/
seal.go
501 lines (410 loc) · 13.9 KB
/
seal.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
package vault
import (
"bytes"
"context"
"encoding/base64"
"encoding/json"
"errors"
"fmt"
"sync/atomic"
"github.com/hashicorp/vault/sdk/helper/jsonutil"
"github.com/hashicorp/vault/sdk/physical"
"github.com/golang/protobuf/proto"
wrapping "github.com/hashicorp/go-kms-wrapping"
"github.com/hashicorp/vault/vault/seal"
"github.com/keybase/go-crypto/openpgp"
"github.com/keybase/go-crypto/openpgp/packet"
)
const (
// barrierSealConfigPath is the path used to store our seal configuration.
// This value is stored in plaintext, since we must be able to read it even
// with the Vault sealed. This is required so that we know how many secret
// parts must be used to reconstruct the master key.
barrierSealConfigPath = "core/seal-config"
// recoverySealConfigPath is the path to the recovery key seal
// configuration. It lives inside the barrier.
// DEPRECATED: Use recoverySealConfigPlaintextPath instead.
recoverySealConfigPath = "core/recovery-seal-config"
// recoverySealConfigPlaintextPath is the path to the recovery key seal
// configuration. This is stored in plaintext so that we can perform
// auto-unseal.
recoverySealConfigPlaintextPath = "core/recovery-config"
// recoveryKeyPath is the path to the recovery key
recoveryKeyPath = "core/recovery-key"
// StoredBarrierKeysPath is the path used for storing HSM-encrypted unseal keys
StoredBarrierKeysPath = "core/hsm/barrier-unseal-keys"
// hsmStoredIVPath is the path to the initialization vector for stored keys
hsmStoredIVPath = "core/hsm/iv"
)
const (
RecoveryTypeUnsupported = "unsupported"
RecoveryTypeShamir = "shamir"
)
type Seal interface {
SetCore(*Core)
Init(context.Context) error
Finalize(context.Context) error
StoredKeysSupported() seal.StoredKeysSupport
SealWrapable() bool
SetStoredKeys(context.Context, [][]byte) error
GetStoredKeys(context.Context) ([][]byte, error)
BarrierType() string
BarrierConfig(context.Context) (*SealConfig, error)
SetBarrierConfig(context.Context, *SealConfig) error
SetCachedBarrierConfig(*SealConfig)
RecoveryKeySupported() bool
RecoveryType() string
RecoveryConfig(context.Context) (*SealConfig, error)
RecoveryKey(context.Context) ([]byte, error)
SetRecoveryConfig(context.Context, *SealConfig) error
SetCachedRecoveryConfig(*SealConfig)
SetRecoveryKey(context.Context, []byte) error
VerifyRecoveryKey(context.Context, []byte) error
GetAccess() *seal.Access
}
type defaultSeal struct {
access *seal.Access
config atomic.Value
core *Core
}
func NewDefaultSeal(lowLevel *seal.Access) Seal {
ret := &defaultSeal{
access: lowLevel,
}
ret.config.Store((*SealConfig)(nil))
return ret
}
func (d *defaultSeal) SealWrapable() bool {
return false
}
func (d *defaultSeal) checkCore() error {
if d.core == nil {
return fmt.Errorf("seal does not have a core set")
}
return nil
}
func (d *defaultSeal) GetAccess() *seal.Access {
return d.access
}
func (d *defaultSeal) SetAccess(access *seal.Access) {
d.access = access
}
func (d *defaultSeal) SetCore(core *Core) {
d.core = core
