Module hash_mldsa 

This implements the HashML-DSA algorithm specified in FIPS 204 which is useful for cases where the user needs to process the to-be-signed message in chunks, and they use the external mu mode of MLDSA; possibly because the message needs to be digested before knowing which public key will sign it.

HashML-DSA is a full signature algorithm implementing the Signer and SignatureVerifier traits:

use bouncycastle_core::errors::SignatureError;
use bouncycastle_mldsa::{HashMLDSA65_with_SHA512, MLDSATrait, HashMLDSA44_with_SHA512};
use bouncycastle_core::traits::{Signer, SignatureVerifier};

let msg = b"The quick brown fox jumped over the lazy dog";

let (pk, sk) = HashMLDSA65_with_SHA512::keygen().unwrap();

let sig = HashMLDSA65_with_SHA512::sign(&sk, msg, None).unwrap();
// This is the signature value that can be saved to a file or whatever it is need.

match HashMLDSA65_with_SHA512::verify(&pk, msg, None, &sig) {
    Ok(()) => println!("Signature is valid!"),
    Err(SignatureError::SignatureVerificationFailed) => println!("Signature is invalid!"),
    Err(e) => panic!("Something else went wrong: {:?}", e),
}

But the user also has access to the pre-hashed functions available from PHSigner and PHSignatureVerifier:

use bouncycastle_core::errors::SignatureError;
use bouncycastle_mldsa::{HashMLDSA65_with_SHA512, MLDSATrait, HashMLDSA44_with_SHA512};
use bouncycastle_core::traits::{
    Hash, PHSignatureVerifier, PHSigner, SignatureVerifier, Signer,
};
use bouncycastle_sha2::SHA512;

let msg = b"The quick brown fox jumped over the lazy dog";

// Here, and in contrast to External Mu mode of ML-DSA, the message can be pre-hashed before
// even generating the signing key.
let ph: [u8; 64] = SHA512::default().hash(msg).as_slice().try_into().unwrap();


let (pk, sk) = HashMLDSA65_with_SHA512::keygen().unwrap();

let sig = HashMLDSA65_with_SHA512::sign_ph(&sk, &ph, None).unwrap();
// This is the signature value that can be saved to a file or whatever it is need.

// This verifies either through the usual one-shot API of the [SignatureVerifier] trait
match HashMLDSA65_with_SHA512::verify(&pk, msg, None, &sig) {
    Ok(()) => println!("Signature is valid!"),
    Err(SignatureError::SignatureVerificationFailed) => println!("Signature is invalid!"),
    Err(e) => panic!("Something else went wrong: {:?}", e),
}

// Or though the verify_ph of the [PHSignatureVerifier] trait
match HashMLDSA65_with_SHA512::verify_ph(&pk, &ph, None, &sig) {
    Ok(()) => println!("Signature is valid!"),
    Err(SignatureError::SignatureVerificationFailed) => println!("Signature is invalid!"),
    Err(e) => panic!("Something else went wrong: {:?}", e),
}

Note that the HashMLDSA object is just a light wrapper around MLDSA, and, for example, they share key types, so if more sophisticated keygen functions are needed, just use them from MLDSA. But a simple HashMLDSA::keygen is provided.

Structs

HashMLDSA

An instance of the HashML-DSA algorithm.

Constants

HASH_ML_DSA_44_with_SHA256_NAME

HASH_ML_DSA_44_with_SHA512_NAME

HASH_ML_DSA_65_WITH_SHA256_NAME

HASH_ML_DSA_65_WITH_SHA512_NAME

HASH_ML_DSA_87_WITH_SHA512_NAME

HASH_ML_DSA_87_with_SHA256_NAME

Type Aliases

HashMLDSA44_with_SHA256

The HashML-DSA-44_with_SHA512 signature algorithm.

HashMLDSA44_with_SHA512

The HashML-DSA-44_with_SHA512 signature algorithm.

HashMLDSA65_with_SHA256

The HashML-DSA-65_with_SHA256 signature algorithm.

HashMLDSA65_with_SHA512

The HashML-DSA-65_with_SHA512 signature algorithm.

HashMLDSA87_with_SHA256

The HashML-DSA-87_with_SHA256 signature algorithm.

HashMLDSA87_with_SHA512

The HashML-DSA-87_with_SHA512 signature algorithm.