testecdsa.go

package main

import (
	"crypto/ecdsa"
	"crypto/x509"
	"encoding/asn1"
	"encoding/hex"
	"log"
	"math/big"
)

type ecdsaSignature struct {
	R *big.Int
	S *big.Int
}

const signatureHex = "3046022100c71e88ee6dbd43370c2c982031846dd37a764d331e6eb769ef2675d38fa523f40221008db38909f2249279ac50dab8448ee178d46f6b1ef62c4e0c11c9a1ebeaa69966"
const pubKeyHex = "3059301306072a8648ce3d020106082a8648ce3d030107034200047c073a351d218d911ce28d750347388bd355e3dac5de1f93e446fa2f6824d8b54884ceeea81089495bebd6dddfb2023f717a34f065a6a97c83bf6238ec1d714c"

var hash = []byte("\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00")

func main() {
	signatureBytes, err := hex.DecodeString(signatureHex)
	if err != nil {
		log.Panicln(err)
	}
	pubKeyBytes, err := hex.DecodeString(pubKeyHex)
	if err != nil {
		log.Panicln(err)
	}
	ikey, err := x509.ParsePKIXPublicKey(pubKeyBytes)
	if err != nil {
		log.Panicln(err)
	}
	pubKey := ikey.(*ecdsa.PublicKey)
	var sig ecdsaSignature
	_, err = asn1.Unmarshal(signatureBytes, &sig)
	if err != nil {
		log.Panicln(err)
	}
	if ecdsa.Verify(pubKey, hash, sig.R, sig.S) {
		log.Println("Verification succeded")
	} else {
		log.Println("Failed")
	}
}