Using the test_import_export_context() Function

GSS-API allows you to export and import contexts. These activities enable you to share a context between different processes in a multiprocess program. sign_server() contains a proof-of-concept function, test_import_export_context(), that illustrates how exporting and importing contexts works. test_import_export_context() does not pass a context between processes. Instead, test_import_export_context() displays the amount of time to export and then import a context. Although an artificial function, test_import_export_context() does indicate how to use the GSS-API importing and exporting functions. test_import_export_context() also shows how to use timestamps with regard to manipulating contexts.

The source code for test_import_export_context() is shown in the following example.

int test_import_export_context(context)
        gss_ctx_id_t *context;
{
        OM_uint32       min_stat, maj_stat;
        gss_buffer_desc context_token, copied_token;
        struct timeval tm1, tm2;

        /*
         * Attempt to save and then restore the context.
         */
        gettimeofday(&tm1, (struct timezone *)0);
        maj_stat = gss_export_sec_context(&min_stat, context, &context_token);
        if (maj_stat != GSS_S_COMPLETE) {
                display_status("exporting context", maj_stat, min_stat);
                return 1;
        }
        gettimeofday(&tm2, (struct timezone *)0);
        if (verbose && log)
                fprintf(log, "Exported context: %d bytes, %7.4f seconds\n",
                        context_token.length, timeval_subtract(&tm2, &tm1));
        copied_token.length = context_token.length;
        copied_token.value = malloc(context_token.length);
        if (copied_token.value == 0) {
            fprintf(log, "Couldn't allocate memory to copy context token.\n");
            return 1;
        }
        memcpy(copied_token.value, context_token.value, copied_token.length);
        maj_stat = gss_import_sec_context(&min_stat, &copied_token, context);
        if (maj_stat != GSS_S_COMPLETE) {
                display_status("importing context", maj_stat, min_stat);
                return 1;
        }
        free(copied_token.value);
        gettimeofday(&tm1, (struct timezone *)0);
        if (verbose && log)
                fprintf(log, "Importing context: %7.4f seconds\n",
                        timeval_subtract(&tm1, &tm2));
        (void) gss_release_buffer(&min_stat, &context_token);
        return 0;
}