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Systemd/src/cryptsetup/cryptsetup.c

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/* SPDX-License-Identifier: LGPL-2.1+ */
/***
This file is part of systemd.
Copyright 2010 Lennart Poettering
systemd 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.
systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <errno.h>
#include <mntent.h>
#include <string.h>
#include <sys/mman.h>
#include "sd-device.h"
#include "alloc-util.h"
#include "ask-password-api.h"
#include "crypt-util.h"
#include "device-util.h"
#include "escape.h"
#include "fileio.h"
#include "log.h"
#include "mount-util.h"
#include "parse-util.h"
#include "path-util.h"
#include "string-util.h"
#include "strv.h"
#include "util.h"
/* internal helper */
#define ANY_LUKS "LUKS"
static const char *arg_type = NULL; /* ANY_LUKS, CRYPT_LUKS1, CRYPT_LUKS2, CRYPT_TCRYPT or CRYPT_PLAIN */
static char *arg_cipher = NULL;
static unsigned arg_key_size = 0;
static int arg_key_slot = CRYPT_ANY_SLOT;
static unsigned arg_keyfile_size = 0;
static uint64_t arg_keyfile_offset = 0;
static char *arg_hash = NULL;
static char *arg_header = NULL;
static unsigned arg_tries = 3;
static bool arg_readonly = false;
static bool arg_verify = false;
static bool arg_discards = false;
static bool arg_tcrypt_hidden = false;
static bool arg_tcrypt_system = false;
#ifdef CRYPT_TCRYPT_VERA_MODES
static bool arg_tcrypt_veracrypt = false;
#endif
static char **arg_tcrypt_keyfiles = NULL;
static uint64_t arg_offset = 0;
static uint64_t arg_skip = 0;
static usec_t arg_timeout = USEC_INFINITY;
/* Options Debian's crypttab knows we don't:
precheck=
check=
checkargs=
noearly=
loud=
keyscript=
*/
static int parse_one_option(const char *option) {
const char *val;
int r;
assert(option);
/* Handled outside of this tool */
if (STR_IN_SET(option, "noauto", "auto", "nofail", "fail", "_netdev"))
return 0;
if ((val = startswith(option, "cipher="))) {
r = free_and_strdup(&arg_cipher, val);
if (r < 0)
return log_oom();
} else if ((val = startswith(option, "size="))) {
r = safe_atou(val, &arg_key_size);
if (r < 0) {
log_error_errno(r, "Failed to parse %s, ignoring: %m", option);
return 0;
}
if (arg_key_size % 8) {
log_error("size= not a multiple of 8, ignoring.");
return 0;
}
arg_key_size /= 8;
} else if ((val = startswith(option, "key-slot="))) {
arg_type = ANY_LUKS;
r = safe_atoi(val, &arg_key_slot);
if (r < 0) {
log_error_errno(r, "Failed to parse %s, ignoring: %m", option);
return 0;
}
} else if ((val = startswith(option, "tcrypt-keyfile="))) {
arg_type = CRYPT_TCRYPT;
if (path_is_absolute(val)) {
if (strv_extend(&arg_tcrypt_keyfiles, val) < 0)
return log_oom();
} else
log_error("Key file path \"%s\" is not absolute. Ignoring.", val);
} else if ((val = startswith(option, "keyfile-size="))) {
r = safe_atou(val, &arg_keyfile_size);
if (r < 0) {
log_error_errno(r, "Failed to parse %s, ignoring: %m", option);
return 0;
}
} else if ((val = startswith(option, "keyfile-offset="))) {
uint64_t off;
r = safe_atou64(val, &off);
if (r < 0) {
log_error_errno(r, "Failed to parse %s, ignoring: %m", option);
return 0;
}
if ((size_t) off != off) {
/* https://gitlab.com/cryptsetup/cryptsetup/issues/359 */
log_error("keyfile-offset= value would truncated to %zu, ignoring.", (size_t) off);
return 0;
}
arg_keyfile_offset = off;
