src/shared/cryptsetup-util.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include "alloc-util.h"
   4 #include "cryptsetup-util.h"
   5 #include "dlfcn-util.h"
   6 #include "log.h"
   7 #include "parse-util.h"
   8
   9 #if HAVE_LIBCRYPTSETUP
  10 static void *cryptsetup_dl = NULL;
  11
  12 int (*sym_crypt_activate_by_passphrase)(struct crypt_device *cd, const char *name, int keyslot, const char *passphrase, size_t passphrase_size, uint32_t flags);
  13 #if HAVE_CRYPT_ACTIVATE_BY_SIGNED_KEY
  14 int (*sym_crypt_activate_by_signed_key)(struct crypt_device *cd, const char *name, const char *volume_key, size_t volume_key_size, const char *signature, size_t signature_size, uint32_t flags);
  15 #endif
  16 int (*sym_crypt_activate_by_volume_key)(struct crypt_device *cd, const char *name, const char *volume_key, size_t volume_key_size, uint32_t flags);
  17 int (*sym_crypt_deactivate_by_name)(struct crypt_device *cd, const char *name, uint32_t flags);
  18 int (*sym_crypt_format)(struct crypt_device *cd, const char *type, const char *cipher, const char *cipher_mode, const char *uuid, const char *volume_key, size_t volume_key_size, void *params);
  19 void (*sym_crypt_free)(struct crypt_device *cd);
  20 const char *(*sym_crypt_get_cipher)(struct crypt_device *cd);
  21 const char *(*sym_crypt_get_cipher_mode)(struct crypt_device *cd);
  22 uint64_t (*sym_crypt_get_data_offset)(struct crypt_device *cd);
  23 const char *(*sym_crypt_get_device_name)(struct crypt_device *cd);
  24 const char *(*sym_crypt_get_dir)(void);
  25 const char *(*sym_crypt_get_type)(struct crypt_device *cd);
  26 const char *(*sym_crypt_get_uuid)(struct crypt_device *cd);
  27 int (*sym_crypt_get_verity_info)(struct crypt_device *cd, struct crypt_params_verity *vp);
  28 int (*sym_crypt_get_volume_key_size)(struct crypt_device *cd);
  29 int (*sym_crypt_init)(struct crypt_device **cd, const char *device);
  30 int (*sym_crypt_init_by_name)(struct crypt_device **cd, const char *name);
  31 int (*sym_crypt_keyslot_add_by_volume_key)(struct crypt_device *cd, int keyslot, const char *volume_key, size_t volume_key_size, const char *passphrase, size_t passphrase_size);
  32 int (*sym_crypt_keyslot_destroy)(struct crypt_device *cd, int keyslot);
  33 int (*sym_crypt_keyslot_max)(const char *type);
  34 int (*sym_crypt_load)(struct crypt_device *cd, const char *requested_type, void *params);
  35 int (*sym_crypt_resize)(struct crypt_device *cd, const char *name, uint64_t new_size);
  36 int (*sym_crypt_resume_by_passphrase)(struct crypt_device *cd, const char *name, int keyslot, const char *passphrase, size_t passphrase_size);
  37 int (*sym_crypt_set_data_device)(struct crypt_device *cd, const char *device);
  38 void (*sym_crypt_set_debug_level)(int level);
  39 void (*sym_crypt_set_log_callback)(struct crypt_device *cd, void (*log)(int level, const char *msg, void *usrptr), void *usrptr);
  40 #if HAVE_CRYPT_SET_METADATA_SIZE
  41 int (*sym_crypt_set_metadata_size)(struct crypt_device *cd, uint64_t metadata_size, uint64_t keyslots_size);
  42 #endif
  43 int (*sym_crypt_set_pbkdf_type)(struct crypt_device *cd, const struct crypt_pbkdf_type *pbkdf);
  44 int (*sym_crypt_suspend)(struct crypt_device *cd, const char *name);
  45 int (*sym_crypt_token_json_get)(struct crypt_device *cd, int token, const char **json);
  46 int (*sym_crypt_token_json_set)(struct crypt_device *cd, int token, const char *json);
  47 #if HAVE_CRYPT_TOKEN_MAX
  48 int (*sym_crypt_token_max)(const char *type);
  49 #endif
  50 crypt_token_info (*sym_crypt_token_status)(struct crypt_device *cd, int token, const char **type);
  51 int (*sym_crypt_volume_key_get)(struct crypt_device *cd, int keyslot, char *volume_key, size_t *volume_key_size, const char *passphrase, size_t passphrase_size);
  52
  53 int dlopen_cryptsetup(void) {
  54         int r;
  55
  56         r = dlopen_many_sym_or_warn(
