From 1cd37fcde7e9497ed703af46f7067e771cfbfc09 Mon Sep 17 00:00:00 2001
From: Tilen Marc <tilen.marc@abelium.com>
Date: Tue, 11 Jun 2024 11:51:22 +0200
Subject: [PATCH] Changing signature encoding.

---
 go-client/README.md        |  5 +++--
 go-client/keygen/keygen.go | 26 +++++++++++++++++++-------
 2 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/go-client/README.md b/go-client/README.md
index ae624c7..8020ee6 100644
--- a/go-client/README.md
+++ b/go-client/README.md
@@ -155,8 +155,9 @@ to be replaced by the actual address that will be used to sign the updates.
 Alternatively, one can save and read the (encrypted) key from a file and save the signature with:
 
 ```bash
-go run keygen/keygen.go --key_out keys.out --pass secret_password
-go run keygen/keygen.go --key_file keys.out --pass secret_password --address 0xd4e934C2749CA8C1618659D02E7B28B074bf4df7 --sig_out sig.out
+go run keygen/keygen.go --key_out keys.out --pass secret_password # generate and save a key to file
+go run keygen/keygen.go --key_file keys.out --pass secret_password --address 0xd4e934C2749CA8C1618659D02E7B28B074bf4df7 --sig_out sig.out # read and decrypt a key from a file, sign and write the signature to a file
+go run keygen/keygen.go --key_file keys.out --pass secret_password # read and decrypt a key from file, just print it out
 ```
 
 where the address value needs to be replaced by the actual address that will be used to sign
diff --git a/go-client/keygen/keygen.go b/go-client/keygen/keygen.go
index 1ce6e9e..5854b12 100644
--- a/go-client/keygen/keygen.go
+++ b/go-client/keygen/keygen.go
@@ -18,6 +18,7 @@ import (
 
 	"github.com/consensys/gnark-crypto/ecc/bn254"
 	"github.com/consensys/gnark-crypto/ecc/bn254/fp"
+	"github.com/ethereum/go-ethereum/accounts/abi"
 	"golang.org/x/crypto/scrypt"
 )
 
@@ -27,6 +28,7 @@ var InFileFlag = flag.String("key_file", "", "File to load private and public ke
 var KeyOutFlag = flag.String("key_out", "", "File to save a freshly generated private and public key")
 var PassFlag = flag.String("pass", "", "Password for encrypting/decrypting private key")
 var SigOutFlag = flag.String("sig_out", "", "File to save a signature")
+var uint256Ty, _ = abi.NewType("uint256", "uint256", nil)
 
 type keyStrings struct {
 	PublicKeyX string
@@ -41,9 +43,7 @@ type keyEncrypted struct {
 }
 
 type sigStrings struct {
-	RX string
-	RY string
-	S  string
+	Signature string
 }
 
 func main() {
@@ -170,21 +170,33 @@ func main() {
 		if err != nil {
 			log.Fatal(err)
 		}
-		sigStrings := sigStrings{S: "0x" + signature.S.Text(16), RX: "0x" + signature.R.X.Text(16), RY: "0x" + signature.R.Y.Text(16)}
-		sigBytes, err := json.Marshal(sigStrings)
+
+		arguments := abi.Arguments{
+			{Type: uint256Ty}, {Type: uint256Ty}, {Type: uint256Ty},
+		}
+		sigBytes, err := arguments.Pack(
+			signature.S,
+			signature.R.X.BigInt(new(big.Int)),
+			signature.R.Y.BigInt(new(big.Int)),
+		)
 		if err != nil {
 			log.Fatal(err)
 		}
 
 		if *SigOutFlag == "" {
-			logger.Info("Signature generated: " + string(sigBytes))
+			logger.Info("Signature generated: 0x" + hex.EncodeToString(sigBytes))
 		} else {
 			f, err := os.Create(*SigOutFlag)
 			if err != nil {
 				log.Fatal(err)
 			}
 
-			_, err = f.Write(sigBytes)
+			sigStruct := sigStrings{Signature: "0x" + hex.EncodeToString(sigBytes)}
+			sigToWrite, err := json.Marshal(sigStruct)
+			if err != nil {
+				log.Fatal(err)
+			}
+			_, err = f.Write(sigToWrite)
 			if err != nil {
 				log.Fatal(err)
 			}