From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Korsgaard Date: Thu, 12 Mar 2015 16:25:30 +0100 Subject: [Buildroot] [PATCH] system: add option for standalone telnetd on target In-Reply-To: <1426147462.2639.11.camel@synopsys.com> (Alexey Brodkin's message of "Thu, 12 Mar 2015 08:04:33 +0000") References: <1426066527-23021-1-git-send-email-abrodkin@synopsys.com> <877funmrkw.fsf@dell.be.48ers.dk> <1426092262.2375.11.camel@synopsys.com> <87pp8flblh.fsf@dell.be.48ers.dk> <1426147462.2639.11.camel@synopsys.com> Message-ID: <87wq2mi6fp.fsf@dell.be.48ers.dk> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net >>>>> "Alexey" == Alexey Brodkin writes: Hi, > 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 feel lucky". >> 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: > [1] Enabled "dropbear": BR2_PACKAGE_DROPBEAR=y > [2] 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: ---> 8--- > $ 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 ---> 8--- 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