Struct openssl::bn::BigNum

pub struct BigNum(_);

A signed arbitrary-precision integer.

BigNum provides wrappers around OpenSSL's checked arithmetic functions. Additionally, it implements the standard operators (std::ops), which perform unchecked arithmetic, unwrapping the returned Result of the checked operations.

Methods

impl BigNum

pub fn new() -> Result<BigNum, SslError>

Creates a new BigNum with the value 0.

pub fn new_from(n: u64) -> Result<BigNum, SslError>

Creates a new BigNum with the given value.

pub fn from_dec_str(s: &str) -> Result<BigNum, SslError>

Creates a BigNum from a decimal string.

pub fn from_hex_str(s: &str) -> Result<BigNum, SslError>

Creates a BigNum from a hexadecimal string.

pub unsafe fn new_from_ffi(orig: *mut BIGNUM) -> Result<BigNum, SslError>

pub fn new_from_slice(n: &[u8]) -> Result<BigNum, SslError>

Creates a new BigNum from an unsigned, big-endian encoded number of arbitrary length.

let bignum = BigNum::new_from_slice(&[0x12, 0x00, 0x34]).unwrap();

assert_eq!(bignum, BigNum::new_from(0x120034).unwrap());

pub fn checked_sqr(&self) -> Result<BigNum, SslError>

Returns the square of self.

let ref n = BigNum::new_from(10).unwrap();
let squared = BigNum::new_from(100).unwrap();

assert_eq!(n.checked_sqr().unwrap(), squared);
assert_eq!(n * n, squared);

pub fn checked_nnmod(&self, n: &BigNum) -> Result<BigNum, SslError>

Returns the unsigned remainder of the division self / n.

pub fn checked_mod_add(     &self,     a: &BigNum,     n: &BigNum ) -> Result<BigNum, SslError>

Equivalent to (self + a) mod n.

let ref s = BigNum::new_from(10).unwrap();
let ref a = BigNum::new_from(20).unwrap();
let ref n = BigNum::new_from(29).unwrap();
let result = BigNum::new_from(1).unwrap();

assert_eq!(s.checked_mod_add(a, n).unwrap(), result);

pub fn checked_mod_sub(     &self,     a: &BigNum,     n: &BigNum ) -> Result<BigNum, SslError>

Equivalent to (self - a) mod n.

pub fn checked_mod_mul(     &self,     a: &BigNum,     n: &BigNum ) -> Result<BigNum, SslError>

Equivalent to (self * a) mod n.

pub fn checked_mod_sqr(&self, n: &BigNum) -> Result<BigNum, SslError>

Equivalent to self² mod n.

pub fn checked_exp(&self, p: &BigNum) -> Result<BigNum, SslError>

Raises self to the pth power.

pub fn checked_mod_exp(     &self,     p: &BigNum,     n: &BigNum ) -> Result<BigNum, SslError>

Equivalent to self.checked_exp(p) mod n.

pub fn checked_mod_inv(&self, n: &BigNum) -> Result<BigNum, SslError>

Calculates the modular multiplicative inverse of self modulo n, that is, an integer r such that (self * r) % n == 1.

pub fn add_word(&mut self, w: c_ulong) -> Result<(), SslError>

Add an unsigned long to self. This is more efficient than adding a BigNum.

pub fn sub_word(&mut self, w: c_ulong) -> Result<(), SslError>

pub fn mul_word(&mut self, w: c_ulong) -> Result<(), SslError>

pub fn div_word(&mut self, w: c_ulong) -> Result<c_ulong, SslError>

pub fn mod_word(&self, w: c_ulong) -> Result<c_ulong, SslError>

pub fn checked_gcd(&self, a: &BigNum) -> Result<BigNum, SslError>

Computes the greatest common denominator of self and a.

pub fn checked_generate_prime(     bits: i32,     safe: bool,     add: Option<&BigNum>,     rem: Option<&BigNum> ) -> Result<BigNum, SslError>

Generates a prime number.

