nova/nova/crypto.py

467 lines
16 KiB
Python

# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
"""Wrappers around standard crypto data elements.
Includes root and intermediate CAs, SSH key_pairs and x509 certificates.
"""
from __future__ import absolute_import
import base64
import binascii
import os
import re
import string
import StringIO
import struct
from oslo_concurrency import processutils
from oslo_config import cfg
from oslo_log import log as logging
from oslo_utils import excutils
from oslo_utils import timeutils
import paramiko
from pyasn1.codec.der import encoder as der_encoder
from pyasn1.type import univ
from nova import context
from nova import db
from nova import exception
from nova.i18n import _, _LE
from nova.openstack.common import fileutils
from nova import paths
from nova import utils
LOG = logging.getLogger(__name__)
crypto_opts = [
cfg.StrOpt('ca_file',
default='cacert.pem',
help=_('Filename of root CA')),
cfg.StrOpt('key_file',
default=os.path.join('private', 'cakey.pem'),
help=_('Filename of private key')),
cfg.StrOpt('crl_file',
default='crl.pem',
help=_('Filename of root Certificate Revocation List')),
cfg.StrOpt('keys_path',
default=paths.state_path_def('keys'),
help=_('Where we keep our keys')),
cfg.StrOpt('ca_path',
default=paths.state_path_def('CA'),
help=_('Where we keep our root CA')),
cfg.BoolOpt('use_project_ca',
default=False,
help=_('Should we use a CA for each project?')),
cfg.StrOpt('user_cert_subject',
default='/C=US/ST=California/O=OpenStack/'
'OU=NovaDev/CN=%.16s-%.16s-%s',
help=_('Subject for certificate for users, %s for '
'project, user, timestamp')),
cfg.StrOpt('project_cert_subject',
default='/C=US/ST=California/O=OpenStack/'
'OU=NovaDev/CN=project-ca-%.16s-%s',
help=_('Subject for certificate for projects, %s for '
'project, timestamp')),
]
CONF = cfg.CONF
CONF.register_opts(crypto_opts)
def ca_folder(project_id=None):
if CONF.use_project_ca and project_id:
return os.path.join(CONF.ca_path, 'projects', project_id)
return CONF.ca_path
def ca_path(project_id=None):
return os.path.join(ca_folder(project_id), CONF.ca_file)
def key_path(project_id=None):
return os.path.join(ca_folder(project_id), CONF.key_file)
def crl_path(project_id=None):
return os.path.join(ca_folder(project_id), CONF.crl_file)
def fetch_ca(project_id=None):
if not CONF.use_project_ca:
project_id = None
ca_file_path = ca_path(project_id)
if not os.path.exists(ca_file_path):
raise exception.CryptoCAFileNotFound(project=project_id)
with open(ca_file_path, 'r') as cafile:
return cafile.read()
def ensure_ca_filesystem():
"""Ensure the CA filesystem exists."""
