src/home/homework-password-cache.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include "homework-password-cache.h"
   4 #include "keyring-util.h"
   5 #include "missing_syscall.h"
   6 #include "user-record.h"
   7
   8 void password_cache_free(PasswordCache *cache) {
   9         if (!cache)
  10                 return;
  11
  12         cache->pkcs11_passwords = strv_free_erase(cache->pkcs11_passwords);
  13         cache->fido2_passwords = strv_free_erase(cache->fido2_passwords);
  14 }
  15
  16 void password_cache_load_keyring(UserRecord *h, PasswordCache *cache) {
  17         _cleanup_(erase_and_freep) void *p = NULL;
  18         _cleanup_free_ char *name = NULL;
  19         char **strv = NULL;
  20         key_serial_t serial;
  21         size_t sz;
  22         int r;
  23
  24         assert(h);
  25         assert(cache);
  26
  27         /* Loads the password we need to for automatic resizing from the kernel keyring */
  28
  29         name = strjoin("homework-user-", h->user_name);
  30         if (!name)
  31                 return (void) log_oom();
  32
  33         serial = request_key("user", name, NULL, 0);
  34         if (serial == -1)
  35                 return (void) log_debug_errno(errno, "Failed to request key '%s', ignoring: %m", name);
  36
  37         r = keyring_read(serial, &p, &sz);
  38         if (r < 0)
  39                 return (void) log_debug_errno(r, "Failed to read keyring key '%s', ignoring: %m", name);
  40
  41         if (memchr(p, 0, sz))
  42                 return (void) log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Cached password contains embedded NUL byte, ignoring.");
  43
  44         strv = new(char*, 2);
  45         if (!strv)
  46                 return (void) log_oom();
  47
  48         strv[0] = TAKE_PTR(p); /* Note that keyring_read() will NUL terminate implicitly, hence we don't have
  49                                 * to NUL terminate manually here: it's a valid string. */
  50         strv[1] = NULL;
  51
  52         strv_free_erase(cache->keyring_passswords);
  53         cache->keyring_passswords = strv;
  54
  55         log_debug("Successfully acquired home key from kernel keyring.");
  56 }