Managing certificates

All certificate operations can be done via the command line. You do not have to use this interface, all functionality is also available via the Web interface, if it has access to the private key of the certificate authority.

Index of commands

To manage certificate, use the following commands:

Command Description
cert_watchers Add/remove addresses to be notified of an expiring certificate.
dump_cert Dump a certificate to a file.
import_cert Import an existing certificate.
list_certs List all certificates.
notify_expiring_certs Send notifications about expiring certificates to watchers.
revoke_cert Revoke a certificate.
sign_cert Sign a certificate.
view_cert View a certificate.

Like all subcommands, you can run <subcomand> -h to get a list of availabble parameters.

Signing certificates

Signing certificates is done using sign_cert. The only requirements are that you provide either a full subject and/or one or more subjectAltNames. Obviously, you also need to create at least one certificate authority first (documentation).

Like any good certificate authority, django-ca never handles private keys of signed certificates. Instead, you sign certificates from a Certificate Signing Request (CSR) that you generate from the private key. Using the OpenSSL command-line tools, you can create a CSR on the host that should use the certificate:

$ openssl genrsa -out example.key 4096
$ openssl req -new -key example.key -out example.csr -utf8

Next, simply copy the CSR file (example.csr in the above example) to the host where you installed django-ca. You can now create a signed certificate using:

$ python sign_cert --alt --csr example.csr --out

If you have defined multiple CAs, you also have to name the CA:

$ python list_cas
4E:1E:2A:29:F9:4C:45:CF:12:2F:2B:17:9E:BF:D4:80:29:C6:37:C7 - Root CA
32:BE:A9:E8:7E:21:BF:3E:E9:A1:F3:F9:E4:06:14:B4:C4:9D:B2:6C - Child CA
$ python sign_cert --ca 32:BE:A9 --alt --csr example.csr --out

Subject and subjectAltName

The Certificate’s Subject (that is, it’s CommonName) and the names given in the subjectAltName extension define where the certificate is valid.

The CommonName is usually added to the subjectAltName extension as well and vice versa. This means that these two will give the same CommonName and subjectAltName:

$ python sign_cert --subject /C=AT/.../
$ python sign_cert --alt

A given CommonName is only added as subjectAltName if it is a valid name. If you give multiple names via --alt but no CommonName, the first one will be used as CommonName. Names passed via alt are parsed as names, so you can also use e.g.:

$ python sign_cert --alt IP:

You can also disable adding the CommonName as subjectAltName:

$ python sign_cert --cn-not-in-san --subject /C=AT/.../

… this will only have “” but not as subjectAltName.

Using profiles

Certificates have extensions that define certain aspects of how/why/where/when a certificate can be used. Some extensions are added based on how the Certificate Authority is configured, e.g. CRL/OCSP URLs. Extensions that define for what purposes are a certificate can be used can be configured on a per-certificate basis.

The easiest way is to use profiles that define what extensions are added to any certificate. django-ca adds these predefined profiles:

Name Purpose
client Allows the certificate to be used on the client-side of a TLS connection.
server Allows the certificate to be used on the client- and server-side of a connections.
enduser Allows client authentication and code and email signing.
webserver Allows only the server-side of a TLS connection, it can’t be used as a client certificate.
ocsp Allows the certificate to be used for signing OCSP responses.

You can add and modify profiles using the CA_PROFILES setting. The default profile is configured by the CA_DEFAULT_PROFILE setting.

Override extensions

You can override some extensions using command-line parameters. Currently, this includes keyUsage, extendedKeyUsage and tlsFeature. In every case, prefixing the value with critical marks the extension as critical (meaning a TLS client that does not understand the extension will reject the connection):

$ python sign_cert \
   --key-usage critical,keyCertSign \
   --ext-key-usage serverAuth,clientAuth \
   --tls-features OCSPMustStaple \

For more information on these extensions, their meaning and typical values, see x509 extensions.

Revoke certificates

To revoke a certificate, use:

$ python list_certs
49:BC:F2:FE:FA:31:03:B6:E0:CC:3D:16:93:4E:2D:B0:8A:D2:C5:87 - localhost (expires: 2019-04-18)
$ python revoke_cert 49:BC:F2:FE:FA:31:03:B6:E0:CC:3D:16:93:4E:2D:B0:8A:D2:C5:87

Expiring certificates

You can add email addresses to be notified of expiring certificates using the --watch parameter:

$ python --sign-cert --watch --watch ...

Or modify to add/remove watchers later:

$ python list_certs
49:BC:F2:FE:FA:31:03:B6:E0:CC:3D:16:93:4E:2D:B0:8A:D2:C5:87 - localhost (expires: 2019-04-18)
$ python cert_watchers -a -r 49:BC:F2