update

app.conf

 [server]
 address = "0.0.0.0:9900"
-privatekey = 0x0aa528c00748fd3fc37f5cb5f995f3da9c820df02aef5cb7786c8ea54abb0950
+privatekey = 0aa528c00748fd3fc37f5cb5f995f3da9c820df02aef5cb7786c8ea54abb0950
 
 [log]
 level = info
-file = service.log
\ No newline at end of file
+file = service.log

service/randomService.go

@@ -8,12 +8,12 @@ import (
 	"gitlab.com/hashrs/randomservice/common"
 )
 
-func RandomService(account []byte, pk string) (map[string]interface{},error) {
-	r,err := rand.Prime(rand.Reader, 128)
+func RandomService(account []byte, pk string) (map[string]interface{}, error) {
+	r, err := rand.Prime(rand.Reader, 128)
 	if err != nil {
 		return nil, errors.New("generate prime failed")
 	}
-	data := common.BytesCombine(account,r.Bytes())
+	data := common.BytesCombine(account, r.Bytes())
 	sig, err := common.Sign(pk, data)
 	if err != nil {
 		return nil, errors.New(fmt.Sprintf("sign failed (%s)", err))
@@ -21,7 +21,7 @@ func RandomService(account []byte, pk string) (map[string]interface{},error) {
 
 	var res = make(map[string]interface{})
 	res["rand"] = r.Text(16)
-	res["signature"] = hex.EncodeToString(sig)
+	res["signature"] = "0x" + hex.EncodeToString(sig)
 
 	return res, nil
 }