feat: verify by checksum and remove if invalid

.gitignore

@@ -31,6 +31,7 @@ frontend/qml/*.qmlc
 /bridge_*_*.tgz
 /ie_*_*.tgz
 /versioner
+/hasher
 cmd/Desktop-Bridge/deploy
 cmd/Import-Export/deploy
 internal/frontend/qt*/moc.cpp

Makefile

@@ -7,7 +7,7 @@ TARGET_CMD?=Desktop-Bridge
 TARGET_OS?=${GOOS}
 
 ## Build
-.PHONY: build build-ie build-nogui build-ie-nogui build-launcher build-launcher-ie  versioner
+.PHONY: build build-ie build-nogui build-ie-nogui build-launcher build-launcher-ie  versioner hasher
 
 # Keep version hardcoded so app build works also without Git repository.
 BRIDGE_APP_VERSION?=1.5.5+git
@@ -87,7 +87,10 @@ build-launcher-ie:
 	go build -ldflags="-X 'main.ConfigName=importExport' -X 'main.ExeName=Import-Export'" -o launcher-ie cmd/launcher/main.go
 
 versioner:
-	go build ${BUILD_FLAGS} ${GO_LDFLAGS} -o versioner cmd/versioner/main.go
+	go build ${BUILD_FLAGS} ${GO_LDFLAGS} -o versioner utils/versioner/main.go
+
+hasher:
+	go build -o hasher utils/hasher/main.go
 
 ${TGZ_TARGET}: ${DEPLOY_DIR}/${TARGET_OS}
 	rm -f $@

cmd/launcher/main.go

@@ -149,7 +149,12 @@ func getPathToExecutable(name string, versioner *versioner.Versioner, kr *crypto
 		vlog := logrus.WithField("version", version)
 
 		if err := version.VerifyFiles(kr); err != nil {
-			vlog.WithError(err).Error("Failed to verify files")
+			vlog.WithError(err).Error("Files failed verification and will be removed")
+
+			if err := version.Remove(); err != nil {
+				vlog.WithError(err).Error("Failed to remove files")
+			}
+
 			continue
 		}
 

internal/versioner/version.go

@@ -18,14 +18,19 @@
 package versioner
 
 import (
+	"bytes"
+	"errors"
 	"io/ioutil"
 	"os"
 	"path/filepath"
 
 	"github.com/Masterminds/semver/v3"
 	"github.com/ProtonMail/gopenpgp/v2/crypto"
+	"github.com/ProtonMail/proton-bridge/pkg/sum"
 )
 
+const sumFile = ".sum"
+
 type Version struct {
 	version *semver.Version
 	path    string
@@ -47,31 +52,34 @@ func (v Versions) Swap(i, j int) {
 
 // VerifyFiles verifies all files in the version directory.
 func (v *Version) VerifyFiles(kr *crypto.KeyRing) error {
-	return filepath.Walk(v.path, func(path string, info os.FileInfo, err error) error {
-		if err != nil {
-			return err
-		}
+	fileBytes, err := ioutil.ReadFile(filepath.Join(v.path, sumFile)) // nolint[gosec]
+	if err != nil {
+		return err
+	}
 
-		if filepath.Ext(path) == ".sig" || info.IsDir() {
-			return nil
-		}
+	sigBytes, err := ioutil.ReadFile(filepath.Join(v.path, sumFile+".sig")) // nolint[gosec]
+	if err != nil {
+		return err
+	}
 
-		fileBytes, err := ioutil.ReadFile(path) // nolint[gosec]
-		if err != nil {
-			return err
-		}
+	if err := kr.VerifyDetached(
+		crypto.NewPlainMessage(fileBytes),
+		crypto.NewPGPSignature(sigBytes),
+		crypto.GetUnixTime(),
+	); err != nil {
+		return err
+	}
 
-		sigBytes, err := ioutil.ReadFile(path + ".sig") // nolint[gosec]
-		if err != nil {
-			return err
-		}
+	sum, err := sum.RecursiveSum(v.path, sumFile)
+	if err != nil {
+		return err
+	}
 
-		return kr.VerifyDetached(
-			crypto.NewPlainMessage(fileBytes),
-			crypto.NewPGPSignature(sigBytes),
-			crypto.GetUnixTime(),
-		)
-	})
+	if !bytes.Equal(sum, fileBytes) {
+		return errors.New("sum mismatch")
+	}
+
+	return nil
 }
 
