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
|
From f32a31fd6279114af604a1b4cc33af8d377d2e29 Mon Sep 17 00:00:00 2001
From: John Lane <john@lane.uk.net>
Date: Fri, 26 Jun 2015 13:49:58 +0100
Subject: [PATCH 3/6] Cryptomount luks allow multiple passphrase attempts
---
grub-core/disk/luks.c | 278 ++++++++++++++++++++++++++------------------------
1 file changed, 143 insertions(+), 135 deletions(-)
diff --git a/grub-core/disk/luks.c b/grub-core/disk/luks.c
index 5882368..11e437e 100644
--- a/grub-core/disk/luks.c
+++ b/grub-core/disk/luks.c
@@ -321,10 +321,10 @@ configure_ciphers (grub_disk_t disk, const char *check_uuid,
static grub_err_t
luks_recover_key (grub_disk_t source,
- grub_cryptodisk_t dev,
- grub_file_t hdr,
- grub_uint8_t *keyfile_bytes,
- grub_size_t keyfile_bytes_size)
+ grub_cryptodisk_t dev,
+ grub_file_t hdr,
+ grub_uint8_t *keyfile_bytes,
+ grub_size_t keyfile_bytes_size)
{
struct grub_luks_phdr header;
grub_size_t keysize;
@@ -339,6 +339,7 @@ luks_recover_key (grub_disk_t source,
grub_size_t max_stripes = 1;
char *tmp;
grub_uint32_t sector;
+ unsigned attempts = 2;
err = GRUB_ERR_NONE;
@@ -361,151 +362,158 @@ luks_recover_key (grub_disk_t source,
for (i = 0; i < ARRAY_SIZE (header.keyblock); i++)
if (grub_be_to_cpu32 (header.keyblock[i].active) == LUKS_KEY_ENABLED
- && grub_be_to_cpu32 (header.keyblock[i].stripes) > max_stripes)
+ && grub_be_to_cpu32 (header.keyblock[i].stripes) > max_stripes)
max_stripes = grub_be_to_cpu32 (header.keyblock[i].stripes);
split_key = grub_malloc (keysize * max_stripes);
if (!split_key)
return grub_errno;
- if (keyfile_bytes)
+ while (attempts)
{
- /* Use bytestring from key file as passphrase */
- passphrase = keyfile_bytes;
- passphrase_length = keyfile_bytes_size;
- }
- else
- {
- /* Get the passphrase from the user. */
- tmp = NULL;
- if (source->partition)
- tmp = grub_partition_get_name (source->partition);
- grub_printf_ (N_("Enter passphrase for %s%s%s (%s): "), source->name,
- source->partition ? "," : "", tmp ? : "", dev->uuid);
- grub_free (tmp);
- if (!grub_password_get (interactive_passphrase, MAX_PASSPHRASE))
+ if (keyfile_bytes)
{
- grub_free (split_key);
- return grub_error (GRUB_ERR_BAD_ARGUMENT, "Passphrase not supplied");
- }
-
- passphrase = (grub_uint8_t *)interactive_passphrase;
- passphrase_length = grub_strlen (interactive_passphrase);
-
- }
-
- /* Try to recover master key from each active keyslot. */
- for (i = 0; i < ARRAY_SIZE (header.keyblock); i++)
- {
- gcry_err_code_t gcry_err;
- grub_uint8_t candidate_key[GRUB_CRYPTODISK_MAX_KEYLEN];
- grub_uint8_t digest[GRUB_CRYPTODISK_MAX_KEYLEN];
-
- /* Check if keyslot is enabled. */
- if (grub_be_to_cpu32 (header.keyblock[i].active) != LUKS_KEY_ENABLED)
- continue;
-
- grub_dprintf ("luks", "Trying keyslot %d\n", i);
-
- /* Calculate the PBKDF2 of the user supplied passphrase. */
- gcry_err = grub_crypto_pbkdf2 (dev->hash, (grub_uint8_t *) passphrase,
- passphrase_length,
- header.keyblock[i].passwordSalt,
- sizeof (header.keyblock[i].passwordSalt),
- grub_be_to_cpu32 (header.keyblock[i].
