2 * @file libcryptsetup.h
3 * @brief Public cryptsetup API
5 * For more verbose examples of LUKS related use cases,
6 * please read @ref index "examples".
9 #ifndef _LIBCRYPTSETUP_H
10 #define _LIBCRYPTSETUP_H
17 struct crypt_device; /* crypt device handle */
20 * Initialize crypt device handle and check if provided device exists.
22 * @param cd Returns pointer to crypt device handle
23 * @param device Path to the backing device.
24 * If @e device is not a block device but a path to some file,
25 * the function will try to create a loopdevice and attach
26 * the file to the loopdevice with AUTOCLEAR flag set.
27 * If @e device is @e NULL function it will initialize dm backend only.
29 * @return @e 0 on success or negative errno value otherwise.
31 * @note Note that logging is not initialized here, possible messages uses
32 * default log function.
34 int crypt_init(struct crypt_device **cd, const char *device);
37 * Initialize crypt device handle from provided active device name,
38 * and, optionally, from separate metadata (header) device
39 * and check if provided device exists.
41 * @return @e 0 on success or negative errno value otherwise.
43 * @param cd returns crypt device handle for active device
44 * @param name name of active crypt device
45 * @param header_device optional device containing on-disk header
46 * (@e NULL if it the same as underlying device on there is no on-disk header)
48 * @post In case @e device points to active LUKS device but header load fails,
49 * context device type is set to @e NULL and @e 0 is returned as if it were successful.
50 * Context with @e NULL device type can only be deactivated by crypt_deactivate
52 * @note @link crypt_init_by_name @endlink is equivalent to calling
53 * crypt_init_by_name_and_header(cd, name, NULL);
55 int crypt_init_by_name_and_header(struct crypt_device **cd,
57 const char *header_device);
60 * This is equivalent to call
61 * @ref crypt_init_by_name_and_header "crypt_init_by_name_and_header(cd, name, NULL)"
63 * @sa crypt_init_by_name_and_header
65 int crypt_init_by_name(struct crypt_device **cd, const char *name);
68 * @defgroup loglevel "Cryptsetup logging"
70 * Set of functions and defines used in cryptsetup for
76 * @addtogroup loglevel
80 /** normal log level */
81 #define CRYPT_LOG_NORMAL 0
82 /** error log level */
83 #define CRYPT_LOG_ERROR 1
84 /** verbose log level */
85 #define CRYPT_LOG_VERBOSE 2
86 /** debug log level - always on stdout */
87 #define CRYPT_LOG_DEBUG -1
92 * @param cd crypt device handle (can be @e NULL to set default log function)
93 * @param log user defined log function reference
94 * @param usrptr provided identification in callback
95 * @param level log level below (debug messages can uses other levels)
96 * @param msg log message
98 void crypt_set_log_callback(struct crypt_device *cd,
99 void (*log)(int level, const char *msg, void *usrptr),
103 * Defines log function or use the default one otherwise.
105 * @see crypt_set_log_callback
107 * @param cd crypt device handle
108 * @param level log level
109 * @param msg log message
111 void crypt_log(struct crypt_device *cd, int level, const char *msg);
115 * Set confirmation callback (yes/no)
117 * If code need confirmation (like resetting uuid or restoring LUKS header from file)
118 * this function is called. If not defined, everything is confirmed.
120 * Callback function @e confirm should return @e 0 if operation is declined,
121 * other values mean accepted.
123 * @param cd crypt device handle
124 * @param confirm user defined confirm callback reference
125 * @param usrptr provided identification in callback
126 * @param msg Message for user to confirm
128 * @note Current version of cryptsetup API requires confirmation only when UUID is being changed
130 void crypt_set_confirm_callback(struct crypt_device *cd,
131 int (*confirm)(const char *msg, void *usrptr),
135 * Set password query callback.
137 * If code need @e _interactive_ query for password, this callback is called.
138 * If not defined, compiled-in default is called (uses terminal input).
140 * Callback should return length of password in buffer
141 * or negative errno value in case of error.
