Struct ecdsa::Signature

pub struct Signature<C: Curve + CheckSignatureBytes> where
    SignatureSize<C>: ArrayLength<u8>,  { /* fields omitted */ }

ECDSA signatures (fixed-size).

Generic over elliptic curve types.

These signatures are serialized as fixed-sized big endian scalar values with no additional 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 is also supported via the Signature::from_asn1 and Signature::to_asn1 methods.

Implementations

impl<C> Signature<C> where
    C: Curve + CheckSignatureBytes,
    SignatureSize<C>: ArrayLength<u8>, 

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

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

pub fn from_asn1(bytes: &[u8]) -> Result<Self, Error> where
    C::FieldSize: Add + ArrayLength<u8>,
    MaxSize<C>: ArrayLength<u8>,
    <C::FieldSize as Add>::Output: Add<MaxOverhead> + ArrayLength<u8>, 

Parse a signature from ASN.1 DER

pub fn to_asn1(&self) -> Signature<C> where
    C::FieldSize: Add + ArrayLength<u8>,
    MaxSize<C>: ArrayLength<u8>,
    <C::FieldSize as Add>::Output: Add<MaxOverhead> + ArrayLength<u8>, 

Serialize this signature as ASN.1 DER

impl<C> Signature<C> where
    C: Curve + ProjectiveArithmetic,
    Scalar<C>: PrimeField<Repr = FieldBytes<C>>,
    <Scalar<C> as PrimeField>::Repr: From<Scalar<C>> + for<'a> From<&'a Scalar<C>>,
    SignatureSize<C>: ArrayLength<u8>, 

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

This is supported on crate feature arithmetic only.

Get the r component of this signature

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

This is supported on crate feature arithmetic only.

Get the s component of this signature

pub fn normalize_s(&mut self) -> Result<bool, Error> where
    Scalar<C>: NormalizeLow, 

This is supported 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: Curve + CheckSignatureBytes,
    SignatureSize<C>: ArrayLength<u8>, 

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

Performs the conversion.

impl<C: Clone + Curve + CheckSignatureBytes> Clone for Signature<C> where
    SignatureSize<C>: ArrayLength<u8>, 

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<C> Copy for Signature<C> where
    C: Curve + CheckSignatureBytes,
    SignatureSize<C>: ArrayLength<u8>,
    <SignatureSize<C> as ArrayLength<u8>>::ArrayType: Copy, 

impl<C> Debug for Signature<C> where
    C: Curve + CheckSignatureBytes,
    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: Curve + ProjectiveArithmetic,
    FieldBytes<C>: From<Scalar<C>> + for<'r> From<&'r Scalar<C>>,
    Scalar<C>: PrimeField<Repr = FieldBytes<C>> + FromDigest<C> + Invert<Output = Scalar<C>> + SignPrimitive<C> + Zeroize,
    D: FixedOutput<OutputSize = C::FieldSize> + BlockInput + Clone + Default + Reset + Update,
    SignatureSize<C>: ArrayLength<u8>, 

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

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 VerifyKey<C> where
    C: Curve + ProjectiveArithmetic,
    D: Digest<OutputSize = C::FieldSize>,
    FieldBytes<C>: From<Scalar<C>> + for<'r> From<&'r Scalar<C>>,
    Scalar<C>: PrimeField<Repr = FieldBytes<C>> + FromDigest<C>,
    AffinePoint<C>: Clone + Debug + VerifyPrimitive<C>,
    SignatureSize<C>: ArrayLength<u8>, 

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

Verify the signature against the given Digest output.

impl<C: Eq + Curve + CheckSignatureBytes> Eq for Signature<C> where
    SignatureSize<C>: ArrayLength<u8>, 

impl<C: PartialEq + Curve + CheckSignatureBytes> PartialEq<Signature<C>> for Signature<C> where
    SignatureSize<C>: ArrayLength<u8>, 

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

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

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

This method tests for !=.

