diff options
Diffstat (limited to 'src/home/homework.c')
| -rw-r--r-- | src/home/homework.c | 1979 |
1 files changed, 1979 insertions, 0 deletions
diff --git a/src/home/homework.c b/src/home/homework.c new file mode 100644 index 0000000..c41866c --- /dev/null +++ b/src/home/homework.c @@ -0,0 +1,1979 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <stddef.h> +#include <sys/mount.h> + +#include "blockdev-util.h" +#include "chown-recursive.h" +#include "copy.h" +#include "fd-util.h" +#include "fileio.h" +#include "filesystems.h" +#include "fs-util.h" +#include "home-util.h" +#include "homework-cifs.h" +#include "homework-directory.h" +#include "homework-fido2.h" +#include "homework-fscrypt.h" +#include "homework-luks.h" +#include "homework-mount.h" +#include "homework-pkcs11.h" +#include "homework.h" +#include "libcrypt-util.h" +#include "main-func.h" +#include "memory-util.h" +#include "missing_magic.h" +#include "mount-util.h" +#include "path-util.h" +#include "recovery-key.h" +#include "rm-rf.h" +#include "stat-util.h" +#include "strv.h" +#include "sync-util.h" +#include "tmpfile-util.h" +#include "user-util.h" +#include "virt.h" + +/* Make sure a bad password always results in a 3s delay, no matter what */ +#define BAD_PASSWORD_DELAY_USEC (3 * USEC_PER_SEC) + +int user_record_authenticate( + UserRecord *h, + UserRecord *secret, + PasswordCache *cache, + bool strict_verify) { + + bool need_password = false, need_recovery_key = false, need_token = false, need_pin = false, + need_protected_authentication_path_permitted = false, need_user_presence_permitted = false, + need_user_verification_permitted = false, pin_locked = false, pin_incorrect = false, + pin_incorrect_few_tries_left = false, pin_incorrect_one_try_left = false, token_action_timeout = false; + int r; + + assert(h); + assert(secret); + + /* Tries to authenticate a user record with the supplied secrets. i.e. checks whether at least one + * supplied plaintext passwords matches a hashed password field of the user record. Or if a + * configured PKCS#11 or FIDO2 token is around and can unlock the record. + * + * Note that the 'cache' parameter is both an input and output parameter: it contains lists of + * configured, decrypted PKCS#11/FIDO2 passwords. We typically have to call this function multiple + * times over the course of an operation (think: on login we authenticate the host user record, the + * record embedded in the LUKS record and the one embedded in $HOME). Hence we keep a list of + * passwords we already decrypted, so that we don't have to do the (slow and potentially interactive) + * PKCS#11/FIDO2 dance for the relevant token again and again. */ + + /* First, let's see if the supplied plain-text passwords work? */ + r = user_record_test_password(h, secret); + if (r == -ENOKEY) + need_password = true; + else if (r == -ENXIO) + log_debug_errno(r, "User record has no hashed passwords, plaintext passwords not tested."); + else if (r < 0) + return log_error_errno(r, "Failed to validate password of record: %m"); + else { + log_info("Provided password unlocks user record."); + return 1; + } + + /* Similar, but test against the recovery keys */ + r = user_record_test_recovery_key(h, secret); + if (r == -ENOKEY) + need_recovery_key = true; + else if (r == -ENXIO) + log_debug_errno(r, "User record has no recovery keys, plaintext passwords not tested against it."); + else if (r < 0) + return log_error_errno(r, "Failed to validate the recovery key of the record: %m"); + else { + log_info("Provided password is a recovery key that unlocks the user record."); + return 1; + } + + if (need_password && need_recovery_key) + log_info("None of the supplied plaintext passwords unlock the user record's hashed passwords or recovery keys."); + else if (need_password) + log_info("None of the supplied plaintext passwords unlock the user record's hashed passwords."); + else + log_info("None of the supplied plaintext passwords unlock the user record's hashed recovery keys."); + + /* Second, test cached PKCS#11 passwords */ + for (size_t n = 0; n < h->n_pkcs11_encrypted_key; n++) + STRV_FOREACH(pp, cache->pkcs11_passwords) { + r = test_password_one(h->pkcs11_encrypted_key[n].hashed_password, *pp); + if (r < 0) + return log_error_errno(r, "Failed to check supplied PKCS#11 password: %m"); + if (r > 0) { + log_info("Previously acquired PKCS#11 password unlocks user record."); + return 1; + } + } + + /* Third, test cached FIDO2 passwords */ + for (size_t n = 0; n < h->n_fido2_hmac_salt; n++) + /* See if any of the previously calculated passwords work */ + STRV_FOREACH(pp, cache->fido2_passwords) { + r = test_password_one(h->fido2_hmac_salt[n].hashed_password, *pp); + if (r < 0) + return log_error_errno(r, "Failed to check supplied FIDO2 password: %m"); + if (r > 0) { + log_info("Previously acquired FIDO2 password unlocks user record."); + return 1; + } + } + + /* Fourth, let's see if any of the PKCS#11 security tokens are plugged in and help us */ + for (size_t n = 0; n < h->n_pkcs11_encrypted_key; n++) { +#if HAVE_P11KIT + _cleanup_(pkcs11_callback_data_release) struct pkcs11_callback_data data = { + .user_record = h, + .secret = secret, + .encrypted_key = h->pkcs11_encrypted_key + n, + }; + + r = pkcs11_find_token(data.encrypted_key->uri, pkcs11_callback, &data); + switch (r) { + case -EAGAIN: + need_token = true; + break; + case -ENOANO: + need_pin = true; + break; + case -ERFKILL: + need_protected_authentication_path_permitted = true; + break; + case -EOWNERDEAD: + pin_locked = true; + break; + case -ENOLCK: + pin_incorrect = true; + break; + case -ETOOMANYREFS: + pin_incorrect = pin_incorrect_few_tries_left = true; + break; + case -EUCLEAN: + pin_incorrect = pin_incorrect_few_tries_left = pin_incorrect_one_try_left = true; + break; + default: + if (r < 0) + return r; + + r = test_password_one(data.encrypted_key->hashed_password, data.decrypted_password); + if (r < 0) + return log_error_errno(r, "Failed to test PKCS#11 password: %m"); + if (r == 0) + return log_error_errno(SYNTHETIC_ERRNO(EPERM), "Configured PKCS#11 security token %s does not decrypt encrypted key correctly.", data.encrypted_key->uri); + + log_info("Decrypted password from PKCS#11 security token %s unlocks user record.", data.encrypted_key->uri); + + r = strv_extend(&cache->pkcs11_passwords, data.decrypted_password); + if (r < 0) + return log_oom(); + + return 1; + } +#else + need_token = true; + break; +#endif + } + + /* Fifth, let's see if any of the FIDO2 security tokens are plugged in and help us */ + for (size_t n = 0; n < h->n_fido2_hmac_salt; n++) { +#if HAVE_LIBFIDO2 + _cleanup_(erase_and_freep) char *decrypted_password = NULL; + + r = fido2_use_token(h, secret, h->fido2_hmac_salt + n, &decrypted_password); + switch (r) { + case -EAGAIN: + need_token = true; + break; + case -ENOANO: + need_pin = true; + break; + case -EOWNERDEAD: + pin_locked = true; + break; + case -ENOLCK: + pin_incorrect = true; + break; + case -EMEDIUMTYPE: + need_user_presence_permitted = true; + break; + case -ENOCSI: + need_user_verification_permitted = true; + break; + case -ENOSTR: + token_action_timeout = true; + break; + default: + if (r < 0) + return r; + + r = test_password_one(h->fido2_hmac_salt[n].hashed_password, decrypted_password); + if (r < 0) + return log_error_errno(r, "Failed to test FIDO2 password: %m"); + if (r == 0) + return log_error_errno(SYNTHETIC_ERRNO(EPERM), "Configured FIDO2 security token does