Struct Signature 

pub struct Signature<C: EcdsaCurve> {
    pub(crate) r: ScalarValue<C>,
    pub(crate) s: ScalarValue<C>,
}

ECDSA signature (fixed-size, a.k.a. IEEE P1363). 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

Both r and s MUST be non-zero.

For example, in a curve with a 256-bit modulus like NIST P-256 or secp256k1, r and s will both be 32-bytes and serialized as big endian, 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.

serde support

When the serde feature of this crate is enabled, it provides support for serializing and deserializing ECDSA signatures using the Serialize and Deserialize traits.

The serialization uses a hexadecimal encoding when used with “human readable” text formats, and a binary encoding otherwise.

Fields

r: ScalarValue<C>

s: ScalarValue<C>

Implementations

impl<C> Signature<C>

where C: EcdsaCurve, SignatureSize<C>: ArraySize,

pub fn from_bytes(bytes: &SignatureBytes<C>) -> Result<Self>

Parse a signature from fixed-width bytes, i.e. 2 * the size of FieldBytes for a particular curve.

Returns

• Ok(signature) if the r and s components are both in the valid range 1..n when serialized as concatenated big endian integers.
• Err(err) if the r and/or s component of the signature is out-of-range when interpreted as a big endian integer.

pub fn from_slice(slice: &[u8]) -> Result<Self>

Parse a signature from a byte slice.

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

where MaxSize<C>: ArraySize, <FieldBytesSize<C> as Add>::Output: Add<MaxOverhead> + ArraySize,

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.

Returns

• Ok(signature) if the r and s components are both in the valid range 1..n when serialized as concatenated big endian integers.
• Err(err) if the r and/or s component of the signature is out-of-range when interpreted as a big endian integer.

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

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

pub fn to_bytes(&self) -> SignatureBytes<C>

Serialize this signature as bytes.

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

where MaxSize<C>: ArraySize, <FieldBytesSize<C> as Add>::Output: Add<MaxOverhead> + ArraySize,

Serialize this signature as ASN.1 DER.

pub fn to_vec(&self) -> Vec<u8>

Convert this signature into a byte vector.

impl<C> Signature<C>

where C: EcdsaCurve + CurveArithmetic, SignatureSize<C>: ArraySize,

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

Get the r component of this signature

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

Get the s component of this signature

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

Split the signature into its r and s scalars.

pub fn normalize_s(&self) -> Self

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

Trait Implementations

impl<C> AssociatedAlgorithmIdentifier for Signature<C>

where C: EcdsaCurve, Self: AssociatedOid,

Available on crate feature pkcs8 only.

ECDSA AlgorithmIdentifier which identifies the digest used by default with the Signer and Verifier traits.

const ALGORITHM_IDENTIFIER: AlgorithmIdentifierRef<'static>

AlgorithmIdentifier for this structure.

type Params = AnyRef<'static>

Algorithm parameters.

impl<C> AssociatedOid for Signature<C>

where C: DigestAlgorithm, C::Digest: AssociatedOid,

Available on crate features digest and hazmat only.

ECDSA ObjectIdentifier which identifies the digest used by default with the Signer and Verifier traits.

To support non-default digest algorithms, use the SignatureWithOid type instead.

const OID: ObjectIdentifier

The OID associated with this type.

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

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: EcdsaCurve, SignatureSize<C>: ArraySize,

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: EcdsaCurve + CurveArithmetic + DigestAlgorithm, D: Digest + FixedOutput, Scalar<C>: Invert<Output = CtOption<Scalar<C>>>, SignatureSize<C>: ArraySize,

Sign message digest using a deterministic ephemeral scalar (k) computed using the algorithm described in RFC6979 § 3.2.

fn try_sign_digest<F: Fn(&mut D) -> Result<()>>( &self, f: F, ) -> Result<Signature<C>>

Attempt to sign a message by updating the received Digest with it, returning a digital signature on success, or an error if something went wrong.

fn sign_digest<F>(&self, f: F) -> S

where F: Fn(&mut D),

Sign a message by updating the received Digest with it, returning a signature.