143 * @param cd crypt device handle
144 * @param password user defined password callback reference
145 * @param usrptr provided identification in callback
146 * @param msg Message for user
147 * @param buf buffer for password
148 * @param length size of buffer
150 * @note Note that if this function is defined, verify option is ignored
151 * (caller which provided callback is responsible for password verification)
152 * @note Only zero terminated passwords can be entered this way, for complex
153 * use API functions directly.
154 * @note Maximal length of password is limited to @e length @e - @e 1 (minimal 511 chars)
156 * @see Callback function is used in these call provided, that certain conditions are met:
157 * @li crypt_keyslot_add_by_passphrase
158 * @li crypt_activate_by_passphrase
159 * @li crypt_resume_by_passphrase
160 * @li crypt_resume_by_keyfile
161 * @li crypt_keyslot_add_by_keyfile
162 * @li crypt_keyslot_add_by_volume_key
165 void crypt_set_password_callback(struct crypt_device *cd,
166 int (*password)(const char *msg, char *buf, size_t length, void *usrptr),
170 * Set timeout for interactive password entry using default
173 * @param cd crypt device handle
174 * @param timeout_sec timeout in seconds
176 void crypt_set_timeout(struct crypt_device *cd, uint64_t timeout_sec);
179 * Set number of retries in case password input has been incorrect
181 * @param cd crypt device handle
182 * @param tries the number
184 void crypt_set_password_retry(struct crypt_device *cd, int tries);
187 * Set how long should cryptsetup iterate in PBKDF2 function.
188 * Default value heads towards the iterations which takes around 1 second
190 * @param cd crypt device handle
191 * @param iteration_time_ms the time in ms
193 void crypt_set_iterarion_time(struct crypt_device *cd, uint64_t iteration_time_ms);
196 * Set whether passphrase will be verified on input
197 * (user has to input same passphrase twice)
199 * @param cd crypt device handle
200 * @param password_verify @e 0 = false, @e !0 true
202 void crypt_set_password_verify(struct crypt_device *cd, int password_verify);
205 * Set data device (encrypted payload area device) if LUKS header is separated
207 * @param cd crypt device handle
208 * @param device path to device
210 * @pre context is of LUKS type
211 * @pre unlike @ref crypt_init, in this function param @e device
212 * has to be block device (at least 512B large)
214 int crypt_set_data_device(struct crypt_device *cd, const char *device);
217 * @defgroup rng "Cryptsetup RNG"
224 /** CRYPT_RNG_URANDOM - use /dev/urandom */
225 #define CRYPT_RNG_URANDOM 0
226 /** CRYPT_RNG_RANDOM - use /dev/random (waits if no entropy in system) */
227 #define CRYPT_RNG_RANDOM 1
230 * Set which RNG (random number generator) is used for generating long term key
232 * @param cd crypt device handle
233 * @param rng_type kernel random number generator to use
236 void crypt_set_rng_type(struct crypt_device *cd, int rng_type);
239 * Get which RNG (random number generator) is used for generating long term key
241 * @param cd crypt device handle
242 * @return RNG type on success or negative errno value otherwise.
245 int crypt_get_rng_type(struct crypt_device *cd);
250 * Helper to lock/unlock memory to avoid swap sensitive data to disk
252 * @param cd crypt device handle, can be @e NULL
253 * @param lock 0 to unlock otherwise lock memory
255 * @returns Value indicating whether the memory is locked (function can be called multiple times).
257 * @note Only root can do this.
258 * @note It locks/unlocks all process memory, not only crypt context.
260 int crypt_memory_lock(struct crypt_device *cd, int lock);
263 * @defgroup crypt_type "Cryptsetup on-disk format types"
265 * Set of functions, \#defines and structs related
266 * to on-disk format types
270 * @addtogroup crypt_type
274 /** regular crypt device, no on-disk header */
275 #define CRYPT_PLAIN "PLAIN"
276 /** LUKS version 1 header on-disk */
277 #define CRYPT_LUKS1 "LUKS1"
278 /** loop-AES compatibility mode */
279 #define CRYPT_LOOPAES "LOOPAES"
284 * @param cd crypt device handle
285 * @return string according to device type or @e NULL if not known.
