/
swede
executable file
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/
swede
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#!/usr/bin/python
# swede - A tool to create DANE/TLSA records.
# This tool is really simple and not foolproof, it doesn't check the CN in the
# Subject field of the certificate. It also doesn't check if the supplied
# certificate is a CA certificate if usage 1 is specified (or any other
# checking for that matter).
#
# Usage is explained when running this program with --help
#
# This tool is loosly based on the dane tool in the sshfp package by Paul
# Wouters and Christopher Olah from xelerance.com.
#
# Copyright Pieter Lexis (pieter.lexis@os3.nl)
#
# License: GNU GENERAL PUBLIC LICENSE Version 2 or later
import sys
import os
import socket
import smtplib
import imaplib
import poplib
import unbound
import re
from M2Crypto import X509, SSL
from binascii import a2b_hex, b2a_hex
from hashlib import sha256, sha512
from ipaddr import IPv4Address, IPv6Address
def genTLSA(hostname, protocol, port, certificate, output='generic', usage=1, selector=0, mtype=1):
"""This function generates a TLSARecord object using the data passed in the parameters,
it then validates the record and returns the RR as a string.
"""
# check if valid vars were passed
if hostname[-1] != '.':
hostname += '.'
certificate = loadCert(certificate)
if not certificate:
raise Exception('Cannot load certificate from disk')
# Create the record without a certificate
if port == '*':
record = TLSARecord(name='%s._%s.%s'%(port,protocol,hostname), usage=usage, selector=selector, mtype=mtype, cert ='')
else:
record = TLSARecord(name='_%s._%s.%s'%(port,protocol,hostname), usage=usage, selector=selector, mtype=mtype, cert ='')
# Check if the record is valid
if record.isValid:
if record.selector == 0:
# Hash the Full certificate
record.cert = getHash(certificate, record.mtype)
else:
# Hash only the SubjectPublicKeyInfo
record.cert = getHash(certificate.get_pubkey(), record.mtype)
record.isValid(raiseException=True)
if output == 'generic':
return record.getRecord(generic=True)
return record.getRecord()
def getA(hostname, secure=True):
"""Gets a list of A records for hostname, returns a list of ARecords"""
try:
records = getRecords(hostname, rrtype='A', secure=secure)
except InsecureLookupException, e:
print str(e)
sys.exit(1)
except DNSLookupError, e:
print 'Unable to resolve %s: %s' % (hostname, str(e))
sys.exit(1)
ret = []
for record in records:
ret.append(ARecord(hostname, str(IPv4Address(int(b2a_hex(record),16)))))
return ret
def getAAAA(hostname, secure=True):
"""Gets a list of A records for hostname, returns a list of AAAARecords"""
try:
records = getRecords(hostname, rrtype='AAAA', secure=secure)
except InsecureLookupException, e:
print str(e)
sys.exit(1)
except DNSLookupError, e:
print 'Unable to resolve %s: %s' % (hostname, str(e))
sys.exit(1)
ret = []
for record in records:
ret.append(AAAARecord(hostname, str(IPv6Address(int(b2a_hex(record),16)))))
return ret
def getVerificationErrorReason(num):
"""This function returns the name of the X509 Error based on int(num)
"""
# These were taken from the M2Crypto.m2 code
return {
50: "X509_V_ERR_APPLICATION_VERIFICATION",
22: "X509_V_ERR_CERT_CHAIN_TOO_LONG",
10: "X509_V_ERR_CERT_HAS_EXPIRED",
9: "X509_V_ERR_CERT_NOT_YET_VALID",
28: "X509_V_ERR_CERT_REJECTED",
23: "X509_V_ERR_CERT_REVOKED",
7: "X509_V_ERR_CERT_SIGNATURE_FAILURE",
27: "X509_V_ERR_CERT_UNTRUSTED",
12: "X509_V_ERR_CRL_HAS_EXPIRED",
11: "X509_V_ERR_CRL_NOT_YET_VALID",
8: "X509_V_ERR_CRL_SIGNATURE_FAILURE",
18: "X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT",
14: "X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD",
13: "X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD",
15: "X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD",
16: "X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD",
24: "X509_V_ERR_INVALID_CA",
26: "X509_V_ERR_INVALID_PURPOSE",
17: "X509_V_ERR_OUT_OF_MEM",
25: "X509_V_ERR_PATH_LENGTH_EXCEEDED",
19: "X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN",
6: "X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY",
4: "X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE",
5: "X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE",
3: "X509_V_ERR_UNABLE_TO_GET_CRL",
2: "X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT",
20: "X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY",
21: "X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE",
0: "X509_V_OK"}[int(num)]
def getRecords(hostname, rrtype='A', secure=True):
"""Do a lookup of a name and a rrtype, returns a list of binary coded strings. Only queries for rr_class IN."""
