SAMA5D27_SOM1_EK Buildroot: permit root login via ssh

This forum is for users of Microchip MPUs and who are interested in using Linux OS.

Moderator: nferre

rdgtk
Posts: 3
Joined: Thu May 09, 2019 8:51 am

SAMA5D27_SOM1_EK Buildroot: permit root login via ssh

Thu May 09, 2019 9:50 am

Hi,
I'm new to Linux. I'm using SAMA5D27 SOM1 EK, and followed the instructions from the Linux4SAM Buildroot page.
I configure and make the system, and I get an img file and burn an SD card with Etcher. Everything goes fine:
-After inserting the SD and power up, the blue LED starts blinking.
-I connect to the console from my Ubuntu host via minicom and the system executes commands.
-I set and start eth0. The board takes an IP address from DHCP server and I can get answers to ping.

Now:
ssh server is up an running and accepts connections, but I can't log in as root nor as any other user: "Permission denied, please try again"
I modified /etc/ssh/sshd_config to "PermitRootLogin yes", I tryed with and without password and no success.
I tryed other sshd_config options after some examples from the net and also from my own Ubuntu host.

I'm connecting to ssh from my Ubuntu host, and also from a Windows host using Teraterm. These clients can log in with no problems to other systems, including this same board with a demo image.

What am I missing? Thank you for any suggestion.
blue_z
Location: USA
Posts: 1978
Joined: Thu Apr 19, 2007 10:15 pm

Re: SAMA5D27_SOM1_EK Buildroot: permit root login via ssh

Fri May 10, 2019 1:26 am

A /etc/ssh/sshd_config with
"PermitRootLogin yes",
"PermitEmptyPasswords yes", and
"ChallengeResponseAuthentication no"
allows me to ssh in as user "root" with no password.

Regards
rdgtk
Posts: 3
Joined: Thu May 09, 2019 8:51 am

Re: SAMA5D27_SOM1_EK Buildroot: permit root login via ssh

Tue May 14, 2019 1:26 pm

Thank you blue_z.
No success. I'm searching other reasons. I think it has to do with the authorized_keys file.
If I succeed I'll come back with the solution, for I suppose that everybody using Buildroot and following the instructions at Linux4Sam Buildroot will find the same problem.
Of course in the meanwhile any suggestion is welcome.
rdgtk
Posts: 3
Joined: Thu May 09, 2019 8:51 am

Re: SAMA5D27_SOM1_EK Buildroot: permit root login via ssh

Wed May 15, 2019 10:51 am

Problem solved!
I followed a friend's suggestion:
-List files at /etc/init.d
-If you find both S50dropbear and S50sshd, delete S50dropbear

The point was that two ssh servers were up.

By the way: I tryed keeping S50dropbear and deleting S50sshd instead and could not log in. So the solution is:
Delete /etc/init.d/S50dropbear

To any interested user: remember that I got to this problem when configuring my system specifically with Buildroot.
If you are using something different may be everything is OK concerning ssh and remote log in.

Sometimes friends are better than Google :D
blue_z
Location: USA
Posts: 1978
Joined: Thu Apr 19, 2007 10:15 pm

Re: SAMA5D27_SOM1_EK Buildroot: permit root login via ssh

Thu May 16, 2019 12:50 am

rdgtk wrote: To any interested user: remember that I got to this problem when configuring my system specifically with Buildroot.
The problem is not with Buildroot itself, but rather with which defconfig file you start your build.
For most Atmel/Microchip boards you can choose to build either a minimal root filesystem by specifying the plain <board>_defconfig file, or build almost a desktop environment on a SBC using the <board>_dev_defconfig file.
Of course you can then use `make menuconfig` to modify the package selections.
For whatever reason the SAMA5D27_SOM1_EK does not have a minimalist _defconfig file but only a _dev_defconfig file (and also demo, headless and nodered defconfigs in buildroot-external-microchip).

In buildroot-at91 from the Linux4SAM github, the Atmel <board>_dev_defconfig files specify both the OpenSSH and Dropbear packages, which lead to the problem you had.

Note that you would not encounter this issue if you download a recent Buildroot from buildroot.org.
The mainline versions of Atmel <board>_dev_defconfig files, including atmel_sama5d27_som1_ek_mmc_dev_defconfig, build the OpenSSH package but not Dropbear.
Microchip should be aware of this change, but apparently has not (yet) applied this commit to the Linux4SAM git.

Regards

Return to “LINUX”

Who is online

Users browsing this forum: Google [Bot] and 3 guests