-#include <inttypes.h>
-#include <libcryptsetup.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/types.h>
-#include <unistd.h>
-
-#include "crypt_examples.h"
-
-#define KEY_SIZE 32
-#define EX_DEV_NAME "ex_crypt_dev"
-#define DMDIR "/dev/mapper/"
-#define SECTOR_SIZE 512
-
/*
- * You can use this example with command line parameters as follows,
- * but please note, that this example will not do any sophisticated parameters
- * checking at all.
+ * libcryptsetup API - using LUKS device example
+ *
+ * Copyright (C) 2011-2021 Red Hat, Inc. All rights reserved.
*
- * ./crypt_luks_usage <path>
+ * This file is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
*
- * where:
- * <path> is either regular file or block device. DO NOT use your physical HDD
- * with running system or another device containing valuable data otherwise you risk
- * partial or complete loss of it.
+ * This file 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this file; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
-static void usage(const char *msg)
-{
- fprintf(stderr, "ERROR: %s\nusage: ./crypt_luks_usage <path>\n"
- "The <path> can refer to either a regular file or a block device.\n",
- msg ?: "");
-}
-int main(int argc, char **argv)
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <inttypes.h>
+#include <sys/types.h>
+#include <libcryptsetup.h>
+
+static int format_and_add_keyslots(const char *path)
{
- char *answer = NULL, *cipher, *cipher_mode, *dev;
- int step = 0, r;
- size_t size = 0;
- /* crypt device handle */
- struct crypt_active_device cad;
struct crypt_device *cd;
- struct crypt_params_luks1 params;
+ int r;
- if (geteuid())
- fprintf(stderr, "WARN: Process doesn't have super user privileges. "
- "Most of examples will fail because of that.\n");
+ /*
+ * The crypt_init() call is used to initialize crypt_device context,
+ * The path parameter specifies a device path.
+ *
+ * For path, you can use either link to a file or block device.
+ * The loopback device will be detached automatically.
+ */
- if (argc != 2) {
- usage("Wrong number of cmd line parameters.");
- exit(1);
+ r = crypt_init(&cd, path);
+ if (r < 0) {
+ printf("crypt_init() failed for %s.\n", path);
+ return r;
}
- dev = argv[1];
+ printf("Context is attached to block device %s.\n", crypt_get_device_name(cd));
/*
- * __STEP_01__
+ * So far, no data were written to the device.
+ */
+ printf("Device %s will be formatted as a LUKS device after 5 seconds.\n"
+ "Press CTRL+C now if you want to cancel this operation.\n", path);
+ sleep(5);
+
+ /*
+ * NULLs for uuid and volume_key means that these attributes will be
+ * generated during crypt_format().
+ */
+ r = crypt_format(cd, /* crypt context */
+ CRYPT_LUKS2, /* LUKS2 is a new LUKS format; use CRYPT_LUKS1 for LUKS1 */
+ "aes", /* used cipher */
+ "xts-plain64", /* used block mode and IV */
+ NULL, /* generate UUID */
+ NULL, /* generate volume key from RNG */
+ 512 / 8, /* 512bit key - here AES-256 in XTS mode, size is in bytes */
+ NULL); /* default parameters */
+
+ if (r < 0) {
+ printf("crypt_format() failed on device %s\n", crypt_get_device_name(cd));
+ crypt_free(cd);
+ return r;
+ }
+
+ /*
+ * The device now contains a LUKS header, but there is no active keyslot.
*
- * crypt_init() call precedes most of operations of cryptsetup API. The call is used
- * to initialize crypt device context stored in structure referenced by _cd_ in
- * the example. Second parameter is used to pass underlaying device path.
+ * crypt_keyslot_add_* call stores the volume_key in the encrypted form into the keyslot.
*
- * Note:
- * If path refers to a regular file it'll be attached to a first free loop device.
- * crypt_init() operation fails in case there's no more loop device available.
- * Also, loop device will have the AUTOCLEAR flag set, so the file will be
- * detached after crypt_free() call on the concerned context.
+ * After format, the volume key is stored internally.
*/
- EX_STEP(++step, "crypt_init()");
- if ((r = crypt_init(&cd, dev))) {
- EX_FAIL("crypt_init() failed for '%s'\n", dev ?: "(not set)");
+ r = crypt_keyslot_add_by_volume_key(cd, /* crypt context */
+ CRYPT_ANY_SLOT, /* just use first free slot */
+ NULL, /* use internal volume key */
+ 0, /* unused (size of volume key) */
+ "foo", /* passphrase - NULL means query*/
+ 3); /* size of passphrase */
+
+ if (r < 0) {
+ printf("Adding keyslot failed.\n");
+ crypt_free(cd);
return r;
}
- EX_SUCCESS("crypt_init() on '%s' has been successful", dev);
- if (strcmp(dev, crypt_get_device_name(cd)))
- printf("\tFile '%s' has been attached to %s\n", dev, crypt_get_device_name(cd));
- EX_DELIM;
+ printf("The first keyslot is initialized.\n");
+
/*
- * So far no data were written on your device. This will change with call of
- * crypt_format() only if you specify CRYPT_LUKS1 as device type.