} else if ((val = startswith(option, "hash="))) {
r = free_and_strdup(&arg_hash, val);
if (r < 0)
return log_oom();
} else if ((val = startswith(option, "header="))) {
arg_type = ANY_LUKS;
if (!path_is_absolute(val)) {
log_error("Header path \"%s\" is not absolute, refusing.", val);
return -EINVAL;
}
if (arg_header) {
log_error("Duplicate header= option, refusing.");
return -EINVAL;
}
arg_header = strdup(val);
if (!arg_header)
return log_oom();
} else if ((val = startswith(option, "tries="))) {
r = safe_atou(val, &arg_tries);
if (r < 0) {
log_error_errno(r, "Failed to parse %s, ignoring: %m", option);
return 0;
}
} else if (STR_IN_SET(option, "readonly", "read-only"))
arg_readonly = true;
else if (streq(option, "verify"))
arg_verify = true;
else if (STR_IN_SET(option, "allow-discards", "discard"))
arg_discards = true;
else if (streq(option, "luks"))
arg_type = ANY_LUKS;
else if (streq(option, "tcrypt"))
arg_type = CRYPT_TCRYPT;
else if (streq(option, "tcrypt-hidden")) {
arg_type = CRYPT_TCRYPT;
arg_tcrypt_hidden = true;
} else if (streq(option, "tcrypt-system")) {
arg_type = CRYPT_TCRYPT;
arg_tcrypt_system = true;
} else if (streq(option, "tcrypt-veracrypt")) {
#ifdef CRYPT_TCRYPT_VERA_MODES
arg_type = CRYPT_TCRYPT;
arg_tcrypt_veracrypt = true;
#else
log_error("This version of cryptsetup does not support tcrypt-veracrypt; refusing.");
return -EINVAL;
#endif
} else if (STR_IN_SET(option, "plain", "swap", "tmp"))
arg_type = CRYPT_PLAIN;
else if ((val = startswith(option, "timeout="))) {
r = parse_sec_fix_0(val, &arg_timeout);
if (r < 0) {
log_error_errno(r, "Failed to parse %s, ignoring: %m", option);
return 0;
}
} else if ((val = startswith(option, "offset="))) {
r = safe_atou64(val, &arg_offset);
if (r < 0)
return log_error_errno(r, "Failed to parse %s: %m", option);
} else if ((val = startswith(option, "skip="))) {
r = safe_atou64(val, &arg_skip);
if (r < 0)
return log_error_errno(r, "Failed to parse %s: %m", option);
} else if (!streq(option, "none"))
log_warning("Encountered unknown /etc/crypttab option '%s', ignoring.", option);
return 0;
}
static int parse_options(const char *options) {
const char *word, *state;
size_t l;
int r;
assert(options);
FOREACH_WORD_SEPARATOR(word, l, options, ",", state) {
_cleanup_free_ char *o;
o = strndup(word, l);
if (!o)
return -ENOMEM;
r = parse_one_option(o);
if (r < 0)
return r;
}
/* sanity-check options */
if (arg_type != NULL && !streq(arg_type, CRYPT_PLAIN)) {
if (arg_offset)
log_warning("offset= ignored with type %s", arg_type);
if (arg_skip)
log_warning("skip= ignored with type %s", arg_type);
}
return 0;
}
static char* disk_description(const char *path) {
static const char name_fields[] =
"ID_PART_ENTRY_NAME\0"
"DM_NAME\0"
"ID_MODEL_FROM_DATABASE\0"
"ID_MODEL\0";
_cleanup_(sd_device_unrefp) sd_device *device = NULL;
struct stat st;
const char *i;
int r;
assert(path);
if (stat(path, &st) < 0)
return NULL;
if (!S_ISBLK(st.st_mode))
return NULL;
r = sd_device_new_from_devnum(&device, 'b', st.st_rdev);
if (r < 0)
return NULL;
NULSTR_FOREACH(i, name_fields) {
const char *name;
r = sd_device_get_property_value(device, i, &name);
if (r >= 0 && !isempty(name))
return strdup(name);
}
return NULL;
}
static char *disk_mount_point(const char *label) {
_cleanup_free_ char *device = NULL;
_cleanup_endmntent_ FILE *f = NULL;
struct mntent *m;
