Systemd/src/cryptsetup.c
Milan Broz 2d745456b2 cryptsetup: fix keyfile size option processing
/etc/crypttab uses "size" argument only for plain crypt mapping
(and input is limited to volume key size)

For LUKS it always read whole keyfile (no arguments except "luks"
should be in crypttab).

Because of bug in cryptsetup 1.2.0 (fixed in 1.3.0) library
did not enforced keyfile size argument, so this bug was
hidden for some time.

Patch also converts size in bits to bytes like excepted
by libcryptsetup api.

Fixes https://bugs.freedesktop.org/show_bug.cgi?id=36264
2011-04-26 21:50:15 +02:00

528 lines
18 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 <mntent.h>
#include <libcryptsetup.h>
#include <libudev.h>
#include "log.h"
#include "util.h"
#include "strv.h"
#include "ask-password-api.h"
#include "def.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 = DEFAULT_TIMEOUT_USEC;
/* 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")) ||
(model = udev_device_get_property_value(device, "DM_NAME")))
description = strdup(model);
finish:
if (device)
udev_device_unref(device);
if (udev)
udev_unref(udev);
return description;
}
static char *disk_mount_point(const char *label) {
char *mp = NULL, *device = NULL;
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)
goto finish;
if (!(f = setmntent("/etc/fstab", "r")))
goto finish;
while ((m = getmntent(f)))
if (path_equal(m->mnt_fsname, device)) {
mp = strdup(m->mnt_dir);
break;
}
finish:
if (f)
endmntent(f);
free(device);
return mp;
}
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[]) {
int r = EXIT_FAILURE;
struct crypt_device *cd = NULL;
char **passwords = NULL, *truncated_cipher = NULL;
const char *cipher = NULL, *cipher_mode = NULL, *hash = NULL, *name = NULL;
char *description = NULL, *name_buffer = NULL, *mount_point = NULL;
unsigned keyfile_size = 0;
if (argc <= 1) {
help();
return EXIT_SUCCESS;
}
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;
/* 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], "-"))
parse_options(argv[5]);
/* A delicious drop of snake oil */
mlockall(MCL_FUTURE);
description = disk_description(argv[3]);
mount_point = disk_mount_point(argv[2]);
if (description && streq(argv[2], description)) {
/* If the description string is simply the
* volume name, then let's not show this
* twice */
free(description);
description = NULL;
}
if (mount_point && description)
asprintf(&name_buffer, "%s (%s) on %s", description, argv[2], mount_point);
else if (mount_point)
asprintf(&name_buffer, "%s on %s", argv[2], mount_point);
else if (description)
asprintf(&name_buffer, "%s (%s)", description, argv[2]);
name = name_buffer ? name_buffer : 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;
if (opt_timeout > 0)
until = now(CLOCK_MONOTONIC) + opt_timeout;
else
until = 0;
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;
strv_free(passwords);
passwords = NULL;
if (!key_file) {
char *text;
char **p;
if (asprintf(&text, "Please enter passphrase for disk %s!", name) < 0) {
log_error("Out of memory");
goto finish;
}
k = ask_password_auto(text, "drive-harddisk", until, try == 0 && !opt_verify, &passwords);
free(text);
if (k < 0) {
log_error("Failed to query password: %s", strerror(-k));
goto finish;
}
if (opt_verify) {
char **passwords2 = NULL;
assert(strv_length(passwords) == 1);
if (asprintf(&text, "Please enter passphrase for disk %s! (verification)", name) < 0) {
log_error("Out of memory");
goto finish;
}
k = ask_password_auto(text, "drive-harddisk", until, false, &passwords2);
free(text);
if (k < 0) {
log_error("Failed to query verification password: %s", strerror(-k));
goto finish;
}
assert(strv_length(passwords2) == 1);
if (!streq(passwords[0], passwords2[0])) {
log_warning("Passwords did not match, retrying.");
strv_free(passwords2);
continue;
}
strv_free(passwords2);
}
strv_uniq(passwords);
STRV_FOREACH(p, passwords) {
char *c;
if (strlen(*p)+1 >= opt_key_size)
continue;
/* Pad password if necessary */
if (!(c = new(char, opt_key_size))) {
log_error("Out of memory.");
goto finish;
}
strncpy(c, *p, opt_key_size);
free(*p);
*p = c;
}
}
k = 0;
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");
/* for CRYPT_PLAIN limit reads
* from keyfile to key length */
keyfile_size = opt_key_size / 8;
}
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, keyfile_size, flags);
else {
char **p;
STRV_FOREACH(p, passwords) {
if (pass_volume_key)
k = crypt_activate_by_volume_key(cd, argv[2], *p, opt_key_size, flags);
else
k = crypt_activate_by_passphrase(cd, argv[2], CRYPT_ANY_SLOT, *p, strlen(*p), flags);
if (k >= 0)
break;
}
}
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;
goto finish;
}
} 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);
strv_free(passwords);
free(description);
free(mount_point);
free(name_buffer);
return r;
}