abci: Vote Extension 2

abci/client/grpc_client.go

@@ -343,13 +343,13 @@ func (cli *grpcClient) VerifyVoteExtensionAsync(
 	}
 	return cli.finishAsyncCall(
 		ctx,
-    req,
+		req,
 		&types.Response{
-      Value: &types.Response_VerifyVoteExtension{
-        VerifyVoteExtension: res,
-      },
-    },
-  )
+			Value: &types.Response_VerifyVoteExtension{
+				VerifyVoteExtension: res,
+			},
+		},
+	)
 }
 
 func (cli *grpcClient) PrepareProposalAsync(
@@ -359,14 +359,14 @@ func (cli *grpcClient) PrepareProposalAsync(
 
 	req := types.ToRequestPrepareProposal(params)
 	res, err := cli.client.PrepareProposal(ctx, req.GetPrepareProposal(), grpc.WaitForReady(true))
-  if err != nil {
-    return nil, err
-  }
-
-  return cli.finishAsyncCall(
-    ctx,
-    req,
-    &types.Response{
+	if err != nil {
+		return nil, err
+	}
+
+	return cli.finishAsyncCall(
+		ctx,
+		req,
+		&types.Response{
 			Value: &types.Response_PrepareProposal{
 				PrepareProposal: res,
 			},
@@ -584,7 +584,7 @@ func (cli *grpcClient) VerifyVoteExtensionSync(
 	if err != nil {
 		return nil, err
 	}
-  return cli.finishSyncCall(reqres).GetVerifyVoteExtension(), cli.Error()
+	return cli.finishSyncCall(reqres).GetVerifyVoteExtension(), cli.Error()
 }
 
 func (cli *grpcClient) PrepareProposalSync(

abci/client/local_client.go

@@ -236,14 +236,14 @@ func (app *localClient) PrepareProposalAsync(
 	ctx context.Context,
 	req types.RequestPrepareProposal,
 ) (*ReqRes, error) {
-  app.mtx.Lock()
-  defer app.mtx.Unlock()
+	app.mtx.Lock()
+	defer app.mtx.Unlock()
 
-  res := app.Application.PrepareProposal(req)
+	res := app.Application.PrepareProposal(req)
 	return app.callback(
 		types.ToRequestPrepareProposal(req),
 		types.ToResponsePrepareProposal(res),
-  ), nil
+	), nil
 }
 
 //-------------------------------------------------------
@@ -407,15 +407,15 @@ func (app *localClient) VerifyVoteExtensionSync(
 	defer app.mtx.Unlock()
 
 	res := app.Application.VerifyVoteExtension(req)
-  return &res, nil
+	return &res, nil
 }
 
 func (app *localClient) PrepareProposalSync(
 	ctx context.Context,
 	req types.RequestPrepareProposal,
 ) (*types.ResponsePrepareProposal, error) {
-  app.mtx.Lock()
-  defer app.mtx.Unlock()
+	app.mtx.Lock()
+	defer app.mtx.Unlock()
 
 	res := app.Application.PrepareProposal(req)
 	return &res, nil

abci/example/kvstore/persistent_kvstore.go

@@ -14,6 +14,7 @@ import (
 	cryptoenc "github.com/tendermint/tendermint/crypto/encoding"
 	"github.com/tendermint/tendermint/libs/log"
 	pc "github.com/tendermint/tendermint/proto/tendermint/crypto"
+	ptypes "github.com/tendermint/tendermint/proto/tendermint/types"
 )
 
 const (
@@ -76,6 +77,10 @@ func (app *PersistentKVStoreApplication) DeliverTx(req types.RequestDeliverTx) t
 		return app.execValidatorTx(req.Tx)
 	}
 
