SSH Error: Invalid packet size. The packet is too large.

Problem loggin into an ssh server.

Trying to log in from the same PC to the same host, Flash fails but FileZilla works. the version of flash is , would you be able to assist?


Flash version
4,3,1 (build 1951)


[R] Connecting to MFT-a -> IP=142.225.180.64 PORT=22
[R] Connected to MFT-a
[R] Host key algorithm ssh-RSA, size 1024 bits.
[R] Fingerprint (MD5): 81:c6:54:a8:d1:c7:ca:60:00:4c:20:b8:06:3e:0d:c0
[R] Key exchange: diffie-hellman-group1-sha1. Session encryption: aes256-cbc, MAC: hmac-sha1, compression: none.
[R] Auth Type: Password
[R] Authentication succeeded
[R] SSH Connection open
[R] SSH Error: Invalid packet size. The packet is too large.
[R] SSH Connection closed (User Disconnected)
[R] Connection failed (Unable to access SFTP sub-system, operation failed.)


FileZilla Debug

10:56:15 Status: Connecting to 142.225.180.64...
10:56:15 Trace: Going to execute "C:\Program Files\FileZilla FTP Client\fzsftp.exe"
10:56:15 Response: fzSftp started
10:56:15 Trace: CSftpControlSocket::ConnectParseResponse(fzSftp started)
10:56:15 Trace: CSftpControlSocket::SendNextCommand()
10:56:15 Trace: CSftpControlSocket::ConnectSend()
10:56:15 Command: open "MFTERPMPAD@142.225.180.64" 22
10:56:15 Trace: Looking up host "142.225.180.64"
10:56:15 Trace: Connecting to 142.225.180.64 port 22
10:56:15 Trace: Server version: SSH-2.0-Maverick_SSHD
10:56:15 Trace: Using SSH protocol version 2
10:56:15 Trace: We claim version: SSH-2.0-PuTTY_Local:_Nov_10_2012_20:56:41
10:56:15 Trace: Doing Diffie-Hellman group exchange
10:56:15 Trace: Doing Diffie-Hellman key exchange with hash SHA-1
10:56:16 Trace: Host key fingerprint is:
10:56:16 Trace: ssh-rsa 1024 81:c6:54:a8:d1:c7:ca:60:00:4c:20:b8:06:3e:0d:c0
10:56:16 Trace: Initialised AES-256 CBC client->server encryption
10:56:16 Trace: Initialised HMAC-SHA1 client->server MAC algorithm
10:56:16 Trace: Initialised AES-256 CBC server->client encryption
10:56:16 Trace: Initialised HMAC-SHA1 server->client MAC algorithm
10:56:16 Command: Pass: ******
10:56:16 Trace: Sent password
10:56:18 Trace: Access granted
10:56:18 Trace: Opened channel for session
10:56:20 Trace: Started a shell/command
10:56:20 Status: Connected to 142.225.180.64
10:56:20 Trace: CSftpControlSocket::ConnectParseResponse()
10:56:20 Trace: CSftpControlSocket::ResetOperation(0)
10:56:20 Trace: CControlSocket::ResetOperation(0)
10:56:20 Trace: CFileZillaEnginePrivate::ResetOperation(0)
10:56:20 Status: Retrieving directory listing...
10:56:20 Trace: CSftpControlSocket::SendNextCommand()
10:56:20 Trace: CSftpControlSocket::ChangeDirSend()
10:56:20 Command: pwd
10:56:20 Response: Current directory is: "/"
10:56:20 Trace: CSftpControlSocket::ResetOperation(0)
10:56:20 Trace: CControlSocket::ResetOperation(0)
10:56:20 Trace: CSftpControlSocket::ParseSubcommandResult(0)
10:56:20 Trace: CSftpControlSocket::ListSubcommandResult()
10:56:20 Trace: state = 1
10:56:20 Trace: CSftpControlSocket::SendNextCommand()
10:56:20 Trace: CSftpControlSocket::ListSend()
10:56:20 Trace: state = 2
10:56:20 Command: ls
10:56:20 Status: Listing directory /
10:56:20 Trace: CSftpControlSocket::ListParseResponse()
10:56:20 Trace: CSftpControlSocket::SendNextCommand()
10:56:20 Trace: CSftpControlSocket::ListSend()

10:56:20 Trace: state = 3

10:56:20 Status: Calculating timezone offset of server...

10:56:20 Command: mtime "Inbox"

10:56:20 Response: 1366124180

10:56:20 Trace: CSftpControlSocket::ListParseResponse(1366124180)

10:56:20 Status: Timezone offsets: Server: -14400 seconds. Local: -14400 seconds. Difference: 0 seconds.

10:56:20 Trace: CSftpControlSocket::ResetOperation(0)

10:56:20 Trace: CControlSocket::ResetOperation(0)

10:56:20 Status: Directory listing successful

10:56:20 Trace: CFileZillaEnginePrivate::ResetOperation(0)

Would it be possible to create a test account for me on this server? If so please send me the information via a private message and I will look into it.

Unfortunaly the server is secure and only accessible through a private line. What I do know is the IP Flash is conencting to is a NATed ip. I can ofcourse help if you semd me instructions hopefully that helps.

I'm afraid this is a difficult situation to diagnose by any other means, I will try to see if I can get a copy of Maverick SSHD running on a machine for testing and go from there.

great, let me know , we are planning to put this into production but if it can't be fixed will have to find another way.

tminchev@rpmtec.com

I haven't had any luck trying to get this SSH server up and running.

Do you have access to the server side logs for the SSH/SFTP server? Perhaps there is something in the logs that can help us better understand the problem.

I have been trying to figure out a way to add debugging to help assist in troubleshooting this problem but due to the nature of this issue I am not 100% sure what would help.

If the packet size is in fact invalid then perhaps the packet sent to FlashFXP is unexpected or invalid, but I am thinking perhaps maybe that is not the case. While doing some tests with against another SFTP server I noticed that if the connection is prematurely or unexpectedly closed by the server it can result in this error as well.

I am using FlashFXP 4.4.4 (2043). A customer has same issue also against a Maverick based SFTP server. I don't have access myself (IPSec/firewalled), but from their end it works in WinSCP and PSFTP, but fails in FlashFXP, Putty and Putty based libraries. FlashFXP fails with packet length error above and Putty library sshlib!_allmul seems to loop during dir listing.

I want to debug more, but hard without repro SFTP server. Do you have this Maverick SFTP installation trial or access to a server which I can get a test account on? PM please if you have.

Originally Posted by raven

I am using FlashFXP 4.4.4 (2043). A customer has same issue also against a Maverick based SFTP server. I don't have access myself (IPSec/firewalled), but from their end it works in WinSCP and PSFTP, but fails in FlashFXP, Putty and Putty based libraries. FlashFXP fails with packet length error above and Putty library sshlib!_allmul seems to loop during dir listing.

I want to debug more, but hard without repro SFTP server. Do you have this Maverick SFTP installation trial or access to a server which I can get a test account on? PM please if you have.

Maverick SSHD is a java api framework for creating customized SFTP server.

You can't simply download and configure it.

http://www.sshtools.com/products/maverick-sshd

It turns out this SFTP server is IBM Sterling File Gateway / Secure Proxy, which is based on Maverick APIs it seems. IBM Sterling support has this old article about the issue.
http://www-01.ibm.com/support/docvie...id=swg21560137

Is there something that can be fixed in FlashFXP to be able to Connect to it. In WinSCP changing from SFTP version 5 to either 4 or 3 works. I don't see any options for this in FlashFXP.