ACME

ENTERPRISE EDITION This is an EJBCA Enterprise Edition (EE) feature.

    ACME Overview

    The Automatic Certificate Management Environment (ACME) is a protocol that a Certificate Authority (CA) and an applicant can use to automate the process of verification and certificate issuance.

    Supported Operations

    The ACME RFC Internet-Draft is a working document. The EJBCA implementation currently complies with IETF - ACME Draft 12.

    Operation

    URL

    Description

    Draft Reference

    directory

    /ejbca/acme/directory

    Provides a JSON object describing the other commands.

    7.1.1

    newNonce

    /ejbca/acme/newNonce

    Before any POST action is performed, the client needs to retrieve an anti-replay nonce from the server.

    7.2

    newAccount

    /ejbca/acme/newAccount

     

    7.3

    updateAccount

    /ejbca/acme/acct/{accountId}

     

    7.3.2

    newOrder

    /ejbca/acme/newOrder

     

    7.4

    challengeResponse

    /ejbca/acme/acct/{accountId}/authz/{authorizationId}/{challengeId}

     

    7.5.1

    newAuthz

    /ejbca/acme/newAuthz

    Only if Pre-Authorization Allowed is enabled in the Alias configuration.

    7.4.1

    finalizeOrder

    /ejbca/acme/acct/{accountId}/orders/{orderId}/finalize

     

    7.1.3

    revokeCert

    /ejbca/acme/revokeCert

     

    7.6

    keyChange

    /ejbca/acme/keyChange

     

    7.3.6

    URL Endpoints and Aliases

    The ACME service is available on the following URLs.

    Default alias with client authentication

    https://<server>:8443/ejbca/acme/directory

    Default alias without client authentication

    https://<server>:8442/ejbca/acme/directory

    Custom alias <alias_name> with client authentication

    https://<server>:8443/ejbca/acme/directory?configurationId=<alias_name>

    Custom alias <alias_name> without client authentication

    https://<server>:8442/ejbca/acme/directory?configurationId=<alias_name>

    EJBCA Specifics

    • Approvals in EJBCA for certificate issuance and revocation cannot be used with ACME.

    • All ACME operations are performed over the peers protocol. Thus it is perfectly possible to use an external RA running EJBCA as an ACME proxy.

    • Validators for CAA checking etc. are configured as described in Validators.

    • You need to set up separate aliases for each end entity profile/certificate profile and CA.

    Configuration

    Enabling ACME

    The ACME protocol is by default disabled. To enable the service, go to Admin Web > System Configuration > Protocol Configuration and select Enable for ACME.

    images/download/attachments/16237454/Screen_Shot_2018-08-02_at_14.41.27.png

    Managing ACME Configurations

    Much like other protocols in EJBCA, several different ACME configurations can be maintained at the same time using aliases.

    To configure ACME, select ACME Configuration under the System Configuration menu.

    images/download/attachments/16237454/Screen_Shot_2018-08-02_at_14.44.14.png

    Global Fields

    The following fields are defined globally for all ACME operations.

    Field

    Description

    Default ACME Configuration

    The configuration to use if the specified alias doesn't exist.

    Replay Nonce Validity Number

    Defines the validity in milliseconds of a generated replay nonce.

    Alias Specific Fields

    images/download/attachments/16237454/Screen_Shot_2018-08-02_at_15.43.57.png

    The following table lists ACME specific fields for each individual alias.

    Field

    Description

    End Entity Profile

    The end entity profile to use for end entities enrolled using this alias. The CA signing the certificate is the default CA of this end entity profile, and the certificate profile used for the certificate is the default certificate profile of this end entity profile.

    Pre-Authorization Allowed

    Pre-authorization, as defined in section 7.4.1 of the draft.

    Wildcard Certificate Issuance Allowed

    Whether this alias can be used to issue certificates with wildcard DNS names in their SANs. See section 7.1.3 of the draft.

    Site URL

    URL to a website describing this CA. Optional. See section 7.1.1 of the draft.

    Terms of Service URL

    URL to your terms of service for ACME. Optional. See section 7.1.1 of the draft.

    Require client approval for Terms of Service changes

    Specifies whether users must approve the new version if the Terms of Service URL is changed.

    DNS Resolver

    A specified DNS resolver, used when processing dns01 challenges.

    DNS Port

    Port used for DNS communications.

    DNSSEC Trust Anchor

    The ICANN trust anchor, configurable should it ever change.

