RISC OS cryptography software


SSH (Secure Shell) software

Please note that newer versions of psftp, pscp and plink may now be found in the Unix Porting Project (archive 'putty' in directory 'terminal'). These left here are merely for historical interest

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Current versions are:

puttytools, SSHProxy and pscp are clients for the SSH protocol, which allows secure connections between computers over networks that may be eavesdropped by others or subject to security attacks by third parties. puttytools support the SSH protocol version 2, whilst SSHProxy and historical pscp only support version 1. They are based on the Windows SSH client PuTTY. To run they need CryptRandom (see below) to be installed.

SSHProxy provides SSH terminal sessions, whilst psftp and pscp perform file transfer. plink does X11 and port forwarding, and allows the running of programs on the remote computer (similar to rsh).

Why might you want to use SSH instead of telnet, FTP, rlogin or rcp? There are plenty of guides on the web - one example is from Berkeley

I have also compiled a 32 bit compatible version of NettleSSH, by Justin Fletcher and the Nettle developers, which is an SSH v1 client integrated into the Nettle terminal emulator/telnet client, with rlogin and rexec support added too. This is an unofficial release, and since I haven't made any changes to the code it retains the same version number of 0.2023 but with “32-bit” appended. Any bugs in this version are probably mine, so please don't ask Justin to support it. Source is included.

CryptRandom

Current version is 0.12 (download binaries, sources). This is RISC OS 5 compatible. Version history. CVSWeb.


Security advisory for CryptRandom versions 0.05 to 0.08 inclusive (dated 3 November 2002).

CryptRandom is a module for generating cryptographically useful random bytes under RISC OS.

Why?

Computers are, by their nature, deterministic - so applying the same sequence of inputs to any program is likely to produce the same result. This is a bad thing when it comes to cryptography, as if you use a known sequence to encrypt a data stream, next time you turn on your machine you'll use the same known sequence, making the code possible to break. Thus we need a random sequence so that no pattern can be spotted in it. Basic provides a pseudo-random sequence, but this is the same every time the machine is turned on, so is not very good. It is also just a sequence, which will eventually repeat. True randomness is only possible on a computer by attaching it to other devices such as a radioactive source - not very practical. CryptRandom applies another method, which will produce different values showing to no known pattern, which are different each time you switch the machine on. This is much less secure than using a true random source, but better than using a predictable random number generator like that Basic uses. See the readme file for more details on how it works.

SHA1 module

Current version is 0.03 (download binaries, sources - same source archive as CryptRandom above). This is RISC OS 5 compatible. Version history. CVSWeb.

SHA1 is a module for generating a SHA-1 message digest under RISC OS.

Other SSH software

For completeness, links are included here to SSH software produced by other developers. You might find some of this software better than

Page by Theo Markettos (email at theo@markettos.org.uk), autogenerated 22 June 2005

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