Enum Error 

pub enum Error {
    InvalidLength {
        what: &'static str,
        expected: usize,
        got: usize,
    },
    InvalidPoint,
    InvalidIdentityPoint,
    InvalidScalar,
    InvalidSecretKey,
    InvalidHex,
    InvalidPrefix {
        expected: &'static str,
        got: String,
    },
    InvalidChecksum,
    SignerNotInRing,
    RingTooSmall,
    DuplicateRingMember,
    EmptyVote,
    EmptyElectionId,
}

Anything that can go wrong when parsing or processing inputs.

Note that a signature being mathematically invalid is not an error — it is a false return from crate::verify_vote. An Error is only produced when the caller hands us malformed bytes (wrong length, not on the curve, etc.) or asks for an operation that does not make sense (e.g. signing with a key that is not in the authorised ring).

Variants

InvalidLength

A byte slice did not have the size required for the type it was supposed to decode into.

Fields

what: &'static str

Human-readable name of the value being decoded.

expected: usize

Number of bytes that were expected.

got: usize

Number of bytes that were actually provided.

InvalidPoint

32 bytes that do not represent a valid Ristretto255 point.

InvalidIdentityPoint

A Ristretto255 point decoded correctly but is the identity point, which is not a valid public protocol value.

InvalidScalar

32 bytes that do not represent a canonical scalar (mod ℓ).

InvalidSecretKey

A scalar decoded correctly but is not usable as a secret key.

InvalidHex

The hex string handed to a *_from_hex constructor could not be decoded.

InvalidPrefix

A prefixed string (e.g. pk_…) handed to a *_from_prefixed constructor was not in the expected three-part shape, or carried the wrong tag for the type being decoded (e.g. a ki_ value where a pk_ one was required).

Fields

expected: &'static str

The tag the constructor required, without the trailing _ ("pk", "sk", "ki" or "blsag").

got: String

The tag actually found, or empty when the string was not even in tag_body_checksum shape. Never echoes the value’s body, so it cannot leak secret-key material.

InvalidChecksum

A prefixed string decoded structurally but its trailing checksum did not match the body — the value was almost certainly mistyped, truncated or corrupted in transit.

SignerNotInRing

sign_vote was called with a secret key whose public key is not in the supplied authorised ring. Signing would still mathematically produce something, but it would not verify, so we refuse it early.

RingTooSmall

sign_vote or verify_vote was called with an authorised ring containing fewer than two members. A ring of one trivially de-anonymises the signer, so we reject it.

DuplicateRingMember

sign_vote was given a ring containing the same public key twice. The protocol’s anonymity guarantees assume distinct members, and we refuse to silently de-duplicate.

EmptyVote

sign_vote was called with a zero-byte ballot. The library has no opinion on the payload format, but an empty payload is almost always a caller bug (forgot to serialise the form, fed in the wrong variable, …) so we surface it instead of silently signing nothing.

EmptyElectionId

sign_vote was called with a zero-byte election identifier. Allowing it would defeat the whole point of binding signatures to an election context, so we refuse early.

Trait Implementations

impl Clone for Error

fn clone(&self) -> Error

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Error

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

Formats the value using the given formatter.

impl Display for Error

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

Formats the value using the given formatter.

impl Eq for Error

impl Error for Error

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl PartialEq for Error

fn eq(&self, other: &Error) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Error