 // GetExecutable returns the full path to the executable of the given version.
@@ -85,3 +93,8 @@ func (v *Version) GetExecutable(name string) (string, error) {
 
 	return exe, nil
 }
+
+// Remove removes this version directory.
+func (v *Version) Remove() error {
+	return os.RemoveAll(v.path)
+}

internal/versioner/version_test.go

@@ -26,6 +26,7 @@ import (
 
 	"github.com/Masterminds/semver/v3"
 	"github.com/ProtonMail/gopenpgp/v2/crypto"
+	"github.com/ProtonMail/proton-bridge/pkg/sum"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -39,12 +40,12 @@ func TestVerifyFiles(t *testing.T) {
 		path:    tempDir,
 	}
 
-	kr := createSignedFiles(t,
-		filepath.Join(tempDir, "f1.txt"),
-		filepath.Join(tempDir, "f2.png"),
-		filepath.Join(tempDir, "f3.dat"),
-		filepath.Join(tempDir, "sub", "f4.tar"),
-		filepath.Join(tempDir, "sub", "f5.tgz"),
+	kr := createSignedFiles(t, tempDir,
+		"f1.txt",
+		"f2.png",
+		"f3.dat",
+		filepath.Join("sub", "f4.tar"),
+		filepath.Join("sub", "f5.tgz"),
 	)
 
 	assert.NoError(t, version.VerifyFiles(kr))
@@ -59,12 +60,12 @@ func TestVerifyWithBadFile(t *testing.T) {
 		path:    tempDir,
 	}
 
-	kr := createSignedFiles(t,
-		filepath.Join(tempDir, "f1.txt"),
-		filepath.Join(tempDir, "f2.png"),
-		filepath.Join(tempDir, "f3.bad"),
-		filepath.Join(tempDir, "sub", "f4.tar"),
-		filepath.Join(tempDir, "sub", "f5.tgz"),
+	kr := createSignedFiles(t, tempDir,
+		"f1.txt",
+		"f2.png",
+		"f3.bad",
+		filepath.Join("sub", "f4.tar"),
+		filepath.Join("sub", "f5.tgz"),
 	)
 
 	badKeyRing := makeKeyRing(t)
@@ -82,12 +83,12 @@ func TestVerifyWithBadSubFile(t *testing.T) {
 		path:    tempDir,
 	}
 
-	kr := createSignedFiles(t,
-		filepath.Join(tempDir, "f1.txt"),
-		filepath.Join(tempDir, "f2.png"),
-		filepath.Join(tempDir, "f3.dat"),
-		filepath.Join(tempDir, "sub", "f4.tar"),
-		filepath.Join(tempDir, "sub", "f5.bad"),
+	kr := createSignedFiles(t, tempDir,
+		"f1.txt",
+		"f2.png",
+		"f3.dat",
+		filepath.Join("sub", "f4.tar"),
+		filepath.Join("sub", "f5.bad"),
 	)
 
 	badKeyRing := makeKeyRing(t)
@@ -96,15 +97,24 @@ func TestVerifyWithBadSubFile(t *testing.T) {
 	assert.Error(t, version.VerifyFiles(kr))
 }
 
-func createSignedFiles(t *testing.T, paths ...string) *crypto.KeyRing {
+func createSignedFiles(t *testing.T, root string, paths ...string) *crypto.KeyRing {
 	kr := makeKeyRing(t)
 
 	for _, path := range paths {
-		require.NoError(t, os.MkdirAll(filepath.Dir(path), 0700))
-		makeFile(t, path)
-		signFile(t, path, kr)
+		makeFile(t, filepath.Join(root, path))
 	}
 
+	sum, err := sum.RecursiveSum(root, "")
+	require.NoError(t, err)
+
+	sumFile, err := os.Create(filepath.Join(root, sumFile))
+	require.NoError(t, err)
+
+	_, err = sumFile.Write(sum)
+	require.NoError(t, err)
+
+	signFile(t, sumFile.Name(), kr)
+
 	return kr
 }
 
