grafana/pkg/services/secrets/manager/manager.go

384 lines
10 KiB
Go

package manager
import (
"bytes"
"context"
"crypto/rand"
"encoding/base64"
"errors"
"fmt"
"time"
"github.com/grafana/grafana/pkg/infra/log"
"github.com/grafana/grafana/pkg/infra/usagestats"
"github.com/grafana/grafana/pkg/services/encryption"
"github.com/grafana/grafana/pkg/services/featuremgmt"
"github.com/grafana/grafana/pkg/services/kmsproviders"
"github.com/grafana/grafana/pkg/services/secrets"
"github.com/grafana/grafana/pkg/setting"
"xorm.io/xorm"
)
type SecretsService struct {
store secrets.Store
enc encryption.Internal
settings setting.Provider
usageStats usagestats.Service
currentProviderID secrets.ProviderID
providers map[secrets.ProviderID]secrets.Provider
dataKeyCache map[string]dataKeyCacheItem
log log.Logger
}
func ProvideSecretsService(
store secrets.Store,
kmsProvidersService kmsproviders.Service,
enc encryption.Internal,
settings setting.Provider,
usageStats usagestats.Service,
) (*SecretsService, error) {
providers, err := kmsProvidersService.Provide()
if err != nil {
return nil, err
}
logger := log.New("secrets")
enabled := settings.IsFeatureToggleEnabled(featuremgmt.FlagEnvelopeEncryption)
currentProviderID := readCurrentProviderID(settings)
if _, ok := providers[currentProviderID]; enabled && !ok {
return nil, fmt.Errorf("missing configuration for current encryption provider %s", currentProviderID)
}
if !enabled && currentProviderID != kmsproviders.Default {
logger.Warn("Changing encryption provider requires enabling envelope encryption feature")
}
logger.Debug("Envelope encryption state", "enabled", enabled, "current provider", currentProviderID)
s := &SecretsService{
store: store,
enc: enc,
settings: settings,
usageStats: usageStats,
providers: providers,
currentProviderID: currentProviderID,
dataKeyCache: make(map[string]dataKeyCacheItem),
log: logger,
}
s.registerUsageMetrics()
return s, nil
}
func readCurrentProviderID(settings setting.Provider) secrets.ProviderID {
currentProvider := settings.KeyValue("security", "encryption_provider").MustString(kmsproviders.Default)
if currentProvider == kmsproviders.Legacy {
currentProvider = kmsproviders.Default
}
return secrets.ProviderID(currentProvider)
}
func (s *SecretsService) registerUsageMetrics() {
s.usageStats.RegisterMetricsFunc(func(context.Context) (map[string]interface{}, error) {
usageMetrics := make(map[string]interface{})
// Enabled / disabled
usageMetrics["stats.encryption.envelope_encryption_enabled.count"] = 0
if s.settings.IsFeatureToggleEnabled(featuremgmt.FlagEnvelopeEncryption) {
usageMetrics["stats.encryption.envelope_encryption_enabled.count"] = 1
}
// Current provider
kind, err := s.currentProviderID.Kind()
if err != nil {
return nil, err
}
usageMetrics[fmt.Sprintf("stats.encryption.current_provider.%s.count", kind)] = 1
// Count by kind
countByKind := make(map[string]int)
for id := range s.providers {
kind, err := id.Kind()
if err != nil {
return nil, err
}
countByKind[kind]++
}
for kind, count := range countByKind {
usageMetrics[fmt.Sprintf(`stats.encryption.providers.%s.count`, kind)] = count
}
return usageMetrics, nil
})
}
type dataKeyCacheItem struct {
expiry time.Time
dataKey []byte
}
var b64 = base64.RawStdEncoding
