Error, SFTP: Unknown recipient channel: 0

Questions dealing with specific FTP clients and Cerberus FTP Server.
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Error, SFTP: Unknown recipient channel: 0

Post by vendorIT » Tue Oct 04, 2011 11:42 pm

Hey there. Am trying to get BizTalk running the /n software SFTP adapter to connect to Cerberus running SFTP, but am getting an 'Unknown recipient channel: 0' error when BizTalk trys to connect to the server. Below are the logs from Cerberus.

Can someone please confirm if this is a problem with the SFTP server or client? Any help would be much appreciated.

2011/10/05 16:23:58 [22] Incoming connection request on SSH interface 2 at 10.x.x.x
2011/10/05 16:23:58 [22] SSH FTP connection request accepted from 10.x.x.x
2011/10/05 16:23:58 [22] Algorithm negotiation complete: Proceeding with key exchange
2011/10/05 16:23:58 [22] Kex: 'diffie-hellman-group1-sha1' Host Key: 'ssh-rsa' C2S : '3des-cbc, hmac-sha1, none' S2C : '3des-cbc, hmac-sha1, none'
2011/10/05 16:23:59 [22] DH Key sizes: Server Public '1023', Private '1023', Client Public '1017'
2011/10/05 16:24:01 [22] Authenticating password for user 'test'
2011/10/05 16:24:01 [22] Native user 'test' authenticated
2011/10/05 16:24:01 [22] Channel Open: 'session', Sender Channel: 0, Init Window Size: 1048576, Max Packet Size: 524288
2011/10/05 16:24:01 [22] Creating local channel: 336
2011/10/05 16:24:01 [22] Channel Request: 'subsystem', Recipient Channel: 0, Subsystem Name: 'sftp', Reply: true
2011/10/05 16:24:01 [22] Unknown recipient channel: 0
2011/10/05 16:24:58 [22] The client closed the connection
2011/10/05 16:24:58 [22] Connection terminated

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Re: Error, SFTP: Unknown recipient channel: 0

Post by Serin » Thu Oct 06, 2011 3:03 am


I already answered this via email but I thought I would post the result to the forum also:

It looks like a bug in the BizTalk SFTP adapter. The SFTP client is requesting to open an SFTP channel but is requesting it on the wrong recipient channel. It looks like the client has the sender and recipient channel reversed. We've tested with dozens of other clients that do this correctly so it definitely appears to be a client bug. We always validate request parameters so the server is properly rejecting the request.

Is there a newer version of the adapter you can use? Perhaps they've fixed this problem in a newer version.

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