revocation.go 11.1 KB
Newer Older
1
2
3
4
5
6
7
8
9
package irma

import (
	"fmt"
	"path/filepath"
	"time"

	"github.com/go-errors/errors"
	"github.com/hashicorp/go-multierror"
10
	"github.com/privacybydesign/gabi/big"
11
	"github.com/privacybydesign/gabi/revocation"
12
	"github.com/privacybydesign/gabi/signed"
13
14
	"github.com/timshannon/bolthold"
	bolt "go.etcd.io/bbolt"
15
16
)

17
18
type (
	// DB is a bolthold database storing revocation state for a particular accumulator
19
	// (Record instances, and IssuanceRecord instances if used by an issuer).
20
21
22
	DB struct {
		Current  revocation.Accumulator
		Updated  time.Time
23
		onChange []func(*revocation.Record)
24
		bolt     *bolthold.Store
25
		keystore revocation.Keystore
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
	}

	RevocationStorage struct {
		dbs  map[CredentialTypeIdentifier]*DB
		conf *Configuration
	}

	TimeRecord struct {
		Index      uint64
		Start, End int64
	}

	// IssuanceRecord contains information generated during issuance, needed for later revocation.
	IssuanceRecord struct {
		Key        string
		Attr       *big.Int
		Issued     int64
		ValidUntil int64
		RevokedAt  int64 // 0 if not currently revoked
	}

	currentRecord struct {
		Index uint64
	}
)

const boltCurrentIndexKey = "currentIndex"

func (rdb *DB) EnableRevocation(sk *revocation.PrivateKey) error {
	msg, acc, err := revocation.NewAccumulator(sk)
	if err != nil {
		return err
	}
	if err = rdb.Add(msg, sk.Counter); err != nil {
		return err
	}
62
	rdb.Current = *acc
63
	rdb.Updated = time.Now()
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
	return nil
}

// Revoke revokes the credential specified specified by key if found within the current database,
// by updating its revocation time to now, adding its revocation attribute to the current accumulator,
// and updating the revocation database on disk.
func (rdb *DB) Revoke(sk *revocation.PrivateKey, key []byte) error {
	return rdb.bolt.Bolt().Update(func(tx *bolt.Tx) error {
		var err error
		cr := IssuanceRecord{}
		if err = rdb.bolt.TxGet(tx, key, &cr); err != nil {
			return err
		}
		cr.RevokedAt = time.Now().UnixNano()
		if err = rdb.bolt.TxUpdate(tx, key, &cr); err != nil {
			return err
		}
		return rdb.revokeAttr(sk, cr.Attr, tx)
	})
}

// Get returns all records that a client requires to update its revocation state if it is currently
// at the specified index, that is, all records whose end index is greater than or equal to
// the specified index.
88
89
func (rdb *DB) RevocationRecords(index int) ([]*revocation.Record, error) {
	var records []*revocation.Record
90
91
92
93
94
95
	if err := rdb.bolt.Find(&records, bolthold.Where(bolthold.Key).Ge(uint64(index))); err != nil {
		return nil, err
	}
	return records, nil
}

96
func (rdb *DB) LatestRecords(count int) ([]*revocation.Record, error) {
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
	c := int(rdb.Current.Index) - count + 1
	if c < 0 {
		c = 0
	}
	return rdb.RevocationRecords(c)
}

func (rdb *DB) IssuanceRecordExists(key []byte) (bool, error) {
	_, err := rdb.IssuanceRecord(key)
	switch err {
	case nil:
		return true, nil
	case bolthold.ErrNotFound:
		return false, nil
	default:
		return false, err
	}
}

func (rdb *DB) AddIssuanceRecord(r *IssuanceRecord) error {
	return rdb.bolt.Insert([]byte(r.Key), r)
}

func (rdb *DB) IssuanceRecord(key []byte) (*IssuanceRecord, error) {
	r := &IssuanceRecord{}
	if err := rdb.bolt.Get(key, r); err != nil {
		return nil, err
	}
	return r, nil
}

128
func (rdb *DB) AddRecords(records []*revocation.Record) error {
129
130
131
132
133
134
135
136
137
138
	var err error
	for _, r := range records {
		if err = rdb.Add(r.Message, r.PublicKeyIndex); err != nil {
			return err
		}
	}
	rdb.Updated = time.Now() // TODO update this in add()?
	return nil
}

139
// TODO this should use revocation.Record.UnmarshalVerify
140
141
142
143
func (rdb *DB) Add(updateMsg signed.Message, counter uint) error {
	var err error
	var update revocation.AccumulatorUpdate