287 const char *crypt_get_type(struct crypt_device *cd);
291 * Structure used as parameter for PLAIN device type
295 struct crypt_params_plain {
296 const char *hash; /**< password hash function */
297 uint64_t offset; /**< offset in sectors */
298 uint64_t skip; /**< IV offset / initialization sector */
299 uint64_t size; /**< size of mapped device or @e 0 for autodetection */
303 * Structure used as parameter for LUKS device type
305 * @see crypt_format, crypt_load
307 * @note during crypt_format @e data_device attribute determines
308 * if the LUKS header is separated from encrypted payload device
311 struct crypt_params_luks1 {
312 const char *hash; /**< hash used in LUKS header */
313 size_t data_alignment; /**< data alignment in sectors, data offset is multiple of this */
314 const char *data_device; /**< detached encrypted data device or @e NULL */
319 * Structure used as parameter for loop-AES device type
324 struct crypt_params_loopaes {
325 const char *hash; /**< key hash function */
326 uint64_t offset; /**< offset in sectors */
327 uint64_t skip; /**< IV offset / initialization sector */
333 * Create (format) new crypt device (and possible header on-disk) but not activates it.
335 * @pre @e cd contains initialized and not formatted device context (device type must @b not be set)
337 * @param cd crypt device handle
338 * @param type type of device (optional params struct must be of this type)
339 * @param cipher (e.g. "aes")
340 * @param cipher_mode including IV specification (e.g. "xts-plain")
341 * @param uuid requested UUID or @e NULL if it should be generated
342 * @param volume_key pre-generated volume key or @e NULL if it should be generated (only for LUKS)
343 * @param volume_key_size size of volume key in bytes.
344 * @param params crypt type specific parameters (see @link crypt_type @endlink)
346 * @returns @e 0 on success or negative errno value otherwise.
348 * @note Note that crypt_format does not enable any keyslot (in case of work with LUKS device), but it stores volume key internally
349 * and subsequent crypt_keyslot_add_* calls can be used.
351 int crypt_format(struct crypt_device *cd,
354 const char *cipher_mode,
356 const char *volume_key,
357 size_t volume_key_size,
361 * Set new UUID for already existing device
363 * @param cd crypt device handle
364 * @param uuid requested UUID or @e NULL if it should be generated
366 * @returns 0 on success or negative errno value otherwise.
368 * @note Currently, only LUKS device type are supported
370 int crypt_set_uuid(struct crypt_device *cd,
374 * Load crypt device parameters from on-disk header
376 * @param cd crypt device handle
377 * @param requested_type - use @e NULL for all known
378 * @param params crypt type specific parameters (see @link crypt_type @endlink)
380 * @returns 0 on success or negative errno value otherwise.
382 * @post In case LUKS header is read successfully but payload device is too small
383 * error is returned and device type in context is set to @e NULL
385 * @note Note that in current version load works only for LUKS device type
388 int crypt_load(struct crypt_device *cd,
389 const char *requested_type,
393 * Resize crypt device
395 * @param cd - crypt device handle
396 * @param name - name of device to resize
397 * @param new_size - new device size in sectors or @e 0 to use all of the underlying device size
399 * @return @e 0 on success or negative errno value otherwise.
401 int crypt_resize(struct crypt_device *cd,
406 * Suspends crypt device.
408 * @param cd crypt device handle, can be @e NULL
409 * @param name name of device to suspend
411 * @return 0 on success or negative errno value otherwise.
413 * @note Only LUKS device type is supported
416 int crypt_suspend(struct crypt_device *cd,
420 * Resumes crypt device using passphrase.
423 * @param cd crypt device handle
424 * @param name name of device to resume
425 * @param keyslot requested keyslot or CRYPT_ANY_SLOT
426 * @param passphrase passphrase used to unlock volume key, @e NULL for query
427 * @param passphrase_size size of @e passphrase (binary data)
429 * @return unlocked key slot number or negative errno otherwise.
431 * @note Only LUKS device type is supported
433 int crypt_resume_by_passphrase(struct crypt_device *cd,
436 const char *passphrase,
437 size_t passphrase_size);
440 * Resumes crypt device using key file.
