Crate crypto_bigint

Pure Rust implementation of a big integer library designed for cryptography.

About

This library has been designed from the ground-up for use in cryptographic applications. It provides constant-time, no_std-friendly implementations of modern formulas implemented using const generics.

Minimum Supported Rust Version

Rust 1.51 at a minimum.

Goals

• No heap allocations i.e. no_std-friendly.
• Constant-time by default using traits from the subtle crate.
• Leverage what is possible today with const generics on stable rust.
• Support const fn as much as possible, including decoding big integers from bytes/hex and performing arithmetic operations on them, with the goal of being able to compute values at compile-time.

Status

This library presently provides only a baseline level of functionality. It’s new, unaudited, and may contain bugs. We recommend that it only be used in an experimental capacity for now.

Please see the feature wishlist tracking ticket for more information.

generic-array interop

When the optional generic-array feature is enabled, this library provides an ArrayEncoding trait which can be used to serialize/deserialize big integer values as GenericArray<u8, N>.

Re-exports

pub use crate::limb::Limb;

pub use subtle;

pub use generic_array;

Modules

consts

Type aliases for many constants.

limb

Big integers are represented as an array of smaller CPU word-size integers called “limbs”.

Macros

nlimbs

Calculate the number of limbs required to represent the given number of bits.

Structs

Checked

Provides intentionally-checked arithmetic on T.

UInt

Big unsigned integer.

Wrapping

Provides intentionally-wrapped arithmetic on T.

Constants

LIMB_BYTESDeprecated

Number of bytes in a Limb.

Traits

AddMod

Compute self + rhs mod p.

ArrayEncodinggeneric-array

Support for encoding a big integer as a GenericArray.

Concat

Concatenate two numbers into a “wide” twice-width value, using the rhs value as the least significant value.

Encoding

Encoding support.

MulMod

Compute self * rhs mod p.

NegMod

Compute -self mod p.

Split

Split a number in half, returning the most significant half followed by the least significant.

SubMod

Compute self - rhs mod p.

Type Definitions

ByteArraygeneric-array

Alias for a byte array whose size is defined by ArrayEncoding::ByteSize.

U64

64-bit unsigned big integer

U128

128-bit unsigned big integer

U192

192-bit unsigned big integer

U256

256-bit unsigned big integer

U384

384-bit unsigned big integer

U448

448-bit unsigned big integer

U512

512-bit unsigned big integer

U768

768-bit unsigned big integer

U896

896-bit unsigned big integer

U1024

1024-bit unsigned big integer

U1536

1536-bit unsigned big integer

U1792

1792-bit unsigned big integer

U2048

2048-bit unsigned big integer

U3072

3072-bit unsigned big integer

U3584

3584-bit unsigned big integer

U4096

4096-bit unsigned big integer

U6144

6144-bit unsigned big integer

U8192

8192-bit unsigned big integer