  57                         &cryptsetup_dl, "libcryptsetup.so.12", LOG_DEBUG,
  58                         DLSYM_ARG(crypt_activate_by_passphrase),
  59 #if HAVE_CRYPT_ACTIVATE_BY_SIGNED_KEY
  60                         DLSYM_ARG(crypt_activate_by_signed_key),
  61 #endif
  62                         DLSYM_ARG(crypt_activate_by_volume_key),
  63                         DLSYM_ARG(crypt_deactivate_by_name),
  64                         DLSYM_ARG(crypt_format),
  65                         DLSYM_ARG(crypt_free),
  66                         DLSYM_ARG(crypt_get_cipher),
  67                         DLSYM_ARG(crypt_get_cipher_mode),
  68                         DLSYM_ARG(crypt_get_data_offset),
  69                         DLSYM_ARG(crypt_get_device_name),
  70                         DLSYM_ARG(crypt_get_dir),
  71                         DLSYM_ARG(crypt_get_type),
  72                         DLSYM_ARG(crypt_get_uuid),
  73                         DLSYM_ARG(crypt_get_verity_info),
  74                         DLSYM_ARG(crypt_get_volume_key_size),
  75                         DLSYM_ARG(crypt_init),
  76                         DLSYM_ARG(crypt_init_by_name),
  77                         DLSYM_ARG(crypt_keyslot_add_by_volume_key),
  78                         DLSYM_ARG(crypt_keyslot_destroy),
  79                         DLSYM_ARG(crypt_keyslot_max),
  80                         DLSYM_ARG(crypt_load),
  81                         DLSYM_ARG(crypt_resize),
  82                         DLSYM_ARG(crypt_resume_by_passphrase),
  83                         DLSYM_ARG(crypt_set_data_device),
  84                         DLSYM_ARG(crypt_set_debug_level),
  85                         DLSYM_ARG(crypt_set_log_callback),
  86 #if HAVE_CRYPT_SET_METADATA_SIZE
  87                         DLSYM_ARG(crypt_set_metadata_size),
  88 #endif
  89                         DLSYM_ARG(crypt_set_pbkdf_type),
  90                         DLSYM_ARG(crypt_suspend),
  91                         DLSYM_ARG(crypt_token_json_get),
  92                         DLSYM_ARG(crypt_token_json_set),
  93 #if HAVE_CRYPT_TOKEN_MAX
  94                         DLSYM_ARG(crypt_token_max),
  95 #endif
  96                         DLSYM_ARG(crypt_token_status),
  97                         DLSYM_ARG(crypt_volume_key_get));
  98         if (r <= 0)
  99                 return r;
 100
 101         /* Redirect the default logging calls of libcryptsetup to our own logging infra. (Note that
 102          * libcryptsetup also maintains per-"struct crypt_device" log functions, which we'll also set
 103          * whenever allocating a "struct crypt_device" context. Why set both? To be defensive: maybe some
 104          * other code loaded into this process also changes the global log functions of libcryptsetup, who
 105          * knows? And if so, we still want our own objects to log via our own infra, at the very least.) */
 106         cryptsetup_enable_logging(NULL);
 107         return 1;
 108 }
 109
 110 static void cryptsetup_log_glue(int level, const char *msg, void *usrptr) {
 111
 112         switch (level) {
 113         case CRYPT_LOG_NORMAL:
 114                 level = LOG_NOTICE;
 115                 break;
 116         case CRYPT_LOG_ERROR:
 117                 level = LOG_ERR;
 118                 break;
 119         case CRYPT_LOG_VERBOSE:
 120                 level = LOG_INFO;
 121                 break;
 122         case CRYPT_LOG_DEBUG:
 123                 level = LOG_DEBUG;
 124                 break;
 125         default:
 126                 log_error("Unknown libcryptsetup log level: %d", level);
 127                 level = LOG_ERR;
 128         }
 129
 130         log_full(level, "%s", msg);
 131 }
 132
 133 void cryptsetup_enable_logging(struct crypt_device *cd) {
 134         /* It's OK to call this with a NULL parameter, in which case libcryptsetup will set the default log
 135          * function.
