Default root password in imagebuilder

For Developers
1

I'm following this page https://openwrt.org/docs/guide-user/additional-software/imagebuilder, since I'm trying to set a default password during building. I have tryed to put command strings into a custom files. But the router boots an empty password.

cat <<EOF > ~/Documents/openwrt/openwrt-imagebuilder-24.10.0-rc4-ramips-mt7621.Linux-x86_64/files/etc/uci-defaults/99_default-password
# echo 'Updating root password'
NEWPASSWD=123456
passwd <<EOP
echo "\${NEWPASSWD}"
sleep1
echo "\${NEWPASSWD}"
exit 0 # IMPORTANT, if we no put this, will executed endlessly
EOP
EOF

Any help is appreciated

2

Create password hash and replace root_password_hash value

mkpasswd -m sha-256

99_default-password file contents

root_password_hash='$5$PPtQyQFcE8glNo0h$UlGDOa2h4hSEsrrz4PtzisgSXZMccF5eM1VuPg.Fji6'
grep -q "$root_password_hash" /etc/shadow||sed -i "s|^root::|root:$root_password_hash:|" /etc/shadow
exit 0
3

do I need to create this value with a host computer (I am on archlinux: mkpasswd -m sha-256 - bash: mkpasswd: command not found) or on openwrt router?

4

Ok, just checking!
Do you have a working serial connection on this device before proceeding?
And what is your plan B?

5

I actually have a openwrt image booted, up and running, before I flash the new image with the default password. thanks!
And yes, I can have a serial connection throught router's jtags, and in case something goes wrong I have factory image and use the reset button.

1 Like
6

Yes or you can use openssl in openwrt
openssl passwd -5

7

it worked like a charm. here is the strings to set the default password during building:

cat <<EOF > ~/Documents/openwrt/openwrt-imagebuilder-24.10.0-rc4-ramips-mt7621.Linux-x86_64/files/etc/uci-defaults/99_default-password
# echo 'Setting default root password: xxxxxxx  ->'xxxxxxxxxxxxxxxxxxxxxxxxxxxxx'
root_password_hash='xxxxxxxxxxxxxxxxxxxxxxxxxxxxx'
grep -q "\$root_password_hash" /etc/shadow||sed -i "s|^root::|root:\$root_password_hash:|" /etc/shadow
exit 0
EOF
3 Likes
8

Two things:

  1. Don't post your root password online
  2. Use ssh key if you want to connect via ssh

For LuCi access it doesn't really matter if your password is empty or admin. Equally easy to access.

9

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