@@ -119,6 +129,8 @@ func makeKeyRing(t *testing.T) *crypto.KeyRing {
 }
 
 func makeFile(t *testing.T, path string) {
+	require.NoError(t, os.MkdirAll(filepath.Dir(path), 0700))
+
 	f, err := os.Create(path)
 	require.NoError(t, err)
 

internal/versioner/versioner_remove_test.go

@@ -0,0 +1,52 @@
+// Copyright (c) 2020 Proton Technologies AG
+//
+// This file is part of ProtonMail Bridge.
+//
+// ProtonMail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// ProtonMail Bridge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with ProtonMail Bridge.  If not, see <https://www.gnu.org/licenses/>.
+
+// +build !darwin
+
+package versioner
+
+import (
+	"io/ioutil"
+	"path/filepath"
+	"testing"
+
+	"github.com/Masterminds/semver/v3"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// RemoveOldVersions is a noop on darwin; we don't test it there.
+
+func TestRemoveOldVersions(t *testing.T) {
+	updates, err := ioutil.TempDir("", "updates")
+	require.NoError(t, err)
+
+	v := newTestVersioner(t, "myCoolApp", updates, "2.3.4-beta", "2.3.4", "2.3.5", "2.4.0")
+
+	allVersions, err := v.ListVersions()
+	require.NoError(t, err)
+	require.Len(t, allVersions, 4)
+
+	assert.NoError(t, v.RemoveOldVersions())
+
+	cleanedVersions, err := v.ListVersions()
+	assert.NoError(t, err)
+	assert.Len(t, cleanedVersions, 1)
+
+	assert.Equal(t, semver.MustParse("2.4.0"), cleanedVersions[0].version)
+	assert.Equal(t, filepath.Join(updates, "2.4.0"), cleanedVersions[0].path)
+}

internal/versioner/versioner_test.go

@@ -50,26 +50,6 @@ func TestListVersions(t *testing.T) {
 	assert.Equal(t, filepath.Join(updates, "2.3.4-beta"), versions[3].path)
 }
 
-func TestRemoveOldVersions(t *testing.T) {
-	updates, err := ioutil.TempDir("", "updates")
-	require.NoError(t, err)
-
-	v := newTestVersioner(t, "myCoolApp", updates, "2.3.4-beta", "2.3.4", "2.3.5", "2.4.0")
-
-	allVersions, err := v.ListVersions()
-	require.NoError(t, err)
-	require.Len(t, allVersions, 4)
-
-	assert.NoError(t, v.RemoveOldVersions())
-
-	cleanedVersions, err := v.ListVersions()
-	assert.NoError(t, err)
-	assert.Len(t, cleanedVersions, 1)
-
-	assert.Equal(t, semver.MustParse("2.4.0"), cleanedVersions[0].version)
-	assert.Equal(t, filepath.Join(updates, "2.4.0"), cleanedVersions[0].path)
-}
-
 func newTestVersioner(t *testing.T, exeName, updates string, versions ...string) *Versioner {
 	for _, version := range versions {
 		makeDummyVersionDirectory(t, exeName, updates, version)

pkg/sum/sum.go

@@ -0,0 +1,66 @@
+// Copyright (c) 2020 Proton Technologies AG
+//
+// This file is part of ProtonMail Bridge.
+//
+// ProtonMail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// ProtonMail Bridge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with ProtonMail Bridge.  If not, see <https://www.gnu.org/licenses/>.
+
+package sum
+
+import (
+	"crypto/sha512"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// RecursiveSum computes the sha512 sum of all files in the root directory and descendents.
+// If a skipFile is provided (e.g. the path of a checksum file relative to rootDir), it (and its signature) is ignored.
+func RecursiveSum(rootDir, skipFile string) ([]byte, error) {
+	hash := sha512.New()
+
+	if err := filepath.Walk(rootDir, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		if info.IsDir() {
+			return nil
+		}
+
+		// The hashfile itself isn't included in the hash.
+		if path == filepath.Join(rootDir, skipFile) || path == filepath.Join(rootDir, skipFile+".sig") {
+			return nil
+		}
+
+		if _, err := hash.Write([]byte(strings.TrimPrefix(path, rootDir))); err != nil {
+			return err
+		}
+
+		f, err := os.Open(path) // nolint[gosec]
+		if err != nil {
+			return err
+		}
+
+		if _, err := io.Copy(hash, f); err != nil {
+			return err
+		}
+
+		return nil
+	}); err != nil {
+		return nil, err
+	}
+
+	return hash.Sum([]byte{}), nil
+}

