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keystore.c
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1 
28 #include <linux/string.h>
29 #include <linux/syscalls.h>
30 #include <linux/pagemap.h>
31 #include <linux/key.h>
32 #include <linux/random.h>
33 #include <linux/crypto.h>
34 #include <linux/scatterlist.h>
35 #include <linux/slab.h>
36 #include "ecryptfs_kernel.h"
37 
43 static int process_request_key_err(long err_code)
44 {
45  int rc = 0;
46 
47  switch (err_code) {
48  case -ENOKEY:
49  ecryptfs_printk(KERN_WARNING, "No key\n");
50  rc = -ENOENT;
51  break;
52  case -EKEYEXPIRED:
53  ecryptfs_printk(KERN_WARNING, "Key expired\n");
54  rc = -ETIME;
55  break;
56  case -EKEYREVOKED:
57  ecryptfs_printk(KERN_WARNING, "Key revoked\n");
58  rc = -EINVAL;
59  break;
60  default:
61  ecryptfs_printk(KERN_WARNING, "Unknown error code: "
62  "[0x%.16lx]\n", err_code);
63  rc = -EINVAL;
64  }
65  return rc;
66 }
67 
68 static int process_find_global_auth_tok_for_sig_err(int err_code)
69 {
70  int rc = err_code;
71 
72  switch (err_code) {
73  case -ENOENT:
74  ecryptfs_printk(KERN_WARNING, "Missing auth tok\n");
75  break;
76  case -EINVAL:
77  ecryptfs_printk(KERN_WARNING, "Invalid auth tok\n");
78  break;
79  default:
80  rc = process_request_key_err(err_code);
81  break;
82  }
83  return rc;
84 }
85 
95 int ecryptfs_parse_packet_length(unsigned char *data, size_t *size,
96  size_t *length_size)
97 {
98  int rc = 0;
99 
100  (*length_size) = 0;
101  (*size) = 0;
102  if (data[0] < 192) {
103  /* One-byte length */
104  (*size) = (unsigned char)data[0];
105  (*length_size) = 1;
106  } else if (data[0] < 224) {
107  /* Two-byte length */
108  (*size) = (((unsigned char)(data[0]) - 192) * 256);
109  (*size) += ((unsigned char)(data[1]) + 192);
110  (*length_size) = 2;
111  } else if (data[0] == 255) {
112  /* If support is added, adjust ECRYPTFS_MAX_PKT_LEN_SIZE */
113  ecryptfs_printk(KERN_ERR, "Five-byte packet length not "
114  "supported\n");
115  rc = -EINVAL;
116  goto out;
117  } else {
118  ecryptfs_printk(KERN_ERR, "Error parsing packet length\n");
119  rc = -EINVAL;
120  goto out;
121  }
122 out:
123  return rc;
124 }
125 
136 int ecryptfs_write_packet_length(char *dest, size_t size,
137  size_t *packet_size_length)
138 {
139  int rc = 0;
140 
141  if (size < 192) {
142  dest[0] = size;
143  (*packet_size_length) = 1;
144  } else if (size < 65536) {
145  dest[0] = (((size - 192) / 256) + 192);
146  dest[1] = ((size - 192) % 256);
147  (*packet_size_length) = 2;
148  } else {
149  /* If support is added, adjust ECRYPTFS_MAX_PKT_LEN_SIZE */
150  rc = -EINVAL;
151  ecryptfs_printk(KERN_WARNING,
152  "Unsupported packet size: [%zd]\n", size);
153  }
154  return rc;
155 }
156 
157 static int
158 write_tag_64_packet(char *signature, struct ecryptfs_session_key *session_key,
159  char **packet, size_t *packet_len)
160 {
161  size_t i = 0;
162  size_t data_len;
163  size_t packet_size_len;
164  char *message;
165  int rc;
166 
167  /*
168  * ***** TAG 64 Packet Format *****
169  * | Content Type | 1 byte |
170  * | Key Identifier Size | 1 or 2 bytes |
171  * | Key Identifier | arbitrary |
172  * | Encrypted File Encryption Key Size | 1 or 2 bytes |
173  * | Encrypted File Encryption Key | arbitrary |
174  */
175  data_len = (5 + ECRYPTFS_SIG_SIZE_HEX
176  + session_key->encrypted_key_size);
177  *packet = kmalloc(data_len, GFP_KERNEL);
178  message = *packet;
179  if (!message) {
180  ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n");
181  rc = -ENOMEM;
182  goto out;
183  }
184  message[i++] = ECRYPTFS_TAG_64_PACKET_TYPE;
185  rc = ecryptfs_write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX,
186  &packet_size_len);
187  if (rc) {
188  ecryptfs_printk(KERN_ERR, "Error generating tag 64 packet "
189  "header; cannot generate packet length\n");
190  goto out;
191  }
192  i += packet_size_len;
193  memcpy(&message[i], signature, ECRYPTFS_SIG_SIZE_HEX);
194  i += ECRYPTFS_SIG_SIZE_HEX;
195  rc = ecryptfs_write_packet_length(&message[i],
196  session_key->encrypted_key_size,
197  &packet_size_len);
198  if (rc) {
199  ecryptfs_printk(KERN_ERR, "Error generating tag 64 packet "
200  "header; cannot generate packet length\n");
201  goto out;
202  }
203  i += packet_size_len;
204  memcpy(&message[i], session_key->encrypted_key,
205  session_key->encrypted_key_size);
206  i += session_key->encrypted_key_size;
207  *packet_len = i;
208 out:
209  return rc;
210 }
211 
212 static int
213 parse_tag_65_packet(struct ecryptfs_session_key *session_key, u8 *cipher_code,
214  struct ecryptfs_message *msg)
215 {
216  size_t i = 0;
217  char *data;
218  size_t data_len;
219  size_t m_size;
220  size_t message_len;
221  u16 checksum = 0;
222  u16 expected_checksum = 0;
223  int rc;
224 
225  /*
226  * ***** TAG 65 Packet Format *****
227  * | Content Type | 1 byte |
228  * | Status Indicator | 1 byte |
229  * | File Encryption Key Size | 1 or 2 bytes |
230  * | File Encryption Key | arbitrary |
231  */
232  message_len = msg->data_len;
233  data = msg->data;
234  if (message_len < 4) {
235  rc = -EIO;
236  goto out;
237  }
238  if (data[i++] != ECRYPTFS_TAG_65_PACKET_TYPE) {
239  ecryptfs_printk(KERN_ERR, "Type should be ECRYPTFS_TAG_65\n");
240  rc = -EIO;
241  goto out;
242  }
243  if (data[i++]) {
244  ecryptfs_printk(KERN_ERR, "Status indicator has non-zero value "
245  "[%d]\n", data[i-1]);
246  rc = -EIO;
247  goto out;
248  }
249  rc = ecryptfs_parse_packet_length(&data[i], &m_size, &data_len);
250  if (rc) {
251  ecryptfs_printk(KERN_WARNING, "Error parsing packet length; "
252  "rc = [%d]\n", rc);
253  goto out;
254  }
255  i += data_len;
256  if (message_len < (i + m_size)) {
257  ecryptfs_printk(KERN_ERR, "The message received from ecryptfsd "
258  "is shorter than expected\n");
259  rc = -EIO;
260  goto out;
261  }
262  if (m_size < 3) {
263  ecryptfs_printk(KERN_ERR,
264  "The decrypted key is not long enough to "
265  "include a cipher code and checksum\n");
266  rc = -EIO;
267  goto out;
268  }
269  *cipher_code = data[i++];
270  /* The decrypted key includes 1 byte cipher code and 2 byte checksum */
271  session_key->decrypted_key_size = m_size - 3;
272  if (session_key->decrypted_key_size > ECRYPTFS_MAX_KEY_BYTES) {
273  ecryptfs_printk(KERN_ERR, "key_size [%d] larger than "
274  "the maximum key size [%d]\n",
275  session_key->decrypted_key_size,
276  ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES);
277  rc = -EIO;
278  goto out;
279  }
280  memcpy(session_key->decrypted_key, &data[i],
281  session_key->decrypted_key_size);
282  i += session_key->decrypted_key_size;
283  expected_checksum += (unsigned char)(data[i++]) << 8;
284  expected_checksum += (unsigned char)(data[i++]);
285  for (i = 0; i < session_key->decrypted_key_size; i++)
286  checksum += session_key->decrypted_key[i];
287  if (expected_checksum != checksum) {
288  ecryptfs_printk(KERN_ERR, "Invalid checksum for file "
289  "encryption key; expected [%x]; calculated "
290  "[%x]\n", expected_checksum, checksum);
291  rc = -EIO;
292  }
293 out:
294  return rc;
295 }
296 
297 
298 static int
299 write_tag_66_packet(char *signature, u8 cipher_code,
300  struct ecryptfs_crypt_stat *crypt_stat, char **packet,
301  size_t *packet_len)
302 {
303  size_t i = 0;
304  size_t j;
305  size_t data_len;
306  size_t checksum = 0;
307  size_t packet_size_len;
308  char *message;
309  int rc;
310 
311  /*
312  * ***** TAG 66 Packet Format *****
313  * | Content Type | 1 byte |
314  * | Key Identifier Size | 1 or 2 bytes |
315  * | Key Identifier | arbitrary |
316  * | File Encryption Key Size | 1 or 2 bytes |
317  * | File Encryption Key | arbitrary |
318  */
319  data_len = (5 + ECRYPTFS_SIG_SIZE_HEX + crypt_stat->key_size);
320  *packet = kmalloc(data_len, GFP_KERNEL);
321  message = *packet;
322  if (!message) {
323  ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n");
324  rc = -ENOMEM;
325  goto out;
326  }
327  message[i++] = ECRYPTFS_TAG_66_PACKET_TYPE;
328  rc = ecryptfs_write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX,
329  &packet_size_len);
330  if (rc) {
331  ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet "
332  "header; cannot generate packet length\n");
333  goto out;
334  }
335  i += packet_size_len;
336  memcpy(&message[i], signature, ECRYPTFS_SIG_SIZE_HEX);
337  i += ECRYPTFS_SIG_SIZE_HEX;
338  /* The encrypted key includes 1 byte cipher code and 2 byte checksum */
339  rc = ecryptfs_write_packet_length(&message[i], crypt_stat->key_size + 3,
340  &packet_size_len);
341  if (rc) {
342  ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet "
343  "header; cannot generate packet length\n");
344  goto out;
345  }
346  i += packet_size_len;
347  message[i++] = cipher_code;
348  memcpy(&message[i], crypt_stat->key, crypt_stat->key_size);
349  i += crypt_stat->key_size;
350  for (j = 0; j < crypt_stat->key_size; j++)
351  checksum += crypt_stat->key[j];
352  message[i++] = (checksum / 256) % 256;
353  message[i++] = (checksum % 256);
354  *packet_len = i;
355 out:
356  return rc;
357 }
358 
359 static int
360 parse_tag_67_packet(struct ecryptfs_key_record *key_rec,
361  struct ecryptfs_message *msg)
362 {
363  size_t i = 0;
364  char *data;
365  size_t data_len;
366  size_t message_len;
367  int rc;
368 
369  /*
370  * ***** TAG 65 Packet Format *****
371  * | Content Type | 1 byte |
372  * | Status Indicator | 1 byte |
373  * | Encrypted File Encryption Key Size | 1 or 2 bytes |
374  * | Encrypted File Encryption Key | arbitrary |
375  */
376  message_len = msg->data_len;
377  data = msg->data;
378  /* verify that everything through the encrypted FEK size is present */
379  if (message_len < 4) {
380  rc = -EIO;
381  printk(KERN_ERR "%s: message_len is [%zd]; minimum acceptable "
