#!/usr/bin/env python

import logging
import signal
import sys

log = logging.getLogger(__name__)

TIMEOUT = 5

try:
    import pam
except ImportError:
    log.debug("PAM auth helper: Could not import pam module")
    sys.exit(1)


def handle_timeout(signum, stack):
    raise OSError("Timed out reading input")


# set timeout so we don't block on reading stdin
signal.alarm(TIMEOUT)

pam_service = sys.stdin.readline().strip()
pam_username = sys.stdin.readline().strip()
pam_password = sys.stdin.readline().strip()

# cancel the alarm
signal.alarm(0)

p_auth = pam.pam()
authenticated = p_auth.authenticate(pam_username, pam_password, service=pam_service)
if authenticated:
    log.debug(f"PAM auth helper: authentication successful for {pam_username}")
    sys.stdout.write("True\n")
    sys.exit(0)
else:
    log.debug(f"PAM auth helper: authentication failed for {pam_username}")
    sys.stdout.write("False\n")
    sys.exit(1)