+ * Add another keyslot, now authenticating with the first keyslot.
+ * It decrypts the volume key from the first keyslot and creates a new one with the specified passphrase.
*/
- printf("8 initial sectors of the device will be overwritten\n"
- "Are you sure you want to call crypt_format() over '%s'?\n"
- "If you're absolutely sure the device doesn't contain any valuable data,\n"
- "approve the operation by typing 'yes' in upper case: ", crypt_get_device_name(cd));
-
- if ((r = getline(&answer, &size, stdin)) == -1) {
- perror("getline");
- goto out;
+ r = crypt_keyslot_add_by_passphrase(cd, /* crypt context */
+ CRYPT_ANY_SLOT, /* just use first free slot */
+ "foo", 3, /* passphrase for the old keyslot */
+ "bar", 3); /* passphrase for the new kesylot */
+ if (r < 0) {
+ printf("Adding keyslot failed.\n");
+ crypt_free(cd);
+ return r;
}
- if (strcmp(answer, "YES\n"))
- goto out;
+ printf("The second keyslot is initialized.\n");
- /* Example of crypt_format() follows: */
+ crypt_free(cd);
+ return 0;
+}
- /*
- * cipher and cipher_mode:
- *
- * you'll get more on _cipher_ and _cipher_mode_ in man page
- * for cryptsetup userspace utility or at cryptsetup project
- * documentation.
- */
- cipher = "aes";
- cipher_mode = "cbc-essiv:sha256";
- params.hash = "sha1";
+static int activate_and_check_status(const char *path, const char *device_name)
+{
+ struct crypt_device *cd;
+ struct crypt_active_device cad;
+ int r;
/*
- * This parameter is relevant only in case of the luks header
- * and the payload are both stored on same device.
- *
- * In this particular case, payload offset (which is
- * computed internaly, according to volume key size)
- * is aligned to 2048 sectors
- *
- * if you set data_alignment = 0, cryptsetup will autodetect
- * data_alignment from underlaying device topology.
+ * LUKS device activation example.
*/
- params.data_alignment = 2048;
+ r = crypt_init(&cd, path);
+ if (r < 0) {
+ printf("crypt_init() failed for %s.\n", path);
+ return r;
+ }
/*
- * this parameter defines that no external device
- * for luks header will be used
+ * crypt_load() is used to load existing LUKS header from a block device
*/
- params.data_device = NULL;
+ r = crypt_load(cd, /* crypt context */
+ CRYPT_LUKS, /* requested type - here LUKS of any type */
+ NULL); /* additional parameters (not used) */
- /*
- * __STEP_02__
- *
- * NULLs for uuid and volume_key means that these attributes will be
- * generated during crypt_format(). Volume key is generated with respect
- * to key size parameter passed to function.
- *
- * Note that in crypt_format() device is checked wheter it's large enough to
- * store the luks header only.
- */
- EX_STEP(++step, "crypt_format()");
- if((r = crypt_format(cd, CRYPT_LUKS1, cipher, cipher_mode, NULL, NULL, KEY_SIZE, ¶ms))) {
- EX_FAIL("crypt_format() failed on device %s\n", crypt_get_device_name(cd));
- goto out;
+ if (r < 0) {
+ printf("crypt_load() failed on device %s.\n", crypt_get_device_name(cd));
+ crypt_free(cd);
+ return r;
}
- EX_SUCCESS("crypt_format() on device %s formated successfully. "
- "The device now contains LUKS1 header, but there is no active keyslot with encrypted "
- "volume key.", crypt_get_device_name(cd));
- EX_DELIM;
/*
- * __STEP_03__
- *
- * This call is intended to store volume_key in encrypted form into structure called keyslot.
- * Without keyslot you can't manipulate with LUKS device after the context will be freed.
- *
- * To create a new keyslot you need to supply the existing one (to get the volume key from) or
- * you need to supply the volume key. Now we have volume key stored internally and we have no active
- * keyslot so this the only option.
- *
+ * Device activation creates a device-mapper device with the specified name.
