freeipa/ipapython/nsslib.py
Rob Crittenden b7ca3d68c2 Drop our own PKCS#10 ASN.1 decoder and use the one from python-nss
This patch:
- bumps up the minimum version of python-nss
- will initialize NSS with nodb if a CSR is loaded and it isn't already
  init'd
- will shutdown NSS if initialized in the RPC subsystem so we use right db
- updated and added a few more tests

Relying more on NSS introduces a bit of a problem. For NSS to work you
need to have initialized a database (either a real one or no_db). But once
you've initialized one and want to use another you have to close down the
first one.  I've added some code to nsslib.py to do just that. This could
potentially have some bad side-effects at some point, it works ok now.
2010-07-29 10:50:10 -04:00

252 lines
9.4 KiB
Python

# Authors: Rob Crittenden <rcritten@redhat.com>
# John Dennis <jdennis@redhat.com>
#
# Copyright (C) 2009 Red Hat
# see file 'COPYING' for use and warranty information
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation; version 2 only
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
import httplib
import getpass
import logging
from nss.error import NSPRError
import nss.io as io
import nss.nss as nss
import nss.ssl as ssl
def auth_certificate_callback(sock, check_sig, is_server, certdb):
cert_is_valid = False
cert = sock.get_peer_certificate()
logging.debug("auth_certificate_callback: check_sig=%s is_server=%s\n%s",
check_sig, is_server, str(cert))
pin_args = sock.get_pkcs11_pin_arg()
if pin_args is None:
pin_args = ()
# Define how the cert is being used based upon the is_server flag. This may
# seem backwards, but isn't. If we're a server we're trying to validate a
# client cert. If we're a client we're trying to validate a server cert.
if is_server:
intended_usage = nss.certificateUsageSSLClient
else:
intended_usage = nss.certificateUsageSSLServer
try:
# If the cert fails validation it will raise an exception, the errno attribute
# will be set to the error code matching the reason why the validation failed
# and the strerror attribute will contain a string describing the reason.
approved_usage = cert.verify_now(certdb, check_sig, intended_usage, *pin_args)
except Exception, e:
logging.error('cert validation failed for "%s" (%s)', cert.subject, e.strerror)
cert_is_valid = False
return cert_is_valid
logging.debug("approved_usage = %s intended_usage = %s",
', '.join(nss.cert_usage_flags(approved_usage)),
', '.join(nss.cert_usage_flags(intended_usage)))
# Is the intended usage a proper subset of the approved usage
if approved_usage & intended_usage:
cert_is_valid = True
else:
cert_is_valid = False
# If this is a server, we're finished
if is_server or not cert_is_valid:
logging.debug('cert valid %s for "%s"', cert_is_valid, cert.subject)
return cert_is_valid
# Certificate is OK. Since this is the client side of an SSL
# connection, we need to verify that the name field in the cert
# matches the desired hostname. This is our defense against
# man-in-the-middle attacks.
hostname = sock.get_hostname()
try:
# If the cert fails validation it will raise an exception
cert_is_valid = cert.verify_hostname(hostname)
except Exception, e:
logging.error('failed verifying socket hostname "%s" matches cert subject "%s" (%s)',
hostname, cert.subject, e.strerror)
cert_is_valid = False
return cert_is_valid
logging.debug('cert valid %s for "%s"', cert_is_valid, cert.subject)
return cert_is_valid
def client_auth_data_callback(ca_names, chosen_nickname, password, certdb):
cert = None
if chosen_nickname:
try:
cert = nss.find_cert_from_nickname(chosen_nickname, password)
priv_key = nss.find_key_by_any_cert(cert, password)
return cert, priv_key
except NSPRError:
return False
else:
nicknames = nss.get_cert_nicknames(certdb, nss.SEC_CERT_NICKNAMES_USER)
for nickname in nicknames:
try:
cert = nss.find_cert_from_nickname(nickname, password)
if cert.check_valid_times():
if cert.has_signer_in_ca_names(ca_names):
priv_key = nss.find_key_by_any_cert(cert, password)
return cert, priv_key
except NSPRError:
return False
return False
class NSSConnection(httplib.HTTPConnection):
default_port = httplib.HTTPSConnection.default_port
def __init__(self, host, port=None, strict=None, dbdir=None):