global resolvconf
global trust_anchor_file
ctx = unbound.ub_ctx()
ctx.add_ta_file(os.path.dirname(os.path.realpath(__file__))+'/root.key')
ctx.set_option("dlv-anchor-file:", os.path.dirname(os.path.realpath(__file__))+"/dlv.isc.org.key")
# Use the local cache
if resolvconf:
ctx.resolvconf(resolvconf)
# Use an optional trust-anchor file
if trust_anchor_file:
ctx.set_option("trust-anchor-file:", trust_anchor_file)
if type(rrtype) == str:
if 'RR_TYPE_' + rrtype in dir(unbound):
rrtype = getattr(unbound, 'RR_TYPE_' + rrtype)
else:
raise Exception('Error: unknown RR TYPE: %s.' % rrtype)
elif type(rrtype) != int:
raise Exception('Error: rrtype in wrong format, neither int nor str.')
status, result = ctx.resolve(hostname, rrtype=rrtype)
if status == 0:
if not result.havedata:
return []
if not result.secure:
if secure:
# The data is insecure and a secure lookup was requested
raise InsecureLookupException('Error: query data not secure and secure data requested, unable to continue')
else:
print >> sys.stderr, 'Warning: query data is not secure.'
# If we are here the data was either secure or insecure data is accepted
return result.data.raw
else:
raise DNSLookupError('Unsuccesful lookup or no data returned for rrtype %s.' % rrtype)
def getHash(certificate, mtype):
"""Hashes the certificate based on the mtype.
The certificate should be an M2Crypto.X509.X509 object (or the result of the get_pubkey() function on said object)
"""
certificate = certificate.as_der()
if mtype == 0:
return b2a_hex(certificate)
elif mtype == 1:
return sha256(certificate).hexdigest()
elif mtype == 2:
return sha512(certificate).hexdigest()
else:
raise Exception('mtype should be 0,1,2')
def getTLSA(hostname, port=443, protocol='tcp', secure=True):
"""
This function tries to do a secure lookup of the TLSA record.
At the moment it requests the TYPE52 record and parses it into a 'valid' TLSA record
It returns a list of TLSARecord objects
"""
if hostname[-1] != '.':
hostname += '.'
if not protocol.lower() in ['tcp', 'udp', 'sctp']:
raise Exception('Error: unknown protocol: %s. Should be one of tcp, udp or sctp' % protocol)
try:
if port == '*':
records = getRecords('*._%s.%s' % (protocol.lower(), hostname), rrtype=52, secure=secure)
else:
records = getRecords('_%s._%s.%s' % (port, protocol.lower(), hostname), rrtype=52, secure=secure)
except InsecureLookupException, e:
print str(e)
sys.exit(1)
except DNSLookupError, e:
print 'Unable to resolve %s: %s' % (hostname, str(e))
sys.exit(1)
ret = []
for record in records:
hexdata = b2a_hex(record)
if port == '*':
ret.append(TLSARecord('*._%s.%s' % (protocol.lower(), hostname), int(hexdata[0:2],16), int(hexdata[2:4],16), int(hexdata[4:6],16), hexdata[6:]))
else:
ret.append(TLSARecord('_%s._%s.%s' % (port, protocol.lower(), hostname), int(hexdata[0:2],16), int(hexdata[2:4],16), int(hexdata[4:6],16), hexdata[6:]))
return ret
def loadCert(certificate):
"""Returns an M2Crypto.X509.X509 object"""
if isinstance(certificate, X509.X509):
# nothing to be done :-)
return certificate
try:
# Maybe we were passed a path
return X509.load_cert(certificate)
except:
# Can't load the cert
raise Exception('Unable to load certificate %s.' % certificate)
def verifyCertMatch(record, cert):
"""
Verify the certificate with the record.
