int MAIN(int argc, char **argv)
	{
	ENGINE *e = NULL;
	DH *dh=NULL;
	int ret=1,num=DEFBITS;
	int g=2;
	char *outfile=NULL;
	char *inrand=NULL;
	char *engine=NULL;
	BIO *out=NULL;

	apps_startup();

	if (bio_err == NULL)
		if ((bio_err=BIO_new(BIO_s_file())) != NULL)
			BIO_set_fp(bio_err,stderr,BIO_NOCLOSE|BIO_FP_TEXT);

	argv++;
	argc--;
	for (;;)
		{
		if (argc <= 0) break;
		if (strcmp(*argv,"-out") == 0)
			{
			if (--argc < 1) goto bad;
			outfile= *(++argv);
			}
		else if (strcmp(*argv,"-2") == 0)
			g=2;
	/*	else if (strcmp(*argv,"-3") == 0)
			g=3; */
		else if (strcmp(*argv,"-5") == 0)
			g=5;
		else if (strcmp(*argv,"-engine") == 0)
			{
			if (--argc < 1) goto bad;
			engine= *(++argv);
			}
		else if (strcmp(*argv,"-rand") == 0)
			{
			if (--argc < 1) goto bad;
			inrand= *(++argv);
			}
		else
			break;
		argv++;
		argc--;
		}
	if ((argc >= 1) && ((sscanf(*argv,"%d",&num) == 0) || (num < 0)))
		{
bad:
		BIO_printf(bio_err,"usage: gendh [args] [numbits]\n");
		BIO_printf(bio_err," -out file - output the key to 'file\n");
		BIO_printf(bio_err," -2        - use 2 as the generator value\n");
	/*	BIO_printf(bio_err," -3        - use 3 as the generator value\n"); */
		BIO_printf(bio_err," -5        - use 5 as the generator value\n");
		BIO_printf(bio_err," -engine e - use engine e, possibly a hardware device.\n");
		BIO_printf(bio_err," -rand file%cfile%c...\n", LIST_SEPARATOR_CHAR, LIST_SEPARATOR_CHAR);
		BIO_printf(bio_err,"           - load the file (or the files in the directory) into\n");
		BIO_printf(bio_err,"             the random number generator\n");
		goto end;
		}
		
	if (engine != NULL)
		{
		if((e = ENGINE_by_id(engine)) == NULL)
			{
			BIO_printf(bio_err,"invalid engine \"%s\"\n",
				engine);
			goto end;
			}
		if(!ENGINE_set_default(e, ENGINE_METHOD_ALL))
			{
			BIO_printf(bio_err,"can't use that engine\n");
			goto end;
			}
		BIO_printf(bio_err,"engine \"%s\" set.\n", engine);
		/* Free our "structural" reference. */
		ENGINE_free(e);
		}

	out=BIO_new(BIO_s_file());
	if (out == NULL)
		{
		ERR_print_errors(bio_err);
		goto end;
		}

	if (outfile == NULL)
		{
		BIO_set_fp(out,stdout,BIO_NOCLOSE);
#ifdef VMS
		{
		BIO *tmpbio = BIO_new(BIO_f_linebuffer());
		out = BIO_push(tmpbio, out);
		}
#endif
		}
	else
		{
		if (BIO_write_filename(out,outfile) <= 0)
			{
			perror(outfile);
			goto end;
			}
		}

	if (!app_RAND_load_file(NULL, bio_err, 1) && inrand == NULL)
		{
		BIO_printf(bio_err,"warning, not much extra random data, consider using the -rand option\n");
		}
	if (inrand != NULL)
		BIO_printf(bio_err,"%ld semi-random bytes loaded\n",
			app_RAND_load_files(inrand));

	BIO_printf(bio_err,"Generating DH parameters, %d bit long safe prime, generator %d\n",num,g);
	BIO_printf(bio_err,"This is going to take a long time\n");
	dh=DH_generate_parameters(num,g,dh_cb,bio_err);
		
	if (dh == NULL) goto end;

	app_RAND_write_file(NULL, bio_err);

	if (!PEM_write_bio_DHparams(out,dh))
		goto end;
	ret=0;
end:
	if (ret != 0)
		ERR_print_errors(bio_err);
	if (out != NULL) BIO_free_all(out);
	if (dh != NULL) DH_free(dh);
	EXIT(ret);
	}