}
func (d *defaultSeal) Init(ctx context.Context) error {
return nil
}
func (d *defaultSeal) Finalize(ctx context.Context) error {
return nil
}
func (d *defaultSeal) BarrierType() string {
return wrapping.Shamir
}
func (d *defaultSeal) StoredKeysSupported() seal.StoredKeysSupport {
switch {
case d.LegacySeal():
return seal.StoredKeysNotSupported
default:
return seal.StoredKeysSupportedShamirMaster
}
}
func (d *defaultSeal) RecoveryKeySupported() bool {
return false
}
func (d *defaultSeal) SetStoredKeys(ctx context.Context, keys [][]byte) error {
if d.LegacySeal() {
return fmt.Errorf("stored keys are not supported")
}
return writeStoredKeys(ctx, d.core.physical, d.access, keys)
}
func (d *defaultSeal) LegacySeal() bool {
cfg := d.config.Load().(*SealConfig)
if cfg == nil {
return false
}
return cfg.StoredShares == 0
}
func (d *defaultSeal) GetStoredKeys(ctx context.Context) ([][]byte, error) {
if d.LegacySeal() {
return nil, fmt.Errorf("stored keys are not supported")
}
keys, err := readStoredKeys(ctx, d.core.physical, d.access)
return keys, err
}
func (d *defaultSeal) BarrierConfig(ctx context.Context) (*SealConfig, error) {
cfg := d.config.Load().(*SealConfig)
if cfg != nil {
return cfg.Clone(), nil
}
if err := d.checkCore(); err != nil {
return nil, err
}
// Fetch the core configuration
pe, err := d.core.physical.Get(ctx, barrierSealConfigPath)
if err != nil {
d.core.logger.Error("failed to read seal configuration", "error", err)
return nil, fmt.Errorf("failed to check seal configuration: %w", err)
}
// If the seal configuration is missing, we are not initialized
if pe == nil {
d.core.logger.Info("seal configuration missing, not initialized")
return nil, nil
}
var conf SealConfig
// Decode the barrier entry
if err := jsonutil.DecodeJSON(pe.Value, &conf); err != nil {
d.core.logger.Error("failed to decode seal configuration", "error", err)
return nil, fmt.Errorf("failed to decode seal configuration: %w", err)
}
switch conf.Type {
// This case should not be valid for other types as only this is the default
case "":
conf.Type = d.BarrierType()
case d.BarrierType():
default:
d.core.logger.Error("barrier seal type does not match expected type", "barrier_seal_type", conf.Type, "loaded_seal_type", d.BarrierType())
return nil, fmt.Errorf("barrier seal type of %q does not match expected type of %q", conf.Type, d.BarrierType())
}
// Check for a valid seal configuration
if err := conf.Validate(); err != nil {
d.core.logger.Error("invalid seal configuration", "error", err)
return nil, fmt.Errorf("seal validation failed: %w", err)
}
d.SetCachedBarrierConfig(&conf)
return conf.Clone(), nil
}
func (d *defaultSeal) SetBarrierConfig(ctx context.Context, config *SealConfig) error {
if err := d.checkCore(); err != nil {
return err
}
// Provide a way to wipe out the cached value (also prevents actually
// saving a nil config)
if config == nil {
d.config.Store((*SealConfig)(nil))
return nil
}
config.Type = d.BarrierType()
// If we are doing a raft unseal we do not want to persist the barrier config
// because storage isn't setup yet.
