# Copyright 2008-2009 LShift Ltd

# WARNING

# This hook completely destroys your ~/.ssh/authorized_keys

# file every time it is run

# WARNING

import sys

import os

import os.path

import pwd

import subprocess

from mercurialserver import ruleset, paths

def refreshAuth():

    pentry = pwd.getpwuid(os.geteuid())

    if pentry.pw_name != "hg":

        # FIXME: re-execute

        print >>sys.stderr, "Must be run as the 'hg' user"

    akeyfile = pentry.pw_dir + "/.ssh/authorized_keys"

    wrappercommand = paths.getEtcPath() + "/hg-ssh-wrapper"

    keydirs = [paths.getEtcPath() + "/keys", pentry.pw_dir + "/repos/hgadmin/keys"]

    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 keyroot in keydirs:

        kr = keyroot + "/"

        #print "Processing keyroot", keyroot

        for root, dirs, files in os.walk(keyroot):

            for fn in files:

                ffn = os.path.join(root, fn)

                if not ffn.startswith(kr):

                    raise Exception("Inconsistent behaviour in os.walk, bailing")

                #print "Processing file", ffn

                keyname = ffn[len(kr):]

                if not ruleset.goodpath(keyname):

                    # ignore any path that contains dodgy characters

                    #print "Ignoring file", ffn

                    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)