[paramiko] HPN-SSH

[Robey Pointer]

On 13 Feb 2008, at 6:48, James Bardin wrote:

> The following looks pretty interesting:
>
> http://www.psc.edu/networking/projects/hpn-ssh/
>
> I wonder if any of these patches could apply to paramiko (not directly
> of course)?  I don't know if we could multithread using pycrypto, but
> the more important improvement would be dynamic windows and possibly  
> the
> None cipher.

Adding a None cipher to paramiko would be easy, but of dubious  
usefulness.

Multithreading AES-CTR is pretty clever. If pycrypto supported CTR,  
paramiko could do the same trick as the HPN patches, because they're  
taking advantage of a feature of the CTR block chaining method: CTR  
chains just encipher a stream of incrementing numbers, and XOR the  
result against the actual data. They're just offloading the AES  
encryption to a worker thread, then XORing that stream against the  
data stream in the main thread (XOR is very fast). Very nice.

Dynamic windows should be equally possible (and hopefully easier in  
python than in C). The tricky part there would be checking the OS's  
TCP buffer size, etc.

robey