record should be a TLSARecord and cert should be a M2Crypto.X509.X509
"""
if not isinstance(cert, X509.X509):
return
if not isinstance(record, TLSARecord):
return
if record.selector == 1:
certhash = getHash(cert.get_pubkey(), record.mtype)
else:
certhash = getHash(cert, record.mtype)
if not certhash:
return
if certhash == record.cert:
return True
else:
return False
def verifyCertNameWithHostName(cert, hostname, with_msg=False):
"""Verify the name on the certificate with a hostname, we need this because we get the cert based on IP address and thusly cannot rely on M2Crypto to verify this"""
if not isinstance(cert, X509.X509):
return
if not isinstance(hostname, str):
return
if hostname[-1] == '.':
hostname = hostname[0:-1]
# Ugly string comparison to see if the name on the ee-cert matches with the name provided on the commandline
try:
altnames_on_cert = cert.get_ext('subjectAltName').get_value()
except:
altnames_on_cert = ''
# Build a list containing the CN and all the SANs
dns_names = [ str(cert.get_subject().commonName) ]
p = re.compile(r'DNS:([^,]+),?')
for dns_name in p.findall(altnames_on_cert):
dns_names.append(p.sub(r'\1', dns_name))
# Compare the CN/SANs list with the hostname with wildcard matching
for dns_name in dns_names:
if re.match('^' + dns_name.replace('*', '\\w[\w\d-]*').replace('.','\.') + '$', hostname):
return True
if with_msg:
print 'WARNING: Name on the certificate (Subject: %s, SubjectAltName: %s) doesn\'t match requested hostname (%s).' % (cert.get_subject(), altnames_on_cert, hostname)
return False
class TLSARecord:
"""When instanciated, this class contains all the fields of a TLSA record.
"""
def __init__(self, name, usage, selector, mtype, cert):
"""name is the name of the RR in the format: /^(_\d{1,5}|\*)\._(tcp|udp|sctp)\.([a-z0-9]*\.){2,}$/
usage, selector and mtype should be an integer
cert should be a hexidecimal string representing the certificate to be matched field
"""
try:
self.rrtype = 52 # TLSA per https://www.iana.org/assignments/dns-parameters
self.rrclass = 1 # IN
self.name = str(name)
self.usage = int(usage)
self.selector = int(selector)
self.mtype = int(mtype)
self.cert = str(cert)
except:
raise Exception('Invalid value passed, unable to create a TLSARecord')
def getRecord(self, generic=False):
"""Returns the RR string of this TLSARecord, either in rfc (default) or generic format"""
if generic:
return '%s IN TYPE52 \# %s %s%s%s%s' % (self.name, (len(self.cert)/2)+3 , self._toHex(self.usage), self._toHex(self.selector), self._toHex(self.mtype), self.cert)
return '%s IN TLSA %s %s %s %s' % (self.name, self.usage, self.selector, self.mtype, self.cert)
def _toHex(self, val):
"""Helper function to create hex strings from integers"""
return "%0.2x" % val
def isValid(self, raiseException=False):
"""Check whether all fields in the TLSA record are conforming to the spec and check if the port, protocol and name are good"""
err =[]
try:
if not 1 <= int(self.getPort()) <= 65535:
err.append('Port %s not within correct range (1 <= port <= 65535)' % self.getPort())
except:
if self.getPort() != '*':
err.append('Port %s not a number' % self.getPort())
if not self.usage in [0,1,2,3]:
err.append('Usage: invalid (%s is not one of 0, 1, 2 or 3)' % self.usage)
if not self.selector in [0,1]:
err.append('Selector: invalid (%s is not one of 0 or 1)' % self.selector)
if not self.mtype in [0,1,2]:
err.append('Matching Type: invalid (%s is not one of 0, 1 or 2)' % self.mtype)
if not self.isNameValid():
err.append('Name (%s) is not in the correct format: _portnumber._transportprotocol.hostname.dom.' % self.name)
# A certificate length of 0 is accepted
if self.mtype in [1,2] and len(self.cert) != 0:
if not len(self.cert) == {1:64,2:128}[self.mtype]:
err.append('Certificate for Association: invalid (Hash length does not match hash-type in Matching Type(%s))' % {1:'SHA-256',2:'SHA-512'}[self.mtype])
if len(err) != 0:
if not raiseException:
return False
else:
msg = 'The TLSA record is invalid.'
