cryptsetup/lib/libcryptsetup.h

/*
 * libcryptsetup - cryptsetup library
 *
 * Copyright (C) 2004, Jana Saout <jana@saout.de>
 * Copyright (C) 2004-2007, Clemens Fruhwirth <clemens@endorphin.org>
 * Copyright (C) 2009-2018, Red Hat, Inc. All rights reserved.
 * Copyright (C) 2009-2018, Milan Broz
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

/**
 * @file libcryptsetup.h
 * @brief Public cryptsetup API
 *
 * For more verbose examples of LUKS related use cases,
 * please read @ref index "examples".
 */

#ifndef _LIBCRYPTSETUP_H
#define _LIBCRYPTSETUP_H
#ifdef __cplusplus
extern "C" {
#endif

#include <stddef.h>
#include <stdint.h>

/**
 * @defgroup crypt-init Cryptsetup device context initialization
 * Set of functions for creating and destroying @e crypt_device context
 * @addtogroup crypt-init
 * @{
 */

struct crypt_device; /* crypt device handle */

/**
 * Initialize crypt device handle and check if the provided device exists.
 *
 * @param cd Returns pointer to crypt device handle
 * @param device Path to the backing device.
 * 	  If @e device is not a block device but a path to some file,
 * 	  the function will try to create a loopdevice and attach
 * 	  the file to the loopdevice with AUTOCLEAR flag set.
 * 	  If @e device is @e NULL function it will initialize dm backend only.
 *
 * @return @e 0 on success or negative errno value otherwise.
 *
 * @note Note that logging is not initialized here, possible messages use
 * 	 default log function.
 */
int crypt_init(struct crypt_device **cd, const char *device);

/**
 * Initialize crypt device handle from provided active device name,
 * and, optionally, from separate metadata (header) device
 * and check if provided device exists.
 *
 * @return @e 0 on success or negative errno value otherwise.
 *
 * @param cd returns crypt device handle for active device
 * @param name name of active crypt device
 * @param header_device optional device containing on-disk header
 * 	  (@e NULL if it the same as underlying device on there is no on-disk header)
 *
 * @post In case @e device points to active LUKS device but header load fails,
 * context device type is set to @e NULL and @e 0 is returned as if it were successful.
 * Context with @e NULL device type can only be deactivated by crypt_deactivate
 *
 * @note @link crypt_init_by_name @endlink is equivalent to calling
 * 	 crypt_init_by_name_and_header(cd, name, NULL);
 */
int crypt_init_by_name_and_header(struct crypt_device **cd,
	const char *name,
	const char *header_device);

/**
 * This is equivalent to call
 * @ref crypt_init_by_name_and_header "crypt_init_by_name_and_header(cd, name, NULL)"
 *
 * @sa crypt_init_by_name_and_header
 */
int crypt_init_by_name(struct crypt_device **cd, const char *name);

/**
 * Release crypt device context and used memory.
 *
 * @param cd crypt device handle
 */
void crypt_free(struct crypt_device *cd);

/**
 * Set confirmation callback (yes/no).
 *
 * If code need confirmation (like resetting uuid or restoring LUKS header from file)
 * this function is called. If not defined, everything is confirmed.
 *
 * Callback function @e confirm should return @e 0 if operation is declined,
 * other values mean accepted.
 *
 * @param cd crypt device handle
 * @param confirm user defined confirm callback reference
 * @param usrptr provided identification in callback
 * @param msg Message for user to confirm
 *
 * @note Current version of cryptsetup API requires confirmation for UUID change and
 *	 LUKS header restore only.
 */
void crypt_set_confirm_callback(struct crypt_device *cd,
	int (*confirm)(const char *msg, void *usrptr),
	void *usrptr);

/**
 * Set data device
 * For LUKS it is encrypted data device when LUKS header is separated.
 * For VERITY it is data device when hash device is separated.
 *
 * @param cd crypt device handle
 * @param device path to device
 *
 */
int crypt_set_data_device(struct crypt_device *cd, const char *device);
/** @} */

/**
 * @defgroup crypt-log Cryptsetup logging
 * Set of functions and defines used in cryptsetup for
 * logging purposes
 * @addtogroup crypt-log
 * @{
 */

/** normal log level */
#define CRYPT_LOG_NORMAL 0
/** error log level */
#define CRYPT_LOG_ERROR  1
/** verbose log level */
#define CRYPT_LOG_VERBOSE  2
/** debug log level - always on stdout */
#define CRYPT_LOG_DEBUG -1

/**
 * Set log function.
 *
 * @param cd crypt device handle (can be @e NULL to set default log function)
 * @param log user defined log function reference
 * @param usrptr provided identification in callback
 * @param level log level below (debug messages can uses other levels)
 * @param msg log message
 */
void crypt_set_log_callback(struct crypt_device *cd,
	void (*log)(int level, const char *msg, void *usrptr),
	void *usrptr);

/**
 * Defines log function or use the default one otherwise.
 *
 * @see crypt_set_log_callback
 *
 * @param cd crypt device handle
 * @param level log level
 * @param msg log message
 */
void crypt_log(struct crypt_device *cd, int level, const char *msg);
/** @} */

/**
 * @defgroup crypt-set Cryptsetup settings (RNG, PBKDF, locking)
 * @addtogroup crypt-set
 * @{
 */

/** CRYPT_RNG_URANDOM - use /dev/urandom */
#define CRYPT_RNG_URANDOM 0
/** CRYPT_RNG_RANDOM  - use /dev/random (waits if no entropy in system) */
#define CRYPT_RNG_RANDOM  1

/**
 * Set which RNG (random number generator) is used for generating long term key
 *
 * @param cd crypt device handle
 * @param rng_type kernel random number generator to use
 *
 */
void crypt_set_rng_type(struct crypt_device *cd, int rng_type);

/**
 * Get which RNG (random number generator) is used for generating long term key.
 *
 * @param cd crypt device handle
 * @return RNG type on success or negative errno value otherwise.
 *
 */
int crypt_get_rng_type(struct crypt_device *cd);

/**
 * PBKDF parameters.
 */
struct crypt_pbkdf_type {
	const char *type;         /**< PBKDF algorithm  */
	const char *hash;         /**< Hash algorithm */
	uint32_t time_ms;         /**< Requested time cost [milliseconds] */
	uint32_t iterations;      /**< Iterations, 0 or benchmarked value. */
	uint32_t max_memory_kb;   /**< Requested or benchmarked  memory cost [kilobytes] */
	uint32_t parallel_threads;/**< Requested parallel cost [threads] */
	uint32_t flags;           /**< CRYPT_PBKDF* flags */
};

/** Iteration time set by crypt_set_iteration_time(), for compatibility only. */
#define CRYPT_PBKDF_ITER_TIME_SET   (1 << 0)
/** Never run benchmarks, use pre-set value or defaults. */
#define CRYPT_PBKDF_NO_BENCHMARK    (1 << 1)

/** PBKDF2 according to RFC2898, LUKS1 legacy */
#define CRYPT_KDF_PBKDF2   "pbkdf2"
/** Argon2i according to RFC */
#define CRYPT_KDF_ARGON2I  "argon2i"
/** Argon2id according to RFC */
#define CRYPT_KDF_ARGON2ID "argon2id"

/**
 * Set default PBKDF (Password-Based Key Derivation Algorithm) for next keyslot
 * about to get created with any crypt_keyslot_add_*() call.
 *
 * @param cd crypt device handle
 * @param pbkdf PBKDF parameters
 *
 * @return 0 on success or negative errno value otherwise.
 *
 * @note For LUKS1, only PBKDF2 is supported, other settings will be rejected.
 * @note For non-LUKS context types the call succeeds, but PBKDF is not used.
 */
int crypt_set_pbkdf_type(struct crypt_device *cd,
	 const struct crypt_pbkdf_type *pbkdf);

