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e7d90b7127
systemd/src/cryptsetup/cryptsetup.c
Jan Janssen e7d90b7127 cryptsetup: Move password query out of main 
Also use _cleanup_free_ where possible.
2013-07-16 01:24:24 +02:00

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/*-*- 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 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 <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 "path-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 unsigned opt_keyfile_size = 0;
static unsigned opt_keyfile_offset = 0;
static char *opt_hash = NULL;
static unsigned opt_tries = 0;
static bool opt_readonly = false;
static bool opt_verify = false;
static bool opt_discards = 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") || streq(option, "nofail"))
return 0;
if (startswith(option, "cipher=")) {
char *t;
t = strdup(option+7);
if (!t)
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, "keyfile-size=")) {
if (safe_atou(option+13, &opt_keyfile_size) < 0) {
log_error("keyfile-size= parse failure, ignoring.");
return 0;
}
} else if (startswith(option, "keyfile-offset=")) {
if (safe_atou(option+15, &opt_keyfile_offset) < 0) {
log_error("keyfile-offset= parse failure, ignoring.");
return 0;
}
} else if (startswith(option, "hash=")) {
char *t;
t = strdup(option+5);
if (!t)
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") || streq(option, "read-only"))
opt_readonly = true;
else if (streq(option, "verify"))
opt_verify = true;
else if (streq(option, "allow-discards"))
opt_discards = 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_sec(option+8, &opt_timeout) < 0) {
log_error("timeout= parse failure, ignoring.");
return 0;
}
} else if (!streq(option, "none"))
log_error("Encountered unknown /etc/crypttab option '%s', ignoring.", option);
return 0;
}
static int parse_options(const char *options) {
char *state, *w;
size_t l;
int r;
assert(options);
FOREACH_WORD_SEPARATOR(w, l, options, ",", state) {
_cleanup_free_ char *o;
o = strndup(w, l);
if (!o)
return -ENOMEM;
r = parse_one_option(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) {
static const char name_fields[] = {
"ID_PART_ENTRY_NAME\0"
"DM_NAME\0"
"ID_MODEL_FROM_DATABASE\0"
"ID_MODEL\0"
};
struct udev *udev = NULL;
struct udev_device *device = NULL;
struct stat st;
char *description = NULL;
const char *i;
assert(path);
if (stat(path, &st) < 0)
return NULL;
if (!S_ISBLK(st.st_mode))
return NULL;
udev = udev_new();
if (!udev)
return NULL;
device = udev_device_new_from_devnum(udev, 'b', st.st_rdev);
if (!device)
goto finish;
NULSTR_FOREACH(i, name_fields) {
const char *name;
name = udev_device_get_property_value(device, i);
if (!isempty(name)) {
description = strdup(name);
break;
}
}
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;
_cleanup_free_ char *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;
f = setmntent("/etc/fstab", "r");
if (!f)
goto finish;
while ((m = getmntent(f)))
if (path_equal(m->mnt_fsname, device)) {
mp = strdup(m->mnt_dir);
break;
}
finish:
if (f)
endmntent(f);
return mp;
}
static int get_password(const char *name, usec_t until, bool accept_cached, char ***passwords) {
int r;
char **p;
_cleanup_free_ char *text = NULL;
assert(name);
assert(passwords);
if (asprintf(&text, "Please enter passphrase for disk %s!", name) < 0)
return log_oom();
r = ask_password_auto(text, "drive-harddisk", until, accept_cached, passwords);
if (r < 0) {
log_error("Failed to query password: %s", strerror(-r));
return r;
}
if (opt_verify) {
_cleanup_strv_free_ char **passwords2 = NULL;
assert(strv_length(*passwords) == 1);
if (asprintf(&text, "Please enter passphrase for disk %s! (verification)", name) < 0)
return log_oom();
r = ask_password_auto(text, "drive-harddisk", until, false, &passwords2);
if (r < 0) {
log_error("Failed to query verification password: %s", strerror(-r));
return r;
}
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 >= opt_key_size)
continue;
/* Pad password if necessary */
if (!(c = new(char, opt_key_size)))
return log_oom();
strncpy(c, *p, opt_key_size);
free(*p);
*p = c;
}
return 0;
}
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;
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();
umask(0022);
if (streq(argv[1], "attach")) {
uint32_t flags = 0;
int k;
unsigned try;
usec_t until;
crypt_status_info status;
const char *key_file = NULL, *cipher = NULL, *cipher_mode = NULL,
*hash = NULL, *name = NULL;
_cleanup_free_ char *description = NULL, *name_buffer = NULL,
*mount_point = NULL, *truncated_cipher = 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);
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];
k = crypt_init(&cd, argv[3]);
if (k) {
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_discards)
flags |= CRYPT_ACTIVATE_ALLOW_DISCARDS;
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);
if (opt_hash) {
/* plain isn't a real hash type. it just means "use no hash" */
if (!streq(opt_hash, "plain"))
hash = opt_hash;
} else
hash = "ripemd160";
if (opt_cipher) {
size_t l;
l = strcspn(opt_cipher, "-");
truncated_cipher = strndup(opt_cipher, l);
if (!truncated_cipher) {
log_oom();
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;
_cleanup_strv_free_ char **passwords = NULL;
if (!key_file) {
k = get_password(name, until, try == 0 && !opt_verify, &passwords);
if (k == -EAGAIN)
continue;
else if (k < 0)
goto finish;
}
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 = { .hash = hash };
/* for CRYPT_PLAIN limit reads
* from keyfile to key length, and
* ignore keyfile-size */
opt_keyfile_size = opt_key_size / 8;
/* 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_keyfile_size,
&params);
/* hash == NULL implies the user passed "plain" */
pass_volume_key = (hash == NULL);
}
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) {
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 && (st.st_mode & 0005))
log_warning("Key file %s is world-readable. That's certainly not a good idea.", key_file);
k = crypt_activate_by_keyfile_offset(
cd, argv[2], CRYPT_ANY_SLOT, key_file, opt_keyfile_size,
opt_keyfile_offset, flags);
if (k < 0) {
log_error("Failed to activate with key file '%s': %s", key_file, strerror(-k));
key_file = NULL;
continue;
}
} 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;
k = crypt_init_by_name(&cd, argv[2]);
if (k) {
log_error("crypt_init() failed: %s", strerror(-k));
goto finish;
}
crypt_set_log_callback(cd, log_glue, NULL);
k = crypt_deactivate(cd, argv[2]);
if (k < 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);
return r;
}
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