SSH for small uPs

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Does anyone know of SSH for small uPs, 8-bit Atmel AVR preferred.
If not possible for 8-bit, what is the smallest embedded uP it is possible for?
Is there any SSH Freeware, preferably OS independent?

Thanks - Ken

Re: SSH for small uPs
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The private key encryption could take minutes on an AVR. Try something
with more power and a hardware multiplier, like the larger MSP430's.

Re: SSH for small uPs
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Client or server?  I don't know of any cross platform servers (they tend to
be mixed up with things like terminals and processes on the host machine)
but there are some cross platform ish clients - for example PuTTY (Free): /

Whilst the front end is tied to Windows, the backend is fairly easy to
extract and use separately.  

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8 bit would be pushing it.  A statistic I heard is that a 386 could do
5Mbits/sec blowfish at full tilt under Linux - but key exchange is probably
going to be the slow bit (my Linux 386 OpenSSH server took a minute or two,
literally, to do a login - though it had 4MB of RAM so had to swap a fair
bit).  My feeling for this (based on a bit of experience and a lot of
guessing) is that a 68K or 386 class CPU would be a reasonable minimum.  I'd
say you need C as a basic minimum unless you feel like handcrafting this in
assembler (it's about the same complexity as writing a TCP/IP stack except
there aren't as many shortcuts).


Theo Markettos       
Liphook, Hampshire, UK
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Re: SSH for small uPs (Ken) wrote in message
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You should look at 16 bits integer DSPs for the public key
cryptography computations. The general purpose processor that will do
your protocol does not have the right instruction set ("hardware
multiplier" is a small portion of the solution) for decent speed for
key setup.

- Thierry Moreau

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