol version." StackTrace: "   at rgxfn.uvvsl.lcmin()
   at rgxfn.uvvsl.ilmbf()
   at rgxfn.uvvsl.damjc(Int32 p0, Int32 p1, Int32 p2, Int32 p3, SocketException p4)"

Such errors appear quite often. Stacktrace looks like this:

// Error 1
void Server.eqmfj(ServerSession p0, Type p1, Exception p2)
void sjukm.cieeb(object p0, ihfky p1)
void uvvsl.ahhhj(Exception p0)
void uvvsl.damjc(int p0, int p1, int p2, int p3, SocketException p4)

// Error 2
void Server.eqmfj(ServerSession p0, Type p1, Exception p2)
void sjukm.cieeb(object p0, ihfky p1)
void uvvsl.ahhhj(Exception p0)
void uvvsl.damjc(int p0, int p1, int p2, int p3, SocketException p4)

We assume that it is a bad client that is connecting to sftp server, but maybe it is a wrong assumption. Can you please clarify what is happening?

Comments

Could you please let us know which version of Rebex File Server you use?

---

Version is - 5.0.7731

Answer 1

Error 1: The "Error while sending packet data" error indicates a failure at TCP socket level. In .NET terms, it means that SocketException occurred during Socket.Send call when attempting to send SSH packet data. The original SocketException should have been logged into a log at LogLevel.Error level, so you can find it there.

Error 2: This occurs when the client attempting to connect advertises itself as an SSH version other than 2.0 (or 1.99, which is also interpreted as 2.0). This could easily be simulated by connecting using telnet and typing "SSH-1.0-Test" followed by Enter.

Apparently, the exception type obfuscation (and lack of inner exception in the first case) makes these hard to decipher. We'll address that in one of the next releases. Thanks for bringing it to our attention!