Wireless-enabled devices, the latest electronic marvels, are steadily becoming integral part of enterprise infrastructure due the tremendous benefits and advantages they bring. Compact, with fast Internet connection they provide a vast range of services but unfortunately there is a cost – generally speaking, wireless-enabled devices are far less secure than their wired counterparts.
The goal of this article is to introduce to the reader the two currently available SSH clients, which were designed for improving security of remote access and data transfer via Pocket PC devices. Both of them are free and could be downloaded from a few sites on the Internet.
PocketPutty – PocketPC 2003 SSH Client
PocketPutty is the “mini” version of the original Putty SSH client for Microsoft Windows platform. As opposed to many other Pocket PC programs, PocketPutty does not require installation process of any kind and could be run as soon as it has been copied to your Pocket PC.
The user interface is quite simple and intuitive. PocketPutty allows the user to choose between two levels of protection – SSH1/SSH2 and Telnet. The former is more secure while the latter is faster. Both SSH1 and SSH2 are based on strong cryptographic algorithms and differ by their implementation. To improve the speed of data transfer, PocketPutty has an option to use SSH compression, which trades off additional CPU times of compression/decompression for generally much lower volumes of data.
After clicking the “OK” button and supplying the connection credentials on the console screen the user is authenticated and connected to the remote machine and may start running commands from the regular shell prompt.
Even though PocketPutty is only in pre-alpha development status and lacks many of the original SSH features, the ease of usage and the lack of bugs (HP iPAQ 4355) guarantee a secure framework for working remotely.
Currently PocketPutty is available for Pocket PC 2003 only and it lacks private key authentication, SSH port selection (it uses the default SSH port) and few other less important features.
OpenSSH CE – Windows CE SSH Client
This Pocket PC SSH client is a ported version of one of the wonderful UNIX program – BSD SSH Client. It also does not require installation but unlike with PocketPutty, the user must manually perform few configuration steps prior to running the program work correctly. These steps include registry modification, system variable configuration and special setup for the folder tree of the Pocket PC.
Upon finishing the configuration and running the program, the user is presented with an UNIX-like console screen and prompted to enter connection credentials – machine name, username and password. Once the authentication process has been completed the user can work securely on the remote machine.
In addition to providing a secure framework for working remotely, OpenSSH CE includes some of the original features of BSD SSH. This includes the SCP – Security Copy Program, and SFTP – Secure FTP. Both of those programs require an UNIX-like console screen to run.
Overall OpenSSH CE is very useful, stable and close to the original SSH client. It has three obvious advantages over the PocketPutty: It supports secure file transfer, it is platform independent and the program is distributed with its source code, which allows programmers to add/change features to make the program suite their needs. However, OpenSSH CE requires much more time and effort to configure it correctly and make it work on your Pocket PC.