not decrypt encrypted key correctly."); + + log_info("Decrypted password from FIDO2 security token unlocks user record."); + + r = strv_extend(&cache->fido2_passwords, decrypted_password); + if (r < 0) + return log_oom(); + + return 1; + } +#else + need_token = true; + break; +#endif + } + + /* Ordered by "relevance", i.e. the most "important" or "interesting" error condition is returned. */ + if (pin_incorrect_one_try_left) + return -EUCLEAN; + if (pin_incorrect_few_tries_left) + return -ETOOMANYREFS; + if (pin_incorrect) + return -ENOLCK; + if (pin_locked) + return -EOWNERDEAD; + if (token_action_timeout) + return -ENOSTR; + if (need_protected_authentication_path_permitted) + return -ERFKILL; + if (need_user_presence_permitted) + return -EMEDIUMTYPE; + if (need_user_verification_permitted) + return -ENOCSI; + if (need_pin) + return -ENOANO; + if (need_token) + return -EBADSLT; + if (need_password) + return -ENOKEY; + if (need_recovery_key) + return -EREMOTEIO; + + /* Hmm, this means neither PCKS#11/FIDO2 nor classic hashed passwords or recovery keys were supplied, + * we cannot authenticate this reasonably */ + if (strict_verify) + return log_debug_errno(SYNTHETIC_ERRNO(EKEYREVOKED), + "No hashed passwords, no recovery keys and no PKCS#11/FIDO2 tokens defined, cannot authenticate user record, refusing."); + + /* If strict verification is off this means we are possibly in the case where we encountered an + * unfixated record, i.e. a synthetic one that accordingly lacks any authentication data. In this + * case, allow the authentication to pass for now, so that the second (or third) authentication level + * (the ones of the user record in the LUKS header or inside the home directory) will then catch + * invalid passwords. The second/third authentication always runs in strict verification mode. */ + log_debug("No hashed passwords, not recovery keys and no PKCS#11 tokens defined in record, cannot authenticate user record. " + "Deferring to embedded user record."); + return 0; +} + +static void drop_caches_now(void) { + int r; + + /* Drop file system caches now. See https://docs.kernel.org/admin-guide/sysctl/vm.html + * for details. We write "2" into /proc/sys/vm/drop_caches to ensure dentries/inodes are flushed, but + * not more. */ + + r = write_string_file("/proc/sys/vm/drop_caches", "2\n", WRITE_STRING_FILE_DISABLE_BUFFER); + if (r < 0) + log_warning_errno(r, "Failed to drop caches, ignoring: %m"); + else + log_debug("Dropped caches."); +} + +int home_setup_undo_mount(HomeSetup *setup, int level) { + int r; + + assert(setup); + + if (!setup->undo_mount) + return 0; + + r = umount_recursive(HOME_RUNTIME_WORK_DIR, 0); + if (r < 0) { + if (level >= LOG_DEBUG) /* umount_recursive() does debug level logging anyway, no need to + * repeat that here */ + return r; + + /* If a higher log level is requested, the generate a non-debug message here too. */ + return log_full_errno(level, r, "Failed to unmount mount tree below %s: %m", HOME_RUNTIME_WORK_DIR); + } + + setup->undo_mount = false; + return 1; +} + +int home_setup_undo_dm(HomeSetup *setup, int level) { + int r, ret; + + assert(setup); + + if (setup->undo_dm) { + assert(setup->crypt_device); + assert(setup->dm_name); + + r = sym_crypt_deactivate_by_name(setup->crypt_device, setup->dm_name, 0); + if (r < 0) + return log_full_errno(level, r, "Failed to deactivate LUKS device: %m"); + + /* In case the device was already remove asynchronously by an early unmount via the deferred + * remove logic, let's wait for it */ + (void) wait_for_block_device_gone(setup, USEC_PER_SEC * 30); + + setup->undo_dm = false; + ret = 1; + } else + ret = 0; + + if (setup->crypt_device) { + sym_crypt_free(setup->crypt_device); + setup->crypt_device = NULL; + } + + return ret; +} + +int keyring_unlink(key_serial_t k) { + + if (k == -1) /* already invalidated? */ + return -1; + + if (keyctl(KEYCTL_UNLINK, k, KEY_SPEC_SESSION_KEYRING, 0, 0) < 0) + log_debug_errno(errno, "Failed to unlink key from session kernel keyring, ignoring: %m"); + + return -1; /* Always return the key_serial_t value for "invalid" */ +} + +static int keyring_flush(UserRecord *h) { + _cleanup_free_ char *name = NULL; + long serial; + + assert(h); + + name = strjoin("homework-user-", h->user_name); + if (!name) + return log_oom(); + + serial = keyctl(KEYCTL_SEARCH, (unsigned long) KEY_SPEC_SESSION_KEYRING, (unsigned long) "user", (unsigned long) name, 0); + if (serial == -1) + return log_debug_errno(errno, "Failed to find kernel keyring entry for user, ignoring: %m"); + + return keyring_unlink(serial); +} + +int home_setup_done(HomeSetup *setup) { + int r = 0, q; + + assert(setup); + + if (setup->root_fd >= 0) { + if (setup->do_offline_fitrim) { + q = run_fitrim(setup->root_fd); + if (q < 0) + r = q; + } + + if (syncfs(setup->root_fd) < 0) + log_debug_errno(errno, "Failed to synchronize home directory, ignoring: %m"); + + setup->root_fd = safe_close(setup->root_fd); + } + + q = home_setup_undo_mount(setup, LOG_DEBUG); + if (q < 0) + r = q; + + q = home_setup_undo_dm(setup, LOG_DEBUG); + if (q < 0) + r = q; + + if (setup->image_fd >= 0) { + if (setup->do_offline_fallocate) { + q = run_fallocate(setup->image_fd, NULL); + if (q < 0) + r = q; + } + + if (setup->do_mark_clean) { + q = run_mark_dirty(setup->image_fd, false); + if (q < 0) + r = q; + } + + setup->image_fd = safe_close(setup->image_fd); + } + + if (setup->temporary_image_path) { + if (unlink(setup->temporary_image_path) < 0) + log_debug_errno(errno, "Failed to remove temporary image file '%s', ignoring: %m", + setup->temporary_image_path); + + setup->temporary_image_path = mfree(setup->temporary_image_path); + } + + setup->key_serial = keyring_unlink(setup->key_serial); + + setup->undo_mount = false; + setup->undo_dm = false; + setup->do_offline_fitrim = false; + setup->do_offline_fallocate = false; + setup->do_mark_clean = false; + + setup->dm_name = mfree(setup->dm_name); + setup->dm_node = mfree(setup->dm_node); + + setup->loop = loop_device_unref(setup->loop); + + setup->volume_key = erase_and_free(setup->volume_key); + setup->volume_key_size = 0; + + if (setup->do_drop_caches) + drop_caches_now(); + + setup->mount_suffix = mfree(setup->mount_suffix); + + return r; +} + +int home_setup( + UserRecord *h, + HomeSetupFlags flags, + HomeSetup *setup, + PasswordCache *cache, + UserRecord **ret_header_home) { + + int r; + + assert(h); + assert(setup); + assert(!setup->loop); + assert(!setup->crypt_device); + assert(setup->root_fd < 0); + assert(!setup->undo_dm); + assert(!setup->undo_mount); + + /* Makes a home directory accessible (through the root_fd file descriptor, not by path!). */ + + if (!FLAGS_SET(flags, HOME_SETUP_ALREADY_ACTIVATED)) /* If we set up the directory, we should also drop caches once we are done */ + setup->do_drop_caches = setup->do_drop_caches || user_record_drop_caches(h); + + switch (user_record_storage(h)) { + + case USER_LUKS: + return home_setup_luks(h, flags, NULL, setup, cache, ret_header_home); + + case USER_SUBVOLUME: + case USER_DIRECTORY: + r = home_setup_directory(h, setup); + break; + + case USER_FSCRYPT: + r = home_setup_fscrypt(h, setup, cache); + break; + + case USER_CIFS: + r = home_setup_cifs(h, flags, setup); + break; + + default: + return log_error_errno(SYNTHETIC_ERRNO(ENOLINK), "Processing home directories of type '%s' currently not supported.", user_storage_to_string(user_record_storage(h))); + } + + if (r < 0) + return