Struct Signature 

pub struct Signature<C: EcdsaCurve> { /* private fields */ }

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 are both 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.

Implementations

impl<C> Signature<C>

where C: EcdsaCurve,

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.

Errors

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.

Errors

Returns Error in the event the signature is not the expected size, i.e. 2 * the size of FieldBytes for a particular curve.

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

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

Available on crate feature der only.

Parse a signature from ASN.1 DER.

Errors

Returns Error if input failed to parse as an ASN.1 DER-encoded ECDSA signature.

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.

Errors

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,

Available on crate feature der only.

Serialize this signature as ASN.1 DER.

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

Available on crate feature alloc only.

Convert this signature into a byte vector.

impl<C> Signature<C>

where C: EcdsaCurve + CurveArithmetic,

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

Available on crate feature algorithm only.

Get the r component of this signature

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

Available on crate feature algorithm only.

Get the s component of this signature

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

Available on crate feature algorithm only.

Split the signature into its r and s scalars.

pub fn normalize_s(&self) -> Self

Available on crate feature algorithm only.

Normalize signature into “low S” form 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 feature digest 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: Copy + EcdsaCurve> Copy for Signature<C>

impl<C> Debug for Signature<C>

where C: EcdsaCurve,

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

Formats the value using the given formatter.

impl<'de, C> Deserialize<'de> for Signature<C>

where C: EcdsaCurve,

Available on crate feature serde only.

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

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>>>,

Available on crate feature algorithm only.

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,

Available on crate feature algorithm only.

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,

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

Formats the value using the given formatter.

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

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

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

Available on crate feature der only.

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

Converts to this type from the input type.

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

where C: EcdsaCurve,

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

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,

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,

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>>>,

Available on crate feature algorithm only.

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,

Available on crate feature algorithm only.

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>>>,

Available on crate feature algorithm only.

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,

Available on crate feature algorithm only.

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>>>,

Available on crate feature algorithm only.

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>>>,

Available on crate feature algorithm only.

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>>>,

Available on crate feature algorithm only.

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>>>,

Available on crate feature algorithm only.

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> Serialize for Signature<C>

where C: EcdsaCurve,

Available on crate feature serde only.

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl<C> SignatureEncoding for Signature<C>

where C: EcdsaCurve,

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>

Available on crate feature alloc only.

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>>>,

Available on crate feature algorithm only.

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: PartialEq + EcdsaCurve> StructuralPartialEq for Signature<C>

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

where C: EcdsaCurve,

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,

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> UpperHex for Signature<C>

where C: EcdsaCurve,

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,

Available on crate feature algorithm only.

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.