func (s *SecretsService) Encrypt(ctx context.Context, payload []byte, opt secrets.EncryptionOptions) ([]byte, error) {
return s.EncryptWithDBSession(ctx, payload, opt, nil)
}
func (s *SecretsService) EncryptWithDBSession(ctx context.Context, payload []byte, opt secrets.EncryptionOptions, sess *xorm.Session) ([]byte, error) {
// Use legacy encryption service if envelopeEncryptionFeatureToggle toggle is off
if !s.settings.IsFeatureToggleEnabled(featuremgmt.FlagEnvelopeEncryption) {
return s.enc.Encrypt(ctx, payload, setting.SecretKey)
}
// If encryption featuremgmt.FlagEnvelopeEncryption toggle is on, use envelope encryption
scope := opt()
keyName := s.keyName(scope)
dataKey, err := s.dataKey(ctx, keyName)
if err != nil {
if errors.Is(err, secrets.ErrDataKeyNotFound) {
dataKey, err = s.newDataKey(ctx, keyName, scope, sess)
if err != nil {
return nil, err
}
} else {
return nil, err
}
}
encrypted, err := s.enc.Encrypt(ctx, payload, string(dataKey))
if err != nil {
return nil, err
}
prefix := make([]byte, b64.EncodedLen(len(keyName))+2)
b64.Encode(prefix[1:], []byte(keyName))
prefix[0] = '#'
prefix[len(prefix)-1] = '#'
blob := make([]byte, len(prefix)+len(encrypted))
copy(blob, prefix)
copy(blob[len(prefix):], encrypted)
return blob, nil
}
func (s *SecretsService) keyName(scope string) string {
return fmt.Sprintf("%s/%s@%s", now().Format("2006-01-02"), scope, s.currentProviderID)
}
func (s *SecretsService) Decrypt(ctx context.Context, payload []byte) ([]byte, error) {
// Use legacy encryption service if featuremgmt.FlagEnvelopeEncryption toggle is off
if !s.settings.IsFeatureToggleEnabled(featuremgmt.FlagEnvelopeEncryption) {
return s.enc.Decrypt(ctx, payload, setting.SecretKey)
}
// If encryption featuremgmt.FlagEnvelopeEncryption toggle is on, use envelope encryption
if len(payload) == 0 {
return nil, fmt.Errorf("unable to decrypt empty payload")
}
var dataKey []byte
if payload[0] != '#' {
secretKey := s.settings.KeyValue("security", "secret_key").Value()
dataKey = []byte(secretKey)
} else {
payload = payload[1:]
endOfKey := bytes.Index(payload, []byte{'#'})
if endOfKey == -1 {
return nil, fmt.Errorf("could not find valid key in encrypted payload")
}
b64Key := payload[:endOfKey]
payload = payload[endOfKey+1:]
key := make([]byte, b64.DecodedLen(len(b64Key)))
_, err := b64.Decode(key, b64Key)
if err != nil {
return nil, err
}
dataKey, err = s.dataKey(ctx, string(key))
if err != nil {
s.log.Error("Failed to lookup data key", "name", string(key), "error", err)
return nil, err
}
}
return s.enc.Decrypt(ctx, payload, string(dataKey))
}
func (s *SecretsService) EncryptJsonData(ctx context.Context, kv map[string]string, opt secrets.EncryptionOptions) (map[string][]byte, error) {
return s.EncryptJsonDataWithDBSession(ctx, kv, opt, nil)
}
func (s *SecretsService) EncryptJsonDataWithDBSession(ctx context.Context, kv map[string]string, opt secrets.EncryptionOptions, sess *xorm.Session) (map[string][]byte, error) {
encrypted := make(map[string][]byte)
for key, value := range kv {
encryptedData, err := s.EncryptWithDBSession(ctx, []byte(value), opt, sess)
if err != nil {
return nil, err
}
encrypted[key] = encryptedData
}
return encrypted, nil
}
func (s *SecretsService) DecryptJsonData(ctx context.Context, sjd map[string][]byte) (map[string]string, error) {
decrypted := make(map[string]string)
for key, data := range sjd {