if d.core.isRaftUnseal() {
d.config.Store(config.Clone())
return nil
}
// Encode the seal configuration
buf, err := json.Marshal(config)
if err != nil {
return fmt.Errorf("failed to encode seal configuration: %w", err)
}
// Store the seal configuration
pe := &physical.Entry{
Key: barrierSealConfigPath,
Value: buf,
}
if err := d.core.physical.Put(ctx, pe); err != nil {
d.core.logger.Error("failed to write seal configuration", "error", err)
return fmt.Errorf("failed to write seal configuration: %w", err)
}
d.SetCachedBarrierConfig(config.Clone())
return nil
}
func (d *defaultSeal) SetCachedBarrierConfig(config *SealConfig) {
d.config.Store(config)
}
func (d *defaultSeal) RecoveryType() string {
return RecoveryTypeUnsupported
}
func (d *defaultSeal) RecoveryConfig(ctx context.Context) (*SealConfig, error) {
return nil, fmt.Errorf("recovery not supported")
}
func (d *defaultSeal) RecoveryKey(ctx context.Context) ([]byte, error) {
return nil, fmt.Errorf("recovery not supported")
}
func (d *defaultSeal) SetRecoveryConfig(ctx context.Context, config *SealConfig) error {
return fmt.Errorf("recovery not supported")
}
func (d *defaultSeal) SetCachedRecoveryConfig(config *SealConfig) {
}
func (d *defaultSeal) VerifyRecoveryKey(ctx context.Context, key []byte) error {
return fmt.Errorf("recovery not supported")
}
func (d *defaultSeal) SetRecoveryKey(ctx context.Context, key []byte) error {
return fmt.Errorf("recovery not supported")
}
// SealConfig is used to describe the seal configuration
type SealConfig struct {
// The type, for sanity checking
Type string `json:"type" mapstructure:"type"`
// SecretShares is the number of shares the secret is split into. This is
// the N value of Shamir.
SecretShares int `json:"secret_shares" mapstructure:"secret_shares"`
// SecretThreshold is the number of parts required to open the vault. This
// is the T value of Shamir.
SecretThreshold int `json:"secret_threshold" mapstructure:"secret_threshold"`
// PGPKeys is the array of public PGP keys used, if requested, to encrypt
// the output unseal tokens. If provided, it sets the value of
// SecretShares. Ordering is important.
PGPKeys []string `json:"pgp_keys" mapstructure:"pgp_keys"`
// Nonce is a nonce generated by Vault used to ensure that when unseal keys
// are submitted for a rekey operation, the rekey operation itself is the
// one intended. This prevents hijacking of the rekey operation, since it
// is unauthenticated.
Nonce string `json:"nonce" mapstructure:"nonce"`
// Backup indicates whether or not a backup of PGP-encrypted unseal keys
// should be stored at coreUnsealKeysBackupPath after successful rekeying.
Backup bool `json:"backup" mapstructure:"backup"`
// How many keys to store, for seals that support storage. Always 0 or 1.
StoredShares int `json:"stored_shares" mapstructure:"stored_shares"`
// Stores the progress of the rekey operation (key shares)
RekeyProgress [][]byte `json:"-"`
// VerificationRequired indicates that after a rekey validation must be
// performed (via providing shares from the new key) before the new key is
// actually installed. This is omitted from JSON as we don't persist the
// new key, it lives only in memory.
VerificationRequired bool `json:"-"`
// VerificationKey is the new key that we will roll to after successful
// validation
VerificationKey []byte `json:"-"`
// VerificationNonce stores the current operation nonce for verification
VerificationNonce string `json:"-"`
// Stores the progress of the verification operation (key shares)
VerificationProgress [][]byte `json:"-"`
}
// Validate is used to sanity check the seal configuration
func (s *SealConfig) Validate() error {
if s.SecretShares < 1 {
return fmt.Errorf("shares must be at least one")
}
if s.SecretThreshold < 1 {
return fmt.Errorf("threshold must be at least one")