382  "message length is [%d]\n", __func__, message_len, 4);
383  goto out;
384  }
385  if (data[i++] != ECRYPTFS_TAG_67_PACKET_TYPE) {
386  rc = -EIO;
387  printk(KERN_ERR "%s: Type should be ECRYPTFS_TAG_67\n",
388  __func__);
389  goto out;
390  }
391  if (data[i++]) {
392  rc = -EIO;
393  printk(KERN_ERR "%s: Status indicator has non zero "
394  "value [%d]\n", __func__, data[i-1]);
395 
396  goto out;
397  }
398  rc = ecryptfs_parse_packet_length(&data[i], &key_rec->enc_key_size,
399  &data_len);
400  if (rc) {
401  ecryptfs_printk(KERN_WARNING, "Error parsing packet length; "
402  "rc = [%d]\n", rc);
403  goto out;
404  }
405  i += data_len;
406  if (message_len < (i + key_rec->enc_key_size)) {
407  rc = -EIO;
408  printk(KERN_ERR "%s: message_len [%zd]; max len is [%zd]\n",
409  __func__, message_len, (i + key_rec->enc_key_size));
410  goto out;
411  }
412  if (key_rec->enc_key_size > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
413  rc = -EIO;
414  printk(KERN_ERR "%s: Encrypted key_size [%zd] larger than "
415  "the maximum key size [%d]\n", __func__,
416  key_rec->enc_key_size,
417  ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES);
418  goto out;
419  }
420  memcpy(key_rec->enc_key, &data[i], key_rec->enc_key_size);
421 out:
422  return rc;
423 }
424 
431 static int ecryptfs_verify_version(u16 version)
432 {
433  int rc = 0;
434  unsigned char major;
435  unsigned char minor;
436 
437  major = ((version >> 8) & 0xFF);
438  minor = (version & 0xFF);
439  if (major != ECRYPTFS_VERSION_MAJOR) {
440  ecryptfs_printk(KERN_ERR, "Major version number mismatch. "
441  "Expected [%d]; got [%d]\n",
442  ECRYPTFS_VERSION_MAJOR, major);
443  rc = -EINVAL;
444  goto out;
445  }
446  if (minor != ECRYPTFS_VERSION_MINOR) {
447  ecryptfs_printk(KERN_ERR, "Minor version number mismatch. "
448  "Expected [%d]; got [%d]\n",
449  ECRYPTFS_VERSION_MINOR, minor);
450  rc = -EINVAL;
451  goto out;
452  }
453 out:
454  return rc;
455 }
456 
464 static int
465 ecryptfs_verify_auth_tok_from_key(struct key *auth_tok_key,
466  struct ecryptfs_auth_tok **auth_tok)
467 {
468  int rc = 0;
469 
470  (*auth_tok) = ecryptfs_get_key_payload_data(auth_tok_key);
471  if (ecryptfs_verify_version((*auth_tok)->version)) {
472  printk(KERN_ERR "Data structure version mismatch. Userspace "
473  "tools must match eCryptfs kernel module with major "
474  "version [%d] and minor version [%d]\n",
475  ECRYPTFS_VERSION_MAJOR, ECRYPTFS_VERSION_MINOR);
476  rc = -EINVAL;
477  goto out;
478  }
479  if ((*auth_tok)->token_type != ECRYPTFS_PASSWORD
480  && (*auth_tok)->token_type != ECRYPTFS_PRIVATE_KEY) {
481  printk(KERN_ERR "Invalid auth_tok structure "
482  "returned from key query\n");
483  rc = -EINVAL;
484  goto out;
485  }
486 out:
487  return rc;
488 }
489 
490 static int
491 ecryptfs_find_global_auth_tok_for_sig(
492  struct key **auth_tok_key,
493  struct ecryptfs_auth_tok **auth_tok,
494  struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig)
495 {
496  struct ecryptfs_global_auth_tok *walker;
497  int rc = 0;
498 
499  (*auth_tok_key) = NULL;
500  (*auth_tok) = NULL;
501  mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
502  list_for_each_entry(walker,
503  &mount_crypt_stat->global_auth_tok_list,
504  mount_crypt_stat_list) {
505  if (memcmp(walker->sig, sig, ECRYPTFS_SIG_SIZE_HEX))
506  continue;
507 
508  if (walker->flags & ECRYPTFS_AUTH_TOK_INVALID) {
509  rc = -EINVAL;
510  goto out;
511  }
512 
513  rc = key_validate(walker->global_auth_tok_key);
514  if (rc) {
515  if (rc == -EKEYEXPIRED)
516  goto out;
517  goto out_invalid_auth_tok;
518  }
519 
520  down_write(&(walker->global_auth_tok_key->sem));
521  rc = ecryptfs_verify_auth_tok_from_key(
522  walker->global_auth_tok_key, auth_tok);
523  if (rc)
524  goto out_invalid_auth_tok_unlock;
525 
526  (*auth_tok_key) = walker->global_auth_tok_key;
527  key_get(*auth_tok_key);
528  goto out;
529  }
530  rc = -ENOENT;
531  goto out;
532 out_invalid_auth_tok_unlock:
533  up_write(&(walker->global_auth_tok_key->sem));
534 out_invalid_auth_tok:
535  printk(KERN_WARNING "Invalidating auth tok with sig = [%s]\n", sig);
536  walker->flags |= ECRYPTFS_AUTH_TOK_INVALID;
537  key_put(walker->global_auth_tok_key);
538  walker->global_auth_tok_key = NULL;
539 out:
540  mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
541  return rc;
542 }
543 
559 static int
560 ecryptfs_find_auth_tok_for_sig(
561  struct key **auth_tok_key,
562  struct ecryptfs_auth_tok **auth_tok,
563  struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
564  char *sig)
565 {
566  int rc = 0;
567 
568  rc = ecryptfs_find_global_auth_tok_for_sig(auth_tok_key, auth_tok,
569  mount_crypt_stat, sig);
570  if (rc == -ENOENT) {
571  /* if the flag ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY is set in the
572  * mount_crypt_stat structure, we prevent to use auth toks that
573  * are not inserted through the ecryptfs_add_global_auth_tok
574  * function.
575  */
576  if (mount_crypt_stat->flags
577  & ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY)
578  return -EINVAL;
579 
580  rc = ecryptfs_keyring_auth_tok_for_sig(auth_tok_key, auth_tok,
581  sig);
582  }
583  return rc;
584 }
585 
591 struct ecryptfs_write_tag_70_packet_silly_stack {
592  u8 cipher_code;
593  size_t max_packet_size;
594  size_t packet_size_len;
595  size_t block_aligned_filename_size;
596  size_t block_size;
597  size_t i;
598  size_t j;
599  size_t num_rand_bytes;
600  struct mutex *tfm_mutex;
601  char *block_aligned_filename;
602  struct ecryptfs_auth_tok *auth_tok;
603  struct scatterlist src_sg[2];
604  struct scatterlist dst_sg[2];
605  struct blkcipher_desc desc;
606  char iv[ECRYPTFS_MAX_IV_BYTES];
607  char hash[ECRYPTFS_TAG_70_DIGEST_SIZE];
608  char tmp_hash[ECRYPTFS_TAG_70_DIGEST_SIZE];
609  struct hash_desc hash_desc;
610  struct scatterlist hash_sg;
611 };
612 
623 int
624 ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes,
625  size_t *packet_size,
626  struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
627  char *filename, size_t filename_size)
628 {
629  struct ecryptfs_write_tag_70_packet_silly_stack *s;
630  struct key *auth_tok_key = NULL;
631  int rc = 0;
632 
633  s = kmalloc(sizeof(*s), GFP_KERNEL);
634  if (!s) {
635  printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc "
636  "[%zd] bytes of kernel memory\n", __func__, sizeof(*s));
637  rc = -ENOMEM;
638  goto out;
639  }
640  s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
641  (*packet_size) = 0;
642  rc = ecryptfs_find_auth_tok_for_sig(
643  &auth_tok_key,
644  &s->auth_tok, mount_crypt_stat,
645  mount_crypt_stat->global_default_fnek_sig);
646  if (rc) {
647  printk(KERN_ERR "%s: Error attempting to find auth tok for "
648  "fnek sig [%s]; rc = [%d]\n", __func__,
649  mount_crypt_stat->global_default_fnek_sig, rc);
650  goto out;
651  }
652  rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(
653  &s->desc.tfm,
654  &s->tfm_mutex, mount_crypt_stat->global_default_fn_cipher_name);
655  if (unlikely(rc)) {
656  printk(KERN_ERR "Internal error whilst attempting to get "
657  "tfm and mutex for cipher name [%s]; rc = [%d]\n",
658  mount_crypt_stat->global_default_fn_cipher_name, rc);
659  goto out;
660  }
661  mutex_lock(s->tfm_mutex);
662  s->block_size = crypto_blkcipher_blocksize(s->desc.tfm);
663  /* Plus one for the \0 separator between the random prefix
664  * and the plaintext filename */
665  s->num_rand_bytes = (ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES + 1);
666  s->block_aligned_filename_size = (s->num_rand_bytes + filename_size);
667  if ((s->block_aligned_filename_size % s->block_size) != 0) {
668  s->num_rand_bytes += (s->block_size
669  - (s->block_aligned_filename_size
670  % s->block_size));
671  s->block_aligned_filename_size = (s->num_rand_bytes
672  + filename_size);
673  }
674  /* Octet 0: Tag 70 identifier
675  * Octets 1-N1: Tag 70 packet size (includes cipher identifier
676  * and block-aligned encrypted filename size)
677  * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE)
678  * Octet N2-N3: Cipher identifier (1 octet)
679  * Octets N3-N4: Block-aligned encrypted filename
680  * - Consists of a minimum number of random characters, a \0
681  * separator, and then the filename */
682  s->max_packet_size = (ECRYPTFS_TAG_70_MAX_METADATA_SIZE
683  + s->block_aligned_filename_size);
684  if (dest == NULL) {
685  (*packet_size) = s->max_packet_size;
686  goto out_unlock;
687  }
688  if (s->max_packet_size > (*remaining_bytes)) {
689  printk(KERN_WARNING "%s: Require [%zd] bytes to write; only "
690  "[%zd] available\n", __func__, s->max_packet_size,
691  (*remaining_bytes));
692  rc = -EINVAL;
693  goto out_unlock;
694  }
695  s->block_aligned_filename = kzalloc(s->block_aligned_filename_size,
696  GFP_KERNEL);
697  if (!s->block_aligned_filename) {
698  printk(KERN_ERR "%s: Out of kernel memory whilst attempting to "
699  "kzalloc [%zd] bytes\n", __func__,
700  s->block_aligned_filename_size);
701  rc = -ENOMEM;
702  goto out_unlock;
703  }
704  s->i = 0;
705  dest[s->i++] = ECRYPTFS_TAG_70_PACKET_TYPE;
706  rc = ecryptfs_write_packet_length(&dest[s->i],
707  (ECRYPTFS_SIG_SIZE
708  + 1 /* Cipher code */
709  + s->block_aligned_filename_size),
710  &s->packet_size_len);
711  if (rc) {
712  printk(KERN_ERR "%s: Error generating tag 70 packet "
713  "header; cannot generate packet length; rc = [%d]\n",
714  __func__, rc);
715  goto out_free_unlock;
716  }
717  s->i += s->packet_size_len;
718  ecryptfs_from_hex(&dest[s->i],
719  mount_crypt_stat->global_default_fnek_sig,
720  ECRYPTFS_SIG_SIZE);
721  s->i += ECRYPTFS_SIG_SIZE;
722  s->cipher_code = ecryptfs_code_for_cipher_string(
