Merge pull request #132 from hyperledger-labs/prove-host-consensus-state

Add `ProveHostConsensusState` to StateProver interface

Signed-off-by: Jun Kimura <[email protected]>

chains/tendermint/prover.go

@@ -54,6 +54,12 @@ func (pr *Prover) ProveState(ctx core.QueryContext, path string, value []byte) (
 	}
 }
 
+// ProveHostConsensusState returns the existence proof of the consensus state at `height`
+// ibc-go doesn't use this proof, so it returns nil
+func (pr *Prover) ProveHostConsensusState(ctx core.QueryContext, height ibcexported.Height, consensusState ibcexported.ConsensusState) ([]byte, error) {
+	return nil, nil
+}
+
 /* LightClient implementation */
 
 // CreateInitialLightClientState creates a pair of ClientState and ConsensusState submitted to the counterparty chain as MsgCreateClient

core/connection.go

@@ -94,8 +94,10 @@ func createConnectionStep(src, dst *ProvableChain) (*RelayMsgs, error) {
 		srcUpdateHeaders, dstUpdateHeaders []Header
 		srcCsRes, dstCsRes                 *clienttypes.QueryClientStateResponse
 		srcCS, dstCS                       ibcexported.ClientState
-		srcCons, dstCons                   *clienttypes.QueryConsensusStateResponse
+		srcConsRes, dstConsRes             *clienttypes.QueryConsensusStateResponse
+		srcCons, dstCons                   ibcexported.ConsensusState
 		srcConsH, dstConsH                 ibcexported.Height
+		srcHostConsProof, dstHostConsProof []byte
 	)
 	err = retry.Do(func() error {
 		srcUpdateHeaders, dstUpdateHeaders, err = sh.SetupBothHeadersForUpdate(src, dst)
@@ -136,12 +138,26 @@ func createConnectionStep(src, dst *ProvableChain) (*RelayMsgs, error) {
 
 		// Store the heights
 		srcConsH, dstConsH = srcCS.GetLatestHeight(), dstCS.GetLatestHeight()
-		srcCons, dstCons, err = QueryClientConsensusStatePair(
+		srcConsRes, dstConsRes, err = QueryClientConsensusStatePair(
 			sh.GetQueryContext(src.ChainID()), sh.GetQueryContext(dst.ChainID()),
 			src, dst, srcConsH, dstConsH, true)
 		if err != nil {
 			return nil, err
 		}
+		if err := src.Codec().UnpackAny(srcConsRes.ConsensusState, &srcCons); err != nil {
+			return nil, err
+		}
+		if err := dst.Codec().UnpackAny(dstConsRes.ConsensusState, &dstCons); err != nil {
+			return nil, err
+		}
+		srcHostConsProof, err = src.ProveHostConsensusState(sh.GetQueryContext(src.ChainID()), dstCS.GetLatestHeight(), dstCons)
+		if err != nil {
+			return nil, err
+		}
+		dstHostConsProof, err = dst.ProveHostConsensusState(sh.GetQueryContext(dst.ChainID()), srcCS.GetLatestHeight(), srcCons)
+		if err != nil {
+			return nil, err
+		}
 	}
 
 	switch {
@@ -160,15 +176,15 @@ func createConnectionStep(src, dst *ProvableChain) (*RelayMsgs, error) {
 		if len(dstUpdateHeaders) > 0 {
 			out.Src = append(out.Src, src.Path().UpdateClients(dstUpdateHeaders, addr)...)
 		}
-		out.Src = append(out.Src, src.Path().ConnTry(dst.Path(), dstCsRes, dstConn, dstCons, addr))
+		out.Src = append(out.Src, src.Path().ConnTry(dst.Path(), dstCsRes, dstConn, dstConsRes, srcHostConsProof, addr))
 	// Handshake has started on src (1 step done), relay `connOpenTry` and `updateClient` on dst
 	case srcConn.Connection.State == conntypes.INIT && dstConn.Connection.State == conntypes.UNINITIALIZED:
 		logConnectionStates(dst, src, dstConn, srcConn)
 		addr := mustGetAddress(dst)
 		if len(srcUpdateHeaders) > 0 {
 			out.Dst = append(out.Dst, dst.Path().UpdateClients(srcUpdateHeaders, addr)...)
 		}
-		out.Dst = append(out.Dst, dst.Path().ConnTry(src.Path(), srcCsRes, srcConn, srcCons, addr))
+		out.Dst = append(out.Dst, dst.Path().ConnTry(src.Path(), srcCsRes, srcConn, srcConsRes, dstHostConsProof, addr))
 
