Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Improve Multiply() macro for additional safety #223

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
Open

Improve Multiply() macro for additional safety #223

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
12 changes: 6 additions & 6 deletions aes.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -326,12 +326,12 @@ static uint8_t Multiply(uint8_t x, uint8_t y)
((y>>4 & 1) * xtime(xtime(xtime(xtime(x)))))); /* this last call to xtime() can be omitted */
}
#else
#define Multiply(x, y) \
( ((y & 1) * x) ^ \
((y>>1 & 1) * xtime(x)) ^ \
((y>>2 & 1) * xtime(xtime(x))) ^ \
((y>>3 & 1) * xtime(xtime(xtime(x)))) ^ \
((y>>4 & 1) * xtime(xtime(xtime(xtime(x)))))) \
#define Multiply(x, y) \
( (((y) & 1) * (x)) ^ \
(((y)>>1 & 1) * xtime((x))) ^ \
(((y)>>2 & 1) * xtime(xtime((x)))) ^ \
(((y)>>3 & 1) * xtime(xtime(xtime((x))))) ^ \
(((y)>>4 & 1) * xtime(xtime(xtime(xtime((x))))))) \

#endif

Expand Down