"""
Trivial RPKI up-down protocol root server, for testing.  Not suitable
for production use.  Overrides a bunch of method definitions from the
rpki.* classes in order to reuse as much code as possible.

Usage: python rootd.py [ { -c | --config } configfile ] [ { -h | --help } ]

Default configuration file is rootd.conf, override with --config option.

$Id$

Copyright (C) 2009  Internet Systems Consortium ("ISC")

Permission to use, copy, modify, and distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.

Portions copyright (C) 2007--2008  American Registry for Internet Numbers ("ARIN")

Permission to use, copy, modify, and distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND ARIN DISCLAIMS ALL WARRANTIES WITH
REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS.  IN NO EVENT SHALL ARIN BE LIABLE FOR ANY SPECIAL, DIRECT,
INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.
"""

import os, time, getopt, sys
import rpki.resource_set, rpki.up_down, rpki.left_right, rpki.x509
import rpki.https, rpki.config, rpki.exceptions, rpki.relaxng
import rpki.sundial, rpki.log

rpki_root_cert = None

def get_root_cert():
  global rpki_root_cert
  rpki.log.debug("Read root cert %s" % rpki_root_cert_file)
  rpki_root_cert = rpki.x509.X509(Auto_file = rpki_root_cert_file)

def root_newer_than_subject():
  return os.stat(rpki_root_cert_file).st_mtime > os.stat(rpki_root_dir + rpki_subject_cert).st_mtime

def get_subject_cert():
  filename = rpki_root_dir + rpki_subject_cert
  try:
    x = rpki.x509.X509(Auto_file = filename)
    rpki.log.debug("Read subject cert %s" % filename)
    return x
  except IOError:
    return None

def set_subject_cert(cert):
  filename = rpki_root_dir + rpki_subject_cert
  rpki.log.debug("Writing subject cert %s, SKI %s" % (filename, cert.hSKI()))
  f = open(filename, "wb")
  f.write(cert.get_DER())
  f.close()

def del_subject_cert():
  filename = rpki_root_dir + rpki_subject_cert
  rpki.log.debug("Deleting subject cert %s" % filename)
  os.remove(filename)

def get_subject_pkcs10():
  try:
    x = rpki.x509.PKCS10(Auto_file = rpki_subject_pkcs10)
    rpki.log.debug("Read subject PKCS #10 %s" % rpki_subject_pkcs10)
    return x
  except IOError:
    return None

def set_subject_pkcs10(pkcs10):
  rpki.log.debug("Writing subject PKCS #10 %s" % rpki_subject_pkcs10)
  f = open(rpki_subject_pkcs10, "wb")
  f.write(pkcs10.get_DER())
  f.close()

def del_subject_pkcs10():
  rpki.log.debug("Deleting subject PKCS #10 %s" % rpki_subject_pkcs10)
  try:
    os.remove(rpki_subject_pkcs10)
  except OSError:
    pass
  