 	// Handshake has started on src end (2 steps done), relay `connOpenAck` and `updateClient` to dst end
 	case srcConn.Connection.State == conntypes.TRYOPEN && dstConn.Connection.State == conntypes.INIT:
@@ -177,7 +193,7 @@ func createConnectionStep(src, dst *ProvableChain) (*RelayMsgs, error) {
 		if len(srcUpdateHeaders) > 0 {
 			out.Dst = append(out.Dst, dst.Path().UpdateClients(srcUpdateHeaders, addr)...)
 		}
-		out.Dst = append(out.Dst, dst.Path().ConnAck(src.Path(), srcCsRes, srcConn, srcCons, addr))
+		out.Dst = append(out.Dst, dst.Path().ConnAck(src.Path(), srcCsRes, srcConn, srcConsRes, addr))
 
 	// Handshake has started on dst end (2 steps done), relay `connOpenAck` and `updateClient` to src end
 	case srcConn.Connection.State == conntypes.INIT && dstConn.Connection.State == conntypes.TRYOPEN:
@@ -186,7 +202,7 @@ func createConnectionStep(src, dst *ProvableChain) (*RelayMsgs, error) {
 		if len(dstUpdateHeaders) > 0 {
 			out.Src = append(out.Src, src.Path().UpdateClients(dstUpdateHeaders, addr)...)
 		}
-		out.Src = append(out.Src, src.Path().ConnAck(dst.Path(), dstCsRes, dstConn, dstCons, addr))
+		out.Src = append(out.Src, src.Path().ConnAck(dst.Path(), dstCsRes, dstConn, dstConsRes, addr))
 
 	// Handshake has confirmed on dst (3 steps done), relay `connOpenConfirm` and `updateClient` to src end
 	case srcConn.Connection.State == conntypes.TRYOPEN && dstConn.Connection.State == conntypes.OPEN:

core/pathEnd.go

@@ -92,6 +92,7 @@ func (pe *PathEnd) ConnTry(
 	dstClientState *clienttypes.QueryClientStateResponse,
 	dstConnState *conntypes.QueryConnectionResponse,
 	dstConsState *clienttypes.QueryConsensusStateResponse,
+	hostConsensusStateProof []byte,
 	signer sdk.AccAddress,
 ) sdk.Msg {
 	cs, err := clienttypes.UnpackClientState(dstClientState.ClientState)
@@ -113,6 +114,7 @@ func (pe *PathEnd) ConnTry(
 		cs.GetLatestHeight().(clienttypes.Height),
 		signer.String(),
 	)
+	msg.HostConsensusStateProof = hostConsensusStateProof
 	if err = msg.ValidateBasic(); err != nil {
 		panic(err)
 	}

core/provers.go

@@ -26,7 +26,12 @@ type Prover interface {
 
 // StateProver provides a generic way to generate existence proof of IBC states (e.g. ClientState, Connection, PacketCommitment, etc.)
 type StateProver interface {
+	// ProveState returns a proof of an IBC state specified by `path` and `value`
 	ProveState(ctx QueryContext, path string, value []byte) (proof []byte, proofHeight clienttypes.Height, err error)
+
+	// ProveHostConsensusState returns an existence proof of the consensus state at `height`
+	// This proof would be ignored in ibc-go, but it is required to `getSelfConsensusState` of ibc-solidity.
+	ProveHostConsensusState(ctx QueryContext, height exported.Height, consensusState exported.ConsensusState) (proof []byte, err error)
 }
 
 // LightClient provides functions for creating and updating on-chain light clients on the counterparty chain

provers/mock/prover.go

@@ -120,6 +120,11 @@ func (pr *Prover) ProveState(ctx core.QueryContext, path string, value []byte) (
 	return makeProof(value), ctx.Height().(clienttypes.Height), nil
 }
 
+// ProveHostConsensusState returns the proof of the consensus state at `height`
+func (pr *Prover) ProveHostConsensusState(ctx core.QueryContext, height exported.Height, consensusState exported.ConsensusState) ([]byte, error) {
+	return clienttypes.MarshalConsensusState(pr.chain.Codec(), consensusState)
+}
+
 func makeProof(bz []byte) []byte {
 	h := sha256.Sum256(bz)
 	return h[:]