Struct TaskSigner 

pub struct TaskSigner { /* private fields */ }

Signs and verifies task messages with a shared secret using HMAC-SHA256.

A TaskSigner holds the secret key. Producers call TaskSigner::sign to obtain a TaskSignature; consumers call TaskSigner::verify (or TaskSigner::verify_optional) to authenticate a received message.

Implementations

impl TaskSigner

pub fn new(key: impl AsRef<[u8]>) -> Self

Create a signer from a shared secret key.

Any key length is accepted (HMAC handles short and long keys), but for HMAC-SHA256 a key of at least 32 bytes of entropy is recommended.

pub fn mac(&self, fields: &SignedFields) -> [u8; 32]

Compute the raw MAC tag bytes over the canonical serialization.

pub fn sign(&self, fields: &SignedFields) -> TaskSignature

Sign a set of task fields, returning a serializable TaskSignature.

pub fn verify( &self, fields: &SignedFields, signature: &TaskSignature, ) -> Result<(), SignatureError>

Verify a task message against its signature.

The comparison is constant-time. Any tampering with the signed fields, a wrong key, or a corrupted/forged tag yields an error.

Errors

• SignatureError::UnsupportedAlgorithm if the signature names an algorithm other than HMAC-SHA256.
• SignatureError::MalformedSignature if the tag is not valid hex or has the wrong length.
• SignatureError::Mismatch if the recomputed MAC does not match.

pub fn verify_optional( &self, fields: &SignedFields, signature: Option<&TaskSignature>, ) -> Result<(), SignatureError>

Verify a message whose signature may be absent.

When signature is None this returns SignatureError::MissingSignature, which lets a caller distinguish an unsigned message from a badly-signed one and reject both.

Errors

Returns SignatureError::MissingSignature when no signature is supplied, or any error from TaskSigner::verify otherwise.

pub fn is_valid(&self, fields: &SignedFields, signature: &TaskSignature) -> bool

Convenience predicate: true iff the message verifies.

Trait Implementations

impl Clone for TaskSigner

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for TaskSigner

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.