simon-git: putty (master): Simon Tatham

Commits to Tartarus hosted VCS tartarus-commits at lists.tartarus.org
Sun Jan 13 21:55:02 GMT 2019


TL;DR:
  c9f673ac mpint_rshift_safe: stop using variable bit shifts.

Repository:     https://git.tartarus.org/simon/putty.git
On the web:     https://git.tartarus.org/?p=simon/putty.git
Branch updated: master
Committer:      Simon Tatham <anakin at pobox.com>
Date:           2019-01-13 21:55:02

commit c9f673ac12f867e9365350d6e426ec39e6718210
web diff https://git.tartarus.org/?p=simon/putty.git;a=commitdiff;h=c9f673ac12f867e9365350d6e426ec39e6718210;hp=ced0f1911830eceae26c737e93b44136828f2f13
Author: Simon Tatham <anakin at pobox.com>
Date:   Sun Jan 13 21:50:15 2019 +0000

    mpint_rshift_safe: stop using variable bit shifts.
    
    I've decided not to trust register-controlled shift operations to be
    time-constant after all. They're surely fine on nice fast machines
    where everything simple takes one cycle, but stranger machines,
    perhaps not. In which case, I should avoid using them in the mpint
    shift operation that's supposed not to reveal the shift count.

 mpint.c | 30 ++++++++++++------------------
 1 file changed, 12 insertions(+), 18 deletions(-)



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