723  mount_crypt_stat->global_default_fn_cipher_name,
724  mount_crypt_stat->global_default_fn_cipher_key_bytes);
725  if (s->cipher_code == 0) {
726  printk(KERN_WARNING "%s: Unable to generate code for "
727  "cipher [%s] with key bytes [%zd]\n", __func__,
728  mount_crypt_stat->global_default_fn_cipher_name,
729  mount_crypt_stat->global_default_fn_cipher_key_bytes);
730  rc = -EINVAL;
731  goto out_free_unlock;
732  }
733  dest[s->i++] = s->cipher_code;
734  /* TODO: Support other key modules than passphrase for
735  * filename encryption */
736  if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) {
737  rc = -EOPNOTSUPP;
738  printk(KERN_INFO "%s: Filename encryption only supports "
739  "password tokens\n", __func__);
740  goto out_free_unlock;
741  }
742  sg_init_one(
743  &s->hash_sg,
744  (u8 *)s->auth_tok->token.password.session_key_encryption_key,
745  s->auth_tok->token.password.session_key_encryption_key_bytes);
746  s->hash_desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
747  s->hash_desc.tfm = crypto_alloc_hash(ECRYPTFS_TAG_70_DIGEST, 0,
748  CRYPTO_ALG_ASYNC);
749  if (IS_ERR(s->hash_desc.tfm)) {
750  rc = PTR_ERR(s->hash_desc.tfm);
751  printk(KERN_ERR "%s: Error attempting to "
752  "allocate hash crypto context; rc = [%d]\n",
753  __func__, rc);
754  goto out_free_unlock;
755  }
756  rc = crypto_hash_init(&s->hash_desc);
757  if (rc) {
758  printk(KERN_ERR
759  "%s: Error initializing crypto hash; rc = [%d]\n",
760  __func__, rc);
761  goto out_release_free_unlock;
762  }
763  rc = crypto_hash_update(
764  &s->hash_desc, &s->hash_sg,
765  s->auth_tok->token.password.session_key_encryption_key_bytes);
766  if (rc) {
767  printk(KERN_ERR
768  "%s: Error updating crypto hash; rc = [%d]\n",
769  __func__, rc);
770  goto out_release_free_unlock;
771  }
772  rc = crypto_hash_final(&s->hash_desc, s->hash);
773  if (rc) {
774  printk(KERN_ERR
775  "%s: Error finalizing crypto hash; rc = [%d]\n",
776  __func__, rc);
777  goto out_release_free_unlock;
778  }
779  for (s->j = 0; s->j < (s->num_rand_bytes - 1); s->j++) {
780  s->block_aligned_filename[s->j] =
781  s->hash[(s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)];
782  if ((s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)
783  == (ECRYPTFS_TAG_70_DIGEST_SIZE - 1)) {
784  sg_init_one(&s->hash_sg, (u8 *)s->hash,
785  ECRYPTFS_TAG_70_DIGEST_SIZE);
786  rc = crypto_hash_init(&s->hash_desc);
787  if (rc) {
788  printk(KERN_ERR
789  "%s: Error initializing crypto hash; "
790  "rc = [%d]\n", __func__, rc);
791  goto out_release_free_unlock;
792  }
793  rc = crypto_hash_update(&s->hash_desc, &s->hash_sg,
794  ECRYPTFS_TAG_70_DIGEST_SIZE);
795  if (rc) {
796  printk(KERN_ERR
797  "%s: Error updating crypto hash; "
798  "rc = [%d]\n", __func__, rc);
799  goto out_release_free_unlock;
800  }
801  rc = crypto_hash_final(&s->hash_desc, s->tmp_hash);
802  if (rc) {
803  printk(KERN_ERR
804  "%s: Error finalizing crypto hash; "
805  "rc = [%d]\n", __func__, rc);
806  goto out_release_free_unlock;
807  }
808  memcpy(s->hash, s->tmp_hash,
809  ECRYPTFS_TAG_70_DIGEST_SIZE);
810  }
811  if (s->block_aligned_filename[s->j] == '\0')
812  s->block_aligned_filename[s->j] = ECRYPTFS_NON_NULL;
813  }
814  memcpy(&s->block_aligned_filename[s->num_rand_bytes], filename,
815  filename_size);
816  rc = virt_to_scatterlist(s->block_aligned_filename,
817  s->block_aligned_filename_size, s->src_sg, 2);
818  if (rc < 1) {
819  printk(KERN_ERR "%s: Internal error whilst attempting to "
820  "convert filename memory to scatterlist; rc = [%d]. "
821  "block_aligned_filename_size = [%zd]\n", __func__, rc,
822  s->block_aligned_filename_size);
823  goto out_release_free_unlock;
824  }
825  rc = virt_to_scatterlist(&dest[s->i], s->block_aligned_filename_size,
826  s->dst_sg, 2);
827  if (rc < 1) {
828  printk(KERN_ERR "%s: Internal error whilst attempting to "
829  "convert encrypted filename memory to scatterlist; "
830  "rc = [%d]. block_aligned_filename_size = [%zd]\n",
831  __func__, rc, s->block_aligned_filename_size);
832  goto out_release_free_unlock;
833  }
834  /* The characters in the first block effectively do the job
835  * of the IV here, so we just use 0's for the IV. Note the
836  * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES
837  * >= ECRYPTFS_MAX_IV_BYTES. */
838  memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES);
839  s->desc.info = s->iv;
840  rc = crypto_blkcipher_setkey(
841  s->desc.tfm,
842  s->auth_tok->token.password.session_key_encryption_key,
843  mount_crypt_stat->global_default_fn_cipher_key_bytes);
844  if (rc < 0) {
845  printk(KERN_ERR "%s: Error setting key for crypto context; "
846  "rc = [%d]. s->auth_tok->token.password.session_key_"
847  "encryption_key = [0x%p]; mount_crypt_stat->"
848  "global_default_fn_cipher_key_bytes = [%zd]\n", __func__,
849  rc,
850  s->auth_tok->token.password.session_key_encryption_key,
851  mount_crypt_stat->global_default_fn_cipher_key_bytes);
852  goto out_release_free_unlock;
853  }
854  rc = crypto_blkcipher_encrypt_iv(&s->desc, s->dst_sg, s->src_sg,
855  s->block_aligned_filename_size);
856  if (rc) {
857  printk(KERN_ERR "%s: Error attempting to encrypt filename; "
858  "rc = [%d]\n", __func__, rc);
859  goto out_release_free_unlock;
860  }
861  s->i += s->block_aligned_filename_size;
862  (*packet_size) = s->i;
863  (*remaining_bytes) -= (*packet_size);
864 out_release_free_unlock:
865  crypto_free_hash(s->hash_desc.tfm);
866 out_free_unlock:
867  kzfree(s->block_aligned_filename);
868 out_unlock:
869  mutex_unlock(s->tfm_mutex);
870 out:
871  if (auth_tok_key) {
872  up_write(&(auth_tok_key->sem));
873  key_put(auth_tok_key);
874  }
875  kfree(s);
876  return rc;
877 }
878 
879 struct ecryptfs_parse_tag_70_packet_silly_stack {
880  u8 cipher_code;
881  size_t max_packet_size;
882  size_t packet_size_len;
883  size_t parsed_tag_70_packet_size;
884  size_t block_aligned_filename_size;
885  size_t block_size;
886  size_t i;
887  struct mutex *tfm_mutex;
888  char *decrypted_filename;
889  struct ecryptfs_auth_tok *auth_tok;
890  struct scatterlist src_sg[2];
891  struct scatterlist dst_sg[2];
892  struct blkcipher_desc desc;
893  char fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX + 1];
894  char iv[ECRYPTFS_MAX_IV_BYTES];
895  char cipher_string[ECRYPTFS_MAX_CIPHER_NAME_SIZE];
896 };
897 
913 int
914 ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size,
915  size_t *packet_size,
916  struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
917  char *data, size_t max_packet_size)
918 {
919  struct ecryptfs_parse_tag_70_packet_silly_stack *s;
920  struct key *auth_tok_key = NULL;
921  int rc = 0;
922 
923  (*packet_size) = 0;
924  (*filename_size) = 0;
925  (*filename) = NULL;
926  s = kmalloc(sizeof(*s), GFP_KERNEL);
927  if (!s) {
928  printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc "
929  "[%zd] bytes of kernel memory\n", __func__, sizeof(*s));
930  rc = -ENOMEM;
931  goto out;
932  }
933  s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
934  if (max_packet_size < ECRYPTFS_TAG_70_MIN_METADATA_SIZE) {
935  printk(KERN_WARNING "%s: max_packet_size is [%zd]; it must be "
936  "at least [%d]\n", __func__, max_packet_size,
937  ECRYPTFS_TAG_70_MIN_METADATA_SIZE);
938  rc = -EINVAL;
939  goto out;
940  }
941  /* Octet 0: Tag 70 identifier
942  * Octets 1-N1: Tag 70 packet size (includes cipher identifier
943  * and block-aligned encrypted filename size)
944  * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE)
945  * Octet N2-N3: Cipher identifier (1 octet)
946  * Octets N3-N4: Block-aligned encrypted filename
947  * - Consists of a minimum number of random numbers, a \0
948  * separator, and then the filename */
949  if (data[(*packet_size)++] != ECRYPTFS_TAG_70_PACKET_TYPE) {
950  printk(KERN_WARNING "%s: Invalid packet tag [0x%.2x]; must be "
951  "tag [0x%.2x]\n", __func__,
952  data[((*packet_size) - 1)], ECRYPTFS_TAG_70_PACKET_TYPE);
953  rc = -EINVAL;
954  goto out;
955  }
956  rc = ecryptfs_parse_packet_length(&data[(*packet_size)],
957  &s->parsed_tag_70_packet_size,
958  &s->packet_size_len);
959  if (rc) {
960  printk(KERN_WARNING "%s: Error parsing packet length; "
961  "rc = [%d]\n", __func__, rc);
962  goto out;
963  }
964  s->block_aligned_filename_size = (s->parsed_tag_70_packet_size
965  - ECRYPTFS_SIG_SIZE - 1);
966  if ((1 + s->packet_size_len + s->parsed_tag_70_packet_size)
967  > max_packet_size) {
968  printk(KERN_WARNING "%s: max_packet_size is [%zd]; real packet "
969  "size is [%zd]\n", __func__, max_packet_size,
970  (1 + s->packet_size_len + 1
971  + s->block_aligned_filename_size));
972  rc = -EINVAL;
973  goto out;
974  }
975  (*packet_size) += s->packet_size_len;
976  ecryptfs_to_hex(s->fnek_sig_hex, &data[(*packet_size)],
977  ECRYPTFS_SIG_SIZE);
978  s->fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX] = '\0';
979  (*packet_size) += ECRYPTFS_SIG_SIZE;
980  s->cipher_code = data[(*packet_size)++];
981  rc = ecryptfs_cipher_code_to_string(s->cipher_string, s->cipher_code);
982  if (rc) {
983  printk(KERN_WARNING "%s: Cipher code [%d] is invalid\n",
984  __func__, s->cipher_code);
985  goto out;
986  }
987  rc = ecryptfs_find_auth_tok_for_sig(&auth_tok_key,
988  &s->auth_tok, mount_crypt_stat,
989  s->fnek_sig_hex);
990  if (rc) {
991  printk(KERN_ERR "%s: Error attempting to find auth tok for "
992  "fnek sig [%s]; rc = [%d]\n", __func__, s->fnek_sig_hex,
993  rc);
994  goto out;
995  }
996  rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&s->desc.tfm,
997  &s->tfm_mutex,
998  s->cipher_string);
999  if (unlikely(rc)) {
1000  printk(KERN_ERR "Internal error whilst attempting to get "
1001  "tfm and mutex for cipher name [%s]; rc = [%d]\n",
1002  s->cipher_string, rc);