/**
 * Get default PBKDF (Password-Based Key Derivation Algorithm) settings for keyslots.
 * Works only with LUKS device handles (both versions).
 *
 * @param type type of device (see @link crypt-type @endlink)
 *
 * @return struct on success or NULL value otherwise.
 *
 */
const struct crypt_pbkdf_type *crypt_get_pbkdf_default(const char *type);

/**
 * Get current PBKDF (Password-Based Key Derivation Algorithm) settings for keyslots.
 * Works only with LUKS device handles (both versions).
 *
 * @param cd crypt device handle
 *
 * @return struct on success or NULL value otherwise.
 *
 */
const struct crypt_pbkdf_type *crypt_get_pbkdf_type(struct crypt_device *cd);

/**
 * Set how long should cryptsetup iterate in PBKDF2 function.
 * Default value heads towards the iterations which takes around 1 second.
 * \b Deprecated, only for backward compatibility.
 * Use @link crypt_set_pbkdf_type @endlink.
 *
 * @param cd crypt device handle
 * @param iteration_time_ms the time in ms
 *
 * @note If the time value is not acceptable for active PBKDF, value is quietly ignored.
 */
void crypt_set_iteration_time(struct crypt_device *cd, uint64_t iteration_time_ms);

/**
 * Helper to lock/unlock memory to avoid swap sensitive data to disk.
 *
 * @param cd crypt device handle, can be @e NULL
 * @param lock 0 to unlock otherwise lock memory
 *
 * @returns Value indicating whether the memory is locked (function can be called multiple times).
 *
 * @note Only root can do this.
 * @note It locks/unlocks all process memory, not only crypt context.
 */
int crypt_memory_lock(struct crypt_device *cd, int lock);

/**
 * Set global lock protection for on-disk metadata (file-based locking).
 *
 * @param cd crypt device handle, can be @e NULL
 * @param enable 0 to disable locking otherwise enable it (default)
 *
 * @returns @e 0 on success or negative errno value otherwise.
 *
 * @note Locking applied only for some metadata formats (LUKS2).
 * @note The switch is global on the library level.
 * 	 In current version locking can be only switched off and cannot be switched on later.
 */
int crypt_metadata_locking(struct crypt_device *cd, int enable);
/** @} */

/**
 * @defgroup crypt-type Cryptsetup on-disk format types
 * Set of functions, \#defines and structs related
 * to on-disk format types
 * @addtogroup crypt-type
 * @{
 */

/** plain crypt device, no on-disk header */
#define CRYPT_PLAIN "PLAIN"
/** LUKS version 1 header on-disk */
#define CRYPT_LUKS1 "LUKS1"
/** LUKS version 2 header on-disk */
#define CRYPT_LUKS2 "LUKS2"
/** loop-AES compatibility mode */
#define CRYPT_LOOPAES "LOOPAES"
/** dm-verity mode */
#define CRYPT_VERITY "VERITY"
/** TCRYPT (TrueCrypt-compatible and VeraCrypt-compatible) mode */
#define CRYPT_TCRYPT "TCRYPT"
/** INTEGRITY dm-integrity device */
#define CRYPT_INTEGRITY "INTEGRITY"

/** LUKS any version */
#define CRYPT_LUKS NULL

/**
 * Get device type
 *
 * @param cd crypt device handle
 * @return string according to device type or @e NULL if not known.
 */
const char *crypt_get_type(struct crypt_device *cd);

/**
 *
 * Structure used as parameter for PLAIN device type.
 *
 * @see crypt_format
 */
struct crypt_params_plain {
	const char *hash;     /**< password hash function */
	uint64_t offset;      /**< offset in sectors */
	uint64_t skip;        /**< IV offset / initialization sector */
	uint64_t size;        /**< size of mapped device or @e 0 for autodetection */
	uint32_t sector_size; /**< sector size in bytes (@e 0 means 512 for compatibility) */
};

/**
 * Structure used as parameter for LUKS device type.
 *
 * @see crypt_format, crypt_load
 *
 * @note during crypt_format @e data_device attribute determines
 * 	 if the LUKS header is separated from encrypted payload device
 *
 */
struct crypt_params_luks1 {
	const char *hash;        /**< hash used in LUKS header */
	size_t data_alignment;   /**< data alignment in sectors, data offset is multiple of this */
	const char *data_device; /**< detached encrypted data device or @e NULL */
};

/**
 *
 * Structure used as parameter for loop-AES device type.
 *
 * @see crypt_format
 *
 */
struct crypt_params_loopaes {
	const char *hash; /**< key hash function */
	uint64_t offset;  /**< offset in sectors */
	uint64_t skip;    /**< IV offset / initialization sector */
};

/**
 *
 * Structure used as parameter for dm-verity device type.
 *
 * @see crypt_format, crypt_load
 *
 */
struct crypt_params_verity {
	const char *hash_name;     /**< hash function */
	const char *data_device;   /**< data_device (CRYPT_VERITY_CREATE_HASH) */
	const char *hash_device;   /**< hash_device (output only) */
	const char *fec_device;    /**< fec_device (output only) */
	const char *salt;          /**< salt */
	uint32_t salt_size;        /**< salt size (in bytes) */
	uint32_t hash_type;        /**< in-kernel hashing type */
	uint32_t data_block_size;  /**< data block size (in bytes) */
	uint32_t hash_block_size;  /**< hash block size (in bytes) */
	uint64_t data_size;        /**< data area size (in data blocks) */
	uint64_t hash_area_offset; /**< hash/header offset (in bytes) */
	uint64_t fec_area_offset;  /**< FEC/header offset (in bytes) */
	uint32_t fec_roots;        /**< Reed-Solomon FEC roots */
	uint32_t flags;            /**< CRYPT_VERITY* flags */
};

/** No on-disk header (only hashes) */
#define CRYPT_VERITY_NO_HEADER   (1 << 0)
/** Verity hash in userspace before activation */
#define CRYPT_VERITY_CHECK_HASH  (1 << 1)
/** Create hash - format hash device */
#define CRYPT_VERITY_CREATE_HASH (1 << 2)

/**
 *
 * Structure used as parameter for TCRYPT device type.
 *
 * @see crypt_load
 *
 */
struct crypt_params_tcrypt {
	const char *passphrase;    /**< passphrase to unlock header (input only) */
	size_t passphrase_size;    /**< passphrase size (input only, max length is 64) */
	const char **keyfiles;     /**< keyfile paths to unlock header (input only) */
	unsigned int keyfiles_count;/**< keyfiles count (input only) */
	const char *hash_name;     /**< hash function for PBKDF */
	const char *cipher;        /**< cipher chain c1[-c2[-c3]] */
	const char *mode;          /**< cipher block mode */
	size_t key_size;           /**< key size in bytes (the whole chain) */
	uint32_t flags;            /**< CRYPT_TCRYPT* flags */
	uint32_t veracrypt_pim;    /**< VeraCrypt Personal Iteration Multiplier */
};

/** Include legacy modes when scanning for header */
#define CRYPT_TCRYPT_LEGACY_MODES    (1 << 0)
/** Try to load hidden header (describing hidden device) */
#define CRYPT_TCRYPT_HIDDEN_HEADER   (1 << 1)
/** Try to load backup header */
#define CRYPT_TCRYPT_BACKUP_HEADER   (1 << 2)
/** Device contains encrypted system (with boot loader) */
#define CRYPT_TCRYPT_SYSTEM_HEADER   (1 << 3)
/** Include VeraCrypt modes when scanning for header,
 *  all other TCRYPT flags applies as well.
 *  VeraCrypt device is reported as TCRYPT type.
 */
#define CRYPT_TCRYPT_VERA_MODES      (1 << 4)

