-
Notifications
You must be signed in to change notification settings - Fork 1.2k
/
paperkey_gen.go
371 lines (313 loc) · 9.25 KB
/
paperkey_gen.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
// Copyright 2015 Keybase, Inc. All rights reserved. Use of
// this source code is governed by the included BSD license.
package engine
import (
"bytes"
"errors"
"fmt"
"github.com/keybase/go-crypto/ed25519"
"golang.org/x/crypto/nacl/box"
"golang.org/x/crypto/scrypt"
"github.com/keybase/client/go/kbcrypto"
"github.com/keybase/client/go/libkb"
"github.com/keybase/client/go/protocol/keybase1"
)
type PaperKeyGenArg struct {
Passphrase libkb.PaperKeyPhrase
SkipPush bool
// One of Me or UID is required
// Me is required if not SkipPush
Me *libkb.User
UID keybase1.UID
SigningKey libkb.GenericKey // optional
EncryptionKey libkb.NaclDHKeyPair // optional
PerUserKeyring *libkb.PerUserKeyring // optional
IsEldest bool
}
// PaperKeyGen is an engine.
type PaperKeyGen struct {
arg *PaperKeyGenArg
// keys of the generated paper key
sigKey libkb.GenericKey
encKey libkb.NaclDHKeyPair
deviceID keybase1.DeviceID
libkb.Contextified
}
// NewPaperKeyGen creates a PaperKeyGen engine.
func NewPaperKeyGen(g *libkb.GlobalContext, arg *PaperKeyGenArg) *PaperKeyGen {
return &PaperKeyGen{
arg: arg,
Contextified: libkb.NewContextified(g),
}
}
// Name is the unique engine name.
func (e *PaperKeyGen) Name() string {
return "PaperKeyGen"
}
// GetPrereqs returns the engine prereqs.
func (e *PaperKeyGen) Prereqs() Prereqs {
// only need a device if pushing keys
return Prereqs{
Device: !e.arg.SkipPush && !e.arg.IsEldest,
}
}
// RequiredUIs returns the required UIs.
func (e *PaperKeyGen) RequiredUIs() []libkb.UIKind {
return []libkb.UIKind{}
}
// SubConsumers returns the other UI consumers for this engine.
func (e *PaperKeyGen) SubConsumers() []libkb.UIConsumer {
return nil
}
func (e *PaperKeyGen) SigKey() libkb.GenericKey {
return e.sigKey
}
func (e *PaperKeyGen) EncKey() libkb.NaclDHKeyPair {
return e.encKey
}
func (e *PaperKeyGen) DeviceID() keybase1.DeviceID {
return e.deviceID
}
func (e *PaperKeyGen) DeviceWithKeys() *libkb.DeviceWithKeys {
return libkb.NewDeviceWithKeysOnly(e.sigKey, e.encKey, libkb.KeychainModeNone)
}
// Run starts the engine.
func (e *PaperKeyGen) Run(m libkb.MetaContext) error {
if !e.arg.SkipPush {
err := e.syncPUK(m)
if err != nil {
return err
}
}
// make the passphrase stream
key, err := scrypt.Key(e.arg.Passphrase.Bytes(), nil,
libkb.PaperKeyScryptCost, libkb.PaperKeyScryptR, libkb.PaperKeyScryptP, libkb.PaperKeyScryptKeylen)
if err != nil {
return err
}
ppStream := libkb.NewPassphraseStream(key)
// make keys for the paper device
if err := e.makeSigKey(ppStream.EdDSASeed()); err != nil {
return err
}
if err := e.makeEncKey(ppStream.DHSeed()); err != nil {
return err
}
// push everything to the server
if err := e.push(m); err != nil {
return err
}
// no need to notify if key wasn't pushed to server
// (e.g. in the case of using this engine to verify a key)
if e.arg.SkipPush {
return nil
}
e.G().KeyfamilyChanged(m.Ctx(), e.getUID())
return nil
}
func (e *PaperKeyGen) getUID() keybase1.UID {
if !e.arg.UID.IsNil() {
return e.arg.UID
}
if e.arg.Me != nil {
return e.arg.Me.GetUID()
}
return keybase1.UID("")
}
func (e *PaperKeyGen) syncPUK(m libkb.MetaContext) error {
// Sync the per-user-key keyring before updating other things.
