options: Complete the transition to numeric toggles (`#if') For the sake of review, this commit alters only the code; the affiliated comments within the source files also need to be updated, but doing so now would obscure the operational changes that have been made here. * All on/off options have been switched to the numeric `#if' variant; that is the only way to make this `default_options.h.in' thing work in a reasonable manner. * There is now some very minor compile-time checking of the user's choice of options. * NO_FAST_EXPTMOD doesn't seem to be used, so it has been removed. * ENABLE_USER_ALGO_LIST was supposed to be renamed DROPBEAR_USER_ALGO_LIST, and this commit completes that work. * DROPBEAR_FUZZ seems to be a relatively new, as-yet undocumented option, which was added by the following commit: commit 6e0b539e9ca0b5628c6c5a3d118ad6a2e79e8039 Author: Matt Johnston <[email protected]> Date: Tue May 23 22:29:21 2017 +0800 split out checkpubkey_line() separately It has now been added to `sysoptions.h' and defined as `0' by default. * The configuration option `DROPBEAR_PASSWORD_ENV' is no longer listed in `default_options.h.in'; it is no longer meant to be set by the user, and is instead left to be defined in `sysoptions.h' (where it was already being defined) as merely the name of the environment variable in question: DROPBEAR_PASSWORD To enable or disable use of that environment variable, the user must now toggle `DROPBEAR_USE_DROPBEAR_PASSWORD'. * The sFTP support is now toggled by setting `DROPBEAR_SFTPSERVER', and the path of the sFTP server program is set independently through the usual SFTPSERVER_PATH.

--- a/svr-runopts.c	Wed Feb 14 23:09:40 2018 +0800
+++ b/svr-runopts.c	Thu Jul 20 19:38:26 2017 +0000
@@ -64,7 +64,7 @@
 #else
 					"-E		Log to stderr rather than syslog\n"
 #endif
-#ifdef DO_MOTD
+#if DO_MOTD
 					"-m		Don't display the motd on login\n"
 #endif
 					"-w		Disallow root logins\n"
@@ -88,7 +88,7 @@
 					"		(default port is %s if none specified)\n"
 					"-P PidFile	Create pid file PidFile\n"
 					"		(default %s)\n"
-#ifdef INETD_MODE
+#if INETD_MODE
 					"-i		Start for inetd\n"
 #endif
 					"-W <receive_window_buffer> (default %d, larger may be faster, max 1MB)\n"
@@ -156,7 +156,7 @@
 	opts.ipv4 = 1;
 	opts.ipv6 = 1;
 	*/
-#ifdef DO_MOTD
+#if DO_MOTD
 	svr_opts.domotd = 1;
 #endif
 #ifndef DISABLE_SYSLOG
@@ -210,7 +210,7 @@
 					opts.listen_fwd_all = 1;
 					break;
 #endif
-#ifdef INETD_MODE
+#if INETD_MODE
 				case 'i':
 					svr_opts.inetdmode = 1;
 					break;
@@ -221,7 +221,7 @@
 				case 'P':
 					next = &svr_opts.pidfile;
 					break;
-#ifdef DO_MOTD
+#if DO_MOTD
 				/* motd is displayed by default, -m turns it off */
 				case 'm':
 					svr_opts.domotd = 0;