AC_DEFUN([TCLTLS_SSL_OPENSSL], [
	openssldir=''
	AC_ARG_WITH([ssl-dir],
		AS_HELP_STRING(
			[--with-ssl-dir=<dir>],
			[deprecated, use --with-openssl-dir -- currently has the same meaning]
		), [
			openssldir="$withval"
		]
	)
	AC_ARG_WITH([openssl-dir],
		AS_HELP_STRING(
			[--with-openssl-dir=<dir>],
			[path to root directory of OpenSSL or LibreSSL installation]
		), [
			openssldir="$withval"
		]
	)

	if test -n "$openssldir"; then
			if test -e "$withval/libssl.$SHOBJEXT"; then
				TCLTLS_SSL_LIBS="-L$withval -lssl -lcrypto"
				withval="`AS_DIRNAME(["$withval"])`"
			else
				TCLTLS_SSL_LIBS="-L$withval/lib -lssl -lcrypto"
			fi
			TCLTLS_SSL_CFLAGS="-I$withval/include"
			TCLTLS_SSL_CPPFLAGS="-I$withval/include"
		if test -e "$openssldir/libssl.$SHOBJEXT"; then
			TCLTLS_SSL_LIBS="-L$openssldir -lssl -lcrypto"
			openssldir="`AS_DIRNAME(["$openssldir"])`"
		else
			TCLTLS_SSL_LIBS="-L$openssldir/lib -lssl -lcrypto"
		fi
		TCLTLS_SSL_CFLAGS="-I$openssldir/include"
		TCLTLS_SSL_CPPFLAGS="-I$openssldir/include"
		]
	)
	fi

	dnl Use pkg-config to find the libraries
	AC_ARG_VAR([TCLTLS_SSL_LIBS], [libraries to pass to the linker for OpenSSL or LibreSSL])
	AC_ARG_VAR([TCLTLS_SSL_CFLAGS], [C compiler flags for OpenSSL or LibreSSL])
	AC_ARG_VAR([TCLTLS_SSL_CPPFLAGS], [C preprocessor flags for OpenSSL or LibreSSL])
	if test -z "$TCLTLS_SSL_LIBS"; then
		TCLTLS_SSL_LIBS="`"${PKGCONFIG}" openssl --libs`" || AC_MSG_ERROR([Unable to get OpenSSL Configuration])