1003  goto out;
1004  }
1005  mutex_lock(s->tfm_mutex);
1006  rc = virt_to_scatterlist(&data[(*packet_size)],
1007  s->block_aligned_filename_size, s->src_sg, 2);
1008  if (rc < 1) {
1009  printk(KERN_ERR "%s: Internal error whilst attempting to "
1010  "convert encrypted filename memory to scatterlist; "
1011  "rc = [%d]. block_aligned_filename_size = [%zd]\n",
1012  __func__, rc, s->block_aligned_filename_size);
1013  goto out_unlock;
1014  }
1015  (*packet_size) += s->block_aligned_filename_size;
1016  s->decrypted_filename = kmalloc(s->block_aligned_filename_size,
1017  GFP_KERNEL);
1018  if (!s->decrypted_filename) {
1019  printk(KERN_ERR "%s: Out of memory whilst attempting to "
1020  "kmalloc [%zd] bytes\n", __func__,
1021  s->block_aligned_filename_size);
1022  rc = -ENOMEM;
1023  goto out_unlock;
1024  }
1025  rc = virt_to_scatterlist(s->decrypted_filename,
1026  s->block_aligned_filename_size, s->dst_sg, 2);
1027  if (rc < 1) {
1028  printk(KERN_ERR "%s: Internal error whilst attempting to "
1029  "convert decrypted filename memory to scatterlist; "
1030  "rc = [%d]. block_aligned_filename_size = [%zd]\n",
1031  __func__, rc, s->block_aligned_filename_size);
1032  goto out_free_unlock;
1033  }
1034  /* The characters in the first block effectively do the job of
1035  * the IV here, so we just use 0's for the IV. Note the
1036  * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES
1037  * >= ECRYPTFS_MAX_IV_BYTES. */
1038  memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES);
1039  s->desc.info = s->iv;
1040  /* TODO: Support other key modules than passphrase for
1041  * filename encryption */
1042  if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) {
1043  rc = -EOPNOTSUPP;
1044  printk(KERN_INFO "%s: Filename encryption only supports "
1045  "password tokens\n", __func__);
1046  goto out_free_unlock;
1047  }
1048  rc = crypto_blkcipher_setkey(
1049  s->desc.tfm,
1050  s->auth_tok->token.password.session_key_encryption_key,
1051  mount_crypt_stat->global_default_fn_cipher_key_bytes);
1052  if (rc < 0) {
1053  printk(KERN_ERR "%s: Error setting key for crypto context; "
1054  "rc = [%d]. s->auth_tok->token.password.session_key_"
1055  "encryption_key = [0x%p]; mount_crypt_stat->"
1056  "global_default_fn_cipher_key_bytes = [%zd]\n", __func__,
1057  rc,
1058  s->auth_tok->token.password.session_key_encryption_key,
1059  mount_crypt_stat->global_default_fn_cipher_key_bytes);
1060  goto out_free_unlock;
1061  }
1062  rc = crypto_blkcipher_decrypt_iv(&s->desc, s->dst_sg, s->src_sg,
1063  s->block_aligned_filename_size);
1064  if (rc) {
1065  printk(KERN_ERR "%s: Error attempting to decrypt filename; "
1066  "rc = [%d]\n", __func__, rc);
1067  goto out_free_unlock;
1068  }
1069  s->i = 0;
1070  while (s->decrypted_filename[s->i] != '\0'
1071  && s->i < s->block_aligned_filename_size)
1072  s->i++;
1073  if (s->i == s->block_aligned_filename_size) {
1074  printk(KERN_WARNING "%s: Invalid tag 70 packet; could not "
1075  "find valid separator between random characters and "
1076  "the filename\n", __func__);
1077  rc = -EINVAL;
1078  goto out_free_unlock;
1079  }
1080  s->i++;
1081  (*filename_size) = (s->block_aligned_filename_size - s->i);
1082  if (!((*filename_size) > 0 && (*filename_size < PATH_MAX))) {
1083  printk(KERN_WARNING "%s: Filename size is [%zd], which is "
1084  "invalid\n", __func__, (*filename_size));
1085  rc = -EINVAL;
1086  goto out_free_unlock;
1087  }
1088  (*filename) = kmalloc(((*filename_size) + 1), GFP_KERNEL);
1089  if (!(*filename)) {
1090  printk(KERN_ERR "%s: Out of memory whilst attempting to "
1091  "kmalloc [%zd] bytes\n", __func__,
1092  ((*filename_size) + 1));
1093  rc = -ENOMEM;
1094  goto out_free_unlock;
1095  }
1096  memcpy((*filename), &s->decrypted_filename[s->i], (*filename_size));
1097  (*filename)[(*filename_size)] = '\0';
1098 out_free_unlock:
1099  kfree(s->decrypted_filename);
1100 out_unlock:
1101  mutex_unlock(s->tfm_mutex);
1102 out:
1103  if (rc) {
1104  (*packet_size) = 0;
1105  (*filename_size) = 0;
1106  (*filename) = NULL;
1107  }
1108  if (auth_tok_key) {
1109  up_write(&(auth_tok_key->sem));
1110  key_put(auth_tok_key);
1111  }
1112  kfree(s);
1113  return rc;
1114 }
1115 
1116 static int
1117 ecryptfs_get_auth_tok_sig(char **sig, struct ecryptfs_auth_tok *auth_tok)
1118 {
1119  int rc = 0;
1120 
1121  (*sig) = NULL;
1122  switch (auth_tok->token_type) {
1123  case ECRYPTFS_PASSWORD:
1124  (*sig) = auth_tok->token.password.signature;
1125  break;
1126  case ECRYPTFS_PRIVATE_KEY:
1127  (*sig) = auth_tok->token.private_key.signature;
1128  break;
1129  default:
1130  printk(KERN_ERR "Cannot get sig for auth_tok of type [%d]\n",
1131  auth_tok->token_type);
1132  rc = -EINVAL;
1133  }
1134  return rc;
1135 }
1136 
1144 static int
1145 decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
1146  struct ecryptfs_crypt_stat *crypt_stat)
1147 {
1148  u8 cipher_code = 0;
1149  struct ecryptfs_msg_ctx *msg_ctx;
1150  struct ecryptfs_message *msg = NULL;
1151  char *auth_tok_sig;
1152  char *payload;
1153  size_t payload_len;
1154  int rc;
1155 
1156  rc = ecryptfs_get_auth_tok_sig(&auth_tok_sig, auth_tok);
1157  if (rc) {
1158  printk(KERN_ERR "Unrecognized auth tok type: [%d]\n",
1159  auth_tok->token_type);
1160  goto out;
1161  }
1162  rc = write_tag_64_packet(auth_tok_sig, &(auth_tok->session_key),
1163  &payload, &payload_len);
1164  if (rc) {
1165  ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet\n");
1166  goto out;
1167  }
1168  rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
1169  if (rc) {
1170  ecryptfs_printk(KERN_ERR, "Error sending message to "
1171  "ecryptfsd\n");
1172  goto out;
1173  }
1174  rc = ecryptfs_wait_for_response(msg_ctx, &msg);
1175  if (rc) {
1176  ecryptfs_printk(KERN_ERR, "Failed to receive tag 65 packet "
1177  "from the user space daemon\n");
1178  rc = -EIO;
1179  goto out;
1180  }
1181  rc = parse_tag_65_packet(&(auth_tok->session_key),
1182  &cipher_code, msg);
1183  if (rc) {
1184  printk(KERN_ERR "Failed to parse tag 65 packet; rc = [%d]\n",
1185  rc);
1186  goto out;
1187  }
1188  auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1189  memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key,
1190  auth_tok->session_key.decrypted_key_size);
1191  crypt_stat->key_size = auth_tok->session_key.decrypted_key_size;
1192  rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher, cipher_code);
1193  if (rc) {
1194  ecryptfs_printk(KERN_ERR, "Cipher code [%d] is invalid\n",
1195  cipher_code)
1196  goto out;
1197  }
1198  crypt_stat->flags |= ECRYPTFS_KEY_VALID;
1199  if (ecryptfs_verbosity > 0) {
1200  ecryptfs_printk(KERN_DEBUG, "Decrypted session key:\n");
1201  ecryptfs_dump_hex(crypt_stat->key,
1202  crypt_stat->key_size);
1203  }
1204 out:
1205  if (msg)
1206  kfree(msg);
1207  return rc;
1208 }
1209 
1210 static void wipe_auth_tok_list(struct list_head *auth_tok_list_head)
1211 {
1212  struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1213  struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
1214 
1215  list_for_each_entry_safe(auth_tok_list_item, auth_tok_list_item_tmp,
1216  auth_tok_list_head, list) {
1217  list_del(&auth_tok_list_item->list);
1218  kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1219  auth_tok_list_item);
1220  }
1221 }
1222 
1223 struct kmem_cache *ecryptfs_auth_tok_list_item_cache;
1224 
1242 static int
1243 parse_tag_1_packet(struct ecryptfs_crypt_stat *crypt_stat,
1244  unsigned char *data, struct list_head *auth_tok_list,
1245  struct ecryptfs_auth_tok **new_auth_tok,
1246  size_t *packet_size, size_t max_packet_size)
1247 {
1248  size_t body_size;
1249  struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1250  size_t length_size;
1251  int rc = 0;
1252 
1253  (*packet_size) = 0;
1254  (*new_auth_tok) = NULL;
1268  if (unlikely(max_packet_size < 12)) {
1269  printk(KERN_ERR "Invalid max packet size; must be >=12\n");
1270  rc = -EINVAL;
1271  goto out;
1272  }
1273  if (data[(*packet_size)++] != ECRYPTFS_TAG_1_PACKET_TYPE) {
1274  printk(KERN_ERR "Enter w/ first byte != 0x%.2x\n",
1275  ECRYPTFS_TAG_1_PACKET_TYPE);
1276  rc = -EINVAL;
1277  goto out;
1278  }
1279  /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
1280  * at end of function upon failure */
1281  auth_tok_list_item =
1282  kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache,
1283  GFP_KERNEL);
1284  if (!auth_tok_list_item) {
1285  printk(KERN_ERR "Unable to allocate memory\n");
1286  rc = -ENOMEM;
1287  goto out;
1288  }
1289  (*new_auth_tok) = &auth_tok_list_item->auth_tok;
1290  rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1291  &length_size);
1292  if (rc) {
1293  printk(KERN_WARNING "Error parsing packet length; "
1294  "rc = [%d]\n", rc);
1295  goto out_free;
1296  }
1297  if (unlikely(body_size < (ECRYPTFS_SIG_SIZE + 2))) {
1298  printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
1299  rc = -EINVAL;
1300  goto out_free;
1301  }
1302  (*packet_size) += length_size;
1303  if (unlikely((*packet_size) + body_size > max_packet_size)) {
1304  printk(KERN_WARNING "Packet size exceeds max\n");
1305  rc = -EINVAL;
1306  goto out_free;
1307  }
1308  if (unlikely(data[(*packet_size)++] != 0x03)) {
1309  printk(KERN_WARNING "Unknown version number [%d]\n",
1310  data[(*packet_size) - 1]);
1311  rc = -EINVAL;
1312  goto out_free;
1313  }
1314  ecryptfs_to_hex((*new_auth_tok)->token.private_key.signature,
1315  &data[(*packet_size)], ECRYPTFS_SIG_SIZE);
1316  *packet_size += ECRYPTFS_SIG_SIZE;
1317  /* This byte is skipped because the kernel does not need to
1318  * know which public key encryption algorithm was used */
1319  (*packet_size)++;
1320  (*new_auth_tok)->session_key.encrypted_key_size =