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

where C: EcdsaCurve + CurveArithmetic, D: Digest + Update, SignatureSize<C>: ArraySize,

fn verify_digest<F: Fn(&mut D) -> Result<()>>( &self, f: F, signature: &Signature<C>, ) -> Result<()>

Verify the signature against the received Digest output, by updating it with the message.

impl<C> Display for Signature<C>

where C: EcdsaCurve, SignatureSize<C>: ArraySize,

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

Formats the value using the given formatter.

impl<C> From<Signature<C>> for SignatureBytes<C>

where C: EcdsaCurve, SignatureSize<C>: ArraySize,

fn from(signature: Signature<C>) -> SignatureBytes<C>

Converts to this type from the input type.

impl<C> From<Signature<C>> for Signature<C>

where C: EcdsaCurve, MaxSize<C>: ArraySize, <FieldBytesSize<C> as Add>::Output: Add<MaxOverhead> + ArraySize,

fn from(sig: Signature<C>) -> Signature<C>

Converts to this type from the input type.

impl<C> From<SignatureWithOid<C>> for Signature<C>

where C: EcdsaCurve,

Available on crate feature digest only.

fn from(sig: SignatureWithOid<C>) -> Signature<C>

Converts to this type from the input type.

impl<C> FromStr for Signature<C>

where C: EcdsaCurve + CurveArithmetic, SignatureSize<C>: ArraySize,

Available on crate feature algorithm only.

type Err = Error

The associated error which can be returned from parsing.

fn from_str(hex: &str) -> Result<Self>

Parses a string s to return a value of this type.

impl<C> Hash for Signature<C>

where C: EcdsaCurve, SignatureSize<C>: ArraySize,

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<C> LowerHex for Signature<C>

where C: EcdsaCurve, SignatureSize<C>: ArraySize,

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

Formats the value using the given formatter.

impl<C> MultipartSigner<Signature<C>> for SigningKey<C>

where C: EcdsaCurve + CurveArithmetic + DigestAlgorithm, Scalar<C>: Invert<Output = CtOption<Scalar<C>>>, SignatureSize<C>: ArraySize,

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

Equivalent of Signer::try_sign() but the message is provided in non-contiguous byte slices.

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

Equivalent of Signer::sign() but the message is provided in non-contiguous byte slices.

impl<C> MultipartVerifier<Signature<C>> for VerifyingKey<C>

where C: EcdsaCurve + CurveArithmetic + DigestAlgorithm, SignatureSize<C>: ArraySize,

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

Equivalent of Verifier::verify() but the message is provided in non-contiguous byte slices.

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

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> PrehashSigner<Signature<C>> for SigningKey<C>

where C: EcdsaCurve + CurveArithmetic + DigestAlgorithm, Scalar<C>: Invert<Output = CtOption<Scalar<C>>>, SignatureSize<C>: ArraySize,

Sign message prehash using a deterministic ephemeral scalar (k) computed using the algorithm described in RFC6979 § 3.2.

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

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

impl<C> PrehashVerifier<Signature<C>> for VerifyingKey<C>

where C: EcdsaCurve + CurveArithmetic, SignatureSize<C>: ArraySize,

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

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

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

where C: EcdsaCurve + CurveArithmetic + DigestAlgorithm, D: Digest + FixedOutput, Scalar<C>: Invert<Output = CtOption<Scalar<C>>>, SignatureSize<C>: ArraySize,

fn try_sign_digest_with_rng<R: TryCryptoRng + ?Sized, F: Fn(&mut D) -> Result<()>>( &self, rng: &mut R, f: F, ) -> Result<Signature<C>>

Attempt to sign a message by updating the received Digest with it, returning a digital signature on success, or an error if something went wrong.

