diff options
Diffstat (limited to 'src/systemd-cryptsetup/cryptsetup.c')
-rw-r--r-- | src/systemd-cryptsetup/cryptsetup.c | 753 |
1 files changed, 753 insertions, 0 deletions
diff --git a/src/systemd-cryptsetup/cryptsetup.c b/src/systemd-cryptsetup/cryptsetup.c new file mode 100644 index 0000000000..2ef966257a --- /dev/null +++ b/src/systemd-cryptsetup/cryptsetup.c @@ -0,0 +1,753 @@ +/*** + 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 <libcryptsetup.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 "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" + +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; + +/* Options Debian's crypttab knows we don't: + + precheck= + check= + checkargs= + noearly= + loud= + keyscript= +*/ + +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_(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", "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_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); + + 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(); + + 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), + &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:", escaped_name); + + 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 = passwords; + passwords = NULL; + + 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; + + 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, ¶ms); + 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 + * 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, ¶ms); + + /* 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 + * 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) { + 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); + 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; +} |