Skip to content

Commit

Permalink
Add support for re-encrypting streams with new key (#4296)
Browse files Browse the repository at this point in the history 
This adds a new `prev_key` field to the configuration file to allow
transitioning from one encryption key to another.

Signed-off-by: Neil Twigg <neil@nats.io>
  • Loading branch information
@neilalexander
neilalexander committed Jul 27, 2023
2 parents 4c41c76 + bc78e86 commit b22cdf1
Show file tree
Hide file tree
Showing 8 changed files with 282 additions and 123 deletions.
111 changes: 64 additions & 47 deletions server/filestore.go
View file
Expand Up @@ -165,6 +165,7 @@ type fileStore struct {
cfg FileStreamInfo
fcfg FileStoreConfig
prf keyGen
oldprf keyGen
aek cipher.AEAD
lmb *msgBlock
blks []*msgBlock
Expand Down Expand Up @@ -332,10 +333,10 @@ const (
)

func newFileStore(fcfg FileStoreConfig, cfg StreamConfig) (*fileStore, error) {
return newFileStoreWithCreated(fcfg, cfg, time.Now().UTC(), nil)
return newFileStoreWithCreated(fcfg, cfg, time.Now().UTC(), nil, nil)
}

func newFileStoreWithCreated(fcfg FileStoreConfig, cfg StreamConfig, created time.Time, prf keyGen) (*fileStore, error) {
func newFileStoreWithCreated(fcfg FileStoreConfig, cfg StreamConfig, created time.Time, prf, oldprf keyGen) (*fileStore, error) {
if cfg.Name == _EMPTY_ {
return nil, fmt.Errorf("name required")
}
Expand Down Expand Up @@ -375,12 +376,13 @@ func newFileStoreWithCreated(fcfg FileStoreConfig, cfg StreamConfig, created tim
dios <- struct{}{}

fs := &fileStore{
fcfg: fcfg,
psim: make(map[string]*psi),
bim: make(map[uint32]*msgBlock),
cfg: FileStreamInfo{Created: created, StreamConfig: cfg},
prf: prf,
qch: make(chan struct{}),
fcfg: fcfg,
psim: make(map[string]*psi),
bim: make(map[uint32]*msgBlock),
cfg: FileStreamInfo{Created: created, StreamConfig: cfg},
prf: prf,
oldprf: oldprf,
qch: make(chan struct{}),
}

// Set flush in place to AsyncFlush which by default is false.
Expand Down Expand Up @@ -948,52 +950,67 @@ func (mb *msgBlock) convertCipher() error {
if len(ekey) < minBlkKeySize {
return errBadKeySize
}
// Recover key encryption key.
rb, err := fs.prf([]byte(fmt.Sprintf("%s:%d", fs.cfg.Name, mb.index)))
if err != nil {
return err
type prfWithCipher struct {
keyGen
StoreCipher
}
kek, err := genEncryptionKey(osc, rb)
if err != nil {
return err
var prfs []prfWithCipher
if fs.prf != nil {
prfs = append(prfs, prfWithCipher{fs.prf, sc})
prfs = append(prfs, prfWithCipher{fs.prf, osc})
}
ns := kek.NonceSize()
seed, err := kek.Open(nil, ekey[:ns], ekey[ns:], nil)
if err != nil {
return err
if fs.oldprf != nil {
prfs = append(prfs, prfWithCipher{fs.oldprf, sc})
prfs = append(prfs, prfWithCipher{fs.oldprf, osc})
}
nonce := ekey[:ns]

bek, err := genBlockEncryptionKey(osc, seed, nonce)
if err != nil {
return err
}
for _, prf := range prfs {
// Recover key encryption key.
rb, err := prf.keyGen([]byte(fmt.Sprintf("%s:%d", fs.cfg.Name, mb.index)))
if err != nil {
continue
}
kek, err := genEncryptionKey(prf.StoreCipher, rb)
if err != nil {
continue
}
ns := kek.NonceSize()
seed, err := kek.Open(nil, ekey[:ns], ekey[ns:], nil)
if err != nil {
continue
}
nonce := ekey[:ns]
bek, err := genBlockEncryptionKey(prf.StoreCipher, seed, nonce)
if err != nil {
return err
}

buf, _ := mb.loadBlock(nil)
bek.XORKeyStream(buf, buf)
// Make sure we can parse with old cipher and key file.
if err = mb.indexCacheBuf(buf); err != nil {
return err
}
// Reset the cache since we just read everything in.
mb.cache = nil
buf, _ := mb.loadBlock(nil)
bek.XORKeyStream(buf, buf)
// Make sure we can parse with old cipher and key file.
if err = mb.indexCacheBuf(buf); err != nil {
return err
}
// Reset the cache since we just read everything in.
mb.cache = nil

// Generate new keys based on our
if err := fs.genEncryptionKeysForBlock(mb); err != nil {
// Put the old keyfile back.
keyFile := filepath.Join(mdir, fmt.Sprintf(keyScan, mb.index))
os.WriteFile(keyFile, ekey, defaultFilePerms)
return err
}
mb.bek.XORKeyStream(buf, buf)
if err := os.WriteFile(mb.mfn, buf, defaultFilePerms); err != nil {
return err
// Generate new keys. If we error for some reason then we will put
// the old keyfile back.
if err := fs.genEncryptionKeysForBlock(mb); err != nil {
keyFile := filepath.Join(mdir, fmt.Sprintf(keyScan, mb.index))
os.WriteFile(keyFile, ekey, defaultFilePerms)
return err
}
mb.bek.XORKeyStream(buf, buf)
if err := os.WriteFile(mb.mfn, buf, defaultFilePerms); err != nil {
return err
}
// If we are here we want to delete other meta, e.g. idx, fss.
os.Remove(mb.ifn)
os.Remove(mb.sfn)
return nil
}
// If we are here we want to delete other meta, e.g. idx, fss.
os.Remove(mb.ifn)
os.Remove(mb.sfn)

