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Member "cryptsetup-2.4.3/lib/volumekey.c" (13 Jan 2022, 3126 Bytes) of package /linux/misc/cryptsetup-2.4.3.tar.xz:


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    1 /*
    2  * cryptsetup volume key implementation
    3  *
    4  * Copyright (C) 2004-2006 Clemens Fruhwirth <clemens@endorphin.org>
    5  * Copyright (C) 2010-2021 Red Hat, Inc. All rights reserved.
    6  *
    7  * This program is free software; you can redistribute it and/or
    8  * modify it under the terms of the GNU General Public License
    9  * as published by the Free Software Foundation; either version 2
   10  * of the License, or (at your option) any later version.
   11  *
   12  * This program is distributed in the hope that it will be useful,
   13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   15  * GNU General Public License for more details.
   16  *
   17  * You should have received a copy of the GNU General Public License
   18  * along with this program; if not, write to the Free Software
   19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
   20  */
   21 
   22 #include <string.h>
   23 #include <stdint.h>
   24 #include <stdlib.h>
   25 #include <errno.h>
   26 
   27 #include "internal.h"
   28 
   29 struct volume_key *crypt_alloc_volume_key(size_t keylength, const char *key)
   30 {
   31     struct volume_key *vk;
   32 
   33     if (keylength > (SIZE_MAX - sizeof(*vk)))
   34         return NULL;
   35 
   36     vk = malloc(sizeof(*vk) + keylength);
   37     if (!vk)
   38         return NULL;
   39 
   40     vk->key_description = NULL;
   41     vk->keylength = keylength;
   42     vk->id = -1;
   43     vk->next = NULL;
   44 
   45     /* keylength 0 is valid => no key */
   46     if (vk->keylength) {
   47         if (key)
   48             memcpy(&vk->key, key, keylength);
   49         else
   50             crypt_safe_memzero(&vk->key, keylength);
   51     }
   52 
   53     return vk;
   54 }
   55 
   56 int crypt_volume_key_set_description(struct volume_key *vk, const char *key_description)
   57 {
   58     if (!vk)
   59         return -EINVAL;
   60 
   61     free(CONST_CAST(void*)vk->key_description);
   62     vk->key_description = NULL;
   63     if (key_description && !(vk->key_description = strdup(key_description)))
   64         return -ENOMEM;
   65 
   66     return 0;
   67 }
   68 
   69 void crypt_volume_key_set_id(struct volume_key *vk, int id)
   70 {
   71     if (vk && id >= 0)
   72         vk->id = id;
   73 }
   74 
   75 int crypt_volume_key_get_id(const struct volume_key *vk)
   76 {
   77     return vk ? vk->id : -1;
   78 }
   79 
   80 struct volume_key *crypt_volume_key_by_id(struct volume_key *vks, int id)
   81 {
   82     struct volume_key *vk = vks;
   83 
   84     if (id < 0)
   85         return NULL;
   86 
   87     while (vk && vk->id != id)
   88         vk = vk->next;
   89 
   90     return vk;
   91 }
   92 
   93 void crypt_volume_key_add_next(struct volume_key **vks, struct volume_key *vk)
   94 {
   95     struct volume_key *tmp;
   96 
   97     if (!vks)
   98         return;
   99 
  100     if (!*vks) {
  101         *vks = vk;
  102         return;
  103     }
  104 
  105     tmp = *vks;
  106 
  107     while (tmp->next)
  108         tmp = tmp->next;
  109 
  110     tmp->next = vk;
  111 }
  112 
  113 struct volume_key *crypt_volume_key_next(struct volume_key *vk)
  114 {
  115     return vk ? vk->next : NULL;
  116 }
  117 
  118 void crypt_free_volume_key(struct volume_key *vk)
  119 {
  120     struct volume_key *vk_next;
  121 
  122     while (vk) {
  123         crypt_safe_memzero(vk->key, vk->keylength);
  124         vk->keylength = 0;
  125         free(CONST_CAST(void*)vk->key_description);
  126         vk_next = vk->next;
  127         free(vk);
  128         vk = vk_next;
  129     }
  130 }
  131 
  132 struct volume_key *crypt_generate_volume_key(struct crypt_device *cd, size_t keylength)
  133 {
  134     int r;
  135     struct volume_key *vk;
  136 
  137     vk = crypt_alloc_volume_key(keylength, NULL);
  138     if (!vk)
  139         return NULL;
  140 
  141     r = crypt_random_get(cd, vk->key, keylength, CRYPT_RND_KEY);
  142     if(r < 0) {
  143         crypt_free_volume_key(vk);
  144         return NULL;
  145     }
  146     return vk;
  147 }