Parse ICS20 denomination using channel identifier format

CHANGELOG.md

@@ -59,6 +59,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Improvements
 
+* (app/20-transfer) [\#1730](https://github.com/cosmos/ibc-go/pull/1730) parse the ics20 denomination provided via a packet using the channel identifier format specified by ibc-go.
 * (cleanup) [\#1335](https://github.com/cosmos/ibc-go/pull/1335/) `gofumpt -w -l .` to standardize the code layout more strictly than `go fmt ./...`
 * (middleware) [\#1022](https://github.com/cosmos/ibc-go/pull/1022) Add `GetAppVersion` to the ICS4Wrapper interface. This function should be used by IBC applications to obtain their own version since the version set in the channel structure may be wrapped many times by middleware. 
 * (modules/core/04-channel) [\#1232](https://github.com/cosmos/ibc-go/pull/1232) Updating params on `NewPacketId` and moving to bottom of file.

modules/apps/transfer/keeper/migrations.go

@@ -1,6 +1,8 @@
 package keeper
 
 import (
+	"fmt"
+
 	sdk "github.com/cosmos/cosmos-sdk/types"
 
 	"github.com/cosmos/ibc-go/v4/modules/apps/transfer/types"
@@ -34,6 +36,14 @@ func (m Migrator) MigrateTraces(ctx sdk.Context) error {
 				iterErr = err
 				return true
 			}
+
+			if dt.IBCDenom() != newTrace.IBCDenom() {
+				// The new form of parsing will result in a token denomination change.
+				// A bank migration is required. A panic should occur to prevent the
+				// chain from using corrupted state.
+				panic(fmt.Sprintf("migration will result in corrupted state. Previous IBC token (%s) requires a bank migration. Expected denom trace (%s)", dt, newTrace))
+			}
+
 			if !equalTraces(newTrace, dt) {
 				newTraces = append(newTraces, newTrace)
 			}

modules/apps/transfer/keeper/migrations_test.go

@@ -76,8 +76,7 @@ func (suite *KeeperTestSuite) TestMigratorMigrateTraces() {
 			},
 		},
 		{
-			// the expected value will change with the implementation of the fix for #1698
-			"no change: non-standard port",
+			"success: non-standard port",
 			func() {
 				suite.chainA.GetSimApp().TransferKeeper.SetDenomTrace(
 					suite.chainA.GetContext(),
@@ -87,7 +86,7 @@ func (suite *KeeperTestSuite) TestMigratorMigrateTraces() {
 			},
 			transfertypes.Traces{
 				{
-					BaseDenom: "customport/channel-7/uatom", Path: "transfer/channel-0/transfer/channel-1",
+					BaseDenom: "uatom", Path: "transfer/channel-0/transfer/channel-1/customport/channel-7",
 				},
 			},
 		},
@@ -108,3 +107,16 @@ func (suite *KeeperTestSuite) TestMigratorMigrateTraces() {
 		})
 	}
 }
+
+func (suite *KeeperTestSuite) TestMigratorMigrateTracesCorruptionDetection() {
+	// IBCDenom() previously would return "customport/channel-0/uatom", but now should return ibc/{hash}
+	corruptedDenomTrace := transfertypes.DenomTrace{
+		BaseDenom: "customport/channel-0/uatom", Path: "",
+	}
+	suite.chainA.GetSimApp().TransferKeeper.SetDenomTrace(suite.chainA.GetContext(), corruptedDenomTrace)
+
+	migrator := transferkeeper.NewMigrator(suite.chainA.GetSimApp().TransferKeeper)
+	suite.Panics(func() {
+		migrator.MigrateTraces(suite.chainA.GetContext())
+	})
+}

modules/apps/transfer/types/trace.go

@@ -12,6 +12,7 @@ import (
 	tmbytes "github.com/tendermint/tendermint/libs/bytes"
 	tmtypes "github.com/tendermint/tendermint/types"
 
+	channeltypes "github.com/cosmos/ibc-go/v4/modules/core/04-channel/types"
 	host "github.com/cosmos/ibc-go/v4/modules/core/24-host"
 )
 