1321  body_size - (ECRYPTFS_SIG_SIZE + 2);
1322  if ((*new_auth_tok)->session_key.encrypted_key_size
1323  > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
1324  printk(KERN_WARNING "Tag 1 packet contains key larger "
1325  "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES");
1326  rc = -EINVAL;
1327  goto out;
1328  }
1329  memcpy((*new_auth_tok)->session_key.encrypted_key,
1330  &data[(*packet_size)], (body_size - (ECRYPTFS_SIG_SIZE + 2)));
1331  (*packet_size) += (*new_auth_tok)->session_key.encrypted_key_size;
1332  (*new_auth_tok)->session_key.flags &=
1333  ~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1334  (*new_auth_tok)->session_key.flags |=
1335  ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
1336  (*new_auth_tok)->token_type = ECRYPTFS_PRIVATE_KEY;
1337  (*new_auth_tok)->flags = 0;
1338  (*new_auth_tok)->session_key.flags &=
1339  ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
1340  (*new_auth_tok)->session_key.flags &=
1341  ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT);
1342  list_add(&auth_tok_list_item->list, auth_tok_list);
1343  goto out;
1344 out_free:
1345  (*new_auth_tok) = NULL;
1346  memset(auth_tok_list_item, 0,
1347  sizeof(struct ecryptfs_auth_tok_list_item));
1348  kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1349  auth_tok_list_item);
1350 out:
1351  if (rc)
1352  (*packet_size) = 0;
1353  return rc;
1354 }
1355 
1374 static int
1375 parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
1376  unsigned char *data, struct list_head *auth_tok_list,
1377  struct ecryptfs_auth_tok **new_auth_tok,
1378  size_t *packet_size, size_t max_packet_size)
1379 {
1380  size_t body_size;
1381  struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1382  size_t length_size;
1383  int rc = 0;
1384 
1385  (*packet_size) = 0;
1386  (*new_auth_tok) = NULL;
1403  if (max_packet_size < (ECRYPTFS_SALT_SIZE + 7)) {
1404  printk(KERN_ERR "Max packet size too large\n");
1405  rc = -EINVAL;
1406  goto out;
1407  }
1408  if (data[(*packet_size)++] != ECRYPTFS_TAG_3_PACKET_TYPE) {
1409  printk(KERN_ERR "First byte != 0x%.2x; invalid packet\n",
1410  ECRYPTFS_TAG_3_PACKET_TYPE);
1411  rc = -EINVAL;
1412  goto out;
1413  }
1414  /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
1415  * at end of function upon failure */
1416  auth_tok_list_item =
1417  kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, GFP_KERNEL);
1418  if (!auth_tok_list_item) {
1419  printk(KERN_ERR "Unable to allocate memory\n");
1420  rc = -ENOMEM;
1421  goto out;
1422  }
1423  (*new_auth_tok) = &auth_tok_list_item->auth_tok;
1424  rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1425  &length_size);
1426  if (rc) {
1427  printk(KERN_WARNING "Error parsing packet length; rc = [%d]\n",
1428  rc);
1429  goto out_free;
1430  }
1431  if (unlikely(body_size < (ECRYPTFS_SALT_SIZE + 5))) {
1432  printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
1433  rc = -EINVAL;
1434  goto out_free;
1435  }
1436  (*packet_size) += length_size;
1437  if (unlikely((*packet_size) + body_size > max_packet_size)) {
1438  printk(KERN_ERR "Packet size exceeds max\n");
1439  rc = -EINVAL;
1440  goto out_free;
1441  }
1442  (*new_auth_tok)->session_key.encrypted_key_size =
1443  (body_size - (ECRYPTFS_SALT_SIZE + 5));
1444  if ((*new_auth_tok)->session_key.encrypted_key_size
1445  > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
1446  printk(KERN_WARNING "Tag 3 packet contains key larger "
1447  "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES\n");
1448  rc = -EINVAL;
1449  goto out_free;
1450  }
1451  if (unlikely(data[(*packet_size)++] != 0x04)) {
1452  printk(KERN_WARNING "Unknown version number [%d]\n",
1453  data[(*packet_size) - 1]);
1454  rc = -EINVAL;
1455  goto out_free;
1456  }
1457  rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher,
1458  (u16)data[(*packet_size)]);
1459  if (rc)
1460  goto out_free;
1461  /* A little extra work to differentiate among the AES key
1462  * sizes; see RFC2440 */
1463  switch(data[(*packet_size)++]) {
1464  case RFC2440_CIPHER_AES_192:
1465  crypt_stat->key_size = 24;
1466  break;
1467  default:
1468  crypt_stat->key_size =
1469  (*new_auth_tok)->session_key.encrypted_key_size;
1470  }
1471  rc = ecryptfs_init_crypt_ctx(crypt_stat);
1472  if (rc)
1473  goto out_free;
1474  if (unlikely(data[(*packet_size)++] != 0x03)) {
1475  printk(KERN_WARNING "Only S2K ID 3 is currently supported\n");
1476  rc = -ENOSYS;
1477  goto out_free;
1478  }
1479  /* TODO: finish the hash mapping */
1480  switch (data[(*packet_size)++]) {
1481  case 0x01: /* See RFC2440 for these numbers and their mappings */
1482  /* Choose MD5 */
1483  memcpy((*new_auth_tok)->token.password.salt,
1484  &data[(*packet_size)], ECRYPTFS_SALT_SIZE);
1485  (*packet_size) += ECRYPTFS_SALT_SIZE;
1486  /* This conversion was taken straight from RFC2440 */
1487  (*new_auth_tok)->token.password.hash_iterations =
1488  ((u32) 16 + (data[(*packet_size)] & 15))
1489  << ((data[(*packet_size)] >> 4) + 6);
1490  (*packet_size)++;
1491  /* Friendly reminder:
1492  * (*new_auth_tok)->session_key.encrypted_key_size =
1493  * (body_size - (ECRYPTFS_SALT_SIZE + 5)); */
1494  memcpy((*new_auth_tok)->session_key.encrypted_key,
1495  &data[(*packet_size)],
1496  (*new_auth_tok)->session_key.encrypted_key_size);
1497  (*packet_size) +=
1498  (*new_auth_tok)->session_key.encrypted_key_size;
1499  (*new_auth_tok)->session_key.flags &=
1500  ~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1501  (*new_auth_tok)->session_key.flags |=
1502  ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
1503  (*new_auth_tok)->token.password.hash_algo = 0x01; /* MD5 */
1504  break;
1505  default:
1506  ecryptfs_printk(KERN_ERR, "Unsupported hash algorithm: "
1507  "[%d]\n", data[(*packet_size) - 1]);
1508  rc = -ENOSYS;
1509  goto out_free;
1510  }
1511  (*new_auth_tok)->token_type = ECRYPTFS_PASSWORD;
1512  /* TODO: Parametarize; we might actually want userspace to
1513  * decrypt the session key. */
1514  (*new_auth_tok)->session_key.flags &=
1515  ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
1516  (*new_auth_tok)->session_key.flags &=
1517  ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT);
1518  list_add(&auth_tok_list_item->list, auth_tok_list);
1519  goto out;
1520 out_free:
1521  (*new_auth_tok) = NULL;
1522  memset(auth_tok_list_item, 0,
1523  sizeof(struct ecryptfs_auth_tok_list_item));
1524  kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1525  auth_tok_list_item);
1526 out:
1527  if (rc)
1528  (*packet_size) = 0;
1529  return rc;
1530 }
1531 
1548 static int
1549 parse_tag_11_packet(unsigned char *data, unsigned char *contents,
1550  size_t max_contents_bytes, size_t *tag_11_contents_size,
1551  size_t *packet_size, size_t max_packet_size)
1552 {
1553  size_t body_size;
1554  size_t length_size;
1555  int rc = 0;
1556 
1557  (*packet_size) = 0;
1558  (*tag_11_contents_size) = 0;
1559  /* This format is inspired by OpenPGP; see RFC 2440
1560  * packet tag 11
1561  *
1562  * Tag 11 identifier (1 byte)
1563  * Max Tag 11 packet size (max 3 bytes)
1564  * Binary format specifier (1 byte)
1565  * Filename length (1 byte)
1566  * Filename ("_CONSOLE") (8 bytes)
1567  * Modification date (4 bytes)
1568  * Literal data (arbitrary)
1569  *
1570  * We need at least 16 bytes of data for the packet to even be
1571  * valid.
1572  */
1573  if (max_packet_size < 16) {
1574  printk(KERN_ERR "Maximum packet size too small\n");
1575  rc = -EINVAL;
1576  goto out;
1577  }
1578  if (data[(*packet_size)++] != ECRYPTFS_TAG_11_PACKET_TYPE) {
1579  printk(KERN_WARNING "Invalid tag 11 packet format\n");
1580  rc = -EINVAL;
1581  goto out;
1582  }
1583  rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1584  &length_size);
1585  if (rc) {
1586  printk(KERN_WARNING "Invalid tag 11 packet format\n");
1587  goto out;
1588  }
1589  if (body_size < 14) {
1590  printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
1591  rc = -EINVAL;
1592  goto out;
1593  }
1594  (*packet_size) += length_size;
1595  (*tag_11_contents_size) = (body_size - 14);
1596  if (unlikely((*packet_size) + body_size + 1 > max_packet_size)) {
1597  printk(KERN_ERR "Packet size exceeds max\n");
1598  rc = -EINVAL;
1599  goto out;
1600  }
1601  if (unlikely((*tag_11_contents_size) > max_contents_bytes)) {
1602  printk(KERN_ERR "Literal data section in tag 11 packet exceeds "
1603  "expected size\n");
1604  rc = -EINVAL;
1605  goto out;
1606  }
1607  if (data[(*packet_size)++] != 0x62) {
1608  printk(KERN_WARNING "Unrecognizable packet\n");
1609  rc = -EINVAL;
1610  goto out;
1611  }
1612  if (data[(*packet_size)++] != 0x08) {
1613  printk(KERN_WARNING "Unrecognizable packet\n");
1614  rc = -EINVAL;
1615  goto out;
1616  }
1617  (*packet_size) += 12; /* Ignore filename and modification date */
1618  memcpy(contents, &data[(*packet_size)], (*tag_11_contents_size));
1619  (*packet_size) += (*tag_11_contents_size);
1620 out:
1621  if (rc) {
1622  (*packet_size) = 0;
1623  (*tag_11_contents_size) = 0;
1624  }
1625  return rc;
1626 }
1627 
1628 int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
1629  struct ecryptfs_auth_tok **auth_tok,
1630  char *sig)
1631 {
1632  int rc = 0;
1633 
1634  (*auth_tok_key) = request_key(&key_type_user, sig, NULL);
1635  if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) {
1636  (*auth_tok_key) = ecryptfs_get_encrypted_key(sig);
1637  if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) {
1638  printk(KERN_ERR "Could not find key with description: [%s]\n",
1639  sig);
1640  rc = process_request_key_err(PTR_ERR(*auth_tok_key));
1641  (*auth_tok_key) = NULL;
1642  goto out;
1643  }
1644  }
1645  down_write(&(*auth_tok_key)->sem);
