Migration Guide

This document will help you migrate your code to the latest acme4j version.

Migration to Version 3.3.0

  • This version is unable to deserialize resource objects that were serialized by a previous version using Java's serialization mechanism. This shouldn't be a problem, as it was not allowed to share serialized data between different versions anyway.
  • acme4j version 2 is now discontinued. Please migrate your code to version 3. For most clients, it is less work than it seems. 😉

Migration to Version 3.2.0

  • Starting with this version, the CSRBuilder won't add the first domain as common name automatically. This permits the issuance of very long domain names, and should have no negative impact otherwise, as this field is usually ignored by CAs anyway. If you should encounter a problem here, you can use CSRBuilder.setCommonName() to set the first domain as common name manually. Discussion see here.
  • Instead of invoking update() and then handling an AcmeRetryAfterException, you should now prefer to invoke fetch(). It gives an optional retry-after Instant as return value, which makes the retry-after handling less complex. In a future version, update() will be fully replaced by fetch(), and AcmeRetryAfterException will be removed.
  • acme4j was updated to support the latest draft-ietf-acme-ari-03 now. It is a breaking change! If you use ARI, make sure your server supports the latest draft before updating to this version of acme4j.
  • Certificate.markAsReplace() has been removed, because this method is not supported by draft-ietf-acme-ari-03 anymore. To mark an existing certificate as replaced, use the new method OrderBuilder.replaces() now.
  • Certificate.getCertID() is not needed in the ACME context anymore. This method has been marked as deprecated. In a future version of acme4j, it will be removed without replacement. If you need the certificate ID, refer to the source code to see how it is computed, and add a similar method to your own project.

Migration to Version 3.0.0

Although acme4j has made a major version bump, the migration of your code should be done in a few minutes for most of you.

  • The acme4j-utils module has been removed, and its classes moved into acme4j-client module. If you have used it before, just remove the dependency. If your project has a module-info.java file, remember to remove the requires org.shredzone.acme4j.utils line there as well.
  • All @Nullable return values have been removed where possible. Returned collections may now be empty, but are never null. Most of the other return values are now either Optional, or are throwing an exception if more reasonable. If your code fails to compile because the return type has changed to Optional, you could simply add .orElse(null) to emulate the old behavior. But often your code will reveal a better way to handle the former null pointer instead.
  • acme4j-client now depends on Bouncy Castle, so you might need to register it as security provider at the start of your code: java Security.addProvider(new BouncyCastleProvider());

What you might also need to know:

  • A new AcmeNotSupportedException is thrown if a feature is not supported by the server. It is a subclass of the AcmeProtocolException runtime exception.
  • Starting with acme4j v3, we will require the smallest Java SE LTS version that is still receiving premier support according to the Oracle Java SE Support Roadmap. At the time of writing, these are Java 11 and Java 17, so acme4j requires Java 11 starting from now. With the prospected release of Java 21 (LTS) in September 2023, we will move to Java 17, and so on. If you still need Java 8, you can use acme4j v2. However it won't receive updates anymore, except of security related fixes.
  • acme4j now uses the new java.net.http client. Due to limitations of the API, HTTP errors are only thrown with the error code, but the respective error message is missing. If you checked the error message in your unit tests, be prepared that they might fail now.
  • acme4j now accepts HTTP gzip compression. It is enabled by default, but if it causes problems or impedes debugging, it can be disabled in the NetworkSettings or by setting the org.shredzone.acme4j.gzip_compression system property to false.
  • All deprecated methods have been removed.

Migration to Version 2.16

  • In acme4j-smime, the EmailProcessor.smimeMessage() method is now deprecated. Use either EmailProcessor.signedMessage(), or EmailProcessor.builder() if you need custom verification configuration (e.g. an own truststore).
  • In acme4j-smime, major parts of the S/MIME message verification have been rewritten. The verification is much stricter now, and also supports secured headers in the certificate. Verification might now fail while it was successful in v2.15. Also, exception messages might have changed.

Migration to Version 2.15

  • acme4j-smime requires BouncyCastle now. The BouncyCastleProvider must also be added as security provider.
  • In acme4j-smime, the EmailProcessor constructor is private now. Use EmailProcessor.plainMessage() as drop-in replacement.

Migration to Version 2.13

  • The acme4j-smime module has switched from JavaMail to Jakarta Mail. Unfortunately, this is a breaking API change because classes like javax.mail.internet.InternetAddress have moved to respective jakarta.mail packages.

I am aware that this change is going to cause a lot of headache, especially if your project still uses JavaEE instead of JakartaEE. However, JavaEE has been discontinued by Oracle, so all projects are going to have to do this migration sooner or later. Let's just get it over with.

Migration to Version 2.10

  • acme4j now provides real module-info.java definitions. It also means that for building this project, Java 9 is the minimum requirement now.

  • In a preparation for Java 9 modules, the JSR305 null-safe annotations have been replaced by SpotBugs annotations. This should have no impact on your code, as the method signatures themselves are unchanged. However, the compiler could now complain about some null dereferences that have been undetected before. Reason is that JSR305 uses the javax.annotations package, which leads to split packages in a Java 9 modular environment.