@@ -80,11 +81,23 @@ func (dt DenomTrace) GetFullDenomPath() string {
 // extractPathAndBaseFromFullDenom returns the trace path and the base denom from
 // the elements that constitute the complete denom.
 func extractPathAndBaseFromFullDenom(fullDenomItems []string) (string, string) {
-	var path []string
-	var baseDenom []string
+	var (
+		path      []string
+		baseDenom []string
+	)
+
 	length := len(fullDenomItems)
 	for i := 0; i < length; i = i + 2 {
-		if i < length-1 && length > 2 && fullDenomItems[i] == PortID {
+		// The IBC specification does not guarentee the expected format of the
+		// destination port or destination channel identifier. A short term solution
+		// to determine base denomination is to expect the channel idenitifer to be the
+		// one ibc-go specifies. A longer term solution is to separate the path and base
+		// denomination in the ICS20 packet. If an intermediate hop prefixes the full denom
+		// with a channel identifier format different from our own, the base denomination
+		// will be incorrectly parsed, but the token will continue to be treated correctly
+		// as an IBC denomination. The hash used to store the token internally on our chain
+		// will be the same value as the base denomination being correctly parsed.
+		if i < length-1 && length > 2 && channeltypes.IsValidChannelID(fullDenomItems[i+1]) {
 			path = append(path, fullDenomItems[i], fullDenomItems[i+1])
 		} else {
 			baseDenom = fullDenomItems[i:]