    The optional feature External Account Binding is not supported in this release. The corresponding field in the directory output (externalAccountRequired) is disabled by default and not editable.

    End Entity Profile Configuration

    The following settings should be used for an end entity profile used with ACME.

    Field

    Value

    Username

    Auto-generated

    Password (or Enrollment Code)

    Leave empty

    Batch generation (clear text pwd storage)

    Use

    End Entity E-mail

    Use, Required, Modifiable

    Subject DN Attributes

     

    CN, Common name

    Required, Modifiable

    Default Certificate Profile

    <The certificate profile to use>

    Default CA

    <The CA signing the certificate>

    Default Token

    User Generated

    Authentication and Validation

    EJBCA currently supports the two validation methods http01 and dns01, defined in section 8 of the draft.

    HTTP Challenge (http01)

    If the client chooses to use the http01 challenge type, it intends to prove that it controls the domain requested in the certificate by provisioning a resource under the same domain name. As per the draft, EJBCA will send out a challenge to the client, which the client will sign using its private key and provide on the domain in a known location for EJBCA to retrieve. EJBCA will then be able to use the public key provided in the original request to verify domain control.

    DNS Challenge (dns01)

    If the client chooses to use the dns01 challenge type, it instead obligates itself to supply a TXT record containing the same token response as described above. As per the draft, DNSSEC is required for dns01 challenges.

    Compatibility with ACME Clients

    EJBCA is compatible with the following ACME clients (taken from Letsencrypt's list of compatible ACME clients):

    EJBCA ACME with Certbot

    Certbot used to be Let's Encrypt's official client but is now maintained by the Electronic Frontier Foundation. It is one of the most used ACME clients, supporting issuance, renewal and revocation operations, which are all supported by EJBCA. For more information, refer to the Certbot Documentation.

    Certbot by default uses Let's Encrypts servers. To specify an alternative server URL, use the --server option:

    --server https://localhost:8442/ejbca/acme/directory

    Note that you can also use the server option in cli.ini.

    Certbot Examples

    The following HTTP Validation and DNS Validation examples assume that a Ubuntu machine with JBoss 6.4 is used and that EJBCA is accessible under https://localhost:8442 public HTTPS, using certbot 0.26.1.

    First, run the following command in the command line to ensure that a connection to the ACME server is up and running:

    curl -k https://localhost:8442/ejbca/acme/directory

    The successful output of the above command should be as follows (showing the resources available in the EJBCA ACME server), otherwise the scenarios will fail:

    {"newNonce":"https://localhost:8442/ejbca/acme/newNonce","newAccount":"https://localhost:8442/ejbca/acme/newAccount","newOrder":"https://localhost:8442/ejbca/acme/newOrder","revokeCert":"https://localhost:8442/ejbca/acme/revokeCert","keyChange":"https://localhost:8442/ejbca/acme/keyChange","meta":{"termsOfService":"https://example.com/acme/terms","website":"https://www.example.com/","caaIdentities":[],"externalAccountRequired":false}}

    HTTP Validation Example

    This example covers setting up a local HTTP server, issuing a certificate for an identifier using HTTP validation, and also shows how to revoke the certificate.

    1) Setup a Local HTTP Server

    The following describes setting up a local HTTP server. Note that you can optionally use the temporary web server (or any other supported HTTP server plugins) provided by Certbot. For more information, refer to the Certbot Documentation on Getting certificates (and choosing plugins).

    Follow the steps below to setup a local HTTP server (for example Apache with the default working directory /var/www/html):

    1. Add the following virtual host under /etc/apache2/sites-available/example.com.conf:

      <VirtualHost *:80>
      ServerName example.com
       
      DocumentRoot "/var/www/html/"
       
      </VirtualHost>


    2. Enable the site using the a2ensite command:

      sudo a2ensite example.com


    3. Reload the Apache configuration using the reload command:

      sudo service apache2 reload


    4. Next, restart Apache:

      sudo /etc/init.d/apache2 restart


    5. Then add the following line to your /etc/hosts file:

      127.0.0.1 example.com


    2) Obtain a Certificate using Certbot

    To issue a certificate for an identifier (in this case example.com) using Certbot, do the following. It requires that you have Certbot installed on your machine, and that EJBCA is up and running with ACME enabled and with an ACME alias configured with an appropriate end entity profile.