442 * @param cd crypt device handle
443 * @param name name of device to resume
444 * @param keyslot requested keyslot or CRYPT_ANY_SLOT
445 * @param keyfile key file used to unlock volume key, @e NULL for passphrase query
446 * @param keyfile_size number of bytes to read from keyfile, 0 is unlimited
448 * @return unlocked key slot number or negative errno otherwise.
450 int crypt_resume_by_keyfile(struct crypt_device *cd,
454 size_t keyfile_size);
457 * Releases crypt device context and used memory.
459 * @param cd crypt device handle
461 void crypt_free(struct crypt_device *cd);
464 * @defgroup keyslot "Cryptsetup LUKS keyslots"
465 * @addtogroup keyslot
470 /** iterate through all keyslots and find first one that fits */
471 #define CRYPT_ANY_SLOT -1
474 * Add key slot using provided passphrase
476 * @pre @e cd contains initialized and formatted LUKS device context
478 * @param cd crypt device handle
479 * @param keyslot requested keyslot or @e CRYPT_ANY_SLOT
480 * @param passphrase passphrase used to unlock volume key, @e NULL for query
481 * @param passphrase_size size of passphrase (binary data)
482 * @param new_passphrase passphrase for new keyslot, @e NULL for query
483 * @param new_passphrase_size size of @e new_passphrase (binary data)
485 * @return allocated key slot number or negative errno otherwise.
487 int crypt_keyslot_add_by_passphrase(struct crypt_device *cd,
489 const char *passphrase,
490 size_t passphrase_size,
491 const char *new_passphrase,
492 size_t new_passphrase_size);
495 * Get number of keyslots supported for device type.
497 * @param type crypt device type
499 * @return slot count or negative errno otherwise if device
500 * doesn't not support keyslots.
502 int crypt_keyslot_max(const char *type);
505 * Add key slot using provided key file path
507 * @pre @e cd contains initialized and formatted LUKS device context
509 * @param cd crypt device handle
510 * @param keyslot requested keyslot or @e CRYPT_ANY_SLOT
511 * @param keyfile key file used to unlock volume key, @e NULL for passphrase query
512 * @param keyfile_size number of bytes to read from keyfile, @e 0 is unlimited
513 * @param new_keyfile keyfile for new keyslot, @e NULL for passphrase query
514 * @param new_keyfile_size number of bytes to read from @e new_keyfile, @e 0 is unlimited
516 * @return allocated key slot number or negative errno otherwise.
518 * @note Note that @e keyfile can be "-" for STDIN
521 int crypt_keyslot_add_by_keyfile(struct crypt_device *cd,
525 const char *new_keyfile,
526 size_t new_keyfile_size);
529 * Add key slot using provided volume key
531 * @pre @e cd contains initialized and formatted LUKS device context
533 * @param cd crypt device handle
534 * @param keyslot requested keyslot or CRYPT_ANY_SLOT
535 * @param volume_key provided volume key or @e NULL if used after crypt_format
536 * @param volume_key_size size of volume_key
537 * @param passphrase passphrase for new keyslot, @e NULL for query
538 * @param passphrase_size size of passphrase
540 * @return allocated key slot number or negative errno otherwise.
543 int crypt_keyslot_add_by_volume_key(struct crypt_device *cd,
545 const char *volume_key,
546 size_t volume_key_size,
547 const char *passphrase,
548 size_t passphrase_size);
551 * Destroy (and disable) key slot
553 * @pre @e cd contains initialized and formatted LUKS device context
555 * @param cd crypt device handle
556 * @param keyslot requested key slot to destroy
558 * @return @e 0 on success or negative errno value otherwise.
560 * @note Note that there is no passphrase verification used.