decryptedData, err := s.Decrypt(ctx, data)
if err != nil {
return nil, err
}
decrypted[key] = string(decryptedData)
}
return decrypted, nil
}
func (s *SecretsService) GetDecryptedValue(ctx context.Context, sjd map[string][]byte, key, fallback string) string {
if value, ok := sjd[key]; ok {
decryptedData, err := s.Decrypt(ctx, value)
if err != nil {
return fallback
}
return string(decryptedData)
}
return fallback
}
func newRandomDataKey() ([]byte, error) {
rawDataKey := make([]byte, 16)
_, err := rand.Read(rawDataKey)
if err != nil {
return nil, err
}
return rawDataKey, nil
}
// newDataKey creates a new random DEK, caches it and returns its value
func (s *SecretsService) newDataKey(ctx context.Context, name string, scope string, sess *xorm.Session) ([]byte, error) {
// 1. Create new DEK
dataKey, err := newRandomDataKey()
if err != nil {
return nil, err
}
provider, exists := s.providers[s.currentProviderID]
if !exists {
return nil, fmt.Errorf("could not find encryption provider '%s'", s.currentProviderID)
}
// 2. Encrypt it
encrypted, err := provider.Encrypt(ctx, dataKey)
if err != nil {
return nil, err
}
// 3. Store its encrypted value in db
dek := secrets.DataKey{
Active: true, // TODO: right now we never mark a key as deactivated
Name: name,
Provider: s.currentProviderID,
EncryptedData: encrypted,
Scope: scope,
}
if sess == nil {
err = s.store.CreateDataKey(ctx, dek)
} else {
err = s.store.CreateDataKeyWithDBSession(ctx, dek, sess)
}
if err != nil {
return nil, err
}
// 4. Cache its unencrypted value and return it
s.dataKeyCache[name] = dataKeyCacheItem{
expiry: now().Add(dekTTL),
dataKey: dataKey,
}
return dataKey, nil
}
// dataKey looks up DEK in cache or database, and decrypts it
func (s *SecretsService) dataKey(ctx context.Context, name string) ([]byte, error) {
if item, exists := s.dataKeyCache[name]; exists {
item.expiry = now().Add(dekTTL)
s.dataKeyCache[name] = item
return item.dataKey, nil
}
// 1. get encrypted data key from database
dataKey, err := s.store.GetDataKey(ctx, name)
if err != nil {
return nil, err
}
// 2. decrypt data key
provider, exists := s.providers[dataKey.Provider]
if !exists {
return nil, fmt.Errorf("could not find encryption provider '%s'", dataKey.Provider)
}
decrypted, err := provider.Decrypt(ctx, dataKey.EncryptedData)
if err != nil {
return nil, err
}
// 3. cache data key
s.dataKeyCache[name] = dataKeyCacheItem{
expiry: now().Add(dekTTL),
dataKey: decrypted,
}
return decrypted, nil
}
func (s *SecretsService) GetProviders() map[secrets.ProviderID]secrets.Provider {
return s.providers
}
// These variables are used to test the code
// responsible for periodically cleaning up
// data encryption keys cache.
var (
now = time.Now
dekTTL = 15 * time.Minute
gcInterval = time.Minute
)
func (s *SecretsService) Run(ctx context.Context) error {
gc := time.NewTicker(gcInterval)
for {
select {
case <-gc.C:
s.log.Debug("removing expired data encryption keys from cache...")
s.removeExpiredItems()
s.log.Debug("done removing expired data encryption keys from cache")
case <-ctx.Done():
s.log.Debug("grafana is shutting down; stopping...")
gc.Stop()
return nil
}
}
}
func (s *SecretsService) removeExpiredItems() {
for id, dek := range s.dataKeyCache {
if dek.expiry.Before(now()) {
delete(s.dataKeyCache, id)
}
}
}