r; + + if (ret_header_home) + *ret_header_home = NULL; + + return r; +} + +int home_sync_and_statfs(int root_fd, struct statfs *ret) { + assert(root_fd >= 0); + + /* Let's sync this to disk, so that the disk space reported by fstatfs() below is accurate (for file + * systems such as btrfs where this is determined lazily). */ + + if (syncfs(root_fd) < 0) + return log_error_errno(errno, "Failed to synchronize file system: %m"); + + if (ret) + if (fstatfs(root_fd, ret) < 0) + return log_error_errno(errno, "Failed to statfs() file system: %m"); + + log_info("Synchronized disk."); + + return 0; +} + +static int read_identity_file(int root_fd, JsonVariant **ret) { + _cleanup_(fclosep) FILE *identity_file = NULL; + _cleanup_close_ int identity_fd = -1; + unsigned line, column; + int r; + + assert(root_fd >= 0); + assert(ret); + + identity_fd = openat(root_fd, ".identity", O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW|O_NONBLOCK); + if (identity_fd < 0) + return log_error_errno(errno, "Failed to open .identity file in home directory: %m"); + + r = fd_verify_regular(identity_fd); + if (r < 0) + return log_error_errno(r, "Embedded identity file is not a regular file, refusing: %m"); + + identity_file = take_fdopen(&identity_fd, "r"); + if (!identity_file) + return log_oom(); + + r = json_parse_file(identity_file, ".identity", JSON_PARSE_SENSITIVE, ret, &line, &column); + if (r < 0) + return log_error_errno(r, "[.identity:%u:%u] Failed to parse JSON data: %m", line, column); + + log_info("Read embedded .identity file."); + + return 0; +} + +static int write_identity_file(int root_fd, JsonVariant *v, uid_t uid) { + _cleanup_(json_variant_unrefp) JsonVariant *normalized = NULL; + _cleanup_(fclosep) FILE *identity_file = NULL; + _cleanup_close_ int identity_fd = -1; + _cleanup_free_ char *fn = NULL; + int r; + + assert(root_fd >= 0); + assert(v); + + normalized = json_variant_ref(v); + + r = json_variant_normalize(&normalized); + if (r < 0) + log_warning_errno(r, "Failed to normalize user record, ignoring: %m"); + + r = tempfn_random(".identity", NULL, &fn); + if (r < 0) + return r; + + identity_fd = openat(root_fd, fn, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, 0600); + if (identity_fd < 0) + return log_error_errno(errno, "Failed to create .identity file in home directory: %m"); + + identity_file = take_fdopen(&identity_fd, "w"); + if (!identity_file) { + r = log_oom(); + goto fail; + } + + json_variant_dump(normalized, JSON_FORMAT_PRETTY, identity_file, NULL); + + r = fflush_and_check(identity_file); + if (r < 0) { + log_error_errno(r, "Failed to write .identity file: %m"); + goto fail; + } + + if (fchown(fileno(identity_file), uid, uid) < 0) { + r = log_error_errno(errno, "Failed to change ownership of identity file: %m"); + goto fail; + } + + if (renameat(root_fd, fn, root_fd, ".identity") < 0) { + r = log_error_errno(errno, "Failed to move identity file into place: %m"); + goto fail; + } + + log_info("Wrote embedded .identity file."); + + return 0; + +fail: + (void) unlinkat(root_fd, fn, 0); + return r; +} + +int home_load_embedded_identity( + UserRecord *h, + int root_fd, + UserRecord *header_home, + UserReconcileMode mode, + PasswordCache *cache, + UserRecord **ret_embedded_home, + UserRecord **ret_new_home) { + + _cleanup_(user_record_unrefp) UserRecord *embedded_home = NULL, *intermediate_home = NULL, *new_home = NULL; + _cleanup_(json_variant_unrefp) JsonVariant *v = NULL; + int r; + + assert(h); + assert(root_fd >= 0); + + r = read_identity_file(root_fd, &v); + if (r < 0) + return r; + + embedded_home = user_record_new(); + if (!embedded_home) + return log_oom(); + + r = user_record_load(embedded_home, v, USER_RECORD_LOAD_EMBEDDED|USER_RECORD_PERMISSIVE); + if (r < 0) + return r; + + if (!user_record_compatible(h, embedded_home)) + return log_error_errno(SYNTHETIC_ERRNO(EREMCHG), "Embedded home record not compatible with host record, refusing."); + + /* Insist that credentials the user supplies also unlocks any embedded records. */ + r = user_record_authenticate(embedded_home, h, cache, /* strict_verify= */ true); + if (r < 0) + return r; + assert(r > 0); /* Insist that a password was verified */ + + /* At this point we have three records to deal with: + * + * · The record we got passed from the host + * · The record included in the LUKS header (only if LUKS is used) + * · The record in the home directory itself (~.identity) + * + * Now we have to reconcile all three, and let the newest one win. */ + + if (header_home) { + /* Note we relax the requirements here. Instead of insisting that the host record is strictly + * newer, let's also be OK if its equally new. If it is, we'll however insist that the + * embedded record must be newer, so that we update at least one of the two. */ + + r = user_record_reconcile(h, header_home, mode == USER_RECONCILE_REQUIRE_NEWER ? USER_RECONCILE_REQUIRE_NEWER_OR_EQUAL : mode, &intermediate_home); + if (r == -EREMCHG) /* this was supposed to be checked earlier already, but let's check this again */ + return log_error_errno(r, "Identity stored on host and in header don't match, refusing."); + if (r == -ESTALE) + return log_error_errno(r, "Embedded identity record is newer than supplied record, refusing."); + if (r < 0) + return log_error_errno(r, "Failed to reconcile host and header identities: %m"); + if (r == USER_RECONCILE_EMBEDDED_WON) + log_info("Reconciling header user identity completed (header version was newer)."); + else if (r == USER_RECONCILE_HOST_WON) { + log_info("Reconciling header user identity completed (host version was newer)."); + + if (mode == USER_RECONCILE_REQUIRE_NEWER) /* Host version is newer than the header + * version, hence we'll update + * something. This means we can relax the + * requirements on the embedded + * identity. */ + mode = USER_RECONCILE_REQUIRE_NEWER_OR_EQUAL; + } else { + assert(r == USER_RECONCILE_IDENTICAL); + log_info("Reconciling user identities completed (host and header version were identical)."); + } + + h = intermediate_home; + } + + r = user_record_reconcile(h, embedded_home, mode, &new_home); + if (r == -EREMCHG) + return log_error_errno(r, "Identity stored on host and in home don't match, refusing."); + if (r == -ESTALE) + return log_error_errno(r, "Embedded identity record is equally new or newer than supplied record, refusing."); + if (r < 0) + return log_error_errno(r, "Failed to reconcile host and embedded identities: %m"); + if (r == USER_RECONCILE_EMBEDDED_WON) + log_info("Reconciling embedded user identity completed (embedded version was newer)."); + else if (r == USER_RECONCILE_HOST_WON) + log_info("Reconciling embedded user identity completed (host version was newer)."); + else { + assert(r == USER_RECONCILE_IDENTICAL); + log_info("Reconciling embedded user identity completed (host and embedded version were identical)."); + } + + if (ret_embedded_home) + *ret_embedded_home = TAKE_PTR(embedded_home); + + if (ret_new_home) + *ret_new_home = TAKE_PTR(new_home); + + return 0; +} + +int home_store_embedded_identity(UserRecord *h, int root_fd, uid_t uid, UserRecord *old_home) { + _cleanup_(user_record_unrefp) UserRecord *embedded = NULL; + int r; + + assert(h); + assert(root_fd >= 0); + assert(uid_is_valid(uid)); + + r = user_record_clone(h, USER_RECORD_EXTRACT_EMBEDDED|USER_RECORD_PERMISSIVE, &embedded); + if (r < 0) + return log_error_errno(r, "Failed to determine new embedded record: %m"); + + if (old_home && user_record_equal(old_home, embedded)) { + log_debug("Not updating embedded home record."); + return 0; + } + + /* The identity has changed, let's update it in the image */ + r = write_identity_file(root_fd, embedded->json, h->uid); + if (r < 0) + return r; + + return 1; +} + +static const char *file_system_type_fd(int fd) { + struct statfs sfs; + + assert(fd >= 0); + + if (fstatfs(fd, &sfs) < 0) { + log_debug_errno(errno, "Failed to statfs(): %m"); + return NULL; + } + + return fs_type_to_string(sfs.f_type); +} + +int home_extend_embedded_identity(UserRecord *h, UserRecord *used, HomeSetup *setup) { + int r; + + assert(h); + assert(used); + assert(setup); + + r = user_record_add_binding( + h, + user_record_storage(used), + user_record_image_path(used), + setup->found_partition_uuid, + setup->found_luks_uuid, + setup->found_fs_uuid, + setup->crypt_device ? sym_crypt_get_cipher(setup->crypt_device) : NULL, + setup->crypt_device ? sym_crypt_get_cipher_mode(setup->crypt_device) : NULL, + setup->crypt_device ? luks_volume_key_size_convert(setup->crypt_device) : UINT64_MAX, + file_system_type_fd(setup->root_fd), + user_record_home_directory(used), + used->uid, + (gid_t) used->uid); + if (r < 0) + return log_error_errno(r, "Failed to update binding in record: %m"); + + return 0; +} + +static int chown_recursive_directory(int root_fd, uid_t uid) { + int r; + + assert(root_fd >= 0); + assert(uid_is_valid(uid)); + + r = fd_chown_recursive(root_fd, uid, (gid_t) uid, 0777); + if (r < 0) + return log_error_errno(r, "Failed to change ownership of files and directories: %m"); + if (r == 0) + log_info("Recursive changing of ownership not necessary, skipped."); + else + log_info("Recursive changing of ownership completed."); + + return 0; +} + +int home_maybe_shift_uid( + UserRecord *h, + HomeSetupFlags flags, + HomeSetup *setup) { + + _cleanup_close_ int mount_fd = -1; + struct stat st; + + assert(h); + assert(setup); + assert(setup->root_fd >= 0); + + /* If the home dir is already activated, then the UID shift is already applied. */ + if (FLAGS_SET(flags, HOME_SETUP_ALREADY_ACTIVATED)) + return 0; + + if (fstat(setup->root_fd, &st) < 0) + return log_error_errno(errno, "Failed to stat() home directory: %m"); + + /* Let's shift UIDs of this mount. Hopefully this makes the later chowning unnecessary. (Note that we + * also prefer to do UID mapping even if the UID already matches our goal UID. That's because we want + * to leave UIDs in the homed managed range unmapped.) */ + (void) home_shift_uid(setup->root_fd, NULL, st.st_uid, h->uid, &mount_fd); + + /* If this worked, then we'll have a reference to the mount now, which we can also use like an O_PATH + * fd to the new dir. Let's convert it into a proper O_DIRECTORY fd. */ + if (mount_fd >= 0) { + safe_close(setup->root_fd); + + setup->root_fd = fd_reopen(mount_fd, O_RDONLY|O_CLOEXEC|O_DIRECTORY); + if (setup->root_fd < 0) + return log_error_errno(setup->root_fd, "Failed to convert mount fd into regular directory fd: %m"); + } + + return 0; +} + +int home_refresh( + UserRecord *h, + HomeSetupFlags flags, + HomeSetup *setup, + UserRecord *header_home, + PasswordCache *cache, + struct statfs *ret_statfs, + UserRecord **ret_new_home) { + + _cleanup_(user_record_unrefp) UserRecord *embedded_home = NULL, *new_home = NULL; + int r; + + assert(h); + assert(setup); + assert(ret_new_home); + + /* When activating a home directory, does the identity work: loads the identity from the $HOME + * directory, reconciles it with our idea, chown()s everything. */ + + r = home_load_embedded_identity(h, setup->root_fd, header_home, USER_RECONCILE_ANY, cache, &embedded_home, &new_home); + if (r < 0) + return r; + + r = home_maybe_shift_uid(h, flags, setup); + if (r < 0) + return r; + + r = home_store_header_identity_luks(new_home, setup, header_home); + if (r < 0) + return r; + + r = home_store_embedded_identity(new_home, setup->root_fd, h->uid, embedded_home); + if (r < 0) + return r; + + r = chown_recursive_directory(setup->root_fd, h->uid); + if (r < 0) + return r; + + r = home_sync_and_statfs(setup->root_fd, ret_statfs); + if (r < 0) + return r; + + *ret_new_home = TAKE_PTR(new_home); + return 0; +} + +static int home_activate(UserRecord *h, UserRecord **ret_home) { + _cleanup_(home_setup_done) HomeSetup setup = HOME_SETUP_INIT; + _cleanup_(user_record_unrefp) UserRecord *new_home = NULL; + _cleanup_(password_cache_free) PasswordCache cache = {}; + HomeSetupFlags flags = 0; + int r; + + assert(h); + + if (!h->user_name) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "User record lacks user name, refusing."); + if (!uid_is_valid(h->uid)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "User record lacks UID, refusing."); + if (!IN_SET(user_record_storage(h), USER_LUKS, USER_DIRECTORY, USER_SUBVOLUME, USER_FSCRYPT, USER_CIFS)) + return log_error_errno(SYNTHETIC_ERRNO(ENOTTY), "Activating home directories of type '%s' currently not supported.", user_storage_to_string(user_record_storage(h))); + + r = user_record_authenticate(h, h, &cache, /* strict_verify= */ false); + if (r < 0) + return r; + + r = user_record_test_home_directory_and_warn(h); + if (r < 0) + return r; + if (r == USER_TEST_MOUNTED) + return log_error_errno(SYNTHETIC_ERRNO(EALREADY), "Home directory %s is already mounted, refusing.", user_record_home_directory(h)); + + r = user_record_test_image_path_and_warn(h); + if (r < 0) + return r; + if (r == USER_TEST_ABSENT) + return log_error_errno(SYNTHETIC_ERRNO(ENOENT), "Image path %s is missing, refusing.", user_record_image_path(h)); + + switch (user_record_storage(h)) { + + case USER_LUKS: + r = home_activate_luks(h, flags, &setup, &cache, &new_home); + if (r < 0) + return r; + + break; + + case USER_SUBVOLUME: + case USER_DIRECTORY: + case USER_FSCRYPT: + r = home_activate_directory(h, flags, &setup, &cache, &new_home); + if (r < 0) + return r; + + break; + + case USER_CIFS: + r = home_activate_cifs(h, flags, &setup, &cache, &new_home); + if (r < 0) + return r; + + break; + + default: + assert_not_reached(); + } + + /* Note that the returned object might either be a reference to an updated version of the existing + * home object, or a reference to a newly allocated home object. The caller has to be able to deal + * with both, and consider the old object out-of-date. */ + if (user_record_equal(h, new_home)) { + *ret_home = NULL; + return 0; /* no identity change */ + } + + *ret_home = TAKE_PTR(new_home); + return 1; /* identity updated */ +} + +static int home_deactivate(UserRecord *h, bool force) { + _cleanup_(home_setup_done) HomeSetup setup = HOME_SETUP_INIT; + _cleanup_(password_cache_free) PasswordCache cache = {}; + bool done = false; + int r; + + assert(h); + + if (!h->user_name) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "User record incomplete, refusing."); + if (!IN_SET(user_record_storage(h), USER_LUKS, USER_DIRECTORY, USER_SUBVOLUME, USER_FSCRYPT, USER_CIFS)) + return log_error_errno(SYNTHETIC_ERRNO(ENOTTY), "Deactivating home directories of type '%s' currently not supported.", user_storage_to_string(user_record_storage(h))); + + r = user_record_test_home_directory_and_warn(h); + if (r < 0) + return r; + if (r == USER_TEST_MOUNTED) { + /* Before we do anything, let's move the home mount away. */ + r = home_unshare_and_mkdir(); + if (r < 0) + return r; + + r = mount_nofollow_verbose(LOG_ERR, user_record_home_directory(h), HOME_RUNTIME_WORK_DIR, NULL, MS_BIND, NULL); + if (r < 0) + return r; + + setup.undo_mount = true; /* remember to unmount the new bind mount from HOME_RUNTIME_WORK_DIR */ + + /* Let's explicitly open the new root fs, using the moved path */ + setup.root_fd = open(HOME_RUNTIME_WORK_DIR, O_RDONLY|O_DIRECTORY|O_CLOEXEC); + if (setup.root_fd < 0) + return log_error_errno(errno, "Failed to open moved home directory: %m"); + + /* Now get rid of the home at its original place (we only keep the bind mount we created above) */ + r = umount_verbose(LOG_ERR, user_record_home_directory(h), UMOUNT_NOFOLLOW | (force ? MNT_FORCE|MNT_DETACH : 0)); + if (r < 0) + return r; + + if (user_record_storage(h) == USER_LUKS) { + /* Automatically shrink on logout if that's enabled. To be able to shrink we need the + * keys to the device. */ + password_cache_load_keyring(h, &cache); + (void) home_trim_luks(h, &setup); + } + + /* Sync explicitly, so that the drop caches logic below can work as documented */ + if (syncfs(setup.root_fd) < 0) + log_debug_errno(errno, "Failed to synchronize home directory, ignoring: %m"); + else + log_info("Syncing completed."); + + if (user_record_storage(h) == USER_LUKS) + (void) home_auto_shrink_luks(h, &setup, &cache); + + setup.root_fd = safe_close(setup.root_fd); + + /* Now get rid of the bind mount, too */ + r = umount_verbose(LOG_ERR, HOME_RUNTIME_WORK_DIR, UMOUNT_NOFOLLOW | (force ? MNT_FORCE|MNT_DETACH : 0)); + if (r < 0) + return r; + + setup.undo_mount = false; /* Remember that the bind mount doesn't need to be unmounted anymore */ + + if (user_record_drop_caches(h)) + setup.do_drop_caches = true; + + log_info("Unmounting completed."); + done = true; + } else + log_info("Directory %s is already unmounted.", user_record_home_directory(h)); + + if (user_record_storage(h) == USER_LUKS) { + r = home_deactivate_luks(h, &setup); + if (r < 0) + return r; + if (r > 0) + done = true; + } + + /* Explicitly flush any per-user key from the keyring */ + (void) keyring_flush(h); + + if (!done) + return log_error_errno(SYNTHETIC_ERRNO(ENOEXEC), "Home is not active."); + + if (setup.do_drop_caches) { + setup.do_drop_caches = false; + drop_caches_now(); + } + + log_info("Everything completed."); + return 0; +} + +static int copy_skel(int root_fd, const char *skel) { + int r; + + assert(root_fd >= 0); + + r = copy_tree_at(AT_FDCWD, skel, root_fd, ".", UID_INVALID, GID_INVALID, COPY_MERGE|COPY_REPLACE); + if (r == -ENOENT) { + log_info("Skeleton directory %s missing, ignoring.", skel); + return 0; + } + if (r < 0) + return log_error_errno(r, "Failed to copy in %s: %m", skel); + + log_info("Copying in %s completed.", skel); + return 0; +} + +static int change_access_mode(int root_fd, mode_t m) { + assert(root_fd >= 0); + + if (fchmod(root_fd, m) < 0) + return log_error_errno(errno, "Failed to change access mode of top-level directory: %m"); + + log_info("Changed top-level directory access mode to 0%o.", m); + return 0; +} + +int home_populate(UserRecord *h, int dir_fd) { + int r; + + assert(h); + assert(dir_fd >= 0); + + r = copy_skel(dir_fd, user_record_skeleton_directory(h)); + if (r < 0) + return r; + + r = home_store_embedded_identity(h, dir_fd, h->uid, NULL); + if (r < 0) + return r; + + r = chown_recursive_directory(dir_fd, h->uid); + if (r < 0) + return r; + + r = change_access_mode(dir_fd, user_record_access_mode(h)); + if (r < 0) + return r; + + return 0; +} + +static int user_record_compile_effective_passwords( + UserRecord *h, + PasswordCache *cache, + char ***ret_effective_passwords) { + + _cleanup_(strv_free_erasep) char **effective = NULL; + size_t n; + int r; + + assert(h); + assert(cache); + + /* We insist on at least one classic hashed password to be defined in addition to any PKCS#11 one, as + * a safe fallback, but also to simplify the password changing algorithm: there we require providing + * the old literal password only (and do not care for the old PKCS#11 token) */ + + if (strv_isempty(h->hashed_password)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "User record has no hashed passwords, refusing."); + + /* Generates the list of plaintext passwords to propagate to LUKS/fscrypt devices, and checks whether + * we have a plaintext password for each hashed one. If we are missing one we'll fail, since we + * couldn't sync fscrypt/LUKS to the login account properly. */ + + STRV_FOREACH(i, h->hashed_password) { + bool found = false; + + log_debug("Looking for plaintext password for: %s", *i); + + /* Let's scan all provided plaintext passwords */ + STRV_FOREACH(j, h->password) { + r = test_password_one(*i, *j); + if (r < 0) + return log_error_errno(r, "Failed to test plaintext password: %m"); + if (r > 0) { + if (ret_effective_passwords) { + r = strv_extend(&effective, *j); + if (r < 0) + return log_oom(); + } + + log_debug("Found literal plaintext password."); + found = true; + break; + } + } + + if (!found) + return log_error_errno(SYNTHETIC_ERRNO(ENOKEY), "Missing plaintext password for defined hashed password"); + } + + for (n = 0; n < h->n_recovery_key; n++) { + bool found = false; + + log_debug("Looking for plaintext recovery key for: %s", h->recovery_key[n].hashed_password); + + STRV_FOREACH(j, h->password) { + _cleanup_(erase_and_freep) char *mangled = NULL; + const char *p; + + if (streq(h->recovery_key[n].type, "modhex64")) { + + r = normalize_recovery_key(*j, &mangled); + if (r == -EINVAL) /* Not properly formatted, probably a regular password. */ + continue; + if (r < 0) + return log_error_errno(r, "Failed to normalize recovery key: %m"); + + p = mangled; + } else + p = *j; + + r = test_password_one(h->recovery_key[n].hashed_password, p); + if (r < 0) + return log_error_errno(r, "Failed to test plaintext recovery key: %m"); + if (r > 0) { + if (ret_effective_passwords) { + r = strv_extend(&effective, p); + if (r < 0) + return log_oom(); + } + + log_debug("Found plaintext recovery key."); + found = true; + break; + } + } + + if (!found) + return log_error_errno(SYNTHETIC_ERRNO(EREMOTEIO), "Missing plaintext recovery key for defined recovery key"); + } + + for (n = 0; n < h->n_pkcs11_encrypted_key; n++) { +#if HAVE_P11KIT + _cleanup_(pkcs11_callback_data_release) struct pkcs11_callback_data data = { + .user_record = h, + .secret = h, + .encrypted_key = h->pkcs11_encrypted_key + n, + }; + + r = pkcs11_find_token(data.encrypted_key->uri, pkcs11_callback, &data); + if (r == -EAGAIN) + return -EBADSLT; + if (r < 0) + return r; + + r = test_password_one(data.encrypted_key->hashed_password, data.decrypted_password); + if (r < 0) + return log_error_errno(r, "Failed to test PKCS#11 password: %m"); + if (r == 0) + return log_error_errno(SYNTHETIC_ERRNO(EPERM), "Decrypted password from token is not correct, refusing."); + + if (ret_effective_passwords) { + r = strv_extend(&effective, data.decrypted_password); + if (r < 0) + return log_oom(); + } + + r = strv_extend(&cache->pkcs11_passwords, data.decrypted_password); + if (r < 0) + return log_oom(); +#else + return -EBADSLT; +#endif + } + + for (n = 0; n < h->n_fido2_hmac_salt; n++) { +#if HAVE_LIBFIDO2 + _cleanup_(erase_and_freep) char *decrypted_password = NULL; + + r = fido2_use_token(h, h, h->fido2_hmac_salt + n, &decrypted_password); + if (r < 0) + return r; + + r = test_password_one(h->fido2_hmac_salt[n].hashed_password, decrypted_password); + if (r < 0) + return log_error_errno(r, "Failed to test FIDO2 password: %m"); + if (r == 0) + return log_error_errno(SYNTHETIC_ERRNO(EPERM), "Decrypted