Providing default root password /etc/shadow

For Developers
1

Hi,
I am new to lede and trying to use openwrt for a fun project. The target board is rpi-b+ and it works as expected. However, there is no default password on the openwrt and have to set it up after booting the device. I know lede has the /etc/passwd and /etc/shadow file in the base-files package.
It would be great if someone can suggest me the way to update these two file to provide a default root password built into the firmware.

Thanks in advance,
Naz.

2

First set the password is a live router, then copy /etc/passwd and /etc/shadow from the router to your build environment and include them in the firmware build as custom files.

https://lede-project.org/docs/guide-developer/use-buildsystem#custom_files

https://forum.openwrt.org/viewtopic.php?pid=339453#p339453

1 Like
3

Thank you for your reply,
But it is not working always. I flashed the binaries 4 times, non of them had the password I provided. Also the sha256 sum is different after running -
make packages/base-files/{clean,compile} V=99
The compared files are {lede-buildroot}/build_dir/linux-bcm**/base-files**/etc/{shadow, passwd} and {lede-buildroot}/files/etc{shadow,passwd}

Am I doing something wrong?
Thanks again.

4

"Custom files" from {lede-buildroot}/files are not part of base-files package, but they are just inserted into the rootfs file system after all packages, including base-files, have been installed during the final make step. You need to make the whole firmware image, not just base-files. And then look at the root file system, not the contents of base-files (which only contains the "normal" default files).

E.g. in my ipq806x R7800, the custom files are in
build_dir/target-arm_cortex-a15+neon-vfpv4_musl_eabi/root-ipq806x/etc/

So, your {lede-buildroot}/build_dir/target**/linux-bcm**/base-files**/etc/{shadow, passwd} looks wrong. The correct place would be something like {lede-buildroot}/build_dir/target**/root-bcm**/etc/{shadow, passwd}
(Note, I corrected your path above to include the missing target that you had skipped.)

For more detailed info, see include/rootfs.mk from line 58 onward:
https://git.lede-project.org/?p=source.git;a=blob;f=include/rootfs.mk;hb=HEAD#l58

5

Thank you. It worked after performing a full build.

The link was very useful.

Regards

6

Is it possible to put it under {openwrt-buildroot}/files/etc/passwd? Do the files need any special permissions?

7

Yes, that will work. root ownership is set by the build process, so do not chown on it. chmod to match whatever is default or your preference.

2 Likes
8

Thanks Jeff, got it working. Just for the record, the defaults are 600 for /etc/shadow and 664 for /etc/passwd

1 Like
9

As well as copying the image /etc/passwd and /etc/shadow into files/etc/
I added files/etc/login.defs with ENCRYPT_METHOD MD5
and I use the following script to create a passwd:

#!/bin/sh

if [ $# -ne 1 ]
then
  echo "Usage: $0 <password>"
  exit 1
fi
ps1="${1}"
passwd=$(openssl passwd -1 ${ps1})
awk 'BEGIN {FS=":"; OFS=":";}  {if ($0 ~ /^root/) {print $1,"'$passwd'",$3,$4,$5,$6,"::";} else {print $0;}}' < files/etc/shadow > myshadow
mv myshadow files/etc/shadow
10

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