Struct timing_shield::TpU8

pub struct TpU8(_);

A number type that prevents its value from being leaked to attackers through timing information.

Use this type's protect method as early as possible to prevent the value from being used in variable-time computations.

Unlike Rust's built-in number types, rust-timing-shield number types have no overflow checking, even in debug mode. In other words, they behave like Rust's Wrapping types.

Additionally, all shift distances are reduced mod the bit width of the type (e.g. some_i64 << 104 is equivalent to some_i64 << 40).

// Protect the value as early as possible to limit the risk
let protected_value = TpU8::protect(some_u8);
let other_protected_value = TpU8::protect(some_other_u8);

// Do some computation with the protected values
let x = (other_protected_value + protected_value) & 0x40;

// If needed, remove protection using `expose`
println!("{}", x.expose());

Methods

impl TpU8

fn protect(input: u8) -> Self

Hide input behind a protective abstraction to prevent the value from being used in such a way that the value could leak out via a timing side channel.

let protected = TpU32::protect(secret_u32);

// Use `protected` instead of `secret_u32` to avoid timing leaks

fn as_u16(self) -> TpU16

Casts from one number type to another, following the same conventions as Rust's as keyword.

fn as_u32(self) -> TpU32

Casts from one number type to another, following the same conventions as Rust's as keyword.

fn as_u64(self) -> TpU64

Casts from one number type to another, following the same conventions as Rust's as keyword.

fn as_i8(self) -> TpI8

Casts from one number type to another, following the same conventions as Rust's as keyword.

fn as_i16(self) -> TpI16

Casts from one number type to another, following the same conventions as Rust's as keyword.

fn as_i32(self) -> TpI32

Casts from one number type to another, following the same conventions as Rust's as keyword.

fn as_i64(self) -> TpI64

Casts from one number type to another, following the same conventions as Rust's as keyword.

fn expose(self) -> u8

Remove the timing protection and expose the raw number value. Once a value is exposed, it is the library user's responsibility to prevent timing leaks (if necessary).

Commonly, this method is used when a value is safe to make public (e.g. when an encryption algorithm outputs a ciphertext). Alternatively, this method may need to be used when providing a secret value to an interface that does not use timing-shield's types (e.g. writing a secret key to a file using a file system API).

Trait Implementations

impl Clone for TpU8

fn clone(&self) -> TpU8

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for TpU8

impl Not for TpU8

type Output = TpU8

The resulting type after applying the ! operator

fn not(self) -> TpU8

The method for the unary ! operator

impl Add<TpU8> for TpU8

type Output = TpU8

The resulting type after applying the + operator

fn add(self, other: TpU8) -> TpU8

The method for the + operator

impl Add<u8> for TpU8

type Output = TpU8

The resulting type after applying the + operator

fn add(self, other: u8) -> TpU8

The method for the + operator

impl Sub<TpU8> for TpU8

type Output = TpU8

The resulting type after applying the - operator

fn sub(self, other: TpU8) -> TpU8

The method for the - operator

impl Sub<u8> for TpU8

type Output = TpU8

The resulting type after applying the - operator

fn sub(self, other: u8) -> TpU8

The method for the - operator

impl Mul<TpU8> for TpU8

type Output = TpU8

The resulting type after applying the * operator

fn mul(self, other: TpU8) -> TpU8

The method for the * operator

impl Mul<u8> for TpU8

type Output = TpU8

The resulting type after applying the * operator

fn mul(self, other: u8) -> TpU8

The method for the * operator

impl BitAnd<TpU8> for TpU8

type Output = TpU8

The resulting type after applying the & operator

fn bitand(self, other: TpU8) -> TpU8

The method for the & operator

impl BitAnd<u8> for TpU8

type Output = TpU8

The resulting type after applying the & operator

fn bitand(self, other: u8) -> TpU8

The method for the & operator

impl BitOr<TpU8> for TpU8

type Output = TpU8

The resulting type after applying the | operator

fn bitor(self, other: TpU8) -> TpU8

The method for the | operator

impl BitOr<u8> for TpU8

type Output = TpU8

The resulting type after applying the | operator

fn bitor(self, other: u8) -> TpU8

The method for the | operator

impl BitXor<TpU8> for TpU8

type Output = TpU8

The resulting type after applying the ^ operator

fn bitxor(self, other: TpU8) -> TpU8

The method for the ^ operator

impl BitXor<u8> for TpU8

type Output = TpU8

The resulting type after applying the ^ operator

fn bitxor(self, other: u8) -> TpU8

The method for the ^ operator

impl Shl<u32> for TpU8

type Output = TpU8

The resulting type after applying the << operator

fn shl(self, other: u32) -> TpU8

The method for the << operator

impl Shr<u32> for TpU8

type Output = TpU8

The resulting type after applying the >> operator

fn shr(self, other: u32) -> TpU8

The method for the >> operator

impl AddAssign<TpU8> for TpU8

fn add_assign(&mut self, rhs: TpU8)

