From c49eb86a2ecbc95e59ab14fd362ae370e5fa9bd9 Mon Sep 17 00:00:00 2001
From: Evgenii Stratonikov <evgeniy@nspcc.ru>
Date: Thu, 17 Dec 2020 15:41:53 +0300
Subject: [PATCH] cli: allow to calculate contract hash before deployment

---
 cli/contract_test.go                | 55 +++++++++++++++++++++++++++++
 cli/smartcontract/smart_contract.go | 44 +++++++++++++++++++++++
 2 files changed, 99 insertions(+)

diff --git a/cli/contract_test.go b/cli/contract_test.go
index 994216ae7..4db8aca80 100644
--- a/cli/contract_test.go
+++ b/cli/contract_test.go
@@ -9,14 +9,63 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/nspcc-dev/neo-go/internal/random"
 	"github.com/nspcc-dev/neo-go/pkg/config"
+	"github.com/nspcc-dev/neo-go/pkg/core/state"
+	"github.com/nspcc-dev/neo-go/pkg/encoding/address"
 	"github.com/nspcc-dev/neo-go/pkg/encoding/fixedn"
 	"github.com/nspcc-dev/neo-go/pkg/rpc/response/result"
+	"github.com/nspcc-dev/neo-go/pkg/smartcontract/nef"
 	"github.com/nspcc-dev/neo-go/pkg/util"
 	"github.com/nspcc-dev/neo-go/pkg/vm"
 	"github.com/stretchr/testify/require"
 )
 
+func TestCalcHash(t *testing.T) {
+	e := newExecutor(t, false)
+	defer e.Close(t)
+
+	nefPath := "./testdata/verify.nef"
+	src, err := ioutil.ReadFile(nefPath)
+	require.NoError(t, err)
+	nefF, err := nef.FileFromBytes(src)
+	require.NoError(t, err)
+	sender := random.Uint160()
+
+	cmd := []string{"neo-go", "contract", "calc-hash"}
+	t.Run("no sender", func(t *testing.T) {
+		e.RunWithError(t, append(cmd, "--in", nefPath)...)
+	})
+	t.Run("no nef file", func(t *testing.T) {
+		e.RunWithError(t, append(cmd, "--sender", sender.StringLE())...)
+	})
+	t.Run("invalid path", func(t *testing.T) {
+		e.RunWithError(t, append(cmd, "--sender", sender.StringLE(),
+			"--in", "./testdata/verify.nef123")...)
+	})
+	t.Run("invalid file", func(t *testing.T) {
+		p := path.Join(os.TempDir(), "neogo.calchash.verify.nef")
+		defer os.Remove(p)
+		require.NoError(t, ioutil.WriteFile(p, src[:4], os.ModePerm))
+		e.RunWithError(t, append(cmd, "--sender", sender.StringLE(), "--in", p)...)
+	})
+
+	cmd = append(cmd, "--in", nefPath)
+	expected := state.CreateContractHash(sender, nefF.Script)
+	t.Run("valid, uint160", func(t *testing.T) {
+		e.Run(t, append(cmd, "--sender", sender.StringLE())...)
+		e.checkNextLine(t, expected.StringLE())
+	})
+	t.Run("valid, uint160 with 0x", func(t *testing.T) {
+		e.Run(t, append(cmd, "--sender", "0x"+sender.StringLE())...)
+		e.checkNextLine(t, expected.StringLE())
+	})
+	t.Run("valid, address", func(t *testing.T) {
+		e.Run(t, append(cmd, "--sender", address.Uint160ToString(sender))...)
+		e.checkNextLine(t, expected.StringLE())
+	})
+}
+
 func TestContractInitAndCompile(t *testing.T) {
 	tmpDir := path.Join(os.TempDir(), "neogo.inittest")
 	require.NoError(t, os.Mkdir(tmpDir, os.ModePerm))
@@ -139,6 +188,12 @@ func TestComlileAndInvokeFunction(t *testing.T) {
 	require.NoError(t, err)
 	e.checkTxPersisted(t)
 
+	t.Run("check calc hash", func(t *testing.T) {
+		e.Run(t, "neo-go", "contract", "calc-hash",
+			"--sender", validatorAddr, "--in", nefName)
+		e.checkNextLine(t, h.StringLE())
+	})
+
 	cmd := []string{"neo-go", "contract", "testinvokefunction",
 		"--rpc-endpoint", "http://" + e.RPC.Addr}
 	t.Run("missing hash", func(t *testing.T) {
diff --git a/cli/smartcontract/smart_contract.go b/cli/smartcontract/smart_contract.go
index bb130466c..c18bdb40b 100644
--- a/cli/smartcontract/smart_contract.go
+++ b/cli/smartcontract/smart_contract.go
@@ -337,6 +337,21 @@ func NewCommands() []cli.Command {
 					},
 				},
 			},
+			{
+				Name:   "calc-hash",
+				Usage:  "calculates hash of a contract after deployment",
+				Action: calcHash,
+				Flags: []cli.Flag{
+					cli.StringFlag{
+						Name:  "sender, s",
+						Usage: "sender script hash or address",
+					},
+					cli.StringFlag{
+						Name:  "in",
+						Usage: "path to NEF file",
+					},
+				},
+			},
 		},
 	}}
 }
@@ -440,6 +455,35 @@ func contractCompile(ctx *cli.Context) error {
 	return nil
 }
 
+func calcHash(ctx *cli.Context) error {
+	s := ctx.String("sender")
+	u, err := address.StringToUint160(s)
+	if err != nil {
+		if strings.HasPrefix(s, "0x") {
+			s = s[2:]
+		}
+		u, err = util.Uint160DecodeStringLE(s)
+		if err != nil {
+			return cli.NewExitError(errors.New("invalid sender: must be either address or Uint160 in LE form"), 1)
+		}
+	}
+
+	p := ctx.String("in")
+	if p == "" {
+		return cli.NewExitError(errors.New("no .nef file was provided"), 1)
+	}
+	f, err := ioutil.ReadFile(p)
+	if err != nil {
+		return cli.NewExitError(fmt.Errorf("can't read .nef file: %w", err), 1)
+	}
+	nefFile, err := nef.FileFromBytes(f)
+	if err != nil {
+		return cli.NewExitError(fmt.Errorf("can't unmarshal .nef file: %w", err), 1)
+	}
+	fmt.Fprintln(ctx.App.Writer, "Contract hash:", state.CreateContractHash(u, nefFile.Script).StringLE())
+	return nil
+}
+
 func testInvokeFunction(ctx *cli.Context) error {
 	return invokeInternal(ctx, false)
 }