#include <string.h>

#include <errno.h>

#include <sys/mman.h>

#include <mntent.h>

#include <libcryptsetup.h>

#include "fileio.h"

#include "log.h"

#include "util.h"

#include "path-util.h"

#include "strv.h"

#include "ask-password-api.h"

#include "sd-device.h"

#include "device-util.h"

static const char *arg_type = NULL; /* CRYPT_LUKS1, 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 unsigned 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;

static char **arg_tcrypt_keyfiles = NULL;

static uint64_t arg_offset = 0;

static uint64_t arg_skip = 0;

static usec_t arg_timeout = 0;

static int parse_one_option(const char *option) {

assert(option);

/* Handled outside of this tool */

if (STR_IN_SET(option, "noauto", "auto", "nofail", "fail"))

return 0;

if (startswith(option, "cipher=")) {

char *t;

t = strdup(option+7);

if (!t)

return log_oom();

free(arg_cipher);

arg_cipher = t;

} else if (startswith(option, "size=")) {

if (safe_atou(option+5, &arg_key_size) < 0) {

log_error("size= parse failure, ignoring.");

return 0;

}

if (arg_key_size % 8) {

log_error("size= not a multiple of 8, ignoring.");

return 0;

}

arg_key_size /= 8;

} else if (startswith(option, "key-slot=")) {

arg_type = CRYPT_LUKS1;

if (safe_atoi(option+9, &arg_key_slot) < 0) {

log_error("key-slot= parse failure, ignoring.");

return 0;

}

} else if (startswith(option, "tcrypt-keyfile=")) {

arg_type = CRYPT_TCRYPT;

if (path_is_absolute(option+15)) {

if (strv_extend(&arg_tcrypt_keyfiles, option + 15) < 0)

return log_oom();

} else

log_error("Key file path '%s' is not absolute. Ignoring.", option+15);

} else if (startswith(option, "keyfile-size=")) {

if (safe_atou(option+13, &arg_keyfile_size) < 0) {

log_error("keyfile-size= parse failure, ignoring.");

return 0;

}

} else if (startswith(option, "keyfile-offset=")) {

if (safe_atou(option+15, &arg_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 log_oom();

free(arg_hash);

arg_hash = t;

} else if (startswith(option, "header=")) {

arg_type = CRYPT_LUKS1;

if (!path_is_absolute(option+7)) {

log_error("Header path '%s' is not absolute, refusing.", option+7);

return -EINVAL;

}

if (arg_header) {

log_error("Duplicate header= options, refusing.");

return -EINVAL;

}

arg_header = strdup(option+7);

if (!arg_header)

return log_oom();

} else if (startswith(option, "tries=")) {

if (safe_atou(option+6, &arg_tries) < 0) {

log_error("tries= parse failure, ignoring.");

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 = CRYPT_LUKS1;

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 (STR_IN_SET(option, "plain", "swap", "tmp"))

arg_type = CRYPT_PLAIN;

else if (startswith(option, "timeout=")) {

if (parse_sec(option+8, &arg_timeout) < 0) {

log_error("timeout= parse failure, ignoring.");

return 0;

}

} else if (startswith(option, "offset=")) {

if (safe_atou64(option+7, &arg_offset) < 0) {

log_error("offset= parse failure, refusing.");

return -EINVAL;

}

} else if (startswith(option, "skip=")) {

if (safe_atou64(option+5, &arg_skip) < 0) {

log_error("skip= parse failure, refusing.");

return -EINVAL;

}

} else if (!streq(option, "none"))

log_error("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 void log_glue(int level, const char *msg, void *usrptr) {

log_debug("%s", msg);

}

static int disk_major_minor(const char *path, char **ret) {

struct stat st;

assert(path);

if (stat(path, &st) < 0)

return -errno;

if (!S_ISBLK(st.st_mode))

return -EINVAL;

if (asprintf(ret, "/dev/block/%d:%d", major(st.st_rdev), minor(st.st_rdev)) < 0)

return -errno;

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_device_unref_ 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", "r");