modules/apps/transfer/types/trace_test.go

@@ -17,20 +17,23 @@ func TestParseDenomTrace(t *testing.T) {
 		{"base denom ending with '/'", "uatom/", DenomTrace{BaseDenom: "uatom/"}},
 		{"base denom with single '/'s", "gamm/pool/1", DenomTrace{BaseDenom: "gamm/pool/1"}},
 		{"base denom with double '/'s", "gamm//pool//1", DenomTrace{BaseDenom: "gamm//pool//1"}},
-		{"trace info", "transfer/channelToA/uatom", DenomTrace{BaseDenom: "uatom", Path: "transfer/channelToA"}},
-		{"trace info with base denom ending in '/'", "transfer/channelToA/uatom/", DenomTrace{BaseDenom: "uatom/", Path: "transfer/channelToA"}},
-		{"trace info with single '/' in base denom", "transfer/channelToA/erc20/0x85bcBCd7e79Ec36f4fBBDc54F90C643d921151AA", DenomTrace{BaseDenom: "erc20/0x85bcBCd7e79Ec36f4fBBDc54F90C643d921151AA", Path: "transfer/channelToA"}},
-		{"trace info with multiple '/'s in base denom", "transfer/channelToA/gamm/pool/1", DenomTrace{BaseDenom: "gamm/pool/1", Path: "transfer/channelToA"}},
-		{"trace info with multiple double '/'s in base denom", "transfer/channelToA/gamm//pool//1", DenomTrace{BaseDenom: "gamm//pool//1", Path: "transfer/channelToA"}},
-		{"trace info with multiple port/channel pairs", "transfer/channelToA/transfer/channelToB/uatom", DenomTrace{BaseDenom: "uatom", Path: "transfer/channelToA/transfer/channelToB"}},
+		{"trace info", "transfer/channel-1/uatom", DenomTrace{BaseDenom: "uatom", Path: "transfer/channel-1"}},
+		{"trace info with custom port", "customtransfer/channel-1/uatom", DenomTrace{BaseDenom: "uatom", Path: "customtransfer/channel-1"}},
+		{"trace info with base denom ending in '/'", "transfer/channel-1/uatom/", DenomTrace{BaseDenom: "uatom/", Path: "transfer/channel-1"}},
+		{"trace info with single '/' in base denom", "transfer/channel-1/erc20/0x85bcBCd7e79Ec36f4fBBDc54F90C643d921151AA", DenomTrace{BaseDenom: "erc20/0x85bcBCd7e79Ec36f4fBBDc54F90C643d921151AA", Path: "transfer/channel-1"}},
+		{"trace info with multiple '/'s in base denom", "transfer/channel-1/gamm/pool/1", DenomTrace{BaseDenom: "gamm/pool/1", Path: "transfer/channel-1"}},
+		{"trace info with multiple double '/'s in base denom", "transfer/channel-1/gamm//pool//1", DenomTrace{BaseDenom: "gamm//pool//1", Path: "transfer/channel-1"}},
+		{"trace info with multiple port/channel pairs", "transfer/channel-1/transfer/channel-2/uatom", DenomTrace{BaseDenom: "uatom", Path: "transfer/channel-1/transfer/channel-2"}},
+		{"trace info with multiple custom ports", "customtransfer/channel-1/alternativetransfer/channel-2/uatom", DenomTrace{BaseDenom: "uatom", Path: "customtransfer/channel-1/alternativetransfer/channel-2"}},
 		{"incomplete path", "transfer/uatom", DenomTrace{BaseDenom: "transfer/uatom"}},
-		{"invalid path (1)", "transfer//uatom", DenomTrace{BaseDenom: "uatom", Path: "transfer/"}},
-		{"invalid path (2)", "channelToA/transfer/uatom", DenomTrace{BaseDenom: "channelToA/transfer/uatom"}},
+		{"invalid path (1)", "transfer//uatom", DenomTrace{BaseDenom: "transfer//uatom", Path: ""}},
+		{"invalid path (2)", "channel-1/transfer/uatom", DenomTrace{BaseDenom: "channel-1/transfer/uatom"}},
 		{"invalid path (3)", "uatom/transfer", DenomTrace{BaseDenom: "uatom/transfer"}},
-		{"invalid path (4)", "transfer/channelToA", DenomTrace{BaseDenom: "transfer/channelToA"}},
-		{"invalid path (5)", "transfer/channelToA/", DenomTrace{Path: "transfer/channelToA"}},
-		{"invalid path (6)", "transfer/channelToA/transfer", DenomTrace{BaseDenom: "transfer", Path: "transfer/channelToA"}},
-		{"invalid path (7)", "transfer/channelToA/transfer/channelToB", DenomTrace{Path: "transfer/channelToA/transfer/channelToB"}},
+		{"invalid path (4)", "transfer/channel-1", DenomTrace{BaseDenom: "transfer/channel-1"}},
+		{"invalid path (5)", "transfer/channel-1/", DenomTrace{Path: "transfer/channel-1"}},
+		{"invalid path (6)", "transfer/channel-1/transfer", DenomTrace{BaseDenom: "transfer", Path: "transfer/channel-1"}},
+		{"invalid path (7)", "transfer/channel-1/transfer/channel-2", DenomTrace{Path: "transfer/channel-1/transfer/channel-2"}},
+		{"invalid path (8)", "transfer/channelToA/uatom", DenomTrace{BaseDenom: "transfer/channelToA/uatom", Path: ""}},
 	}
 
 	for _, tc := range testCases {
@@ -46,7 +49,7 @@ func TestDenomTrace_IBCDenom(t *testing.T) {
 		expDenom string
 	}{
 		{"base denom", DenomTrace{BaseDenom: "uatom"}, "uatom"},
-		{"trace info", DenomTrace{BaseDenom: "uatom", Path: "transfer/channelToA"}, "ibc/7F1D3FCF4AE79E1554D670D1AD949A9BA4E4A3C76C63093E17E446A46061A7A2"},
+		{"trace info", DenomTrace{BaseDenom: "uatom", Path: "transfer/channel-1"}, "ibc/C4CFF46FD6DE35CA4CF4CE031E643C8FDC9BA4B99AE598E9B0ED98FE3A2319F9"},
 	}
 