144
	pk, err := rdb.keystore(counter)
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
	if err != nil {
		return err
	}

	if err = signed.UnmarshalVerify(pk.ECDSA, updateMsg, &update); err != nil {
		return err
	}

	return rdb.bolt.Bolt().Update(func(tx *bolt.Tx) error {
		return rdb.add(update, updateMsg, counter, tx)
	})
}

func (rdb *DB) add(update revocation.AccumulatorUpdate, updateMsg signed.Message, pkCounter uint, tx *bolt.Tx) error {
	var err error
160
	record := &revocation.Record{
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
		StartIndex:     update.StartIndex,
		EndIndex:       update.Accumulator.Index,
		PublicKeyIndex: pkCounter,
		Message:        updateMsg,
	}
	if err = rdb.bolt.TxInsert(tx, update.Accumulator.Index, record); err != nil {
		return err
	}

	if update.Accumulator.Index != 0 {
		var tr TimeRecord
		if err = rdb.bolt.TxGet(tx, update.Accumulator.Index-1, &tr); err == nil {
			tr.End = time.Now().UnixNano()
			if err = rdb.bolt.TxUpdate(tx, update.Accumulator.Index-1, &tr); err != nil {
				return err
			}
		}
	}
	if err = rdb.bolt.TxInsert(tx, update.Accumulator.Index, &TimeRecord{
		Index: update.Accumulator.Index,
		Start: time.Now().UnixNano(),
	}); err != nil {
		return err
	}

	if err = rdb.bolt.TxUpsert(tx, boltCurrentIndexKey, &currentRecord{update.Accumulator.Index}); err != nil {
		return err
	}

	for _, f := range rdb.onChange {
		f(record)
	}

	rdb.Current = update.Accumulator
	return nil
}

func (rdb *DB) Enabled() bool {
	var currentIndex currentRecord
	err := rdb.bolt.Get(boltCurrentIndexKey, &currentIndex)
	return err == nil
}

func (rdb *DB) loadCurrent() error {
	var currentIndex currentRecord
	if err := rdb.bolt.Get(boltCurrentIndexKey, &currentIndex); err == bolthold.ErrNotFound {
		return errors.New("revocation database not initialized")
	} else if err != nil {
		return err
	}

212
	var record revocation.Record
213
214
215
	if err := rdb.bolt.Get(currentIndex.Index, &record); err != nil {
		return err
	}
216
	pk, err := rdb.keystore(record.PublicKeyIndex)
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
	if err != nil {
		return err
	}
	var u revocation.AccumulatorUpdate
	if err = signed.UnmarshalVerify(pk.ECDSA, record.Message, &u); err != nil {
		return err
	}
	rdb.Current = u.Accumulator
	return nil
}

func (rdb *DB) RevokeAttr(sk *revocation.PrivateKey, e *big.Int) error {
	return rdb.bolt.Bolt().Update(func(tx *bolt.Tx) error {
		return rdb.revokeAttr(sk, e, tx)
	})
}

func (rdb *DB) revokeAttr(sk *revocation.PrivateKey, e *big.Int, tx *bolt.Tx) error {
	// don't update rdb.Current until after all possible errors are handled
	newAcc, err := rdb.Current.Remove(sk, e)
	if err != nil {
		return err
	}
	update := revocation.AccumulatorUpdate{
		Accumulator: *newAcc,
		StartIndex:  newAcc.Index,
		Revoked:     []*big.Int{e},
		Time:        time.Now().UnixNano(),
	}
	updateMsg, err := signed.MarshalSign(sk.ECDSA, update)
	if err != nil {
		return err
	}
	if err = rdb.add(update, updateMsg, sk.Counter, tx); err != nil {
		return err
	}
	rdb.Current = *newAcc
	return nil
}

func (rdb *DB) Close() error {
	rdb.onChange = nil
	if rdb.bolt != nil {
		return rdb.bolt.Close()
	}
	return nil
}

265
func (rdb *DB) OnChange(handler func(*revocation.Record)) {
266
267
268
	rdb.onChange = append(rdb.onChange, handler)
}

269
func (rs *RevocationStorage) loadDB(credid CredentialTypeIdentifier) (*DB, error) {
270
	path := filepath.Join(rs.conf.RevocationPath, credid.String())
271
	keystore := rs.Keystore(credid.IssuerIdentifier())
272
273
274
275
276
277
278
279

	b, err := bolthold.Open(path, 0600, &bolthold.Options{Options: &bolt.Options{Timeout: 1 * time.Second}})
	if err != nil {
		return nil, err
	}
	db := &DB{
		bolt:     b,
		keystore: keystore,
280
		Updated:  time.Unix(0, 0),
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
	}
	if db.Enabled() {
		if err = db.loadCurrent(); err != nil {
			_ = db.Close()
			return nil, err
		}
	}
	return db, nil
}

func (rs *RevocationStorage) PublicKey(issid IssuerIdentifier, counter uint) (*revocation.PublicKey, error) {
	pk, err := rs.conf.PublicKey(issid, int(counter))
	if err != nil {
		return nil, err
	}
	if pk == nil {
		return nil, errors.Errorf("unknown public key: %s-%d", issid, counter)
	}
	revpk, err := pk.RevocationKey()
	if err != nil {
		return nil, err
	}
	return revpk, nil
}