ca_dir = ca_folder()
if not os.path.exists(ca_path()):
genrootca_sh_path = os.path.abspath(
os.path.join(os.path.dirname(__file__), 'CA', 'genrootca.sh'))
start = os.getcwd()
fileutils.ensure_tree(ca_dir)
os.chdir(ca_dir)
try:
utils.execute("sh", genrootca_sh_path)
finally:
os.chdir(start)
def generate_fingerprint(public_key):
try:
parts = public_key.split(' ')
ssh_alg = parts[0]
pub_data = parts[1].decode('base64')
if ssh_alg == 'ssh-rsa':
pkey = paramiko.RSAKey(data=pub_data)
elif ssh_alg == 'ssh-dss':
pkey = paramiko.DSSKey(data=pub_data)
elif ssh_alg == 'ecdsa-sha2-nistp256':
pkey = paramiko.ECDSAKey(data=pub_data, validate_point=False)
else:
raise exception.InvalidKeypair(
reason=_('Unknown ssh key type %s') % ssh_alg)
raw_fp = binascii.hexlify(pkey.get_fingerprint())
return ':'.join(a + b for a, b in zip(raw_fp[::2], raw_fp[1::2]))
except (IndexError, UnicodeDecodeError, binascii.Error,
paramiko.ssh_exception.SSHException):
raise exception.InvalidKeypair(
reason=_('failed to generate fingerprint'))
def generate_x509_fingerprint(pem_key):
try:
(out, _err) = utils.execute('openssl', 'x509', '-inform', 'PEM',
'-fingerprint', '-noout',
process_input=pem_key)
fingerprint = string.strip(out.rpartition('=')[2])
return fingerprint.lower()
except processutils.ProcessExecutionError as ex:
raise exception.InvalidKeypair(
reason=_('failed to generate X509 fingerprint. '
'Error message: %s') % ex)
def generate_key_pair(bits=2048):
key = paramiko.RSAKey.generate(bits)
keyout = StringIO.StringIO()
key.write_private_key(keyout)
private_key = keyout.getvalue()
public_key = '%s %s Generated-by-Nova' % (key.get_name(), key.get_base64())
fingerprint = generate_fingerprint(public_key)
return (private_key, public_key, fingerprint)
def fetch_crl(project_id):
"""Get crl file for project."""
if not CONF.use_project_ca:
project_id = None
crl_file_path = crl_path(project_id)
if not os.path.exists(crl_file_path):
raise exception.CryptoCRLFileNotFound(project=project_id)
with open(crl_file_path, 'r') as crlfile:
return crlfile.read()
def decrypt_text(project_id, text):
private_key = key_path(project_id)
if not os.path.exists(private_key):
raise exception.ProjectNotFound(project_id=project_id)
try:
dec, _err = utils.execute('openssl',
'rsautl',
'-decrypt',
'-inkey', '%s' % private_key,
process_input=text)
return dec
except processutils.ProcessExecutionError as exc:
raise exception.DecryptionFailure(reason=exc.stderr)
_RSA_OID = univ.ObjectIdentifier('1.2.840.113549.1.1.1')
def _to_sequence(*vals):
seq = univ.Sequence()
for i in range(len(vals)):
seq.setComponentByPosition(i, vals[i])
return seq
def convert_from_sshrsa_to_pkcs8(pubkey):
"""Convert a ssh public key to openssl format
Equivalent to the ssh-keygen's -m option
"""
# get the second field from the public key file.
try:
keydata = base64.b64decode(pubkey.split(None)[1])
except IndexError:
msg = _("Unable to find the key")
raise exception.EncryptionFailure(reason=msg)
# decode the parts of the key
parts = []
while keydata:
dlen = struct.unpack('>I', keydata[:4])[0]
data = keydata[4:dlen + 4]
keydata = keydata[4 + dlen:]
parts.append(data)
# Use asn to build the openssl key structure
#
# SEQUENCE(2 elem)
# +- SEQUENCE(2 elem)
# | +- OBJECT IDENTIFIER (1.2.840.113549.1.1.1)
# | +- NULL
# +- BIT STRING(1 elem)
# +- SEQUENCE(2 elem)
# +- INTEGER(2048 bit)
# +- INTEGER 65537
# Build the sequence for the bit string
n_val = int(
''.join(['%02X' % struct.unpack('B', x)[0] for x in parts[2]]), 16)
e_val = int(
''.join(['%02X' % struct.unpack('B', x)[0] for x in parts[1]]), 16)
pkinfo = _to_sequence(univ.Integer(n_val), univ.Integer(e_val))
# Convert the sequence into a bit string
pklong = long(der_encoder.encode(pkinfo).encode('hex'), 16)
pkbitstring = univ.BitString("'00%s'B" % bin(pklong)[2:])
# Build the key data structure
oid = _to_sequence(_RSA_OID, univ.Null())
pkcs1_seq = _to_sequence(oid, pkbitstring)
pkcs8 = base64.encodestring(der_encoder.encode(pkcs1_seq))
# Remove the embedded new line and format the key, each line
# should be 64 characters long
return ('-----BEGIN PUBLIC KEY-----\n%s\n-----END PUBLIC KEY-----\n' %
re.sub("(.{64})", "\\1\n", pkcs8.replace('\n', ''), re.DOTALL))
def ssh_encrypt_text(ssh_public_key, text):
"""Encrypt text with an ssh public key.