562 int crypt_keyslot_destroy(struct crypt_device *cd, int keyslot);
567 * @defgroup aflags "Device runtime attributes"
575 /** device is read only */
576 #define CRYPT_ACTIVATE_READONLY (1 << 0)
578 #define CRYPT_ACTIVATE_NO_UUID (1 << 1)
580 #define CRYPT_ACTIVATE_SHARED (1 << 2)
581 /** enable discards aka TRIM */
582 #define CRYPT_ACTIVATE_ALLOW_DISCARDS (1 << 3)
585 * Active device runtime attributes
587 struct crypt_active_device {
588 uint64_t offset; /**< offset in sectors */
589 uint64_t iv_offset; /**< IV initialization sector */
590 uint64_t size; /**< active device size */
591 uint32_t flags; /**< activation flags */
595 * Receives runtime attributes of active crypt device
597 * @param cd crypt device handle (can be @e NULL)
598 * @param name name of active device
599 * @param cad preallocated active device attributes to fill
601 * @return @e 0 on success or negative errno value otherwise
604 int crypt_get_active_device(struct crypt_device *cd,
606 struct crypt_active_device *cad);
611 * Activate device or check passphrase
613 * @param cd crypt device handle
614 * @param name name of device to create, if @e NULL only check passphrase
615 * @param keyslot requested keyslot to check or @e CRYPT_ANY_SLOT
616 * @param passphrase passphrase used to unlock volume key, @e NULL for query
617 * @param passphrase_size size of @e passphrase
618 * @param flags activation flags
620 * @return unlocked key slot number or negative errno otherwise.
622 int crypt_activate_by_passphrase(struct crypt_device *cd,
625 const char *passphrase,
626 size_t passphrase_size,
630 * Activate device or check using key file
632 * @param cd crypt device handle
633 * @param name name of device to create, if @e NULL only check keyfile
634 * @param keyslot requested keyslot to check or CRYPT_ANY_SLOT
635 * @param keyfile key file used to unlock volume key
636 * @param keyfile_size number of bytes to read from keyfile, 0 is unlimited
637 * @param flags activation flags
639 * @return unlocked key slot number or negative errno otherwise.
641 int crypt_activate_by_keyfile(struct crypt_device *cd,
649 * Activate device using provided volume key
652 * @param cd crypt device handle
653 * @param name name of device to create, if @e NULL only check volume key
654 * @param volume_key provided volume key (or @e NULL to use internal)
655 * @param volume_key_size size of volume_key
656 * @param flags activation flags
658 * @return @e 0 on success or negative errno value otherwise.
660 * @note If @e NULL is used for volume_key, device has to be initialized
661 * by previous operation (like @ref crypt_format
662 * or @ref crypt_init_by_name)
664 int crypt_activate_by_volume_key(struct crypt_device *cd,
666 const char *volume_key,
667 size_t volume_key_size,
671 * Deactivate crypt device. This function tries to remove active device-mapper
672 * mapping from kernel. Also, sensitive data like the volume key are removed from
675 * @param cd crypt device handle, can be @e NULL
676 * @param name name of device to deactivate
678 * @return @e 0 on success or negative errno value otherwise.
681 int crypt_deactivate(struct crypt_device *cd, const char *name);
684 * Get volume key from of crypt device
686 * @param cd crypt device handle
687 * @param keyslot use this keyslot or @e CRYPT_ANY_SLOT
688 * @param volume_key buffer for volume key
689 * @param volume_key_size on input, size of buffer @e volume_key,
690 * on output size of @e volume_key
691 * @param passphrase passphrase used to unlock volume key
692 * @param passphrase_size size of @e passphrase
694 * @return unlocked key slot number or negative errno otherwise.
696 int crypt_volume_key_get(struct crypt_device *cd,
699 size_t *volume_key_size,
700 const char *passphrase,
701 size_t passphrase_size);
704 * Verify that provided volume key is valid for crypt device
706 * @param cd crypt device handle
707 * @param volume_key provided volume key
708 * @param volume_key_size size of @e volume_key
710 * @return @e 0 on success or negative errno value otherwise.
712 int crypt_volume_key_verify(struct crypt_device *cd,
713 const char *volume_key,
714 size_t volume_key_size);
718 * @defgroup devstat "dmcrypt device status"
719 * @addtogroup devstat
727 CRYPT_INVALID, /**< device mapping is invalid in this context */
728 CRYPT_INACTIVE, /**< no such mapped device */
729 CRYPT_ACTIVE, /**< device is active */
730 CRYPT_BUSY /**< device is active and has open count > 0 */
734 * Get status info about device name
736 * @param cd crypt device handle, can be @e NULL
737 * @param name crypt device name
739 * @return value defined by crypt_status_info.
