cryptography_extension_test.py

from cryptography import x509
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives import  hashes
from cryptography.hazmat.primitives.asymmetric import rsa
from cryptography.x509.oid import NameOID
import datetime

one_day = datetime.timedelta(1, 0, 0)
private_key = rsa.generate_private_key(
    public_exponent=65537,
    key_size=2048,
    backend=default_backend()
)
public_key = private_key.public_key()

builder = x509.CertificateBuilder()

builder = builder.subject_name(x509.Name([
    x509.NameAttribute(NameOID.COMMON_NAME, u'istanbulnet.io'),
]))
builder = builder.issuer_name(x509.Name([
    x509.NameAttribute(NameOID.COMMON_NAME, u'istanbulnet.io'),
]))
builder = builder.not_valid_before(datetime.datetime.today() - one_day)
builder = builder.not_valid_after(datetime.datetime.today() + (one_day * 30))

builder = builder.serial_number(x509.random_serial_number())

builder = builder.public_key(public_key)

builder = builder.add_extension(
    x509.SubjectAlternativeName(
        [x509.DNSName(u'istanbulnet.io')]
    ),
    critical=False
)
builder = builder.add_extension(
    x509.BasicConstraints(ca=False, path_length=None), critical=True,
)
builder = builder.add_extension(
    x509.AuthorityInformationAccess([
        x509.AccessDescription(x509.AuthorityInformationAccessOID.CA_ISSUERS,
                               x509.DirectoryName('ldap:///blah'))
    ])
)
certificate = builder.sign(
    private_key=private_key, algorithm=hashes.SHA256(),
    backend=default_backend()
)