Crate crypto_dispatch 

Algorithm dispatch and structural validation.

This crate is the runtime seam between an Algorithm selector and the concrete primitive that implements it. Given an algorithm value it routes keygen, sign/verify, key agreement, and KEM encapsulate/decapsulate to the matching primitive adapter, and it binds public keys to their multicodec/multikey encodings.

Two safety properties are enforced here rather than left to callers: verify fails closed — an invalid signature is an AlgorithmError::SignatureInvalid, never Ok(false) — and every secret returned (generated private keys, shared secrets, decapsulated secrets) is carried in a zeroizing wrapper. Length and key-shape checks are performed by the selected primitive’s typed constructors and are exercised by dispatch-level negative tests so algorithm routing cannot silently truncate, pad, or reinterpret caller bytes.

Constant-time behavior for authentication comparisons is inherited from the wrapped primitive crates. Dispatch does not reimplement tag, MAC, or signature comparison logic; it routes to the primitive verifier and maps the verifier’s typed failure into this crate’s fail-closed result.

reallyme-crypto-dispatch

reallyme-crypto-dispatch owns algorithm-selected signatures, key agreement, key encapsulation, and public-key encoding. It is normally consumed through the public reallyme-crypto facade.

Dispatch operations fail closed with typed AlgorithmError values. Secret outputs use zeroizing owners, and primitive crates retain responsibility for cryptographic validation and constant-time verification.

Fail-closed signature verification

// This example requires the `ed25519` feature.
use crypto_core::Algorithm;
use crypto_dispatch::{generate_keypair, sign, verify};

let (public, secret) = generate_keypair(Algorithm::Ed25519)?;
let signature = sign(Algorithm::Ed25519, &secret, b"message")?;
verify(Algorithm::Ed25519, &public, b"message", &signature)?;

// Invalid signatures are typed errors, never `Ok(false)`.
assert!(verify(Algorithm::Ed25519, &public, b"tampered", &signature).is_err());

Hash ownership

Hash selection is owned by reallyme_crypto::operations::hash, leaving one semantic hash selector. Applications should use reallyme_crypto::dispatch::hash_digest; adapters should call reallyme_crypto::operations::hash::digest directly.

MAC ownership

MAC selection is owned by reallyme_crypto::operations::mac, leaving one semantic MAC selector. Applications should use reallyme_crypto::dispatch::{mac_authenticate, mac_verify}; adapters should call reallyme_crypto::operations::mac directly.

AEAD ownership

AEAD selection is owned by reallyme_crypto::operations::aead, leaving one semantic AEAD selector. Applications should use reallyme_crypto::dispatch::{aead_encrypt, aead_decrypt}; adapters should call reallyme_crypto::operations::aead directly.

Re-exports

pub use error::AlgorithmError;

pub use registry::derive_keypair;

pub use registry::derive_shared_secret;

pub use registry::generate_keypair;

pub use registry::kem_decapsulate;

pub use registry::kem_encapsulate;

pub use registry::sign;

pub use registry::verify;

pub use keypair::generate_multikey_keypair;

pub use keypair::GeneratedKeypair;

pub use multikey::public_key_to_multikey;

pub use provider::provider_decision;

pub use provider::FallbackPolicy;

pub use provider::KeyCopyBoundary;

pub use provider::KeyResidency;

pub use provider::ProviderDecision;

pub use provider::ProviderDisposition;

pub use provider::ProviderKind;

pub use provider::ProviderLane;

pub use provider::ProviderOperation;

pub use provider::ProviderOutputPolicy;

pub use provider::ProviderPolicyReason;

pub use validation::validate_verification_method_multikey;

Modules

algorithms

Per-algorithm adapters wiring selectors to concrete primitives.

error

Error type returned by dispatch operations.

keypair

Keypair generation with multikey-encoded public keys.

multikey

Multicodec/multikey encoding of public keys.

provider

Explicit provider selection, custody, lane, and fallback decisions. Inspectable provider decisions for algorithm-selected dispatch.

registry

Runtime dispatch entry points for sign/verify, key agreement, and KEM.

traits

Adapter traits implemented by each algorithm primitive.

validation

Structural validation of verification-method multikeys.