- passwordIterations),
- digest, keysize);
-
- if (gcry_err)
- {
- grub_free (split_key);
- return grub_crypto_gcry_error (gcry_err);
- }
-
- grub_dprintf ("luks", "PBKDF2 done\n");
-
- gcry_err = grub_cryptodisk_setkey (dev, digest, keysize);
- if (gcry_err)
- {
- grub_free (split_key);
- return grub_crypto_gcry_error (gcry_err);
- }
-
- sector = grub_be_to_cpu32 (header.keyblock[i].keyMaterialOffset);
- length = (keysize * grub_be_to_cpu32 (header.keyblock[i].stripes));
-
- /* Read and decrypt the key material from the disk. */
- if (hdr)
- {
- grub_file_seek (hdr, sector * 512);
- if (grub_file_read (hdr, split_key, length) != (grub_ssize_t)length)
- err = GRUB_ERR_READ_ERROR;
+ /* Use bytestring from key file as passphrase */
+ passphrase = keyfile_bytes;
+ passphrase_length = keyfile_bytes_size;
+ keyfile_bytes = NULL; /* use it only once */
}
else
- err = grub_disk_read (source, sector, 0, length, split_key);
- if (err)
- {
- grub_free (split_key);
- return err;
- }
-
- gcry_err = grub_cryptodisk_decrypt (dev, split_key, length, 0);
- if (gcry_err)
- {
- grub_free (split_key);
- return grub_crypto_gcry_error (gcry_err);
- }
-
- /* Merge the decrypted key material to get the candidate master key. */
- gcry_err = AF_merge (dev->hash, split_key, candidate_key, keysize,
- grub_be_to_cpu32 (header.keyblock[i].stripes));
- if (gcry_err)
- {
- grub_free (split_key);
- return grub_crypto_gcry_error (gcry_err);
- }
-
- grub_dprintf ("luks", "candidate key recovered\n");
-
- /* Calculate the PBKDF2 of the candidate master key. */
- gcry_err = grub_crypto_pbkdf2 (dev->hash, candidate_key,
- grub_be_to_cpu32 (header.keyBytes),
- header.mkDigestSalt,
- sizeof (header.mkDigestSalt),
- grub_be_to_cpu32
- (header.mkDigestIterations),
- candidate_digest,
- sizeof (candidate_digest));
- if (gcry_err)
- {
- grub_free (split_key);
- return grub_crypto_gcry_error (gcry_err);
- }
-
- /* Compare the calculated PBKDF2 to the digest stored
- in the header to see if it's correct. */
- if (grub_memcmp (candidate_digest, header.mkDigest,
- sizeof (header.mkDigest)) != 0)
- {
- grub_dprintf ("luks", "bad digest\n");
- continue;
- }
+ {
+ /* Get the passphrase from the user. */
+ tmp = NULL;
+ if (source->partition)
+ tmp = grub_partition_get_name (source->partition);
+ grub_printf_ (N_("Enter passphrase for %s%s%s (%s): "), source->name,
+ source->partition ? "," : "", tmp ? : "", dev->uuid);
+ grub_free (tmp);
+ if (!grub_password_get (interactive_passphrase, MAX_PASSPHRASE))
+ {
+ grub_free (split_key);
+ return grub_error (GRUB_ERR_BAD_ARGUMENT, "Passphrase not supplied");
+ }
+
+ passphrase = (grub_uint8_t *)interactive_passphrase;
+ passphrase_length = grub_strlen (interactive_passphrase);
- /* TRANSLATORS: It's a cryptographic key slot: one element of an array
- where each element is either empty or holds a key. */
- grub_printf_ (N_("Slot %d opened\n"), i);
+ }
- /* Set the master key. */
- gcry_err = grub_cryptodisk_setkey (dev, candidate_key, keysize);
- if (gcry_err)
- {
- grub_free (split_key);
- return grub_crypto_gcry_error (gcry_err);
- }
+ /* Try to recover master key from each active keyslot. */
+ for (i = 0; i < ARRAY_SIZE (header.keyblock); i++)
+ {
+ gcry_err_code_t gcry_err;
+ grub_uint8_t candidate_key[GRUB_CRYPTODISK_MAX_KEYLEN];
+ grub_uint8_t digest[GRUB_CRYPTODISK_MAX_KEYLEN];
+
+ /* Check if keyslot is enabled. */
+ if (grub_be_to_cpu32 (header.keyblock[i].active) != LUKS_KEY_ENABLED)
+ continue;
+
+ grub_dprintf ("luks", "Trying keyslot %d\n", i);
+
+ /* Calculate the PBKDF2 of the user supplied passphrase. */
+ gcry_err = grub_crypto_pbkdf2 (dev->hash, (grub_uint8_t *) passphrase,
+ passphrase_length,
+ header.keyblock[i].passwordSalt,
+ sizeof (header.keyblock[i].passwordSalt),
+ grub_be_to_cpu32 (header.keyblock[i].