"""
with utils.tempdir() as tmpdir:
sslkey = os.path.abspath(os.path.join(tmpdir, 'ssl.key'))
try:
out = convert_from_sshrsa_to_pkcs8(ssh_public_key)
with open(sslkey, 'w') as f:
f.write(out)
enc, _err = utils.execute('openssl',
'rsautl',
'-encrypt',
'-pubin',
'-inkey', sslkey,
'-keyform', 'PEM',
process_input=text)
return enc
except processutils.ProcessExecutionError as exc:
raise exception.EncryptionFailure(reason=exc.stderr)
def revoke_cert(project_id, file_name):
"""Revoke a cert by file name."""
start = os.getcwd()
try:
os.chdir(ca_folder(project_id))
except OSError:
raise exception.ProjectNotFound(project_id=project_id)
try:
# NOTE(vish): potential race condition here
utils.execute('openssl', 'ca', '-config', './openssl.cnf', '-revoke',
file_name)
utils.execute('openssl', 'ca', '-gencrl', '-config', './openssl.cnf',
'-out', CONF.crl_file)
except processutils.ProcessExecutionError:
raise exception.RevokeCertFailure(project_id=project_id)
finally:
os.chdir(start)
def revoke_certs_by_user(user_id):
"""Revoke all user certs."""
admin = context.get_admin_context()
for cert in db.certificate_get_all_by_user(admin, user_id):
revoke_cert(cert['project_id'], cert['file_name'])
def revoke_certs_by_project(project_id):
"""Revoke all project certs."""
# NOTE(vish): This is somewhat useless because we can just shut down
# the vpn.
admin = context.get_admin_context()
for cert in db.certificate_get_all_by_project(admin, project_id):
revoke_cert(cert['project_id'], cert['file_name'])
def revoke_certs_by_user_and_project(user_id, project_id):
"""Revoke certs for user in project."""
admin = context.get_admin_context()
for cert in db.certificate_get_all_by_user_and_project(admin,
user_id, project_id):
revoke_cert(cert['project_id'], cert['file_name'])
def _project_cert_subject(project_id):
"""Helper to generate user cert subject."""
return CONF.project_cert_subject % (project_id, timeutils.isotime())
def _user_cert_subject(user_id, project_id):
"""Helper to generate user cert subject."""
return CONF.user_cert_subject % (project_id, user_id, timeutils.isotime())
def generate_x509_cert(user_id, project_id, bits=2048):
"""Generate and sign a cert for user in project."""
subject = _user_cert_subject(user_id, project_id)
with utils.tempdir() as tmpdir:
keyfile = os.path.abspath(os.path.join(tmpdir, 'temp.key'))
csrfile = os.path.abspath(os.path.join(tmpdir, 'temp.csr'))
utils.execute('openssl', 'genrsa', '-out', keyfile, str(bits))
utils.execute('openssl', 'req', '-new', '-key', keyfile, '-out',
csrfile, '-batch', '-subj', subject)
with open(keyfile) as f:
private_key = f.read()
with open(csrfile) as f:
csr = f.read()
(serial, signed_csr) = sign_csr(csr, project_id)
fname = os.path.join(ca_folder(project_id), 'newcerts/%s.pem' % serial)
cert = {'user_id': user_id,
'project_id': project_id,
'file_name': fname}
db.certificate_create(context.get_admin_context(), cert)
return (private_key, signed_csr)
def generate_winrm_x509_cert(user_id, project_id, bits=2048):
"""Generate a cert for passwordless auth for user in project."""