The method for the += operator

impl AddAssign<u8> for TpU8

fn add_assign(&mut self, rhs: u8)

The method for the += operator

impl SubAssign<TpU8> for TpU8

fn sub_assign(&mut self, rhs: TpU8)

The method for the -= operator

impl SubAssign<u8> for TpU8

fn sub_assign(&mut self, rhs: u8)

The method for the -= operator

impl MulAssign<TpU8> for TpU8

fn mul_assign(&mut self, rhs: TpU8)

The method for the *= operator

impl MulAssign<u8> for TpU8

fn mul_assign(&mut self, rhs: u8)

The method for the *= operator

impl BitAndAssign<TpU8> for TpU8

fn bitand_assign(&mut self, rhs: TpU8)

The method for the &= operator

impl BitAndAssign<u8> for TpU8

fn bitand_assign(&mut self, rhs: u8)

The method for the &= operator

impl BitOrAssign<TpU8> for TpU8

fn bitor_assign(&mut self, rhs: TpU8)

The method for the |= operator

impl BitOrAssign<u8> for TpU8

fn bitor_assign(&mut self, rhs: u8)

The method for the |= operator

impl BitXorAssign<TpU8> for TpU8

fn bitxor_assign(&mut self, rhs: TpU8)

The method for the ^= operator

impl BitXorAssign<u8> for TpU8

fn bitxor_assign(&mut self, rhs: u8)

The method for the ^= operator

impl ShlAssign<u32> for TpU8

fn shl_assign(&mut self, rhs: u32)

The method for the <<= operator

impl ShrAssign<u32> for TpU8

fn shr_assign(&mut self, rhs: u32)

The method for the >>= operator

impl TpEq<TpU8> for TpU8

fn tp_eq(&self, other: &TpU8) -> TpBool

Compare self with other for equality without leaking the result. Important: if either input is not a timing-protected type, this operation might leak the value of that type. To prevent timing leaks, protect values before performing any operations on them.

fn tp_not_eq(&self, other: &TpU8) -> TpBool

Compare self with other for inequality without leaking the result. Important: if either input is not a timing-protected type, this operation might leak the value of that type. To prevent timing leaks, protect values before performing any operations on them.

impl TpEq<u8> for TpU8

fn tp_eq(&self, other: &u8) -> TpBool

Compare self with other for equality without leaking the result. Important: if either input is not a timing-protected type, this operation might leak the value of that type. To prevent timing leaks, protect values before performing any operations on them.

fn tp_not_eq(&self, other: &u8) -> TpBool

Compare self with other for inequality without leaking the result. Important: if either input is not a timing-protected type, this operation might leak the value of that type. To prevent timing leaks, protect values before performing any operations on them.

impl TpOrd<TpU8> for TpU8

fn tp_lt(&self, other: &TpU8) -> TpBool

Compute self < other without leaking the result. Important: if either input is not a timing-protected type, this operation might leak the value of that type. To prevent timing leaks, protect values before performing any operations on them.

fn tp_gt(&self, other: &TpU8) -> TpBool

Compute self > other without leaking the result. Important: if either input is not a timing-protected type, this operation might leak the value of that type. To prevent timing leaks, protect values before performing any operations on them.

fn tp_lt_eq(&self, other: &TpU8) -> TpBool

Compute self <= other without leaking the result. Important: if either input is not a timing-protected type, this operation might leak the value of that type. To prevent timing leaks, protect values before performing any operations on them.

fn tp_gt_eq(&self, other: &TpU8) -> TpBool

Compute self >= other without leaking the result. Important: if either input is not a timing-protected type, this operation might leak the value of that type. To prevent timing leaks, protect values before performing any operations on them.

impl TpOrd<u8> for TpU8

fn tp_lt(&self, other: &u8) -> TpBool

Compute self < other without leaking the result. Important: if either input is not a timing-protected type, this operation might leak the value of that type. To prevent timing leaks, protect values before performing any operations on them.

fn tp_gt(&self, other: &u8) -> TpBool

Compute self > other without leaking the result. Important: if either input is not a timing-protected type, this operation might leak the value of that type. To prevent timing leaks, protect values before performing any operations on them.

fn tp_lt_eq(&self, other: &u8) -> TpBool

Compute self <= other without leaking the result. Important: if either input is not a timing-protected type, this operation might leak the value of that type. To prevent timing leaks, protect values before performing any operations on them.

fn tp_gt_eq(&self, other: &u8) -> TpBool

Compute self >= other without leaking the result. Important: if either input is not a timing-protected type, this operation might leak the value of that type. To prevent timing leaks, protect values before performing any operations on them.

impl TpCondSwap for TpU8

fn tp_cond_swap(condition: TpBool, a: &mut TpU8, b: &mut TpU8)

Swap a and b if and only if condition is true.