for error in err:
msg += '\n\t%s' % error
raise RecordValidityException(msg)
else:
return True
def isNameValid(self):
"""Check if the name if in the correct format"""
if not re.match('^(_\d{1,5}|\*)\._(tcp|udp|sctp)\.([-a-z0-9]*\.){2,}$', self.name):
return False
return True
def getProtocol(self):
"""Returns the protocol based on the name"""
return re.split('\.', self.name)[1][1:]
def getPort(self):
"""Returns the port based on the name"""
if re.split('\.', self.name)[0][0] == '*':
return '*'
else:
return re.split('\.', self.name)[0][1:]
class ARecord:
"""An object representing an A Record (IPv4 address)"""
def __init__(self, hostname, address):
self.rrtype = 1
self.hostname = hostname
self.address = address
def __str__(self):
return self.address
def isValid(self):
try:
IPv4Address(self.address)
return True
except:
return False
class AAAARecord:
"""An object representing an AAAA Record (IPv6 address)"""
def __init__(self, hostname, address):
self.rrtype = 28
self.hostname = hostname
self.address = address
def __str__(self):
return self.address
def isValid(self):
try:
IPv6Address(self.address)
return True
except:
return False
# Exceptions
class RecordValidityException(Exception):
pass
class InsecureLookupException(Exception):
pass
class DNSLookupError(Exception):
pass
class StartTLSConnection(SSL.Connection):
"""Subclass allowing to issue StartTLS command before establishing TLS connection"""
def connect(self, addr, starttls='none'):
self.socket.connect(addr)
self.addr = addr
if starttls == "smtp":
self.starttls_smtp()
elif starttls == "imap":
self.starttls_imap()
elif starttls == "pop3":
self.starttls_pop3()
elif starttls != "none":
raise SSL.Checker.SSLVerificationError, 'StartTLS not supported for given protocol'
self.setup_ssl()
self.set_connect_state()
ret = self.connect_ssl()
check = getattr(self, 'postConnectionCheck', self.clientPostConnectionCheck)
if check is not None:
if not check(self.get_peer_cert(), self.addr[0]):
raise SSL.Checker.SSLVerificationError, 'post connection check failed'
return ret
def starttls_smtp(self):
socket = self.socket
class MySMTP(smtplib.SMTP):
def _get_socket(self, host, port, timeout):
return socket
smtp = MySMTP()
smtp.connect()
smtp.ehlo_or_helo_if_needed()
if not smtp.has_extn("starttls"):
raise smtplib.SMTPException("STARTTLS extension not supported by server.")
(resp, reply) = smtp.docmd("STARTTLS")
if resp != 220:
raise smtplib.SMTPException("STARTTLS command failed.")
def starttls_imap(self):
# StartTLS command is not supported until Python 3.2
imaplib.Commands['STARTTLS'] = ('NONAUTH',)
socket = self.socket
class MyIMAP(imaplib.IMAP4):
def open(self, host, port):
self.host = host
self.port = port
self.sock = socket
self.file = self.sock.makefile('rb')
def starttls(self):
name = 'STARTTLS'
if name not in self.capabilities:
raise self.abort('TLS not supported by server')
typ, dat = self._simple_command(name)
if typ != 'OK':
raise self.error("Couldn't establish TLS session")
imap = MyIMAP()
imap.starttls()
def starttls_pop3(self):
# StartTLS command is not supported until Python 3.4
socket = self.socket
class MyPOP3(poplib.POP3):
def __init__(self):
self.host = ""
self.port = 143
self.sock = socket
self.file = self.sock.makefile('rb')
self._debugging = 0
self.welcome = self._getresp()
def capa(self):
"""Return server capabilities (RFC 2449) as a dictionary
>>> c=poplib.POP3('localhost')
>>> c.capa()
{'IMPLEMENTATION': ['Cyrus', 'POP3', 'server', 'v2.2.12'],
'TOP': [], 'LOGIN-DELAY': ['0'], 'AUTH-RESP-CODE': [],
'EXPIRE': ['NEVER'], 'USER': [], 'STLS': [], 'PIPELINING': [],
'UIDL': [], 'RESP-CODES': []}
>>>
Really, according to RFC 2449, the cyrus folks should avoid
having the implementation split into multiple arguments...