1646  rc = ecryptfs_verify_auth_tok_from_key(*auth_tok_key, auth_tok);
1647  if (rc) {
1648  up_write(&(*auth_tok_key)->sem);
1649  key_put(*auth_tok_key);
1650  (*auth_tok_key) = NULL;
1651  goto out;
1652  }
1653 out:
1654  return rc;
1655 }
1656 
1664 static int
1665 decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
1666  struct ecryptfs_crypt_stat *crypt_stat)
1667 {
1668  struct scatterlist dst_sg[2];
1669  struct scatterlist src_sg[2];
1670  struct mutex *tfm_mutex;
1671  struct blkcipher_desc desc = {
1672  .flags = CRYPTO_TFM_REQ_MAY_SLEEP
1673  };
1674  int rc = 0;
1675 
1676  if (unlikely(ecryptfs_verbosity > 0)) {
1677  ecryptfs_printk(
1678  KERN_DEBUG, "Session key encryption key (size [%d]):\n",
1679  auth_tok->token.password.session_key_encryption_key_bytes);
1680  ecryptfs_dump_hex(
1681  auth_tok->token.password.session_key_encryption_key,
1682  auth_tok->token.password.session_key_encryption_key_bytes);
1683  }
1684  rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
1685  crypt_stat->cipher);
1686  if (unlikely(rc)) {
1687  printk(KERN_ERR "Internal error whilst attempting to get "
1688  "tfm and mutex for cipher name [%s]; rc = [%d]\n",
1689  crypt_stat->cipher, rc);
1690  goto out;
1691  }
1692  rc = virt_to_scatterlist(auth_tok->session_key.encrypted_key,
1693  auth_tok->session_key.encrypted_key_size,
1694  src_sg, 2);
1695  if (rc < 1 || rc > 2) {
1696  printk(KERN_ERR "Internal error whilst attempting to convert "
1697  "auth_tok->session_key.encrypted_key to scatterlist; "
1698  "expected rc = 1; got rc = [%d]. "
1699  "auth_tok->session_key.encrypted_key_size = [%d]\n", rc,
1700  auth_tok->session_key.encrypted_key_size);
1701  goto out;
1702  }
1703  auth_tok->session_key.decrypted_key_size =
1704  auth_tok->session_key.encrypted_key_size;
1705  rc = virt_to_scatterlist(auth_tok->session_key.decrypted_key,
1706  auth_tok->session_key.decrypted_key_size,
1707  dst_sg, 2);
1708  if (rc < 1 || rc > 2) {
1709  printk(KERN_ERR "Internal error whilst attempting to convert "
1710  "auth_tok->session_key.decrypted_key to scatterlist; "
1711  "expected rc = 1; got rc = [%d]\n", rc);
1712  goto out;
1713  }
1714  mutex_lock(tfm_mutex);
1715  rc = crypto_blkcipher_setkey(
1716  desc.tfm, auth_tok->token.password.session_key_encryption_key,
1717  crypt_stat->key_size);
1718  if (unlikely(rc < 0)) {
1719  mutex_unlock(tfm_mutex);
1720  printk(KERN_ERR "Error setting key for crypto context\n");
1721  rc = -EINVAL;
1722  goto out;
1723  }
1724  rc = crypto_blkcipher_decrypt(&desc, dst_sg, src_sg,
1725  auth_tok->session_key.encrypted_key_size);
1726  mutex_unlock(tfm_mutex);
1727  if (unlikely(rc)) {
1728  printk(KERN_ERR "Error decrypting; rc = [%d]\n", rc);
1729  goto out;
1730  }
1731  auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1732  memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key,
1733  auth_tok->session_key.decrypted_key_size);
1734  crypt_stat->flags |= ECRYPTFS_KEY_VALID;
1735  if (unlikely(ecryptfs_verbosity > 0)) {
1736  ecryptfs_printk(KERN_DEBUG, "FEK of size [%zd]:\n",
1737  crypt_stat->key_size);
1738  ecryptfs_dump_hex(crypt_stat->key,
1739  crypt_stat->key_size);
1740  }
1741 out:
1742  return rc;
1743 }
1744 
1758 int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
1759  unsigned char *src,
1760  struct dentry *ecryptfs_dentry)
1761 {
1762  size_t i = 0;
1763  size_t found_auth_tok;
1764  size_t next_packet_is_auth_tok_packet;
1765  struct list_head auth_tok_list;
1766  struct ecryptfs_auth_tok *matching_auth_tok;
1767  struct ecryptfs_auth_tok *candidate_auth_tok;
1768  char *candidate_auth_tok_sig;
1769  size_t packet_size;
1770  struct ecryptfs_auth_tok *new_auth_tok;
1771  unsigned char sig_tmp_space[ECRYPTFS_SIG_SIZE];
1772  struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1773  size_t tag_11_contents_size;
1774  size_t tag_11_packet_size;
1775  struct key *auth_tok_key = NULL;
1776  int rc = 0;
1777 
1778  INIT_LIST_HEAD(&auth_tok_list);
1779  /* Parse the header to find as many packets as we can; these will be
1780  * added the our &auth_tok_list */
1781  next_packet_is_auth_tok_packet = 1;
1782  while (next_packet_is_auth_tok_packet) {
1783  size_t max_packet_size = ((PAGE_CACHE_SIZE - 8) - i);
1784 
1785  switch (src[i]) {
1786  case ECRYPTFS_TAG_3_PACKET_TYPE:
1787  rc = parse_tag_3_packet(crypt_stat,
1788  (unsigned char *)&src[i],
1789  &auth_tok_list, &new_auth_tok,
1790  &packet_size, max_packet_size);
1791  if (rc) {
1792  ecryptfs_printk(KERN_ERR, "Error parsing "
1793  "tag 3 packet\n");
1794  rc = -EIO;
1795  goto out_wipe_list;
1796  }
1797  i += packet_size;
1798  rc = parse_tag_11_packet((unsigned char *)&src[i],
1799  sig_tmp_space,
1800  ECRYPTFS_SIG_SIZE,
1801  &tag_11_contents_size,
1802  &tag_11_packet_size,
1803  max_packet_size);
1804  if (rc) {
1805  ecryptfs_printk(KERN_ERR, "No valid "
1806  "(ecryptfs-specific) literal "
1807  "packet containing "
1808  "authentication token "
1809  "signature found after "
1810  "tag 3 packet\n");
1811  rc = -EIO;
1812  goto out_wipe_list;
1813  }
1814  i += tag_11_packet_size;
1815  if (ECRYPTFS_SIG_SIZE != tag_11_contents_size) {
1816  ecryptfs_printk(KERN_ERR, "Expected "
1817  "signature of size [%d]; "
1818  "read size [%zd]\n",
1819  ECRYPTFS_SIG_SIZE,
1820  tag_11_contents_size);
1821  rc = -EIO;
1822  goto out_wipe_list;
1823  }
1824  ecryptfs_to_hex(new_auth_tok->token.password.signature,
1825  sig_tmp_space, tag_11_contents_size);
1826  new_auth_tok->token.password.signature[
1827  ECRYPTFS_PASSWORD_SIG_SIZE] = '\0';
1828  crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
1829  break;
1830  case ECRYPTFS_TAG_1_PACKET_TYPE:
1831  rc = parse_tag_1_packet(crypt_stat,
1832  (unsigned char *)&src[i],
1833  &auth_tok_list, &new_auth_tok,
1834  &packet_size, max_packet_size);
1835  if (rc) {
1836  ecryptfs_printk(KERN_ERR, "Error parsing "
1837  "tag 1 packet\n");
1838  rc = -EIO;
1839  goto out_wipe_list;
1840  }
1841  i += packet_size;
1842  crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
1843  break;
1844  case ECRYPTFS_TAG_11_PACKET_TYPE:
1845  ecryptfs_printk(KERN_WARNING, "Invalid packet set "
1846  "(Tag 11 not allowed by itself)\n");
1847  rc = -EIO;
1848  goto out_wipe_list;
1849  break;
1850  default:
1851  ecryptfs_printk(KERN_DEBUG, "No packet at offset [%zd] "
1852  "of the file header; hex value of "
1853  "character is [0x%.2x]\n", i, src[i]);
1854  next_packet_is_auth_tok_packet = 0;
1855  }
1856  }
1857  if (list_empty(&auth_tok_list)) {
1858  printk(KERN_ERR "The lower file appears to be a non-encrypted "
1859  "eCryptfs file; this is not supported in this version "
1860  "of the eCryptfs kernel module\n");
1861  rc = -EINVAL;
1862  goto out;
1863  }
1864  /* auth_tok_list contains the set of authentication tokens
1865  * parsed from the metadata. We need to find a matching
1866  * authentication token that has the secret component(s)
1867  * necessary to decrypt the EFEK in the auth_tok parsed from
1868  * the metadata. There may be several potential matches, but
1869  * just one will be sufficient to decrypt to get the FEK. */
1870 find_next_matching_auth_tok:
1871  found_auth_tok = 0;
1872  list_for_each_entry(auth_tok_list_item, &auth_tok_list, list) {
1873  candidate_auth_tok = &auth_tok_list_item->auth_tok;
1874  if (unlikely(ecryptfs_verbosity > 0)) {
1875  ecryptfs_printk(KERN_DEBUG,
1876  "Considering cadidate auth tok:\n");
1877  ecryptfs_dump_auth_tok(candidate_auth_tok);
1878  }
1879  rc = ecryptfs_get_auth_tok_sig(&candidate_auth_tok_sig,
1880  candidate_auth_tok);
1881  if (rc) {
1882  printk(KERN_ERR
1883  "Unrecognized candidate auth tok type: [%d]\n",
1884  candidate_auth_tok->token_type);
1885  rc = -EINVAL;
1886  goto out_wipe_list;
1887  }
1888  rc = ecryptfs_find_auth_tok_for_sig(&auth_tok_key,
1889  &matching_auth_tok,
1890  crypt_stat->mount_crypt_stat,
1891  candidate_auth_tok_sig);
1892  if (!rc) {
1893  found_auth_tok = 1;
1894  goto found_matching_auth_tok;
1895  }
1896  }
1897  if (!found_auth_tok) {
1898  ecryptfs_printk(KERN_ERR, "Could not find a usable "
1899  "authentication token\n");
1900  rc = -EIO;
1901  goto out_wipe_list;
1902  }
1903 found_matching_auth_tok:
1904  if (candidate_auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
1905  memcpy(&(candidate_auth_tok->token.private_key),
1906  &(matching_auth_tok->token.private_key),
1907  sizeof(struct ecryptfs_private_key));
1908  up_write(&(auth_tok_key->sem));
1909  key_put(auth_tok_key);
1910  rc = decrypt_pki_encrypted_session_key(candidate_auth_tok,
1911  crypt_stat);
1912  } else if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD) {
1913  memcpy(&(candidate_auth_tok->token.password),
1914  &(matching_auth_tok->token.password),
1915  sizeof(struct ecryptfs_password));
1916  up_write(&(auth_tok_key->sem));
1917  key_put(auth_tok_key);
1918  rc = decrypt_passphrase_encrypted_session_key(
1919  candidate_auth_tok, crypt_stat);
1920  } else {
1921  up_write(&(auth_tok_key->sem));
1922  key_put(auth_tok_key);
1923  rc = -EINVAL;
1924  }
1925  if (rc) {
1926  struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
1927 
1928  ecryptfs_printk(KERN_WARNING, "Error decrypting the "
1929  "session key for authentication token with sig "
1930  "[%.*s]; rc = [%d]. Removing auth tok "
1931  "candidate from the list and searching for "
1932  "the next match.\n", ECRYPTFS_SIG_SIZE_HEX,
1933  candidate_auth_tok_sig, rc);
1934  list_for_each_entry_safe(auth_tok_list_item,
1935  auth_tok_list_item_tmp,
1936  &auth_tok_list, list) {
1937  if (candidate_auth_tok
1938  == &auth_tok_list_item->auth_tok) {
1939  list_del(&auth_tok_list_item->list);
1940  kmem_cache_free(
1941  ecryptfs_auth_tok_list_item_cache,
1942  auth_tok_list_item);
