On Thu, 4 Dec 2025 11:31:46 GMT, Nick Hall <[email protected]> wrote: >> _Purpose_ >> >> This PR allows Linux based applications using JAAS to acquire Kerberos TGTs >> natively using the local system's Kerberos libraries/configuration, building >> on existing support on Windows/MacOSX. >> >> _Rationale_ >> >> Currently the (pure java) JAAS codebase only supports file-based credential >> caches (ccaches). There are many other useful types of ccache accessible >> via the local system libraries; this change allows credentials to be >> acquired natively using those libraries, and thus adds support for all other >> ccache types supported by the local system (e.g. KCM, in-memory and kernel >> types), This support already exists on MacOSX and Windows. >> >> The code change here largely uses the MacOSX code, edited for Linux with >> associated build system changes. It also adds an appropriate jtreg test >> which uses some native test helper code to manufacture an in-memory cache, >> and then uses the new code to acquire these credentials natively. This has >> been tested on Linux/Mac and the jtreg test passes on each (I couldn't see >> any existing tests on MacOSX for this feature). >> >> Additionally this PR fixes a bug that's existed for a while (see L585-588 in >> `nativeccache.c`) - without this code, this is a 100% reproducible segfault >> on Linux (it's unclear why this hasn't affected the Mac JVMs up to now, >> probably just no calling code that provides an empty list of addresses). It >> also fixes a (non problem) typo in the variable name in a function prototype. >> >> _Implementation Detail_ >> >> Note that there were multiple possible ways of doing this: >> >> 1) Duplicate the MacOSX `nativeccache.c`, edit lightly for Linux and build a >> new library on Linux only (`liblinuxkrb5`), leaving MacOSX largely >> unchanged, but at the expense of this code duplication. >> >> 2) Create a new shared library used on both platforms with conditional >> compilation to manage the differences. This necessitates a library name >> change on MacOSX and potentially knock-on packaging changes on that >> platform, which seemed a potentially expensive side-effect. >> >> 3) Create a shared `nativeccache.c` (using `EXTRA_SRC` in the build) and >> build separate MacOSX/Linux libraries. This allows the MacOSX library name >> to remain unchanged, and only adds a new library in Linux. >> >> I tried all three options; 3 seemed to be the best compromise all around, >> although is one of the options that effectively introduces a "no-op" change >> on MacOSX as a result. Hopefully the additional jtreg test is sufficient to >> compensat... > > Nick Hall has updated the pull request incrementally with one additional > commit since the last revision: > > Update the devkit build scripts to allow the devkit to include the > required packages for KRB5 (libkrb and libcom_err). > > This was run on RHEL8, building for OL6, which required adding isl to > allow the latest gcc to build (this has been required for some time I > think). > > It also fixes one missing `--prefix` option which was causing things to > not be correctly installed in the sysroot.
Hi Nick, Thank you for the extra work on updating the devkit. After thinking it through, it’s probably not ideal to continue with the current JNI-based approach. Newer releases encourage using FFM for native interaction, and the JNI path adds extra build-time dependencies. If you’re open to it, this is a good opportunity to rewrite the feature with FFM. I’ve tried parts of it and it looks feasible. ------------- PR Comment: https://git.openjdk.org/jdk/pull/28075#issuecomment-3613683504
