From 642975c87c35e256d57c01b9ee6ecf827c06cbfa Mon Sep 17 00:00:00 2001
From: Antonio Pitasi <antonio@pitasi.dev>
Date: Mon, 9 Sep 2024 10:16:11 +0200
Subject: [PATCH] fix(go-client): use ethsecp256k1 instead of cosmos'

This fixes the derivation of a seed phrase into a private key.

It also makes the derivation path non-configurable, since it only makes
sense when used with the Ethereum derivation path.
---
 go-client/tx_identity.go      | 10 ++++++----
 go-client/tx_identity_test.go | 23 +++++++++++++++++++++++
 2 files changed, 29 insertions(+), 4 deletions(-)
 create mode 100644 go-client/tx_identity_test.go

diff --git a/go-client/tx_identity.go b/go-client/tx_identity.go
index f4d0ef0a0..77767fedf 100644
--- a/go-client/tx_identity.go
+++ b/go-client/tx_identity.go
@@ -5,12 +5,14 @@ import (
 
 	"github.com/btcsuite/btcd/btcec/v2"
 	"github.com/cosmos/cosmos-sdk/crypto/hd"
-	"github.com/cosmos/cosmos-sdk/crypto/keys/secp256k1"
 	cryptotypes "github.com/cosmos/cosmos-sdk/crypto/types"
 	sdktypes "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/go-bip39"
+	"github.com/evmos/evmos/v18/crypto/ethsecp256k1"
 )
 
+var DefaultDerivationPath = "m/44'/60'/0'/0/0"
+
 // Identity represents an account on the Warden Protocol. It can be used to sign
 // transactions.
 type Identity struct {
@@ -20,7 +22,7 @@ type Identity struct {
 
 // NewIdentityFromSeed returns a Identity from a seed phrase.
 // This is useful in a mock environment or during testing but should not be used in production.
-func NewIdentityFromSeed(derivationPath, seedPhrase string) (Identity, error) {
+func NewIdentityFromSeed(seedPhrase string) (Identity, error) {
 	// Convert the seed phrase to a seed
 	seedBytes, err := bip39.NewSeedWithErrorChecking(seedPhrase, "")
 	if err != nil {
@@ -29,7 +31,7 @@ func NewIdentityFromSeed(derivationPath, seedPhrase string) (Identity, error) {
 
 	// Create a master key and derive the desired key
 	masterKey, ch := hd.ComputeMastersFromSeed(seedBytes)
-	derivedKey, err := hd.DerivePrivateKeyForPath(masterKey, ch, derivationPath)
+	derivedKey, err := hd.DerivePrivateKeyForPath(masterKey, ch, DefaultDerivationPath)
 	if err != nil {
 		return Identity{}, fmt.Errorf("failed to derive private key: %w", err)
 	}
@@ -38,7 +40,7 @@ func NewIdentityFromSeed(derivationPath, seedPhrase string) (Identity, error) {
 	privKey, _ := btcec.PrivKeyFromBytes(derivedKey)
 
 	// Convert the public key to a Cosmos secp256k1.PublicKey
-	cosmosPrivKey := &secp256k1.PrivKey{
+	cosmosPrivKey := &ethsecp256k1.PrivKey{
 		Key: privKey.Serialize(),
 	}
 
diff --git a/go-client/tx_identity_test.go b/go-client/tx_identity_test.go
new file mode 100644
index 000000000..20b19b7ec
--- /dev/null
+++ b/go-client/tx_identity_test.go
@@ -0,0 +1,23 @@
+package client
+
+import (
+	"encoding/base64"
+	"fmt"
+	"testing"
+)
+
+func TestNewIdentityFromSeed(t *testing.T) {
+	seed := "exclude try nephew main caught favorite tone degree lottery device tissue tent ugly mouse pelican gasp lava flush pen river noise remind balcony emerge"
+
+	id, err := NewIdentityFromSeed(seed)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	fmt.Printf("address: %s\n", id.Address.String())
+	fmt.Printf("private key: %s\n", base64.StdEncoding.EncodeToString(id.PrivKey.Bytes()))
+
+	if id.Address.String() != "warden1d652c9nngq5cneak2whyaqa4g9ehr8pstxj0r5" {
+		t.Fatalf("unexpected address: %s", id.Address.String())
+	}
+}