subject = '/CN=%s-%s' % (project_id, user_id)
upn = '%s@localhost' % user_id
with utils.tempdir() as tmpdir:
keyfile = os.path.abspath(os.path.join(tmpdir, 'temp.key'))
conffile = os.path.abspath(os.path.join(tmpdir, 'temp.conf'))
_create_x509_openssl_config(conffile, upn)
(certificate, _err) = utils.execute(
'openssl', 'req', '-x509', '-nodes', '-days', '3650',
'-config', conffile, '-newkey', 'rsa:%s' % bits,
'-outform', 'PEM', '-keyout', keyfile, '-subj', subject,
'-extensions', 'v3_req_client')
(out, _err) = utils.execute('openssl', 'pkcs12', '-export',
'-inkey', keyfile, '-password', 'pass:',
process_input=certificate)
private_key = out.encode('base64')
fingerprint = generate_x509_fingerprint(certificate)
return (private_key, certificate, fingerprint)
def _create_x509_openssl_config(conffile, upn):
content = ("distinguished_name = req_distinguished_name\n"
"[req_distinguished_name]\n"
"[v3_req_client]\n"
"extendedKeyUsage = clientAuth\n"
"subjectAltName = otherName:""1.3.6.1.4.1.311.20.2.3;UTF8:%s\n")
with open(conffile, 'w') as file:
file.write(content % upn)
def _ensure_project_folder(project_id):
if not os.path.exists(ca_path(project_id)):
geninter_sh_path = os.path.abspath(
os.path.join(os.path.dirname(__file__), 'CA', 'geninter.sh'))
start = os.getcwd()
os.chdir(ca_folder())
utils.execute('sh', geninter_sh_path, project_id,
_project_cert_subject(project_id))
os.chdir(start)
def generate_vpn_files(project_id):
project_folder = ca_folder(project_id)
key_fn = os.path.join(project_folder, 'server.key')
crt_fn = os.path.join(project_folder, 'server.crt')
if os.path.exists(crt_fn):
return
# NOTE(vish): The 2048 is to maintain compatibility with the old script.
# We are using "project-vpn" as the user_id for the cert
# even though that user may not really exist. Ultimately
# this will be changed to be launched by a real user. At
# that point we will can delete this helper method.
key, csr = generate_x509_cert('project-vpn', project_id, 2048)
with open(key_fn, 'w') as keyfile:
keyfile.write(key)
with open(crt_fn, 'w') as crtfile:
crtfile.write(csr)
def sign_csr(csr_text, project_id=None):
if not CONF.use_project_ca:
project_id = None
if not project_id:
return _sign_csr(csr_text, ca_folder())
_ensure_project_folder(project_id)
return _sign_csr(csr_text, ca_folder(project_id))
def _sign_csr(csr_text, ca_folder):
with utils.tempdir() as tmpdir:
inbound = os.path.join(tmpdir, 'inbound.csr')
outbound = os.path.join(tmpdir, 'outbound.csr')
try:
with open(inbound, 'w') as csrfile:
csrfile.write(csr_text)
except IOError:
with excutils.save_and_reraise_exception():
LOG.exception(_LE('Failed to write inbound.csr'))
LOG.debug('Flags path: %s', ca_folder)
start = os.getcwd()
# Change working dir to CA
fileutils.ensure_tree(ca_folder)
os.chdir(ca_folder)
utils.execute('openssl', 'ca', '-batch', '-out', outbound, '-config',
'./openssl.cnf', '-infiles', inbound)
out, _err = utils.execute('openssl', 'x509', '-in', outbound,
'-serial', '-noout')
serial = string.strip(out.rpartition('=')[2])
os.chdir(start)
with open(outbound, 'r') as crtfile:
return (serial, crtfile.read())