Struct BigInt 

pub struct BigInt {
    pub limbs: Vec<u64>,
}

A big unsigned integer stored as little-endian 64-bit limbs.

Fields

limbs: Vec<u64>

Limbs in little-endian order (limbs[0] is least significant).

Implementations

impl BigInt

pub fn zero() -> Self

Zero value.

pub fn from_u64(v: u64) -> Self

From a single u64.

pub fn from_be_bytes(bytes: &[u8]) -> Self

From big-endian bytes (as in RSA wire format).

pub fn to_be_bytes(&self, min_len: usize) -> Vec<u8>

Convert to big-endian bytes, padded to at least min_len bytes.

pub fn bit_len(&self) -> usize

Number of significant bits.

pub fn bit(&self, i: usize) -> bool

Test whether bit i is set.

pub fn set_bit(&mut self, i: usize)

Set bit i.

pub fn is_zero(&self) -> bool

Is this number zero?

pub fn is_even(&self) -> bool

Is this number even?

pub fn is_odd(&self) -> bool

Is this number odd?

pub fn byte_len(&self) -> usize

Byte length of the modulus (for RSA octet-string conversion).

pub fn random(bits: usize, rng: &mut dyn FnMut(&mut [u8])) -> Self

Generate a random BigInt with exactly bits bits using the provided RNG callback.

pub fn random_odd(bits: usize, rng: &mut dyn FnMut(&mut [u8])) -> Self

Generate a random odd BigInt with exactly bits bits.

impl BigInt

pub fn cmp_to(&self, other: &Self) -> Ordering

Compare self to other as unsigned big integers. Used by the Ord / PartialOrd impls and exposed publicly so callers can perform a comparison without allocating an Ordering via the trait machinery in tight loops.

impl BigInt

pub fn add(&self, other: &BigInt) -> BigInt

self + other

pub fn add_u64(&self, v: u64) -> BigInt

self + small (u64)

impl BigInt

pub fn sub(&self, other: &BigInt) -> BigInt

self - other (panics if result would be negative)

pub fn sub_one(&self) -> BigInt

self - 1

impl BigInt

pub fn mul(&self, other: &BigInt) -> BigInt

self * other (schoolbook O(n^2))

impl BigInt

pub fn div_rem(&self, divisor: &BigInt) -> (BigInt, BigInt)

(quotient, remainder) = self / divisor Uses long division.

pub fn shl(&self, bits: usize) -> BigInt

Left shift by bits bit positions.

pub fn shr(&self, bits: usize) -> BigInt

Right shift by bits bit positions.

pub fn rem(&self, modulus: &BigInt) -> BigInt

self mod other

impl BigInt

pub fn mod_exp(&self, exp: &BigInt, modulus: &BigInt) -> BigInt

Modular exponentiation: self^exp mod modulus. Uses Montgomery multiplication internally for constant-time operation.

pub fn mod_inv(&self, modulus: &BigInt) -> Option<BigInt>

Modular inverse: self^{-1} mod modulus, using extended GCD. Returns None if gcd(self, modulus) != 1.

impl BigInt

pub fn is_probably_prime( &self, rounds: usize, rng: &mut dyn FnMut(&mut [u8]), ) -> bool

Miller-Rabin primality test with rounds iterations. Uses the provided RNG to generate random witnesses.

pub fn random_prime(bits: usize, rng: &mut dyn FnMut(&mut [u8])) -> BigInt

Generate a random probable prime of bits bits.

Trait Implementations

impl Clone for BigInt

fn clone(&self) -> BigInt

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for BigInt

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Ord for BigInt

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for BigInt

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for BigInt

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Eq for BigInt