Obtain a Certificate via ACME

The ACME enrollment method lets any ACME client obtain TLS certificates from Hanzo KMS using the ACME protocol. This includes ACME clients like Certbot, cert-manager in Kubernetes using the ACME issuer type, and more.

Hanzo KMS currently supports the HTTP-01 challenge type for domain validation as part of the ACME enrollment method.

Diagram

The following sequence diagram illustrates the certificate enrollment workflow for requesting a certificate via ACME from Hanzo KMS.

sequenceDiagram
  autonumber
  participant ACME as ACME Client
  participant Infis as Hanzo KMS ACME Server
  participant Authz as HTTP-01 Challenge<br/>Validation Endpoint
  participant CA as CA<br/>(Internal or External)

  Note over ACME: ACME Client discovers<br/>Hanzo KMS ACME Directory URL

  ACME->>Infis: GET /directory
  Infis-->>ACME: Directory + nonce + endpoints

  ACME->>Infis: HEAD /new-nonce
  Infis-->>ACME: Return nonce in Replay-Nonce header

  ACME->>Infis: POST /new-account<br/>(contact, ToS agreed)
  Infis-->>ACME: Return account object

  Note over ACME,Infis: Requesting a certificate

  ACME->>Infis: POST /new-order<br/>(identifiers: DNS names)
  Infis-->>ACME: Return order<br/>with authorization URLs

  loop For each authorization (one per DNS name)
    ACME->>Infis: POST /authorizations/:authzId
    Infis-->>ACME: Return HTTP-01 challenge<br/>(URL + token + keyAuth)

    Note over ACME: Client must prove control<br/>over the domain via HTTP

    ACME->>Authz: Provision challenge response<br/>at<br/>/.well-known/acme-challenge/<token>

    ACME->>Infis: POST /authorizations/:authzId/challenges/:challengeId<br/>(trigger validation)

    Infis->>Authz: HTTP GET /.well-known/acme-challenge/<token>
    Authz-->>Infis: Return keyAuth

    Infis-->>ACME: Authorization = valid
  end

  Note over Infis: All authorizations valid → ready to finalize

  ACME->>ACME: Generate keypair locally<br/>and create CSR
  ACME->>Infis: POST /orders/:orderId/finalize<br/>(CSR)

  Infis->>CA: Request certificate issuance<br/>(CSR)
  CA-->>Infis: Signed certificate (+ chain)

  Infis-->>ACME: Return order with certificate URL<br/>(status: valid)

  ACME->>Infis: POST /orders/:orderId/certificate
  Infis-->>ACME: Return certificate<br/>and certificate chain

Guide

In the following steps, we explore an end-to-end workflow for obtaining a certificate via ACME with Hanzo KMS.

Next, follow the guide here to create a certificate profile that will be referenced when requesting a certificate.

The certificate profile specifies which certificate policy and issuing CA should be used to validate an incoming certificate request and issue a certificate; it also specifies the enrollment method for how certificates can be requested against this profile to begin with.

You should specify the certificate policy from Step 2, the issuing CA from Step 1, and the ACME option in the Enrollment Method dropdown when creating the certificate profile.

Finally, follow the guide here to request a certificate against the certificate profile using an ACME client.

The ACME client will connect to Hanzo KMS's ACME server at the ACME Directory URL and authenticate using the EAB Key Identifier (KID) and EAB Secret credentials as part of the ACME protocol.

The typical ACME workflow looks likes this:

The ACME client creates (or reuses) an ACME account with Hanzo KMS using EAB credentials.
The ACME client creates an order for one or more DNS names.
For each DNS name, the ACME client receives an HTTP-01 challenge and provisions the corresponding token response at /.well-known/acme-challenge/<token>.
Once all authorizations are valid, the ACME client finalizes the order by sending a CSR to Hanzo KMS.
Hanzo KMS issues the certificate from the issuing CA on the certificate profile and returns it (plus the chain) back to the ACME client.

ACME clients typically handle renewal by tracking certificate expiration and completing the lifecycle once again to request a new certificate.

We recommend reading more about the ACME protocol here.

Obtain a Certificate via ACME

Diagram

Guide

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