Crate pq_oid 

pq-oid - Type-safe OID constants for post-quantum algorithms

This crate provides OID (Object Identifier) constants and utilities for post-quantum cryptographic algorithms as defined in FIPS 203, 204, and 205.

Features

• Type-safe enums for ML-KEM, ML-DSA, and SLH-DSA algorithm families
• Ergonomic conversions via FromStr, TryFrom<&str>, and Display
• Direct access to algorithm properties (key sizes, security levels, OIDs)
• DER encoding/decoding of OIDs
• JOSE and COSE mappings for ML-DSA

Quick Start

use pq_oid::{MlKem, MlDsa, SlhDsa, Algorithm};
use std::str::FromStr;

// Parse from string
let kem: MlKem = "ML-KEM-512".parse().unwrap();
assert_eq!(kem.oid(), "2.16.840.1.101.3.4.4.1");
assert_eq!(kem.public_key_size(), 800);

// Or use try_into
let dsa: MlDsa = "ML-DSA-65".try_into().unwrap();
assert_eq!(dsa.jose(), "ML-DSA-65");
assert_eq!(dsa.cose(), -49);

// Convert back to string
let name: &str = kem.as_ref();
assert_eq!(name, "ML-KEM-512");

// Unified algorithm type
let alg: Algorithm = MlKem::Kem512.into();
assert_eq!(alg.family(), pq_oid::AlgorithmFamily::MlKem);

Algorithm Families

ML-KEM (FIPS 203)

Module-Lattice-Based Key-Encapsulation Mechanism:

• MlKem::Kem512 - NIST Level 1
• MlKem::Kem768 - NIST Level 3
• MlKem::Kem1024 - NIST Level 5

ML-DSA (FIPS 204)

Module-Lattice-Based Digital Signature Algorithm:

• MlDsa::Dsa44 - NIST Level 2
• MlDsa::Dsa65 - NIST Level 3
• MlDsa::Dsa87 - NIST Level 5

SLH-DSA (FIPS 205)

Stateless Hash-Based Digital Signature Algorithm with SHA2 and SHAKE variants in both “small” (s) and “fast” (f) modes.

Modules

oid

OID constants for all algorithms.

Structs

AlgorithmInfo

Information about a specific algorithm variant.

Enums

Algorithm

A unified enum representing any supported PQ algorithm.

AlgorithmFamily

The algorithm family.

AlgorithmSizes

Type-specific sizes for algorithms.

AlgorithmType

The type of cryptographic algorithm.

Error

Error type for pq-oid operations.

HashFunction

The hash function used by SLH-DSA.

MlDsa

ML-DSA (Module-Lattice-Based Digital Signature Algorithm) variants.

MlKem

ML-KEM (Module-Lattice-Based Key-Encapsulation Mechanism) variants.

SecurityLevel

NIST security level.

SlhDsa

SLH-DSA (Stateless Hash-Based Digital Signature Algorithm) variants.

SlhDsaMode

The speed/size tradeoff mode for SLH-DSA.

Functions

decode_oid

Decode DER bytes to an OID string.

encode_oid

Encode an OID string to DER bytes (without the tag and length).

encode_oid_to

Encode an OID string to DER bytes, writing to the provided buffer.

Type Aliases

Result

Result type for pq-oid operations.