httplib.HTTPConnection.__init__(self, host, port, strict)
if not dbdir:
raise RuntimeError("dbdir is required")
logging.debug('%s init %s', self.__class__.__name__, host)
if nss.nss_is_initialized():
# close any open NSS database and use the new one
ssl.clear_session_cache()
nss.nss_shutdown()
nss.nss_init(dbdir)
ssl.set_domestic_policy()
nss.set_password_callback(self.password_callback)
# Create the socket here so we can do things like let the caller
# override the NSS callbacks
self.sock = ssl.SSLSocket()
self.sock.set_ssl_option(ssl.SSL_SECURITY, True)
self.sock.set_ssl_option(ssl.SSL_HANDSHAKE_AS_CLIENT, True)
# Provide a callback which notifies us when the SSL handshake is complete
self.sock.set_handshake_callback(self.handshake_callback)
# Provide a callback to verify the servers certificate
self.sock.set_auth_certificate_callback(auth_certificate_callback,
nss.get_default_certdb())
def password_callback(self, slot, retry, password):
if not retry and password: return password
return getpass.getpass("Enter password for %s: " % slot.token_name);
def handshake_callback(self, sock):
"""
Verify callback. If we get here then the certificate is ok.
"""
logging.debug("handshake complete, peer = %s", sock.get_peer_name())
pass
def connect(self):
logging.debug("connect: host=%s port=%s", self.host, self.port)
self.sock.set_hostname(self.host)
net_addr = io.NetworkAddress(self.host, self.port)
logging.debug("connect: %s", net_addr)
self.sock.connect(net_addr)
class NSSHTTPS(httplib.HTTP):
# We would like to use HTTP 1.1 not the older HTTP 1.0 but xmlrpclib
# and httplib do not play well together. httplib when the protocol
# is 1.1 will add a host header in the request. But xmlrpclib
# always adds a host header irregardless of the HTTP protocol
# version. That means the request ends up with 2 host headers,
# but Apache freaks out if it sees 2 host headers, a known Apache
# issue. httplib has a mechanism to skip adding the host header
# (i.e. skip_host in HTTPConnection.putrequest()) but xmlrpclib
# doesn't use it. Oh well, back to 1.0 :-(
#
#_http_vsn = 11
#_http_vsn_str = 'HTTP/1.1'
_connection_class = NSSConnection
def __init__(self, host='', port=None, strict=None, dbdir=None):
# provide a default host, pass the X509 cert info
# urf. compensate for bad input.
if port == 0:
port = None
self._setup(self._connection_class(host, port, strict, dbdir=dbdir))
class NSPRConnection(httplib.HTTPConnection):
default_port = httplib.HTTPConnection.default_port
def __init__(self, host, port=None, strict=None):
httplib.HTTPConnection.__init__(self, host, port, strict)
logging.debug('%s init %s', self.__class__.__name__, host)
self.sock = io.Socket()
def connect(self):
logging.debug("connect: host=%s port=%s", self.host, self.port)
net_addr = io.NetworkAddress(self.host, self.port)
logging.debug("connect: %s", net_addr)
self.sock.connect(net_addr)
class NSPRHTTP(httplib.HTTP):
_http_vsn = 11
_http_vsn_str = 'HTTP/1.1'
_connection_class = NSPRConnection
#------------------------------------------------------------------------------
if __name__ == "__main__":
logging.basicConfig(level=logging.DEBUG,
format='%(asctime)s %(levelname)-8s %(message)s',
datefmt='%m-%d %H:%M',
filename='nsslib.log',
filemode='a')
# Create a seperate logger for the console
console_logger = logging.StreamHandler()
console_logger.setLevel(logging.DEBUG)
# set a format which is simpler for console use
formatter = logging.Formatter('%(levelname)s %(message)s')
console_logger.setFormatter(formatter)
# add the handler to the root logger
logging.getLogger('').addHandler(console_logger)
logging.info("Start")
if False:
conn = NSSConnection("www.verisign.com", 443, dbdir="/etc/pki/nssdb")
conn.set_debuglevel(1)
conn.connect()
conn.request("GET", "/")
response = conn.getresponse()
print response.status
#print response.msg
print response.getheaders()
data = response.read()
#print data
conn.close()
if True:
h = NSSHTTPS("www.verisign.com", 443, dbdir="/etc/pki/nssdb")
h.connect()
h.putrequest('GET', '/')
h.endheaders()
http_status, http_reason, headers = h.getreply()
print "status = %s %s" % (http_status, http_reason)
print "headers:\n%s" % headers
f = h.getfile()
data = f.read() # Get the raw HTML
f.close()
#print data