Systemd/src/cryptsetup.c

429 lines
14 KiB
C

/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
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 General Public License as published by
the Free Software Foundation; either version 2 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
General Public License for more details.
You should have received a copy of the GNU General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <string.h>
#include <errno.h>
#include <sys/mman.h>
#include <libcryptsetup.h>
#include <libudev.h>
#include "log.h"
#include "util.h"
#include "ask-password-api.h"
static const char *opt_type = NULL; /* LUKS1 or PLAIN */
static char *opt_cipher = NULL;
static unsigned opt_key_size = 0;
static char *opt_hash = NULL;
static unsigned opt_tries = 0;
static bool opt_readonly = false;
static bool opt_verify = false;
static usec_t opt_timeout = 0;
/* Options Debian's crypttab knows we don't:
offset=
skip=
precheck=
check=
checkargs=
noearly=
loud=
keyscript=
*/
static int parse_one_option(const char *option) {
assert(option);
/* Handled outside of this tool */
if (streq(option, "noauto"))
return 0;
if (startswith(option, "cipher=")) {
char *t;
if (!(t = strdup(option+7)))
return -ENOMEM;
free(opt_cipher);
opt_cipher = t;
} else if (startswith(option, "size=")) {
if (safe_atou(option+5, &opt_key_size) < 0) {
log_error("size= parse failure, ignoring.");
return 0;
}
} else if (startswith(option, "hash=")) {
char *t;
if (!(t = strdup(option+5)))
return -ENOMEM;
free(opt_hash);
opt_hash = t;
} else if (startswith(option, "tries=")) {
if (safe_atou(option+6, &opt_tries) < 0) {
log_error("tries= parse failure, ignoring.");
return 0;
}
} else if (streq(option, "readonly"))
opt_readonly = true;
else if (streq(option, "verify"))
opt_verify = true;
else if (streq(option, "luks"))
opt_type = CRYPT_LUKS1;
else if (streq(option, "plain") ||
streq(option, "swap") ||
streq(option, "tmp"))
opt_type = CRYPT_PLAIN;
else if (startswith(option, "timeout=")) {
if (parse_usec(option+8, &opt_timeout) < 0) {
log_error("timeout= parse failure, ignoring.");
return 0;
}
} else
log_error("Encountered unknown /etc/crypttab option '%s', ignoring.", option);
return 0;
}
static int parse_options(const char *options) {
char *state;
char *w;
size_t l;
assert(options);
FOREACH_WORD_SEPARATOR(w, l, options, ",", state) {
char *o;
int r;
if (!(o = strndup(w, l)))
return -ENOMEM;
r = parse_one_option(o);
free(o);
if (r < 0)
return r;
}
return 0;
}
static void log_glue(int level, const char *msg, void *usrptr) {
log_debug("%s", msg);
}
static char *disk_description(const char *path) {
struct udev *udev = NULL;
struct udev_device *device = NULL;
struct stat st;
char *description = NULL;
const char *model;
assert(path);
if (stat(path, &st) < 0)
return NULL;
if (!S_ISBLK(st.st_mode))
return NULL;
if (!(udev = udev_new()))
return NULL;
if (!(device = udev_device_new_from_devnum(udev, 'b', st.st_rdev)))
goto finish;
if ((model = udev_device_get_property_value(device, "ID_MODEL_FROM_DATABASE")) ||
(model = udev_device_get_property_value(device, "ID_MODEL")))
description = strdup(model);
finish:
if (device)
udev_device_unref(device);
if (udev)
udev_unref(udev);
return description;
}
int main(int argc, char *argv[]) {
int r = EXIT_FAILURE;
struct crypt_device *cd = NULL;
char *password = NULL, *truncated_cipher = NULL;
const char *cipher = NULL, *cipher_mode = NULL, *hash = NULL, *name = NULL;
char *description = NULL;
if (argc < 3) {
log_error("This program requires at least two arguments.");
return EXIT_FAILURE;
}
log_set_target(LOG_TARGET_AUTO);
log_parse_environment();
log_open();
if (streq(argv[1], "attach")) {
uint32_t flags = 0;
int k;
unsigned try;
const char *key_file = NULL;
usec_t until;
crypt_status_info status;
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], "-"))
