Struct BigNumRef

pub struct BigNumRef(/* private fields */);

Reference to a BigNum

Implementations

impl BigNumRef

pub fn clear(&mut self)

Erases the memory used by this BigNum, resetting its value to 0.

This can be used to destroy sensitive data such as keys when they are no longer needed.

This corresponds to BN_clear.

pub fn add_word(&mut self, w: u32) -> Result<(), ErrorStack>

Adds a u32 to self.

This corresponds to BN_add_word.

pub fn sub_word(&mut self, w: u32) -> Result<(), ErrorStack>

Subtracts a u32 from self.

This corresponds to BN_sub_word.

pub fn mul_word(&mut self, w: u32) -> Result<(), ErrorStack>

Multiplies a u32 by self.

This corresponds to BN_mul_word.

pub fn div_word(&mut self, w: u32) -> Result<u64, ErrorStack>

Divides self by a u32, returning the remainder.

This corresponds to BN_div_word.

pub fn mod_word(&self, w: u32) -> Result<u64, ErrorStack>

Returns the result of self modulo w.

This corresponds to BN_mod_word.

pub fn rand_range(&self, rnd: &mut BigNumRef) -> Result<(), ErrorStack>

Places a cryptographically-secure pseudo-random nonnegative number less than self in rnd.

This corresponds to BN_rand_range.

pub fn pseudo_rand_range(&self, rnd: &mut BigNumRef) -> Result<(), ErrorStack>

The cryptographically weak counterpart to rand_in_range.

This corresponds to BN_pseudo_rand_range.

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

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

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

This corresponds to BN_set_bit.

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

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

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

This corresponds to BN_clear_bit.

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

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

This corresponds to BN_is_bit_set.

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

Truncates self to the lowest n bits.

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

This corresponds to BN_mask_bits.

pub fn lshift1(&mut self, a: &BigNumRef) -> Result<(), ErrorStack>

Places a << 1 in self. Equivalent to self * 2.

This corresponds to BN_lshift1.

pub fn rshift1(&mut self, a: &BigNumRef) -> Result<(), ErrorStack>

Places a >> 1 in self. Equivalent to self / 2.

This corresponds to BN_rshift1.

pub fn checked_add( &mut self, a: &BigNumRef, b: &BigNumRef, ) -> Result<(), ErrorStack>

Places a + b in self. core::ops::Add is also implemented for BigNumRef.

This corresponds to BN_add.

pub fn checked_sub( &mut self, a: &BigNumRef, b: &BigNumRef, ) -> Result<(), ErrorStack>

Places a - b in self. core::ops::Sub is also implemented for BigNumRef.

This corresponds to BN_sub.

pub fn lshift(&mut self, a: &BigNumRef, n: i32) -> Result<(), ErrorStack>

Places a << n in self. Equivalent to a * 2 ^ n.

This corresponds to BN_lshift.

pub fn rshift(&mut self, a: &BigNumRef, n: i32) -> Result<(), ErrorStack>

Places a >> n in self. Equivalent to a / 2 ^ n.

This corresponds to BN_rshift.

pub fn to_owned(&self) -> Result<BigNum, ErrorStack>

Creates a new BigNum with the same value.

This corresponds to BN_dup.

pub fn set_negative(&mut self, negative: bool)

Sets the sign of self. Pass true to set self to a negative. False sets self positive.

This corresponds to BN_set_negative.

pub fn ucmp(&self, oth: &BigNumRef) -> Ordering

Compare the absolute values of self and oth.

Examples

let s = -BigNum::from_u32(8).unwrap();
let o = BigNum::from_u32(8).unwrap();

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

This corresponds to BN_ucmp.

pub fn is_negative(&self) -> bool

Returns true if self is negative.

This corresponds to BN_is_negative.

pub fn is_even(&self) -> bool

Returns true is self is even.

This corresponds to BN_is_even.

pub fn is_odd(&self) -> bool

Returns true is self is odd.

This corresponds to BN_is_odd.

pub fn num_bits(&self) -> i32

Returns the number of significant bits in self.

