authentic/src/authentic2/saml/x509utils.py

186 lines
6.7 KiB
Python

# authentic2 - versatile identity manager
# Copyright (C) 2010-2019 Entr'ouvert
#
# This program is free software: you can redistribute it and/or modify it
# under the terms of the GNU Affero General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
import base64
import binascii
import tempfile
import os
import subprocess
import stat
import six
_openssl = 'openssl'
def decapsulate_pem_file(file_or_string):
'''Remove PEM header lines'''
if not isinstance(file_or_string, six.string_types):
content = file_or_string.read()
else:
content = file_or_string
i = content.find('--BEGIN')
j = content.find('\n', i)
k = content.find('--END', j)
l = content.rfind('\n', 0, k) # noqa: E741
return content[j + 1:l]
def _call_openssl(args):
'''Use subprocees to spawn an openssl process
Return a tuple made of the return code and the stdout output
'''
try:
process = subprocess.Popen(args=[_openssl] + args,
stdout=subprocess.PIPE,
stderr=subprocess.STDOUT,
universal_newlines=True)
output = process.communicate()[0]
return process.returncode, output
except OSError:
return 1, None
def _protect_file(fd, filepath):
'''Make a file targeted by a file descriptor readable only by the current user
It's needed to be sure nobody can read the private key file we manage.
'''
os.fchmod(fd, stat.S_IRUSR | stat.S_IWUSR)
def check_key_pair_consistency(publickey=None, privatekey=None):
'''Check if two PEM key pair whether they are publickey or certificate, are
well formed and related.
'''
if publickey and privatekey:
try:
privatekey_file_fd, privatekey_fn = tempfile.mkstemp()
publickey_file_fd, publickey_fn = tempfile.mkstemp()
_protect_file(privatekey_file_fd, privatekey_fn)
_protect_file(publickey_file_fd, publickey_fn)
os.fdopen(privatekey_file_fd, 'w').write(privatekey)
os.fdopen(publickey_file_fd, 'w').write(publickey)
if 'BEGIN CERTIFICATE' in publickey:
rc1, modulus1 = _call_openssl(['x509', '-in', publickey_fn, '-noout', '-modulus'])
else:
rc1, modulus1 = _call_openssl(['rsa', '-pubin', '-in', publickey_fn, '-noout', '-modulus'])
if rc1 != 0:
rc1, modulus1 = _call_openssl(['dsa', '-pubin', '-in', publickey_fn, '-noout', '-modulus'])
if rc1 != 0:
return False
rc2, modulus2 = _call_openssl(['rsa', '-in', privatekey_fn, '-noout', '-modulus'])
if rc2 != 0:
rc2, modulus2 = _call_openssl(['dsa', '-in', privatekey_fn, '-noout', '-modulus'])
if rc1 == 0 and rc2 == 0 and modulus1 == modulus2:
return True
else:
return False
finally:
os.unlink(privatekey_fn)
os.unlink(publickey_fn)
return None
def generate_rsa_keypair(numbits=1024):
'''Generate simple RSA public and private key files
'''
try:
privatekey_file_fd, privatekey_fn = tempfile.mkstemp()
publickey_file_fd, publickey_fn = tempfile.mkstemp()
_protect_file(privatekey_file_fd, privatekey_fn)
_protect_file(publickey_file_fd, publickey_fn)
rc1, _ = _call_openssl(['genrsa', '-out', privatekey_fn, '-passout', 'pass:', str(numbits)])
rc2, _ = _call_openssl(['rsa', '-in', privatekey_fn, '-pubout', '-out', publickey_fn])
if rc1 != 0 or rc2 != 0:
raise Exception('Failed to generate a key')
return (os.fdopen(publickey_file_fd).read(), os.fdopen(privatekey_file_fd).read())
finally:
os.unlink(privatekey_fn)
os.unlink(publickey_fn)
def get_rsa_public_key_modulus(publickey):
try:
publickey_file_fd, publickey_fn = tempfile.mkstemp()
os.fdopen(publickey_file_fd, 'w').write(publickey)
if 'BEGIN PUBLIC' in publickey:
rc, modulus = _call_openssl(['rsa', '-pubin', '-in', publickey_fn, '-noout', '-modulus'])
elif 'BEGIN RSA PRIVATE KEY' in publickey:
rc, modulus = _call_openssl(['rsa', '-in', publickey_fn, '-noout', '-modulus'])
elif 'BEGIN CERTIFICATE' in publickey:
rc, modulus = _call_openssl(['x509', '-in', publickey_fn, '-noout', '-modulus'])
else:
return None
i = modulus.find('=')
if rc == 0 and i:
return int(modulus[i + 1:].strip(), 16)
finally:
os.unlink(publickey_fn)
return None
def get_rsa_public_key_exponent(publickey):
try:
publickey_file_fd, publickey_fn = tempfile.mkstemp()
os.fdopen(publickey_file_fd, 'w').write(publickey)
_exponent = 'Exponent: '
if 'BEGIN PUBLIC' in publickey:
rc, modulus = _call_openssl(['rsa', '-pubin', '-in', publickey_fn, '-noout', '-text'])
elif 'BEGIN RSA PRIVATE' in publickey:
rc, modulus = _call_openssl(['rsa', '-in', publickey_fn, '-noout', '-text'])
_exponent = 'publicExponent: '
elif 'BEGIN CERTIFICATE' in publickey:
rc, modulus = _call_openssl(['x509', '-in', publickey_fn, '-noout', '-text'])
else:
return None
i = modulus.find(_exponent)
j = modulus.find('(', i)
if rc == 0 and i and j:
return int(modulus[i + len(_exponent):j].strip())
finally:
os.unlink(publickey_fn)
return None
def can_generate_rsa_key_pair():
syspath = os.environ.get('PATH')
if syspath:
for base in syspath.split(':'):
if os.path.exists(os.path.join(base, 'openssl')):
return True
else:
return False
def get_xmldsig_rsa_key_value(publickey):
def int_to_bin(i):
h = hex(i)[2:].strip('L')
if len(h) % 2 == 1:
h = '0' + h
return binascii.unhexlify(h)
mod = get_rsa_public_key_modulus(publickey)
exp = get_rsa_public_key_exponent(publickey)
return (
'<RSAKeyValue xmlns="http://www.w3.org/2000/09/xmldsig#">\n\t'
'<Modulus>%s</Modulus>\n\t'
'<Exponent>%s</Exponent>\n</RSAKeyValue>' % (
base64.b64encode(int_to_bin(mod)), base64.b64encode(int_to_bin(exp))))