[−][src]Trait subtle::ConditionallySelectable
A type which can be conditionally selected in constant time.
This trait also provides generic implementations of conditional assignment and conditional swaps.
Required methods
fn conditional_select(a: &Self, b: &Self, choice: Choice) -> Self
Select a or b according to choice.
Returns
aifchoice == Choice(0);bifchoice == Choice(1).
This function should execute in constant time.
Example
use subtle::ConditionallySelectable; let x: u8 = 13; let y: u8 = 42; let z = u8::conditional_select(&x, &y, 0.into()); assert_eq!(z, x); let z = u8::conditional_select(&x, &y, 1.into()); assert_eq!(z, y);
Provided methods
fn conditional_assign(&mut self, other: &Self, choice: Choice)
Conditionally assign other to self, according to choice.
This function should execute in constant time.
Example
use subtle::ConditionallySelectable; let mut x: u8 = 13; let mut y: u8 = 42; x.conditional_assign(&y, 0.into()); assert_eq!(x, 13); x.conditional_assign(&y, 1.into()); assert_eq!(x, 42);
fn conditional_swap(a: &mut Self, b: &mut Self, choice: Choice)
Conditionally swap self and other if choice == 1; otherwise,
reassign both unto themselves.
This function should execute in constant time.
Example
use subtle::ConditionallySelectable; let mut x: u8 = 13; let mut y: u8 = 42; u8::conditional_swap(&mut x, &mut y, 0.into()); assert_eq!(x, 13); assert_eq!(y, 42); u8::conditional_swap(&mut x, &mut y, 1.into()); assert_eq!(x, 42); assert_eq!(y, 13);