parse_options(argv[5]);
/* A delicious drop of snake oil */
mlockall(MCL_FUTURE);
description = disk_description(argv[3]);
name = description ? description : argv[2];
if ((k = crypt_init(&cd, argv[3]))) {
log_error("crypt_init() failed: %s", strerror(-k));
goto finish;
}
crypt_set_log_callback(cd, log_glue, NULL);
status = crypt_status(cd, argv[2]);
if (status == CRYPT_ACTIVE || status == CRYPT_BUSY) {
log_info("Volume %s already active.", argv[2]);
r = EXIT_SUCCESS;
goto finish;
}
if (opt_readonly)
flags |= CRYPT_ACTIVATE_READONLY;
until = now(CLOCK_MONOTONIC) + (opt_timeout > 0 ? opt_timeout : 60 * USEC_PER_SEC);
opt_tries = opt_tries > 0 ? opt_tries : 3;
opt_key_size = (opt_key_size > 0 ? opt_key_size : 256);
hash = opt_hash ? opt_hash : "ripemd160";
if (opt_cipher) {
size_t l;
l = strcspn(opt_cipher, "-");
if (!(truncated_cipher = strndup(opt_cipher, l))) {
log_error("Out of memory");
goto finish;
}
cipher = truncated_cipher;
cipher_mode = opt_cipher[l] ? opt_cipher+l+1 : "plain";
} else {
cipher = "aes";
cipher_mode = "cbc-essiv:sha256";
}
for (try = 0; try < opt_tries; try++) {
bool pass_volume_key = false;
free(password);
password = NULL;
if (!key_file) {
char *text;
if (asprintf(&text, "Please enter passphrase for disk %s!", argv[2]) < 0) {
log_error("Out of memory");
goto finish;
}
k = ask_password_auto(text, "drive-harddisk", until, &password);
free(text);
if (k < 0) {
log_error("Failed to query password: %s", strerror(-k));
goto finish;
}
if (opt_verify) {
char *password2 = NULL;
if (asprintf(&text, "Please enter passphrase for disk %s! (verification)", argv[2]) < 0) {
log_error("Out of memory");
goto finish;
}
k = ask_password_auto(text, "drive-harddisk", until, &password2);
free(text);
if (k < 0) {
log_error("Failed to query verification password: %s", strerror(-k));
goto finish;
}
if (!streq(password, password2)) {
log_warning("Passwords did not match, retrying.");
free(password2);
continue;
}
free(password2);
}
if (strlen(password)+1 < opt_key_size) {
char *c;
/* Pad password if necessary */
if (!(c = new(char, opt_key_size))) {
log_error("Out of memory.");
goto finish;
}
strncpy(c, password, opt_key_size);
free(password);
password = c;
}
}
if (!opt_type || streq(opt_type, CRYPT_LUKS1))
k = crypt_load(cd, CRYPT_LUKS1, NULL);
if ((!opt_type && k < 0) || streq_ptr(opt_type, CRYPT_PLAIN)) {
struct crypt_params_plain params;
zero(params);
params.hash = hash;
/* 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. */
k = crypt_format(cd, CRYPT_PLAIN,
cipher,
cipher_mode,
NULL,
NULL,
opt_key_size / 8,
&params);
pass_volume_key = streq(hash, "plain");
}
if (k < 0) {
log_error("Loading of cryptographic parameters failed: %s", strerror(-k));
goto finish;
}
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,
argv[3]);
if (key_file)
k = crypt_activate_by_keyfile(cd, argv[2], CRYPT_ANY_SLOT, key_file, opt_key_size, flags);
else if (pass_volume_key)
k = crypt_activate_by_volume_key(cd, argv[2], password, opt_key_size, flags);
else
k = crypt_activate_by_passphrase(cd, argv[2], CRYPT_ANY_SLOT, password, strlen(password), flags);
if (k >= 0)
break;
if (k != -EPERM) {
log_error("Failed to activate: %s", strerror(-k));
goto finish;
}
log_warning("Invalid passphrase.");
}
if (try >= opt_tries) {
log_error("Too many attempts.");
r = EXIT_FAILURE;
}
} else if (streq(argv[1], "detach")) {
int k;
if ((k = crypt_init_by_name(&cd, argv[2]))) {
log_error("crypt_init() failed: %s", strerror(-k));
goto finish;
}
crypt_set_log_callback(cd, log_glue, NULL);
if ((k = crypt_deactivate(cd, argv[2])) < 0) {
log_error("Failed to deactivate: %s", strerror(-k));
goto finish;
}
} else {
log_error("Unknown verb %s.", argv[1]);
goto finish;
}
r = EXIT_SUCCESS;
finish:
if (cd)
crypt_free(cd);
free(opt_cipher);
free(opt_hash);
free(truncated_cipher);
free(password);
free(description);
return r;
}