  • When fetching the directory, acme4j now evaluates HTTP caching headers instead of just caching the directory for 1 hour. However, Let's Encrypt explicitly forbids caching, which means that a fresh copy of the directory is now fetched from the server every time it is needed. I don't like it, but it is the RFC conformous behavior. It needs to be fixed on Let's Encrypt side.

  • AcmeProvider.directory(Session, URI) is now responsible for maintaining the cache. Implementations can use Session.setDirectoryExpires(), Session.setDirectoryLastModified(), and the respective getters, for keeping track of the local directory state. AcmeProvider.directory(Session, URI) may now return null, to indicate that the remote directory was unchanged and the local copy is still valid. It's not permitted to return null if Session.hasDirectory() returns false, though! If your AcmeProvider is derived from AbstractAcmeProvider, and you haven't overridden the directory() method, no migration is necessary.

Migration to Version 2.9

  • In the ACME STAR draft 09, the term "recurring" has been changed to "auto-renewal". To reflect this change, all STAR related methods in the acme4j API have been renamed as well. If you are using the STAR extension, you are going to get a number of compile errors, but you will always find a corresponding new method. No functionality has been removed. I decided to do a hard API change because acme4j's STAR support is still experimental.

Migration to Version 2.8

  • Challenges can now be found by their class type instead of a type string, which makes finding a challenge type safe. I recommend to migrate your code to this new way. The classic way is not deprecated and will not be removed though. Example:
Http01Challenge challenge = auth.findChallenge(Http01Challenge.TYPE);   // old style: by name
Http01Challenge challenge = auth.findChallenge(Http01Challenge.class);  // new style: by type
  • Login.bindChallenge() was documented, but missing. It is available now. If you used a custom solution to bind challenges, you can now use the official way.

Migration to Version 2.7

  • Note that acme4j has an Automatic-Module-Name set in the acme-client and acme-utils modules now. If you have added acme4j to your Java 9+ module dependencies, you'll need to fix your dependency declaration to org.shredzone.acme4j (acme-client) and org.shredzone.acme4j.utils (acme-utils).

  • There are no breaking API changes in this version, except of the removal of CertificateUtils.createTlsAlpn01Certificate(KeyPair, String, byte[]) which has been marked as deprecated in v2.6.

  • The ACME draft has been finalized and is now called RFC 8555. For this reason, the acme4j API is now stable. There won't be breaking changes to the public API in the future, unless absolutely necessary.

Migration to Version 2.6

  • If you use the tls-alpn-01 challenge and CertificateUtils.createTlsAlpn01Certificate() for generating its test certificate, you need to pass the domain name as an Identifier object instead of a String now. You can use Identifier.dns(subject) for conversion. You can also use Authorization.getIdentifier() to get the Identifier object immediately.

Migration to Version 2.5

  • The GET compatibility mode has been removed. It also means that the postasget=false parameter is ignored from now on. If you need it to connect to your ACME server, do not update to this version until your ACME server has been fixed to support ACME draft 15.


acme4j before version 2.5 will not work with providers like Let's Encrypt any more!

Migration to Version 2.4

  • There was a major change in ACME draft 15. If you use acme4j in a common way, it will transparently take care of everything in the background, so you won't even notice the change.

However, if you connect to a different ACME server than Boulder (Let's Encrypt) or Pebble, you may now get strange errors from the server if it does not support the POST-as-GET requests of draft 15 yet. In that case, you can add a postasget=false parameter to the ACME server URI (e. g. "https://localhost:15000/dir?postasget=false"). Note that this is only a temporary workaround. It will be removed in a future version. Ask the server's CA to add support for ACME draft 15.

  • The AcmeProvider.connect() method now gets the ACME server URI as parameter. It allows to add query parameters to the server URI that change the behavior of the resulting connection. If you have implemented your own AcmeProvider, just change the method's signature to Connection connect(URI serverUri), and ignore the parameter value.

Migration to Version 2.3

  • Authorization.getDomain(), Order.getDomains() and Problem.getDomain() are deprecated now, and will be removed in version 2.4. If you use these methods, use getIdentifier() (or getIdentifiers()) to get an Identifier object, then invoke Identifier.getDomain() to get the domain name.

Migration to Version 2.2

  • No migration steps are necessary.

Migration to Version 2.1

  • This version adds JSR 305 annotations. If you use a null-safe language like Kotlin, or tools like SpotBugs, your code may fail to compile because of detected possible null pointer dereferences and unclosed streams. These are potential bugs that need to be resolved.

  • In acme4j's JSON class, all as...() getters now expect a value to be present. For optional values, use JSON.Value.optional() or JSON.Value.map(). This class is rarely used outside of acme4j itself, so you usually won't need to change anything.

Migration to Version 2.0

acme4j 2.0 fully supports the ACMEv2 protocol. Sadly, the ACMEv2 protocol is a major change.

There is no easy recipe to migrate your code to acme4j 2.0. I recommend to have a look at the example, and read this documentation. Altogether, it shouldn't be too much work to update your code, though.