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 subtle;
pub use generic_array;

Modules

consts

Type aliases for many constants.

Macros

nlimbs

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

Structs

Checked	Provides intentionally-checked arithmetic on T.
Limb	Big integers are represented as an array of smaller CPU word-size integers called “limbs”.
UInt	Big unsigned integer.
Wrapping	Provides intentionally-wrapped arithmetic on T.

Constants

LIMB_BYTES

Number of bytes in a Limb.

Traits

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

Type Definitions

ByteArray	generic-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