return nil
return fmt.Errorf("unable to recover keys")
}

// Convert a plaintext block to encrypted.
Expand Down
30 changes: 15 additions & 15 deletions server/filestore_test.go
View file
Expand Up @@ -820,7 +820,7 @@ func TestFileStoreCompact(t *testing.T) {
fcfg,
StreamConfig{Name: "zzz", Storage: FileStorage},
time.Now(),
prf,
prf, nil,
)
if err != nil {
t.Fatalf("Unexpected error: %v", err)
Expand Down Expand Up @@ -865,7 +865,7 @@ func TestFileStoreCompact(t *testing.T) {
fcfg,
StreamConfig{Name: "zzz", Storage: FileStorage},
time.Now(),
prf,
prf, nil,
)
if err != nil {
t.Fatalf("Unexpected error: %v", err)
Expand Down Expand Up @@ -1019,7 +1019,7 @@ func TestFileStoreStreamTruncate(t *testing.T) {
fcfg,
StreamConfig{Name: "zzz", Subjects: []string{"*"}, Storage: FileStorage},
time.Now(),
prf,
prf, nil,
)
if err != nil {
t.Fatalf("Unexpected error: %v", err)
Expand Down Expand Up @@ -1083,7 +1083,7 @@ func TestFileStoreStreamTruncate(t *testing.T) {
fcfg,
StreamConfig{Name: "zzz", Subjects: []string{"foo"}, Storage: FileStorage},
time.Now(),
prf,
prf, nil,
)
if err != nil {
t.Fatalf("Unexpected error: %v", err)
Expand Down Expand Up @@ -3489,7 +3489,7 @@ func TestFileStoreSparseCompaction(t *testing.T) {
prf = nil
}

fs, err = newFileStoreWithCreated(fcfg, cfg, time.Now(), prf)
fs, err = newFileStoreWithCreated(fcfg, cfg, time.Now(), prf, nil)
if err != nil {
t.Fatalf("Unexpected error: %v", err)
}
Expand Down Expand Up @@ -3814,7 +3814,7 @@ func TestFileStoreCompactReclaimHeadSpace(t *testing.T) {
fcfg,
StreamConfig{Name: "TEST", Storage: FileStorage},
time.Now(),
prf,
prf, nil,
)
require_NoError(t, err)
defer fs.Stop()
Expand Down Expand Up @@ -3844,7 +3844,7 @@ func TestFileStoreCompactReclaimHeadSpace(t *testing.T) {
fcfg,
StreamConfig{Name: "TEST", Storage: FileStorage},
time.Now(),
prf,
prf, nil,
)
require_NoError(t, err)
defer fs.Stop()
Expand Down Expand Up @@ -4072,7 +4072,7 @@ func TestFileStoreShortIndexWriteBug(t *testing.T) {
fcfg,
StreamConfig{Name: "TEST", Storage: FileStorage, MaxAge: time.Second},
created,
prf,
prf, nil,
)
require_NoError(t, err)
defer fs.Stop()
Expand Down Expand Up @@ -4108,7 +4108,7 @@ func TestFileStoreShortIndexWriteBug(t *testing.T) {
fcfg,
StreamConfig{Name: "TEST", Storage: FileStorage, MaxAge: time.Second},
created,
prf,
prf, nil,
)
require_NoError(t, err)
defer fs.Stop()
Expand Down Expand Up @@ -4136,7 +4136,7 @@ func TestFileStoreDoubleCompactWithWriteInBetweenEncryptedBug(t *testing.T) {
fcfg,
StreamConfig{Name: "zzz", Storage: FileStorage},
time.Now(),
prf,
prf, nil,
)
require_NoError(t, err)
defer fs.Stop()
Expand Down Expand Up @@ -4188,7 +4188,7 @@ func TestFileStoreEncryptedKeepIndexNeedBekResetBug(t *testing.T) {
fcfg,
StreamConfig{Name: "zzz", Storage: FileStorage, MaxAge: ttl},
time.Now(),
prf,
prf, nil,
)
require_NoError(t, err)
defer fs.Stop()
Expand Down Expand Up @@ -4478,7 +4478,7 @@ func TestFileStoreEncrypted(t *testing.T) {
fcfg,
StreamConfig{Name: "zzz", Storage: FileStorage},
time.Now(),
prf,
prf, nil,
)
require_NoError(t, err)
defer fs.Stop()
Expand All @@ -4505,7 +4505,7 @@ func TestFileStoreEncrypted(t *testing.T) {
fcfg,
StreamConfig{Name: "zzz", Storage: FileStorage},
time.Now(),
prf,
prf, nil,
)
require_NoError(t, err)
defer fs.Stop()
Expand Down Expand Up @@ -5622,7 +5622,7 @@ func TestFileStoreRestoreEncryptedWithNoKeyFuncFails(t *testing.T) {
fs, err := newFileStoreWithCreated(
fcfg, scfg,
time.Now(),
prf,
prf, nil,
)
require_NoError(t, err)

Expand All @@ -5638,7 +5638,7 @@ func TestFileStoreRestoreEncryptedWithNoKeyFuncFails(t *testing.T) {
_, err = newFileStoreWithCreated(
fcfg, scfg,
time.Now(),
nil,
nil, nil,
)
require_Error(t, err, errNoMainKey)
}
Expand Down

0 comments on commit b22cdf1

Please sign in to comment.