 	for _, tc := range testCases {
@@ -65,12 +68,12 @@ func TestDenomTrace_Validate(t *testing.T) {
 		{"base denom only with single '/'", DenomTrace{BaseDenom: "erc20/0x85bcBCd7e79Ec36f4fBBDc54F90C643d921151AA"}, false},
 		{"base denom only with multiple '/'s", DenomTrace{BaseDenom: "gamm/pool/1"}, false},
 		{"empty DenomTrace", DenomTrace{}, true},
-		{"valid single trace info", DenomTrace{BaseDenom: "uatom", Path: "transfer/channelToA"}, false},
-		{"valid multiple trace info", DenomTrace{BaseDenom: "uatom", Path: "transfer/channelToA/transfer/channelToB"}, false},
+		{"valid single trace info", DenomTrace{BaseDenom: "uatom", Path: "transfer/channel-1"}, false},
+		{"valid multiple trace info", DenomTrace{BaseDenom: "uatom", Path: "transfer/channel-1/transfer/channel-2"}, false},
 		{"single trace identifier", DenomTrace{BaseDenom: "uatom", Path: "transfer"}, true},
-		{"invalid port ID", DenomTrace{BaseDenom: "uatom", Path: "(transfer)/channelToA"}, true},
-		{"invalid channel ID", DenomTrace{BaseDenom: "uatom", Path: "transfer/(channelToA)"}, true},
-		{"empty base denom with trace", DenomTrace{BaseDenom: "", Path: "transfer/channelToA"}, true},
+		{"invalid port ID", DenomTrace{BaseDenom: "uatom", Path: "(transfer)/channel-1"}, true},
+		{"invalid channel ID", DenomTrace{BaseDenom: "uatom", Path: "transfer/(channel-1)"}, true},
+		{"empty base denom with trace", DenomTrace{BaseDenom: "", Path: "transfer/channel-1"}, true},
 	}
 
 	for _, tc := range testCases {
@@ -90,16 +93,16 @@ func TestTraces_Validate(t *testing.T) {
 		expError bool
 	}{
 		{"empty Traces", Traces{}, false},
-		{"valid multiple trace info", Traces{{BaseDenom: "uatom", Path: "transfer/channelToA/transfer/channelToB"}}, false},
+		{"valid multiple trace info", Traces{{BaseDenom: "uatom", Path: "transfer/channel-1/transfer/channel-2"}}, false},
 		{
 			"valid multiple trace info",
 			Traces{
-				{BaseDenom: "uatom", Path: "transfer/channelToA/transfer/channelToB"},
-				{BaseDenom: "uatom", Path: "transfer/channelToA/transfer/channelToB"},
+				{BaseDenom: "uatom", Path: "transfer/channel-1/transfer/channel-2"},
+				{BaseDenom: "uatom", Path: "transfer/channel-1/transfer/channel-2"},
 			},
 			true,
 		},
-		{"empty base denom with trace", Traces{{BaseDenom: "", Path: "transfer/channelToA"}}, true},
+		{"empty base denom with trace", Traces{{BaseDenom: "", Path: "transfer/channel-1"}}, true},
 	}
 
 	for _, tc := range testCases {
@@ -118,26 +121,25 @@ func TestValidatePrefixedDenom(t *testing.T) {
 		denom    string
 		expError bool
 	}{
-		{"prefixed denom", "transfer/channelToA/uatom", false},
-		{"prefixed denom with '/'", "transfer/channelToA/gamm/pool/1", false},
+		{"prefixed denom", "transfer/channel-1/uatom", false},
+		{"prefixed denom with '/'", "transfer/channel-1/gamm/pool/1", false},
 		{"empty prefix", "/uatom", false},
 		{"empty identifiers", "//uatom", false},
 		{"base denom", "uatom", false},
 		{"base denom with single '/'", "erc20/0x85bcBCd7e79Ec36f4fBBDc54F90C643d921151AA", false},
 		{"base denom with multiple '/'s", "gamm/pool/1", false},
-		{"invalid port ID", "(transfer)/channelToA/uatom", false},
+		{"invalid port ID", "(transfer)/channel-1/uatom", true},
 		{"empty denom", "", true},
 		{"single trace identifier", "transfer/", true},
-		{"invalid channel ID", "transfer/(channelToA)/uatom", true},
 	}
 
 	for _, tc := range testCases {
 		err := ValidatePrefixedDenom(tc.denom)
 		if tc.expError {
 			require.Error(t, err, tc.name)
-			continue
+		} else {
+			require.NoError(t, err, tc.name)
 		}
-		require.NoError(t, err, tc.name)
 	}
 }