/**
 *
 * Structure used as parameter for dm-integrity device type.
 *
 * @see crypt_format, crypt_load
 *
 */
struct crypt_params_integrity {
	uint64_t journal_size;               /**< size of journal in bytes */
	unsigned int journal_watermark;      /**< journal flush watermark in percents */
	unsigned int journal_commit_time;    /**< journal commit time in ms */
	uint32_t interleave_sectors;         /**< number of interleave sectors (power of two) */
	uint32_t tag_size;                   /**< tag size per-sector in bytes */
	uint32_t sector_size;                /**< sector size in bytes */
	uint32_t buffer_sectors;             /**< number of sectors in one buffer */
	const char *integrity;               /**< integrity algorithm, NULL for LUKS2 */
	uint32_t integrity_key_size;         /**< integrity key size in bytes, info only, 0 for LUKS2 */

	const char *journal_integrity;       /**< journal integrity algorithm */
	const char *journal_integrity_key;   /**< journal integrity key, only for crypt_load */
	uint32_t journal_integrity_key_size; /**< journal integrity key size in bytes, only for crypt_load */

	const char *journal_crypt;           /**< journal encryption algorithm */
	const char *journal_crypt_key;       /**< journal crypt key, only for crypt_load */
	uint32_t journal_crypt_key_size;     /**< journal crypt key size in bytes, only for crypt_load */
};

/**
 * Structure used as parameter for LUKS2 device type.
 *
 * @see crypt_format, crypt_load
 *
 * @note during crypt_format @e data_device attribute determines
 * 	 if the LUKS2 header is separated from encrypted payload device
 *
 */
struct crypt_params_luks2 {
	const struct crypt_pbkdf_type *pbkdf; /**< PBKDF (and hash) parameters or @e NULL*/
	const char *integrity;                /**< integrity algorithm or @e NULL */
	const struct crypt_params_integrity *integrity_params; /**< Data integrity parameters or @e NULL*/
	size_t data_alignment;   /**< data alignment in sectors, data offset is multiple of this */
	const char *data_device; /**< detached encrypted data device or @e NULL */
	uint32_t sector_size;    /**< encryption sector size */
	const char *label;       /**< header label or @e NULL*/
	const char *subsystem;   /**< header subsystem label or @e NULL*/
};
/** @} */

/**
 * @defgroup crypt-actions Cryptsetup device context actions
 * Set of functions for formatting and manipulating with specific crypt_type
 * @addtogroup crypt-actions
 * @{
 */

/**
 * Create (format) new crypt device (and possible header on-disk) but do not activate it.
 *
 * @pre @e cd contains initialized and not formatted device context (device type must @b not be set)
 *
 * @param cd crypt device handle
 * @param type type of device (optional params struct must be of this type)
 * @param cipher (e.g. "aes")
 * @param cipher_mode including IV specification (e.g. "xts-plain")
 * @param uuid requested UUID or @e NULL if it should be generated
 * @param volume_key pre-generated volume key or @e NULL if it should be generated (only for LUKS)
 * @param volume_key_size size of volume key in bytes.
 * @param params crypt type specific parameters (see @link crypt-type @endlink)
 *
 * @returns @e 0 on success or negative errno value otherwise.
 *
 * @note Note that crypt_format does not create LUKS keyslot (any version). To create keyslot
 *	 call any crypt_keyslot_add_* function.
 * @note For VERITY @link crypt-type @endlink, only uuid parameter is used, other parameters
 * 	are ignored and verity specific attributes are set through mandatory params option.
 */
int 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);

/**
 * Convert to new type for already existing device.
 *
 * @param cd crypt device handle
 * @param type type of device (optional params struct must be of this type)
 * @param params crypt type specific parameters (see @link crypt-type @endlink)
 *
 * @returns 0 on success or negative errno value otherwise.
 *
 * @note Currently, only LUKS1->LUKS2 and LUKS2->LUKS1 conversions are supported.
 *	 Not all LUKS2 devices may be converted back to LUKS1. To make such a conversion
 *	 posible all active LUKS2 keyslots must be in LUKS1 compatible mode (i.e. pbkdf
 *	 type must be PBKDF2) and device cannot be formated with any authenticated
 *	 encryption mode.
 *
 * @note Device must be offline for conversion. UUID change is not possible for active
 *	 devices.
 */
int crypt_convert(struct crypt_device *cd,
	const char *type,
	void *params);

/**
 * Set new UUID for already existing device.
 *
 * @param cd crypt device handle
 * @param uuid requested UUID or @e NULL if it should be generated
 *
 * @returns 0 on success or negative errno value otherwise.
 *
 * @note Currently, only LUKS device type are supported
 */
int crypt_set_uuid(struct crypt_device *cd,
	const char *uuid);

/**
 * Set new labels (label and subsystem) for already existing device.
 *
 * @param cd crypt device handle
 * @param label requested label or @e NULL
 * @param subsystem requested subsystem label or @e NULL
 *
 * @returns 0 on success or negative errno value otherwise.
 *
 * @note Currently, only LUKS2 device type is supported
 */
int crypt_set_label(struct crypt_device *cd,
	const char *label,
	const char *subsystem);

/**
 * Enable or disable loading of volume keys via kernel keyring. When set to
 * 'enabled' library loads key in kernel keyring first and pass the key
 * description to dm-crypt instead of binary key copy. If set to 'disabled'
 * library fallbacks to old method of loading volume key directly in
 * dm-crypt target.
 *
 * @param cd crypt device handle, can be @e NULL
 * @param enable 0 to disable loading of volume keys via kernel keyring
 * 	  (classical method) otherwise enable it (default)
 *
 * @returns @e 0 on success or negative errno value otherwise.
 *
 * @note Currently loading of volume keys via kernel keyring is supported
 * 	 (and enabled by default) only for LUKS2 devices.
 * @note The switch is global on the library level.
 */
int crypt_volume_key_keyring(struct crypt_device *cd, int enable);

/**
 * Load crypt device parameters from on-disk header.
 *
 * @param cd crypt device handle
 * @param requested_type @link crypt-type @endlink or @e NULL for all known
 * @param params crypt type specific parameters (see @link crypt-type @endlink)
 *
 * @returns 0 on success or negative errno value otherwise.
 *
 * @post In case LUKS header is read successfully but payload device is too small
 * error is returned and device type in context is set to @e NULL
 *
 * @note Note that in current version load works only for LUKS and VERITY device type.
 *
 */
int crypt_load(struct crypt_device *cd,
	const char *requested_type,
	void *params);

/**
 * Try to repair crypt device LUKS1 on-disk header if invalid.
 *
 * @param cd crypt device handle
 * @param requested_type @link crypt-type @endlink or @e NULL for all known
 * @param params crypt type specific parameters (see @link crypt-type @endlink)
 *
 * @returns 0 on success or negative errno value otherwise.
 *
 * @note Does not support LUKS2 devices explicitly. LUKS2 header is auto-repaired
 *	 (if exactly one header checksum does not match) automatically on
 *	 crypt_load().
 */
int crypt_repair(struct crypt_device *cd,
	const char *requested_type,
	void *params);

/**
 * Resize crypt device.
 *
 * @param cd - crypt device handle
 * @param name - name of device to resize
 * @param new_size - new device size in sectors or @e 0 to use all of the underlying device size
 *
 * @return @e 0 on success or negative errno value otherwise.
 *
 * @note Most notably it returns -EPERM when device was activated with volume key
 * 	 in kernel keyring and current device handle (context) doesn't have verified key
 * 	 loaded in kernel. To load volume key for already active device use any of
 * 	 @link crypt_activate_by_passphrase @endlink, @link crypt_activate_by_keyfile @endlink,
 * 	 @link crypt_activate_by_keyfile_offset @endlink, @link crypt_activate_by_volume_key @endlink,
 * 	 @link crypt_activate_by_keyring @endlink or @link crypt_activate_by_token @endlink with flag
 * 	 @e CRYPT_ACTIVATE_KEYRING_KEY raised and @e name parameter set to @e NULL.
 */
int crypt_resize(struct crypt_device *cd,
	const char *name,
	uint64_t new_size);

/**
 * Suspend crypt device.
 *
 * @param cd crypt device handle, can be @e NULL
 * @param name name of device to suspend
 *
 * @return 0 on success or negative errno value otherwise.
 *
 * @note Only LUKS device type is supported
 *
 */
int crypt_suspend(struct crypt_device *cd,
	const char *name);

