[Buildroot] [PATCH] system: add option for standalone telnetd on target
peter at korsgaard.com
Thu Mar 12 15:25:30 UTC 2015
>>>>> "Alexey" == Alexey Brodkin <Alexey.Brodkin at synopsys.com> writes:
> Well probably it was in days of WinXP when Telnet was pre-installed.
> Still as you may see from the article - there's a way to install
> "native" Telnet client from Windows update/software sources.
Yes, but it doesn't seem significantly easier than google + pytty + "I
>> Don't they ask the same about the serial login password?
> That's exactly the point for serial port as well as for Telnet we may
> not use password for root - which is a default case in Buildroot.
With ssh you could use a ssh key instead.
>> > Indeed your proposal may work if my motivation is not convincing enough.
>> I can still be convinced, but my initial thought is that it isn't
>> really a common enough use case / we should promote ssh instead.
> I tried your proposal with Dropbear but frankly with not much luck.
> What I did:
>  Enabled "dropbear": BR2_PACKAGE_DROPBEAR=y
>  Set root password: BR2_TARGET_GENERIC_ROOT_PASSWD="xxx"
> What's nice Dropbear auto-starts on boot. But...
> Now on attempt to ssh to the target I see:
> $ ssh root at 192.168.218.2
> root at 192.168.218.2's password:
> PTY allocation request failed on channel 0
> shell request failed on channel 0
Odd, I'm using it every day. Anything of interest in syslog? Perhaps you
are missing a kernel config. Do you have CONFIG_UNIX98_PTYS=y?
> Another inconvenience I discovered with SSH - every time I boot my
> target it gets new fingerprint and then on attempt to ssh to the target
> I see:
Yeah, that's part of the extra security of ssh. Either drop the cached
key or add pregenerated keys in your rootfs.
> I may assume this is because I have filesystem built-in kernel (vmlinux)
> so between boots filesystem doesn't preserve any information - but in
> case of simulators we usually don't have any other options.
You could always add a static set of keys in your rootfs overlay. Not
really ideal from a security POV, but still better than telnet.
Bye, Peter Korsgaard
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