Add an IBC prefix to transfer escrow addresses

x/ibc/applications/transfer/module.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"math"
 	"math/rand"
 
 	"github.com/grpc-ecosystem/grpc-gateway/runtime"
@@ -193,6 +194,14 @@ func (am AppModule) OnChanOpenInit(
 	counterparty channeltypes.Counterparty,
 	version string,
 ) error {
+	// NOTE: for escrow address security only 2^32 channels are allowed to be created
+	channelSequence, err := channeltypes.ParseChannelSequence(channelID)
+	if err != nil {
+		return err
+	}
+	if channelSequence > math.MaxUint32 {
+		return sdkerrors.Wrapf(types.ErrMaxTransferChannels, "channel sequence %d is greater than max allowed transfer channels %d", channelSequence, math.MaxUint32)
+	}
 	if order != channeltypes.UNORDERED {
 		return sdkerrors.Wrapf(channeltypes.ErrInvalidChannelOrdering, "expected %s channel, got %s ", channeltypes.UNORDERED, order)
 	}
@@ -227,6 +236,14 @@ func (am AppModule) OnChanOpenTry(
 	version,
 	counterpartyVersion string,
 ) error {
+	// NOTE: for escrow address security only 2^32 channels are allowed to be created
+	channelSequence, err := channeltypes.ParseChannelSequence(channelID)
+	if err != nil {
+		return err
+	}
+	if channelSequence > math.MaxUint32 {
+		return sdkerrors.Wrapf(types.ErrMaxTransferChannels, "channel sequence %d is greater than max allowed transfer channels %d", channelSequence, math.MaxUint32)
+	}
 	if order != channeltypes.UNORDERED {
 		return sdkerrors.Wrapf(channeltypes.ErrInvalidChannelOrdering, "expected %s channel, got %s ", channeltypes.UNORDERED, order)
 	}

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

@@ -13,4 +13,5 @@ var (
 	ErrTraceNotFound           = sdkerrors.Register(ModuleName, 6, "denomination trace not found")
 	ErrSendDisabled            = sdkerrors.Register(ModuleName, 7, "fungible token transfers from this chain are disabled")
 	ErrReceiveDisabled         = sdkerrors.Register(ModuleName, 8, "fungible token transfers to this chain are disabled")
+	ErrMaxTransferChannels     = sdkerrors.Register(ModuleName, 9, "max transfer channels")
 )

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

@@ -1,10 +1,9 @@
 package types
 
 import (
+	"crypto/sha256"
 	"fmt"
 
-	"github.com/tendermint/tendermint/crypto"
-
 	sdk "github.com/cosmos/cosmos-sdk/types"
 )
 
@@ -30,6 +29,10 @@ const (
 
 	// DenomPrefix is the prefix used for internal SDK coin representation.
 	DenomPrefix = "ibc"
+
+	// EscrowPrefix is the prefix used for IBC escrow addresses to avoid address collisions
+	// with Public Key addresses.
+	EscrowPrefix = "ibc-v1"
 )
 
 var (
@@ -39,11 +42,18 @@ var (
 	DenomTraceKey = []byte{0x02}
 )
 
-// GetEscrowAddress returns the escrow address for the specified channel
-//
-// CONTRACT: this assumes that there's only one bank bridge module that owns the
-// port associated with the channel ID so that the address created is actually
-// unique.
+// GetEscrowAddress returns the escrow address for the specified channel.
+// The escrow address follows the format as outlined in ADR 028:
+// https://github.com/cosmos/cosmos-sdk/blob/master/docs/architecture/adr-028-public-key-addresses.md
 func GetEscrowAddress(portID, channelID string) sdk.AccAddress {
-	return sdk.AccAddress(crypto.AddressHash([]byte(fmt.Sprintf("%s/%s", portID, channelID))))
+	// a slash is used to create domain separation between port and channel identifiers to
+	// prevent address collisions between escrow addresses created for different channels
+	contents := fmt.Sprintf("%s/%s", portID, channelID)
+
+	// ADR 028 AddressHash construction
+	preImage := []byte(EscrowPrefix)
+	preImage = append(preImage, 0)
+	preImage = append(preImage, contents...)
+	hash := sha256.Sum256(preImage)
+	return hash[:20]
 }