"""
def _parsecap(line):
lst = line.decode('ascii').split()
return lst[0], lst[1:]
caps = {}
try:
resp = self._longcmd('CAPA')
rawcaps = resp[1]
for capline in rawcaps:
capnm, capargs = _parsecap(capline)
caps[capnm] = capargs
except poplib.error_proto:
raise poplib.error_proto('-ERR CAPA not supported by server')
return caps
def stls(self, context=None):
caps = self.capa()
if not 'STLS' in caps:
raise poplib.error_proto('-ERR STLS not supported by server')
resp = self._shortcmd('STLS')
return resp
pop3 = MyPOP3()
pop3.stls()
if __name__ == '__main__':
import argparse
# create the parser
parser = argparse.ArgumentParser(description='Create and verify DANE records.', epilog='This tool has a few limitations')
subparsers = parser.add_subparsers(title='Functions', help='Available functions, see %(prog)s function -h for function-specific help')
parser_verify = subparsers.add_parser('verify', help='Verify a TLSA record, exit 0 when all TLSA records are matched, exit 2 when a record does not match the received certificate, exit 1 on error.', epilog='Caveat: For TLSA validation, this program chases through the certificate chain offered by the server, not its local certificates.')
parser_verify.set_defaults(function='verify')
parser_create = subparsers.add_parser('create', help='Create a TLSA record')
parser_create.set_defaults(function='create')
parser.add_argument('-4', dest='ipv4', action='store_true',help='use ipv4 networking only')
parser.add_argument('-6', dest='ipv6', action='store_true',help='use ipv6 networking only')
parser.add_argument('--insecure', action='store_true', default=False, help='Allow use of non-dnssec secured answers')
parser.add_argument('--resolvconf', metavar='/PATH/TO/RESOLV.CONF', action='store', default='', help='Use a recursive resolver from resolv.conf')
parser.add_argument('--trust-anchor-file', metavar='/PATH/TO/TRUST-ANCHOR.KEY', action='store', default='', help='Path to a file containing additional trust anchor(s) for validation')
parser.add_argument('-v', '--version', action='version', version='%(prog)s v0.2', help='show version and exit')
parser.add_argument('--quiet', '-q', action='store_true', help='Only print the result of the creation / validation')
parser.add_argument('host', metavar="hostname")
parser_verify.add_argument('--port', '-p', action='store', default='443', help='The port, or \'*\' where running TLS is located (default: %(default)s).')
parser_verify.add_argument('--protocol', action='store', choices=['tcp','udp','sctp'], default='tcp', help='The protocol the TLS service is using (default: %(default)s).')
parser_verify.add_argument('--only-rr', '-o', action='store_true', help='Only verify that the TLSA resource record is correct (do not check certificate)')
parser_verify.add_argument('--ca-cert', metavar='/PATH/TO/CERTSTORE', action='store', default = '/etc/ssl/certs/', help='Path to a CA certificate or a directory containing the certificates (default: %(default)s)')
parser_verify.add_argument('--starttls', action='store', choices=['none','smtp','imap','pop3'], default='none', help='Issue StartTLS command before TLS handshake (default: %(default)s).')
parser_create.add_argument('--port', '-p', action='store', type=int, default=443, help='The port where running TLS is located (default: %(default)s).')
parser_create.add_argument('--protocol', action='store', choices=['tcp','udp','sctp'], default='tcp', help='The protocol the TLS service is using (default: %(default)s).')
parser_create.add_argument('--certificate', '-c', help='The certificate used for the host. If certificate is empty, the certificate will be downloaded from the server')
parser_create.add_argument('--output', '-o', action='store', default='generic', choices=['generic','rfc','both'], help='The type of output. Generic (RFC 3597, TYPE52), RFC (TLSA) or both (default: %(default)s).')