Parameters

• bits: The length of the prime in bits (lower bound).
• safe: If true, returns a "safe" prime p so that (p-1)/2 is also prime.
• add/rem: If add is set to Some(add), p % add == rem will hold, where p is the generated prime and rem is 1 if not specified (None).

pub fn is_prime(&self, checks: i32) -> Result<bool, SslError>

Checks whether self is prime.

Performs a Miller-Rabin probabilistic primality test with checks iterations.

Return Value

Returns true if self is prime with an error probability of less than 0.25 ^ checks.

pub fn is_prime_fast(     &self,     checks: i32,     do_trial_division: bool ) -> Result<bool, SslError>

Checks whether self is prime with optional trial division.

If do_trial_division is true, first performs trial division by a number of small primes. Then, like is_prime, performs a Miller-Rabin probabilistic primality test with checks iterations.

Return Value

Returns true if self is prime with an error probability of less than 0.25 ^ checks.

pub fn checked_new_random(     bits: i32,     prop: RNGProperty,     odd: bool ) -> Result<BigNum, SslError>

Generates a cryptographically strong pseudo-random BigNum.

Parameters

• bits: Length of the number in bits.
• prop: The desired properties of the number.
• odd: If true, the generated number will be odd.

pub fn checked_new_pseudo_random(     bits: i32,     prop: RNGProperty,     odd: bool ) -> Result<BigNum, SslError>

The cryptographically weak counterpart to checked_new_random.

pub fn checked_rand_in_range(&self) -> Result<BigNum, SslError>

Generates a cryptographically strong pseudo-random BigNum r in the range 0 <= r < self.

pub fn checked_pseudo_rand_in_range(&self) -> Result<BigNum, SslError>

The cryptographically weak counterpart to checked_rand_in_range.

pub fn set_bit(&mut self, n: i32) -> Result<(), SslError>

Sets bit n. Equivalent to self |= (1 << n).

When setting a bit outside of self, it is expanded.

pub fn clear_bit(&mut self, n: i32) -> Result<(), SslError>

Clears bit n, setting it to 0. Equivalent to self &= ~(1 << n).

When clearing a bit outside of self, an error is returned.

pub fn is_bit_set(&self, n: i32) -> bool

Returns true if the nth bit of self is set to 1, false otherwise.

pub fn mask_bits(&mut self, n: i32) -> Result<(), SslError>

Truncates self to the lowest n bits.

An error occurs if self is already shorter than n bits.

pub fn checked_shl1(&self) -> Result<BigNum, SslError>

Returns self, shifted left by 1 bit. self may be negative.

let ref s = BigNum::new_from(0b0100).unwrap();
let result = BigNum::new_from(0b1000).unwrap();

assert_eq!(s.checked_shl1().unwrap(), result);

let ref s = -BigNum::new_from(8).unwrap();
let result = -BigNum::new_from(16).unwrap();

// (-8) << 1 == -16
assert_eq!(s.checked_shl1().unwrap(), result);

pub fn checked_shr1(&self) -> Result<BigNum, SslError>

Returns self, shifted right by 1 bit. self may be negative.

pub fn checked_add(&self, a: &BigNum) -> Result<BigNum, SslError>

pub fn checked_sub(&self, a: &BigNum) -> Result<BigNum, SslError>

pub fn checked_mul(&self, a: &BigNum) -> Result<BigNum, SslError>

pub fn checked_div(&self, a: &BigNum) -> Result<BigNum, SslError>

pub fn checked_mod(&self, a: &BigNum) -> Result<BigNum, SslError>

pub fn checked_shl(&self, a: &i32) -> Result<BigNum, SslError>

pub fn checked_shr(&self, a: &i32) -> Result<BigNum, SslError>

pub fn negate(&mut self)

Inverts the sign of self.

let mut s = BigNum::new_from(8).unwrap();

s.negate();
assert_eq!(s, -BigNum::new_from(8).unwrap());
s.negate();
assert_eq!(s, BigNum::new_from(8).unwrap());

pub fn abs_cmp(&self, oth: BigNum) -> Ordering

Compare the absolute values of self and oth.

