Profiles¶

A profile defines default properties, including certificate extensions, for TLS certificates. These properties define who can use the certificate for what purpose, how a peer can validate it and what clients are compatible with the certificates.

django-ca defines a set of default profiles that should be sufficient for most use cases:

Name	Purpose
`client`	Certificate can be used for TLS client authentication.
`enduser`	Certificate can be used for TLS client authentication and code and email signing.
`ocsp`	Certificate can be used for a OCSP responder, marked as automatically generated by default.
`server`	Certificate can be used for both a TLS server and a TLS client.
`webserver`	(default) Certificate can be used for a TLS server but not for TLS client authentication.

You can configure the default profile to use using the CA_DEFAULT_PROFILE setting. You can also add new profiles or modify existing ones using the CA_PROFILES setting.

Using profiles¶

You can use a profile when signing certificates:

When you use the command line:

$ python manage.py sign_cert --client ...

In the Web interface you can select a profile when adding a certificate.

In the Python API:

>>> from django_ca.models import Certificate
>>> Certificate.objects.create_cert(ca, csr, profile='client')

or by even defining a temporary profile just for this certificate:

>>> from django_ca.profiles import Profile
>>> prof = Profile(...)
>>> Certificate.objects.create_cert(ca, csr, profile=prof)

Configure profiles¶

You can add new profiles with the CA_PROFILES setting. The setting a dictionary with the key identifying the certificate and the values configuring various aspects of certificates signed using this profile. A simple profile might look like this:

CA_PROFILES = {
    'example': {  # actually a duplicate of the predefined "client" profile
        'description': _('An example profile.'),
        'extensions': {
            'key_usage': {'value': ['digitalSignature']},
            'extended_key_usage': {'value': ['clientAuth']},
        },
    },
}

After defining a profile, it can be immediately used with the Python API, the Admin web interface (WSGI servers typically need to reload the code to see the new profile) or the command line:

$ python manage.py sign_cert -h
...
profiles:
  Sign certificate based on the given profile. A profile only sets the the default values, options like --key-
  usage still override the profile.

  --client              A certificate for a client.
  --server              A certificate for a server, allows client and server authentication.
  --webserver           A certificate for a webserver.
  --enduser             A certificate for an enduser, allows client authentication, code and email signing.
  --ocsp                A certificate for an OCSP responder.
  --example             An example profile.

Available options¶

There are many available options for a profile, of course all of them are optional:

Option	Default	Description
`add_crl_url`	`True`	Set to `False` if you don’t want the CAs CRL URL added.
`add_issuer_alternative_name`	`True`	Set to `False` if you don’t want the CAs Issuer Alternative Name added.
`add_issuer_url`	`True`	Set to `False` if you don’t want the CAs Issuer URL added.
`add_ocsp_url`	`True`	Set to `False` if you don’t want the CAs OCSP URLs added.
`algorithm`		The algorithm used for signing, defaults to CA_DIGEST_ALGORITHM.
`autogenerated`	`False`	Set to `True` if you want to mark certificates from this profile as automatically generated by default.
`cn_in_san`	`True`	If the CommonName should be added as Subject Alternative Name.
`description`	`''`	Informal text explaining what the profile is.
`expires`		A `timedelta` of when a certificate will expire, if you set an integer it will be interpreted as a number of days. This defaults to CA_DEFAULT_EXPIRES.
`extensions`	`{}`	A dictionary of extensions to add. Please see below for more details.
`issuer_name`	`None`	Set an alternative issuer name from the CA. Note that this will usually break any certificate validation, so this is definitely for experts only.
`subject`		The default subject to use, overrides CA_DEFAULT_SUBJECT.

Configure extensions¶

Many extensions (such as AuthorityKeyIdentifier and BasicConstraints) are added by default since they are required to create a useful certificate. Further extensions (such as the CRLDistributionPoints and AuthorityInformationAccess) are added depending on the values for the CA you are using and the add_{...}_url settings described below.

You can define any extension defined in the documentation in a profile. Use the key as a dictionary key and a dictionary as a value describing the extension. All extensions use a value key to describe the extension value and an optional critical value to describe if the extension is marked as critical. For example, for the KeyUsage extension, use:

CA_PROFILES = {
    'example': {
        # ...
        'extensions': {
            'key_usage': {
               'critical': False,  # usually critical, but not here for some reason
               'value': ['digitalSignature']
            },
        },
    },
}

The `add_..._url` settings¶

By default, certificates will include some extensions based on the CA used to sign it. The CA usually defines CRL and OCSP URLs that can be used to retrieve information if the certificate is still valid. This is usually what you want, but there are some exceptions. For example, a certificate for an OCSP responder should not include the OCSP URL, as it makes no sense to validate the OCSP responder certificate using the OCSP responder itself. The ocsp profile thus already sets add_ocsp_url to False.

If your profile defines a CRLDistributionPoints or AuthorityInformationAccess, CRL, OCSP and Issuer URLs from the CA will be appended if the add_..._url setting is True.

Update existing profile¶

You can update an existing profile the same way as configuring a new profile. Any values will replace existing values. To update the default subject for the (predefined) enduser profile:

CA_PROFILES = {
    'enduser': {
        'subject': '/C=AT/L=Vienna/',  # base for the subject when creating a new cert
    },
}

Note that django-ca also replaces the while extensions value. That means you cannot update one extension from the profile, you’ll have to specify all extensions.

Remove a profile¶

You can remove a predefined profile by just setting the value to None:

CA_PROFILES = {
    'client': None  # we really don't need this one
}