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 #if HAVE_CRYPT_REENCRYPT_INIT_BY_PASSPHRASE
  53 int (*sym_crypt_reencrypt_init_by_passphrase)(struct crypt_device *cd, const char *name, const char *passphrase, size_t passphrase_size, int keyslot_old, int keyslot_new, const char *cipher, const char *cipher_mode, const struct crypt_params_reencrypt *params);
  54 #endif
  55 #if HAVE_CRYPT_REENCRYPT
  56 int (*sym_crypt_reencrypt)(struct crypt_device *cd, int (*progress)(uint64_t size, uint64_t offset, void *usrptr));
  57 #endif
  58 int (*sym_crypt_metadata_locking)(struct crypt_device *cd, int enable);
  59 #if HAVE_CRYPT_SET_DATA_OFFSET
  60 int (*sym_crypt_set_data_offset)(struct crypt_device *cd, uint64_t data_offset);
  61 #endif
  62 int (*sym_crypt_header_restore)(struct crypt_device *cd, const char *requested_type, const char *backup_file);
  63 int (*sym_crypt_volume_key_keyring)(struct crypt_device *cd, int enable);
  64
  65 static void cryptsetup_log_glue(int level, const char *msg, void *usrptr) {
  66
  67         switch (level) {
  68         case CRYPT_LOG_NORMAL:
  69                 level = LOG_NOTICE;
  70                 break;
  71         case CRYPT_LOG_ERROR:
  72                 level = LOG_ERR;
  73                 break;
  74         case CRYPT_LOG_VERBOSE:
  75                 level = LOG_INFO;
  76                 break;
  77         case CRYPT_LOG_DEBUG:
  78                 level = LOG_DEBUG;
  79                 break;
  80         default:
  81                 log_error("Unknown libcryptsetup log level: %d", level);
  82                 level = LOG_ERR;
  83         }
  84
  85         log_full(level, "%s", msg);
  86 }
  87
  88 void cryptsetup_enable_logging(struct crypt_device *cd) {
  89         /* It's OK to call this with a NULL parameter, in which case libcryptsetup will set the default log
  90          * function.
  91          *
  92          * Note that this is also called from dlopen_cryptsetup(), which we call here too. Sounds like an
  93          * endless loop, but isn't because we break it via the check for 'cryptsetup_dl' early in
  94          * dlopen_cryptsetup(). */
  95
  96         if (dlopen_cryptsetup() < 0)
  97                 return; /* If this fails, let's gracefully ignore the issue, this is just debug logging after
  98                          * all, and if this failed we already generated a debug log message that should help
  99                          * to track things down. */
 100
 101         sym_crypt_set_log_callback(cd, cryptsetup_log_glue, NULL);
 102         sym_crypt_set_debug_level(DEBUG_LOGGING ? CRYPT_DEBUG_ALL : CRYPT_DEBUG_NONE);
 103 }
 104
 105 int cryptsetup_set_minimal_pbkdf(struct crypt_device *cd) {
 106
 107         /* With CRYPT_PBKDF_NO_BENCHMARK flag set .time_ms member is ignored
 108          * while .iterations must be set at least to recommended minimum value. */
 109
 110         static const struct crypt_pbkdf_type minimal_pbkdf = {
 111                 .hash = "sha512",
 112                 .type = CRYPT_KDF_PBKDF2,
 113                 .iterations = 1000, /* recommended minimum count for pbkdf2
 114                                      * according to NIST SP 800-132, ch. 5.2 */
 115                 .flags = CRYPT_PBKDF_NO_BENCHMARK
 116         };
 117
 118         int r;
 119
 120         /* Sets a minimal PKBDF in case we already have a high entropy key. */
 121
 122         r = dlopen_cryptsetup();
 123         if (r < 0)
 124                 return r;
 125
 126         r = sym_crypt_set_pbkdf_type(cd, &minimal_pbkdf);
 127         if (r < 0)
 128                 return r;
 129
 130         return 0;
 131 }
 132
 133 int cryptsetup_get_token_as_json(
 134                 struct crypt_device *cd,
 135                 int idx,
