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

Preconfigured profiles

client

Certificates with this profile can be used for TLS client authentication. Use it when the certificate should be used by a client to authenticate itself (not the server).

It defines the following extensions and values:

• KeyUsage: digital_signature

• ExtendedKeyUsage: clientAuth

webserver

Certificates with this profile can be used for TLS server authentication. Use it when the certificate should be used by a server to provide TLS connections, e.g. HTTPS.

Note

The profile name is actually a misnomer, as it cannot be used just for web servers but any server. The certificate could just as well be used by a mail server, MQTT server or anything else.

It defines the following extensions:

server

Certificates with this profile can be used for both TLS client and server authentication. Use it when the certificate should be used by a daemon that both accepts and initiates TLS connections (an example would be a federated XMPP server).

It defines the following extensions and values:

• KeyUsage: digital_signature, key_agreement, key_encipherment

• ExtendedKeyUsage: clientAuth, serverAuth

enduser

Certificates with this profile can be used by users to perform client authentication and sign code and emails.

It defines the following extensions and values:

• KeyUsage: data_encipherment, digital_signature, key_encipherment

• ExtendedKeyUsage: clientAuth, codeSigning, emailProtection

ocsp

Certificates with this profile can be used in an OCSP responder. Automatic creation of OCSP responder keys use this profile.

It defines the following extensions and values:

• KeyUsage: non_repudiation, digital_signature, key_encipherment

• ExtendedKeyUsage: OCSPSigning

• OCSPNoCheck

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:

Python

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"]},
        },
    },
}

YAML

CA_PROFILES:
  example:
    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_DEFAULT_SIGNATURE_HASH_ALGORITHM for RSA/EC keys.
autogenerated	False	Set to True if you want to mark certificates from this profile as automatically generated by default.
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 the subject

The subject in a profile serves as a default value for subjects when signing certificates. You can use the CA_DEFAULT_SUBJECT setting to set a default value for all profiles. If a profile should not set any setting (despite CA_DEFAULT_SUBJECT being set), set False for the subject.

The format used for the subject is the same as the CA_DEFAULT_SUBJECT setting, please refer to the settings documentation for the exact syntax. When signing via the command line or issuing certificates via ACMEv2, the subject will be sorted according to CA_DEFAULT_NAME_ORDER.

When issuing certificates via ACMEv2, the subject of the issued certificate will be the subject of the profile, with the first DNS name requested by the client used as common name. You can configure the profile being used for each certificate authority via the admin interface or via manage.py edit_ca --acme-profile.

When signing certificates via the API, this value is not used, the caller is expected to provide the full subject. When signing certificates via the admin interface, this subject will be the default values in the subject field of the form.

When issuing certificates via the command line, the given subject is merged with the subject of the profile, with explicitly given values taking precedence. For example, given the following configuration:

Python

CA_PROFILES = {
    "example": {
        "description": "Profile defining a custom subject.",
        "subject": (
            ("C", "AT"),
            ("ST", "Vienna"),
        ),
        # ... other options
    }
}

YAML

CA_PROFILES:
  example:
    description: Profile defining a custom subject.
    subject:
      - [ C, AT ]
      - [ ST, Vienna ]
    # ... any other options

… signing a certificate with

$ manage.py sign_cert --subject-format rfc4514 --subject "CN=example.com" ...

will give the certificate a subject of C=AT,ST=Vienna,CN=example.com. If you sign with

$ manage.py sign_cert --subject-format rfc4514 --subject "ST=Styria,L=Graz,CN=graz.example.com" ...

you will get C=AT,ST=Styria,L=Graz,CN=graz.example.com as a subject.

Configure extensions

Many extensions (such as the Authority Key Identifier and Basic Constraints extensions) are added by default since they are required to create a useful certificate. Further extensions (such as the CRL Distribution Points and Authority Information Access) are added depending on the values for the CA you are using and the add_{...}_url settings described below.

You can define any extension in a profile with a dictionary.

Use the key from EXTENSION_KEYS as a dictionary key and a dictionary as a value describing the extension.

The dictionary has an optional critical key. If it is not defined, the critical value will come from EXTENSION_DEFAULT_CRITICAL.

All extensions use a value key to describe the extension value. It is usually a dict for convenience, but can also be a Extension or ExtensionType for convenience (or special cases). For example, for the Key Usage extension, use:

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

Find how to specify the value key for the most important extensions below.

Authority Information Access

Key: authority_information_access

Note

This extension usually comes from the certificate authority and is not usually set in a profile.

The format is based on AuthorityInformationAccessModel. The value is a list of access descriptions. Each consists of an access_method and an access_location:

Python

CA_PROFILES = {
    "example-profile": {
        "extensions": {
            "authority_information_access": {
                "value": [
                    {
                        "access_method": "ocsp",
                        "access_location": {
                            "type": "URI",
                            "value": "http://ocsp.example.com",
                        },
                    },
                    {
                        "access_method": "ca_issuers",
                        "access_location": {"type": "URI", "value": "http://example.com"},
                    },
                ],
            }
        },
    },
}

YAML

access_method can also be an alias from ACCESS_METHOD_TYPES.

CA_PROFILES:
  example-profile:
    extensions:
      authority_information_access:
        value:
        - access_location:
            type: URI
            value: http://ocsp.example.com
          access_method: 1.3.6.1.5.5.7.48.1
        - access_location:
            type: URI
            value: http://example.com
          access_method: 1.3.6.1.5.5.7.48.2

If you do specify the extension in a profile, its access descriptions will be merged with those from the certificate authority if you create a certificate from the command line or via ACMEv2 (unless the profile specifies add_ocsp_url=False and/or add_issuer_url=False). If you create a certificate via the admin interface, selecting the profile will set the value for this extension (profiles are only used to fill the form, not when actually signing the certificate).