/* Yeah, we don't support native systemd unit files here for now */
if (asprintf(&device, "/dev/mapper/%s", label) < 0)
return NULL;
f = setmntent("/etc/fstab", "re");
if (!f)
return NULL;
while ((m = getmntent(f)))
if (path_equal(m->mnt_fsname, device))
return strdup(m->mnt_dir);
return NULL;
}
static int get_password(const char *vol, const char *src, usec_t until, bool accept_cached, char ***ret) {
_cleanup_free_ char *description = NULL, *name_buffer = NULL, *mount_point = NULL, *text = NULL, *disk_path = NULL;
_cleanup_strv_free_erase_ char **passwords = NULL;
const char *name = NULL;
char **p, *id;
int r = 0;
assert(vol);
assert(src);
assert(ret);
description = disk_description(src);
mount_point = disk_mount_point(vol);
disk_path = cescape(src);
if (!disk_path)
return log_oom();
if (description && streq(vol, description))
/* If the description string is simply the
* volume name, then let's not show this
* twice */
description = mfree(description);
if (mount_point && description)
r = asprintf(&name_buffer, "%s (%s) on %s", description, vol, mount_point);
else if (mount_point)
r = asprintf(&name_buffer, "%s on %s", vol, mount_point);
else if (description)
r = asprintf(&name_buffer, "%s (%s)", description, vol);
if (r < 0)
return log_oom();
name = name_buffer ? name_buffer : vol;
if (asprintf(&text, "Please enter passphrase for disk %s!", name) < 0)
return log_oom();
id = strjoina("cryptsetup:", disk_path);
r = ask_password_auto(text, "drive-harddisk", id, "cryptsetup", until,
ASK_PASSWORD_PUSH_CACHE | (accept_cached*ASK_PASSWORD_ACCEPT_CACHED),
&passwords);
if (r < 0)
return log_error_errno(r, "Failed to query password: %m");
if (arg_verify) {
_cleanup_strv_free_erase_ char **passwords2 = NULL;
assert(strv_length(passwords) == 1);
if (asprintf(&text, "Please enter passphrase for disk %s! (verification)", name) < 0)
return log_oom();
id = strjoina("cryptsetup-verification:", disk_path);
r = ask_password_auto(text, "drive-harddisk", id, "cryptsetup", until, ASK_PASSWORD_PUSH_CACHE, &passwords2);
if (r < 0)
return log_error_errno(r, "Failed to query verification password: %m");
assert(strv_length(passwords2) == 1);
if (!streq(passwords[0], passwords2[0])) {
log_warning("Passwords did not match, retrying.");
return -EAGAIN;
}
}
strv_uniq(passwords);
STRV_FOREACH(p, passwords) {
char *c;
if (strlen(*p)+1 >= arg_key_size)
continue;
/* Pad password if necessary */
c = new(char, arg_key_size);
if (!c)
return log_oom();
strncpy(c, *p, arg_key_size);
free(*p);
*p = c;
}
*ret = TAKE_PTR(passwords);
return 0;
}
static int attach_tcrypt(
struct crypt_device *cd,
const char *name,
const char *key_file,
char **passwords,
uint32_t flags) {
int r = 0;
_cleanup_free_ char *passphrase = NULL;
struct crypt_params_tcrypt params = {
.flags = CRYPT_TCRYPT_LEGACY_MODES,
.keyfiles = (const char **)arg_tcrypt_keyfiles,
.keyfiles_count = strv_length(arg_tcrypt_keyfiles)
};
assert(cd);
assert(name);
assert(key_file || (passwords && passwords[0]));
if (arg_tcrypt_hidden)
params.flags |= CRYPT_TCRYPT_HIDDEN_HEADER;
if (arg_tcrypt_system)
params.flags |= CRYPT_TCRYPT_SYSTEM_HEADER;
#ifdef CRYPT_TCRYPT_VERA_MODES
if (arg_tcrypt_veracrypt)
params.flags |= CRYPT_TCRYPT_VERA_MODES;
#endif
if (key_file) {
r = read_one_line_file(key_file, &passphrase);
if (r < 0) {
log_error_errno(r, "Failed to read password file '%s': %m", key_file);
