IBC amino for MsgTransfer only, credit: @fedekunze

CHANGELOG.md

@@ -36,6 +36,10 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ## [Unreleased]
 
+### State Machine Breaking
+
+* (x/ibc) [\#8266](https://github.com/cosmos/cosmos-sdk/issues/8266) Add amino JSON for IBC messages in order to support Ledger text signing.
+
 ### Improvements
 
 * (x/ibc) [\#8404](https://github.com/cosmos/cosmos-sdk/pull/8404) Reorder IBC `ChanOpenAck` and `ChanOpenConfirm` handler execution to perform core handler first, followed by application callbacks.

x/auth/client/rest/rest_test.go

@@ -186,8 +186,7 @@ func (s *IntegrationTestSuite) TestBroadcastIBCTxRequest() {
 	res, err := rest.PostRequest(fmt.Sprintf("%s/txs", val.APIAddress), "application/json", []byte(req))
 	s.Require().NoError(err)
 
-	// Make sure the error message is correct.
-	s.Require().Contains(string(res), "this transaction cannot be broadcasted via legacy REST endpoints")
+	s.Require().NotContains(string(res), "this transaction cannot be broadcasted via legacy REST endpoints", string(res))
 }
 
 // Helper function to test querying txs. We will use it to query StdTx and service `Msg`s.

x/ibc/applications/transfer/module.go

@@ -46,7 +46,9 @@ func (AppModuleBasic) Name() string {
 }
 
 // RegisterLegacyAminoCodec implements AppModuleBasic interface
-func (AppModuleBasic) RegisterLegacyAminoCodec(*codec.LegacyAmino) {}
+func (AppModuleBasic) RegisterLegacyAminoCodec(cdc *codec.LegacyAmino) {
+	types.RegisterLegacyAminoCodec(cdc)
+}
 
 // RegisterInterfaces registers module concrete types into protobuf Any.
 func (AppModuleBasic) RegisterInterfaces(registry codectypes.InterfaceRegistry) {

x/ibc/applications/transfer/types/codec.go

@@ -7,6 +7,12 @@ import (
 	"github.com/cosmos/cosmos-sdk/types/msgservice"
 )
 
+// RegisterLegacyAminoCodec registers the necessary x/ibc transfer interfaces and concrete types
+// on the provided LegacyAmino codec. These types are used for Amino JSON serialization.
+func RegisterLegacyAminoCodec(cdc *codec.LegacyAmino) {
+	cdc.RegisterConcrete(&MsgTransfer{}, "cosmos-sdk/MsgTransfer", nil)
+}
+
 // RegisterInterfaces register the ibc transfer module interfaces to protobuf
 // Any.
 func RegisterInterfaces(registry codectypes.InterfaceRegistry) {
@@ -16,10 +22,20 @@ func RegisterInterfaces(registry codectypes.InterfaceRegistry) {
 }
 
 var (
+	amino = codec.NewLegacyAmino()
+
 	// ModuleCdc references the global x/ibc-transfer module codec. Note, the codec
 	// should ONLY be used in certain instances of tests and for JSON encoding.
 	//
-	// The actual codec used for serialization should be provided to x/ibc-transfer and
+	// The actual codec used for serialization should be provided to x/ibc transfer and
 	// defined at the application level.
 	ModuleCdc = codec.NewProtoCodec(codectypes.NewInterfaceRegistry())
+
+	// AminoCdc is a amino codec created to support amino json compatible msgs.
+	AminoCdc = codec.NewAminoCodec(amino)
 )
+
+func init() {
+	RegisterLegacyAminoCodec(amino)
+	amino.Seal()
+}

x/ibc/applications/transfer/types/msgs.go

@@ -70,10 +70,9 @@ func (msg MsgTransfer) ValidateBasic() error {
 	return ValidateIBCDenom(msg.Token.Denom)
 }
 
-// GetSignBytes implements sdk.Msg. The function will panic since it is used
-// for amino transaction verification which IBC does not support.
+// GetSignBytes implements sdk.Msg.
 func (msg MsgTransfer) GetSignBytes() []byte {
-	panic("IBC messages do not support amino")
+	return sdk.MustSortJSON(AminoCdc.MustMarshalJSON(&msg))
 }
 
 // GetSigners implements sdk.Msg

x/ibc/applications/transfer/types/msgs_test.go

@@ -1,6 +1,7 @@
 package types
 
 import (
+	"fmt"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -51,6 +52,15 @@ func TestMsgTransferType(t *testing.T) {
 	require.Equal(t, "transfer", msg.Type())
 }
 
+func TestMsgTransferGetSignBytes(t *testing.T) {
+	msg := NewMsgTransfer(validPort, validChannel, coin, addr1, addr2, timeoutHeight, 0)
+	expected := fmt.Sprintf(`{"type":"cosmos-sdk/MsgTransfer","value":{"receiver":"%s","sender":"%s","source_channel":"testchannel","source_port":"testportid","timeout_height":{"revision_height":"10"},"token":{"amount":"100","denom":"atom"}}}`, addr2, addr1)
+	require.NotPanics(t, func() {
+		res := msg.GetSignBytes()
+		require.Equal(t, expected, string(res))
+	})
+}
+
 // TestMsgTransferValidation tests ValidateBasic for MsgTransfer
 func TestMsgTransferValidation(t *testing.T) {
 	testCases := []struct {