Recently, Red Hat announced the technical preview of Red Hat Trusted Artifact Signer which is a production-ready deployment of the Sigstore project for enterprise use. In this article, we will learn how to use Trusted Artifact Signer when signing, attesting and verifying a container image with cosign and Enterprise Contract (EC).
Before starting, we must deploy Trusted Artifact Signer on our Red Hat OpenShift cluster by following Chapter 1 of the Deployment Guide. Be sure to also run the source ./tas-env-variables.sh script to set up the shell variables (URLs) to the Sigstore services endpoints (Fulcio, Rekor etc).
Once Trusted Artifact Signer is up and running, we no longer need to be logged in to the OpenShift cluster:
oc logout
Next, we will need a container image to play with. This can be any container image in any Open Container Initiative (OCI) registry, e.g. quay.io. The only requirement is that we must have write access to the repository. For convenience, we will set a shell variable with the image reference:
IMAGE=quay.io/lucarval/rhtas-test@sha256:6b95efc134c2af3d45472c0a2f88e6085433df058cc210abb2bb061ac4d74359
That’s it for the prerequisites. Things are about to get exciting.
Let’s get signing
First, let’s tell cosign and EC to use Trusted Artifact Signer instead of the publicly available sigstore deployment:
cosign initialize --mirror=$TUF_URL --root=$TUF_URL/root.json
Now we are ready to sign the image:
cosign sign -y --fulcio-url=$FULCIO_URL --rekor-url=$REKOR_URL \
--oidc-issuer=$OIDC_ISSUER_URL $IMAGE
The command above will cause your default web browser to open to a login page. This is the Keycloak instance created during the Trusted Artifact Signer deployment. Login with the credentials of an existing user.
The image should now be signed.
Before verifying the image signature, let’s also create a Supply-chain Levels for Software Architects (SLSA) Provenance attestation and associate it with the container image. Usually, the system responsible for building the container image is also responsible for doing this. Here, we simply create a sample SLSA Provenance:
echo '{
"builder": {
"id": "https://localhost/dummy-id"
},
"buildType": "https://localhost/dummy-type",
"invocation": {},
"buildConfig": {},
"metadata": {
"buildStartedOn": "2023-09-25T16:26:44Z",
"buildFinishedOn": "2023-09-25T16:28:59Z",
"completeness": {
"parameters": false,
"environment": false,
"materials": false
},
"reproducible": false
},
"materials": []
}
' > predicate.json
Now we sign and attach the predicate above as an attestation to the image.
cosign attest -y --fulcio-url=$FULCIO_URL \
--rekor-url=$REKOR_URL \
--oidc-issuer=$OIDC_ISSUER_URL \
--predicate predicate.json \
--type slsaprovenance $IMAGE
Just as before, a web browser will appear. Authentication happens automatically as you are already logged in.
Finally, we will use EC to verify the signature and attestation of the image.
ec validate image --image $IMAGE \
--certificate-identity-regexp '.*' \
--certificate-oidc-issuer-regexp '.*' \
--output yaml --show-successes
The command above should display a detailed report of the verifications performed as well as detailed information about the signatures.
NOTE: When verifying a container image, avoid using a loose regular expression like the example above. Instead, be as specific as possible to be sure the signatures match the expected identity.
I hope you enjoyed this high level overview showcasing how to use Red Hat Trusted Artifact Signer with cosign and Enterprise Contract!
Sobre o autor
Luiz Carvalho is a Principal Software Engineer at Red Hat. He has years of experience in container build systems and supply chain security. He has been involved in various open source projects, including Tekton Chains and cosign. More recently, he has worked with his team on building a mechanism to standardize the process of validating supply chain security with the Enterprise Contract.
Navegue por canal
Automação
Últimas novidades em automação de TI para empresas de tecnologia, equipes e ambientes
Inteligência artificial
Descubra as atualizações nas plataformas que proporcionam aos clientes executar suas cargas de trabalho de IA em qualquer ambiente
Nuvem híbrida aberta
Veja como construímos um futuro mais flexível com a nuvem híbrida
Segurança
Veja as últimas novidades sobre como reduzimos riscos em ambientes e tecnologias
Edge computing
Saiba quais são as atualizações nas plataformas que simplificam as operações na borda
Infraestrutura
Saiba o que há de mais recente na plataforma Linux empresarial líder mundial
Aplicações
Conheça nossas soluções desenvolvidas para ajudar você a superar os desafios mais complexos de aplicações
Programas originais
Veja as histórias divertidas de criadores e líderes em tecnologia empresarial
Produtos
- Red Hat Enterprise Linux
- Red Hat OpenShift
- Red Hat Ansible Automation Platform
- Red Hat Cloud Services
- Veja todos os produtos
Ferramentas
- Treinamento e certificação
- Minha conta
- Suporte ao cliente
- Recursos para desenvolvedores
- Encontre um parceiro
- Red Hat Ecosystem Catalog
- Calculadora de valor Red Hat
- Documentação
Experimente, compre, venda
Comunicação
- Contate o setor de vendas
- Fale com o Atendimento ao Cliente
- Contate o setor de treinamento
- Redes sociais
Sobre a Red Hat
A Red Hat é a líder mundial em soluções empresariais open source como Linux, nuvem, containers e Kubernetes. Fornecemos soluções robustas que facilitam o trabalho em diversas plataformas e ambientes, do datacenter principal até a borda da rede.
Selecione um idioma
Red Hat legal and privacy links
- Sobre a Red Hat
- Oportunidades de emprego
- Eventos
- Escritórios
- Fale com a Red Hat
- Blog da Red Hat
- Diversidade, equidade e inclusão
- Cool Stuff Store
- Red Hat Summit