From 138a34ea26362bede345dbaf2523b44c37252b2c Mon Sep 17 00:00:00 2001
From: Amaury <1293565+amaurym@users.noreply.github.com>
Date: Mon, 16 Jan 2023 15:57:47 +0100
Subject: [PATCH] feat!: Add SIGN_MODE_TEXTUAL (#39)

---
 CHANGELOG.md     |  7 +++++++
 user_app.go      | 19 ++++++++++++-------
 user_app_test.go |  4 ++--
 3 files changed, 21 insertions(+), 9 deletions(-)
 create mode 100644 CHANGELOG.md

diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..539e6d7
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,7 @@
+# CHANGELOG
+
+## Unreleased
+
+### API-Breaking Changes
+
+* [#39](https://github.com/cosmos/ledger-cosmos-go/pull/39) Add support for SIGN_MODE_TEXTUAL by adding a new argument `p2 byte` to `SignSECP256K1`.
diff --git a/user_app.go b/user_app.go
index 63b33cc..32f596e 100644
--- a/user_app.go
+++ b/user_app.go
@@ -20,7 +20,7 @@ import (
 	"errors"
 	"math"
 
-	"github.com/zondax/ledger-go"
+	ledger_go "github.com/zondax/ledger-go"
 )
 
 const (
@@ -114,14 +114,15 @@ func (ledger *LedgerCosmos) GetVersion() (*VersionInfo, error) {
 	return &ledger.version, nil
 }
 
-// SignSECP256K1 signs a transaction using Cosmos user app
+// SignSECP256K1 signs a transaction using Cosmos user app. It can either use
+// SIGN_MODE_LEGACY_AMINO_JSON (P2=0) or SIGN_MODE_TEXTUAL (P2=1).
 // this command requires user confirmation in the device
-func (ledger *LedgerCosmos) SignSECP256K1(bip32Path []uint32, transaction []byte) ([]byte, error) {
+func (ledger *LedgerCosmos) SignSECP256K1(bip32Path []uint32, transaction []byte, p2 byte) ([]byte, error) {
 	switch ledger.version.Major {
 	case 1:
 		return ledger.signv1(bip32Path, transaction)
 	case 2:
-		return ledger.signv2(bip32Path, transaction)
+		return ledger.signv2(bip32Path, transaction, p2)
 	default:
 		return nil, errors.New("App version is not supported")
 	}
@@ -220,7 +221,7 @@ func (ledger *LedgerCosmos) signv1(bip32Path []uint32, transaction []byte) ([]by
 	return finalResponse, nil
 }
 
-func (ledger *LedgerCosmos) signv2(bip32Path []uint32, transaction []byte) ([]byte, error) {
+func (ledger *LedgerCosmos) signv2(bip32Path []uint32, transaction []byte, p2 byte) ([]byte, error) {
 	var packetIndex byte = 1
 	var packetCount = 1 + byte(math.Ceil(float64(len(transaction))/float64(userMessageChunkSize)))
 
@@ -228,6 +229,10 @@ func (ledger *LedgerCosmos) signv2(bip32Path []uint32, transaction []byte) ([]by
 
 	var message []byte
 
+	if p2 > 1 {
+		return nil, errors.New("only values of SIGN_MODE_LEGACY_AMINO (P2=0) and SIGN_MODE_TEXTUAL (P2=1) are allowed")
+	}
+
 	for packetIndex <= packetCount {
 		chunk := userMessageChunkSize
 		if packetIndex == 1 {
@@ -235,7 +240,7 @@ func (ledger *LedgerCosmos) signv2(bip32Path []uint32, transaction []byte) ([]by
 			if err != nil {
 				return nil, err
 			}
-			header := []byte{userCLA, userINSSignSECP256K1, 0, 0, byte(len(pathBytes))}
+			header := []byte{userCLA, userINSSignSECP256K1, 0, p2, byte(len(pathBytes))}
 			message = append(header, pathBytes...)
 		} else {
 			if len(transaction) < userMessageChunkSize {
@@ -247,7 +252,7 @@ func (ledger *LedgerCosmos) signv2(bip32Path []uint32, transaction []byte) ([]by
 				payloadDesc = byte(2)
 			}
 
-			header := []byte{userCLA, userINSSignSECP256K1, payloadDesc, 0, byte(chunk)}
+			header := []byte{userCLA, userINSSignSECP256K1, payloadDesc, p2, byte(chunk)}
 			message = append(header, transaction[:chunk]...)
 		}
 
diff --git a/user_app_test.go b/user_app_test.go
index 4c3d347..0597c27 100644
--- a/user_app_test.go
+++ b/user_app_test.go
@@ -207,7 +207,7 @@ func Test_UserSign(t *testing.T) {
 	path := []uint32{44, 118, 0, 0, 5}
 
 	message := getDummyTx()
-	signature, err := userApp.SignSECP256K1(path, message)
+	signature, err := userApp.SignSECP256K1(path, message, 0)
 	if err != nil {
 		t.Fatalf("[Sign] Error: %s\n", err.Error())
 	}
@@ -256,7 +256,7 @@ func Test_UserSign_Fails(t *testing.T) {
 	garbage := []byte{65}
 	message = append(garbage, message...)
 
-	_, err = userApp.SignSECP256K1(path, message)
+	_, err = userApp.SignSECP256K1(path, message, 0)
 	assert.Error(t, err)
 	errMessage := err.Error()