simon-git: putty (main): Simon Tatham

[Commits to Tartarus hosted VCS]

TL;DR:
  21c2e451 winpgnt: fix crash if deferred-decryption passphrase is wrong.

Repository:     https://git.tartarus.org/simon/putty.git
On the web:     https://git.tartarus.org/?p=simon/putty.git
Branch updated: main
Committer:      Simon Tatham <anakin at pobox.com>
Date:           2021-04-07 20:19:12

commit 21c2e451dade78bf5590af4b84a68fc608840317
web diff https://git.tartarus.org/?p=simon/putty.git;a=commitdiff;h=21c2e451dade78bf5590af4b84a68fc608840317;hp=1069ba6a01d16d9b0f5ee50e4d74cb3ff80d39c5
Author: Simon Tatham <anakin at pobox.com>
Date:   Wed Apr 7 20:15:34 2021 +0100

    winpgnt: fix crash if deferred-decryption passphrase is wrong.
    
    Thanks to Jacob for spotting this one: when we hand a passphrase back
    to pageant.c via pageant_passphrase_request_success(), if the key
    doesn't decrypt successfully, pageant.c responds by immediately
    issuing another passphrase prompt - and it does it _synchronously_, by
    calling back from within pageant_passphrase_request_success(). In this
    case, the effect is that we end up in ask_passphrase_common(), which
    starts by asserting that nonmodal_passphrase_hwnd is NULL - but it
    wasn't NULL _quite_ yet, because end_passphrase_dialog() was expecting
    to clean it up immediately after pageant_passphrase_request_success()
    returned, i.e. just too late.
    
    The heavyweight fix would be to arrange a toplevel callback to defer
    opening the new window until after the old one had been cleaned up.
    But in this case I don't think there's any need: it's enough to simply
    do the operations in end_passphrase_dialog() in the opposite order, so
    that first we destroy the old window and set nonmodal_passphrase_hwnd
    back to NULL, and _then_ we call into pageant.c which might call us
    back and open a fresh window.

 windows/winpgnt.c | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)