 136                 const char *verify_type,
 137                 JsonVariant **ret) {
 138
 139         _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
 140         const char *text;
 141         int r;
 142
 143         assert(cd);
 144
 145         /* Extracts and parses the LUKS2 JSON token data from a LUKS2 device. Optionally verifies the type of
 146          * the token. Returns:
 147          *
 148          *      -EINVAL → token index out of range or "type" field missing
 149          *      -ENOENT → token doesn't exist
 150          * -EMEDIUMTYPE → "verify_type" specified and doesn't match token's type
 151          */
 152
 153         r = dlopen_cryptsetup();
 154         if (r < 0)
 155                 return r;
 156
 157         r = sym_crypt_token_json_get(cd, idx, &text);
 158         if (r < 0)
 159                 return r;
 160
 161         r = json_parse(text, 0, &v, NULL, NULL);
 162         if (r < 0)
 163                 return r;
 164
 165         if (verify_type) {
 166                 JsonVariant *w;
 167
 168                 w = json_variant_by_key(v, "type");
 169                 if (!w)
 170                         return -EINVAL;
 171
 172                 if (!streq_ptr(json_variant_string(w), verify_type))
 173                         return -EMEDIUMTYPE;
 174         }
 175
 176         if (ret)
 177                 *ret = TAKE_PTR(v);
 178
 179         return 0;
 180 }
 181
 182 int cryptsetup_add_token_json(struct crypt_device *cd, JsonVariant *v) {
 183         _cleanup_free_ char *text = NULL;
 184         int r;
 185
 186         r = dlopen_cryptsetup();
 187         if (r < 0)
 188                 return r;
 189
 190         r = json_variant_format(v, 0, &text);
 191         if (r < 0)
 192                 return log_debug_errno(r, "Failed to format token data for LUKS: %m");
 193
 194         log_debug("Adding token text <%s>", text);
 195
 196         r = sym_crypt_token_json_set(cd, CRYPT_ANY_TOKEN, text);
 197         if (r < 0)
 198                 return log_debug_errno(r, "Failed to write token data to LUKS: %m");
 199
 200         return 0;
 201 }
 202 #endif
 203
 204 int dlopen_cryptsetup(void) {
 205 #if HAVE_LIBCRYPTSETUP
 206         int r;
 207
 208         /* libcryptsetup added crypt_reencrypt() in 2.2.0, and marked it obsolete in 2.4.0, replacing it with
 209          * crypt_reencrypt_run(), which takes one extra argument but is otherwise identical. The old call is
 210          * still available though, and given we want to support 2.2.0 for a while longer, we'll stick to the
 211          * old symbol. Howerver, the old symbols now has a GCC deprecation decorator, hence let's turn off
 212          * warnings about this for now. */
 213
 214         DISABLE_WARNING_DEPRECATED_DECLARATIONS;
 215
 216         r = dlopen_many_sym_or_warn(
 217                         &cryptsetup_dl, "libcryptsetup.so.12", LOG_DEBUG,
 218                         DLSYM_ARG(crypt_activate_by_passphrase),
 219 #if HAVE_CRYPT_ACTIVATE_BY_SIGNED_KEY
 220                         DLSYM_ARG(crypt_activate_by_signed_key),
 221 #endif
 222                         DLSYM_ARG(crypt_activate_by_volume_key),
 223                         DLSYM_ARG(crypt_deactivate_by_name),
 224                         DLSYM_ARG(crypt_format),
 225                         DLSYM_ARG(crypt_free),
 226                         DLSYM_ARG(crypt_get_cipher),
 227                         DLSYM_ARG(crypt_get_cipher_mode),
 228                         DLSYM_ARG(crypt_get_data_offset),
 229                         DLSYM_ARG(crypt_get_device_name),
 230                         DLSYM_ARG(crypt_get_dir),
 231                         DLSYM_ARG(crypt_get_type),
 232                         DLSYM_ARG(crypt_get_uuid),
