Linux Kernel  3.7.1
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ecryptfs_format.c
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1 /*
2  * ecryptfs_format.c: helper functions for the encrypted key type
3  *
4  * Copyright (C) 2006 International Business Machines Corp.
5  * Copyright (C) 2010 Politecnico di Torino, Italy
6  * TORSEC group -- http://security.polito.it
7  *
8  * Authors:
9  * Michael A. Halcrow <[email protected]>
10  * Tyler Hicks <[email protected]>
11  * Roberto Sassu <[email protected]>
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License as published by
15  * the Free Software Foundation, version 2 of the License.
16  */
17 
18 #include <linux/module.h>
19 #include "ecryptfs_format.h"
20 
22 {
23  return auth_tok->token.password.session_key_encryption_key;
24 }
26 
27 /*
28  * ecryptfs_get_versions()
29  *
30  * Source code taken from the software 'ecryptfs-utils' version 83.
31  *
32  */
33 void ecryptfs_get_versions(int *major, int *minor, int *file_version)
34 {
35  *major = ECRYPTFS_VERSION_MAJOR;
36  *minor = ECRYPTFS_VERSION_MINOR;
37  if (file_version)
38  *file_version = ECRYPTFS_SUPPORTED_FILE_VERSION;
39 }
41 
42 /*
43  * ecryptfs_fill_auth_tok - fill the ecryptfs_auth_tok structure
44  *
45  * Fill the ecryptfs_auth_tok structure with required ecryptfs data.
46  * The source code is inspired to the original function generate_payload()
47  * shipped with the software 'ecryptfs-utils' version 83.
48  *
49  */
51  const char *key_desc)
52 {
53  int major, minor;
54 
55  ecryptfs_get_versions(&major, &minor, NULL);
56  auth_tok->version = (((uint16_t)(major << 8) & 0xFF00)
57  | ((uint16_t)minor & 0x00FF));
58  auth_tok->token_type = ECRYPTFS_PASSWORD;
59  strncpy((char *)auth_tok->token.password.signature, key_desc,
61  auth_tok->token.password.session_key_encryption_key_bytes =
63  /*
64  * Removed auth_tok->token.password.salt and
65  * auth_tok->token.password.session_key_encryption_key
66  * initialization from the original code
67  */
68  /* TODO: Make the hash parameterizable via policy */
69  auth_tok->token.password.flags |=
71  /* The kernel code will encrypt the session key. */
72  auth_tok->session_key.encrypted_key[0] = 0;
73  auth_tok->session_key.encrypted_key_size = 0;
74  /* Default; subject to change by kernel eCryptfs */
75  auth_tok->token.password.hash_algo = PGP_DIGEST_ALGO_SHA512;
76  auth_tok->token.password.flags &= ~(ECRYPTFS_PERSISTENT_PASSWORD);
77  return 0;
78 }
80 
81 MODULE_LICENSE("GPL");