/**
 * Resume crypt device using passphrase.
 *
 *
 * @param cd crypt device handle
 * @param name name of device to resume
 * @param keyslot requested keyslot or CRYPT_ANY_SLOT
 * @param passphrase passphrase used to unlock volume key
 * @param passphrase_size size of @e passphrase (binary data)
 *
 * @return unlocked key slot number or negative errno otherwise.
 *
 * @note Only LUKS device type is supported
 */
int crypt_resume_by_passphrase(struct crypt_device *cd,
	const char *name,
	int keyslot,
	const char *passphrase,
	size_t passphrase_size);

/**
 * Resume crypt device using key file.
 *
 * @param cd crypt device handle
 * @param name name of device to resume
 * @param keyslot requested keyslot or CRYPT_ANY_SLOT
 * @param keyfile key file used to unlock volume key
 * @param keyfile_size number of bytes to read from keyfile, 0 is unlimited
 * @param keyfile_offset number of bytes to skip at start of keyfile
 *
 * @return unlocked key slot number or negative errno otherwise.
 */
int crypt_resume_by_keyfile_device_offset(struct crypt_device *cd,
	const char *name,
	int keyslot,
	const char *keyfile,
	size_t keyfile_size,
	uint64_t keyfile_offset);

/**
 * Backward compatible crypt_resume_by_keyfile_device_offset() (with size_t offset).
 */
int crypt_resume_by_keyfile_offset(struct crypt_device *cd,
	const char *name,
	int keyslot,
	const char *keyfile,
	size_t keyfile_size,
	size_t keyfile_offset);

/**
 * Backward compatible crypt_resume_by_keyfile_device_offset() (without offset).
 */
int crypt_resume_by_keyfile(struct crypt_device *cd,
	const char *name,
	int keyslot,
	const char *keyfile,
	size_t keyfile_size);
/** @} */

/**
 * @defgroup crypt-keyslot LUKS keyslots
 * @addtogroup crypt-keyslot
 * @{
 */

/** iterate through all keyslots and find first one that fits */
#define CRYPT_ANY_SLOT -1

/**
 * Add key slot using provided passphrase.
 *
 * @pre @e cd contains initialized and formatted LUKS device context
 *
 * @param cd crypt device handle
 * @param keyslot requested keyslot or @e CRYPT_ANY_SLOT
 * @param passphrase passphrase used to unlock volume key
 * @param passphrase_size size of passphrase (binary data)
 * @param new_passphrase passphrase for new keyslot
 * @param new_passphrase_size size of @e new_passphrase (binary data)
 *
 * @return allocated key slot number or negative errno otherwise.
 */
int crypt_keyslot_add_by_passphrase(struct crypt_device *cd,
	int keyslot,
	const char *passphrase,
	size_t passphrase_size,
	const char *new_passphrase,
	size_t new_passphrase_size);

/**
 * Change defined key slot using provided passphrase.
 *
 * @pre @e cd contains initialized and formatted LUKS device context
 *
 * @param cd crypt device handle
 * @param keyslot_old old keyslot or @e CRYPT_ANY_SLOT
 * @param keyslot_new new keyslot (can be the same as old)
 * @param passphrase passphrase used to unlock volume key
 * @param passphrase_size size of passphrase (binary data)
 * @param new_passphrase passphrase for new keyslot
 * @param new_passphrase_size size of @e new_passphrase (binary data)
 *
 * @return allocated key slot number or negative errno otherwise.
 *
 * @note This function is just internal implementation of luksChange
 * command to avoid reading of volume key outside libcryptsetup boundary
 * in FIPS mode.
 */
int crypt_keyslot_change_by_passphrase(struct crypt_device *cd,
	int keyslot_old,
	int keyslot_new,
	const char *passphrase,
	size_t passphrase_size,
	const char *new_passphrase,
	size_t new_passphrase_size);

/**
* Add key slot using provided key file path.
 *
 * @pre @e cd contains initialized and formatted LUKS device context
 *
 * @param cd crypt device handle
 * @param keyslot requested keyslot or @e CRYPT_ANY_SLOT
 * @param keyfile key file used to unlock volume key
 * @param keyfile_size number of bytes to read from keyfile, @e 0 is unlimited
 * @param keyfile_offset number of bytes to skip at start of keyfile
 * @param new_keyfile keyfile for new keyslot
 * @param new_keyfile_size number of bytes to read from @e new_keyfile, @e 0 is unlimited
 * @param new_keyfile_offset number of bytes to skip at start of new_keyfile
 *
 * @return allocated key slot number or negative errno otherwise.
 */
int crypt_keyslot_add_by_keyfile_device_offset(struct crypt_device *cd,
	int keyslot,
	const char *keyfile,
	size_t keyfile_size,
	uint64_t keyfile_offset,
	const char *new_keyfile,
	size_t new_keyfile_size,
	uint64_t new_keyfile_offset);

/**
 * Backward compatible crypt_keyslot_add_by_keyfile_device_offset() (with size_t offset).
 */
int crypt_keyslot_add_by_keyfile_offset(struct crypt_device *cd,
	int keyslot,
	const char *keyfile,
	size_t keyfile_size,
	size_t keyfile_offset,
	const char *new_keyfile,
	size_t new_keyfile_size,
	size_t new_keyfile_offset);

/**
 * Backward compatible crypt_keyslot_add_by_keyfile_device_offset() (without offset).
 */
int crypt_keyslot_add_by_keyfile(struct crypt_device *cd,
	int keyslot,
	const char *keyfile,
	size_t keyfile_size,
	const char *new_keyfile,
	size_t new_keyfile_size);

/**
 * Add key slot using provided volume key.
 *
 * @pre @e cd contains initialized and formatted LUKS device context
 *
 * @param cd crypt device handle
 * @param keyslot requested keyslot or CRYPT_ANY_SLOT
 * @param volume_key provided volume key or @e NULL if used after crypt_format
 * @param volume_key_size size of volume_key
 * @param passphrase passphrase for new keyslot
 * @param passphrase_size size of passphrase
 *
 * @return allocated key slot number or negative errno otherwise.
 */
int 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);

/** create keyslot with volume key not associated with current dm-crypt segment */
#define CRYPT_VOLUME_KEY_NO_SEGMENT (1 << 0)

/** create keyslot with new volume key and assign it to current dm-crypt segment */
#define CRYPT_VOLUME_KEY_SET (1 << 1)

/**
 * Add key slot using provided key.
 *
 * @pre @e cd contains initialized and formatted LUKS2 device context
 *
 * @param cd crypt device handle
 * @param keyslot requested keyslot or CRYPT_ANY_SLOT
 * @param volume_key provided volume key or @e NULL (see note below)
 * @param volume_key_size size of volume_key
 * @param passphrase passphrase for new keyslot
 * @param passphrase_size size of passphrase
 * @param flags key flags to set
 *
 * @return allocated key slot number or negative errno otherwise.
 *
 * @note in case volume_key is @e NULL following first matching rule will apply:
 * @li if cd is device handle used in crypt_format() by current process, the volume
 *     key generated (or passed) in crypt_format() will be stored in keyslot.
 * @li if CRYPT_VOLUME_KEY_NO_SEGMENT flag is raised the new volume_key will be
 *     generated and stored in keyslot. The keyslot will become unbound (unusable to
 *     dm-crypt device activation).
 * @li fails with -EINVAL otherwise
 *
 * @warning CRYPT_VOLUME_KEY_SET flag force updates volume key. It is @b not @b reencryption!
 * 	    By doing so you will most probably destroy your ciphertext data device. It's supposed
 * 	    to be used only in wrapped keys scheme for key refresh process where real (inner) volume
 * 	    key stays untouched. It may be involed on active @e keyslot which makes the (previously
 * 	    unbound) keyslot new regular keyslot.
 */
int crypt_keyslot_add_by_key(struct crypt_device *cd,
	int keyslot,
	const char *volume_key,
	size_t volume_key_size,
	const char *passphrase,
	size_t passphrase_size,
	uint32_t flags);

