smolcert

smolcert is an implementation of CBOR based certificates inspired by CBOR Profile of X.509 Certificates.

The goal is to have a more compact and easier to parse (especially on embedded systems) certificate format than X.509. The certificate format is specified as CDDL in the file spec.cddl. Generated binary encoded certificates can be verified against this specification.

Currently exist implementations in go and Rust, where the go implementation is the more complete, with support for easy certificate creation, signing and validation. The Rust implementation currently only supports serialization and deserialization of certificates, but no signing, verification etc.

Example

// Create a self signed certificate (i.e. as root certificate)
cert, privateKey, err := SelfSignedCertificate("root",
		time.Now().Add(time.Minute*-1),
		time.Now().Add(time.Minute),
		[]Extension{})
require.NoError(t, err)
err = validateCertificate(cert, cert.PubKey)
assert.NoError(t, err)

Running tests

go test will only run tests which only depend on go. To test more you need specify tags for the test command. If you want to verify that the serilization implementation generates valid data you need to specify the cddltest tag (go test -tags cddltest). Of course tags can be combined (go test -tags rust,cddltest).

If you want to validate that the implementations generate valid CBOR you need to install the cddl tool. This called during tests behind the cddltest flag.