[Contents] [Index]

About This Document >>     Installing SSH Tectia Server for IBM z/OS >>     Getting Started with SSH Tectia Server for IBM z/OS >>     Configuring the Server >>     Authentication >>     File Transfer Using SFTP >>     Secure File Transfer Using Transparent FTP Security >>         Introduction to Transparent FTP Security         Configuring SOCKS Proxy >>         Creating the SSHSP User         Running SOCKS Proxy >>         Using Public-Key Authentication with the SOCKS Proxy >>         Configuring FTP >>         Examples of Transparent FTP Security>>     Tunneling >>     Troubleshooting SSH Tectia Server for IBM z/OS >>     Man Pages and Default Configuration Files >>     Log Messages >>

Introduction to Transparent FTP Security

Transparent FTP tunneling and FTP-SFTP conversion can be used to secure both interactive and unattended FTP sessions. They provide a quick and easy way to secure FTP file transfers without the need to change existing FTP jobs or scripts.

• Transparent FTP tunneling

  Transparent FTP tunneling is implemented using the SSH Tectia SOCKS Proxy component. SSH Tectia SOCKS Proxy acts as a SOCKS proxy for the FTP client application on the SSH Tectia Server for IBM z/OS host and captures FTP connections based on filter rules. The tunneling is transparent to the user and the FTP application. The only change needed in the FTP application is to change the SOCKS proxy setting to point to a localhost listener.

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  Figure : The architecture of transparent FTP tunneling

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  The SOCKS Proxy uses the hostname, username, and password information provided by the FTP client application to open an authenticated and encrypted tunnel to a Secure Shell server. Alternatively, public-key authentication can be used for opening the tunnel

  The Secure Shell server can also defined in the filter rules. In this case, the secure tunnel is terminated at the Secure Shell server and from there the FTP connection is forwarded to the FTP server unsecured.

• FTP-SFTP conversion

  FTP-SFTP conversion is implemented using the SSH Tectia SOCKS Proxy component. SSH Tectia SOCKS Proxy acts as a SOCKS proxy for the FTP client application on the SSH Tectia Server for IBM z/OS host and captures FTP connections based on filter rules. FTP connections are converted to SFTP, transparently to the user and the FTP application. The only change needed in the FTP application is to change the SOCKS proxy setting to point to a localhost listener.

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  Figure : The architecture of FTP-SFTP conversion

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  The SOCKS Proxy uses the hostname, username, and password information provided by the FTP client application to open an authenticated and encrypted SFTP connection to a Secure Shell SFTP server. Alternatively, public-key authentication can be used for opening the SFTP connection.

  The Secure Shell SFTP server can also defined in the filter rules. This way, the client's request for the FTP server destination can be overridden.

To enable transparent FTP tunneling and FTP-SFTP conversion, you need to complete the following tasks:

1. Configure the SSH Tectia SOCKS Proxy to listen on port 1080 on the client host and define the filter rules in the ssh-socks-proxy-config.xml configuration file. See Section Configuring SOCKS Proxy.
2. Create a user, for example SSHSP, for running the SOCKS Proxy. See Section Creating the SSHSP User.
3. Start the ssh-socks-proxy process. See Section Running SSH Tectia SOCKS Proxy.
4. (Optional) If you want to use public-key authentication with passphrase-protected keys, use the ssh-socks-proxy-ctl tool to give the passphrases to the keys and load the keys in the memory. See Section Using Public-Key Authentication with the SOCKS Proxy.
5. Configure the SOCKS settings for the FTP client. See Section Configuring FTP.

After these tasks are completed, the specified FTP connections will be automatically tunneled or converted to SFTP, transparently to the user.