return -EAGAIN;
}
params.passphrase = passphrase;
} else
params.passphrase = passwords[0];
params.passphrase_size = strlen(params.passphrase);
r = crypt_load(cd, CRYPT_TCRYPT, &params);
if (r < 0) {
if (key_file && r == -EPERM) {
log_error("Failed to activate using password file '%s'.", key_file);
return -EAGAIN;
}
return r;
}
return crypt_activate_by_volume_key(cd, name, NULL, 0, flags);
}
static int attach_luks_or_plain(struct crypt_device *cd,
const char *name,
const char *key_file,
const char *data_device,
char **passwords,
uint32_t flags) {
int r = 0;
bool pass_volume_key = false;
assert(cd);
assert(name);
assert(key_file || passwords);
if (!arg_type || STR_IN_SET(arg_type, ANY_LUKS, CRYPT_LUKS1)) {
r = crypt_load(cd, CRYPT_LUKS, NULL);
if (r < 0) {
log_error("crypt_load() failed on device %s.\n", crypt_get_device_name(cd));
return r;
}
if (data_device)
r = crypt_set_data_device(cd, data_device);
}
if ((!arg_type && r < 0) || streq_ptr(arg_type, CRYPT_PLAIN)) {
struct crypt_params_plain params = {
.offset = arg_offset,
.skip = arg_skip,
};
const char *cipher, *cipher_mode;
_cleanup_free_ char *truncated_cipher = NULL;
if (arg_hash) {
/* plain isn't a real hash type. it just means "use no hash" */
if (!streq(arg_hash, "plain"))
params.hash = arg_hash;
} else if (!key_file)
/* for CRYPT_PLAIN, the behaviour of cryptsetup
* package is to not hash when a key file is provided */
params.hash = "ripemd160";
if (arg_cipher) {
size_t l;
l = strcspn(arg_cipher, "-");
truncated_cipher = strndup(arg_cipher, l);
if (!truncated_cipher)
return log_oom();
cipher = truncated_cipher;
cipher_mode = arg_cipher[l] ? arg_cipher+l+1 : "plain";
} else {
cipher = "aes";
cipher_mode = "cbc-essiv:sha256";
}
/* for CRYPT_PLAIN limit reads
* from keyfile to key length, and
* ignore keyfile-size */
arg_keyfile_size = arg_key_size;
/* In contrast to what the name
* crypt_setup() might suggest this
* doesn't actually format anything,
* it just configures encryption
* parameters when used for plain
* mode. */
r = crypt_format(cd, CRYPT_PLAIN, cipher, cipher_mode, NULL, NULL, arg_keyfile_size, &params);
/* hash == NULL implies the user passed "plain" */
pass_volume_key = (params.hash == NULL);
}
if (r < 0)
return log_error_errno(r, "Loading of cryptographic parameters failed: %m");
log_info("Set cipher %s, mode %s, key size %i bits for device %s.",
crypt_get_cipher(cd),
crypt_get_cipher_mode(cd),
crypt_get_volume_key_size(cd)*8,
crypt_get_device_name(cd));
if (key_file) {
r = crypt_activate_by_keyfile_offset(cd, name, arg_key_slot, key_file, arg_keyfile_size, arg_keyfile_offset, flags);
if (r < 0) {
log_error_errno(r, "Failed to activate with key file '%s': %m", key_file);
return -EAGAIN;
}
} else {
char **p;
STRV_FOREACH(p, passwords) {
if (pass_volume_key)
r = crypt_activate_by_volume_key(cd, name, *p, arg_key_size, flags);
else
r = crypt_activate_by_passphrase(cd, name, arg_key_slot, *p, strlen(*p), flags);
if (r >= 0)
break;
}
}
return r;
}
static int help(void) {
printf("%s attach VOLUME SOURCEDEVICE [PASSWORD] [OPTIONS]\n"
"%s detach VOLUME\n\n"
"Attaches or detaches an encrypted block device.\n",
program_invocation_short_name,
program_invocation_short_name);
return 0;
}
int main(int argc, char *argv[]) {
_cleanup_(crypt_freep) struct crypt_device *cd = NULL;
int r = -EINVAL;
