IT08800: (SFTP) SSH CLIENT USING SFTP PROTOCOL VERSION4 FAILS

3.4.2.0-SterlingSecureProxy-AIX-if0002
3.4.2.0-SterlingSecureProxy-HP-IA-if0002
3.4.2.0-SterlingSecureProxy-Linux-if0002
3.4.2.0-SterlingSecureProxy-SolarisSPARC-if0002
3.4.2.0-SterlingSecureProxy-Windows-if0002
3.4.2.0-SterlingSecureProxy-Linux_s390-if0002
3.4.2.0-SterlingSecureProxy-AIX-if0004
3.4.2.0-SterlingSecureProxy-HP-IA-if0004
3.4.2.0-SterlingSecureProxy-Linux_s390-if0004
3.4.2.0-SterlingSecureProxy-Linux-if0004
3.4.2.0-SterlingSecureProxy-SolarisSPARC-if0004
3.4.2.0-SterlingSecureProxy-Windows-if0004
3.4.2.0-SterlingSecureProxy-AIX-if0005
3.4.2.0-SterlingSecureProxy-HP-IA-if0005
3.4.2.0-SterlingSecureProxy-Linux_s390-if0005
3.4.2.0-SterlingSecureProxy-Linux-if0005
3.4.2.0-SterlingSecureProxy-SolarisSPARC-if0005
3.4.2.0-SterlingSecureProxy-Windows-if0005

APAR status

• Closed as program error.

Error description

• SFTP Protocol version 4 and higher not working
  
  We have a partner who is not able to upload/download files via
  SFTP using WS_FTP.  I've been able to replicate the issue with
  WS_FTP and WinSCP.   It appears to be an issue when SFTP
  protocol version 4 or higher is used.  I don't get an error
  when using version 3.  I have attached logs to show when
  version 3 is used and then version 4.  This was using WinSCP
  and I have attached the WinSCP client log, SSP adapter and
  netmap logs as well as the backend SI server adapter log.  We
  are on Version 3.4.2.0, Fix 1, Build 157 on Linux.
  
  We also have Version 3.4.1.8, Fix 4, Build 86 on Linux
  installed in another environment and we are not seeing the same
  issues with it.
  
  (Note: Informed the user that we only work with version 3 & 4)
  
  Inhouse Test:
  Linux
  SSP Version: 3.4.2.0, Fix 1, Build 157
  WINSCP Client: Change SFTP Protocol = 4
  Backend Server: SI SFTP Adapter
  

Local fix

•  STRRTC - 463822
  RJ/RJ
  Circumvention:
  Update to latest SSP Build
  

Problem summary

• Description of issue:  A customer will notice that it cannot use
   sftp clients that are asking for any sftp version above version
   3. This has manifested as an inability to read the home
  directory in many of the clients that we have tested.
  

Problem conclusion

• Description of fix: We added code to make sure that an sftp
  handshake negotiates to version 3, which allows for ssp to
  correctly negotiate the sftp version between the client and
  backend server
  

Temporary fix

• Description of issue:  A customer will notice that it cannot use
   sftp clients that are asking for any sftp version above version
   3. This has manifested as an inability to read the home
  directory in many of the clients that we have tested.
  
  Description of fix: We added code to make sure that an sftp
  handshake negotiates to version 3, which allows for ssp to
  correctly negotiate the sftp version between the client and
  backend server
  

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  STR SECURE PROX

• Fixed component ID

  5725D0300

Applicable component levels

• R342 PSY

     UP