    1. To obtain the certificate, run the Certbot certonly sub command:

      sudo certbot --no-verify-ssl certonly --webroot -w /var/www/html/ -d example.com --server https://localhost:8442/ejbca/acme/directory

      Alternatively, to instead issue a certificate for a wildcard domain, enable the Wildcard Certificate Issuance Allowed option on the ACME Configuration Alias page (see Alias Specific Fields) and run the Certbot certonly sub command providing a wildcard domain as identifier:

      sudo certbot --no-verify-ssl certonly --webroot -w /var/www/html/ -d *.example.com --server https://localhost:8442/ejbca/acme/directory

    2. If successful, a message similar to the following is displayed:

      IMPORTANT NOTES:
       - Congratulations! Your certificate and chain have been saved at:
       /etc/letsencrypt/live/example.com/fullchain.pem
       Your key file has been saved at:
       /etc/letsencrypt/live/example.com/privkey.pem
       
        Your cert will expire on 2020-08-21. To obtain a new or tweaked version of this certificate in the future, 
        simply run certbot again. To non-interactively renew *all* of your certificates, run "certbot renew"

      If you run the same certbot certonly command twice, Certbot asks if you want to renew the current certificate. To allow renewal using the same Subject DN name, the Enforce Unique DN field on the Edit CA page must be cleared. For more information, see CA Fields.

    3. To verify the obtained certificate, go to the EJBCA Admin Web, search for End Entities, and check that there is a End Entity certificate with the status Generated and CN = example.com.

      The error message The client lacks sufficient authorization :: The client lacks sufficient authorization indicates a conflict between the new account creation and existing ACME accounts. To resolve, remove everything under /etc/letsencrypt/live, /etc/letsencrypt/accounts and /etc/letsencrypt/keys and try again.

    3) Revoke Certificate

    This example covers how to revoke the certificate issued in the previous step.

    1. To revoke the issued certificate, run the Certbot revoke command:

      sudo certbot --no-verify-ssl --server https://localhost:8442/ejbca/acme/directory revoke --cert-path /etc/letsencrypt/live/example.com/fullchain.pem
    2. When asked to verify deleting the issued certificate, reply with Y. The following success message displays:

      Congratulations! You have successfully revoked the certificate that was located at /etc/letsencrypt/live/example.com/fullchain.pem
    3. To verify, go to EJBCA Admin Web and check the status for the corresponding End Entity certificate and ensure that it is revoked.

    DNS Validation Example

    This example covers verifying your DNS server setup, issuing a certificate for an identifier using Domain Name System Security Extensions ( DNSSEC ) validation, and also shows how to revoke the certificate.

    1) Verifying DNS Server Setup

    Ensure that you have a DNS server setup which you can add TXT records to. In this example, dnsmasq is used, included in most Linux distributions.

    The EJBCA ACME server currently supports DNSSEC validation and this example uses allow.klaan.nu to be able to pass DNSSEC validation.

    2) Obtain a Certificate using Certbot

    To issue a certificate for an identifier (in this case allow.klaan.nu) using Domain Name System Security Extensions ( DNSSEC ) validation , do the following.

    1. To obtain the certificate, run the Certbot certonly sub command and specify the --manual flag to run Certbot interactively and allow preparing the DNS server with the DNS challenge offered by the ACME server:

      sudo certbot --no-verify-ssl certonly --manual --preferred-challenges=dns -d allow.klaan.nu --server https://localhost:8442/ejbca/acme/directory

      Alternatively, to instead issue a certificate for a wildcard domain, enable the Wildcard Certificate Issuance Allowed option on the ACME Configuration Alias page (see Alias Specific Fields) and run the Certbot certonly sub command providing a wildcard domain as identifier:

      sudo certbot --no-verify-ssl certonly --manual --preferred-challenges=dns -d *.allow.klaan.nu --server https://localhost:8442/ejbca/acme/directory
    2. Agree to your IP being logged by replying Yes to the following:

      Are you OK with your IP being logged?
      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      (Y)es/(N)o:
    3. Certbot displays the TXT record challenge offered by the ACME server which have to be provisioned in the DNS server. Before pressing Enter, run the following command to provision the TXT record in dnsmasq:

      sudo dnsmasq --port="1453" --txt-record="_acme-challenge.allow.klaan.nu, pULO3RjCbzqjWH0JK2FQ5BDe-5SI2Eo2Vn1l_fmrtdk" --listen-address="127.0.0.1" --interface="lo" --bind-interfaces

      The port number used above is just an example. Note that the port number must equal the port set for the ACME Alias currently used by the EJBCA ACME server, configured in Admin Web>System Configuration>ACME Configuration. In addition, the DNS Resolver field needs to be set to localhost in the ACME Configuration Alias page, see Alias Specific Fields.

