;;
		bits=*)
			bits="`echo "${arg}" | cut -f 2 -d =`"
			;;
	esac
done

openssl_dhparam1() {
	if openssl dhparam -C "$@" | sed	\
	    -e 's/^\(static \)*DH \*get_dh[0-9]*/static DH *get_dhParams/'	\
	    -e '/^-----BEGIN DH PARAMETERS-----$/,/^-----END DH PARAMETERS-----$/ d;/^#/ d'
	then
		return 0
	fi

	return 1
}

# OpenSSL 3.0 openssl-dhparam has no "-C" option, so we emulate it here
openssl_dhparam3() {
	cat << \_EOF_
#include <openssl/dh.h>
#include <openssl/bn.h>
static DH *get_dhParams(void) {
	static unsigned char dhp[] = {
_EOF_

	openssl dhparam -text "$@" | \
	    sed -E -e '/^---/,/^---/d' \
		-e '/(DH|prime|generator|P|G|recommended)/d' \
		-e 's/([0-9a-h]{2})(:|$$)/0x\1, /g'

	cat << \_EOF_
	};
	static unsigned char dhg[] = {
		0x02,
	};

	DH *dh = DH_new();;
	BIGNUM *p, *g;

	if (dh == NULL) {
		return NULL;
	}

	p = BN_bin2bn(dhp, sizeof (dhp), NULL);
	g = BN_bin2bn(dhg, sizeof (dhg), NULL);

	if (p == NULL || g == NULL || !DH_set0_pqg(dh, p, NULL, g)) {
		DH_free(dh);
		BN_free(p);
		BN_free(g);
		return(NULL);
	}
	return dh;
}
_EOF_

	return 0
}

gen_dh_params_openssl() {
	openssl_dhparam3 "${bits}" < /dev/null || return 1
	return 0
}

gen_dh_params_remote() {
	url="https://2ton.com.au/dhparam/${bits}"

	r_input="`curl -sS "${url}"`" || \
		r_input="`wget -O - -o /dev/null "${url}"`" || return 1

	if r_output="`echo "${r_input}" | openssl_dhparam1`"; then
		echo "${r_output}"

		return 0
	fi

	return 1
}

gen_dh_params_fallback() {
	cat << \_EOF_
#include <openssl/dh.h>
#include <openssl/bn.h>
DH *get_dhParams(void) {
	static unsigned char dhp[] = {
_EOF_
	case "${bits}" in
		2048)
			cat << \_EOF_
		0xC1,0x51,0x58,0x69,0xFB,0xE8,0x6C,0x47,0x2B,0x86,0x61,0x4F,

echo "*****************************" >&2
echo "** Generating DH Primes.   **" >&2
echo "** This will take a while. **" >&2
echo "*****************************" >&2
echo "Use OpenSSL" >&2
gen_dh_params_openssl && exit 0
#echo "Use Remote" >&2
#gen_dh_params_remote && exit 0
echo "Use fallback" >&2
gen_dh_params_fallback && exit 0

echo "Unable to generate parameters for DH of ${bits} bits" >&2

exit 1

	OPTBYTE("-key", key, key_len);
	OPTSTR("-keyfile", keyfile);
	OPTSTR("-model", model);
	OPTOBJ("-password", password);
	OPTBOOL("-post_handshake", post_handshake);
	OPTBOOL("-request", request);
	OPTBOOL("-require", require);
	OPTINT("-securitylevel", level);
	OPTBOOL("-server", server);
	OPTSTR("-servername", servername);
	OPTSTR("-session_id", session_id);
	OPTBOOL("-ssl2", ssl2);
	OPTBOOL("-ssl3", ssl3);
	OPTBOOL("-tls1", tls1);
	OPTBOOL("-tls1.1", tls1_1);
	OPTBOOL("-tls1.2", tls1_2);
	OPTBOOL("-tls1.3", tls1_3);
	OPTOBJ("-validatecommand", vcmd);
	OPTOBJ("-vcmd", vcmd);

	OPTBAD("option", "-alpn, -cadir, -cafile, -cert, -certfile, -cipher, -ciphersuites, -command, -dhparams, -key, -keyfile, -model, -password, -post_handshake, -request, -require, -securitylevel, -server, -servername, -session_id, -ssl2, -ssl3, -tls1, -tls1.1, -tls1.2, -tls1.3, or -validatecommand");

	return TCL_ERROR;
    }
    if (request)		verify |= SSL_VERIFY_CLIENT_ONCE | SSL_VERIFY_PEER;
    if (request && require)	verify |= SSL_VERIFY_FAIL_IF_NO_PEER_CERT;
    if (request && post_handshake)	verify |= SSL_VERIFY_POST_HANDSHAKE;
    if (verify == 0)		verify = SSL_VERIFY_NONE;