Software Requirements

In order to use all of the features of WebSubmit, certain supporting software must be installed.  Depending on the situation on your chosen WebSubmit server, some of the software you need may already be installed.

A Note on Server and Target Platforms (Operating Systems)
At present, WebSubmit is requires a UNIX system for its server and assumes UNIX target systems.  The dependencies on UNIX are mostly incidental and minor, and arise from applying WebSubmit to an application domain (high performance batch computing) that is strongly UNIX  associated.  Neither the technology nor the implementation tools are UNIX-restricted.  One minor exception is that Expect is not yet available for Windows NT.  Thus some other support for binary file transfer would be required, e.g., ftp.  Another exception of sorts is that Secure Shell (SSH) for Windows is a commercial product.  We use SSH to communicate between the WebSubmit server and the target systems.

A Note on Client Platforms (Operating Systems/Browsers)
Client systems may be UNIX or Windows.  However, we have only tested the software with the Netscape browsers (level 4 or higher).  In addition, at the moment we are using components of Netscape's LiveConnect software in our target-side file browser.   Compatibility with a wider range of browsers is one of our goals for the next release.

Tcl/Tk
All of the WebSubmit libaries and modules are written in Tcl (the Tool Command Language); the WebSubmit Configuration Manager is the onl;y component of the package written in Tcl/Tk.  Tcl code is interpreted (not compiled), and hence a Tcl interpreter imust be running on the WebSubmit server.  The code is compatible with Tcl interpreters at version 8.0 or higher.  We are using verison 8.0.  Tcl/Tk is freeware and is available from the Scriptics web site:http://www.scriptics.com/software/8.0.html.  Your system may have a suitable version of Tcl/Tk installed already.

Expect (Tcl Extenmsion)
Expect is a Tcl extension written by Don Libes at NIST.  It is required to enable binary file transfers in the file transfer modules.  Expect-5.28 is included with the distribution in the extensions/expect-5.28 directory of the distribution and can be compiled using the Makefile.  Expect may already be installed on your system.

CGI Library (Tcl Extension)
CGI scripts in WebSubmit are written with the aid of Don Libes' excellent cgi.tcl library.   Version of this software (0.7.5) is included with the WebSubmit distribution in the extensions/cgi.tcl directory.  This is the most recent release that WebSubmit has been tested with and past experience suggests that cgi.tcl updates can be incompatible with previous versions.

Tcl-Bin (Tcl Extension)
TclBin is an extension to Tcl that supports binary data objects and structures.  This code is required for authentication.  It has been included in the WebSubmit distribution in extensions/tclbin-1.2.

Web Server(s)
WebSubmit obvious requires a Web server and the security framework in WebSubmit relies largely on (a) properly configured Web server(s).   This server must meet several requirements in order for the authentication techniques used in WebSubmit to be functional.  An insecure (HTTP) server is used to allow unregistered users to gain access to a restricted subset of the system, and also to register.  A secure (HTTPS) server is required for the primary WebSubmit applications.  The requirements for the HTTPS server are as follows:

  1. The server must possess the ability to perform transactions using the Secure Sockets Layer (SSL) protocol and to authenticate clients using this protocol
  2. The server must be able to place a base-64 encoded version of the certificate into the CGI environment.
These requirements are not unduely stringent.  The original WebSubmit software was developed using a Netscape Enterprise Server (v3.0).  This server provides a simple directive to place the certificate into the CGI environment and is capable of using SSL.  Apache-SSL is another server capable of performing the desired tasks for WebSubmit (see http://www.apache-ssl.org).  More details on the authentication framework and Web servers can be found in the section on Authentication.

Secure Shell (SSH) and Secure Copy (SCP)
Remote command execution in WebSubmit is accomplished using the Secure Shell (SSH) and Secure Copy (SCP) protocols.  It is necessary to use these protocols to avoid potential security breaches due to IP or DNS spoofing.  SSH and SCP should be installed on the server and all target systems;  these pieces of software are available at http://www.cs.hut.fi/ssh/.  It is recommended that sites install SSH v1.2.26 or greater for interoperability with the emerging SSH v2.x standard.  Regretably, at the moment we do not support SSH2.  Which means you'll have to use an older version of SSH if your system has SSH2 installed.  SSH2 compatibility is pending in the next release.