LXR linux/certs/common.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2
   3#include <linux/kernel.h>
   4#include <linux/key.h>
   5#include "common.h"
   6
   7int load_certificate_list(const u8 cert_list[],
   8                          const unsigned long list_size,
   9                          const struct key *keyring)
  10{
  11        key_ref_t key;
  12        const u8 *p, *end;
  13        size_t plen;
  14
  15        p = cert_list;
  16        end = p + list_size;
  17        while (p < end) {
  18                /* Each cert begins with an ASN.1 SEQUENCE tag and must be more
  19                 * than 256 bytes in size.
  20                 */
  21                if (end - p < 4)
  22                        goto dodgy_cert;
  23                if (p[0] != 0x30 &&
  24                    p[1] != 0x82)
  25                        goto dodgy_cert;
  26                plen = (p[2] << 8) | p[3];
  27                plen += 4;
  28                if (plen > end - p)
  29                        goto dodgy_cert;
  30
  31                key = key_create_or_update(make_key_ref(keyring, 1),
  32                                           "asymmetric",
  33                                           NULL,
  34                                           p,
  35                                           plen,
  36                                           ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
  37                                           KEY_USR_VIEW | KEY_USR_READ),
  38                                           KEY_ALLOC_NOT_IN_QUOTA |
  39                                           KEY_ALLOC_BUILT_IN |
  40                                           KEY_ALLOC_BYPASS_RESTRICTION);
  41                if (IS_ERR(key)) {
  42                        pr_err("Problem loading in-kernel X.509 certificate (%ld)\n",
  43                               PTR_ERR(key));
  44                } else {
  45                        pr_notice("Loaded X.509 cert '%s'\n",
  46                                  key_ref_to_ptr(key)->description);
  47                        key_ref_put(key);
  48                }
  49                p += plen;
  50        }
  51
  52        return 0;
  53
  54dodgy_cert:
  55        pr_err("Problem parsing in-kernel X.509 certificate list\n");
  56        return 0;
  57}
  58