pub trait ConstantTimeGreater {
fn ct_gt(&self, other: &Self) -> Choice;
}
Expand description
A type which can be compared in some manner and be determined to be greater
than another of the same type.
Determine whether self > other.
The bitwise-NOT of the return value of this function should be usable to
determine if self <= other.
This function should execute in constant time.
A Choice with a set bit if self > other, and with no set bits
otherwise.
use subtle_ng::ConstantTimeGreater;
let x: u8 = 13;
let y: u8 = 42;
let x_gt_y = x.ct_gt(&y);
assert_eq!(x_gt_y.unwrap_u8(), 0);
let y_gt_x = y.ct_gt(&x);
assert_eq!(y_gt_x.unwrap_u8(), 1);
let x_gt_x = x.ct_gt(&x);
assert_eq!(x_gt_x.unwrap_u8(), 0);
Returns Choice::from(1) iff x > y, and Choice::from(0) iff x <= y.
This algoritm would also work for signed integers if we first
flip the top bit, e.g. let x: u8 = x ^ 0x80, etc.
Returns Choice::from(1) iff x > y, and Choice::from(0) iff x <= y.
This algoritm would also work for signed integers if we first
flip the top bit, e.g. let x: u8 = x ^ 0x80, etc.
Returns Choice::from(1) iff x > y, and Choice::from(0) iff x <= y.
This algoritm would also work for signed integers if we first
flip the top bit, e.g. let x: u8 = x ^ 0x80, etc.
Returns Choice::from(1) iff x > y, and Choice::from(0) iff x <= y.
This algoritm would also work for signed integers if we first
flip the top bit, e.g. let x: u8 = x ^ 0x80, etc.
Returns Choice::from(1) iff x > y, and Choice::from(0) iff x <= y.
This algoritm would also work for signed integers if we first
flip the top bit, e.g. let x: u8 = x ^ 0x80, etc.