/**
 * Destroy (and disable) key slot.
 *
 * @pre @e cd contains initialized and formatted LUKS device context
 *
 * @param cd crypt device handle
 * @param keyslot requested key slot to destroy
 *
 * @return @e 0 on success or negative errno value otherwise.
 *
 * @note Note that there is no passphrase verification used.
 */
int crypt_keyslot_destroy(struct crypt_device *cd, int keyslot);
/** @} */

/**
 * @defgroup crypt-aflags Device runtime attributes
 * Activation flags
 * @addtogroup crypt-aflags
 * @{
 */

/** device is read only */
#define CRYPT_ACTIVATE_READONLY (1 << 0)
/** only reported for device without uuid */
#define CRYPT_ACTIVATE_NO_UUID  (1 << 1)
/** activate even if cannot grant exclusive access (DANGEROUS) */
#define CRYPT_ACTIVATE_SHARED   (1 << 2)
/** enable discards aka TRIM */
#define CRYPT_ACTIVATE_ALLOW_DISCARDS (1 << 3)
/** skip global udev rules in activation ("private device"), input only */
#define CRYPT_ACTIVATE_PRIVATE (1 << 4)
/** corruption detected (verity), output only */
#define CRYPT_ACTIVATE_CORRUPTED (1 << 5)
/** use same_cpu_crypt option for dm-crypt */
#define CRYPT_ACTIVATE_SAME_CPU_CRYPT (1 << 6)
/** use submit_from_crypt_cpus for dm-crypt */
#define CRYPT_ACTIVATE_SUBMIT_FROM_CRYPT_CPUS (1 << 7)
/** dm-verity: ignore_corruption flag - ignore corruption, log it only */
#define CRYPT_ACTIVATE_IGNORE_CORRUPTION (1 << 8)
/** dm-verity: restart_on_corruption flag - restart kernel on corruption */
#define CRYPT_ACTIVATE_RESTART_ON_CORRUPTION (1 << 9)
/** dm-verity: ignore_zero_blocks - do not verify zero blocks */
#define CRYPT_ACTIVATE_IGNORE_ZERO_BLOCKS (1 << 10)
/** key loaded in kernel keyring instead directly in dm-crypt */
#define CRYPT_ACTIVATE_KEYRING_KEY (1 << 11)
/** dm-integrity: direct writes, do not use journal */
#define CRYPT_ACTIVATE_NO_JOURNAL (1 << 12)
/** dm-integrity: recovery mode - no journal, no integrity checks */
#define CRYPT_ACTIVATE_RECOVERY (1 << 13)
/** ignore persistently stored flags */
#define CRYPT_ACTIVATE_IGNORE_PERSISTENT (1 << 14)
/** dm-verity: check_at_most_once - check data blocks only the first time */
#define CRYPT_ACTIVATE_CHECK_AT_MOST_ONCE (1 << 15)

/**
 * Active device runtime attributes
 */
struct crypt_active_device {
	uint64_t offset;    /**< offset in sectors */
	uint64_t iv_offset; /**< IV initialization sector */
	uint64_t size;      /**< active device size */
	uint32_t flags;     /**< activation flags */
};

/**
 * Receive runtime attributes of active crypt device.
 *
 * @param cd crypt device handle (can be @e NULL)
 * @param name name of active device
 * @param cad preallocated active device attributes to fill
 *
 * @return @e 0 on success or negative errno value otherwise
 *
 */
int crypt_get_active_device(struct crypt_device *cd,
			    const char *name,
			    struct crypt_active_device *cad);
/** @} */

/**
 * @defgroup crypt-pflags LUKS2 Device persistent flags and requirements
 * @addtogroup crypt-pflags
 * @{
 */

/**
 * LUKS2 header requirements
 */
/** Unfinished offline reencryption */
#define CRYPT_REQUIREMENT_OFFLINE_REENCRYPT	(1 << 0)
/** unknown requirement in header (output only) */
#define CRYPT_REQUIREMENT_UNKNOWN		(1 << 31)

/**
 * Persistent flags type
 */
typedef enum {
	CRYPT_FLAGS_ACTIVATION, /**< activation flags, @see aflags */
	CRYPT_FLAGS_REQUIREMENTS /**< requirements flags */
} crypt_flags_type;

/**
 * Set persistent flags.
 *
 * @param cd crypt device handle (can be @e NULL)
 * @param type type to set (CRYPT_FLAGS_ACTIVATION or CRYPT_FLAGS_REQUIREMENTS)
 * @param flags flags to set
 *
 * @return @e 0 on success or negative errno value otherwise
 *
 * @note Valid only for LUKS2.
 *
 * @note Not all activation flags can be stored. Only ALLOW_DISCARD,
 * 	 SAME_CPU_CRYPT, SUBMIT_FROM_CRYPT_CPU and NO_JOURNAL can be
 * 	 stored persistently.
 *
 * @note Only requirements flags recognised by current library may be set.
 *	 CRYPT_REQUIREMENT_FLAG is illegal (output only) in set operation.
 */
int crypt_persistent_flags_set(struct crypt_device *cd,
	crypt_flags_type type,
	uint32_t flags);

/**
 * Get persistent flags stored in header.
 *
 * @param cd crypt device handle (can be @e NULL)
 * @param type flags type to retrieve (CRYPT_FLAGS_ACTIVATION or CRYPT_FLAGS_REQUIREMENTS)
 * @param flags reference to output variable
 *
 * @return @e 0 on success or negative errno value otherwise
 */
int crypt_persistent_flags_get(struct crypt_device *cd,
	crypt_flags_type type,
	uint32_t *flags);
/** @} */

/**
 * @defgroup crypt-activation Device activation
 * @addtogroup crypt-activation
 * @{
 */

/**
 * Activate device or check passphrase.
 *
 * @param cd crypt device handle
 * @param name name of device to create, if @e NULL only check passphrase
 * @param keyslot requested keyslot to check or @e CRYPT_ANY_SLOT
 * @param passphrase passphrase used to unlock volume key
 * @param passphrase_size size of @e passphrase
 * @param flags activation flags
 *
 * @return unlocked key slot number or negative errno otherwise.
 */
int crypt_activate_by_passphrase(struct crypt_device *cd,
	const char *name,
	int keyslot,
	const char *passphrase,
	size_t passphrase_size,
	uint32_t flags);

/**
 * Activate device or check using key file.
 *
 * @param cd crypt device handle
 * @param name name of device to create, if @e NULL only check keyfile
 * @param keyslot requested keyslot to check or CRYPT_ANY_SLOT
 * @param keyfile key file used to unlock volume key
 * @param keyfile_size number of bytes to read from keyfile, 0 is unlimited
 * @param keyfile_offset number of bytes to skip at start of keyfile
 * @param flags activation flags
 *
 * @return unlocked key slot number or negative errno otherwise.
 */
int crypt_activate_by_keyfile_device_offset(struct crypt_device *cd,
	const char *name,
	int keyslot,
	const char *keyfile,
	size_t keyfile_size,
	uint64_t keyfile_offset,
	uint32_t flags);

/**
 * Backward compatible crypt_activate_by_keyfile_device_offset() (with size_t offset).
 */
int crypt_activate_by_keyfile_offset(struct crypt_device *cd,
	const char *name,
	int keyslot,
	const char *keyfile,
	size_t keyfile_size,
	size_t keyfile_offset,
	uint32_t flags);

/**
 * Backward compatible crypt_activate_by_keyfile_device_offset() (without offset).
 */
int crypt_activate_by_keyfile(struct crypt_device *cd,
	const char *name,
	int keyslot,
	const char *keyfile,
	size_t keyfile_size,
	uint32_t flags);

