#!/usr/bin/env python

# WARNING
# This script completely destroys your ~/.ssh/authorized_keys
# file every time it is run
# WARNING

import sys
import os
import os.path
import ruleset
import subprocess

if len(sys.argv) != 3:
    sys.stderr.write("refresh-auth: wrong number of arguments (%s)\n" % sys.argv)
    sys.exit(-1)

akeyfile = sys.argv[1]
wrappercommand = sys.argv[2]
prefix='no-pty,no-port-forwarding,no-X11-forwarding,no-agent-forwarding,command='

if os.path.exists(akeyfile):
    f = open(akeyfile)
    try:
        for l in f:
            if not l.startswith(prefix):
                raise Exception("Safety check failed, delete %s to continue" % akeyfile)
    finally:
        f.close()

akeys = open(akeyfile + "_new", "w")
for root, dirs, files in os.walk("keys"):
    for fn in files:
        ffn = os.path.join(root, fn)
        if not ruleset.goodpath(ffn):
            # ignore any path that contains dodgy characters
            continue
        keyname = ffn[5:]
        if keyname == "root":
            # No key can claim root privileges
            continue
        p = subprocess.Popen(("ssh-keygen", "-i", "-f", ffn), 
            stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        newkey = p.communicate()[0]
        if p.wait() == 0:
            klines = [l.strip() for l in newkey.split("\n")]
        else:
            # Conversion failed, read it directly.
            kf = open(ffn)
            try:
                klines = [l.strip() for l in kf]
            finally:
                kf.close()
        for l in klines:
            if len(l):
                akeys.write('%s"%s %s" %s\n' % (prefix, wrappercommand, keyname, l))

akeys.close()

os.rename(akeyfile + "_new", akeyfile)