fn sign_digest_with_rng<R, F>(&self, rng: &mut R, f: F) -> S

where R: CryptoRng + ?Sized, F: Fn(&mut D),

Sign a message by updating the received Digest with it, returning a signature.

impl<C> RandomizedMultipartSigner<Signature<C>> for SigningKey<C>

where Self: RandomizedDigestSigner<C::Digest, Signature<C>>, C: EcdsaCurve + CurveArithmetic + DigestAlgorithm, Scalar<C>: Invert<Output = CtOption<Scalar<C>>>, SignatureSize<C>: ArraySize,

fn try_multipart_sign_with_rng<R: TryCryptoRng + ?Sized>( &self, rng: &mut R, msg: &[&[u8]], ) -> Result<Signature<C>>

Equivalent of RandomizedSigner::try_sign_with_rng() but the message is provided in non-contiguous byte slices.

fn multipart_sign_with_rng<R>(&self, rng: &mut R, msg: &[&[u8]]) -> S

where R: CryptoRng + ?Sized,

Equivalent of RandomizedSigner::sign_with_rng() but the message is provided in non-contiguous byte slices.

impl<C> RandomizedPrehashSigner<Signature<C>> for SigningKey<C>

where C: EcdsaCurve + CurveArithmetic + DigestAlgorithm, Scalar<C>: Invert<Output = CtOption<Scalar<C>>>, SignatureSize<C>: ArraySize,

fn sign_prehash_with_rng<R: TryCryptoRng + ?Sized>( &self, rng: &mut R, prehash: &[u8], ) -> Result<Signature<C>>

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

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

where Self: RandomizedDigestSigner<C::Digest, Signature<C>>, C: EcdsaCurve + CurveArithmetic + DigestAlgorithm, Scalar<C>: Invert<Output = CtOption<Scalar<C>>>, SignatureSize<C>: ArraySize,

fn try_sign_with_rng<R: TryCryptoRng + ?Sized>( &self, rng: &mut R, 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<R>(&self, rng: &mut R, msg: &[u8]) -> S

where R: CryptoRng + ?Sized,

Sign the given message and return a digital signature

impl<C> SignatureEncoding for Signature<C>

where C: EcdsaCurve, SignatureSize<C>: ArraySize,

type Repr = Array<u8, <<C as Curve>::FieldBytesSize as Add>::Output>

Byte representation of a signature.

fn to_bytes(&self) -> Self::Repr

Encode signature as its byte representation.

fn to_vec(&self) -> Vec<u8>

Encode signature as a byte vector.

fn encoded_len(&self) -> usize

Get the length of this signature when encoded.

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

where C: EcdsaCurve + CurveArithmetic + DigestAlgorithm, Scalar<C>: Invert<Output = CtOption<Scalar<C>>>, SignatureSize<C>: ArraySize,

Sign message using a deterministic ephemeral scalar (k) computed using the algorithm described in RFC6979 § 3.2.

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: EcdsaCurve, SignatureSize<C>: ArraySize,

type Error = Error

The type returned in the event of a conversion error.

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

Performs the conversion.

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

where C: EcdsaCurve, MaxSize<C>: ArraySize, <FieldBytesSize<C> as Add>::Output: Add<MaxOverhead> + ArraySize,

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> UpperHex for Signature<C>

where C: EcdsaCurve, SignatureSize<C>: ArraySize,

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

Formats the value using the given formatter.

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

where C: EcdsaCurve + CurveArithmetic + DigestAlgorithm, SignatureSize<C>: ArraySize,

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

Use Self (e.g. a verifying key) to verify that the provided signature is authentic for a given message bytestring.

impl<C: EcdsaCurve> Zeroize for Signature<C>

fn zeroize(&mut self)

Zero out this object from memory using Rust intrinsics which ensure the zeroization operation is not “optimized away” by the compiler.

impl<C> Copy for Signature<C>

where C: EcdsaCurve, SignatureSize<C>: ArraySize, <SignatureSize<C> as ArraySize>::ArrayType<u8>: Copy,

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

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