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Lemur cryptography refactor and updates (#668)

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* Renaming the function so it sounds less root-specific

* Refactoring lemur_cryptography
* Adding to the certificate interface an easy way to request the subject and public_key of a certificate
* Turning the create authority functionality into a wrapper of creating a CSR in the certificate codebase and issueing that certificate in this plugin. (Dependent on https://github.com/Netflix/lemur/pull/666 changes first)
* Ensuring that intermediate certificates and signed certificates retain their chain cert data

* Handling extensions that are the responsibility of the CA
Implementing authority_key_identifier for lemur_cryptography signatures and including skeletons of handling the certificate_info_access and crl_distribution_points

* Fixing errors found with linter

* Updating plugin unit tests

* Changing this for Python3. Underlying cryptography library expects these to be bytes now.

* Updating tests to match new function names/interfaces

* Another naming update in the plugin tests

* Appears that create_csr won't like this input without an owner.

* Undoing last commit and putting it into the right place this time.

* create_csr should be good now with these options, and chain certs will be blank in tests

* This won't be blank in issue_certificate, like it will in creating an authority.

* Much cleaner

* unnecessary import
This commit is contained in:
Neil Schelly 2017-02-01 13:34:24 -05:00 committed by kevgliss
parent b7833d8e09
commit 117009c0a2
3 changed files with 109 additions and 60 deletions
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10
lemur/certificates/models.py
View File

@ -200,6 +200,16 @@ class Certificate(db.Model):
def validity_range(self):
return self.not_after - self.not_before
@property
def subject(self):
cert = lemur.common.utils.parse_certificate(self.body)
return cert.subject
@property
def public_key(self):
cert = lemur.common.utils.parse_certificate(self.body)
return cert.public_key()
@hybrid_property
def expired(self):
if self.not_after <= arrow.utcnow():