+	if isPrepareTx(req.Tx) {
+		return app.execPrepareTx(req.Tx)
+	}
+
 	// otherwise, update the key-value store
 	return app.app.DeliverTx(req)
 }
@@ -172,21 +177,20 @@ func (app *PersistentKVStoreApplication) ApplySnapshotChunk(
 
 func (app *PersistentKVStoreApplication) ExtendVote(
 	req types.RequestExtendVote) types.ResponseExtendVote {
-	return types.ResponseExtendVote{}
+	return types.ResponseExtendVote{
+		VoteExtension: ConstructVoteExtension(req.Vote.ValidatorAddress),
+	}
 }
 
 func (app *PersistentKVStoreApplication) VerifyVoteExtension(
 	req types.RequestVerifyVoteExtension) types.ResponseVerifyVoteExtension {
-	return types.ResponseVerifyVoteExtension{}
+	return types.RespondVerifyVoteExtension(
+		app.verifyExtension(req.Vote.ValidatorAddress, req.Vote.VoteExtension))
 }
 
 func (app *PersistentKVStoreApplication) PrepareProposal(
 	req types.RequestPrepareProposal) types.ResponsePrepareProposal {
-	if len(req.BlockData) >= 1 {
-		req.BlockData[1] = []byte("modified tx")
-	}
-
-	return types.ResponsePrepareProposal{BlockData: req.BlockData}
+	return types.ResponsePrepareProposal{BlockData: app.substPrepareTx(req.BlockData)}
 }
 
 //---------------------------------------------
@@ -303,3 +307,51 @@ func (app *PersistentKVStoreApplication) updateValidator(v types.ValidatorUpdate
 
 	return types.ResponseDeliverTx{Code: code.CodeTypeOK}
 }
+
+// -----------------------------
+
+const PreparePrefix = "prepare"
+
+func isPrepareTx(tx []byte) bool {
+	return strings.HasPrefix(string(tx), PreparePrefix)
+}
+
+// execPrepareTx is noop. tx data is considered as placeholder
+// and is substitute at the PrepareProposal.
+func (app *PersistentKVStoreApplication) execPrepareTx(tx []byte) types.ResponseDeliverTx {
+	// noop
+	return types.ResponseDeliverTx{}
+}
+
+// substPrepareTx subst all the preparetx in the blockdata
+// to null string(could be any arbitrary string).
+func (app *PersistentKVStoreApplication) substPrepareTx(blockData [][]byte) [][]byte {
+	for i, tx := range blockData {
+		if isPrepareTx(tx) {
+			blockData[i] = make([]byte, len(tx))
+		}
+	}
+
+	return blockData
+}
+
+func ConstructVoteExtension(valAddr []byte) *ptypes.VoteExtension {
+	return &ptypes.VoteExtension{
+		AppDataToSign:             valAddr,
+		AppDataSelfAuthenticating: valAddr,
+	}
+}
+
+func (app *PersistentKVStoreApplication) verifyExtension(valAddr []byte, ext *ptypes.VoteExtension) bool {
+	if ext == nil {
+		return false
+	}
+	canonical := ConstructVoteExtension(valAddr)
+	if !bytes.Equal(canonical.AppDataToSign, ext.AppDataToSign) {
+		return false
+	}
+	if !bytes.Equal(canonical.AppDataSelfAuthenticating, ext.AppDataSelfAuthenticating) {
+		return false
+	}
+	return true
+}

abci/types/application.go

@@ -19,12 +19,18 @@ type Application interface {
 	// Consensus Connection
 	InitChain(RequestInitChain) ResponseInitChain // Initialize blockchain w validators/other info from TendermintCore
 	PrepareProposal(RequestPrepareProposal) ResponsePrepareProposal
-	BeginBlock(RequestBeginBlock) ResponseBeginBlock // Signals the beginning of a block
-	DeliverTx(RequestDeliverTx) ResponseDeliverTx    // Deliver a tx for full processing
-	EndBlock(RequestEndBlock) ResponseEndBlock       // Signals the end of a block, returns changes to the validator set
-	Commit() ResponseCommit                          // Commit the state and return the application Merkle root hash
-	ExtendVote(RequestExtendVote) ResponseExtendVote                            // Create application specific vote extension
-	VerifyVoteExtension(RequestVerifyVoteExtension) ResponseVerifyVoteExtension // Verify application's vote extension data
+	// Signals the beginning of a block
+	BeginBlock(RequestBeginBlock) ResponseBeginBlock
+	// Deliver a tx for full processing
+	DeliverTx(RequestDeliverTx) ResponseDeliverTx
+	// Signals the end of a block, returns changes to the validator set
+	EndBlock(RequestEndBlock) ResponseEndBlock
+	// Commit the state and return the application Merkle root hash
+	Commit() ResponseCommit
+	// Create application specific vote extension
+	ExtendVote(RequestExtendVote) ResponseExtendVote
+	// Verify application's vote extension data
+	VerifyVoteExtension(RequestVerifyVoteExtension) ResponseVerifyVoteExtension
 