/**
 * Activate device using provided volume key.
 *
 * @param cd crypt device handle
 * @param name name of device to create, if @e NULL only check volume key
 * @param volume_key provided volume key (or @e NULL to use internal)
 * @param volume_key_size size of volume_key
 * @param flags activation flags
 *
 * @return @e 0 on success or negative errno value otherwise.
 *
 * @note If @e NULL is used for volume_key, device has to be initialized
 * 	 by previous operation (like @ref crypt_format
 * 	 or @ref crypt_init_by_name)
 * @note For VERITY the volume key means root hash required for activation.
 * 	 Because kernel dm-verity is always read only, you have to provide
 * 	 CRYPT_ACTIVATE_READONLY flag always.
 * @note For TCRYPT the volume key should be always NULL and because master
 * 	 key from decrypted header is used instead.
 */
int crypt_activate_by_volume_key(struct crypt_device *cd,
	const char *name,
	const char *volume_key,
	size_t volume_key_size,
	uint32_t flags);

/**
 * Activate device using passphrase stored in kernel keyring.
 *
 * @param cd crypt device handle
 * @param name name of device to create, if @e NULL only check passphrase in keyring
 * @param key_description kernel keyring key description library should look
 *        for passphrase in
 * @param keyslot requested keyslot to check or CRYPT_ANY_SLOT
 * @param flags activation flags
 *
 * @return @e unlocked keyslot number on success or negative errno value otherwise.
 *
 * @note Keyslot passphrase must be stored in 'user' key type
 * 	 and the key has to be reachable for process context
 * 	 on behalf of which this function is called.
 */
int crypt_activate_by_keyring(struct crypt_device *cd,
	const char *name,
	const char *key_description,
	int keyslot,
	uint32_t flags);

/** lazy deactivation - remove once last user releases it */
#define CRYPT_DEACTIVATE_DEFERRED (1 << 0)
/** force deactivation - if the device is busy, it is replaced by error device */
#define CRYPT_DEACTIVATE_FORCE    (1 << 1)

/**
 * Deactivate crypt device. This function tries to remove active device-mapper
 * mapping from kernel. Also, sensitive data like the volume key are removed from
 * memory
 *
 * @param cd crypt device handle, can be @e NULL
 * @param name name of device to deactivate
 * @param flags deactivation flags
 *
 * @return @e 0 on success or negative errno value otherwise.
 *
 */
int crypt_deactivate_by_name(struct crypt_device *cd,
	const char *name,
	uint32_t flags);

/**
 * Deactivate crypt device. See @ref crypt_deactivate_by_name with empty @e flags.
 */
int crypt_deactivate(struct crypt_device *cd, const char *name);
/** @} */

/**
 * @defgroup crypt-key Volume Key manipulation
 * @addtogroup crypt-key
 * @{
 */

/**
 * Get volume key from crypt device.
 *
 * @param cd crypt device handle
 * @param keyslot use this keyslot or @e CRYPT_ANY_SLOT
 * @param volume_key buffer for volume key
 * @param volume_key_size on input, size of buffer @e volume_key,
 *        on output size of @e volume_key
 * @param passphrase passphrase used to unlock volume key
 * @param passphrase_size size of @e passphrase
 *
 * @return unlocked key slot number or negative errno otherwise.
 *
 * @note For TCRYPT cipher chain is the volume key concatenated
 * 	 for all ciphers in chain.
 */
int 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);

/**
 * Verify that provided volume key is valid for crypt device.
 *
 * @param cd crypt device handle
 * @param volume_key provided volume key
 * @param volume_key_size size of @e volume_key
 *
 * @return @e 0 on success or negative errno value otherwise.
 */
int crypt_volume_key_verify(struct crypt_device *cd,
	const char *volume_key,
	size_t volume_key_size);
/** @} */

/**
 * @defgroup crypt-devstat Crypt and Verity device status
 * @addtogroup crypt-devstat
 * @{
 */

/**
 * Device status
 */
typedef enum {
	CRYPT_INVALID,  /**< device mapping is invalid in this context */
	CRYPT_INACTIVE, /**< no such mapped device */
	CRYPT_ACTIVE,   /**< device is active */
	CRYPT_BUSY      /**< device is active and has open count > 0 */
} crypt_status_info;

/**
 * Get status info about device name.
 *
 * @param cd crypt device handle, can be @e NULL
 * @param name crypt device name
 *
 * @return value defined by crypt_status_info.
 *
 */
crypt_status_info crypt_status(struct crypt_device *cd, const char *name);

/**
 * Dump text-formatted information about crypt or verity device to log output.
 *
 * @param cd crypt device handle
 *
 * @return @e 0 on success or negative errno value otherwise.
 */
int crypt_dump(struct crypt_device *cd);

/**
 * Get cipher used in device.
 *
 * @param cd crypt device handle
 *
 * @return used cipher, e.g. "aes" or @e NULL otherwise
 *
 */
const char *crypt_get_cipher(struct crypt_device *cd);

/**
 * Get cipher mode used in device.
 *
 * @param cd crypt device handle
 *
 * @return used cipher mode e.g. "xts-plain" or @e otherwise
 *
 */
const char *crypt_get_cipher_mode(struct crypt_device *cd);

/**
 * Get device UUID.
 *
 * @param cd crypt device handle
 *
 * @return device UUID or @e NULL if not set
 *
 */
const char *crypt_get_uuid(struct crypt_device *cd);

/**
 * Get path to underlaying device.
 *
 * @param cd crypt device handle
 *
 * @return path to underlaying device name
 *
 */
const char *crypt_get_device_name(struct crypt_device *cd);

/**
 * Get device offset in 512-bytes sectors where real data starts (on underlying device).
 *
 * @param cd crypt device handle
 *
 * @return device offset in sectors
 *
 */
uint64_t crypt_get_data_offset(struct crypt_device *cd);

/**
 * Get IV offset in 512-bytes sectors (skip).
 *
 * @param cd crypt device handle
 *
 * @return IV offset
 *
 */
uint64_t crypt_get_iv_offset(struct crypt_device *cd);

/**
 * Get size (in bytes) of volume key for crypt device.
 *
 * @param cd crypt device handle
 *
 * @return volume key size
 *
 */
int crypt_get_volume_key_size(struct crypt_device *cd);

/**
 * Get size (in bytes) of encryption sector for crypt device.
 *
 * @param cd crypt device handle
 *
 * @return sector size
 *
 */
int crypt_get_sector_size(struct crypt_device *cd);

/**
 * Get device parameters for VERITY device.
 *
 * @param cd crypt device handle
 * @param vp verity device info
 *
 * @e 0 on success or negative errno value otherwise.
 *
 */
int crypt_get_verity_info(struct crypt_device *cd,
	struct crypt_params_verity *vp);

/**
 * Get device parameters for INTEGRITY device.
 *
 * @param cd crypt device handle
 * @param ip verity device info
 *
 * @e 0 on success or negative errno value otherwise.
 *
 */
int crypt_get_integrity_info(struct crypt_device *cd,
	struct crypt_params_integrity *ip);
/** @} */

/**
 * @defgroup crypt-benchmark Benchmarking
 * Benchmarking of algorithms
 * @addtogroup crypt-benchmark
 * @{
 */

/**
 * Informational benchmark for ciphers.
 *
 * @param cd crypt device handle
 * @param cipher (e.g. "aes")
 * @param cipher_mode (e.g. "xts"), IV generator is ignored
 * @param volume_key_size size of volume key in bytes
 * @param iv_size size of IV in bytes
 * @param buffer_size size of encryption buffer in bytes used in test
 * @param encryption_mbs measured encryption speed in MiB/s
 * @param decryption_mbs measured decryption speed in MiB/s
 *
 * @return @e 0 on success or negative errno value otherwise.
 *
 * @note If encryption_buffer_size is too small and encryption time
 *       cannot be properly measured, -ERANGE is returned.
 */
int crypt_benchmark(struct crypt_device *cd,
	const char *cipher,
	const char *cipher_mode,
	size_t volume_key_size,
	size_t iv_size,
	size_t buffer_size,
	double *encryption_mbs,
	double *decryption_mbs);