1943  goto find_next_matching_auth_tok;
1944  }
1945  }
1946  BUG();
1947  }
1948  rc = ecryptfs_compute_root_iv(crypt_stat);
1949  if (rc) {
1950  ecryptfs_printk(KERN_ERR, "Error computing "
1951  "the root IV\n");
1952  goto out_wipe_list;
1953  }
1954  rc = ecryptfs_init_crypt_ctx(crypt_stat);
1955  if (rc) {
1956  ecryptfs_printk(KERN_ERR, "Error initializing crypto "
1957  "context for cipher [%s]; rc = [%d]\n",
1958  crypt_stat->cipher, rc);
1959  }
1960 out_wipe_list:
1961  wipe_auth_tok_list(&auth_tok_list);
1962 out:
1963  return rc;
1964 }
1965 
1966 static int
1967 pki_encrypt_session_key(struct key *auth_tok_key,
1968  struct ecryptfs_auth_tok *auth_tok,
1969  struct ecryptfs_crypt_stat *crypt_stat,
1970  struct ecryptfs_key_record *key_rec)
1971 {
1972  struct ecryptfs_msg_ctx *msg_ctx = NULL;
1973  char *payload = NULL;
1974  size_t payload_len = 0;
1975  struct ecryptfs_message *msg;
1976  int rc;
1977 
1978  rc = write_tag_66_packet(auth_tok->token.private_key.signature,
1979  ecryptfs_code_for_cipher_string(
1980  crypt_stat->cipher,
1981  crypt_stat->key_size),
1982  crypt_stat, &payload, &payload_len);
1983  up_write(&(auth_tok_key->sem));
1984  key_put(auth_tok_key);
1985  if (rc) {
1986  ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet\n");
1987  goto out;
1988  }
1989  rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
1990  if (rc) {
1991  ecryptfs_printk(KERN_ERR, "Error sending message to "
1992  "ecryptfsd\n");
1993  goto out;
1994  }
1995  rc = ecryptfs_wait_for_response(msg_ctx, &msg);
1996  if (rc) {
1997  ecryptfs_printk(KERN_ERR, "Failed to receive tag 67 packet "
1998  "from the user space daemon\n");
1999  rc = -EIO;
2000  goto out;
2001  }
2002  rc = parse_tag_67_packet(key_rec, msg);
2003  if (rc)
2004  ecryptfs_printk(KERN_ERR, "Error parsing tag 67 packet\n");
2005  kfree(msg);
2006 out:
2007  kfree(payload);
2008  return rc;
2009 }
2024 static int
2025 write_tag_1_packet(char *dest, size_t *remaining_bytes,
2026  struct key *auth_tok_key, struct ecryptfs_auth_tok *auth_tok,
2027  struct ecryptfs_crypt_stat *crypt_stat,
2028  struct ecryptfs_key_record *key_rec, size_t *packet_size)
2029 {
2030  size_t i;
2031  size_t encrypted_session_key_valid = 0;
2032  size_t packet_size_length;
2033  size_t max_packet_size;
2034  int rc = 0;
2035 
2036  (*packet_size) = 0;
2037  ecryptfs_from_hex(key_rec->sig, auth_tok->token.private_key.signature,
2038  ECRYPTFS_SIG_SIZE);
2039  encrypted_session_key_valid = 0;
2040  for (i = 0; i < crypt_stat->key_size; i++)
2041  encrypted_session_key_valid |=
2042  auth_tok->session_key.encrypted_key[i];
2043  if (encrypted_session_key_valid) {
2044  memcpy(key_rec->enc_key,
2045  auth_tok->session_key.encrypted_key,
2046  auth_tok->session_key.encrypted_key_size);
2047  up_write(&(auth_tok_key->sem));
2048  key_put(auth_tok_key);
2049  goto encrypted_session_key_set;
2050  }
2051  if (auth_tok->session_key.encrypted_key_size == 0)
2052  auth_tok->session_key.encrypted_key_size =
2053  auth_tok->token.private_key.key_size;
2054  rc = pki_encrypt_session_key(auth_tok_key, auth_tok, crypt_stat,
2055  key_rec);
2056  if (rc) {
2057  printk(KERN_ERR "Failed to encrypt session key via a key "
2058  "module; rc = [%d]\n", rc);
2059  goto out;
2060  }
2061  if (ecryptfs_verbosity > 0) {
2062  ecryptfs_printk(KERN_DEBUG, "Encrypted key:\n");
2063  ecryptfs_dump_hex(key_rec->enc_key, key_rec->enc_key_size);
2064  }
2065 encrypted_session_key_set:
2066  /* This format is inspired by OpenPGP; see RFC 2440
2067  * packet tag 1 */
2068  max_packet_size = (1 /* Tag 1 identifier */
2069  + 3 /* Max Tag 1 packet size */
2070  + 1 /* Version */
2071  + ECRYPTFS_SIG_SIZE /* Key identifier */
2072  + 1 /* Cipher identifier */
2073  + key_rec->enc_key_size); /* Encrypted key size */
2074  if (max_packet_size > (*remaining_bytes)) {
2075  printk(KERN_ERR "Packet length larger than maximum allowable; "
2076  "need up to [%td] bytes, but there are only [%td] "
2077  "available\n", max_packet_size, (*remaining_bytes));
2078  rc = -EINVAL;
2079  goto out;
2080  }
2081  dest[(*packet_size)++] = ECRYPTFS_TAG_1_PACKET_TYPE;
2082  rc = ecryptfs_write_packet_length(&dest[(*packet_size)],
2083  (max_packet_size - 4),
2084  &packet_size_length);
2085  if (rc) {
2086  ecryptfs_printk(KERN_ERR, "Error generating tag 1 packet "
2087  "header; cannot generate packet length\n");
2088  goto out;
2089  }
2090  (*packet_size) += packet_size_length;
2091  dest[(*packet_size)++] = 0x03; /* version 3 */
2092  memcpy(&dest[(*packet_size)], key_rec->sig, ECRYPTFS_SIG_SIZE);
2093  (*packet_size) += ECRYPTFS_SIG_SIZE;
2094  dest[(*packet_size)++] = RFC2440_CIPHER_RSA;
2095  memcpy(&dest[(*packet_size)], key_rec->enc_key,
2096  key_rec->enc_key_size);
2097  (*packet_size) += key_rec->enc_key_size;
2098 out:
2099  if (rc)
2100  (*packet_size) = 0;
2101  else
2102  (*remaining_bytes) -= (*packet_size);
2103  return rc;
2104 }
2105 
2116 static int
2117 write_tag_11_packet(char *dest, size_t *remaining_bytes, char *contents,
2118  size_t contents_length, size_t *packet_length)
2119 {
2120  size_t packet_size_length;
2121  size_t max_packet_size;
2122  int rc = 0;
2123 
2124  (*packet_length) = 0;
2125  /* This format is inspired by OpenPGP; see RFC 2440
2126  * packet tag 11 */
2127  max_packet_size = (1 /* Tag 11 identifier */
2128  + 3 /* Max Tag 11 packet size */
2129  + 1 /* Binary format specifier */
2130  + 1 /* Filename length */
2131  + 8 /* Filename ("_CONSOLE") */
2132  + 4 /* Modification date */
2133  + contents_length); /* Literal data */
2134  if (max_packet_size > (*remaining_bytes)) {
2135  printk(KERN_ERR "Packet length larger than maximum allowable; "
2136  "need up to [%td] bytes, but there are only [%td] "
2137  "available\n", max_packet_size, (*remaining_bytes));
2138  rc = -EINVAL;
2139  goto out;
2140  }
2141  dest[(*packet_length)++] = ECRYPTFS_TAG_11_PACKET_TYPE;
2142  rc = ecryptfs_write_packet_length(&dest[(*packet_length)],
2143  (max_packet_size - 4),
2144  &packet_size_length);
2145  if (rc) {
2146  printk(KERN_ERR "Error generating tag 11 packet header; cannot "
2147  "generate packet length. rc = [%d]\n", rc);
2148  goto out;
2149  }
2150  (*packet_length) += packet_size_length;
2151  dest[(*packet_length)++] = 0x62; /* binary data format specifier */
2152  dest[(*packet_length)++] = 8;
2153  memcpy(&dest[(*packet_length)], "_CONSOLE", 8);
2154  (*packet_length) += 8;
2155  memset(&dest[(*packet_length)], 0x00, 4);
2156  (*packet_length) += 4;
2157  memcpy(&dest[(*packet_length)], contents, contents_length);
2158  (*packet_length) += contents_length;
2159  out:
2160  if (rc)
2161  (*packet_length) = 0;
2162  else
2163  (*remaining_bytes) -= (*packet_length);
2164  return rc;
2165 }
2166 
2179 static int
2180 write_tag_3_packet(char *dest, size_t *remaining_bytes,
2181  struct ecryptfs_auth_tok *auth_tok,
2182  struct ecryptfs_crypt_stat *crypt_stat,
2183  struct ecryptfs_key_record *key_rec, size_t *packet_size)
2184 {
2185  size_t i;
2186  size_t encrypted_session_key_valid = 0;
2187  char session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES];
2188  struct scatterlist dst_sg[2];
2189  struct scatterlist src_sg[2];
2190  struct mutex *tfm_mutex = NULL;
2191  u8 cipher_code;
2192  size_t packet_size_length;
2193  size_t max_packet_size;
2194  struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
2195  crypt_stat->mount_crypt_stat;
2196  struct blkcipher_desc desc = {
2197  .tfm = NULL,
2198  .flags = CRYPTO_TFM_REQ_MAY_SLEEP
2199  };
2200  int rc = 0;
2201 
2202  (*packet_size) = 0;
2203  ecryptfs_from_hex(key_rec->sig, auth_tok->token.password.signature,
2204  ECRYPTFS_SIG_SIZE);
2205  rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
2206  crypt_stat->cipher);
2207  if (unlikely(rc)) {
2208  printk(KERN_ERR "Internal error whilst attempting to get "
2209  "tfm and mutex for cipher name [%s]; rc = [%d]\n",
2210  crypt_stat->cipher, rc);
2211  goto out;
2212  }
2213  if (mount_crypt_stat->global_default_cipher_key_size == 0) {
2214  struct blkcipher_alg *alg = crypto_blkcipher_alg(desc.tfm);
2215 
2216  printk(KERN_WARNING "No key size specified at mount; "
2217  "defaulting to [%d]\n", alg->max_keysize);
2218  mount_crypt_stat->global_default_cipher_key_size =
2219  alg->max_keysize;
2220  }
2221  if (crypt_stat->key_size == 0)
2222  crypt_stat->key_size =
2223  mount_crypt_stat->global_default_cipher_key_size;
2224  if (auth_tok->session_key.encrypted_key_size == 0)
2225  auth_tok->session_key.encrypted_key_size =
2226  crypt_stat->key_size;
2227  if (crypt_stat->key_size == 24
2228  && strcmp("aes", crypt_stat->cipher) == 0) {
2229  memset((crypt_stat->key + 24), 0, 8);
2230  auth_tok->session_key.encrypted_key_size = 32;
2231  } else
2232  auth_tok->session_key.encrypted_key_size = crypt_stat->key_size;
2233  key_rec->enc_key_size =
2234  auth_tok->session_key.encrypted_key_size;
2235  encrypted_session_key_valid = 0;
2236  for (i = 0; i < auth_tok->session_key.encrypted_key_size; i++)
2237  encrypted_session_key_valid |=
2238  auth_tok->session_key.encrypted_key[i];
2239  if (encrypted_session_key_valid) {
2240  ecryptfs_printk(KERN_DEBUG, "encrypted_session_key_valid != 0; "
2241  "using auth_tok->session_key.encrypted_key, "
2242  "where key_rec->enc_key_size = [%zd]\n",
2243  key_rec->enc_key_size);
2244  memcpy(key_rec->enc_key,
2245  auth_tok->session_key.encrypted_key,
2246  key_rec->enc_key_size);
2247  goto encrypted_session_key_set;
2248  }
2249  if (auth_tok->token.password.flags &
2250  ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET) {
2251  ecryptfs_printk(KERN_DEBUG, "Using previously generated "
2252  "session key encryption key of size [%d]\n",
2253  auth_tok->token.password.