*/
- printf("Going to create a new keyslot...\n");
- EX_STEP(++step, "crypt_keyslot_add_by_volume_key()");
- if ((r = crypt_keyslot_add_by_volume_key(cd, CRYPT_ANY_SLOT, NULL, 0, NULL, 0)) < 0) {
- EX_FAIL("Adding keyslot failed.");
- goto out;
+ r = crypt_activate_by_passphrase(cd, /* crypt context */
+ device_name, /* device name to activate */
+ CRYPT_ANY_SLOT,/* the keyslot use (try all here) */
+ "foo", 3, /* passphrase */
+ CRYPT_ACTIVATE_READONLY); /* flags */
+ if (r < 0) {
+ printf("Device %s activation failed.\n", device_name);
+ crypt_free(cd);
+ return r;
}
- EX_SUCCESS("Keyslot nr. %d created successfully on device %s.", r, crypt_get_device_name(cd));
- EX_DELIM;
+
+ printf("%s device %s/%s is active.\n", crypt_get_type(cd), crypt_get_dir(), device_name);
+ printf("\tcipher used: %s\n", crypt_get_cipher(cd));
+ printf("\tcipher mode: %s\n", crypt_get_cipher_mode(cd));
+ printf("\tdevice UUID: %s\n", crypt_get_uuid(cd));
/*
- * __STEP_04__
- *
- * This is the example of the second method mentioned in STEP 03. By supplying passphrase for
- * the active keyslot you can create a new one.
+ * Get info about the active device.
*/
- printf("Now let's try to add a keyslot using the existing active keyslot\n");
- EX_STEP(++step, "crypt_keyslot_add_by_passphrase()");
- if ((r = crypt_keyslot_add_by_passphrase(cd, CRYPT_ANY_SLOT, NULL, 0, NULL, 0)) < 0) {
- EX_FAIL("Adding keyslot failed\n");
- goto out;
+ r = crypt_get_active_device(cd, device_name, &cad);
+ if (r < 0) {
+ printf("Get info about active device %s failed.\n", device_name);
+ crypt_deactivate(cd, device_name);
+ crypt_free(cd);
+ return r;
}
- EX_SUCCESS("Keyslot nr. %d created successfully and written on device %s.", r, crypt_get_device_name(cd));
- EX_DELIM;
+
+ printf("Active device parameters for %s:\n"
+ "\tDevice offset (in sectors): %" PRIu64 "\n"
+ "\tIV offset (in sectors) : %" PRIu64 "\n"
+ "\tdevice size (in sectors) : %" PRIu64 "\n"
+ "\tread-only flag : %s\n",
+ device_name, cad.offset, cad.iv_offset, cad.size,
+ cad.flags & CRYPT_ACTIVATE_READONLY ? "1" : "0");
crypt_free(cd);
- cd = NULL;
+ return 0;
+}
+
+static int handle_active_device(const char *device_name)
+{
+ struct crypt_device *cd;
+ int r;
/*
- * __STEP_05__
- *
- * In previous steps the device was formatted (LUKS header was written to backing device)
- * and keyslots were activated (volume key was written in two separate structures encrypted
- * by two user supplied passwords).
- *
- * This example demonstrates typical use case for LUKS device activation.
- * It's sequence of sub-steps: device initialization (crypt_init), LUKS header load (crypt_load())
- * and finally the device activation itself
- */
- EX_PRESS_ENTER("Device context going to be freed. New one will initialized to demonstrate activation process.");
- EX_STEP(++step, "crypt_init()");
- if ((r = crypt_init(&cd, dev))) {
- EX_FAIL("crypt_init() failed for '%s'!", dev);
- goto out;
- }
- EX_SUCCESS("crypt_init() on '%s' has been successful.", dev);
- if (strcmp(dev, crypt_get_device_name(cd)))
- printf("\tFile '%s' has been attached to %s\n", dev, crypt_get_device_name(cd));
- EX_DELIM;
- /* __STEP_05__
- *
- * crypt_load() is used to load the LUKS header from backing block device
- * into crypt_device context
+ * crypt_init_by_name() initializes context by an active device-mapper name
*/
- EX_PRESS_ENTER("Going to load LUKS header.");
- EX_STEP(step, "crypt_load()");
- if ((r = crypt_load(cd, CRYPT_LUKS1, ¶ms))) {
- EX_FAIL("crypt_load() failed on device '%s'!", crypt_get_device_name(cd));
- goto out;
+ r = crypt_init_by_name(&cd, device_name);
+ if (r < 0) {
+ printf("crypt_init_by_name() failed for %s.\n", device_name);
+ return r;
}
- EX_SUCCESS("crypt_load() successful. The header has been read from %s.", crypt_get_device_name(cd));
- EX_DELIM;
- /*
- * __STEP_05__
- *
- * Device activation creates mapping in device-mapper with name EX_DEV_NAME.
- * The volume key is stored into kernel mem. space and the encryption of backing
- * device is now set in motion.
