package ecdsa

Import Path
	crypto/ecdsa (on go.dev)

Dependency Relation
	imports 19 packages, and imported by 2 packages


Involved Source Files

	
		Package ecdsa implements the Elliptic Curve Digital Signature Algorithm, as
		defined in FIPS 186-4 and SEC 1, Version 2.0.
		
		Signatures generated by this package are not deterministic, but entropy is
		mixed with the private key and the message, achieving the same level of
		security in case of randomness source failure.

	    ecdsa_legacy.go
	    ecdsa_noasm.go
	    notboring.go


Code Examples

	
		package main
		
		import (
			"crypto/ecdsa"
			"crypto/elliptic"
			"crypto/rand"
			"crypto/sha256"
			"fmt"
		)
		
		func main() {
			privateKey, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
			if err != nil {
				panic(err)
			}
		
			msg := "hello, world"
			hash := sha256.Sum256([]byte(msg))
		
			sig, err := ecdsa.SignASN1(rand.Reader, privateKey, hash[:])
			if err != nil {
				panic(err)
			}
			fmt.Printf("signature: %x\n", sig)
		
			valid := ecdsa.VerifyASN1(&privateKey.PublicKey, hash[:], sig)
			fmt.Println("signature verified:", valid)
		}




Package-Level Type Names (total 2)


	/* sort by:  |  */
	
		PrivateKey represents an ECDSA private key.

		
			D *big.Int
			PublicKey PublicKey
			PublicKey.Curve elliptic.Curve
			PublicKey.X *big.Int
			PublicKey.Y *big.Int
		
			
				Add returns the sum of (x1,y1) and (x2,y2).
				
				Deprecated: this is a low-level unsafe API.

			
				Double returns 2*(x,y).
				
				Deprecated: this is a low-level unsafe API.

			
				ECDH returns k as a [ecdh.PrivateKey]. It returns an error if the key is
				invalid according to the definition of [ecdh.Curve.NewPrivateKey], or if the
				Curve is not supported by [crypto/ecdh].

			
				Equal reports whether priv and x have the same value.
				
				See [PublicKey.Equal] for details on how Curve is compared.

			
				IsOnCurve reports whether the given (x,y) lies on the curve.
				
				Deprecated: this is a low-level unsafe API. For ECDH, use the crypto/ecdh
				package. The NewPublicKey methods of NIST curves in crypto/ecdh accept
				the same encoding as the Unmarshal function, and perform on-curve checks.

			
				Params returns the parameters for the curve.

			
				Public returns the public key corresponding to priv.

			
				ScalarBaseMult returns k*G, where G is the base point of the group
				and k is an integer in big-endian form.
				
				Deprecated: this is a low-level unsafe API. For ECDH, use the crypto/ecdh
				package. Most uses of ScalarBaseMult can be replaced by a call to the
				PrivateKey.PublicKey method in crypto/ecdh.

			
				ScalarMult returns k*(x,y) where k is an integer in big-endian form.
				
				Deprecated: this is a low-level unsafe API. For ECDH, use the crypto/ecdh
				package. Most uses of ScalarMult can be replaced by a call to the ECDH
				methods of NIST curves in crypto/ecdh.

			
				Sign signs digest with priv, reading randomness from rand. The opts argument
				is not currently used but, in keeping with the crypto.Signer interface,
				should be the hash function used to digest the message.
				
				This method implements crypto.Signer, which is an interface to support keys
				where the private part is kept in, for example, a hardware module. Common
				uses can use the [SignASN1] function in this package directly.

		
			*PrivateKey : crypto.Signer
			 PrivateKey : crypto/elliptic.Curve
		
			func GenerateKey(c elliptic.Curve, rand io.Reader) (*PrivateKey, error)
			func crypto/x509.ParseECPrivateKey(der []byte) (*PrivateKey, error)
		
			func Sign(rand io.Reader, priv *PrivateKey, hash []byte) (r, s *big.Int, err error)
			func SignASN1(rand io.Reader, priv *PrivateKey, hash []byte) ([]byte, error)
			func crypto/x509.MarshalECPrivateKey(key *PrivateKey) ([]byte, error)


	
		PublicKey represents an ECDSA public key.

		
			Curve elliptic.Curve
			X *big.Int
			Y *big.Int
		
			
				Add returns the sum of (x1,y1) and (x2,y2).
				
				Deprecated: this is a low-level unsafe API.

			
				Double returns 2*(x,y).
				
				Deprecated: this is a low-level unsafe API.

			
				ECDH returns k as a [ecdh.PublicKey]. It returns an error if the key is
				invalid according to the definition of [ecdh.Curve.NewPublicKey], or if the
				Curve is not supported by crypto/ecdh.

			
				Equal reports whether pub and x have the same value.
				
				Two keys are only considered to have the same value if they have the same Curve value.
				Note that for example [elliptic.P256] and elliptic.P256().Params() are different
				values, as the latter is a generic not constant time implementation.

			
				IsOnCurve reports whether the given (x,y) lies on the curve.
				
				Deprecated: this is a low-level unsafe API. For ECDH, use the crypto/ecdh
				package. The NewPublicKey methods of NIST curves in crypto/ecdh accept
				the same encoding as the Unmarshal function, and perform on-curve checks.

			
				Params returns the parameters for the curve.

			
				ScalarBaseMult returns k*G, where G is the base point of the group
				and k is an integer in big-endian form.
				
				Deprecated: this is a low-level unsafe API. For ECDH, use the crypto/ecdh
				package. Most uses of ScalarBaseMult can be replaced by a call to the
				PrivateKey.PublicKey method in crypto/ecdh.

			
				ScalarMult returns k*(x,y) where k is an integer in big-endian form.
				
				Deprecated: this is a low-level unsafe API. For ECDH, use the crypto/ecdh
				package. Most uses of ScalarMult can be replaced by a call to the ECDH
				methods of NIST curves in crypto/ecdh.

		
			 PublicKey : crypto/elliptic.Curve
		
			func Verify(pub *PublicKey, hash []byte, r, s *big.Int) bool
			func VerifyASN1(pub *PublicKey, hash, sig []byte) bool




Package-Level Functions (total 5)


	
		GenerateKey generates a new ECDSA private key for the specified curve.
		
		Most applications should use [crypto/rand.Reader] as rand. Note that the
		returned key does not depend deterministically on the bytes read from rand,
		and may change between calls and/or between versions.


	
		Sign signs a hash (which should be the result of hashing a larger message)
		using the private key, priv. If the hash is longer than the bit-length of the
		private key's curve order, the hash will be truncated to that length. It
		returns the signature as a pair of integers. Most applications should use
		[SignASN1] instead of dealing directly with r, s.


	
		SignASN1 signs a hash (which should be the result of hashing a larger message)
		using the private key, priv. If the hash is longer than the bit-length of the
		private key's curve order, the hash will be truncated to that length. It
		returns the ASN.1 encoded signature.
		
		The signature is randomized. Most applications should use [crypto/rand.Reader]
		as rand. Note that the returned signature does not depend deterministically on
		the bytes read from rand, and may change between calls and/or between versions.


	
		Verify verifies the signature in r, s of hash using the public key, pub. Its
		return value records whether the signature is valid. Most applications should
		use VerifyASN1 instead of dealing directly with r, s.


	
		VerifyASN1 verifies the ASN.1 encoded signature, sig, of hash using the
		public key, pub. Its return value records whether the signature is valid.