}
if s.SecretShares > 1 && s.SecretThreshold == 1 {
return fmt.Errorf("threshold must be greater than one for multiple shares")
}
if s.SecretShares > 255 {
return fmt.Errorf("shares must be less than 256")
}
if s.SecretThreshold > 255 {
return fmt.Errorf("threshold must be less than 256")
}
if s.SecretThreshold > s.SecretShares {
return fmt.Errorf("threshold cannot be larger than shares")
}
if s.StoredShares > 1 {
return fmt.Errorf("stored keys cannot be larger than 1")
}
if len(s.PGPKeys) > 0 && len(s.PGPKeys) != s.SecretShares {
return fmt.Errorf("count mismatch between number of provided PGP keys and number of shares")
}
if len(s.PGPKeys) > 0 {
for _, keystring := range s.PGPKeys {
data, err := base64.StdEncoding.DecodeString(keystring)
if err != nil {
return fmt.Errorf("error decoding given PGP key: %w", err)
}
_, err = openpgp.ReadEntity(packet.NewReader(bytes.NewBuffer(data)))
if err != nil {
return fmt.Errorf("error parsing given PGP key: %w", err)
}
}
}
return nil
}
func (s *SealConfig) Clone() *SealConfig {
ret := &SealConfig{
Type: s.Type,
SecretShares: s.SecretShares,
SecretThreshold: s.SecretThreshold,
Nonce: s.Nonce,
Backup: s.Backup,
StoredShares: s.StoredShares,
VerificationRequired: s.VerificationRequired,
VerificationNonce: s.VerificationNonce,
}
if len(s.PGPKeys) > 0 {
ret.PGPKeys = make([]string, len(s.PGPKeys))
copy(ret.PGPKeys, s.PGPKeys)
}
if len(s.VerificationKey) > 0 {
ret.VerificationKey = make([]byte, len(s.VerificationKey))
copy(ret.VerificationKey, s.VerificationKey)
}
return ret
}
type ErrEncrypt struct {
Err error
}
var _ error = &ErrEncrypt{}
func (e *ErrEncrypt) Error() string {
return e.Err.Error()
}
func (e *ErrEncrypt) Is(target error) bool {
_, ok := target.(*ErrEncrypt)
return ok || errors.Is(e.Err, target)
}
type ErrDecrypt struct {
Err error
}
var _ error = &ErrDecrypt{}
func (e *ErrDecrypt) Error() string {
return e.Err.Error()
}
func (e *ErrDecrypt) Is(target error) bool {
_, ok := target.(*ErrDecrypt)
return ok || errors.Is(e.Err, target)
}
func writeStoredKeys(ctx context.Context, storage physical.Backend, encryptor *seal.Access, keys [][]byte) error {
if keys == nil {
return fmt.Errorf("keys were nil")
}
if len(keys) == 0 {
return fmt.Errorf("no keys provided")
}
buf, err := json.Marshal(keys)
if err != nil {
return fmt.Errorf("failed to encode keys for storage: %w", err)
}
// Encrypt and marshal the keys
blobInfo, err := encryptor.Encrypt(ctx, buf, nil)
if err != nil {
return &ErrEncrypt{Err: fmt.Errorf("failed to encrypt keys for storage: %w", err)}
}
value, err := proto.Marshal(blobInfo)
if err != nil {
return fmt.Errorf("failed to marshal value for storage: %w", err)
}
// Store the seal configuration.
pe := &physical.Entry{
Key: StoredBarrierKeysPath,
Value: value,
}
if err := storage.Put(ctx, pe); err != nil {
return fmt.Errorf("failed to write keys to storage: %w", err)
}
return nil
}
func readStoredKeys(ctx context.Context, storage physical.Backend, encryptor *seal.Access) ([][]byte, error) {
pe, err := storage.Get(ctx, StoredBarrierKeysPath)
if err != nil {
return nil, fmt.Errorf("failed to fetch stored keys: %w", err)
}
// This is not strictly an error; we may not have any stored keys, for
// instance, if we're not initialized
if pe == nil {
return nil, nil
}
blobInfo := &wrapping.EncryptedBlobInfo{}
if err := proto.Unmarshal(pe.Value, blobInfo); err != nil {
return nil, fmt.Errorf("failed to proto decode stored keys: %w", err)
}
pt, err := encryptor.Decrypt(ctx, blobInfo, nil)
if err != nil {
return nil, &ErrDecrypt{Err: fmt.Errorf("failed to decrypt keys from storage: %w", err)}
}
// Decode the barrier entry
var keys [][]byte
if err := json.Unmarshal(pt, &keys); err != nil {
return nil, fmt.Errorf("failed to decode stored keys: %v", err)
}
return keys, nil
}