 233                         DLSYM_ARG(crypt_get_verity_info),
 234                         DLSYM_ARG(crypt_get_volume_key_size),
 235                         DLSYM_ARG(crypt_init),
 236                         DLSYM_ARG(crypt_init_by_name),
 237                         DLSYM_ARG(crypt_keyslot_add_by_volume_key),
 238                         DLSYM_ARG(crypt_keyslot_destroy),
 239                         DLSYM_ARG(crypt_keyslot_max),
 240                         DLSYM_ARG(crypt_load),
 241                         DLSYM_ARG(crypt_resize),
 242                         DLSYM_ARG(crypt_resume_by_passphrase),
 243                         DLSYM_ARG(crypt_set_data_device),
 244                         DLSYM_ARG(crypt_set_debug_level),
 245                         DLSYM_ARG(crypt_set_log_callback),
 246 #if HAVE_CRYPT_SET_METADATA_SIZE
 247                         DLSYM_ARG(crypt_set_metadata_size),
 248 #endif
 249                         DLSYM_ARG(crypt_set_pbkdf_type),
 250                         DLSYM_ARG(crypt_suspend),
 251                         DLSYM_ARG(crypt_token_json_get),
 252                         DLSYM_ARG(crypt_token_json_set),
 253 #if HAVE_CRYPT_TOKEN_MAX
 254                         DLSYM_ARG(crypt_token_max),
 255 #endif
 256                         DLSYM_ARG(crypt_token_status),
 257                         DLSYM_ARG(crypt_volume_key_get),
 258 #if HAVE_CRYPT_REENCRYPT_INIT_BY_PASSPHRASE
 259                         DLSYM_ARG(crypt_reencrypt_init_by_passphrase),
 260 #endif
 261 #if HAVE_CRYPT_REENCRYPT
 262                         DLSYM_ARG(crypt_reencrypt),
 263 #endif
 264                         DLSYM_ARG(crypt_metadata_locking),
 265 #if HAVE_CRYPT_SET_DATA_OFFSET
 266                         DLSYM_ARG(crypt_set_data_offset),
 267 #endif
 268                         DLSYM_ARG(crypt_header_restore),
 269                         DLSYM_ARG(crypt_volume_key_keyring));
 270         if (r <= 0)
 271                 return r;
 272
 273         REENABLE_WARNING;
 274
 275         /* Redirect the default logging calls of libcryptsetup to our own logging infra. (Note that
 276          * libcryptsetup also maintains per-"struct crypt_device" log functions, which we'll also set
 277          * whenever allocating a "struct crypt_device" context. Why set both? To be defensive: maybe some
 278          * other code loaded into this process also changes the global log functions of libcryptsetup, who
 279          * knows? And if so, we still want our own objects to log via our own infra, at the very least.) */
 280         cryptsetup_enable_logging(NULL);
 281         return 1;
 282 #else
 283         return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "cryptsetup support is not compiled in.");
 284 #endif
 285 }
 286
 287 int cryptsetup_get_keyslot_from_token(JsonVariant *v) {
 288         int keyslot, r;
 289         JsonVariant *w;
 290
 291         /* Parses the "keyslots" field of a LUKS2 token object. The field can be an array, but here we assume
 292          * that it contains a single element only, since that's the only way we ever generate it
 293          * ourselves. */
 294
 295         w = json_variant_by_key(v, "keyslots");
 296         if (!w)
 297                 return -ENOENT;
 298         if (!json_variant_is_array(w) || json_variant_elements(w) != 1)
 299                 return -EMEDIUMTYPE;
 300
 301         w = json_variant_by_index(w, 0);
 302         if (!w)
 303                 return -ENOENT;
 304         if (!json_variant_is_string(w))
 305                 return -EMEDIUMTYPE;
 306
 307         r = safe_atoi(json_variant_string(w), &keyslot);
 308         if (r < 0)
 309                 return r;
 310         if (keyslot < 0)
 311                 return -EINVAL;
 312
 313         return keyslot;
 314 }