 136          *
 137          * Note that this is also called from dlopen_cryptsetup(), which we call here too. Sounds like an
 138          * endless loop, but isn't because we break it via the check for 'cryptsetup_dl' early in
 139          * dlopen_cryptsetup(). */
 140
 141         if (dlopen_cryptsetup() < 0)
 142                 return; /* If this fails, let's gracefully ignore the issue, this is just debug logging after
 143                          * all, and if this failed we already generated a debug log message that should help
 144                          * to track things down. */
 145
 146         sym_crypt_set_log_callback(cd, cryptsetup_log_glue, NULL);
 147         sym_crypt_set_debug_level(DEBUG_LOGGING ? CRYPT_DEBUG_ALL : CRYPT_DEBUG_NONE);
 148 }
 149
 150 int cryptsetup_set_minimal_pbkdf(struct crypt_device *cd) {
 151
 152         /* With CRYPT_PBKDF_NO_BENCHMARK flag set .time_ms member is ignored
 153          * while .iterations must be set at least to recommended minimum value. */
 154
 155         static const struct crypt_pbkdf_type minimal_pbkdf = {
 156                 .hash = "sha512",
 157                 .type = CRYPT_KDF_PBKDF2,
 158                 .iterations = 1000, /* recommended minimum count for pbkdf2
 159                                      * according to NIST SP 800-132, ch. 5.2 */
 160                 .flags = CRYPT_PBKDF_NO_BENCHMARK
 161         };
 162
 163         int r;
 164
 165         /* Sets a minimal PKBDF in case we already have a high entropy key. */
 166
 167         r = dlopen_cryptsetup();
 168         if (r < 0)
 169                 return r;
 170
 171         r = sym_crypt_set_pbkdf_type(cd, &minimal_pbkdf);
 172         if (r < 0)
 173                 return r;
 174
 175         return 0;
 176 }
 177
 178 int cryptsetup_get_token_as_json(
 179                 struct crypt_device *cd,
 180                 int idx,
 181                 const char *verify_type,
 182                 JsonVariant **ret) {
 183
 184         _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
 185         const char *text;
 186         int r;
 187
 188         assert(cd);
 189
 190         /* Extracts and parses the LUKS2 JSON token data from a LUKS2 device. Optionally verifies the type of
 191          * the token. Returns:
 192          *
 193          *      -EINVAL → token index out of range or "type" field missing
 194          *      -ENOENT → token doesn't exist
 195          * -EMEDIUMTYPE → "verify_type" specified and doesn't match token's type
 196          */
 197
 198         r = dlopen_cryptsetup();
 199         if (r < 0)
 200                 return r;
 201
 202         r = sym_crypt_token_json_get(cd, idx, &text);
 203         if (r < 0)
 204                 return r;
 205
 206         r = json_parse(text, 0, &v, NULL, NULL);
 207         if (r < 0)
 208                 return r;
 209
 210         if (verify_type) {
 211                 JsonVariant *w;
 212
 213                 w = json_variant_by_key(v, "type");
 214                 if (!w)
 215                         return -EINVAL;
 216
 217                 if (!streq_ptr(json_variant_string(w), verify_type))
 218                         return -EMEDIUMTYPE;
 219         }
 220
 221         if (ret)
 222                 *ret = TAKE_PTR(v);
 223
 224         return 0;
 225 }
 226
 227 int cryptsetup_add_token_json(struct crypt_device *cd, JsonVariant *v) {
 228         _cleanup_free_ char *text = NULL;
 229         int r;
 230
 231         r = dlopen_cryptsetup();
 232         if (r < 0)
 233                 return r;
 234
 235         r = json_variant_format(v, 0, &text);
 236         if (r < 0)
 237                 return log_debug_errno(r, "Failed to format token data for LUKS: %m");
 238
 239         log_debug("Adding token text <%s>", text);
 240
 241         r = sym_crypt_token_json_set(cd, CRYPT_ANY_TOKEN, text);
 242         if (r < 0)
 243                 return log_debug_errno(r, "Failed to write token data to LUKS: %m");
 244
 245         return 0;
 246 }
 247 #endif
 248
 249 int cryptsetup_get_keyslot_from_token(JsonVariant *v) {
 250         int keyslot, r;
 251         JsonVariant *w;
 252
 253         /* Parses the "keyslots" field of a LUKS2 token object. The field can be an array, but here we assume
 254          * that it contains a single element only, since that's the only way we ever generate it
 255          * ourselves. */
 256
 257         w = json_variant_by_key(v, "keyslots");
 258         if (!w)
 259                 return -ENOENT;
 260         if (!json_variant_is_array(w) || json_variant_elements(w) != 1)
 261                 return -EMEDIUMTYPE;
 262
 263         w = json_variant_by_index(w, 0);
 264         if (!w)
 265                 return -ENOENT;
 266         if (!json_variant_is_string(w))
 267                 return -EMEDIUMTYPE;
 268
 269         r = safe_atoi(json_variant_string(w), &keyslot);
 270         if (r < 0)
 271                 return r;
 272         if (keyslot < 0)
 273                 return -EINVAL;
 274
 275         return keyslot;
 276 }