/**
 * Informational benchmark for PBKDF.
 *
 * @param cd crypt device handle
 * @param pbkdf PBKDF parameters
 * @param password password for benchmark
 * @param password_size size of password
 * @param salt salt for benchmark
 * @param salt_size size of salt
 * @param volume_key_size output volume key size
 * @param progress callback function
 * @param usrptr provided identification in callback
 *
 * @return @e 0 on success or negative errno value otherwise.
 */
int crypt_benchmark_pbkdf(struct crypt_device *cd,
	struct crypt_pbkdf_type *pbkdf,
	const char *password,
	size_t password_size,
	const char *salt,
	size_t salt_size,
	size_t volume_key_size,
	int (*progress)(uint32_t time_ms, void *usrptr),
	void *usrptr);
/** @} */

/**
 * @addtogroup crypt-keyslot
 * @{
 */

/**
 * Crypt keyslot info
 */
typedef enum {
	CRYPT_SLOT_INVALID,    /**< invalid keyslot */
	CRYPT_SLOT_INACTIVE,   /**< keyslot is inactive (free) */
	CRYPT_SLOT_ACTIVE,     /**< keyslot is active (used) */
	CRYPT_SLOT_ACTIVE_LAST /**< keylost is active (used)
				 *  and last used at the same time */
} crypt_keyslot_info;

/**
 * Get information about particular key slot.
 *
 * @param cd crypt device handle
 * @param keyslot requested keyslot to check or CRYPT_ANY_SLOT
 *
 * @return value defined by crypt_keyslot_info
 *
 */
crypt_keyslot_info crypt_keyslot_status(struct crypt_device *cd, int keyslot);

/**
 * Crypt keyslot priority
 */
typedef enum {
	CRYPT_SLOT_PRIORITY_INVALID =-1, /**< no such slot */
	CRYPT_SLOT_PRIORITY_IGNORE  = 0, /**< CRYPT_ANY_SLOT will ignore it for open */
	CRYPT_SLOT_PRIORITY_NORMAL  = 1, /**< default priority, tried after preferred */
	CRYPT_SLOT_PRIORITY_PREFER  = 2, /**< will try to open first */
} crypt_keyslot_priority;

/**
 * Get keyslot priority (LUKS2)
 *
 * @param cd crypt device handle
 * @param keyslot keyslot number
 *
 * @return value defined by crypt_keyslot_priority
 */
crypt_keyslot_priority crypt_keyslot_get_priority(struct crypt_device *cd, int keyslot);

/**
 * Set keyslot priority (LUKS2)
 *
 * @param cd crypt device handle
 * @param keyslot keyslot number
 * @param priority priority defined in crypt_keyslot_priority
 *
 * @return @e 0 on success or negative errno value otherwise.
 */
int crypt_keyslot_set_priority(struct crypt_device *cd, int keyslot, crypt_keyslot_priority priority);

/**
 * Get number of keyslots supported for device type.
 *
 * @param type crypt device type
 *
 * @return slot count or negative errno otherwise if device
 * doesn't not support keyslots.
 */
int crypt_keyslot_max(const char *type);

/**
 * Get keyslot area pointers (relative to metadata device).
 *
 * @param cd crypt device handle
 * @param keyslot keyslot number
 * @param offset offset on metadata device (in bytes)
 * @param length length of keyslot area (in bytes)
 *
 * @return @e 0 on success or negative errno value otherwise.
 *
 */
int crypt_keyslot_area(struct crypt_device *cd,
	int keyslot,
	uint64_t *offset,
	uint64_t *length);

/**
 * Get directory where mapped crypt devices are created
 *
 * @return the directory path
 */
const char *crypt_get_dir(void);

/** @} */

/**
 * @defgroup crypt-backup Device metadata backup
 * @addtogroup crypt-backup
 * @{
 */
/**
 * Backup header and keyslots to file.
 *
 * @param cd crypt device handle
 * @param requested_type @link crypt-type @endlink or @e NULL for all known
 * @param backup_file file to backup header to
 *
 * @return @e 0 on success or negative errno value otherwise.
 *
 */
int crypt_header_backup(struct crypt_device *cd,
	const char *requested_type,
	const char *backup_file);

/**
 * Restore header and keyslots from backup file.
 *
 * @param cd crypt device handle
 * @param requested_type @link crypt-type @endlink or @e NULL for all known
 * @param backup_file file to restore header from
 *
 * @return @e 0 on success or negative errno value otherwise.
 *
 */
int crypt_header_restore(struct crypt_device *cd,
	const char *requested_type,
	const char *backup_file);
/** @} */

/**
 * @defgroup crypt-dbg Library debug level
 * Set library debug level
 * @addtogroup crypt-dbg
 * @{
 */

/** Debug all */
#define CRYPT_DEBUG_ALL  -1
/** Debug none */
#define CRYPT_DEBUG_NONE  0

/**
 * Set the debug level for library
 *
 * @param level debug level
 *
 */
void crypt_set_debug_level(int level);
/** @} */

/**
 * @defgroup crypt-keyfile Function to read keyfile
 * @addtogroup crypt-keyfile
 * @{
 */

/**
 * Read keyfile
 *
 * @param cd crypt device handle
 * @param keyfile keyfile to read
 * @param key buffer for key
 * @param key_size_read size of read key
 * @param keyfile_offset keyfile offset
 * @param keyfile_size_max maximal size of keyfile to read
 * @param flags keyfile read flags
 *
 * @return @e 0 on success or negative errno value otherwise.
 */
int crypt_keyfile_device_read(struct crypt_device *cd,
	const char *keyfile,
	char **key, size_t *key_size_read,
	uint64_t keyfile_offset,
	size_t keyfile_size_max,
	uint32_t flags);

/**
 * Backward compatible crypt_keyfile_device_read() (with size_t offset).
 */
int crypt_keyfile_read(struct crypt_device *cd,
	const char *keyfile,
	char **key, size_t *key_size_read,
	size_t keyfile_offset,
	size_t keyfile_size_max,
	uint32_t flags);

/** Read key only to the first end of line (\\n). */
#define CRYPT_KEYFILE_STOP_EOL   (1 << 0)
/** @} */

/**
 * @defgroup crypt-wipe Function to wipe device
 * @addtogroup crypt-wipe
 * @{
 */
/**
 * Wipe pattern
 */
typedef enum {
	CRYPT_WIPE_ZERO,           /**< Fill with zeroes */
	CRYPT_WIPE_RANDOM,         /**< Use RNG to fill data */
	CRYPT_WIPE_ENCRYPTED_ZERO, /**< Add encryption and fill with zeroes as plaintext */
	CRYPT_WIPE_SPECIAL,        /**< Compatibility only, do not use (Gutmann method) */
} crypt_wipe_pattern;

/**
 * Wipe/Fill (part of) a device with the selected pattern.
 *
 * @param cd crypt device handle
 * @param dev_path path to device to wipe or @e NULL if data device should be used
 * @param pattern selected wipe pattern
 * @param offset offset on device (in bytes)
 * @param length length of area to be wiped (in bytes)
 * @param wipe_block_size used block for wiping (one step) (in bytes)
 * @param flags wipe flags
 * @param progress callback function called after each @e wipe_block_size or @e NULL
 * @param usrptr provided identification in callback
 *
 * @return @e 0 on success or negative errno value otherwise.
 *
 * @note A @e progress callback can interrupt wipe process by returning non-zero code.
 *
 * @note If the error values is -EIO or -EINTR, some part of the device could
 *       be overwritten. Other error codes (-EINVAL, -ENOMEM) means that no IO was performed.
 */
int crypt_wipe(struct crypt_device *cd,
	const char *dev_path, /* if null, use data device */
	crypt_wipe_pattern pattern,
	uint64_t offset,
	uint64_t length,
	size_t wipe_block_size,
	uint32_t flags,
	int (*progress)(uint64_t size, uint64_t offset, void *usrptr),
	void *usrptr
);

/** Use direct-io */
#define CRYPT_WIPE_NO_DIRECT_IO (1 << 0)
/** @} */

/**
 * @defgroup crypt-tokens LUKS2 token wrapper access
 *
 * Utilities for handling tokens LUKS2
 * Token is a device or a method how to read password for particular keyslot
 * automatically. It can be chunk of data stored on hardware token or
 * just a metadata how to generate the password.
 *
 * @addtogroup crypt-tokens
 * @{
 */

