Documentation
¶
Overview ¶
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.
Example ¶
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)
}
Output:
Index ¶
- 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 Verify(pub *PublicKey, hash []byte, r, s *big.Int) bool
- func VerifyASN1(pub *PublicKey, hash, sig []byte) bool
- type PrivateKey
- type PublicKey
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Sign ¶
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.
func SignASN1 ¶
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.
func Verify ¶
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.
func VerifyASN1 ¶
VerifyASN1 verifies the ASN.1 encoded signature, sig, of hash using the public key, pub. Its return value records whether the signature is valid.
Types ¶
type PrivateKey ¶
PrivateKey represents an ECDSA private key.
func GenerateKey ¶
GenerateKey generates a public and private key pair.
func (*PrivateKey) Equal ¶
func (priv *PrivateKey) Equal(x crypto.PrivateKey) bool
Equal reports whether priv and x have the same value.
See PublicKey.Equal for details on how Curve is compared.
func (*PrivateKey) Public ¶
func (priv *PrivateKey) Public() crypto.PublicKey
Public returns the public key corresponding to priv.
func (*PrivateKey) Sign ¶
func (priv *PrivateKey) Sign(rand io.Reader, digest []byte, opts crypto.SignerOpts) ([]byte, error)
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.
type PublicKey ¶
PublicKey represents an ECDSA public key.
func (*PublicKey) Equal ¶
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.
Source Files