# Usage of the certificate
parser_create.add_argument('--usage', '-u', action='store', type=int, default=1, choices=[0,1,2,3], help='The Usage of the Certificate for Association. \'0\' for CA, \'1\' for End Entity, \'2\' for trust-anchor, \'3\' for ONLY End-Entity match (default: %(default)s).')
parser_create.add_argument('--selector', '-s', action='store', type=int, default=0, choices=[0,1], help='The Selector for the Certificate for Association. \'0\' for Full Certificate, \'1\' for SubjectPublicKeyInfo (default: %(default)s).')
parser_create.add_argument('--mtype', '-m', action='store', type=int, default=1, choices=[0,1,2], help='The Matching Type of the Certificate for Association. \'0\' for Exact match, \'1\' for SHA-256 hash, \'2\' for SHA-512 (default: %(default)s).')
parser_create.add_argument('--starttls', action='store', choices=['none','smtp','imap','pop3'], default='none', help='Issue StartTLS command before TLS handshake (default: %(default)s).')
args = parser.parse_args()
if args.host[-1] != '.':
args.host += '.'
global resolvconf
if args.resolvconf:
if os.path.isfile(args.resolvconf):
resolvconf = args.resolvconf
else:
print >> sys.stdout, '%s is not a file. Unable to use it as resolv.conf' % args.resolvconf
sys.exit(1)
else:
resolvconf = None
global trust_anchor_file
if args.trust_anchor_file:
if os.path.isfile(args.trust_anchor_file):
trust_anchor_file = args.trust_anchor_file
else:
print >> sys.stdout, '%s is not a file. Unable to use it as trust anchor file' % args.trust_anchor_file
sys.exit(1)
else:
trust_anchor_file = None
# not operations are fun!
secure = not args.insecure
if args.function == 'verify':
records = getTLSA(args.host, args.port, args.protocol, secure)
if len(records) == 0:
sys.exit(1)
for record in records:
pre_exit = 0
# First, check if the first three fields have correct values.
if not args.quiet:
print 'Received the following record for name %s:' % record.name
print '\tUsage:\t\t\t\t%d (%s)' % (record.usage, {0:'CA Constraint', 1:'End-Entity Constraint + chain to CA', 2:'Trust Anchor', 3:'End-Entity'}.get(record.usage, 'INVALID'))
print '\tSelector:\t\t\t%d (%s)' % (record.selector, {0:'Certificate', 1:'SubjectPublicKeyInfo'}.get(record.selector, 'INVALID'))
print '\tMatching Type:\t\t\t%d (%s)' % (record.mtype, {0:'Full Certificate', 1:'SHA-256', 2:'SHA-512'}.get(record.mtype, 'INVALID'))
print '\tCertificate for Association:\t%s' % record.cert
try:
record.isValid(raiseException=True)
except RecordValidityException, e:
print >> sys.stderr, 'Error: %s' % str(e)
continue
else:
if not args.quiet:
print 'This record is valid (well-formed).'
if args.only_rr:
# Go to the next record
continue
# When we are here, The user also wants to verify the certificates with the record
if args.protocol != 'tcp':
print >> sys.stderr, 'Only SSL over TCP is supported (sorry)'
sys.exit(0)
if not args.quiet:
print 'Attempting to verify the record with the TLS service...'
if args.ipv4:
addresses = getA(args.host, secure=secure)
elif args.ipv6:
addresses = getAAAA(args.host, secure=secure)
else:
addresses = getA(args.host, secure=secure) + getAAAA(args.host, secure=secure)
for address in addresses:
if not args.quiet:
print 'Got the following IP: %s' % str(address)
# We do the certificate handling here, as M2Crypto keeps segfaulting when we do it in a method
ctx = SSL.Context()
if os.path.isfile(args.ca_cert):
if ctx.load_verify_locations(cafile=args.ca_cert) != 1: raise Exception('No CA cert')
elif os.path.exists(args.ca_cert):
if ctx.load_verify_locations(capath=args.ca_cert) != 1: raise Exception('No CA certs')
else:
print >> sys.stderr, '%s is neither a file nor a directory, unable to continue' % args.ca_cert
sys.exit(1)
# Don't error when the verification fails in the SSL handshake
ctx.set_verify(SSL.verify_none, depth=9)
if isinstance(address, AAAARecord):
sock = socket.socket(socket.AF_INET6, socket.SOCK_STREAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
else:
sock = None
connection = StartTLSConnection(ctx, sock=sock)
# Try to use SNI for virtual hosts if available
try:
# We don't want the trailing dot here
connection.set_tlsext_host_name(args.host[:-1])
except AttributeError:
if not args.quiet: print >> sys.stderr, 'M2Crypto does not support SNI: services using virtual-hosting will show the wrong certificate!'