This corresponds to BN_num_bits.

pub fn num_bytes(&self) -> i32

Returns the size of self in bytes. Implemented natively.

pub fn rand( &mut self, bits: i32, msb: MsbOption, odd: bool, ) -> Result<(), ErrorStack>

Generates a cryptographically strong pseudo-random BigNum, placing it in self.

Parameters

• bits: Length of the number in bits.
• msb: The desired properties of the most significant bit. See constants.
• odd: If true, the generated number will be odd.

Examples

use openssl::bn::{BigNum, MsbOption};
use openssl::error::ErrorStack;

fn generate_random() -> Result< BigNum, ErrorStack > {
   let mut big = BigNum::new()?;

   // Generates a 128-bit odd random number
   big.rand(128, MsbOption::MAYBE_ZERO, true);
   Ok((big))
}

This corresponds to BN_rand.

pub fn pseudo_rand( &mut self, bits: i32, msb: MsbOption, odd: bool, ) -> Result<(), ErrorStack>

The cryptographically weak counterpart to rand. Not suitable for key generation.

This corresponds to BN_pseudo_rand.

pub fn generate_prime( &mut self, bits: i32, safe: bool, add: Option<&BigNumRef>, rem: Option<&BigNumRef>, ) -> Result<(), ErrorStack>

Generates a prime number, placing it in self.

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).

Examples

use openssl::bn::BigNum;
use openssl::error::ErrorStack;

fn generate_weak_prime() -> Result< BigNum, ErrorStack > {
   let mut big = BigNum::new()?;

   // Generates a 128-bit simple prime number
   big.generate_prime(128, false, None, None);
   Ok((big))
}

This corresponds to BN_generate_prime_ex.

pub fn checked_mul( &mut self, a: &BigNumRef, b: &BigNumRef, ctx: &mut BigNumContextRef, ) -> Result<(), ErrorStack>

Places the result of a * b in self. core::ops::Mul is also implemented for BigNumRef.

This corresponds to BN_mul.

pub fn checked_div( &mut self, a: &BigNumRef, b: &BigNumRef, ctx: &mut BigNumContextRef, ) -> Result<(), ErrorStack>

Places the result of a / b in self. The remainder is discarded. core::ops::Div is also implemented for BigNumRef.

This corresponds to BN_div.

pub fn checked_rem( &mut self, a: &BigNumRef, b: &BigNumRef, ctx: &mut BigNumContextRef, ) -> Result<(), ErrorStack>

Places the result of a % b in self.

This corresponds to BN_div.

pub fn div_rem( &mut self, rem: &mut BigNumRef, a: &BigNumRef, b: &BigNumRef, ctx: &mut BigNumContextRef, ) -> Result<(), ErrorStack>

Places the result of a / b in self and a % b in rem.

This corresponds to BN_div.

pub fn sqr( &mut self, a: &BigNumRef, ctx: &mut BigNumContextRef, ) -> Result<(), ErrorStack>

Places the result of a² in self.

This corresponds to BN_sqr.

pub fn nnmod( &mut self, a: &BigNumRef, m: &BigNumRef, ctx: &mut BigNumContextRef, ) -> Result<(), ErrorStack>

Places the result of a mod m in self. As opposed to div_rem the result is non-negative.

This corresponds to BN_nnmod.

pub fn mod_add( &mut self, a: &BigNumRef, b: &BigNumRef, m: &BigNumRef, ctx: &mut BigNumContextRef, ) -> Result<(), ErrorStack>

Places the result of (a + b) mod m in self.

This corresponds to BN_mod_add.

pub fn mod_sub( &mut self, a: &BigNumRef, b: &BigNumRef, m: &BigNumRef, ctx: &mut BigNumContextRef, ) -> Result<(), ErrorStack>

Places the result of (a - b) mod m in self.

This corresponds to BN_mod_sub.

pub fn mod_mul( &mut self, a: &BigNumRef, b: &BigNumRef, m: &BigNumRef, ctx: &mut BigNumContextRef, ) -> Result<(), ErrorStack>

Places the result of (a * b) mod m in self.

This corresponds to BN_mod_mul.

pub fn mod_sqr( &mut self, a: &BigNumRef, m: &BigNumRef, ctx: &mut BigNumContextRef, ) -> Result<(), ErrorStack>

Places the result of a² mod m in self.