    4. After running the above command, press Enter in the Certbot command prompt to continue. A message similar to the following is displayed for a successful certificate issuance:

      IMPORTANT NOTES:
       - Congratulations! Your certificate and chain have been saved at:
         /etc/letsencrypt/live/allow.klaan.nu/fullchain.pem
         Your key file has been saved at:
         /etc/letsencrypt/live/allow.klaan.nu/privkey.pem
         
         Your cert will expire on 2020-08-21. To obtain a new or tweaked version of this certificate in the future, 
         simply run certbot again. To non-interactively renew *all* of your certificates, run "certbot renew"
    5. To verify that the certificate is issued in EJBCA, go to the EJBCA Admin Web, and check that the End Entity Search page includes a row with CN = allow.klaan.nu and a valid certificate.

    3) Revoke Certificate

    This example covers how to revoke the certificate issued in the previous step.

    1. To revoke the issued certificate, run the Certbot revoke command:

      sudo certbot --no-verify-ssl --server https://localhost:8442/ejbca/acme/directory revoke --cert-path /etc/letsencrypt/live/allow.klaan.nu/fullchain.pem
    2. If successful, the following message displays:

      Congratulations! You have successfully revoked the certificate that was located at /etc/letsencrypt/live/allow.klaan.nu/fullchain.pem
    3. To verify, ensure that the certificate is revoked with the reason Unspecified by checking its status in the EJBCA Admin Web End Entity Search page.

    EJBCA ACME with PJAC

    Porunov Java ACME Client (PJAC) is an application based on acme4j , a Java ACME library implementation. To try out EJBCA with PJAC, just follow these guides for Example scenarios.

    EJBCA is tested with the following PJAC flows:

    • Get a certificate for multiple domains

    • Renew a certificate for multiple domains

    • Get a wildcard certificate

    • Revoke certificate

    • Deactivate account

    • HTTP01 and DNS01 challenge types

    images/s/en_GB/7202/8bb4a7d7a43e6723fe7875221f32b3124c55e6e1/_/images/icons/emoticons/warning.png Note that you need to configure PJAC to have the EJBCA instance as its ACME service, by adding the following extra parameter to every acme_client.jar command execution:

    -u https://localhost:8442/ejbca/acme/directory

    For example, the 5th step in the Get a certificate for multiple domains guide would look like this:

    Step 5 from the PJAC guide
    java -jar acme_client.jar --command register -a /etc/pjac/account.key
    --with-agreement-update -u https://localhost:8442/ejbca/acme/directory

    EJBCA ACME with ACME Tiny

    1. Clone the repository:

      git clone https://github.com/diafygi/acme-tiny.git
    2. Change EJBCA ACME URLs:

      -DEFAULT_CA = "https://acme-v02.api.letsencrypt.org" # DEPRECATED! USE DEFAULT_DIRECTORY_URL INSTEAD
      -DEFAULT_DIRECTORY_URL = "https://acme-v02.api.letsencrypt.org/directory"
      +
      +DEFAULT_CA = "https://{ejbca_url}:8442" # DEPRECATED! USE DEFAULT_DIRECTORY_URL INSTEAD
      +DEFAULT_DIRECTORY_URL = "https://{ejbca_url}:8442/ejbca/acme/directory"
    3. Prepare input for ACME:

      # Generate private key
      openssl genrsa 4096 > account.key
      # Generate CSR
      openssl req -new -sha256 -key account.key -subj "/emailAddress=acme_test@primekey.com/CN=my.acme" > account.csr
    4. Launch ACME Tiny (Tested with Python2):

      sudo python acme_tiny.py --account-key ./account.key --csr ./account.csr --acme-dir ./acme-dir/ --contact 'mailto:acme@primekey.com' > ./signed_chain.crt

    where --acme-dir ./acme-dir/ might be integrated and/or point to your current web server, for example Apache2 /var/www/html/.well-known/acme-challenge/.

    Workflow Examples

    The following lists ACME calls to perform in order to get a certificate.

    getDirectory request

    Verifies that the EJBCA ACME service is up and running.

