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         cache->keyring_passswords = strv_free_erase(cache->keyring_passswords);
  15 }
  16
  17 void password_cache_load_keyring(UserRecord *h, PasswordCache *cache) {
  18         _cleanup_(erase_and_freep) void *p = NULL;
  19         _cleanup_free_ char *name = NULL;
  20         char **strv;
  21         key_serial_t serial;
  22         size_t sz;
  23         int r;
  24
  25         assert(h);
  26         assert(cache);
  27
  28         /* Loads the password we need to for automatic resizing from the kernel keyring */
  29
  30         name = strjoin("homework-user-", h->user_name);
  31         if (!name)
  32                 return (void) log_oom();
  33
  34         serial = request_key("user", name, NULL, 0);
  35         if (serial == -1)
  36                 return (void) log_debug_errno(errno, "Failed to request key '%s', ignoring: %m", name);
  37
  38         r = keyring_read(serial, &p, &sz);
  39         if (r < 0)
  40                 return (void) log_debug_errno(r, "Failed to read keyring key '%s', ignoring: %m", name);
  41
  42         if (memchr(p, 0, sz))
  43                 return (void) log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Cached password contains embedded NUL byte, ignoring.");
  44
  45         strv = new(char*, 2);
  46         if (!strv)
  47                 return (void) log_oom();
  48
  49         strv[0] = TAKE_PTR(p); /* Note that keyring_read() will NUL terminate implicitly, hence we don't have
  50                                 * to NUL terminate manually here: it's a valid string. */
  51         strv[1] = NULL;
  52
  53         strv_free_erase(cache->keyring_passswords);
  54         cache->keyring_passswords = strv;
  55
  56         log_debug("Successfully acquired home key from kernel keyring.");
  57 }