Struct Signature

pub struct Signature<C: PrimeCurve>
where
    SignatureSize<C>: ArrayLength<u8>,
{ /* private fields */ }

ECDSA signature (fixed-size). Generic over elliptic curve types.

Serialized as fixed-sized big endian scalar values with no added framing:

• r: field element size for the given curve, big-endian
• s: field element size for the given curve, big-endian

For example, in a curve with a 256-bit modulus like NIST P-256 or secp256k1, r and s will both be 32-bytes, resulting in a signature with a total of 64-bytes.

ASN.1 DER-encoded signatures also supported via the Signature::from_der and Signature::to_der methods.

Implementations

impl<C> Signature<C>

where C: PrimeCurve, SignatureSize<C>: ArrayLength<u8>,

pub fn from_der(bytes: &[u8]) -> Result<Self>

where MaxSize<C>: ArrayLength<u8>, <FieldSize<C> as Add>::Output: Add<MaxOverhead> + ArrayLength<u8>,

Available on crate feature der only.

Parse a signature from ASN.1 DER

pub fn from_scalars( r: impl Into<FieldBytes<C>>, s: impl Into<FieldBytes<C>>, ) -> Result<Self>

Create a Signature from the serialized r and s scalar values which comprise the signature.

pub fn split_bytes(&self) -> (FieldBytes<C>, FieldBytes<C>)

Split the signature into its r and s components, represented as bytes.

pub fn to_der(&self) -> Signature<C>

where MaxSize<C>: ArrayLength<u8>, <FieldSize<C> as Add>::Output: Add<MaxOverhead> + ArrayLength<u8>,

Available on crate feature der only.

Serialize this signature as ASN.1 DER

impl<C> Signature<C>

where C: PrimeCurve + ProjectiveArithmetic, SignatureSize<C>: ArrayLength<u8>,

pub fn r(&self) -> NonZeroScalar<C>

Available on crate feature arithmetic only.

Get the r component of this signature

pub fn s(&self) -> NonZeroScalar<C>

Available on crate feature arithmetic only.

Get the s component of this signature

pub fn split_scalars(&self) -> (NonZeroScalar<C>, NonZeroScalar<C>)

Available on crate feature arithmetic only.

Split the signature into its r and s scalars.

pub fn normalize_s(&self) -> Option<Self>

where Scalar<C>: NormalizeLow,

Available on crate feature arithmetic only.

Normalize signature into “low S” form as described in BIP 0062: Dealing with Malleability.

Trait Implementations

impl<C> AsRef<[u8]> for Signature<C>

where C: PrimeCurve, SignatureSize<C>: ArrayLength<u8>,

fn as_ref(&self) -> &[u8]

Converts this type into a shared reference of the (usually inferred) input type.

impl<C: Clone + PrimeCurve> Clone for Signature<C>

where SignatureSize<C>: ArrayLength<u8>,

fn clone(&self) -> Signature<C>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<C> Debug for Signature<C>

where C: PrimeCurve, SignatureSize<C>: ArrayLength<u8>,

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

Formats the value using the given formatter.

impl<C, D> DigestSigner<D, Signature<C>> for SigningKey<C>

where C: PrimeCurve + ProjectiveArithmetic, D: FixedOutput<OutputSize = FieldSize<C>> + BlockInput + Clone + Default + Reset + Update, Scalar<C>: FromDigest<C> + Invert<Output = Scalar<C>> + SignPrimitive<C>, SignatureSize<C>: ArrayLength<u8>,

fn try_sign_digest(&self, digest: D) -> Result<Signature<C>>

Sign message prehash using a deterministic ephemeral scalar (k) computed using the algorithm described in RFC 6979 (Section 3.2): https://tools.ietf.org/html/rfc6979#section-3

fn sign_digest(&self, digest: D) -> S

Sign the given prehashed message Digest, returning a signature.

impl<C, D> DigestVerifier<D, Signature<C>> for VerifyingKey<C>

where C: PrimeCurve + ProjectiveArithmetic, D: Digest<OutputSize = FieldSize<C>>, AffinePoint<C>: VerifyPrimitive<C>, Scalar<C>: FromDigest<C>, SignatureSize<C>: ArrayLength<u8>,

fn verify_digest(&self, digest: D, signature: &Signature<C>) -> Result<()>

Verify the signature against the given Digest output.

impl<C: PartialEq + PrimeCurve> PartialEq for Signature<C>

where SignatureSize<C>: ArrayLength<u8>,

fn eq(&self, other: &Signature<C>) -> bool

Tests for self and other values to be equal, and is used by ==.

