cnert

Cnert - TLS Certificates for testing

Cnert is simple Python API for creating TLS Certificates and stuff for testing purposes (on top of cryptography).

cnert.CA makes it easy to create CAs, intermediate CAs. These CA objects can then issue directly certificates.

Cnert can make CSRs. CA objects also use these to issue certificates.

Subject and Issuer Name Attributes, Subject Alternative Names, not_before_date and not_after_data can all be set.

Cnert has different methods to introspect these.

Cnert is made specially made for testing application that do something with TLS certificate and there for can make tailor made certificates for testing those apps.

If you don't need that and you just need any "old" certificate, you probably better of with trustme, trust me, or better: trust them.

Usage

Create a root CA

>>> import cnert
>>> ca = cnert.CA()

>>> ca.is_root_ca
True

>>> ca.is_intermediate_ca
False

>>> ca.parent is None
True

Issue an intermediate CA

>>> intermediate = ca.issue_intermediate()
>>> intermediate.is_intermediate_ca
True

>>> intermediate.is_root_ca
False

>>> intermediate.parent is ca
True

Inspect the CA's certificate

>>> ca.cert
<cnert.Cert at 0x112a14c50>

>>> ca.cert.subject_attrs
NameAttrs(ORGANIZATION_NAME="Root CA")

>>> ca.cert.subject_attrs.dict_
{'ORGANIZATION_NAME': 'Root CA'}

>>> ca.cert.subject_attrs.ORGANIZATION_NAME
'Root CA'

>>> ca.cert.ca.cert.issuer_attrs
NameAttrs(ORGANIZATION_NAME="Root CA")

>>> ca.cert.not_valid_before
datetime.datetime(2023, 3, 24, 21, 27, 50, 579389

>>> ca.cert.not_valid_after
datetime.datetime(2023, 6, 23, 20, 20, 47, 999034)

>>> ca.cert.not_valid_after
datetime.datetime(2023, 6, 23, 20, 20, 47, 999034)

>>> ca.cert.serial_number
710111479237500376112637726504312543434663217892

>>> ca.cert.path_length
9

>>> ca.cert.public_key.key_size
2048

>>> ca.cert.pem
b'-----BEGIN CERTIFICATE-----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\nDdGK6Wz0AXMWWbbX8LToDrFA9q7YOxGNOVPhbHZ++bDJvLNmjrtruy3UTQ==\n-----END CERTIFICATE-----\n'

Inspect the Intermediate CA

>>> intermediate.cert.subject_attrs
NameAttrs(ORGANIZATION_NAME="CA Intermediate 1")

>>> intermediate.cert.ca.cert.issuer_attrs
NameAttrs(ORGANIZATION_NAME="Root CA")

>>> intermediate.cert.path_length
8

Issue a cert from a CA (without CSR)

>>> cert = ca.issue_cert()

>>> cert.subject_attrs
NameAttrs(COMMON_NAME="example.com")

>>> cert.subject_attrs.dict_
{'COMMON_NAME': 'example.com'}

>>> cert.subject_attrs.COMMON_NAME
'example.com'

>>> cert.public_key
<cryptography.hazmat.backends.openssl.rsa._RSAPublicKey object at 0x10361c150>

>>> cert.pem
b'-----BEGIN CERTIFICATE-----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\nBE1OaNZaipKILZPbgDa5u67pRdU/OhuMFDsBh1GlPopcax+rCQ==\n-----END CERTIFICATE-----\n'

>>> cert.SHA1
'21B99CE5588417932ACB65C54398115C75240B04'

Issue a cert from a CA with alt names

>>> cert = ca.issue_cert("www.example.com", "host1.example.com", "example.com")

>>> cert.subject_attrs
NameAttrs(COMMON_NAME="www.example.com")

>>> cert.sans
('www.example.com', 'host1.example.com', 'example.com')

>>> cert.certificate.extensions[4]
<Extension(oid=<ObjectIdentifier(oid=2.5.29.17, name=subjectAltName)>, critical=True, value=<SubjectAlte rnativeName(<GeneralNames([<DNSName(value='www.example.com')>, <DNSName(value='host1.example.com')>, <DNSName(val ue='example.com')>])>)>)>

Create a CSR

>>> csr = cnert.CSR()

>>> csr.pem
b'-----BEGIN CERTIFICATE REQUEST-----\nMIICWzCCAUMCAQAwFjEUMBIGA1UEAwwLZXhhbXBsZS5jb20wggEiMA0GCSqGS
Ib3\nDQEBAQUAA4IBDwAwggEKAoIBAQCzMgKx18z/G6WFc7ULVZS8gEHYW7jNmBM0wvIG\nCFkGu8UzPZL/dHpb4UAAA3kJ+MpYUYvjAuLxoh
6RarbkfChGSGvrJVzbNJtj0axL\n3ryyZ4WhSPFGQnLCze/CsnZbZV+a2B6kdnpb2xge+pa8owGSp3jQRlqFy03tBhAK\nrXlQ/XNQ9xN7CDM
8tHyPwJtl2wHegg7zHI/pjGGoXxfz1E6257+lgIL8lIooRpgu\nXPTp/ZCBumBlNjTtITcL8AUFuRfEAXvLRjVFXh4oOBBddQUNvGwKBUZDqC
zNoxRz\ntcd4ZeWL3BrwkRsKZ6gnV3rxhoIk3Bysf2ckeE1kKIdHQ+jHAgMBAAGgADANBgkq\nhkiG9w0BAQsFAAOCAQEAcintXa9ErBuCNw8
pNftb3ENKMC7+AhNQ6wchBvTZw6Kp\nA30kV/LEjSHSGoL1rNYweUqA2NXyKT3Nm8ey4cfgpqc1L+NQfO65Hbf+PODwgIcr\nAB5fW7xZwei/
weCoxYoznknv/9UN9IHT/3itFCO6XYdW7+TbbZ2Hfqo/fZHadZpQ\ntCndu3zTyEZfa2uw2OXapDgfpI16WiF1MGEf67b+8WoXfGW/bbzTfRy
qX4tfqS2I\nRATog8sQheC1zhh9LTGRYFSqEd15RPIDuXcc902YEXQrbniVF2TwV/qtKqqqcvZu\nPsOCzwRJq87N39XWH1EInVFfftHOTWn9
HatP/+RbrQ==\n-----END CERTIFICATE REQUEST-----\n'

>>> csr.subject_attrs.COMMON_NAME
'example.com'