lrpb

Means "last resort primitive backdoor".

For when you can't log in via ssh but something's still alive...

Requirements

• bash 4+
• GNU tar
• curl or wget
• signify from openbsd
• rsync
• ssh

Installation

make install

Client side usage

First, create a pair of keys:

signify -G -p myname.pub -s myname.sec

Then write a script you want to be launched on remote side:

#!/bin/sh
touch ~/helloworld-it-works

Write lrpb client config to client.conf:

# ssh config
upload_host=mydomain.org
upload_port=22
upload_user=user
upload_path=/home/user/www/lrpb

name=myname

signify_path=/bin/signify
seckey_path=./myname.sec

Finally, sign and upload it to some remote server you control:

lrpb upload -c ./client.conf -f ./script.sh

On remote server, set up some http server (nginx, lighttpd, apache, whatever) that serves directory you upload to. The script will upload archive name myname.tar.gz and it must be accessible by http.

Server side usage

Copy public key to /etc/lrpb.pub on the server (or anywhere you want, just make sure to set correct path in the config).

Write lrpb server config and save it to /etc/lrpb.conf:

url=https://mydomain.org/lrpb/
pubkey_path=/etc/lrpb.pub
name=myname
signify_path=/usr/bin/signify-openbsd
cwd=/var/lrpbfsq
cache_file=/var/lrpbfs/cache

Optionally, make /var/lrpbfs a tmpfs mountpoint. Add to /etc/fstab:

tmpfs /var/lrpbfs tmpfs size=1M,mode=1755,uid=1000,gid=1000 0 0

Then mount it:

mount /var/lrpbfs

Test that it works:

lrpb exec

Add task to crontab:

TERM=xterm
PATH=<you should enter your $PATH here>

0,30 * * * * /usr/local/bin/lrpb exec >/dev/null

License

BSD-2c