pukring, err := e.getPerUserKeyring(m)
if err != nil {
return err
}
var upak *keybase1.UserPlusAllKeys
if e.arg.Me != nil {
tmp := e.arg.Me.ExportToUserPlusAllKeys()
upak = &tmp
}
err = pukring.SyncWithExtras(m, upak)
if err != nil {
return err
}
return nil
}
func (e *PaperKeyGen) makeSigKey(seed []byte) error {
pub, priv, err := ed25519.GenerateKey(bytes.NewBuffer(seed))
if err != nil {
return err
}
var key libkb.NaclSigningKeyPair
copy(key.Public[:], pub[:])
key.Private = &kbcrypto.NaclSigningKeyPrivate{}
copy(key.Private[:], priv[:])
e.sigKey = key
return nil
}
func (e *PaperKeyGen) makeEncKey(seed []byte) error {
pub, priv, err := box.GenerateKey(bytes.NewBuffer(seed))
if err != nil {
return err
}
var key libkb.NaclDHKeyPair
copy(key.Public[:], (*pub)[:])
key.Private = &libkb.NaclDHKeyPrivate{}
copy(key.Private[:], (*priv)[:])
e.encKey = key
return nil
}
func (e *PaperKeyGen) getClientHalfFromSecretStore(m libkb.MetaContext) (clientHalf libkb.LKSecClientHalf, ppgen libkb.PassphraseGeneration, err error) {
defer m.Trace("PaperKeyGen#getClientHalfFromSecretStore", &err)
secretStore := libkb.NewSecretStore(m, e.arg.Me.GetNormalizedName())
if secretStore == nil {
return clientHalf, ppgen, errors.New("No secret store available")
}
secret, err := secretStore.RetrieveSecret(m)
if err != nil {
return clientHalf, ppgen, err
}
devid := e.G().Env.GetDeviceID()
if devid.IsNil() {
return clientHalf, ppgen, fmt.Errorf("no device id set")
}
var ss *libkb.SecretSyncer
ss, err = m.ActiveDevice().SyncSecrets(m)
if err != nil {
return clientHalf, ppgen, err
}
var dev libkb.DeviceKey
dev, err = ss.FindDevice(devid)
if err != nil {
return clientHalf, ppgen, err
}
serverHalf, err := libkb.NewLKSecServerHalfFromHex(dev.LksServerHalf)
if err != nil {
return clientHalf, ppgen, err
}
clientHalf = serverHalf.ComputeClientHalf(secret)
return clientHalf, dev.PPGen, nil
}
func (e *PaperKeyGen) push(m libkb.MetaContext) (err error) {
defer m.Trace("PaperKeyGen#push", &err)()
if e.arg.SkipPush {
return nil
}
if e.arg.Me == nil {
return errors.New("no Me object but we wanted to push public keys")
}
// Create a new paper key device. Need the passphrase prefix
// for the paper device name. This is the first two words in
// the passphrase. There is sufficient entropy to cover this...
backupDev, err := libkb.NewPaperDevice(e.arg.Passphrase.Prefix())
if err != nil {
return err
}
e.deviceID = backupDev.ID
// create lks halves for this device. Note that they aren't used for
// local, encrypted storage of the paper keys, but just for recovery
// purposes.
m.Dump()
// Clear the passphrase stream if it's outdated, just in case some
// other device changed the passphrase.