    GET /acme/directory HTTP/1.1
     
    {
    "newNonce":"https://footrust.local:8443/ejbca/acme/newNonce",
    "newAccount":"https://footrust.local:8443/ejbca/acme/newAccount",
    "newOrder":"https://footrust.local:8443/ejbca/acme/newOrder",
    "newAuthz":"https://footrust.local:8443/ejbca/acme/newAuthz",
    "revokeCert":"https://footrust.local:8443/ejbca/acme/revokeCert",
    "keyChange":"https://footrust.local:8443/ejbca/acme/keyChange",
    "meta":{
    "termsOfService":"https://footrust.com/acme/terms",
    "website":"https://footrust.com",
    "caaIdentities":[
    "footrust.com"
    ],
    "externalAccountRequired":false
    }
    }

    newAccount

    Creates a new ACME account to EJBCA. EJBCA uses a public key to verify the JWS (that is, the jwk element of the JWS header) to authenticate future requests from the account. EJBCA supports RSA and EC key types.

    POST https://localhost:8442/ejbca/acme/newAccount HTTP/1.1
    Content-Type: application/jose+json
     
    {
    "protected": base64url({
    "alg": "ES256",
    "jwk": {...},
    "nonce": "6S8IqOGY7eL2lsGoTZYifg",
    "url": "https://example.com/acme/newAccount"
    }),
    "payload": base64url({
    "termsOfServiceAgreed": true,
    "contact": [
    "mailto:cert-admin@example.com",
    "tel:+12025551212"
    ]
    }),
    "signature": "RZPOnYoPs1PhjszF...-nh6X1qtOFPB519I"
    }

    newOrder request

    To create a new ACME order.

    POST /acme/newOrder HTTP/1.1
    Content-Type: application/jose+json
     
    {
    "protected": base64url({
    "alg": "ES256",
    "kid": "https://example.com/acme/acct/1",
    "nonce": "5XJ1L3lEkMG7tR6pA00clA",
    "url": "https://example.com/acme/new-order"
    }),
    "payload": base64url({
    "identifiers": [
    { "type": "dns", "value": "example.com" }
    ],
    "notBefore": "2016-01-01T00:00:00Z",
    "notAfter": "2016-01-08T00:00:00Z"
    }),
    "signature": "H6ZXtGjTZyUnPeKn...wEA4TklBdh3e454g"
    }

    The newOrder response contains information about challenges. For more information, refer to the section 7.5.1 of the draft.

    newAuthz request

    POST /acme/newAuthz HTTP/1.1
    Host: example.com
    Content-Type: application/jose+json
     
    {
    "protected": base64url({
    "alg": "ES256",
    "jwk": {...},
    "nonce": "uQpSjlRb4vQVCjVYAyyUWg",
    "url": "https://example.com/acme/newAuthz"
    }),
    "payload": base64url({
    "identifier": {
    "type": "dns",
    "value": "example.net"
    }
    }),
    "signature": "nuSDISbWG8mMgE7H...QyVUL68yzf3Zawps"
    }

    challengeResponse request

    To prove to EJBCA's ACME service that you possess control over the domain.

    POST /acme/acct/{accountId}/authz/{authorizationId}/{challengeId} HTTP/1.1
    Content-Type: application/jose+json
     
    {
    "protected": base64url({
    "alg": "ES256",
    "kid": "https://example.com/acme/acct/1",
    "nonce": "Q_s3MWoqT05TrdkM2MTDcw",
    "url": "https://example.com/acme/authz/1234/0"
    }),
    "payload": base64url({}),
    "signature": "9cbg5JO1Gf5YLjjz...SpkUfcdPai9uVYYQ"
    }

    finalizeOrder request

    To generate the certificate.

    POST /acme/acct/{accountId}/orders/{orderId}/finalize HTTP 1.1
    Content-Type: application/jose+json
     
    {
    "protected": base64url({
    "alg": "ES256",
    "kid": "https://example.com/acme/acct/1",
    "nonce": "MSF2j2nawWHPxxkE3ZJtKQ",
    "url": "https://example.com/acme/order/asdf/finalize"
    }),
    "payload": base64url({
    "csr": "MIIBPTCBxAIBADBFMQ...FS6aKdZeGsysoCo4H9P",
    }),
    "signature": "uOrUfIIk5RyQ...nw62Ay1cl6AB"
    }

    The response to the finalizeOrder call is the certificate.

    Status Codes

    HTTP Status Code

    Description

    200

    Success

    201

    Created

    204

    No content

    400

    Bad request

    401

    Unauthorized

    403

    Forbidden

    404

    Not found

    409

    Conflict