impl<C> PrehashSignature for Signature<C> where
    C: DigestPrimitive + CheckSignatureBytes,
    <C::FieldSize as Add>::Output: ArrayLength<u8>, 

type Digest = C::Digest

Preferred Digest algorithm to use when computing this signature type.

impl<C, D> RandomizedDigestSigner<D, Signature<C>> for SigningKey<C> where
    C: Curve + ProjectiveArithmetic,
    FieldBytes<C>: From<Scalar<C>> + for<'r> From<&'r Scalar<C>>,
    Scalar<C>: PrimeField<Repr = FieldBytes<C>> + FromDigest<C> + Invert<Output = Scalar<C>> + SignPrimitive<C> + Zeroize,
    D: FixedOutput<OutputSize = C::FieldSize> + BlockInput + Clone + Default + Reset + Update,
    SignatureSize<C>: ArrayLength<u8>, 

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

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 RngCore + CryptoRng, digest: D) -> S

Sign the given prehashed message Digest, returning a signature.

impl<C> RandomizedSigner<Signature<C>> for SigningKey<C> where
    C: Curve + ProjectiveArithmetic + DigestPrimitive,
    FieldBytes<C>: From<Scalar<C>> + for<'r> From<&'r Scalar<C>>,
    Scalar<C>: PrimeField<Repr = FieldBytes<C>> + FromDigest<C> + Invert<Output = Scalar<C>> + SignPrimitive<C> + Zeroize,
    SignatureSize<C>: ArrayLength<u8>,
    Self: RandomizedDigestSigner<C::Digest, Signature<C>>, 

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

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 RngCore + CryptoRng, msg: &[u8]) -> S

Sign the given message and return a digital signature

impl<C> Signature for Signature<C> where
    C: Curve + CheckSignatureBytes,
    SignatureSize<C>: ArrayLength<u8>, 

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

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
    C: Curve + ProjectiveArithmetic + DigestPrimitive,
    FieldBytes<C>: From<Scalar<C>> + for<'r> From<&'r Scalar<C>>,
    Scalar<C>: PrimeField<Repr = FieldBytes<C>> + FromDigest<C> + Invert<Output = Scalar<C>> + SignPrimitive<C> + Zeroize,
    SignatureSize<C>: ArrayLength<u8>,
    Self: DigestSigner<C::Digest, Signature<C>>, 

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

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: Curve + CheckSignatureBytes> StructuralEq for Signature<C> where
    SignatureSize<C>: ArrayLength<u8>, 

impl<C: Curve + CheckSignatureBytes> StructuralPartialEq for Signature<C> where
    SignatureSize<C>: ArrayLength<u8>, 

impl<C, '_> TryFrom<&'_ [u8]> for Signature<C> where
    C: Curve + CheckSignatureBytes,
    SignatureSize<C>: ArrayLength<u8>, 

type Error = Error

The type returned in the event of a conversion error.

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

Performs the conversion.

impl<C> TryFrom<Signature<C>> for Signature<C> where
    C: Curve + CheckSignatureBytes,
    C::FieldSize: Add + ArrayLength<u8>,
    MaxSize<C>: ArrayLength<u8>,
    <C::FieldSize as Add>::Output: Add<MaxOverhead> + ArrayLength<u8>, 

type Error = Error

The type returned in the event of a conversion error.

fn try_from(doc: Signature<C>) -> Result<Signature<C>, Error>

Performs the conversion.

impl<C> Verifier<Signature<C>> for VerifyKey<C> where
    C: Curve + ProjectiveArithmetic + DigestPrimitive,
    C::Digest: Digest<OutputSize = C::FieldSize>,
    FieldBytes<C>: From<Scalar<C>> + for<'r> From<&'r Scalar<C>>,
    Scalar<C>: PrimeField<Repr = FieldBytes<C>> + FromDigest<C>,
    AffinePoint<C>: Clone + Debug + VerifyPrimitive<C>,
    SignatureSize<C>: ArrayLength<u8>, 

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

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