putty-source/utils/cmdline_get_passwd_input_state_new.c

/*
 * A preinitialised cmdline_get_passwd_input_state which makes it easy
 * to assign by structure copy.
 */

#include "putty.h"

const cmdline_get_passwd_input_state cmdline_get_passwd_input_state_new =
    CMDLINE_GET_PASSWD_INPUT_STATE_INIT;
Fix command-line password handling in Restart Session. When the user provides a password on the PuTTY command line, via -pw or -pwfile, the flag 'tried_once' inside cmdline_get_passwd_input() is intended to arrange that we only try sending that password once, and after we've sent it, we don't try again. But this plays badly with the 'Restart Session' operation. If the connection is lost and then restarted at user request, we _do_ want to send that password again! So this commit moves that static variable out into a small state structure held by the client of cmdline_get_passwd_input. Each client can decide how to manage that state itself. Clients that support 'Restart Session' - i.e. just GUI PuTTY itself - will initialise the state at the same time as instantiating the backend, so that every time the session is restarted, we return to (correctly) believing that we _haven't_ yet tried the password provided on the command line. But clients that don't support 'Restart Session' - i.e. Plink and file transfer tools - can do the same thing that cmdline.c was doing before: just keep the state in a static variable. This also means that the GUI login tools will now retain the command-line password in memory, whereas previously they'd have wiped it out once it was used. But the other tools will still wipe and free the password, because I've also added a 'bool restartable' flag to cmdline_get_passwd_input to let it know when it _is_ allowed to do that. In the GUI tools, I don't see any way to get round that, because if the session is restarted you _have_ to still have the password to use again. (And you can't infer that that will never happen from the CONF_close_on_exit setting, because that too could be changed in mid-session.) On the other hand, I think it's not all that worrying, because the use of either -pw or -pwfile means that a persistent copy of your password is already stored somewhere, so another one isn't too big a stretch. (Due to the change of -pw policy in 0.77, the effect of this bug was that an attempt to reconnect in a session set up this way would lead to "Configured password was not accepted". In 0.76, the failure mode was different: PuTTY would interactively prompt for the password, having wiped it out of memory after it was used the first time round.) 2022-05-18 12:04:56 +00:00			`/*`
			`* A preinitialised cmdline_get_passwd_input_state which makes it easy`
			`* to assign by structure copy.`
			`*/`

			`#include "putty.h"`

			`const cmdline_get_passwd_input_state cmdline_get_passwd_input_state_new =`
			`CMDLINE_GET_PASSWD_INPUT_STATE_INIT;`