I have 1 Armbian installed in the SBC.

 

I want to login but I don't have any idea what is the root password.

 

I saw there are few methods of breaking it and can bypass / reset password.

 

I noticed that this method is 1 of the easiest way, but it doesn't work.

 

By editing  /etc/shadow,

root:$6$6fRIGsIb$dt.U84pEFgqpCSmlU9Nn2SLxBK8mYxxZMethrY35kqPg09aS/8e5xQ08excoGzdta6E5XmF2iFQC5J4EJVuM31:17401:0:99999:7:::
daemon:*:17326:0:99999:7:::
bin:*:17326:0:99999:7:::
sys:*:17326:0:99999:7:::
sync:*:17326:0:99999:7:::
games:*:17326:0:99999:7:::
man:*:17326:0:99999:7:::
lp:*:17326:0:99999:7:::
mail:*:17326:0:99999:7:::
news:*:17326:0:99999:7:::
uucp:*:17326:0:99999:7:::
proxy:*:17326:0:99999:7:::
www-data:*:17326:0:99999:7:::
backup:*:17326:0:99999:7:::
list:*:17326:0:99999:7:::
irc:*:17326:0:99999:7:::
gnats:*:17326:0:99999:7:::
nobody:*:17326:0:99999:7:::
systemd-timesync:*:17326:0:99999:7:::
systemd-network:*:17326:0:99999:7:::
systemd-resolve:*:17326:0:99999:7:::
systemd-bus-proxy:*:17326:0:99999:7:::
messagebus:*:17326:0:99999:7:::
ntp:*:17326:0:99999:7:::
avahi-autoipd:*:17326:0:99999:7:::
sshd:*:17326:0:99999:7:::
rbcs:$6$SMHou.Qx$ZFNh7PSANkFtf7LtUnkBlMZNzoPw5Yj8VHhvpwcpbyvTI4AqIN.NEpWL2uSDI1dVuJLZrh2WS05yyPhHalwRI/:17401:0:99999:7:::
gpsd:*:17401:0:99999:7:::

Which segment to be removed?
root:$6$6fRIGsIb$dt.U84pEFgqpCSmlU9Nn2SLxBK8mYxxZMethrY35kqPg09aS/8e5xQ08excoGzdta6E5XmF2iFQC5J4EJVuM31:17401:0:99999:7:::

I tried many times by removing "$6$6fRIGsIb$dt.U84pEFgqpCSmlU9Nn2SLxBK8mYxxZMethrY35kqPg09aS/8e5xQ08excoGzdta6E5XmF2iFQC5J4EJVuM31" and with left with the new line of:-

root::17401:0:99999:7::: <---- Is this correct or I am done something very wrong. 

 

Please advise and thank you in advance.

 

Regards.

You've done it right, but passwd can NOT be left empty as describe in "man shadow" :

Quote

This field may be empty, in which case no passwords are required to authenticate as the specified login name. However, some applications which read the /etc/shadow file may decide
           not to permit any access at all if the password field is empty.

 

So, if you have another board with a known working password, copy the encrypted passwd from one board to the other, it should work.

1 hour ago, martinayotte said:

You've done it right, but passwd can NOT be left empty as describe in "man shadow" :

 

So, if you have another board with a known working password, copy the encrypted passwd from one board to the other, it should work.

Hi martinayotte,

 

Thanks for the reply.

 

Great info.

 

Best regards.

On 8/28/2018 at 12:46 AM, martinayotte said:

You've done it right, but passwd can NOT be left empty as describe in "man shadow" :

Will removing the password hash result in it being replaced with the hash of the default password?

 

funny story, i created two files in /etc/sudoers.d and mistakenly left the alias the same. now I can't sudo anything to fix it!!