def issue_subject_cert_maybe(new_pkcs10):
  now = rpki.sundial.now()
  subject_cert = get_subject_cert()
  old_pkcs10 = get_subject_pkcs10()
  if new_pkcs10 is not None and new_pkcs10 != old_pkcs10:
    set_subject_pkcs10(new_pkcs10)
    if subject_cert is not None:
      rpki.log.debug("PKCS #10 changed, regenerating subject certificate")
      subject_cert = None
  if subject_cert is not None and subject_cert.getNotAfter() <= now + rpki_subject_regen:
    rpki.log.debug("Subject certificate has reached expiration threshold, regenerating")
    subject_cert = None
  if subject_cert is not None and root_newer_than_subject():
    rpki.log.debug("Root certificate has changed, regenerating subject")
    subject_cert = None
  get_root_cert()
  if subject_cert is not None:
    return subject_cert
  pkcs10 = old_pkcs10 if new_pkcs10 is None else new_pkcs10
  if pkcs10 is None:
    rpki.log.debug("No PKCS #10 request, can't generate subject certificate yet")
    return None
  resources = rpki_root_cert.get_3779resources()
  rpki.log.info("Generating subject cert with resources " + str(resources))
  req_key = pkcs10.getPublicKey()
  req_sia = pkcs10.get_SIA()
  crldp = rpki_base_uri + rpki_root_crl
  serial = now.totimestamp()
  subject_cert = rpki_root_cert.issue(
    keypair     = rpki_root_key,
    subject_key = req_key,
    serial      = serial,
    sia         = req_sia,
    aia         = rpki_root_cert_uri,
    crldp       = crldp,
    resources   = resources,
    notAfter    = now + rpki_subject_lifetime)
  crl = rpki.x509.CRL.generate(
    keypair             = rpki_root_key,
    issuer              = rpki_root_cert,
    serial              = serial,
    thisUpdate          = now,
    nextUpdate          = now + rpki_subject_lifetime,
    revokedCertificates = ())
  rpki.log.debug("Writing CRL %s" % (rpki_root_dir + rpki_root_crl))
  f = open(rpki_root_dir + rpki_root_crl, "wb")
  f.write(crl.get_DER())
  f.close()
  manifest_resources = rpki.resource_set.resource_bag(
    asn = rpki.resource_set.resource_set_as(rpki.resource_set.inherit_token),
    v4 = rpki.resource_set.resource_set_ipv4(rpki.resource_set.inherit_token),
    v6 = rpki.resource_set.resource_set_ipv6(rpki.resource_set.inherit_token))
  manifest_keypair = rpki.x509.RSA.generate()
  manifest_cert = rpki_root_cert.issue(
    keypair     = rpki_root_key,
    subject_key = manifest_keypair.get_RSApublic(),
    serial      = serial + 1,
    sia         = None,
    aia         = rpki_root_cert_uri,
    crldp       = crldp,
    resources   = manifest_resources,
    notAfter    = now + rpki_subject_lifetime,
    is_ca       = False)
  manifest = rpki.x509.SignedManifest.build(
    serial         = serial,
    thisUpdate     = now,
    nextUpdate     = now + rpki_subject_lifetime,
    names_and_objs = [(rpki_subject_cert, subject_cert), (rpki_root_crl, crl)],
    keypair        = manifest_keypair,
    certs          = manifest_cert)
  rpki.log.debug("Writing manifest %s" % (rpki_root_dir + rpki_root_manifest))
  f = open(rpki_root_dir + rpki_root_manifest, "wb")
  f.write(manifest.get_DER())
  f.close()
  set_subject_cert(subject_cert)
  return subject_cert

def compose_response(r_msg, pkcs10 = None):
  subject_cert = issue_subject_cert_maybe(pkcs10)
  rc = rpki.up_down.class_elt()
  rc.class_name = rpki_class_name
  rc.cert_url = rpki.up_down.multi_uri(rpki_root_cert_uri)
  rc.from_resource_bag(rpki_root_cert.get_3779resources())
  rc.issuer = rpki_root_cert
  r_msg.payload.classes.append(rc)
  if subject_cert is not None:
    rc.certs.append(rpki.up_down.certificate_elt())
    rc.certs[0].cert_url = rpki.up_down.multi_uri(rpki_base_uri + rpki_subject_cert)
    rc.certs[0].cert = subject_cert

class list_pdu(rpki.up_down.list_pdu):
  def serve_pdu(self, q_msg, r_msg, ignored, callback, errback):
    r_msg.payload = rpki.up_down.list_response_pdu()
    compose_response(r_msg)
    callback()

class issue_pdu(rpki.up_down.issue_pdu):
  def serve_pdu(self, q_msg, r_msg, ignored, callback, errback):
    self.pkcs10.check_valid_rpki()
    r_msg.payload = rpki.up_down.issue_response_pdu()
    compose_response(r_msg, self.pkcs10)
    callback()

class revoke_pdu(rpki.up_down.revoke_pdu):
  def serve_pdu(self, q_msg, r_msg, ignored, callback, errback):
    subject_cert = get_subject_cert()
    if subject_cert is None or subject_cert.gSKI() != self.ski:
      raise rpki.exceptions.NotInDatabase
    del_subject_cert()
    del_subject_pkcs10()
    r_msg.payload = rpki.up_down.revoke_response_pdu()
    r_msg.payload.class_name = self.class_name
    r_msg.payload.ski = self.ski
    callback()

class message_pdu(rpki.up_down.message_pdu):

  name2type = {
    "list"            : list_pdu,
    "list_response"   : rpki.up_down.list_response_pdu,
    "issue"           : issue_pdu,
    "issue_response"  : rpki.up_down.issue_response_pdu,
    "revoke"          : revoke_pdu,
    "revoke_response" : rpki.up_down.revoke_response_pdu,
    "error_response"  : rpki.up_down.error_response_pdu }