Certificate Policies

Key: certificate_policies

Note

This extension usually comes from the certificate authority and is not usually set in a profile.

The format is based on CertificatePoliciesModel. The value is a list of policy information objects. Each consists of a policy_identifier (a dotted string for an OID) and an optional list of policy_qualifier objects.

A policy_qualifier is a list of either strings (usually a certificate practice statement) or a user notice object. Please see the model information for these more exotic use cases.

Python

CA_PROFILES = {
    "example-profile": {
        "extensions": {
            "certificate_policies": {
                "value": [
                    {"policy_identifier": "2.5.29.32.0"},
                    {
                        "policy_identifier": "1.3.6.1.5.5.7.2.1",
                        "policy_qualifiers": [
                            "https://ca.example.com/cps",
                            {"explicit_text": "my text"},
                        ],
                    },
                ],
            }
        }
    }
}

YAML

CA_PROFILES:
  example-profile:
    extensions:
      certificate_policies:
        value:
        - policy_identifier: 2.5.29.32.0
        - policy_identifier: 1.3.6.1.5.5.7.2.1
          policy_qualifiers:
          - https://ca.example.com/cps
          - explicit_text: my text

When issuing certificates via the command-line, not all of the possible values can be represented. You can set a full value either here or by setting the sign_certificate_policies model field of CertificateAuthority.

CRL Distribution Points

Key: crl_distribution_points

Note

This extension usually comes from the certificate authority and is not usually set in a profile.

The format is based on CRLDistributionPointsModel. The value is a list of distribution point objects. In it’s (by far) most common form, it has only a full_name with an URI where the CRL can be downloaded.

Other fields of a distribution point object are relative_name (an RDN), crl_issuer (a list of general names) and reasons (a set of reasons). At least one of full_name and relative_name, other values are optional. As with any name or RDN, the OID may also use an alias from NAME_OID_TYPES.

This example sets two distribution points, a common one (only a full name) and one demonstrating all the other fields.

Python

CA_PROFILES = {
    "example-profile": {
        "extensions": {
            "crl_distribution_points": {
                "value": [
                    {
                        "full_name": [
                            {"type": "URI", "value": "https://ca.example.com/crl"}
                        ],
                    },
                    {
                        "relative_name": [{"oid": "commonName", "value": "example.com"}],
                        "crl_issuer": [
                            {"type": "URI", "value": "https://ca.example.com/issuer"}
                        ],
                        "reasons": ["key_compromise"],
                    },
                ],
            }
        }
    }
}

YAML

CA_PROFILES:
  example-profile:
    extensions:
      crl_distribution_points:
        value:
        - full_name:
          - type: URI
            value: https://ca.example.com/crl
        - crl_issuer:
          - type: URI
            value: https://ca.example.com/issuer
          reasons:
          - key_compromise
          relative_name:
          - oid: 2.5.4.3
            value: example.com

If you do specify the extension in a profile, the value from the certificate authority will take precedence over any value from the profile (unless the profile specifies add_crl_url=False).

Extended Key Usage

Key: extended_key_usage

The value is a list of extended key usages as defined in RFC 5280, section 4.2.1.12. Alternatively you can also pass any valid OID as dotted string. For example:

Python

CA_PROFILES = {
    "example-profile": {
        "extensions": {
            # NOTE: "1.3.6.1.5.5.7.3.1" is equivalent to "serverAuth", but any valid
            # dotted string can be given here.
            "extended_key_usage": {"value": ["clientAuth", "1.3.6.1.5.5.7.3.1"]},
        }
    }
}

YAML

Values can be a dotted string or a name (e.g. "clientAuth").

CA_PROFILES:
  example-profile:
    extensions:
      extended_key_usage:
        value:
        - 1.3.6.1.5.5.7.3.2
        - 1.3.6.1.5.5.7.3.1

Freshest CRL

Key: freshest_crl

Note

This extension usually comes from the certificate authority and is not usually set in a profile.

The syntax is the same as for the CRL Distribution Points extension.

Key Usage

Key: key_usage

The value is a list of key usages as defined in RFC 5280, section 4.2.1.3. Example:

Python

CA_PROFILES = {
    "example-profile": {
        "extensions": {"key_usage": {"value": ["keyAgreement", "keyEncipherment"]}}
    }
}

YAML

CA_PROFILES:
  example-profile:
    extensions:
      key_usage:
        value:
        - key_agreement
        - key_encipherment

OCSP No Check

Key: ocsp_no_check

The value is optional, as the extension has no value (besides being present).

Python

from typing import Any

CA_PROFILES: dict[str, dict[str, Any]] = {
    "example-profile": {
        "extensions": {
            "ocsp_no_check": {},
        }
    }
}

YAML

CA_PROFILES:
  example-profile:
    extensions:
      ocsp_no_check: {}

TLS Feature

Key: tls_feature

The value is a list of features as defined in RFC 7633 (so status_request and status_request_v2). For convenience, OCSPMustStaple and MultipleCertStatusRequest is also supported. Example:

Python

CA_PROFILES = {
    "example-profile": {
        "extensions": {
            "tls_feature": {
                "value": ["status_request"],
            }
        }
    }
}

YAML

CA_PROFILES:
  example-profile:
    extensions:
      tls_feature:
        value:
        - status_request

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 CRL Distribution Points or Authority Information Access extension, 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 whole 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
}