From fe8db295e761cf92d646ff7a5fc25b765d75c6bc Mon Sep 17 00:00:00 2001
From: Aayush Rajasekaran <arajasek94@gmail.com>
Date: Tue, 25 Feb 2020 15:17:15 -0800
Subject: [PATCH] Re: #1290: Add a lotus wallet verify API and CLI command

- The command takes an address, message, and signature, and returns true if the sig is valid
---
 api/api_full.go          |  1 +
 api/apistruct/struct.go  |  5 ++++
 cli/cmd.go               | 14 +++++++++++
 cli/wallet.go            | 51 ++++++++++++++++++++++++++++++++++++++++
 cmd/lotus/main.go        |  7 +++++-
 node/impl/full/wallet.go |  5 ++++
 6 files changed, 82 insertions(+), 1 deletion(-)

diff --git a/api/api_full.go b/api/api_full.go
index ee2628806..3bb1b6ccf 100644
--- a/api/api_full.go
+++ b/api/api_full.go
@@ -71,6 +71,7 @@ type FullNode interface {
 	WalletBalance(context.Context, address.Address) (types.BigInt, error)
 	WalletSign(context.Context, address.Address, []byte) (*types.Signature, error)
 	WalletSignMessage(context.Context, address.Address, *types.Message) (*types.SignedMessage, error)
+	WalletVerify(context.Context, address.Address, []byte, *types.Signature) bool
 	WalletDefaultAddress(context.Context) (address.Address, error)
 	WalletSetDefault(context.Context, address.Address) error
 	WalletExport(context.Context, address.Address) (*types.KeyInfo, error)
diff --git a/api/apistruct/struct.go b/api/apistruct/struct.go
index 52b862be9..e51b5f577 100644
--- a/api/apistruct/struct.go
+++ b/api/apistruct/struct.go
@@ -83,6 +83,7 @@ type FullNodeStruct struct {
 		WalletBalance        func(context.Context, address.Address) (types.BigInt, error)                         `perm:"read"`
 		WalletSign           func(context.Context, address.Address, []byte) (*types.Signature, error)             `perm:"sign"`
 		WalletSignMessage    func(context.Context, address.Address, *types.Message) (*types.SignedMessage, error) `perm:"sign"`
+		WalletVerify         func(context.Context, address.Address, []byte, *types.Signature) bool                `perm:"read"`
 		WalletDefaultAddress func(context.Context) (address.Address, error)                                       `perm:"write"`
 		WalletSetDefault     func(context.Context, address.Address) error                                         `perm:"admin"`
 		WalletExport         func(context.Context, address.Address) (*types.KeyInfo, error)                       `perm:"admin"`
@@ -311,6 +312,10 @@ func (c *FullNodeStruct) WalletSignMessage(ctx context.Context, k address.Addres
 	return c.Internal.WalletSignMessage(ctx, k, msg)
 }
 
+func (c *FullNodeStruct) WalletVerify(ctx context.Context, k address.Address, msg []byte, sig *types.Signature) bool {
+	return c.Internal.WalletVerify(ctx, k, msg, sig)
+}
+
 func (c *FullNodeStruct) WalletDefaultAddress(ctx context.Context) (address.Address, error) {
 	return c.Internal.WalletDefaultAddress(ctx)
 }
diff --git a/cli/cmd.go b/cli/cmd.go
index f8eefe208..ac3811d0f 100644
--- a/cli/cmd.go
+++ b/cli/cmd.go
@@ -28,6 +28,20 @@ const (
 	metadataTraceConetxt = "traceContext"
 )
 
+// custom CLI error
+
+type ErrCmdFailed struct {
+	msg string
+}
+
+func (e *ErrCmdFailed) Error() string {
+	return e.msg
+}
+
+func NewCliError(s string) error {
+	return &ErrCmdFailed{s}
+}
+
 // ApiConnector returns API instance
 type ApiConnector func() api.FullNode
 
diff --git a/cli/wallet.go b/cli/wallet.go
index 40ab3a952..dab804af8 100644
--- a/cli/wallet.go
+++ b/cli/wallet.go
@@ -25,6 +25,7 @@ var walletCmd = &cli.Command{
 		walletGetDefault,
 		walletSetDefault,
 		walletSign,
+		walletVerify,
 	},
 }
 
@@ -277,3 +278,53 @@ var walletSign = &cli.Command{
 		return nil
 	},
 }
+
+var walletVerify = &cli.Command{
+	Name:      "verify",
+	Usage:     "verify the signature of a message",
+	ArgsUsage: "<signing address> <hexMessage> <signature>",
+	Action: func(cctx *cli.Context) error {
+		api, closer, err := GetFullNodeAPI(cctx)
+		if err != nil {
+			return err
+		}
+		defer closer()
+		ctx := ReqContext(cctx)
+
+		if !cctx.Args().Present() || cctx.NArg() != 3 {
+			return fmt.Errorf("must specify signing address, message, and signature to verify")
+		}
+
+		addr, err := address.NewFromString(cctx.Args().First())
+
+		if err != nil {
+			return err
+		}
+
+		msg, err := hex.DecodeString(cctx.Args().Get(1))
+
+		if err != nil {
+			return err
+		}
+
+		sigBytes, err := hex.DecodeString(cctx.Args().Get(2))
+
+		if err != nil {
+			return err
+		}
+
+		sig, err := types.SignatureFromBytes(sigBytes)
+
+		if err != nil {
+			return err
+		}
+
+		if api.WalletVerify(ctx, addr, msg, &sig) {
+			fmt.Println("valid")
+			return nil
+		} else {
+			fmt.Println("invalid")
+			return NewCliError("CLI Verify called with invalid signature")
+		}
+	},
+}
diff --git a/cmd/lotus/main.go b/cmd/lotus/main.go
index e040d397e..6eeec7509 100644
--- a/cmd/lotus/main.go
+++ b/cmd/lotus/main.go
@@ -73,7 +73,12 @@ func main() {
 			Code:    trace.StatusCodeFailedPrecondition,
 			Message: err.Error(),
 		})
-		log.Warnf("%+v", err)
+		_, ok := err.(*lcli.ErrCmdFailed)
+		if ok {
+			log.Debugf("%+v", err)
+		} else {
+			log.Warnf("%+v", err)
+		}
 		os.Exit(1)
 	}
 }
diff --git a/node/impl/full/wallet.go b/node/impl/full/wallet.go
index b30a55f38..ad5fe876c 100644
--- a/node/impl/full/wallet.go
+++ b/node/impl/full/wallet.go
@@ -2,6 +2,7 @@ package full
 
 import (
 	"context"
+	"github.com/filecoin-project/lotus/lib/sigs"
 
 	"github.com/filecoin-project/go-address"
 	"github.com/filecoin-project/lotus/chain/stmgr"
@@ -53,6 +54,10 @@ func (a *WalletAPI) WalletSignMessage(ctx context.Context, k address.Address, ms
 	}, nil
 }
 
+func (a *WalletAPI) WalletVerify(ctx context.Context, k address.Address, msg []byte, sig *types.Signature) bool {
+	return sigs.Verify(sig, k, msg) == nil
+}
+
 func (a *WalletAPI) WalletDefaultAddress(ctx context.Context) (address.Address, error) {
 	return a.Wallet.GetDefault()
 }