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, *maj_min = NULL, *text = NULL, *escaped_name = NULL;

_cleanup_strv_free_ char **passwords = NULL, **passwords2 = 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);

if (description && streq(vol, description))

/* If the description string is simply the

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();

if (src)

(void) disk_major_minor(src, &maj_min);

if (maj_min) {

escaped_name = maj_min;

maj_min = NULL;

} else

escaped_name = cescape(name);

if (!escaped_name)

return log_oom();

id = strjoina("cryptsetup:", escaped_name);

r = ask_password_auto(text, "drive-harddisk", id, "cryptsetup", until, ASK_PASSWORD_PUSH_CACHE|(accept_cached ? ASK_PASSWORD_ACCEPT_CACHED : 0), &passwords);

if (r < 0)

return log_error_errno(r, "Failed to query password: %m");

if (arg_verify) {

assert(strv_length(passwords) == 1);

if (asprintf(&text, "Please enter passphrase for disk %s! (verification)", name) < 0) {

r = log_oom();

goto finish;

}

id = strjoina("cryptsetup-verification:", escaped_name);

r = ask_password_auto(text, "drive-harddisk", id, "cryptsetup", until, ASK_PASSWORD_PUSH_CACHE, &passwords2);

if (r < 0) {

log_error_errno(r, "Failed to query verification password: %m");

goto finish;

}

assert(strv_length(passwords2) == 1);

if (!streq(passwords[0], passwords2[0])) {

log_warning("Passwords did not match, retrying.");

r = -EAGAIN;

goto finish;

}

}

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) {

r = -ENOMEM;

goto finish;

}

strncpy(c, *p, arg_key_size);

free(*p);

*p = c;

}

*ret = passwords;

passwords = NULL;

r = 0;

finish:

strv_erase(passwords);

strv_erase(passwords2);

return r;

}

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;

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 || streq(arg_type, CRYPT_LUKS1)) {

r = crypt_load(cd, CRYPT_LUKS1, 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

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

arg_keyfile_size = arg_key_size;

/* In contrast to what the name

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[]) {

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 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);

k = crypt_init(&cd, arg_header);

} else

k = crypt_init(&cd, argv[3]);

if (k) {

log_error_errno(k, "crypt_init() failed: %m");

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 (arg_readonly)

flags |= CRYPT_ACTIVATE_READONLY;

if (arg_discards)

flags |= CRYPT_ACTIVATE_ALLOW_DISCARDS;

if (arg_timeout > 0)

until = now(CLOCK_MONOTONIC) + arg_timeout;

else

until = 0;

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

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_ char **passwords = NULL;

if (!key_file) {

k = get_password(argv[2], argv[3], until, tries == 0 && !arg_verify, &passwords);

if (k == -EAGAIN)

continue;

else if (k < 0)

goto finish;

}

if (streq_ptr(arg_type, CRYPT_TCRYPT))

k = attach_tcrypt(cd, argv[2], key_file, passwords, flags);

else

k = attach_luks_or_plain(cd,

argv[2],

key_file,

arg_header ? argv[3] : NULL,

passwords,

flags);

strv_erase(passwords);

if (k >= 0)

break;

else if (k == -EAGAIN) {

key_file = NULL;

continue;

} else if (k != -EPERM) {

log_error_errno(k, "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 = EXIT_FAILURE;

goto finish;

}

} else if (streq(argv[1], "detach")) {

int k;

k = crypt_init_by_name(&cd, argv[2]);

if (k) {

log_error_errno(k, "crypt_init() failed: %m");

goto finish;

}

crypt_set_log_callback(cd, log_glue, NULL);

k = crypt_deactivate(cd, argv[2]);

if (k < 0) {

log_error_errno(k, "Failed to deactivate: %m");

goto finish;

}

} else {

log_error("Unknown verb %s.", argv[1]);

goto finish;

}

r = EXIT_SUCCESS;

finish:

if (cd)

crypt_free(cd);

free(arg_cipher);

free(arg_hash);

free(arg_header);

strv_free(arg_tcrypt_keyfiles);

return r;

}