Chapter 2. Differences from upstream OpenJDK 17

OpenJDK in Red Hat Enterprise Linux contains a number of structural changes from the upstream distribution of OpenJDK. The Microsoft Windows version of OpenJDK attempts to follow Red Hat Enterprise Linux updates as closely as possible.

The following list details the most notable Red Hat OpenJDK 17 changes:

  • FIPS support. Red Hat OpenJDK 17 automatically detects whether RHEL is in FIPS mode and automatically configures OpenJDK 17 to operate in that mode. This change does not apply to OpenJDK builds for Microsoft Windows.
  • Cryptographic policy support. Red Hat OpenJDK 17 obtains the list of enabled cryptographic algorithms and key size constraints from the RHEL system configuration. These configuration components are used by the Transport Layer Security (TLS) encryption protocol, the certificate path validation, and any signed JARs. You can set different security profiles to balance safety and compatibility. This change does not apply to OpenJDK builds for Microsoft Windows.
  • Red Hat OpenJDK on RHEL dynamically links against native libraries such as zlib for archive format support and libjpeg-turbo, libpng, and giflib for image support. RHEL also dynamically links against Harfbuzz and Freetype for font rendering and management. This change does not apply to OpenJDK builds for Microsoft Windows.
  • The src.zip file includes the source for all of the JAR libraries shipped with OpenJDK.
  • Red Hat OpenJDK on RHEL uses system-wide timezone data files as a source for timezone information.
  • Red Hat OpenJDK on RHEL uses system-wide CA certificates.
  • Red Hat OpenJDK on Microsoft Windows includes the latest available timezone data from RHEL.
  • Red Hat OpenJDK on Microsoft Windows uses the latest available CA certificate from RHEL.