vmmgr/usr/lib/python3.6/vmmgr/crypto.py

83 lines
3.9 KiB
Python

# -*- coding: utf-8 -*-
import bcrypt
import datetime
import hashlib
import os
from cryptography import x509
from cryptography.exceptions import InvalidSignature
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives import hashes, serialization
from cryptography.hazmat.primitives.asymmetric import ec
from cryptography.x509.oid import NameOID, ExtendedKeyUsageOID
from .paths import ACME_CRON, CERT_PUB_FILE, CERT_KEY_FILE, PKG_SIG_FILE
def verify_signature(file, signature):
# Verifies ECDSA HMAC SHA512 signature of a file
with open(PKG_SIG_FILE, 'rb') as f:
pub_key = serialization.load_pem_public_key(f.read(), default_backend())
pub_key.verify(signature, file, ec.ECDSA(hashes.SHA512()))
def verify_hash(file, expected_hash):
# Verifies SHA512 hash of a file against expected hash
sha512 = hashlib.sha512()
with open(file, 'rb') as f:
while True:
data = f.read(65536)
if not data:
break
sha512.update(data)
if sha512.hexdigest() != expected_hash:
raise InvalidSignature(file)
def create_selfsigned_cert(domain):
# Create selfsigned certificate with wildcard alternative subject name
private_key = ec.generate_private_key(ec.SECP384R1(), default_backend())
public_key = private_key.public_key()
subject = x509.Name([x509.NameAttribute(NameOID.COMMON_NAME, domain)])
now = datetime.datetime.utcnow()
cert = x509.CertificateBuilder() \
.subject_name(subject) \
.issuer_name(subject) \
.public_key(public_key) \
.serial_number(x509.random_serial_number()) \
.not_valid_before(now) \
.not_valid_after(now + datetime.timedelta(days=7305)) \
.add_extension(x509.SubjectAlternativeName((x509.DNSName(domain), x509.DNSName('*.{}'.format(domain)))), critical=False) \
.add_extension(x509.SubjectKeyIdentifier.from_public_key(public_key), critical=False) \
.add_extension(x509.AuthorityKeyIdentifier.from_issuer_public_key(public_key), critical=False) \
.add_extension(x509.BasicConstraints(ca=False, path_length=None), critical=True) \
.add_extension(x509.KeyUsage(digital_signature=True, content_commitment=False, key_encipherment=False, data_encipherment=False, key_agreement=False, key_cert_sign=False, crl_sign=False, encipher_only=False, decipher_only=False), critical=True) \
.add_extension(x509.ExtendedKeyUsage((ExtendedKeyUsageOID.SERVER_AUTH, ExtendedKeyUsageOID.CLIENT_AUTH)), critical=False) \
.sign(private_key, hashes.SHA256(), default_backend())
with open(CERT_PUB_FILE, 'wb') as f:
f.write(cert.public_bytes(serialization.Encoding.PEM))
with open(CERT_KEY_FILE, 'wb') as f:
f.write(private_key.private_bytes(serialization.Encoding.PEM, serialization.PrivateFormat.PKCS8, serialization.NoEncryption()))
os.chmod(CERT_KEY_FILE, 0o640)
def get_cert_info():
# Gather certificate data important for setup-host
with open(CERT_PUB_FILE, 'rb') as f:
cert = x509.load_pem_x509_certificate(f.read(), default_backend())
data = {'subject': cert.subject.get_attributes_for_oid(NameOID.COMMON_NAME)[0].value,
'issuer': cert.issuer.get_attributes_for_oid(NameOID.COMMON_NAME)[0].value,
'expires': '{} UTC'.format(cert.not_valid_after),
'method': 'manual'}
if os.access(ACME_CRON, os.X_OK):
data['method'] = 'automatic'
# Naive method of inferring if the cert is selfsigned
# Good enough as reputable CAs will never have the same subject and issuer CN
# and the 'method' field is used just to populate a GUI element and not for any real cryptography
elif data['subject'] == data['issuer']:
data['method'] = 'selfsigned'
return data
def adminpwd_hash(password):
return bcrypt.hashpw(password.encode(), bcrypt.gensalt()).decode()
def adminpwd_verify(password, pwhash):
return bcrypt.checkpw(password.encode(), pwhash.encode())