if err := m.G().ActiveDevice.ClearPassphraseStreamCacheIfOutdated(m); err != nil {
return err
}
var ppgen libkb.PassphraseGeneration
var clientHalf libkb.LKSecClientHalf
if stream := m.PassphraseStream(); stream != nil {
m.Debug("Got cached passphrase stream")
clientHalf = stream.LksClientHalf()
ppgen = stream.Generation()
} else {
m.Debug("Got nil passphrase stream; going to secret store")
// stream was nil, so we must have loaded lks from the secret
// store.
clientHalf, ppgen, err = e.getClientHalfFromSecretStore(m)
switch err.(type) {
case nil:
case libkb.SecretStoreError:
// as a last resort try to prompt the user for their passphrase if
// the SecretUI is present
if m.UIs().HasUI(libkb.SecretUIKind) {
if pps, _, perr := libkb.GetPassphraseStreamViaPrompt(m); pps != nil {
clientHalf = pps.LksClientHalf()
ppgen = pps.Generation()
} else if perr != nil {
return perr
} else {
return err
}
}
default:
return err
}
}
backupLks := libkb.NewLKSecWithClientHalf(clientHalf, ppgen, e.arg.Me.GetUID())
backupLks.SetServerHalf(libkb.NewLKSecServerHalfZeros())
ctext, err := backupLks.EncryptClientHalfRecovery(e.encKey)
if err != nil {
return err
}
if err := libkb.PostDeviceLKS(m, backupDev.ID, keybase1.DeviceTypeV2_PAPER, backupLks.GetServerHalf(), backupLks.Generation(), ctext, e.encKey.GetKID()); err != nil {
return err
}
// push the paper signing key
sigDel := libkb.Delegator{
NewKey: e.sigKey,
Expire: libkb.NaclEdDSAExpireIn,
Me: e.arg.Me,
Device: backupDev,
Contextified: libkb.NewContextified(e.G()),
}
if e.arg.IsEldest {
sigDel.DelegationType = libkb.DelegationTypeEldest
} else {
sigDel.DelegationType = libkb.DelegationTypeSibkey
sigDel.ExistingKey = e.arg.SigningKey
}
// push the paper encryption key
sigEnc := libkb.Delegator{
NewKey: e.encKey,
DelegationType: libkb.DelegationTypeSubkey,
Expire: libkb.NaclDHExpireIn,
ExistingKey: e.sigKey,
Me: e.arg.Me,
Device: backupDev,
Contextified: libkb.NewContextified(e.G()),
}
pukBoxes, err := e.makePerUserKeyBoxes(m)
if err != nil {
return err
}
m.Debug("PaperKeyGen#push running delegators")
return libkb.DelegatorAggregator(m, []libkb.Delegator{sigDel, sigEnc}, nil, pukBoxes, nil, nil)
}
func (e *PaperKeyGen) makePerUserKeyBoxes(m libkb.MetaContext) ([]keybase1.PerUserKeyBox, error) {
m.Debug("PaperKeyGen#makePerUserKeyBoxes")
var pukBoxes []keybase1.PerUserKeyBox
pukring, err := e.getPerUserKeyring(m)
if err != nil {
return nil, err
}
if pukring.HasAnyKeys() {
if e.arg.EncryptionKey.IsNil() {
return nil, errors.New("missing encryption key for creating paper key")
}
pukBox, err := pukring.PrepareBoxForNewDevice(m,
e.encKey, // receiver key: new paper key enc
e.arg.EncryptionKey) // sender key: this device enc
if err != nil {
return nil, err
}
pukBoxes = append(pukBoxes, pukBox)
}
m.Debug("PaperKeyGen#makePerUserKeyBoxes -> %v", len(pukBoxes))
return pukBoxes, nil
}
func (e *PaperKeyGen) getPerUserKeyring(mctx libkb.MetaContext) (ret *libkb.PerUserKeyring, err error) {
ret = e.arg.PerUserKeyring
if ret != nil {
return
}
ret, err = e.G().GetPerUserKeyring(mctx.Ctx())
return
}