grafana/pkg/plugins/manager/signature/manifest.go
Will Browne a221e1d226
Plugins: Standardize Golang enum naming convention (#69449)
* standardize enum pattern

* fix up
2023-06-08 12:21:19 +02:00

349 lines
9.7 KiB
Go

package signature
import (
"bytes"
"context"
"crypto/sha256"
"encoding/hex"
"encoding/json"
"errors"
"fmt"
"io"
"net/url"
"os"
"path"
"path/filepath"
"runtime"
"strings"
"github.com/ProtonMail/go-crypto/openpgp"
"github.com/ProtonMail/go-crypto/openpgp/clearsign"
"github.com/ProtonMail/go-crypto/openpgp/packet"
"github.com/gobwas/glob"
"github.com/grafana/grafana/pkg/plugins"
"github.com/grafana/grafana/pkg/plugins/config"
"github.com/grafana/grafana/pkg/plugins/log"
"github.com/grafana/grafana/pkg/setting"
)
var (
runningWindows = runtime.GOOS == "windows"
// toSlash is filepath.ToSlash, but can be overwritten in tests path separators cross-platform
toSlash = filepath.ToSlash
// fromSlash is filepath.FromSlash, but can be overwritten in tests path separators cross-platform
fromSlash = filepath.FromSlash
)
// PluginManifest holds details for the file manifest
type PluginManifest struct {
Plugin string `json:"plugin"`
Version string `json:"version"`
KeyID string `json:"keyId"`
Time int64 `json:"time"`
Files map[string]string `json:"files"`
// V2 supported fields
ManifestVersion string `json:"manifestVersion"`
SignatureType plugins.SignatureType `json:"signatureType"`
SignedByOrg string `json:"signedByOrg"`
SignedByOrgName string `json:"signedByOrgName"`
RootURLs []string `json:"rootUrls"`
}
func (m *PluginManifest) isV2() bool {
return strings.HasPrefix(m.ManifestVersion, "2.")
}
type Signature struct {
log log.Logger
kr plugins.KeyRetriever
}
var _ plugins.SignatureCalculator = &Signature{}
func ProvideService(cfg *config.Cfg, kr plugins.KeyRetriever) *Signature {
return &Signature{
log: log.New("plugin.signature"),
kr: kr,
}
}
// readPluginManifest attempts to read and verify the plugin manifest
// if any error occurs or the manifest is not valid, this will return an error
func (s *Signature) readPluginManifest(ctx context.Context, body []byte) (*PluginManifest, error) {
block, _ := clearsign.Decode(body)
if block == nil {
return nil, errors.New("unable to decode manifest")
}
// Convert to a well typed object
var manifest PluginManifest
err := json.Unmarshal(block.Plaintext, &manifest)
if err != nil {
return nil, fmt.Errorf("%v: %w", "Error parsing manifest JSON", err)
}
if err = s.validateManifest(ctx, manifest, block); err != nil {
return nil, err
}
return &manifest, nil
}
func (s *Signature) Calculate(ctx context.Context, src plugins.PluginSource, plugin plugins.FoundPlugin) (plugins.Signature, error) {
if defaultSignature, exists := src.DefaultSignature(ctx); exists {
return defaultSignature, nil
}
fsFiles, err := plugin.FS.Files()
if err != nil {
return plugins.Signature{}, fmt.Errorf("files: %w", err)
}
if len(fsFiles) == 0 {
s.log.Warn("No plugin file information in directory", "pluginID", plugin.JSONData.ID)
return plugins.Signature{
Status: plugins.SignatureStatusInvalid,
}, nil
}
f, err := plugin.FS.Open("MANIFEST.txt")
if err != nil {
if errors.Is(err, plugins.ErrFileNotExist) {
s.log.Debug("Could not find a MANIFEST.txt", "id", plugin.JSONData.ID, "err", err)
return plugins.Signature{
Status: plugins.SignatureStatusUnsigned,
}, nil
}
s.log.Debug("Could not open MANIFEST.txt", "id", plugin.JSONData.ID, "err", err)
return plugins.Signature{
Status: plugins.SignatureStatusInvalid,
}, nil
}
defer func() {
if f == nil {
return
}
if err = f.Close(); err != nil {
s.log.Warn("Failed to close plugin MANIFEST file", "err", err)
}
}()
byteValue, err := io.ReadAll(f)
if err != nil || len(byteValue) < 10 {
s.log.Debug("MANIFEST.TXT is invalid", "id", plugin.JSONData.ID)
return plugins.Signature{
Status: plugins.SignatureStatusUnsigned,
}, nil
}
manifest, err := s.readPluginManifest(ctx, byteValue)
if err != nil {
s.log.Warn("Plugin signature invalid", "id", plugin.JSONData.ID, "err", err)
return plugins.Signature{
Status: plugins.SignatureStatusInvalid,
}, nil
}
if !manifest.isV2() {
return plugins.Signature{
Status: plugins.SignatureStatusInvalid,
}, nil
}
// Make sure the versions all match
if manifest.Plugin != plugin.JSONData.ID || manifest.Version != plugin.JSONData.Info.Version {
return plugins.Signature{
Status: plugins.SignatureStatusModified,
}, nil
}
// Validate that plugin is running within defined root URLs
if len(manifest.RootURLs) > 0 {
if match, err := urlMatch(manifest.RootURLs, setting.AppUrl, manifest.SignatureType); err != nil {
s.log.Warn("Could not verify if root URLs match", "plugin", plugin.JSONData.ID, "rootUrls", manifest.RootURLs)
return plugins.Signature{}, err
} else if !match {
s.log.Warn("Could not find root URL that matches running application URL", "plugin", plugin.JSONData.ID,