- */
- printf("Going to activate LUKS device\n");
- EX_STEP(step, "crypt_activate_by_passphrase()");
- if ((r = crypt_activate_by_passphrase(cd, EX_DEV_NAME, CRYPT_ANY_SLOT, NULL, 0, 0)) < 0) {
- EX_FAIL("Device activation failed!");
- goto out;
+ if (crypt_status(cd, device_name) == CRYPT_ACTIVE)
+ printf("Device %s is still active.\n", device_name);
+ else {
+ printf("Something failed perhaps, device %s is not active.\n", device_name);
+ crypt_free(cd);
+ return -1;
}
- EX_SUCCESS("Encrypted device is active on " DMDIR EX_DEV_NAME ".");
- printf("\tThe cipher used in device context: '%s'\n", crypt_get_cipher(cd) ?: "(not set) !");
- printf("\tThe cipher mode used in device context: '%s'\n", crypt_get_cipher_mode(cd) ?: "(not set) !");
- printf("\tThe device UUID '%s'\n", crypt_get_uuid(cd) ?: "(not set) !");
- EX_DELIM;
/*
- * __STEP_06__
- *
- * Get info about active device (query DM backend)
+ * crypt_deactivate() is used to deactivate a device
*/
- EX_PRESS_ENTER("Going to get active active device parameters.");
- EX_STEP(++step, "crypt_get_active_device()");
- if ((r = crypt_get_active_device(cd, EX_DEV_NAME, &cad))) {
- EX_FAIL("Get info about active device '%s' failed!", EX_DEV_NAME);
- goto out;
+ r = crypt_deactivate(cd, device_name);
+ if (r < 0) {
+ printf("crypt_deactivate() failed.\n");
+ crypt_free(cd);
+ return r;
}
- EX_SUCCESS("Active device parameters for " EX_DEV_NAME ":\n"
- "\tPayload offset (in sectors): %" PRIu64 "\n"
- "\tEncrypted payload area size in sectors: %" PRIu64 " and bytes: %" PRIu64 "\n"
- "\tThe device has a read-only flag %sset",
- cad.offset, cad.size, cad.size * SECTOR_SIZE,
- cad.flags & CRYPT_ACTIVATE_READONLY ? "" : "not ");
- EX_DELIM;
+
+ printf("Device %s is now deactivated.\n", device_name);
crypt_free(cd);
- cd = NULL;
+ return 0;
+}
- /*
- * __STEP_07__
- *
- * crypt_init_by_name() initializes device context and loads LUKS header from backing device
- */
- EX_PRESS_ENTER("The context used in previous examples is going to be freed to demonstrate "
- "how to initialize a device context from the active device.");
- EX_STEP(++step, "crypt_init_by_name()");
- if ((r = crypt_init_by_name(&cd, EX_DEV_NAME))) {
- EX_FAIL("crypt_init_by_name() failed for the device name: " EX_DEV_NAME);
- goto out;
+int main(int argc, char **argv)
+{
+ if (geteuid()) {
+ printf("Using of libcryptsetup requires super user privileges.\n");
+ return 1;
}
- EX_SUCCESS("A new context has been initialized, LUKS header has been restored"
- "\n\tDevice UUID is '%s'", crypt_get_uuid(cd));
- /*
- * __STEP_08__
- *
- * crypt_deactivate() is used to remove the volume_key from kernel mem. space and to remove the
- * device nod associated with decrypted backing device.
- *
- */
- EX_PRESS_ENTER("\n\tGoing to deactivate the crypt device. Note that the device "
- "won't be deactivated while it's opened with O_EXCL flag (e.g. mounted).");
- EX_STEP(++step, "crypt_deactivate()");
- //printf("\nPress <ENTER> to continue to device deactivation of the test device.\n"
- // "Note that mounted device won't be deactivated. First unmount the device!");
- //getc(stdin);
- while ((r = crypt_deactivate(cd, EX_DEV_NAME))) {
- EX_FAIL("crypt_deactivate() failed. Most propably the device is still busy!");
- EX_PRESS_ENTER("Going to retry device deactivation");
+ if (argc != 2) {
+ printf("usage: ./crypt_luks_usage <path>\n"
+ "<path> refers to either a regular file or a block device.\n"
+ " WARNING: the file or device will be wiped.\n");
+ return 2;
}
- EX_SUCCESS("crypt_deactivate() successful. Device " DMDIR EX_DEV_NAME " is now deactivated");
-
-out:
- if (crypt_status(cd, EX_DEV_NAME) == CRYPT_ACTIVE)
- crypt_deactivate(cd, EX_DEV_NAME);
- if (answer)
- free(answer);
- /* always free context which is no longer used */
- if (cd)
- crypt_free(cd);
- return r;
+ if (format_and_add_keyslots(argv[1]))
+ return 3;
+
+ if (activate_and_check_status(argv[1], "example_device"))
+ return 4;
+
+ if (handle_active_device("example_device"))
+ return 5;
+
+ return 0;
}
projects / platform / upstream / cryptsetup.git / blobdiff