if (argc <= 1) {
r = help();
goto finish;
}
if (argc < 3) {
log_error("This program requires at least two arguments.");
goto finish;
}
log_set_target(LOG_TARGET_AUTO);
log_parse_environment();
log_open();
umask(0022);
if (streq(argv[1], "attach")) {
uint32_t flags = 0;
unsigned tries;
usec_t until;
crypt_status_info status;
const char *key_file = NULL;
/* Arguments: systemd-cryptsetup attach VOLUME SOURCE-DEVICE [PASSWORD] [OPTIONS] */
if (argc < 4) {
log_error("attach requires at least two arguments.");
goto finish;
}
if (argc >= 5 &&
argv[4][0] &&
!streq(argv[4], "-") &&
!streq(argv[4], "none")) {
if (!path_is_absolute(argv[4]))
log_error("Password file path '%s' is not absolute. Ignoring.", argv[4]);
else
key_file = argv[4];
}
if (argc >= 6 && argv[5][0] && !streq(argv[5], "-")) {
if (parse_options(argv[5]) < 0)
goto finish;
}
/* A delicious drop of snake oil */
mlockall(MCL_FUTURE);
if (arg_header) {
log_debug("LUKS header: %s", arg_header);
r = crypt_init(&cd, arg_header);
} else
r = crypt_init(&cd, argv[3]);
if (r < 0) {
log_error_errno(r, "crypt_init() failed: %m");
goto finish;
}
crypt_set_log_callback(cd, cryptsetup_log_glue, NULL);
status = crypt_status(cd, argv[2]);
if (IN_SET(status, CRYPT_ACTIVE, CRYPT_BUSY)) {
log_info("Volume %s already active.", argv[2]);
r = 0;
goto finish;
}
if (arg_readonly)
flags |= CRYPT_ACTIVATE_READONLY;
if (arg_discards)
flags |= CRYPT_ACTIVATE_ALLOW_DISCARDS;
if (arg_timeout == USEC_INFINITY)
until = 0;
else
until = now(CLOCK_MONOTONIC) + arg_timeout;
arg_key_size = (arg_key_size > 0 ? arg_key_size : (256 / 8));
if (key_file) {
struct stat st;
/* Ideally we'd do this on the open fd, but since this is just a
* warning it's OK to do this in two steps. */
if (stat(key_file, &st) >= 0 && S_ISREG(st.st_mode) && (st.st_mode & 0005))
log_warning("Key file %s is world-readable. This is not a good idea!", key_file);
}
for (tries = 0; arg_tries == 0 || tries < arg_tries; tries++) {
_cleanup_strv_free_erase_ char **passwords = NULL;
if (!key_file) {
r = get_password(argv[2], argv[3], until, tries == 0 && !arg_verify, &passwords);
if (r == -EAGAIN)
continue;
if (r < 0)
goto finish;
}
if (streq_ptr(arg_type, CRYPT_TCRYPT))
r = attach_tcrypt(cd, argv[2], key_file, passwords, flags);
else
r = attach_luks_or_plain(cd,
argv[2],
key_file,
arg_header ? argv[3] : NULL,
passwords,
flags);
if (r >= 0)
break;
if (r == -EAGAIN) {
key_file = NULL;
continue;
}
if (r != -EPERM) {
log_error_errno(r, "Failed to activate: %m");
goto finish;
}
log_warning("Invalid passphrase.");
}
if (arg_tries != 0 && tries >= arg_tries) {
log_error("Too many attempts; giving up.");
r = -EPERM;
goto finish;
}
} else if (streq(argv[1], "detach")) {
r = crypt_init_by_name(&cd, argv[2]);
if (r == -ENODEV) {
log_info("Volume %s already inactive.", argv[2]);
r = 0;
goto finish;
}
if (r < 0) {
log_error_errno(r, "crypt_init_by_name() failed: %m");
goto finish;
}
crypt_set_log_callback(cd, cryptsetup_log_glue, NULL);
r = crypt_deactivate(cd, argv[2]);
if (r < 0) {
log_error_errno(r, "Failed to deactivate: %m");
goto finish;
}
} else {
log_error("Unknown verb %s.", argv[1]);
goto finish;
}
r = 0;
finish:
free(arg_cipher);
free(arg_hash);
free(arg_header);
strv_free(arg_tcrypt_keyfiles);
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}
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