adding JWT enablement to C samples

[shreeya1510]

No description provided.

[ibmmqmet]

While the basic function looks to be OK, there's a bunch of things that ought to be sorted out:

• CRLF chars - when I pulled down the changes all the lines had ^M characters at the end. DOS format. Ought to check the real format for consistency. Maybe your git config core.autocrlf needs checking. Makes the files look messy on Linux.
• Your README and Makefile assumes MacOS. Homebrew is a MacOS-only thing. You need to check everything on Linux too.
  • Maybe have multiple default definitions in the Makefile based on the OS
• Using ifeq does not work on the standard AIX make. On that platform, you have to use the GNU version of make
• What's the situation on Windows? The README at minimum ought to say that the JWT example code can't be built there
• Using userid/password to authenticate to the keycloak server is deprecated. It should be using ClientID and ClientSecret. Which has a slightly different endpoint syntax.
• Copyright dates on modified files should still have the original date as well as the most recently changed date. So "(c) 2024,2025"
• The code would not build on Linux because the Makefile pulled in MQ's shipped copy of the curl library.
  • Moving the JWT_LDFLAGS before the MQLIB seemed to sort that out
• Some of the C parts need layout cleanup. For example there's at least one unindented block inside an if. And for consistency, you need spaces in } else {.
• Note that the keystore cannot be the standard MQ kdb format - has to be something that OpenSSL (used from curl) can work with. So maybe needs instructions on creating that.
  • You might be able to use the MQ-provided curl to access kdb files with suitable changes to the build or environment, but that's probably not a good idea