  type2name = dict((v, k) for k, v in name2type.items())

  def log_query(self, child):
    """
    Log query we're handling.
    """
    rpki.log.info("Serving %s query" % self.type)

class sax_handler(rpki.up_down.sax_handler):
  pdu = message_pdu

class cms_msg(rpki.up_down.cms_msg):
  saxify = sax_handler.saxify

def up_down_handler(query, path, cb):
  try:
    q_msg = cms_msg.unwrap(query, (bpki_ta, child_bpki_cert))
  except (rpki.async.ExitNow, SystemExit):
    raise
  except Exception, data:
    rpki.log.traceback()
    return cb(400, "Could not process PDU: %s" % data)

  def done(r_msg):
    r_cms = cms_msg.wrap(r_msg, rootd_bpki_key, rootd_bpki_cert, rootd_bpki_crl)
    cb(200, r_cms)

  try:
    q_msg.serve_top_level(None, done)
  except (rpki.async.ExitNow, SystemExit):
    raise
  except Exception, data:
    rpki.log.traceback()
    try:
      done(q_msg.serve_error(data))
    except (rpki.async.ExitNow, SystemExit):
      raise
    except Exception, data:
      rpki.log.traceback()
      cb(500, "Could not process PDU: %s" % data)

os.environ["TZ"] = "UTC"
time.tzset()

cfg_file = "rootd.conf"

opts, argv = getopt.getopt(sys.argv[1:], "c:dh?", ["config=", "debug", "help"])
for o, a in opts:
  if o in ("-h", "--help", "-?"):
    print __doc__
    sys.exit(0)
  elif o in ("-c", "--config"):
    cfg_file = a
  elif o in ("-d", "--debug"):
    rpki.log.use_syslog = False
if argv:
  raise RuntimeError, "Unexpected arguments %s" % argv

rpki.log.init("rootd")

cfg = rpki.config.parser(cfg_file, "rootd")

cfg.set_global_flags()

bpki_ta                 = rpki.x509.X509(Auto_file = cfg.get("bpki-ta"))
rootd_bpki_key          = rpki.x509.RSA( Auto_file = cfg.get("rootd-bpki-key"))
rootd_bpki_cert         = rpki.x509.X509(Auto_file = cfg.get("rootd-bpki-cert"))
rootd_bpki_crl          = rpki.x509.CRL( Auto_file = cfg.get("rootd-bpki-crl"))
child_bpki_cert         = rpki.x509.X509(Auto_file = cfg.get("child-bpki-cert"))

https_server_host       = cfg.get("server-host", "")
https_server_port       = int(cfg.get("server-port"))

rpki_class_name         = cfg.get("rpki-class-name", "wombat")

rpki_root_dir           = cfg.get("rpki-root-dir")
rpki_base_uri           = cfg.get("rpki-base-uri", "rsync://" + rpki_class_name + ".invalid/")

rpki_root_key           = rpki.x509.RSA( Auto_file = cfg.get("rpki-root-key"))
rpki_root_cert_file     = cfg.get("rpki-root-cert")
rpki_root_cert_uri      = cfg.get("rpki-root-cert-uri", rpki_base_uri + "Root.cer")

rpki_root_manifest      = cfg.get("rpki-root-manifest", "Root.mnf")
rpki_root_crl           = cfg.get("rpki-root-crl",      "Root.crl")
rpki_subject_cert       = cfg.get("rpki-subject-cert",  "Child.cer")
rpki_subject_pkcs10     = cfg.get("rpki-subject-pkcs10", "Child.pkcs10")

rpki_subject_lifetime   = rpki.sundial.timedelta.parse(cfg.get("rpki-subject-lifetime", "30d"))
rpki_subject_regen      = rpki.sundial.timedelta.parse(cfg.get("rpki-subject-regen", rpki_subject_lifetime.convert_to_seconds() / 2))

rpki.https.server(server_key   = rootd_bpki_key,
                  server_cert  = rootd_bpki_cert,
                  client_ta    = (bpki_ta, child_bpki_cert),
                  host         = https_server_host,
                  port         = https_server_port,
                  handlers     = up_down_handler)