hx509/kdc: Move KDC CA utility function into hx509

This is part of the program to move REST services like bx509d out of
kdc/.

kdc/test_token_validator.c

@@ -27,6 +27,37 @@ usage(int e)
     return e;
 }
 
+static const char *sysplugin_dirs[] =  {
+#ifdef _WIN32
+    "$ORIGIN",
+#else
+    "$ORIGIN/../lib/plugin/kdc",
+#endif
+#ifdef __APPLE__
+    LIBDIR "/plugin/kdc",
+#endif
+    NULL
+};
+
+static void
+load_plugins(krb5_context context)
+{
+    const char * const *dirs = sysplugin_dirs;
+#ifndef _WIN32
+    char **cfdirs;
+
+    cfdirs = krb5_config_get_strings(context, NULL, "kdc", "plugin_dir", NULL);
+    if (cfdirs)
+        dirs = (const char * const *)cfdirs;
+#endif
+
+    _krb5_load_plugins(context, "kdc", (const char **)dirs);
+
+#ifndef _WIN32
+    krb5_config_free_strings(cfdirs);
+#endif
+}
+
 int
 main(int argc, char **argv)
 {
@@ -60,6 +91,8 @@ main(int argc, char **argv)
     if ((ret = krb5_init_context(&context)))
         err(1, "Could not initialize krb5_context");
 
+    load_plugins(context);
+
     token_type = argv[0];
     token.data = argv[1];
     if (strcmp(token.data, "-") == 0) {