let s = -BigNum::new_from(8).unwrap();
let o = BigNum::new_from(8).unwrap();

assert_eq!(s.abs_cmp(o), Ordering::Equal);

pub fn is_negative(&self) -> bool

pub fn num_bits(&self) -> i32

Returns the number of significant bits in self.

pub fn num_bytes(&self) -> i32

Returns the size of self in bytes.

pub unsafe fn raw(&self) -> *mut BIGNUM

pub unsafe fn raw_ptr(&self) -> *const *mut BIGNUM

pub fn into_raw(self) -> *mut BIGNUM

Important traits for Vec<u8>

impl Write for Vec<u8>

pub fn to_vec(&self) -> Vec<u8>

Returns a big-endian byte vector representation of the absolute value of self.

self can be recreated by using new_from_slice.

let s = -BigNum::new_from(4543).unwrap();
let r = BigNum::new_from(4543).unwrap();

let s_vec = s.to_vec();
assert_eq!(BigNum::new_from_slice(&s_vec).unwrap(), r);

pub fn to_dec_str(&self) -> String

Returns a decimal string representation of self.

let s = -BigNum::new_from(12345).unwrap();

assert_eq!(s.to_dec_str(), "-12345");

pub fn to_hex_str(&self) -> String

Returns a hexadecimal string representation of self.

let s = -BigNum::new_from(0x99ff).unwrap();

assert_eq!(s.to_hex_str(), "-99FF");

Trait Implementations

impl<'a> Add<&'a BigNum> for &'a BigNum

type Output = BigNum

The resulting type after applying the + operator.

fn add(self, oth: &'a BigNum) -> BigNum

Performs the + operation.

impl<'a> Sub<&'a BigNum> for &'a BigNum

type Output = BigNum

The resulting type after applying the - operator.

fn sub(self, oth: &'a BigNum) -> BigNum

Performs the - operation.

impl<'a> Mul<&'a BigNum> for &'a BigNum

type Output = BigNum

The resulting type after applying the * operator.

fn mul(self, oth: &'a BigNum) -> BigNum

Performs the * operation.

impl<'a> Div<&'a BigNum> for &'a BigNum

type Output = BigNum

The resulting type after applying the / operator.

fn div(self, oth: &'a BigNum) -> BigNum

Performs the / operation.

impl<'a> Rem<&'a BigNum> for &'a BigNum

type Output = BigNum

The resulting type after applying the % operator.

fn rem(self, oth: &'a BigNum) -> BigNum

Performs the % operation.

impl<'a> Shl<i32> for &'a BigNum

type Output = BigNum

The resulting type after applying the << operator.

fn shl(self, n: i32) -> BigNum

Performs the << operation.

impl<'a> Shr<i32> for &'a BigNum

type Output = BigNum

The resulting type after applying the >> operator.

fn shr(self, n: i32) -> BigNum

Performs the >> operation.

impl Clone for BigNum

fn clone(&self) -> BigNum

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Neg for BigNum

type Output = BigNum

The resulting type after applying the - operator.

fn neg(self) -> BigNum

Performs the unary - operation.

impl Debug for BigNum

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

Formats the value using the given formatter.

impl Eq for BigNum

impl PartialEq for BigNum

fn eq(&self, oth: &BigNum) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

impl Ord for BigNum

fn cmp(&self, oth: &BigNum) -> Ordering

This method returns an Ordering between self and other.

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

Compares and returns the maximum of two values.

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

Compares and returns the minimum of two values.

impl PartialOrd for BigNum

fn partial_cmp(&self, oth: &BigNum) -> Option<Ordering>

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

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

This method tests less than (for self and other) and is used by the < operator.

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

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

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

This method tests greater than (for self and other) and is used by the > operator.

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

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

impl Drop for BigNum

fn drop(&mut self)

Executes the destructor for this type.