+ passwordIterations),
+ digest, keysize);
+
+ if (gcry_err)
+ {
+ grub_free (split_key);
+ return grub_crypto_gcry_error (gcry_err);
+ }
+
+ grub_dprintf ("luks", "PBKDF2 done\n");
+
+ gcry_err = grub_cryptodisk_setkey (dev, digest, keysize);
+ if (gcry_err)
+ {
+ grub_free (split_key);
+ return grub_crypto_gcry_error (gcry_err);
+ }
+
+ sector = grub_be_to_cpu32 (header.keyblock[i].keyMaterialOffset);
+ length = (keysize * grub_be_to_cpu32 (header.keyblock[i].stripes));
+
+ /* Read and decrypt the key material from the disk. */
+ if (hdr)
+ {
+ grub_file_seek (hdr, sector * 512);
+ if (grub_file_read (hdr, split_key, length) != (grub_ssize_t)length)
+ err = GRUB_ERR_READ_ERROR;
+ }
+ else
+ err = grub_disk_read (source, sector, 0, length, split_key);
+ if (err)
+ {
+ grub_free (split_key);
+ return err;
+ }
+
+ gcry_err = grub_cryptodisk_decrypt (dev, split_key, length, 0);
+ if (gcry_err)
+ {
+ grub_free (split_key);
+ return grub_crypto_gcry_error (gcry_err);
+ }
+
+ /* Merge the decrypted key material to get the candidate master key. */
+ gcry_err = AF_merge (dev->hash, split_key, candidate_key, keysize,
+ grub_be_to_cpu32 (header.keyblock[i].stripes));
+ if (gcry_err)
+ {
+ grub_free (split_key);
+ return grub_crypto_gcry_error (gcry_err);
+ }
+
+ grub_dprintf ("luks", "candidate key recovered\n");
+
+ /* Calculate the PBKDF2 of the candidate master key. */
+ gcry_err = grub_crypto_pbkdf2 (dev->hash, candidate_key,
+ grub_be_to_cpu32 (header.keyBytes),
+ header.mkDigestSalt,
+ sizeof (header.mkDigestSalt),
+ grub_be_to_cpu32
+ (header.mkDigestIterations),
+ candidate_digest,
+ sizeof (candidate_digest));
+ if (gcry_err)
+ {
+ grub_free (split_key);
+ return grub_crypto_gcry_error (gcry_err);
+ }
+
+ /* Compare the calculated PBKDF2 to the digest stored
+ in the header to see if it's correct. */
+ if (grub_memcmp (candidate_digest, header.mkDigest,
+ sizeof (header.mkDigest)) != 0)
+ {
+ grub_dprintf ("luks", "bad digest\n");
+ continue;
+ }
+
+ /* TRANSLATORS: It's a cryptographic key slot: one element of an array
+ where each element is either empty or holds a key. */
+ grub_printf_ (N_("Slot %d opened\n"), i);
+
+ /* Set the master key. */
+ gcry_err = grub_cryptodisk_setkey (dev, candidate_key, keysize);
+ if (gcry_err)
+ {
+ grub_free (split_key);
+ return grub_crypto_gcry_error (gcry_err);
+ }
- grub_free (split_key);
+ grub_free (split_key);
- return GRUB_ERR_NONE;
+ return GRUB_ERR_NONE;
+ }
+ grub_printf_ (N_("Failed to decrypt master key.\n"));
+ if (--attempts) grub_printf_ (N_("%u attempt%s remaining.\n"), attempts,
+ (attempts==1) ? "" : "s");
}
grub_free (split_key);
--
1.9.1
|
