OpenWrt/LEDE: dropbear & MIPS & gcc 7.1.0

[Syrone Wong]

Hi,

I think it's a bug in libtommath. Compiling both 2017.75 and 2017.75
with updated libtom*, the latter one works while the original one
doesn't. And for other parts, such as kernel, busybox, userspace
programs, etc. , all of them are working perfectly. That's the reason
why I think it isn't a compiler bug.

Sorry, since I cannot access the router, which means I cannot execute
any commands, it's not trivial to get the backtrace.

Based on Kevin's report,

> ssh -vvv' shows things hanging during the initial ECDH key exchange

it might be something wrong with key verification, I'm not sure about
it, totally wildly guess.

You may want to contact Kevin off-list to know how he finds the issue
resides in libtommath, I just follow his guess and replace libtom* to
verify his idea.

Kevin Darbyshire-Bryant <kevin at darbyshire-bryant.me.uk>


Best Regards,
Syrone Wong