pkg/sum/sum_test.go

@@ -0,0 +1,112 @@
+// Copyright (c) 2020 Proton Technologies AG
+//
+// This file is part of ProtonMail Bridge.
+//
+// ProtonMail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// ProtonMail Bridge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with ProtonMail Bridge.  If not, see <https://www.gnu.org/licenses/>.
+
+package sum
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestRecursiveSum(t *testing.T) {
+	tempDir, err := ioutil.TempDir("", "verify-test")
+	require.NoError(t, err)
+
+	createFiles(t, tempDir,
+		filepath.Join("a", "1"),
+		filepath.Join("a", "2"),
+		filepath.Join("b", "3"),
+		filepath.Join("b", "4"),
+		filepath.Join("b", "c", "5"),
+		filepath.Join("b", "c", "6"),
+	)
+
+	sumOriginal := sum(t, tempDir)
+
+	// Renaming files should produce a different checksum.
+	require.NoError(t, os.Rename(filepath.Join(tempDir, "a", "1"), filepath.Join(tempDir, "a", "11")))
+	sumRenamed := sum(t, tempDir)
+	require.NotEqual(t, sumOriginal, sumRenamed)
+
+	// Reverting to the original name should produce the same checksum again.
+	require.NoError(t, os.Rename(filepath.Join(tempDir, "a", "11"), filepath.Join(tempDir, "a", "1")))
+	require.Equal(t, sumOriginal, sum(t, tempDir))
+
+	// Moving files should produce a different checksum.
+	require.NoError(t, os.Rename(filepath.Join(tempDir, "a", "1"), filepath.Join(tempDir, "1")))
+	sumMoved := sum(t, tempDir)
+	require.NotEqual(t, sumOriginal, sumMoved)
+
+	// Moving files back to their original location should produce the same checksum again.
+	require.NoError(t, os.Rename(filepath.Join(tempDir, "1"), filepath.Join(tempDir, "a", "1")))
+	require.Equal(t, sumOriginal, sum(t, tempDir))
+
+	// Changing file data should produce a different checksum.
+	originalData := modifyFile(t, filepath.Join(tempDir, "a", "1"), []byte("something"))
+	require.NotEqual(t, sumOriginal, sum(t, tempDir))
+
+	// Reverting file data should produce the original checksum.
+	modifyFile(t, filepath.Join(tempDir, "a", "1"), originalData)
+	require.Equal(t, sumOriginal, sum(t, tempDir))
+}
+
+func createFiles(t *testing.T, root string, paths ...string) {
+	for _, path := range paths {
+		makeFile(t, filepath.Join(root, path))
+	}
+}
+
+func makeFile(t *testing.T, path string) {
+	require.NoError(t, os.MkdirAll(filepath.Dir(path), 0700))
+
+	f, err := os.Create(path)
+	require.NoError(t, err)
+
+	_, err = f.WriteString(path)
+	require.NoError(t, err)
+
+	require.NoError(t, f.Close())
+}
+
+func sum(t *testing.T, path string) []byte {
+	sum, err := RecursiveSum(path, "")
+	require.NoError(t, err)
+
+	return sum
+}
+
+func modifyFile(t *testing.T, path string, data []byte) []byte {
+	r, err := os.Open(path)
+	require.NoError(t, err)
+
+	b, err := ioutil.ReadAll(r)
+	require.NoError(t, err)
+	require.NoError(t, r.Close())
+
+	f, err := os.Create(path)
+	require.NoError(t, err)
+
+	_, err = f.Write(data)
+	require.NoError(t, err)
+	require.NoError(t, f.Close())
+
+	return b
+}

utils/hasher/main.go

@@ -0,0 +1,62 @@
+// Copyright (c) 2020 Proton Technologies AG
+//
+// This file is part of ProtonMail Bridge.
+//
+// ProtonMail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// ProtonMail Bridge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with ProtonMail Bridge.  If not, see <https://www.gnu.org/licenses/>.
+
+package main
+
+import (
+	"os"
+
+	"github.com/ProtonMail/proton-bridge/pkg/sum"
+	"github.com/sirupsen/logrus"
+	"github.com/urfave/cli/v2"
+)
+
+func main() {
+	if err := createApp().Run(os.Args); err != nil {
+		logrus.Fatal(err)
+	}
+}
+
+func createApp() *cli.App { // nolint[funlen]
+	app := cli.NewApp()
+
+	app.Name = "hasher"
+	app.Usage = "Generate the recursive hash of a directory"
+	app.Action = computeSum
+	app.Flags = []cli.Flag{
+		&cli.StringFlag{
+			Name:     "root",
+			Usage:    "The root directory from which to begin recursive hashing",
+			Required: true,
+		},
+	}
+
+	return app
+}
+
+func computeSum(c *cli.Context) error {
+	b, err := sum.RecursiveSum(c.String("root"), "")
+	if err != nil {
+		return err
+	}
+
+	if _, err := c.App.Writer.Write(b); err != nil {
+		return err
+	}
+
+	return nil
+}