142
lemur/plugins/lemur_cryptography/plugin.py
View File

@ -17,78 +17,114 @@ from cryptography.hazmat.primitives import hashes, serialization
from lemur.plugins.bases import IssuerPlugin
from lemur.plugins import lemur_cryptography as cryptography_issuer
from lemur.common.utils import generate_private_key
from lemur.certificates.service import create_csr
def build_root_certificate(options):
private_key = generate_private_key(options.get('key_type'))
def build_certificate_authority(options):
options['certificate_authority'] = True
csr, private_key = create_csr(**options)
cert_pem, chain_cert_pem = issue_certificate(csr, options, private_key)
subject = issuer = x509.Name([
x509.NameAttribute(x509.OID_COUNTRY_NAME, options['country']),
x509.NameAttribute(x509.OID_STATE_OR_PROVINCE_NAME, options['state']),
x509.NameAttribute(x509.OID_LOCALITY_NAME, options['location']),
x509.NameAttribute(x509.OID_ORGANIZATION_NAME, options['organization']),
x509.NameAttribute(x509.OID_ORGANIZATIONAL_UNIT_NAME, options['organizational_unit']),
x509.NameAttribute(x509.OID_COMMON_NAME, options['common_name'])
])
builder = x509.CertificateBuilder(
subject_name=subject,
issuer_name=issuer,
public_key=private_key.public_key(),
not_valid_after=options['validity_end'],
not_valid_before=options['validity_start'],
serial_number=options['first_serial']
)
builder.add_extension(x509.SubjectAlternativeName([x509.DNSName(options['common_name'])]), critical=False)
cert = builder.sign(private_key, hashes.SHA256(), default_backend())
cert_pem = cert.public_bytes(
encoding=serialization.Encoding.PEM
).decode('utf-8')
private_key_pem = private_key.private_bytes(
encoding=serialization.Encoding.PEM,
format=serialization.PrivateFormat.TraditionalOpenSSL, # would like to use PKCS8 but AWS ELBs don't like it
encryption_algorithm=serialization.NoEncryption()
)
return cert_pem, private_key_pem
return cert_pem, private_key, chain_cert_pem
def issue_certificate(csr, options):
def issue_certificate(csr, options, private_key=None):
csr = x509.load_pem_x509_csr(csr.encode('utf-8'), default_backend())
if options.get("parent"):
# creating intermediate authorities will have options['parent'] to specify the issuer
# creating certificates will have options['authority'] to specify the issuer
# This works around that by making sure options['authority'] can be referenced for either
options['authority'] = options['parent']
if options.get("authority"):
# Issue certificate signed by an existing lemur_certificates authority
issuer_subject = options['authority'].authority_certificate.subject
issuer_private_key = options['authority'].authority_certificate.private_key
chain_cert_pem = options['authority'].authority_certificate.body
authority_key_identifier_public = options['authority'].authority_certificate.public_key
authority_key_identifier_subject = x509.SubjectKeyIdentifier.from_public_key(authority_key_identifier_public)
authority_key_identifier_issuer = issuer_subject
authority_key_identifier_serial = int(options['authority'].authority_certificate.serial)
# TODO figure out a better way to increment serial
# New authorities have a value at options['serial_number'] that is being ignored here.
serial = int(uuid.uuid4())
else:
# Issue certificate that is self-signed (new lemur_certificates root authority)
issuer_subject = csr.subject
issuer_private_key = private_key
chain_cert_pem = ""
authority_key_identifier_public = csr.public_key()
authority_key_identifier_subject = None
authority_key_identifier_issuer = csr.subject
authority_key_identifier_serial = options['serial_number']
# TODO figure out a better way to increment serial
serial = int(uuid.uuid4())
builder = x509.CertificateBuilder(
issuer_name=x509.Name([
x509.NameAttribute(
x509.OID_ORGANIZATION_NAME,
options['authority'].authority_certificate.issuer
)]
),
issuer_name=issuer_subject,
subject_name=csr.subject,
public_key=csr.public_key(),
not_valid_before=options['validity_start'],
not_valid_after=options['validity_end'],
extensions=csr.extensions)
serial_number=serial,
extensions=csr.extensions._extensions)
# TODO figure out a better way to increment serial
builder = builder.serial_number(int(uuid.uuid4()))
for k, v in options.get('extensions', {}).items():
if k == 'authority_key_identifier':
# One or both of these options may be present inside the aki extension
(authority_key_identifier, authority_identifier) = (False, False)
for k2, v2 in v.items():
if k2 == 'use_key_identifier' and v2:
authority_key_identifier = True
if k2 == 'use_authority_cert' and v2:
authority_identifier = True
if authority_key_identifier:
if authority_key_identifier_subject:
# FIXME in python-cryptography.
# from_issuer_subject_key_identifier(cls, ski) is looking for ski.value.digest
# but the digest of the ski is at just ski.digest. Until that library is fixed,
# this function won't work. The second line has the same result.
# aki = x509.AuthorityKeyIdentifier.from_issuer_subject_key_identifier(authority_key_identifier_subject)
aki = x509.AuthorityKeyIdentifier(authority_key_identifier_subject.digest, None, None)
else:
aki = x509.AuthorityKeyIdentifier.from_issuer_public_key(authority_key_identifier_public)
if authority_key_identifier and authority_identifier:
aki = x509.AuthorityKeyIdentifier(aki.key_identifier, [x509.DirectoryName(authority_key_identifier_issuer)], authority_key_identifier_serial)
elif authority_identifier:
aki = x509.AuthorityKeyIdentifier(None, [x509.DirectoryName(authority_key_identifier_issuer)], authority_key_identifier_serial)
builder = builder.add_extension(aki, critical=False)
if k == 'certificate_info_access':
# FIXME: Implement the AuthorityInformationAccess extension
# descriptions = [
# x509.AccessDescription(x509.oid.AuthorityInformationAccessOID.OCSP, x509.UniformResourceIdentifier(u"http://FIXME")),
# x509.AccessDescription(x509.oid.AuthorityInformationAccessOID.CA_ISSUERS, x509.UniformResourceIdentifier(u"http://FIXME"))
# ]
# for k2, v2 in v.items():
# if k2 == 'include_aia' and v2 == True:
# builder = builder.add_extension(
# x509.AuthorityInformationAccess(descriptions),
# critical=False
# )
pass
if k == 'crl_distribution_points':
# FIXME: Implement the CRLDistributionPoints extension
# FIXME: Not implemented in lemur/schemas.py yet https://github.com/Netflix/lemur/issues/662
pass
private_key = serialization.load_pem_private_key(
bytes(str(options['authority'].authority_certificate.private_key).encode('utf-8')),
bytes(str(issuer_private_key).encode('utf-8')),
password=None,
backend=default_backend()
)
cert = builder.sign(private_key, hashes.SHA256(), default_backend())
return cert.public_bytes(
cert_pem = cert.public_bytes(
encoding=serialization.Encoding.PEM
).decode('utf-8')
return cert_pem, chain_cert_pem
class CryptographyIssuerPlugin(IssuerPlugin):
title = 'Cryptography'
@ -108,8 +144,8 @@ class CryptographyIssuerPlugin(IssuerPlugin):
:return: :raise Exception:
"""
current_app.logger.debug("Issuing new cryptography certificate with options: {0}".format(options))
cert = issue_certificate(csr, options)
return cert, ""
cert_pem, chain_cert_pem = issue_certificate(csr, options)
return cert_pem, chain_cert_pem
@staticmethod
def create_authority(options):
@ -121,9 +157,9 @@ class CryptographyIssuerPlugin(IssuerPlugin):
:return:
"""
current_app.logger.debug("Issuing new cryptography authority with options: {0}".format(options))
cert, private_key = build_root_certificate(options)
cert_pem, private_key, chain_cert_pem = build_certificate_authority(options)
roles = [
{'username': '', 'password': '', 'name': options['name'] + '_admin'},
{'username': '', 'password': '', 'name': options['name'] + '_operator'}
]
return cert, private_key, "", roles
return cert_pem, private_key, chain_cert_pem, roles

17
lemur/plugins/lemur_cryptography/tests/test_cryptography.py
View File

@ -1,8 +1,8 @@
import arrow
def test_build_root_certificate():
from lemur.plugins.lemur_cryptography.plugin import build_root_certificate
def test_build_certificate_authority():
from lemur.plugins.lemur_cryptography.plugin import build_certificate_authority
options = {
'key_type': 'RSA2048',
@ -14,13 +14,15 @@ def test_build_root_certificate():
'common_name': 'Example ROOT',
'validity_start': arrow.get('2016-12-01').datetime,
'validity_end': arrow.get('2016-12-02').datetime,
'first_serial': 1
'first_serial': 1,
'serial_number': 1,
'owner': 'owner@example.com'
}
cert_pem, private_key_pem = build_root_certificate(options)
cert_pem, private_key_pem, chain_cert_pem = build_certificate_authority(options)
assert cert_pem
assert private_key_pem
assert chain_cert_pem == ''
def test_issue_certificate(authority):
@ -32,5 +34,6 @@ def test_issue_certificate(authority):
'validity_start': arrow.get('2016-12-01').datetime,
'validity_end': arrow.get('2016-12-02').datetime
}
cert = issue_certificate(CSR_STR, options)
assert cert
cert_pem, chain_cert_pem = issue_certificate(CSR_STR, options)
assert cert_pem
assert chain_cert_pem