Merge PR cosmos#2192: Split LCD implementation PR, part one

client/context/context.go

@@ -1,14 +1,18 @@
 package context
 
 import (
-	"io"
-
+	"bytes"
+	"fmt"
 	"github.com/cosmos/cosmos-sdk/client"
 	"github.com/cosmos/cosmos-sdk/wire"
 	"github.com/cosmos/cosmos-sdk/x/auth"
+	"io"
 
 	"github.com/spf13/viper"
 
+	"github.com/tendermint/tendermint/libs/cli"
+	tmlite "github.com/tendermint/tendermint/lite"
+	tmliteProxy "github.com/tendermint/tendermint/lite/proxy"
 	rpcclient "github.com/tendermint/tendermint/rpc/client"
 )
 
@@ -32,6 +36,7 @@ type CLIContext struct {
 	Async           bool
 	JSON            bool
 	PrintResponse   bool
+	Certifier       tmlite.Certifier
 }
 
 // NewCLIContext returns a new initialized CLIContext with parameters from the
@@ -57,7 +62,38 @@ func NewCLIContext() CLIContext {
 		Async:           viper.GetBool(client.FlagAsync),
 		JSON:            viper.GetBool(client.FlagJson),
 		PrintResponse:   viper.GetBool(client.FlagPrintResponse),
+		Certifier:       createCertifier(),
+	}
+}
+
+func createCertifier() tmlite.Certifier {
+	trustNode := viper.GetBool(client.FlagTrustNode)
+	if trustNode {
+		return nil
+	}
+	chainID := viper.GetString(client.FlagChainID)
+	home := viper.GetString(cli.HomeFlag)
+	nodeURI := viper.GetString(client.FlagNode)
+
+	var errMsg bytes.Buffer
+	if chainID == "" {
+		errMsg.WriteString("chain-id ")
+	}
+	if home == "" {
+		errMsg.WriteString("home ")
+	}
+	if nodeURI == "" {
+		errMsg.WriteString("node ")
+	}
+	// errMsg is not empty
+	if errMsg.Len() != 0 {
+		panic(fmt.Errorf("can't create certifier for distrust mode, empty values from these options: %s", errMsg.String()))
 	}
+	certifier, err := tmliteProxy.GetCertifier(chainID, home, nodeURI)
+	if err != nil {
+		panic(err)
+	}
+	return certifier
 }
 
 // WithCodec returns a copy of the context with an updated codec.
@@ -117,3 +153,9 @@ func (ctx CLIContext) WithUseLedger(useLedger bool) CLIContext {
 	ctx.UseLedger = useLedger
 	return ctx
 }
+
+// WithCertifier - return a copy of the context with an updated Certifier
+func (ctx CLIContext) WithCertifier(certifier tmlite.Certifier) CLIContext {
+	ctx.Certifier = certifier
+	return ctx
+}

client/context/query.go

@@ -10,9 +10,14 @@ import (
 
 	"github.com/pkg/errors"
 
+	"github.com/cosmos/cosmos-sdk/store"
+	"github.com/cosmos/cosmos-sdk/wire"
+	abci "github.com/tendermint/tendermint/abci/types"
 	cmn "github.com/tendermint/tendermint/libs/common"
+	tmliteProxy "github.com/tendermint/tendermint/lite/proxy"
 	rpcclient "github.com/tendermint/tendermint/rpc/client"
 	ctypes "github.com/tendermint/tendermint/rpc/core/types"
+	"strings"
 )
 
 // GetNode returns an RPC client. If the context's client is not defined, an
@@ -304,12 +309,77 @@ func (ctx CLIContext) query(path string, key cmn.HexBytes) (res []byte, err erro
 		return res, errors.Errorf("query failed: (%d) %s", resp.Code, resp.Log)
 	}
 
+	// Data from trusted node or subspace query doesn't need verification
+	if ctx.TrustNode || !isQueryStoreWithProof(path) {
+		return resp.Value, nil
+	}
+
+	err = ctx.verifyProof(path, resp)
+	if err != nil {
+		return nil, err
+	}
+
 	return resp.Value, nil
 }
 
+// verifyProof perform response proof verification
+func (ctx CLIContext) verifyProof(path string, resp abci.ResponseQuery) error {
+
+	if ctx.Certifier == nil {
+		return fmt.Errorf("missing valid certifier to verify data from untrusted node")
+	}
+
+	node, err := ctx.GetNode()
+	if err != nil {
+		return err
+	}
+
+	// AppHash for height H is in header H+1
+	commit, err := tmliteProxy.GetCertifiedCommit(resp.Height+1, node, ctx.Certifier)
+	if err != nil {
+		return err
+	}
+
+	var multiStoreProof store.MultiStoreProof
+	cdc := wire.NewCodec()
+	err = cdc.UnmarshalBinary(resp.Proof, &multiStoreProof)
+	if err != nil {
+		return errors.Wrap(err, "failed to unmarshalBinary rangeProof")
+	}
+
+	// Verify the substore commit hash against trusted appHash
+	substoreCommitHash, err := store.VerifyMultiStoreCommitInfo(multiStoreProof.StoreName,
+		multiStoreProof.StoreInfos, commit.Header.AppHash)
+	if err != nil {
+		return errors.Wrap(err, "failed in verifying the proof against appHash")
+	}
+	err = store.VerifyRangeProof(resp.Key, resp.Value, substoreCommitHash, &multiStoreProof.RangeProof)
+	if err != nil {
+		return errors.Wrap(err, "failed in the range proof verification")
+	}
+	return nil
+}
+
 // queryStore performs a query from a Tendermint node with the provided a store
 // name and path.
 func (ctx CLIContext) queryStore(key cmn.HexBytes, storeName, endPath string) ([]byte, error) {
 	path := fmt.Sprintf("/store/%s/%s", storeName, endPath)
 	return ctx.query(path, key)
 }
+
+// isQueryStoreWithProof expects a format like /<queryType>/<storeName>/<subpath>
+// queryType can be app or store
+func isQueryStoreWithProof(path string) bool {
+	if !strings.HasPrefix(path, "/") {
+		return false
+	}
+	paths := strings.SplitN(path[1:], "/", 3)
+	if len(paths) != 3 {
+		return false
+	}
+
+	if store.RequireProof("/" + paths[2]) {
+		return true
+	}
+	return false
+}

client/flags.go

@@ -58,6 +58,7 @@ func PostCommands(cmds ...*cobra.Command) []*cobra.Command {
 		c.Flags().Bool(FlagAsync, false, "broadcast transactions asynchronously")
 		c.Flags().Bool(FlagJson, false, "return output in json format")
 		c.Flags().Bool(FlagPrintResponse, true, "return tx response (only works with async = false)")
+		c.Flags().Bool(FlagTrustNode, true, "Don't verify proofs for query responses")
 	}
 	return cmds
 }