"appUrl", setting.AppUrl, "rootUrls", manifest.RootURLs)
return plugins.Signature{
Status: plugins.SignatureStatusInvalid,
}, nil
}
}
manifestFiles := make(map[string]struct{}, len(manifest.Files))
// Verify the manifest contents
for p, hash := range manifest.Files {
err = verifyHash(s.log, plugin, p, hash)
if err != nil {
return plugins.Signature{
Status: plugins.SignatureStatusModified,
}, nil
}
manifestFiles[p] = struct{}{}
}
// Track files missing from the manifest
var unsignedFiles []string
for _, f := range fsFiles {
// Ensure slashes are used, because MANIFEST.txt always uses slashes regardless of the filesystem
f = toSlash(f)
// Ignoring unsigned Chromium debug.log so it doesn't invalidate the signature for Renderer plugin running on Windows
if runningWindows && plugin.JSONData.Type == plugins.TypeRenderer && f == "chrome-win/debug.log" {
continue
}
if f == "MANIFEST.txt" {
continue
}
if _, exists := manifestFiles[f]; !exists {
unsignedFiles = append(unsignedFiles, f)
}
}
if len(unsignedFiles) > 0 {
s.log.Warn("The following files were not included in the signature", "plugin", plugin.JSONData.ID, "files", unsignedFiles)
return plugins.Signature{
Status: plugins.SignatureStatusModified,
}, nil
}
s.log.Debug("Plugin signature valid", "id", plugin.JSONData.ID)
return plugins.Signature{
Status: plugins.SignatureStatusValid,
Type: manifest.SignatureType,
SigningOrg: manifest.SignedByOrgName,
}, nil
}
func verifyHash(mlog log.Logger, plugin plugins.FoundPlugin, path, hash string) error {
path = fromSlash(path)
// nolint:gosec
// We can ignore the gosec G304 warning on this one because `path` is based
// on the path provided in a manifest file for a plugin and not user input.
f, err := plugin.FS.Open(path)
if err != nil {
if os.IsPermission(err) {
mlog.Warn("Could not open plugin file due to lack of permissions", "plugin", plugin.JSONData.ID, "path", path)
return errors.New("permission denied when attempting to read plugin file")
}
mlog.Warn("Plugin file listed in the manifest was not found", "plugin", plugin.JSONData.ID, "path", path)
return errors.New("plugin file listed in the manifest was not found")
}
defer func() {
if err := f.Close(); err != nil {
mlog.Warn("Failed to close plugin file", "path", path, "err", err)
}
}()
h := sha256.New()
if _, err := io.Copy(h, f); err != nil {
return errors.New("could not calculate plugin file checksum")
}
sum := hex.EncodeToString(h.Sum(nil))
if sum != hash {
mlog.Warn("Plugin file checksum does not match signature checksum", "plugin", plugin.JSONData.ID, "path", path)
return errors.New("plugin file checksum does not match signature checksum")
}
return nil
}
func urlMatch(specs []string, target string, signatureType plugins.SignatureType) (bool, error) {
targetURL, err := url.Parse(target)
if err != nil {
return false, err
}
for _, spec := range specs {
specURL, err := url.Parse(spec)
if err != nil {
return false, err
}
if specURL.Scheme == targetURL.Scheme && specURL.Host == targetURL.Host &&
path.Clean(specURL.RequestURI()) == path.Clean(targetURL.RequestURI()) {
return true, nil
}
if signatureType != plugins.SignatureTypePrivateGlob {
continue
}
sp, err := glob.Compile(spec, '/', '.')
if err != nil {
return false, err
}
if match := sp.Match(target); match {
return true, nil
}
}
return false, nil
}
type invalidFieldErr struct {
field string
}
func (r invalidFieldErr) Error() string {
return fmt.Sprintf("valid manifest field %s is required", r.field)
}
func (s *Signature) validateManifest(ctx context.Context, m PluginManifest, block *clearsign.Block) error {
if len(m.Plugin) == 0 {
return invalidFieldErr{field: "plugin"}
}
if len(m.Version) == 0 {
return invalidFieldErr{field: "version"}
}
if len(m.KeyID) == 0 {
return invalidFieldErr{field: "keyId"}
}
if m.Time == 0 {
return invalidFieldErr{field: "time"}
}
if len(m.Files) == 0 {
return invalidFieldErr{field: "files"}
}
if m.isV2() {
if len(m.SignedByOrg) == 0 {
return invalidFieldErr{field: "signedByOrg"}
}
if len(m.SignedByOrgName) == 0 {
return invalidFieldErr{field: "signedByOrgName"}
}
if !m.SignatureType.IsValid() {
return fmt.Errorf("%s is not a valid signature type", m.SignatureType)
}
}
return s.Verify(ctx, m.KeyID, block)
}
func (s *Signature) Verify(ctx context.Context, keyID string, block *clearsign.Block) error {
publicKey, err := s.kr.GetPublicKey(ctx, keyID)
if err != nil {
return err
}
keyring, err := openpgp.ReadArmoredKeyRing(bytes.NewBufferString(publicKey))
if err != nil {
return fmt.Errorf("%v: %w", "failed to parse public key", err)
}
if _, err = openpgp.CheckDetachedSignature(keyring,
bytes.NewBuffer(block.Bytes),
block.ArmoredSignature.Body, &packet.Config{}); err != nil {
return fmt.Errorf("failed to check signature: %w", err)
}
return nil
}