306
307
func (rs *RevocationStorage) GetUpdates(credid CredentialTypeIdentifier, index uint64) ([]*revocation.Record, error) {
	var records []*revocation.Record
308
	err := NewHTTPTransport(rs.conf.CredentialTypes[credid].RevocationServer).
309
310
311
312
313
314
315
		Get(fmt.Sprintf("-/revocation/records/%s/%d", credid, index), &records)
	if err != nil {
		return nil, err
	}
	return records, nil
}

316
func (rs *RevocationStorage) UpdateAll() error {
317
	var err error
318
	for credid := range rs.dbs {
319
		if err = rs.UpdateDB(credid); err != nil {
320
321
322
323
324
325
			return err
		}
	}
	return nil
}

326
func (rs *RevocationStorage) SetRecords(b *BaseRequest) error {
327
328
329
	if len(b.Revocation) == 0 {
		return nil
	}
330
	b.RevocationUpdates = make(map[CredentialTypeIdentifier][]*revocation.Record, len(b.Revocation))
331
	for _, credid := range b.Revocation {
332
		db, err := rs.DB(credid)
333
334
335
		if err != nil {
			return err
		}
336
		if err = rs.updateDelayed(credid, db); err != nil {
337
338
339
340
341
342
343
344
345
346
			return err
		}
		b.RevocationUpdates[credid], err = db.LatestRecords(revocationUpdateCount)
		if err != nil {
			return err
		}
	}
	return nil
}

347
348
func (rs *RevocationStorage) UpdateDB(credid CredentialTypeIdentifier) error {
	db, err := rs.DB(credid)
349
350
351
352
353
354
355
	if err != nil {
		return err
	}
	var index uint64
	if db.Enabled() {
		index = db.Current.Index + 1
	}
356
	records, err := rs.GetUpdates(credid, index)
357
358
359
360
361
362
	if err != nil {
		return err
	}
	return db.AddRecords(records)
}

363
func (rs *RevocationStorage) DB(credid CredentialTypeIdentifier) (*DB, error) {
364
	if _, known := rs.conf.CredentialTypes[credid]; !known {
365
366
		return nil, errors.New("unknown credential type")
	}
367
368
	if rs.dbs == nil {
		rs.dbs = make(map[CredentialTypeIdentifier]*DB)
369
	}
370
	if rs.dbs[credid] == nil {
371
		var err error
372
		db, err := rs.loadDB(credid)
373
374
375
		if err != nil {
			return nil, err
		}
376
		rs.dbs[credid] = db
377
	}
378
	return rs.dbs[credid], nil
379
380
}

381
func (rs *RevocationStorage) updateDelayed(credid CredentialTypeIdentifier, db *DB) error {
382
	if db.Updated.Before(time.Now().Add(-5 * time.Minute)) {
383
		if err := rs.UpdateDB(credid); err != nil {
384
385
386
387
388
389
			return err
		}
	}
	return nil
}

390
func (rs *RevocationStorage) SendIssuanceRecord(cred CredentialTypeIdentifier, rec *IssuanceRecord) error {
391
	credtype := rs.conf.CredentialTypes[cred]
392
393
394
395
396
397
	if credtype == nil {
		return errors.New("unknown credential type")
	}
	if credtype.RevocationServer == "" {
		return errors.New("credential type has no revocation server")
	}
398
	sk, err := rs.conf.PrivateKey(cred.IssuerIdentifier())
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
	if err != nil {
		return err
	}
	if sk == nil {
		return errors.New("private key not found")
	}
	revsk, err := sk.RevocationKey()
	if err != nil {
		return err
	}

	message, err := signed.MarshalSign(revsk.ECDSA, rec)
	if err != nil {
		return err
	}
	return NewHTTPTransport(credtype.RevocationServer).Post(
		fmt.Sprintf("-/revocation/issuancerecord/%s/%d", cred, sk.Counter), nil, []byte(message),
	)
}

419
420
func (rs *RevocationStorage) Revoke(credid CredentialTypeIdentifier, key string) error {
	sk, err := rs.conf.PrivateKey(credid.IssuerIdentifier())
421
422
423
424
425
426
427
428
429
430
431
	if err != nil {
		return err
	}
	if sk == nil {
		return errors.New("private key not found")
	}
	rsk, err := sk.RevocationKey()
	if err != nil {
		return err
	}

432
	db, err := rs.DB(credid)
433
434
435
436
437
438
	if err != nil {
		return err
	}
	return db.Revoke(rsk, []byte(key))
}

439
func (rs *RevocationStorage) Close() error {
440
441
	merr := &multierror.Error{}
	var err error
442
	for _, db := range rs.dbs {
443
444
445
446
		if err = db.Close(); err != nil {
			merr = multierror.Append(merr, err)
		}
	}
447
	rs.dbs = nil
448
449
	return merr.ErrorOrNil()
}
450

451
func (rs *RevocationStorage) Keystore(issuerid IssuerIdentifier) revocation.Keystore {
452
	return func(counter uint) (*revocation.PublicKey, error) {
453
		return rs.PublicKey(issuerid, counter)
454
455
	}
}