742 crypt_status_info crypt_status(struct crypt_device *cd, const char *name);
745 * Dump text-formatted information about crypt device to log output
747 * @param cd crypt device handle
749 * @return @e 0 on success or negative errno value otherwise.
751 int crypt_dump(struct crypt_device *cd);
754 * Get cipher used in device
756 * @param cd crypt device handle
758 * @return used cipher, e.g. "aes" or @e NULL otherwise
761 const char *crypt_get_cipher(struct crypt_device *cd);
764 * Get cipher mode used in device
766 * @param cd crypt device handle
768 * @return used cipher mode e.g. "xts-plain" or @e otherwise
771 const char *crypt_get_cipher_mode(struct crypt_device *cd);
776 * @param cd crypt device handle
778 * @return device UUID or @e NULL if not set
781 const char *crypt_get_uuid(struct crypt_device *cd);
784 * Get path to underlaying device
786 * @param cd crypt device handle
788 * @return path to underlaying device name
791 const char *crypt_get_device_name(struct crypt_device *cd);
794 * Get device offset in sectors where real data starts on underlying device)
796 * @param cd crypt device handle
798 * @return device offset in sectors
801 uint64_t crypt_get_data_offset(struct crypt_device *cd);
804 * Get IV offset in sectors (skip)
806 * @param cd crypt device handle
811 uint64_t crypt_get_iv_offset(struct crypt_device *cd);
814 * Get size (in bytes) of volume key for crypt device
816 * @param cd crypt device handle
818 * @return volume key size
821 int crypt_get_volume_key_size(struct crypt_device *cd);
824 * @addtogroup keyslot
833 CRYPT_SLOT_INVALID, /**< invalid keyslot */
834 CRYPT_SLOT_INACTIVE, /**< keyslot is inactive (free) */
835 CRYPT_SLOT_ACTIVE, /**< keyslot is active (used) */
836 CRYPT_SLOT_ACTIVE_LAST /**< keylost is active (used)
837 * and last used at the same time */
838 } crypt_keyslot_info;
841 * Get information about particular key slot
844 * @param cd crypt device handle
845 * @param keyslot requested keyslot to check or CRYPT_ANY_SLOT
847 * @return value defined by crypt_keyslot_info
850 crypt_keyslot_info crypt_keyslot_status(struct crypt_device *cd, int keyslot);
854 * Backup header and keyslots to file
856 * @param cd crypt device handle
857 * @param requested_type type of header to backup
858 * @param backup_file file to backup header to
860 * @return @e 0 on success or negative errno value otherwise.
863 int crypt_header_backup(struct crypt_device *cd,
864 const char *requested_type,
865 const char *backup_file);
868 * Restore header and keyslots from backup file
871 * @param cd crypt device handle
872 * @param requested_type type of header to restore
873 * @param backup_file file to restore header from
875 * @return @e 0 on success or negative errno value otherwise.
878 int crypt_header_restore(struct crypt_device *cd,
879 const char *requested_type,
880 const char *backup_file);
883 * Receives last reported error
885 * @param cd crypt device handle
886 * @param buf buffef for message
887 * @param size size of buffer
889 * @note Note that this is old API function using global context.
890 * All error messages are reported also through log callback.
892 void crypt_last_error(struct crypt_device *cd, char *buf, size_t size);
895 * Receives last reported error, DEPRECATED
897 * @param buf buffef for message
898 * @param size size of buffer
900 * @note Note that this is old API function using global context.
901 * All error messages are reported also through log callback.
903 void crypt_get_error(char *buf, size_t size);
906 * Get directory where mapped crypt devices are created
908 * @return the directory path
910 const char *crypt_get_dir(void);
913 * @defgroup dbg "Library debug level"
915 * Set library debug level
922 #define CRYPT_DEBUG_ALL -1
924 #define CRYPT_DEBUG_NONE 0
927 * Set the debug level for library
929 * @param level debug level
932 void crypt_set_debug_level(int level);
939 #endif /* _LIBCRYPTSETUP_H */