/
ecdsa_signature.go
54 lines (47 loc) · 1011 Bytes
/
ecdsa_signature.go
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package blind
import (
"crypto/ecdsa"
"crypto/rand"
"encoding/json"
"math/big"
"golang.org/x/crypto/sha3"
)
type ECDSASignature struct {
R *big.Int
S *big.Int
DataHash []byte
}
func (c *ECDSASignature) Marshall() ([]byte, error) {
return json.Marshal(map[string]interface{}{
"r": c.R,
"s": c.S,
"datahash": c.DataHash,
})
}
func (c *ECDSASignature) Unmarshall(data []byte) error {
var fields struct {
R *big.Int `json:"r"`
S *big.Int `json:"s"`
DataHash []byte `json:"datahash"`
}
err := json.Unmarshal(data, &fields)
if err != nil {
return err
}
c.R = fields.R
c.S = fields.S
c.DataHash = fields.DataHash
return nil
}
func newECDSASignature(data []byte, privateKey *ecdsa.PrivateKey) (*ECDSASignature, error) {
h := sha3.Sum256(data)
r, s, err := ecdsa.Sign(rand.Reader, privateKey, h[:])
if err != nil {
return &ECDSASignature{}, err
}
return &ECDSASignature{
R: r,
S: s,
DataHash: h[:],
}, nil
}