 	// State Sync Connection
 	ListSnapshots(RequestListSnapshots) ResponseListSnapshots                // List available snapshots
@@ -197,7 +203,7 @@ func (app *GRPCApplication) ExtendVote(
 func (app *GRPCApplication) VerifyVoteExtension(
 	ctx context.Context, req *RequestVerifyVoteExtension) (*ResponseVerifyVoteExtension, error) {
 	res := app.app.VerifyVoteExtension(*req)
-  return &res, nil
+	return &res, nil
 }
 
 func (app *GRPCApplication) PrepareProposal(

abci/types/messages.go

@@ -119,7 +119,7 @@ func ToRequestExtendVote(req RequestExtendVote) *Request {
 func ToRequestVerifyVoteExtension(req RequestVerifyVoteExtension) *Request {
 	return &Request{
 		Value: &Request_VerifyVoteExtension{&req},
-  }
+	}
 }
 
 func ToRequestPrepareProposal(req RequestPrepareProposal) *Request {
@@ -228,7 +228,7 @@ func ToResponseExtendVote(res ResponseExtendVote) *Response {
 func ToResponseVerifyVoteExtension(res ResponseVerifyVoteExtension) *Response {
 	return &Response{
 		Value: &Response_VerifyVoteExtension{&res},
-  }
+	}
 }
 
 func ToResponsePrepareProposal(res ResponsePrepareProposal) *Response {

abci/types/result.go

@@ -5,6 +5,8 @@ import (
 	"encoding/json"
 
 	"github.com/gogo/protobuf/jsonpb"
+
+	types "github.com/tendermint/tendermint/proto/tendermint/types"
 )
 
 const (
@@ -41,6 +43,16 @@ func (r ResponseQuery) IsErr() bool {
 	return r.Code != CodeTypeOK
 }
 
+// IsOK returns true if Code is OK
+func (r ResponseVerifyVoteExtension) IsOK() bool {
+	return r.Result <= ResponseVerifyVoteExtension_ACCEPT
+}
+
+// IsErr returns true if Code is something other than OK.
+func (r ResponseVerifyVoteExtension) IsErr() bool {
+	return r.Result > ResponseVerifyVoteExtension_ACCEPT
+}
+
 //---------------------------------------------------------------------------
 // override JSON marshaling so we emit defaults (ie. disable omitempty)
 
@@ -118,3 +130,25 @@ var _ jsonRoundTripper = (*ResponseDeliverTx)(nil)
 var _ jsonRoundTripper = (*ResponseCheckTx)(nil)
 
 var _ jsonRoundTripper = (*EventAttribute)(nil)
+
+// -----------------------------------------------
+// construct Result data
+
+func RespondExtendVote(appDataToSign, appDataSelfAuthenticating []byte) ResponseExtendVote {
+	return ResponseExtendVote{
+		VoteExtension: &types.VoteExtension{
+			AppDataToSign:             appDataToSign,
+			AppDataSelfAuthenticating: appDataSelfAuthenticating,
+		},
+	}
+}
+
+func RespondVerifyVoteExtension(ok bool) ResponseVerifyVoteExtension {
+	result := ResponseVerifyVoteExtension_REJECT
+	if ok {
+		result = ResponseVerifyVoteExtension_ACCEPT
+	}
+	return ResponseVerifyVoteExtension{
+		Result: result,
+	}
+}