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

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

impl<C> PrehashSignature for Signature<C>

where C: DigestPrimitive, <FieldSize<C> as Add>::Output: ArrayLength<u8>,

Available on crate feature hazmat only.

type Digest = <C as DigestPrimitive>::Digest

Preferred Digest algorithm to use when computing this signature type.

impl<C, D> RandomizedDigestSigner<D, Signature<C>> for SigningKey<C>

where C: PrimeCurve + ProjectiveArithmetic, D: FixedOutput<OutputSize = FieldSize<C>> + BlockInput + Clone + Default + Reset + Update, Scalar<C>: FromDigest<C> + Invert<Output = Scalar<C>> + SignPrimitive<C>, SignatureSize<C>: ArrayLength<u8>,

fn try_sign_digest_with_rng( &self, rng: impl CryptoRng + RngCore, digest: D, ) -> Result<Signature<C>>

Sign message prehash using an ephemeral scalar (k) derived according to a variant of RFC 6979 (Section 3.6) which supplies additional entropy from an RNG.

fn sign_digest_with_rng(&self, rng: impl CryptoRng + RngCore, digest: D) -> S

Sign the given prehashed message Digest, returning a signature.

impl<C> RandomizedSigner<Signature<C>> for SigningKey<C>

where Self: RandomizedDigestSigner<C::Digest, Signature<C>>, C: PrimeCurve + ProjectiveArithmetic + DigestPrimitive, Scalar<C>: FromDigest<C> + Invert<Output = Scalar<C>> + SignPrimitive<C>, SignatureSize<C>: ArrayLength<u8>,

fn try_sign_with_rng( &self, rng: impl CryptoRng + RngCore, msg: &[u8], ) -> Result<Signature<C>>

Attempt to sign the given message, returning a digital signature on success, or an error if something went wrong.

fn sign_with_rng(&self, rng: impl CryptoRng + RngCore, msg: &[u8]) -> S

Sign the given message and return a digital signature

impl<C> Signature for Signature<C>

where C: PrimeCurve, SignatureSize<C>: ArrayLength<u8>,

fn from_bytes(bytes: &[u8]) -> Result<Self>

Parse a signature from its byte representation

fn as_bytes(&self) -> &[u8]

Borrow a byte slice representing the serialized form of this signature

impl<C> Signer<Signature<C>> for SigningKey<C>

where Self: DigestSigner<C::Digest, Signature<C>>, C: PrimeCurve + ProjectiveArithmetic + DigestPrimitive, Scalar<C>: FromDigest<C> + Invert<Output = Scalar<C>> + SignPrimitive<C>, SignatureSize<C>: ArrayLength<u8>,

fn try_sign(&self, msg: &[u8]) -> Result<Signature<C>>

Attempt to sign the given message, returning a digital signature on success, or an error if something went wrong.

fn sign(&self, msg: &[u8]) -> S

Sign the given message and return a digital signature

impl<C> TryFrom<&[u8]> for Signature<C>

where C: PrimeCurve, SignatureSize<C>: ArrayLength<u8>,

type Error = Error

The type returned in the event of a conversion error.

fn try_from(bytes: &[u8]) -> Result<Self>

Performs the conversion.

impl<C> TryFrom<Signature<C>> for Signature<C>

where C: PrimeCurve, MaxSize<C>: ArrayLength<u8>, <FieldSize<C> as Add>::Output: Add<MaxOverhead> + ArrayLength<u8>,

Available on crate feature der only.

type Error = Error

The type returned in the event of a conversion error.

fn try_from(sig: Signature<C>) -> Result<Signature<C>>

Performs the conversion.

impl<C> Verifier<Signature<C>> for VerifyingKey<C>

where C: PrimeCurve + ProjectiveArithmetic + DigestPrimitive, C::Digest: Digest<OutputSize = FieldSize<C>>, AffinePoint<C>: VerifyPrimitive<C>, Scalar<C>: FromDigest<C>, SignatureSize<C>: ArrayLength<u8>,

fn verify(&self, msg: &[u8], signature: &Signature<C>) -> Result<()>

Use Self to verify that the provided signature for a given message bytestring is authentic.

impl<C> Copy for Signature<C>

where C: PrimeCurve, SignatureSize<C>: ArrayLength<u8>, <SignatureSize<C> as ArrayLength<u8>>::ArrayType: Copy,

impl<C: Eq + PrimeCurve> Eq for Signature<C>

where SignatureSize<C>: ArrayLength<u8>,

impl<C: PrimeCurve> StructuralPartialEq for Signature<C>

where SignatureSize<C>: ArrayLength<u8>,