This corresponds to BN_mod_sqr.

pub fn mod_sqrt( &mut self, a: &BigNumRef, p: &BigNumRef, ctx: &mut BigNumContextRef, ) -> Result<(), ErrorStack>

Places into self the modular square root of a such that self^2 = a (mod p)

This corresponds to BN_mod_sqrt.

pub fn exp( &mut self, a: &BigNumRef, p: &BigNumRef, ctx: &mut BigNumContextRef, ) -> Result<(), ErrorStack>

Places the result of a^p in self.

This corresponds to BN_exp.

pub fn mod_exp( &mut self, a: &BigNumRef, p: &BigNumRef, m: &BigNumRef, ctx: &mut BigNumContextRef, ) -> Result<(), ErrorStack>

Places the result of a^p mod m in self.

This corresponds to BN_mod_exp.

pub fn mod_inverse( &mut self, a: &BigNumRef, n: &BigNumRef, ctx: &mut BigNumContextRef, ) -> Result<(), ErrorStack>

Places the inverse of a modulo n in self.

This corresponds to BN_mod_inverse.

pub fn gcd( &mut self, a: &BigNumRef, b: &BigNumRef, ctx: &mut BigNumContextRef, ) -> Result<(), ErrorStack>

Places the greatest common denominator of a and b in self.

This corresponds to BN_gcd.

pub fn is_prime( &self, checks: i32, ctx: &mut BigNumContextRef, ) -> Result<bool, ErrorStack>

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.

This corresponds to BN_is_prime_ex.

pub fn is_prime_fasttest( &self, checks: i32, ctx: &mut BigNumContextRef, do_trial_division: bool, ) -> Result<bool, ErrorStack>

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.

This corresponds to BN_is_prime_fasttest_ex.

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 from_slice.

let s = -BigNum::from_u32(4543).unwrap();
let r = BigNum::from_u32(4543).unwrap();

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

This corresponds to BN_bn2bin.

pub fn to_vec_padded(&self, pad_to: i32) -> Result<Vec<u8>, ErrorStack>

Returns a big-endian byte vector representation of the absolute value of self padded to pad_to bytes.

If pad_to is less than self.num_bytes() then an error is returned.

self can be recreated by using from_slice.

let bn = BigNum::from_u32(0x4543).unwrap();

let bn_vec = bn.to_vec_padded(4).unwrap();
assert_eq!(&bn_vec, &[0, 0, 0x45, 0x43]);

let r = bn.to_vec_padded(1);
assert!(r.is_err());

let bn = -BigNum::from_u32(0x4543).unwrap();
let bn_vec = bn.to_vec_padded(4).unwrap();
assert_eq!(&bn_vec, &[0, 0, 0x45, 0x43]);

This corresponds to BN_bn2binpad.

pub fn to_dec_str(&self) -> Result<OpensslString, ErrorStack>

Returns a decimal string representation of self.

let s = -BigNum::from_u32(12345).unwrap();

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

This corresponds to BN_bn2dec.

pub fn to_hex_str(&self) -> Result<OpensslString, ErrorStack>

Returns a hexadecimal string representation of self.

let s = -BigNum::from_u32(0x99ff).unwrap();

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

This corresponds to BN_bn2hex.

pub fn to_asn1_integer(&self) -> Result<Asn1Integer, ErrorStack>

Returns an Asn1Integer containing the value of self.

This corresponds to BN_to_ASN1_INTEGER.

pub fn set_const_time(&mut self)

Force constant time computation on this value.

This corresponds to BN_set_flags.

pub fn is_const_time(&self) -> bool

Returns true if self is in const time mode.

This corresponds to BN_get_flags.

pub fn is_secure(&self) -> bool

Returns true if self was created with BigNum::new_secure.

This corresponds to BN_get_flags.

Trait Implementations

impl<'a, 'b> Add<&'b BigNum> for &'a BigNumRef

type Output = BigNum

The resulting type after applying the + operator.

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

Performs the + operation.

impl<'a, 'b> Add<&'b BigNumRef> for &'a BigNum

type Output = BigNum

The resulting type after applying the + operator.