try:
connection.connect((str(address), int(args.port)), args.starttls)
except SSL.Checker.WrongHost, e:
# The name on the remote cert doesn't match the hostname because we connect on IP, not hostname (as we want secure lookup)
pass
except socket.error, e:
print 'Cannot connect to %s: %s' % (address, str(e))
continue
chain = connection.get_peer_cert_chain()
verify_result = connection.get_verify_result()
# Good, now let's verify
if record.usage != 3 and not verifyCertNameWithHostName(cert=chain[0], hostname=str(args.host), with_msg=True):
# The name on the cert doesn't match the hostname... we don't verify the TLSA record
print 'Not checking the TLSA record.'
continue
if record.usage == 1: # End-host cert
cert = chain[0]
if verifyCertMatch(record, cert):
if verify_result == 0: # The cert chains to a valid CA cert according to the system-certificates
print 'SUCCESS (Usage 1): Certificate offered by the server matches the one mentioned in the TLSA record and chains to a valid CA certificate'
else:
print 'FAIL (Usage 1): Certificate offered by the server matches the one mentioned in the TLSA record but the following error was raised during PKIX validation: %s' % getVerificationErrorReason(verify_result)
if pre_exit == 0: pre_exit = 2
if not args.quiet: print 'The matched certificate has Subject: %s' % cert.get_subject()
else:
print 'FAIL (Usage 1): Certificate offered by the server does not match the TLSA record'
if pre_exit == 0: pre_exit = 2
elif record.usage == 0: # CA constraint
matched = False
# Remove the first (= End-Entity cert) from the chain
chain = chain[1:]
for cert in chain:
if verifyCertMatch(record, cert):
matched = True
continue
if matched:
if cert.check_ca():
if verify_result == 0:
print 'SUCCESS (Usage 0): A certificate in the certificate chain offered by the server matches the one mentioned in the TLSA record and is a CA certificate'
else:
print 'FAIL (Usage 0): A certificate in the certificate chain offered by the server matches the one mentioned in the TLSA record and is a CA certificate, but the following error was raised during PKIX validation:' % getVerificationErrorReason(verify_result)
if pre_exit == 0: pre_exit = 2
else:
print 'FAIL (Usage 0): A certificate in the certificate chain offered by the server matches the one mentioned in the TLSA record but is not a CA certificate'
if pre_exit == 0: pre_exit = 2
if not args.quiet: print 'The matched certificate has Subject: %s' % cert.get_subject()
else:
print 'FAIL (Usage 0): No certificate in the certificate chain offered by the server matches the TLSA record'
if pre_exit == 0: pre_exit = 2
elif record.usage == 2: # Usage 2, use the cert in the record as trust anchor
#FIXME: doesnt comply to the spec
matched = False
previous_issuer = None
for cert in chain:
if previous_issuer:
if not str(previous_issuer) == str(cert.get_subject()): # The chain cannot be valid
print "FAIL (Usage 2): Certificates don't chain"
break
previous_issuer = cert.get_issuer()
if verifyCertMatch(record, cert):
matched = True
continue
if matched:
print 'SUCCESS (Usage 2): A certificate in the certificate chain (including the end-entity certificate) offered by the server matches the TLSA record'
if not args.quiet: print 'The matched certificate has Subject: %s' % cert.get_subject()
else:
print 'FAIL (Usage 2): No certificate in the certificate chain (including the end-entity certificate) offered by the server matches the TLSA record'
if pre_exit == 0: pre_exit = 2
elif record.usage == 3: # EE cert MUST match
if verifyCertMatch(record,chain[0]):
print 'SUCCESS (Usage 3): The certificate offered by the server matches the TLSA record'
if not args.quiet: print 'The matched certificate has Subject: %s' % chain[0].get_subject()
else:
print 'FAIL (Usage 3): The certificate offered by the server does not match the TLSA record'
if pre_exit == 0: pre_exit = 2
