Struct ecdsa::RecoveryId

pub struct RecoveryId(_);

Recovery IDs, a.k.a. “recid”.

This is an integer value 0, 1, 2, or 3 included along with a signature which is used during the recovery process to select the correct public key from the signature.

It consists of two bits of information:

• low bit (0/1): was the y-coordinate of the affine point resulting from the fixed-base multiplication 𝑘×𝑮 odd? This part of the algorithm functions similar to point decompression.
• hi bit (3/4): did the affine x-coordinate of 𝑘×𝑮 overflow the order of the scalar field, requiring a reduction when computing r?

Implementations

impl RecoveryId

pub const MAX: u8 = 3u8

Maximum supported value for the recovery ID (inclusive).

pub const fn new(is_y_odd: bool, is_x_reduced: bool) -> Self

Create a new RecoveryId from the following 1-bit arguments:

• is_y_odd: is the affine y-coordinate of 𝑘×𝑮 odd?
• is_x_reduced: did the affine x-coordinate of 𝑘×𝑮 overflow the curve order?

pub const fn is_x_reduced(self) -> bool

Did the affine x-coordinate of 𝑘×𝑮 overflow the curve order?

pub const fn is_y_odd(self) -> bool

Is the affine y-coordinate of 𝑘×𝑮 odd?

pub const fn from_byte(byte: u8) -> Option<Self>

Convert a u8 into a RecoveryId.

pub const fn to_byte(self) -> u8

Convert this RecoveryId into a u8.

impl RecoveryId

pub fn trial_recovery_from_msg<C>(
    verifying_key: &VerifyingKey<C>,
    msg: &[u8],
    signature: &Signature<C>
) -> Result<Self>where
    C: DigestPrimitive + PrimeCurve + ProjectiveArithmetic,
    AffinePoint<C>: DecompressPoint<C> + FromEncodedPoint<C> + ToEncodedPoint<C> + VerifyPrimitive<C>,
    FieldSize<C>: ModulusSize,
    Scalar<C>: Reduce<C::UInt>,
    SignatureSize<C>: ArrayLength<u8>,

Available on crate feature verifying only.

Given a public key, message, and signature, use trial recovery to determine if a suitable recovery ID exists, or return an error otherwise.

pub fn trial_recovery_from_digest<C, D>(
    verifying_key: &VerifyingKey<C>,
    digest: D,
    signature: &Signature<C>
) -> Result<Self>where
    C: PrimeCurve + ProjectiveArithmetic,
    D: Digest,
    AffinePoint<C>: DecompressPoint<C> + FromEncodedPoint<C> + ToEncodedPoint<C> + VerifyPrimitive<C>,
    FieldSize<C>: ModulusSize,
    Scalar<C>: Reduce<C::UInt>,
    SignatureSize<C>: ArrayLength<u8>,

Available on crate feature verifying only.

Given a public key, message digest, and signature, use trial recovery to determine if a suitable recovery ID exists, or return an error otherwise.

pub fn trial_recovery_from_prehash<C>(
    verifying_key: &VerifyingKey<C>,
    prehash: &[u8],
    signature: &Signature<C>
) -> Result<Self>where
    C: PrimeCurve + ProjectiveArithmetic,
    AffinePoint<C>: DecompressPoint<C> + FromEncodedPoint<C> + ToEncodedPoint<C> + VerifyPrimitive<C>,
    FieldSize<C>: ModulusSize,
    Scalar<C>: Reduce<C::UInt>,
    SignatureSize<C>: ArrayLength<u8>,

Available on crate feature verifying only.

Given a public key, message digest, and signature, use trial recovery to determine if a suitable recovery ID exists, or return an error otherwise.

Trait Implementations

impl Clone for RecoveryId

fn clone(&self) -> RecoveryId

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for RecoveryId

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

Formats the value using the given formatter.

impl From<RecoveryId> for u8

fn from(id: RecoveryId) -> u8

Converts to this type from the input type.

impl Ord for RecoveryId

fn cmp(&self, other: &RecoveryId) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Selfwhere
    Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Selfwhere
    Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Selfwhere
    Self: Sized + PartialOrd<Self>,

Restrict a value to a certain interval.

impl PartialEq<RecoveryId> for RecoveryId

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd<RecoveryId> for RecoveryId

fn partial_cmp(&self, other: &RecoveryId) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl TryFrom<u8> for RecoveryId

type Error = Error

The type returned in the event of a conversion error.

fn try_from(byte: u8) -> Result<Self>

Performs the conversion.

impl Copy for RecoveryId

impl Eq for RecoveryId

impl StructuralEq for RecoveryId

impl StructuralPartialEq for RecoveryId