The UnboundID LDAP SDK for Java is a fast, powerful, user-friendly, and completely free Java library for communicating with LDAP directory servers and performing other LDAP-related processing. We have just released version 5.0.0 of the LDAP SDK, and it is available for download from GitHub and SourceForge, as well as from the Maven Central Repository. The release notes are available online at https://docs.ldap.com/ldap-sdk/docs/release-notes.html.
The most significant change in this new release is that the LDAP SDK is now available under the terms of the Apache License, Version 2.0, which is a very permissive OSI-approved open source license. Although it was already open source under the terms of the GNU GPLv2 and LGPLv2.1, the Apache License imposes fewer restrictions on how you can use the LDAP SDK. You are no longer required to offer to redistribute the source code (even if you want to use a modified version), and there’s no longer any concern about whether you need to keep the LDAP SDK jar file as a separate component. The Apache License is well respected and is often seen as more compatible and easier to use in non-open-source software than the GNU license, so we hope that this will make it easier to use in your applications, whether open source or proprietary. The LDAP SDK is still available for use under the terms of the GPLv2 and LGPLv2.1 (as well as the non-open-source UnboundID LDAP SDK Free Use License), but we recommend that new users consider using it under the Apache License.
Aside from adding the new license, we made several code changes in this release as well. They include:
- The LDAP SDK offers an LDAPConnectionDetailsJSONSpecification class that allows you to define a JSON file with all of the settings needed to create and authenticate individual LDAP connections or connection pools. We’ve updated this class so that it’s now possible to indicate that when establishing a connection that is secured with SSL or StartTLS, the LDAP SDK should automatically trust any certificates signed by an authority in the JVM’s default set of trusted issuers. This was already the default behavior if you didn’t provide your own trust store (or choose to blindly trust all certificates, which isn’t recommended for production use), but it’s now possible to use this option in conjunction with a provided trust store so that it’s possible to trust a certificate either through that trust store or through the JVM’s default set of trusted issuers.
- The KeyStoreKeyManager can be used to obtain a certificate from a key store file if one is needed during TLS negotiation. We have updated this class to provide an option to better validate that the key store can actually be used by this purpose with the settings that you provide. If you use this option and supply the alias of the certificate you wish to use, then the key manager will now verify that the alias exists in the key store, that it’s associated with a private key entry (as opposed to a trusted certificate entry, which only contains the public portion of a certificate and isn’t suitable for use if you need to present that certificate to the peer), and that all of the certificates in the chain are currently within their validity window. If you don’t specify a certificate alias, then the validation will make sure that the key store contains at least one private key entry in which all of the certificates in the chain are within their validity window.
- The TrustStoreTrustManager can be used in the course of determining whether to trust a certificate presented by a peer during TLS negotiation. We have improved performance and concurrency for this trust manager by eliminating unnecessary synchronization that forced interaction with the trust store to be single-threaded.
- We fixed an issue that could interfere with GSSAPI authentication if a JAAS login module configuration was loaded and cached by the JVM before the login attempt. In such cases, the cached configuration could be used instead of the one that was intended.
- The LDAPDebuggerRequestHandler can be used to log detailed information about LDAP requests and responses that pass through an application using the LDAP SDK’s LDAPListener framework (including the in-memory directory server and the ldap-debugger command-line tool). We fixed an issue that could cause messages to be held up in an internal buffer rather than immediately written out as soon as they’re logged. In some cases, this could significantly delay the appearance of these messages or could prevent them from being written out at all if the amount of data to be logged was never enough to fill that internal buffer.
- We added a new JSONAccessLogRequestHandler to the LDAPListener framework. This can log information about requests and responses as JSON objects, which are both human-readable and machine-parseable. While the existing AccessLogRequestHandler produces output that can be parsed programmatically to some extent, it is more optimized for human readability.
- The LDAP SDK offers debugging logging support that can be helpful in diagnosing problems whose cause may not otherwise be readily apparent. Previously, the debug messages were logged in a form that was primarily intended to be human-readable rather than machine-parseable. They are now written in a JSON format that is both human-readable and machine-parseable.
- The manage-certificates command-line tool provides a utility for interacting with certificate key and trust stores in the Java JKS format or the standard PKCS#12 format. When displaying detailed information about certificates in a key or trust store, the tool may not have been able to properly decode public key information for certificates with 384-bit elliptic curve public keys, and it also may not have been able to properly decode a subject alternative names extension that included one or more directoryName values. While it was still possible to display most of the information about the affected certificates, the updated version can now provide the full details about those elements.
- The Ping Identity Directory Server includes a collect-support-data utility that can be used to gather a variety of information from a server installation that can be very useful for troubleshooting problems, tuning performance and scalability, and better understanding the environment in which the server is running. Previously, this utility could only be invoked by logging into the system on which the server instance is running and running the command-line tool. We have now added a couple of additional mechanisms for running the utility. It can now be invoked via an administrative task (either as an individual event that is requested by a remote client or as a recurring task that runs on a regular basis) that will create the resulting support data archive in a specified location on the system (which may be a shared filesystem for easier exfiltration). It can also be invoked via an extended operation that will run the tool and stream its output and the resulting support data archive back to the client in the form of intermediate response messages. Further, although the logic for actually collecting all of this support information remains in the server, we have added the collect-support-data command-line tool to the LDAP SDK so that it is easier to invoke the tool against a remote server without needing to install the server software on the client system.
- The Ping Identity Directory Server provides a monitor backend that authorized clients can use to obtain a wealth of useful information about the state of the server, and the LDAP SDK includes support for retrieving and parsing the information in these monitor entries. We have updated the LDAP SDK’s support for the general monitor (that is, the top-level “cn=monitor” entry) to make it easier to obtain information about the cluster with which the server is associated, the location of the server instance, and a unique identifier that was generated for the server when the instance was initially configured.
- The LDAP SDK offers a Version class that provides version information for the LDAP SDK, including the version number and information about the repository (e.g., the repository URL and revision ID) from which the LDAP SDK source code was obtained. This information was previously only offered as public static final constants, but referencing these constants from third-party applications could lead to unexpected behavior thanks to a “feature” of the Java compiler that will directly imbed the values of those constants (even if they come from a separate library) in the Java bytecode that it generates. This means that if your application references these LDAP SDK version constants and you compile it against one version of the LDAP SDK, then those version constants will be placed directly into the compiled bytecode. If you upgrade the LDAP SDK version that you use without recompiling your application (e.g., by just replacing the LDAP SDK jar file with a newer version), the code referencing the LDAP SDK version would still have the old values. To address this, we have updated the Version class to provide methods for obtaining the values of all the version constants. If you use these methods to obtain the values rather than referencing the constants directly, then you will always get the correct LDAP SDK version information even if you update the LDAP SDK without recompiling your application.