# Cleanup, just in case
connection.clear()
connection.close()
ctx.close()
# END for address in addresses
# END for record in records
sys.exit(pre_exit)
# END if args.verify
else: # we want to create
cert = None
if not args.certificate:
if args.protocol != 'tcp':
print >> sys.stderr, 'Only SSL over TCP is supported (sorry)'
sys.exit(1)
print 'No certificate specified on the commandline, attempting to retrieve it from the server %s' % (args.host)
connection_port = args.port
if args.port == '*':
sys.stdout.write('The port specified on the commandline is *, please specify the port of the TLS service on %s (443): ' % args.host)
input_ok = False
while not input_ok:
user_input = raw_input()
if user_input == '':
connection_port = 443
break
try:
if 1 <= int(user_input) <= 65535:
connection_port = user_input
input_ok = True
except:
sys.stdout.write('Port %s not numerical or within correct range (1 <= port <= 65535), try again (hit enter for default 443): ' % user_input)
# Get the address records for the host
try:
addresses = getA(args.host, secure=secure) + getAAAA(args.host, secure=secure)
except InsecureLookupException, e:
print >> sys.stderr, str(e)
sys.exit(1)
for address in addresses:
print 'Attempting to get certificate from %s' % str(address)
# We do the certificate handling here, as M2Crypto keeps segfaulting when try to do stuff with the cert if we don't
ctx = SSL.Context()
ctx.set_verify(SSL.verify_none, depth=9)
if isinstance(address, AAAARecord):
sock = socket.socket(socket.AF_INET6, socket.SOCK_STREAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
else:
sock = None
connection = StartTLSConnection(ctx, sock=sock)
# Try to use SNI for virtual hosts if available
try:
# We don't want the trailing dot here
connection.set_tlsext_host_name(args.host[:-1])
except AttributeError:
if not args.quiet: print >> sys.stderr, 'M2Crypto does not support SNI: services using virtual-hosting will show the wrong certificate!'
try:
connection.connect((str(address), int(connection_port)), args.starttls)
except SSL.Checker.WrongHost:
pass
except socket.error, e:
print 'Cannot connect to %s: %s' % (address, str(e))
continue
chain = connection.get_peer_cert_chain()
for chaincert in chain:
if int(args.usage) == 1 or int(args.usage) == 3:
# The first cert is the end-entity cert
print 'Got a certificate with Subject: %s' % chaincert.get_subject()
cert = chaincert
break
else:
if (int(args.usage) == 0 and chaincert.check_ca()) or int(args.usage) == 2:
sys.stdout.write('Got a certificate with the following Subject:\n\t%s\nUse this as certificate to match? [y/N] ' % chaincert.get_subject())
input_ok = False
while not input_ok:
user_input = raw_input()
if user_input in ['','n','N']:
input_ok=True
elif user_input in ['y', 'Y']:
input_ok = True
cert = chaincert
else:
sys.stdout.write('Please answer Y or N')
if cert:
break
if cert: # Print the requested records based on the retrieved certificates
if args.output == 'both':
print genTLSA(args.host, args.protocol, args.port, cert, 'generic', args.usage, args.selector, args.mtype)
print genTLSA(args.host, args.protocol, args.port, cert, 'rfc', args.usage, args.selector, args.mtype)
else:
print genTLSA(args.host, args.protocol, args.port, cert, args.output, args.usage, args.selector, args.mtype)
# Clear the cert from memory (to stop M2Crypto from segfaulting)
# And cleanup the connection and context
cert=None
connection.clear()
connection.close()
ctx.close()
else: # Pass the path to the certificate to the genTLSA function
if args.output == 'both':
print genTLSA(args.host, args.protocol, args.port, args.certificate, 'generic', args.usage, args.selector, args.mtype)
print genTLSA(args.host, args.protocol, args.port, args.certificate, 'rfc', args.usage, args.selector, args.mtype)
else:
print genTLSA(args.host, args.protocol, args.port, args.certificate, args.output, args.usage, args.selector, args.mtype)