2254  session_key_encryption_key_bytes);
2255  memcpy(session_key_encryption_key,
2256  auth_tok->token.password.session_key_encryption_key,
2257  crypt_stat->key_size);
2258  ecryptfs_printk(KERN_DEBUG,
2259  "Cached session key encryption key:\n");
2260  if (ecryptfs_verbosity > 0)
2261  ecryptfs_dump_hex(session_key_encryption_key, 16);
2262  }
2263  if (unlikely(ecryptfs_verbosity > 0)) {
2264  ecryptfs_printk(KERN_DEBUG, "Session key encryption key:\n");
2265  ecryptfs_dump_hex(session_key_encryption_key, 16);
2266  }
2267  rc = virt_to_scatterlist(crypt_stat->key, key_rec->enc_key_size,
2268  src_sg, 2);
2269  if (rc < 1 || rc > 2) {
2270  ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
2271  "for crypt_stat session key; expected rc = 1; "
2272  "got rc = [%d]. key_rec->enc_key_size = [%zd]\n",
2273  rc, key_rec->enc_key_size);
2274  rc = -ENOMEM;
2275  goto out;
2276  }
2277  rc = virt_to_scatterlist(key_rec->enc_key, key_rec->enc_key_size,
2278  dst_sg, 2);
2279  if (rc < 1 || rc > 2) {
2280  ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
2281  "for crypt_stat encrypted session key; "
2282  "expected rc = 1; got rc = [%d]. "
2283  "key_rec->enc_key_size = [%zd]\n", rc,
2284  key_rec->enc_key_size);
2285  rc = -ENOMEM;
2286  goto out;
2287  }
2288  mutex_lock(tfm_mutex);
2289  rc = crypto_blkcipher_setkey(desc.tfm, session_key_encryption_key,
2290  crypt_stat->key_size);
2291  if (rc < 0) {
2292  mutex_unlock(tfm_mutex);
2293  ecryptfs_printk(KERN_ERR, "Error setting key for crypto "
2294  "context; rc = [%d]\n", rc);
2295  goto out;
2296  }
2297  rc = 0;
2298  ecryptfs_printk(KERN_DEBUG, "Encrypting [%zd] bytes of the key\n",
2299  crypt_stat->key_size);
2300  rc = crypto_blkcipher_encrypt(&desc, dst_sg, src_sg,
2301  (*key_rec).enc_key_size);
2302  mutex_unlock(tfm_mutex);
2303  if (rc) {
2304  printk(KERN_ERR "Error encrypting; rc = [%d]\n", rc);
2305  goto out;
2306  }
2307  ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n");
2308  if (ecryptfs_verbosity > 0) {
2309  ecryptfs_printk(KERN_DEBUG, "EFEK of size [%zd]:\n",
2310  key_rec->enc_key_size);
2311  ecryptfs_dump_hex(key_rec->enc_key,
2312  key_rec->enc_key_size);
2313  }
2314 encrypted_session_key_set:
2315  /* This format is inspired by OpenPGP; see RFC 2440
2316  * packet tag 3 */
2317  max_packet_size = (1 /* Tag 3 identifier */
2318  + 3 /* Max Tag 3 packet size */
2319  + 1 /* Version */
2320  + 1 /* Cipher code */
2321  + 1 /* S2K specifier */
2322  + 1 /* Hash identifier */
2323  + ECRYPTFS_SALT_SIZE /* Salt */
2324  + 1 /* Hash iterations */
2325  + key_rec->enc_key_size); /* Encrypted key size */
2326  if (max_packet_size > (*remaining_bytes)) {
2327  printk(KERN_ERR "Packet too large; need up to [%td] bytes, but "
2328  "there are only [%td] available\n", max_packet_size,
2329  (*remaining_bytes));
2330  rc = -EINVAL;
2331  goto out;
2332  }
2333  dest[(*packet_size)++] = ECRYPTFS_TAG_3_PACKET_TYPE;
2334  /* Chop off the Tag 3 identifier(1) and Tag 3 packet size(3)
2335  * to get the number of octets in the actual Tag 3 packet */
2336  rc = ecryptfs_write_packet_length(&dest[(*packet_size)],
2337  (max_packet_size - 4),
2338  &packet_size_length);
2339  if (rc) {
2340  printk(KERN_ERR "Error generating tag 3 packet header; cannot "
2341  "generate packet length. rc = [%d]\n", rc);
2342  goto out;
2343  }
2344  (*packet_size) += packet_size_length;
2345  dest[(*packet_size)++] = 0x04; /* version 4 */
2346  /* TODO: Break from RFC2440 so that arbitrary ciphers can be
2347  * specified with strings */
2348  cipher_code = ecryptfs_code_for_cipher_string(crypt_stat->cipher,
2349  crypt_stat->key_size);
2350  if (cipher_code == 0) {
2351  ecryptfs_printk(KERN_WARNING, "Unable to generate code for "
2352  "cipher [%s]\n", crypt_stat->cipher);
2353  rc = -EINVAL;
2354  goto out;
2355  }
2356  dest[(*packet_size)++] = cipher_code;
2357  dest[(*packet_size)++] = 0x03; /* S2K */
2358  dest[(*packet_size)++] = 0x01; /* MD5 (TODO: parameterize) */
2359  memcpy(&dest[(*packet_size)], auth_tok->token.password.salt,
2360  ECRYPTFS_SALT_SIZE);
2361  (*packet_size) += ECRYPTFS_SALT_SIZE; /* salt */
2362  dest[(*packet_size)++] = 0x60; /* hash iterations (65536) */
2363  memcpy(&dest[(*packet_size)], key_rec->enc_key,
2364  key_rec->enc_key_size);
2365  (*packet_size) += key_rec->enc_key_size;
2366 out:
2367  if (rc)
2368  (*packet_size) = 0;
2369  else
2370  (*remaining_bytes) -= (*packet_size);
2371  return rc;
2372 }
2373 
2374 struct kmem_cache *ecryptfs_key_record_cache;
2375 
2391 int
2392 ecryptfs_generate_key_packet_set(char *dest_base,
2393  struct ecryptfs_crypt_stat *crypt_stat,
2394  struct dentry *ecryptfs_dentry, size_t *len,
2395  size_t max)
2396 {
2397  struct ecryptfs_auth_tok *auth_tok;
2398  struct key *auth_tok_key = NULL;
2399  struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
2400  &ecryptfs_superblock_to_private(
2401  ecryptfs_dentry->d_sb)->mount_crypt_stat;
2402  size_t written;
2403  struct ecryptfs_key_record *key_rec;
2404  struct ecryptfs_key_sig *key_sig;
2405  int rc = 0;
2406 
2407  (*len) = 0;
2408  mutex_lock(&crypt_stat->keysig_list_mutex);
2409  key_rec = kmem_cache_alloc(ecryptfs_key_record_cache, GFP_KERNEL);
2410  if (!key_rec) {
2411  rc = -ENOMEM;
2412  goto out;
2413  }
2414  list_for_each_entry(key_sig, &crypt_stat->keysig_list,
2415  crypt_stat_list) {
2416  memset(key_rec, 0, sizeof(*key_rec));
2417  rc = ecryptfs_find_global_auth_tok_for_sig(&auth_tok_key,
2418  &auth_tok,
2419  mount_crypt_stat,
2420  key_sig->keysig);
2421  if (rc) {
2422  printk(KERN_WARNING "Unable to retrieve auth tok with "
2423  "sig = [%s]\n", key_sig->keysig);
2424  rc = process_find_global_auth_tok_for_sig_err(rc);
2425  goto out_free;
2426  }
2427  if (auth_tok->token_type == ECRYPTFS_PASSWORD) {
2428  rc = write_tag_3_packet((dest_base + (*len)),
2429  &max, auth_tok,
2430  crypt_stat, key_rec,
2431  &written);
2432  up_write(&(auth_tok_key->sem));
2433  key_put(auth_tok_key);
2434  if (rc) {
2435  ecryptfs_printk(KERN_WARNING, "Error "
2436  "writing tag 3 packet\n");
2437  goto out_free;
2438  }
2439  (*len) += written;
2440  /* Write auth tok signature packet */
2441  rc = write_tag_11_packet((dest_base + (*len)), &max,
2442  key_rec->sig,
2443  ECRYPTFS_SIG_SIZE, &written);
2444  if (rc) {
2445  ecryptfs_printk(KERN_ERR, "Error writing "
2446  "auth tok signature packet\n");
2447  goto out_free;
2448  }
2449  (*len) += written;
2450  } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
2451  rc = write_tag_1_packet(dest_base + (*len), &max,
2452  auth_tok_key, auth_tok,
2453  crypt_stat, key_rec, &written);
2454  if (rc) {
2455  ecryptfs_printk(KERN_WARNING, "Error "
2456  "writing tag 1 packet\n");
2457  goto out_free;
2458  }
2459  (*len) += written;
2460  } else {
2461  up_write(&(auth_tok_key->sem));
2462  key_put(auth_tok_key);
2463  ecryptfs_printk(KERN_WARNING, "Unsupported "
2464  "authentication token type\n");
2465  rc = -EINVAL;
2466  goto out_free;
2467  }
2468  }
2469  if (likely(max > 0)) {
2470  dest_base[(*len)] = 0x00;
2471  } else {
2472  ecryptfs_printk(KERN_ERR, "Error writing boundary byte\n");
2473  rc = -EIO;
2474  }
2475 out_free:
2476  kmem_cache_free(ecryptfs_key_record_cache, key_rec);
2477 out:
2478  if (rc)
2479  (*len) = 0;
2480  mutex_unlock(&crypt_stat->keysig_list_mutex);
2481  return rc;
2482 }
2483 
2484 struct kmem_cache *ecryptfs_key_sig_cache;
2485 
2486 int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig)
2487 {
2488  struct ecryptfs_key_sig *new_key_sig;
2489 
2490  new_key_sig = kmem_cache_alloc(ecryptfs_key_sig_cache, GFP_KERNEL);
2491  if (!new_key_sig) {
2492  printk(KERN_ERR
2493  "Error allocating from ecryptfs_key_sig_cache\n");
2494  return -ENOMEM;
2495  }
2496  memcpy(new_key_sig->keysig, sig, ECRYPTFS_SIG_SIZE_HEX);
2497  new_key_sig->keysig[ECRYPTFS_SIG_SIZE_HEX] = '\0';
2498  /* Caller must hold keysig_list_mutex */
2499  list_add(&new_key_sig->crypt_stat_list, &crypt_stat->keysig_list);
2500 
2501  return 0;
2502 }
2503 
2504 struct kmem_cache *ecryptfs_global_auth_tok_cache;
2505 
2506 int
2507 ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
2508  char *sig, u32 global_auth_tok_flags)
2509 {
2510  struct ecryptfs_global_auth_tok *new_auth_tok;
2511  int rc = 0;
2512 
2513  new_auth_tok = kmem_cache_zalloc(ecryptfs_global_auth_tok_cache,
2514  GFP_KERNEL);
2515  if (!new_auth_tok) {
2516  rc = -ENOMEM;
2517  printk(KERN_ERR "Error allocating from "
2518  "ecryptfs_global_auth_tok_cache\n");
2519  goto out;
2520  }
2521  memcpy(new_auth_tok->sig, sig, ECRYPTFS_SIG_SIZE_HEX);
2522  new_auth_tok->flags = global_auth_tok_flags;
2523  new_auth_tok->sig[ECRYPTFS_SIG_SIZE_HEX] = '\0';
2524  mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
2525  list_add(&new_auth_tok->mount_crypt_stat_list,
2526  &mount_crypt_stat->global_auth_tok_list);
2527  mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
2528 out:
2529  return rc;
2530 }
2531 
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