/** Iterate through all tokens */
#define CRYPT_ANY_TOKEN -1

/**
 * Get content of a token definition in JSON format.
 *
 * @param cd crypt device handle
 * @param token token id
 * @param json buffer with JSON
 *
 * @return allocated token id or negative errno otherwise.
 */
int crypt_token_json_get(struct crypt_device *cd,
	int token,
	const char **json);

/**
 * Store content of a token definition in JSON format.
 *
 * @param cd crypt device handle
 * @param token token id or @e CRYPT_ANY_TOKEN to allocate new one
 * @param json buffer with JSON or @e NULL to remove token
 *
 * @return allocated token id or negative errno otherwise.
 *
 * @note The buffer must be in proper JSON format and must contain at least
 *       string "type" with slot type and an array of string names "keyslots".
 *       Keyslots array contains assignments to particular slots and can be empty.
 */
int crypt_token_json_set(struct crypt_device *cd,
	int token,
	const char *json);

/**
 * Token info
 */
typedef enum {
	CRYPT_TOKEN_INVALID,          /**< token is invalid */
	CRYPT_TOKEN_INACTIVE,         /**< token is empty (free) */
	CRYPT_TOKEN_INTERNAL,         /**< active internal token with driver */
	CRYPT_TOKEN_INTERNAL_UNKNOWN, /**< active internal token (reserved name) with missing token driver */
	CRYPT_TOKEN_EXTERNAL,         /**< active external (user defined) token with driver */
	CRYPT_TOKEN_EXTERNAL_UNKNOWN, /**< active external (user defined) token with missing token driver */
} crypt_token_info;

/**
 * Get info for specific token.
 *
 * @param cd crypt device handle
 * @param token existing token id
 * @param type pointer for returned type string
 *
 * @return token status info. For any returned status (besides CRYPT_TOKEN_INVALID
 * 	   and CRYPT_TOKEN_INACTIVE) and if type parameter is not NULL it will
 * 	   contain address of type string.
 *
 * @note if required, create a copy of string referenced in *type before calling next
 * 	 libcryptsetup API function. The reference may become invalid.
 */
crypt_token_info crypt_token_status(struct crypt_device *cd, int token, const char **type);

/**
 * LUKS2 keyring token parameters.
 *
 * @see crypt_token_builtin_set
 *
 */
struct crypt_token_params_luks2_keyring {
	const char *key_description; /**< Reference in keyring */
};

/**
 * Create a new luks2 keyring token.
 *
 * @param cd crypt device handle
 * @param token token id or @e CRYPT_ANY_TOKEN to allocate new one
 * @param params luks2 keyring token params
 *
 * @return allocated token id or negative errno otherwise.
 *
 */
int crypt_token_luks2_keyring_set(struct crypt_device *cd,
	int token,
	const struct crypt_token_params_luks2_keyring *params);

/**
 * Get LUKS2 keyring token params
 *
 * @param cd crypt device handle
 * @param token existing luks2 keyring token id
 * @param params returned luks2 keyring token params
 *
 * @return allocated token id or negative errno otherwise.
 *
 * @note do not call free() on params members. Members are valid only
 * 	 until next libcryptsetup function is called.
 */
int crypt_token_luks2_keyring_get(struct crypt_device *cd,
	int token,
	struct crypt_token_params_luks2_keyring *params);

/**
 * Assign a token to particular keyslot.
 * (There can be more keyslots assigned to one token id.)
 *
 * @param cd crypt device handle
 * @param token token id
 * @param keyslot keyslot to be assigned to token (CRYPT_ANY SLOT
 * 	  assigns all active keyslots to token)
 *
 * @return allocated token id or negative errno otherwise.
 */
int crypt_token_assign_keyslot(struct crypt_device *cd,
	int token,
	int keyslot);

/**
 * Unassign a token from particular keyslot.
 * (There can be more keyslots assigned to one token id.)
 *
 * @param cd crypt device handle
 * @param token token id
 * @param keyslot keyslot to be unassigned from token (CRYPT_ANY SLOT
 * 	  unassigns all active keyslots from token)
 *
 * @return allocated token id or negative errno otherwise.
 */
int crypt_token_unassign_keyslot(struct crypt_device *cd,
	int token,
	int keyslot);

/**
 * Get info about token assignment to particular keyslot.
 *
 * @param cd crypt device handle
 * @param token token id
 * @param keyslot keyslot
 *
 * @return 0 on success (token exists and is assigned to the keyslot),
 *	   -ENOENT if token is not assigned to a keyslot (token, keyslot
 *	   or both may be inactive) or other negative errno otherwise.
 */
int crypt_token_is_assigned(struct crypt_device *cd,
	int token,
	int keyslot);

/**
 * Token handler open function prototype.
 * This function retrieves password from a token and return allocated buffer
 * containing this password. This buffer has to be deallocated by calling
 * free() function and content should be wiped before deallocation.
 *
 * @param cd crypt device handle
 * @param token token id
 * @param buffer returned allocated buffer with password
 * @param buffer_len length of the buffer
 * @param usrptr user data in @link crypt_activate_by_token @endlink
 */
typedef int (*crypt_token_open_func) (
	struct crypt_device *cd,
	int token,
	char **buffer,
	size_t *buffer_len,
	void *usrptr);

/**
 * Token handler buffer free function prototype.
 * This function is used by library to free the buffer with keyslot
 * passphrase when it's no longer needed. If not defined the library
 * overwrites buffer with zeroes and call free().
 *
 * @param buffer the buffer with keyslot passphrase
 * @param buffer_len the buffer length
 */
typedef void (*crypt_token_buffer_free_func) (void *buffer, size_t buffer_len);

/**
 * Token handler validate function prototype.
 * This fuction validates JSON representation of user defined token for additional data
 * specific for its token type. If defined in the handler, it's called
 * during @link crypt_activate_by_token @endlink. It may also be called during
 * @link crypt_token_json_set @endlink when appropriate token handler was registered before
 * with @link crypt_token_register @endlink.
 *
 * @param cd crypt device handle
 * @param json buffer with JSON
 */
typedef int (*crypt_token_validate_func) (struct crypt_device *cd, const char *json);

/**
 * Token handler dump function prototype.
 * This fuction is supposed to print token implementation specific details. It gets
 * called during @link crypt_dump @endlink if token handler was registered before.
 *
 * @param cd crypt device handle
 * @param json buffer with token JSON
 *
 * @note dump implementations are advised to use @link crypt_log @endlink function
 *	 to dump token details.
 */
typedef void (*crypt_token_dump_func) (struct crypt_device *cd, const char *json);

/**
 * Token handler
 */
typedef struct  {
	const char *name;           /**< token handler name */
	crypt_token_open_func open; /**< token handler open function */
	crypt_token_buffer_free_func buffer_free; /**< token handler buffer_free function (optional) */
	crypt_token_validate_func validate; /**< token handler validate function (optional) */
	crypt_token_dump_func dump; /**< token handler dump function (optional) */
} crypt_token_handler;

/**
 * Register token handler
 *
 * @param handler token handler to register
 *
 * @return @e 0 on success or negative errno value otherwise.
 */
int crypt_token_register(const crypt_token_handler *handler);

/**
 * Activate device or check key using a token.
 *
 * @param cd crypt device handle
 * @param name name of device to create, if @e NULL only check token
 * @param token requested token to check or CRYPT_ANY_TOKEN to check all
 * @param usrptr provided identification in callback
 * @param flags activation flags
 *
 * @return unlocked key slot number or negative errno otherwise.
 */
int crypt_activate_by_token(struct crypt_device *cd,
	const char *name,
	int token,
	void *usrptr,
	uint32_t flags);
/** @} */

#ifdef __cplusplus
}
#endif
#endif /* _LIBCRYPTSETUP_H */