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

Performs the + operation.

impl Add<&BigNumRef> for &BigNumRef

type Output = BigNum

The resulting type after applying the + operator.

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

Performs the + operation.

impl AsRef<BigNumRef> for BigNum

fn as_ref(&self) -> &BigNumRef

Converts this type into a shared reference of the (usually inferred) input type.

impl Borrow<BigNumRef> for BigNum

fn borrow(&self) -> &BigNumRef

Immutably borrows from an owned value.

impl Debug for BigNumRef

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

Formats the value using the given formatter.

impl Display for BigNumRef

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

Formats the value using the given formatter.

impl<'a, 'b> Div<&'b BigNum> for &'a BigNumRef

type Output = BigNum

The resulting type after applying the / operator.

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

Performs the / operation.

impl<'a, 'b> Div<&'b BigNumRef> for &'a BigNum

type Output = BigNum

The resulting type after applying the / operator.

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

Performs the / operation.

impl<'b> Div<&'b BigNumRef> for &BigNumRef

type Output = BigNum

The resulting type after applying the / operator.

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

Performs the / operation.

impl ForeignTypeRef for BigNumRef

type CType = BIGNUM

The raw C type.

unsafe fn from_ptr<'a>(ptr: *mut Self::CType) -> &'a Self

Constructs a shared instance of this type from its raw type.

unsafe fn from_ptr_mut<'a>(ptr: *mut Self::CType) -> &'a mut Self

Constructs a mutable reference of this type from its raw type.

fn as_ptr(&self) -> *mut Self::CType

Returns a raw pointer to the wrapped value.

impl<'a, 'b> Mul<&'b BigNum> for &'a BigNumRef

type Output = BigNum

The resulting type after applying the * operator.

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

Performs the * operation.

impl<'a, 'b> Mul<&'b BigNumRef> for &'a BigNum

type Output = BigNum

The resulting type after applying the * operator.

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

Performs the * operation.

impl Mul<&BigNumRef> for &BigNumRef

type Output = BigNum

The resulting type after applying the * operator.

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

Performs the * operation.

impl Neg for &BigNumRef

type Output = BigNum

The resulting type after applying the - operator.

fn neg(self) -> BigNum

Performs the unary - operation.

impl Ord for BigNumRef

fn cmp(&self, oth: &BigNumRef) -> 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<BigNum> for BigNumRef

fn eq(&self, oth: &BigNum) -> 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 PartialEq<BigNumRef> for BigNum

fn eq(&self, oth: &BigNumRef) -> 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 PartialEq for BigNumRef

fn eq(&self, oth: &BigNumRef) -> 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<BigNum> for BigNumRef

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

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 PartialOrd<BigNumRef> for BigNum

fn partial_cmp(&self, oth: &BigNumRef) -> 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 PartialOrd for BigNumRef

fn partial_cmp(&self, oth: &BigNumRef) -> 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<'a, 'b> Rem<&'b BigNum> for &'a BigNumRef

type Output = BigNum

The resulting type after applying the % operator.

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

Performs the % operation.

impl<'a, 'b> Rem<&'b BigNumRef> for &'a BigNum

type Output = BigNum

The resulting type after applying the % operator.

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

Performs the % operation.

impl<'b> Rem<&'b BigNumRef> for &BigNumRef

type Output = BigNum

The resulting type after applying the % operator.

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

Performs the % operation.

impl Shl<i32> for &BigNumRef

type Output = BigNum

The resulting type after applying the << operator.

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

Performs the << operation.

impl Shr<i32> for &BigNumRef

type Output = BigNum

The resulting type after applying the >> operator.

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

Performs the >> operation.

impl<'a, 'b> Sub<&'b BigNum> for &'a BigNumRef

type Output = BigNum

The resulting type after applying the - operator.

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

Performs the - operation.

impl<'a, 'b> Sub<&'b BigNumRef> for &'a BigNum

type Output = BigNum

The resulting type after applying the - operator.

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

Performs the - operation.

impl Sub<&BigNumRef> for &BigNumRef

type Output = BigNum

The resulting type after applying the - operator.

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

Performs the - operation.

impl Eq for BigNumRef

impl Send for BigNumRef

impl Sync for BigNumRef