password from token is not correct, refusing."); + + if (ret_effective_passwords) { + r = strv_extend(&effective, decrypted_password); + if (r < 0) + return log_oom(); + } + + r = strv_extend(&cache->fido2_passwords, decrypted_password); + if (r < 0) + return log_oom(); +#else + return -EBADSLT; +#endif + } + + if (ret_effective_passwords) + *ret_effective_passwords = TAKE_PTR(effective); + + return 0; +} + +static int determine_default_storage(UserStorage *ret) { + UserStorage storage = _USER_STORAGE_INVALID; + const char *e; + int r; + + assert(ret); + + /* homed tells us via an environment variable which default storage to use */ + e = getenv("SYSTEMD_HOME_DEFAULT_STORAGE"); + if (e) { + storage = user_storage_from_string(e); + if (storage < 0) + log_warning("$SYSTEMD_HOME_DEFAULT_STORAGE set to invalid storage type, ignoring: %s", e); + else { + log_info("Using configured default storage '%s'.", user_storage_to_string(storage)); + *ret = storage; + return 0; + } + } + + /* When neither user nor admin specified the storage type to use, fix it to be LUKS — unless we run + * in a container where loopback devices and LUKS/DM are not available. Also, if /home is encrypted + * anyway, let's avoid duplicate encryption. Note that we typically default to the assumption of + * "classic" storage for most operations. However, if we create a new home, then let's user LUKS if + * nothing is specified. */ + + r = detect_container(); + if (r < 0) + return log_error_errno(r, "Failed to determine whether we are in a container: %m"); + if (r == 0) { + r = path_is_encrypted(get_home_root()); + if (r > 0) + log_info("%s is encrypted, not using '%s' storage, in order to avoid double encryption.", get_home_root(), user_storage_to_string(USER_LUKS)); + else { + if (r < 0) + log_warning_errno(r, "Failed to determine if %s is encrypted, ignoring: %m", get_home_root()); + + r = dlopen_cryptsetup(); + if (r < 0) + log_info("Not using '%s' storage, since libcryptsetup could not be loaded.", user_storage_to_string(USER_LUKS)); + else { + log_info("Using automatic default storage of '%s'.", user_storage_to_string(USER_LUKS)); + *ret = USER_LUKS; + return 0; + } + } + } else + log_info("Running in container, not using '%s' storage.", user_storage_to_string(USER_LUKS)); + + r = path_is_fs_type(get_home_root(), BTRFS_SUPER_MAGIC); + if (r < 0) + log_warning_errno(r, "Failed to determine file system of %s, ignoring: %m", get_home_root()); + if (r > 0) { + log_info("%s is on btrfs, using '%s' as storage.", get_home_root(), user_storage_to_string(USER_SUBVOLUME)); + *ret = USER_SUBVOLUME; + } else { + log_info("%s is on simple file system, using '%s' as storage.", get_home_root(), user_storage_to_string(USER_DIRECTORY)); + *ret = USER_DIRECTORY; + } + + return 0; +} + +static int home_create(UserRecord *h, UserRecord **ret_home) { + _cleanup_(strv_free_erasep) char **effective_passwords = NULL; + _cleanup_(home_setup_done) HomeSetup setup = HOME_SETUP_INIT; + _cleanup_(user_record_unrefp) UserRecord *new_home = NULL; + _cleanup_(password_cache_free) PasswordCache cache = {}; + UserStorage new_storage = _USER_STORAGE_INVALID; + const char *new_fs = NULL; + int r; + + assert(h); + + if (!h->user_name) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "User record lacks name, refusing."); + if (!uid_is_valid(h->uid)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "User record lacks UID, refusing."); + + r = user_record_compile_effective_passwords(h, &cache, &effective_passwords); + if (r < 0) + return r; + + r = user_record_test_home_directory_and_warn(h); + if (r < 0) + return r; + if (r != USER_TEST_ABSENT) + return log_error_errno(SYNTHETIC_ERRNO(EEXIST), "Home directory %s already exists, refusing.", user_record_home_directory(h)); + + if (h->storage < 0) { + r = determine_default_storage(&new_storage); + if (r < 0) + return r; + } + + if ((h->storage == USER_LUKS || + (h->storage < 0 && new_storage == USER_LUKS)) && + !h->file_system_type) + new_fs = getenv("SYSTEMD_HOME_DEFAULT_FILE_SYSTEM_TYPE"); + + if (new_storage >= 0 || new_fs) { + r = user_record_add_binding( + h, + new_storage, + NULL, + SD_ID128_NULL, + SD_ID128_NULL, + SD_ID128_NULL, + NULL, + NULL, + UINT64_MAX, + new_fs, + NULL, + UID_INVALID, + GID_INVALID); + if (r < 0) + return log_error_errno(r, "Failed to change storage type to LUKS: %m"); + } + + r = user_record_test_image_path_and_warn(h); + if (r < 0) + return r; + if (!IN_SET(r, USER_TEST_ABSENT, USER_TEST_UNDEFINED, USER_TEST_MAYBE)) + return log_error_errno(SYNTHETIC_ERRNO(EEXIST), "Image path %s already exists, refusing.", user_record_image_path(h)); + + switch (user_record_storage(h)) { + + case USER_LUKS: + r = home_create_luks(h, &setup, &cache, effective_passwords, &new_home); + break; + + case USER_DIRECTORY: + case USER_SUBVOLUME: + r = home_create_directory_or_subvolume(h, &setup, &new_home); + break; + + case USER_FSCRYPT: + r = home_create_fscrypt(h, &setup, effective_passwords, &new_home); + break; + + case USER_CIFS: + r = home_create_cifs(h, &setup, &new_home); + break; + + default: + return log_error_errno(SYNTHETIC_ERRNO(ENOTTY), + "Creating home directories of type '%s' currently not supported.", user_storage_to_string(user_record_storage(h))); + } + if (r < 0) + return r; + + if (user_record_equal(h, new_home)) { + *ret_home = NULL; + return 0; + } + + *ret_home = TAKE_PTR(new_home); + return 1; +} + +static int home_remove(UserRecord *h) { + bool deleted = false; + const char *ip, *hd; + int r; + + assert(h); + + if (!h->user_name) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "User record lacks user name, refusing."); + if (!IN_SET(user_record_storage(h), USER_LUKS, USER_DIRECTORY, USER_SUBVOLUME, USER_FSCRYPT, USER_CIFS)) + return log_error_errno(SYNTHETIC_ERRNO(ENOTTY), "Removing home directories of type '%s' currently not supported.", user_storage_to_string(user_record_storage(h))); + + hd = user_record_home_directory(h); + + r = user_record_test_home_directory_and_warn(h); + if (r < 0) + return r; + if (r == USER_TEST_MOUNTED) + return log_error_errno(SYNTHETIC_ERRNO(EBUSY), "Directory %s is still mounted, refusing.", hd); + + assert(hd); + + r = user_record_test_image_path_and_warn(h); + if (r < 0) + return r; + + ip = user_record_image_path(h); + + switch (user_record_storage(h)) { + + case USER_LUKS: { + struct stat st; + + assert(ip); + + if (stat(ip, &st) < 0) { + if (errno != ENOENT) + return log_error_errno(errno, "Failed to stat() %s: %m", ip); + + } else { + if (S_ISREG(st.st_mode)) { + if (unlink(ip) < 0) { + if (errno != ENOENT) + return log_error_errno(errno, "Failed to remove %s: %m", ip); + } else { + _cleanup_free_ char *parent = NULL; + + deleted = true; + + r = path_extract_directory(ip, &parent); + if (r < 0) + log_debug_errno(r, "Failed to determine parent directory of '%s': %m", ip); + else { + r = fsync_path_at(AT_FDCWD, parent); + if (r < 0) + log_debug_errno(r, "Failed to synchronize disk after deleting '%s', ignoring: %m", ip); + } + } + + } else if (S_ISBLK(st.st_mode)) + log_info("Not removing file system on block device %s.", ip); + else + return log_error_errno(SYNTHETIC_ERRNO(ENOTBLK), "Image file %s is neither block device, nor regular, refusing removal.", ip); + } + + break; + } + + case USER_SUBVOLUME: + case USER_DIRECTORY: + case USER_FSCRYPT: + assert(ip); + + r = rm_rf(ip, REMOVE_ROOT|REMOVE_PHYSICAL|REMOVE_SUBVOLUME|REMOVE_SYNCFS); + if (r < 0) { + if (r != -ENOENT) + return log_warning_errno(r, "Failed to remove %s: %m", ip); + } else + deleted = true; + + /* If the image path and the home directory are the same invalidate the home directory, so + * that we don't remove it anymore */ + if (path_equal(ip, hd)) + hd = NULL; + + break; + + case USER_CIFS: + /* Nothing else to do here: we won't remove remote stuff. */ + log_info("Not removing home directory on remote server."); + break; + + default: + assert_not_reached(); + } + + if (hd) { + if (rmdir(hd) < 0) { + if (errno != ENOENT) + return log_error_errno(errno, "Failed to remove %s, ignoring: %m", hd); + } else + deleted = true; + } + + if (deleted) { + if (user_record_drop_caches(h)) + drop_caches_now(); + + log_info("Everything completed."); + } else + return log_notice_errno(SYNTHETIC_ERRNO(EALREADY), + "Nothing to remove."); + + return 0; +} + +static int home_validate_update(UserRecord *h, HomeSetup *setup, HomeSetupFlags *flags) { + bool has_mount = false; + int r; + + assert(h); + assert(setup); + + if (!h->user_name) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "User record lacks user name, refusing."); + if (!uid_is_valid(h->uid)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "User record lacks UID, refusing."); + if (!IN_SET(user_record_storage(h), USER_LUKS, USER_DIRECTORY, USER_SUBVOLUME, USER_FSCRYPT, USER_CIFS)) + return log_error_errno(SYNTHETIC_ERRNO(ENOTTY), "Processing home directories of type '%s' currently not supported.", user_storage_to_string(user_record_storage(h))); + + r = user_record_test_home_directory_and_warn(h); + if (r < 0) + return r; + + has_mount = r == USER_TEST_MOUNTED; + + r = user_record_test_image_path_and_warn(h); + if (r < 0) + return r; + if (r == USER_TEST_ABSENT) + return log_error_errno(SYNTHETIC_ERRNO(ENOENT), "Image path %s does not exist", user_record_image_path(h)); + + switch (user_record_storage(h)) { + + case USER_DIRECTORY: + case USER_SUBVOLUME: + case USER_FSCRYPT: + case USER_CIFS: + break; + + case USER_LUKS: { + r = home_get_state_luks(h, setup); + if (r < 0) + return r; + if ((r > 0) != has_mount) + return log_error_errno(SYNTHETIC_ERRNO(EBUSY), "Home mount incompletely set up."); + + break; + } + + default: + assert_not_reached(); + } + + if (flags) + SET_FLAG(*flags, HOME_SETUP_ALREADY_ACTIVATED, has_mount); + + return has_mount; /* return true if the home record is already active */ +} + +static int home_update(UserRecord *h, UserRecord **ret) { + _cleanup_(user_record_unrefp) UserRecord *new_home = NULL, *header_home = NULL, *embedded_home = NULL; + _cleanup_(home_setup_done) HomeSetup setup = HOME_SETUP_INIT; + _cleanup_(password_cache_free) PasswordCache cache = {}; + HomeSetupFlags flags = 0; + int r; + + assert(h); + assert(ret); + + r = user_record_authenticate(h, h, &cache, /* strict_verify= */ true); + if (r < 0) + return r; + assert(r > 0); /* Insist that a password was verified */ + + r = home_validate_update(h, &setup, &flags); + if (r < 0) + return r; + + r = home_setup(h, flags, &setup, &cache, &header_home); + if (r < 0) + return r; + + r = home_load_embedded_identity(h, setup.root_fd, header_home, USER_RECONCILE_REQUIRE_NEWER, &cache, &embedded_home, &new_home); + if (r < 0) + return r; + + r = home_maybe_shift_uid(h, flags, &setup); + if (r < 0) + return r; + + r = home_store_header_identity_luks(new_home, &setup, header_home); + if (r < 0) + return r; + + r = home_store_embedded_identity(new_home, setup.root_fd, h->uid, embedded_home); + if (r < 0) + return r; + + r = home_extend_embedded_identity(new_home, h, &setup); + if (r < 0) + return r; + + r = home_sync_and_statfs(setup.root_fd, NULL); + if (r < 0) + return r; + + r = home_setup_done(&setup); + if (r < 0) + return r; + + log_info("Everything completed."); + + *ret = TAKE_PTR(new_home); + return 0; +} + +static int home_resize(UserRecord *h, bool automatic, UserRecord **ret) { + _cleanup_(home_setup_done) HomeSetup setup = HOME_SETUP_INIT; + _cleanup_(password_cache_free) PasswordCache cache = {}; + HomeSetupFlags flags = 0; + int r; + + assert(h); + assert(ret); + + if (h->disk_size == UINT64_MAX) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "No target size specified, refusing."); + + if (automatic) + /* In automatic mode don't want to ask the user for the password, hence load it from the kernel keyring */ + password_cache_load_keyring(h, &cache); + else { + /* In manual mode let's ensure the user is fully authenticated */ + r = user_record_authenticate(h, h, &cache, /* strict_verify= */ true); + if (r < 0) + return r; + assert(r > 0); /* Insist that a password was verified */ + } + + r = home_validate_update(h, &setup, &flags); + if (r < 0) + return r; + + /* In automatic mode let's skip syncing identities, because we can't validate them, since we can't + * ask the user for reauthentication */ + if (automatic) + flags |= HOME_SETUP_RESIZE_DONT_SYNC_IDENTITIES; + + switch (user_record_storage(h)) { + + case USER_LUKS: + return home_resize_luks(h, flags, &setup, &cache, ret); + + case USER_DIRECTORY: + case USER_SUBVOLUME: + case USER_FSCRYPT: + return home_resize_directory(h, flags, &setup, &cache, ret); + + default: + return log_error_errno(SYNTHETIC_ERRNO(ENOTTY), "Resizing home directories of type '%s' currently not supported.", user_storage_to_string(user_record_storage(h))); + } +} + +static int home_passwd(UserRecord *h, UserRecord **ret_home) { + _cleanup_(user_record_unrefp) UserRecord *header_home = NULL, *embedded_home = NULL, *new_home = NULL; + _cleanup_(strv_free_erasep) char **effective_passwords = NULL; + _cleanup_(home_setup_done) HomeSetup setup = HOME_SETUP_INIT; + _cleanup_(password_cache_free) PasswordCache cache = {}; + HomeSetupFlags flags = 0; + int r; + + assert(h); + assert(ret_home); + + if (!IN_SET(user_record_storage(h), USER_LUKS, USER_DIRECTORY, USER_SUBVOLUME, USER_FSCRYPT)) + return log_error_errno(SYNTHETIC_ERRNO(ENOTTY), "Changing password of home directories of type '%s' currently not supported.", user_storage_to_string(user_record_storage(h))); + + r = user_record_compile_effective_passwords(h, &cache, &effective_passwords); + if (r < 0) + return r; + + r = home_validate_update(h, &setup, &flags); + if (r < 0) + return r; + + r = home_setup(h, flags, &setup, &cache, &header_home); + if (r < 0) + return r; + + r = home_load_embedded_identity(h, setup.root_fd, header_home, USER_RECONCILE_REQUIRE_NEWER_OR_EQUAL, &cache, &embedded_home, &new_home); + if (r < 0) + return r; + + r = home_maybe_shift_uid(h, flags, &setup); + if (r < 0) + return r; + + switch (user_record_storage(h)) { + + case USER_LUKS: + r = home_passwd_luks(h, flags, &setup, &cache, effective_passwords); + if (r < 0) + return r; + break; + + case USER_FSCRYPT: + r = home_passwd_fscrypt(h, &setup, &cache, effective_passwords); + if (r < 0) + return r; + break; + + default: + break; + } + + r = home_store_header_identity_luks(new_home, &setup, header_home); + if (r < 0) + return r; + + r = home_store_embedded_identity(new_home, setup.root_fd, h->uid, embedded_home); + if (r < 0) + return r; + + r = home_extend_embedded_identity(new_home, h, &setup); + if (r < 0) + return r; + + r = home_sync_and_statfs(setup.root_fd, NULL); + if (r < 0) + return r; + + r = home_setup_done(&setup); + if (r < 0) + return r; + + log_info("Everything completed."); + + *ret_home = TAKE_PTR(new_home); + return 1; +} + +static int home_inspect(UserRecord *h, UserRecord **ret_home) { + _cleanup_(user_record_unrefp) UserRecord *header_home = NULL, *new_home = NULL; + _cleanup_(home_setup_done) HomeSetup setup = HOME_SETUP_INIT; + _cleanup_(password_cache_free) PasswordCache cache = {}; + HomeSetupFlags flags = 0; + int r; + + assert(h); + assert(ret_home); + + r = user_record_authenticate(h, h, &cache, /* strict_verify= */ false); + if (r < 0) + return r; + + r = home_validate_update(h, &setup, &flags); + if (r < 0) + return r; + + r = home_setup(h, flags, &setup, &cache, &header_home); + if (r < 0) + return r; + + r = home_load_embedded_identity(h, setup.root_fd, header_home, USER_RECONCILE_ANY, &cache, NULL, &new_home); + if (r < 0) + return r; + + r = home_extend_embedded_identity(new_home, h, &setup); + if (r < 0) + return r; + + r = home_setup_done(&setup); + if (r < 0) + return r; + + log_info("Everything completed."); + + *ret_home = TAKE_PTR(new_home); + return 1; +} + +static int home_lock(UserRecord *h) { + _cleanup_(home_setup_done) HomeSetup setup = HOME_SETUP_INIT; + int r; + + assert(h); + + if (!h->user_name) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "User record incomplete, refusing."); + if (user_record_storage(h) != USER_LUKS) + return log_error_errno(SYNTHETIC_ERRNO(ENOTTY), "Locking home directories of type '%s' currently not supported.", user_storage_to_string(user_record_storage(h))); + + r = user_record_test_home_directory_and_warn(h); + if (r < 0) + return r; + if (r != USER_TEST_MOUNTED) + return log_error_errno(SYNTHETIC_ERRNO(ENOEXEC), "Home directory of %s is not mounted, can't lock.", h->user_name); + + r = home_lock_luks(h, &setup); + if (r < 0) + return r; + + log_info("Everything completed."); + return 1; +} + +static int home_unlock(UserRecord *h) { + _cleanup_(home_setup_done) HomeSetup setup = HOME_SETUP_INIT; + _cleanup_(password_cache_free) PasswordCache cache = {}; + int r; + + assert(h); + + if (!h->user_name) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "User record incomplete, refusing."); + if (user_record_storage(h) != USER_LUKS) + return log_error_errno(SYNTHETIC_ERRNO(ENOTTY), "Unlocking home directories of type '%s' currently not supported.", user_storage_to_string(user_record_storage(h))); + + /* Note that we don't check if $HOME is actually mounted, since we want to avoid disk accesses on + * that mount until we have resumed the device. */ + + r = user_record_authenticate(h, h, &cache, /* strict_verify= */ false); + if (r < 0) + return r; + + r = home_unlock_luks(h, &setup, &cache); + if (r < 0) + return r; + + log_info("Everything completed."); + return 1; +} + +static int run(int argc, char *argv[]) { + _cleanup_(user_record_unrefp) UserRecord *home = NULL, *new_home = NULL; + _cleanup_(json_variant_unrefp) JsonVariant *v = NULL; + _cleanup_(fclosep) FILE *opened_file = NULL; + unsigned line = 0, column = 0; + const char *json_path = NULL; + FILE *json_file; + usec_t start; + int r; + + start = now(CLOCK_MONOTONIC); + + log_setup(); + + cryptsetup_enable_logging(NULL); + + umask(0022); + + if (argc < 2 || argc > 3) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "This program takes one or two arguments."); + + if (argc > 2) { + json_path = argv[2]; + + opened_file = fopen(json_path, "re"); + if (!opened_file) + return log_error_errno(errno, "Failed to open %s: %m", json_path); + + json_file = opened_file; + } else { + json_path = "<stdin>"; + json_file = stdin; + } + + r = json_parse_file(json_file, json_path, JSON_PARSE_SENSITIVE, &v, &line, &column); + if (r < 0) + return log_error_errno(r, "[%s:%u:%u] Failed to parse JSON data: %m", json_path, line, column); + + home = user_record_new(); + if (!home) + return log_oom(); + + r = user_record_load(home, v, USER_RECORD_LOAD_FULL|USER_RECORD_LOG|USER_RECORD_PERMISSIVE); + if (r < 0) + return r; + + /* Well known return values of these operations, that systemd-homed knows and converts to proper D-Bus errors: + * + * EMSGSIZE → file systems of this type cannot be shrunk + * ETXTBSY → file systems of this type can only be shrunk offline + * ERANGE → file system size too small + * ENOLINK → system does not support selected storage backend + * EPROTONOSUPPORT → system does not support selected file system + * ENOTTY → operation not support on this storage + * ESOCKTNOSUPPORT → operation not support on this file system + * ENOKEY → password incorrect (or not sufficient, or not supplied) + * EREMOTEIO → recovery key incorrect (or not sufficeint, or not supplied — only if no passwords defined) + * EBADSLT → similar, but PKCS#11 device is defined and might be able to provide password, if it was plugged in which it is not + * ENOANO → suitable PKCS#11/FIDO2 device found, but PIN is missing to unlock it + * ERFKILL → suitable PKCS#11 device found, but OK to ask for on-device interactive authentication not given + * EMEDIUMTYPE → suitable FIDO2 device found, but OK to ask for user presence not given + * ENOCSI → suitable FIDO2 device found, but OK to ask for user verification not given + * ENOSTR → suitable FIDO2 device found, but user didn't react to action request on token quickly enough + * EOWNERDEAD → suitable PKCS#11/FIDO2 device found, but its PIN is locked + * ENOLCK → suitable PKCS#11/FIDO2 device found, but PIN incorrect + * ETOOMANYREFS → suitable PKCS#11 device found, but PIN incorrect, and only few tries left + * EUCLEAN → suitable PKCS#11 device found, but PIN incorrect, and only one try left + * EBUSY → file system is currently active + * ENOEXEC → file system is currently not active + * ENOSPC → not enough disk space for operation + * EKEYREVOKED → user record has not suitable hashed password or pkcs#11 entry, we cannot authenticate + * EADDRINUSE → home image is already used elsewhere (lock taken) + */ + + if (streq(argv[1], "activate")) + r = home_activate(home, &new_home); + else if (streq(argv[1], "deactivate")) + r = home_deactivate(home, false); + else if (streq(argv[1], "deactivate-force")) + r = home_deactivate(home, true); + else if (streq(argv[1], "create")) + r = home_create(home, &new_home); + else if (streq(argv[1], "remove")) + r = home_remove(home); + else if (streq(argv[1], "update")) + r = home_update(home, &new_home); + else if (streq(argv[1], "resize")) /* Resize on user request */ + r = home_resize(home, false, &new_home); + else if (streq(argv[1], "resize-auto")) /* Automatic resize */ + r = home_resize(home, true, &new_home); + else if (streq(argv[1], "passwd")) + r = home_passwd(home, &new_home); + else if (streq(argv[1], "inspect")) + r = home_inspect(home, &new_home); + else if (streq(argv[1], "lock")) + r = home_lock(home); + else if (streq(argv[1], "unlock")) + r = home_unlock(home); + else + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unknown verb '%s'.", argv[1]); + if (IN_SET(r, -ENOKEY, -EREMOTEIO) && !strv_isempty(home->password) ) { /* There were passwords specified but they were incorrect */ + usec_t end, n, d; + + /* Make sure bad password replies always take at least 3s, and if longer multiples of 3s, so + * that it's not clear how long we actually needed for our calculations. */ + n = now(CLOCK_MONOTONIC); + assert(n >= start); + + d = usec_sub_unsigned(n, start); + if (d > BAD_PASSWORD_DELAY_USEC) + end = start + DIV_ROUND_UP(d, BAD_PASSWORD_DELAY_USEC) * BAD_PASSWORD_DELAY_USEC; + else + end = start + BAD_PASSWORD_DELAY_USEC; + + if (n < end) + (void) usleep(usec_sub_unsigned(end, n)); + } + if (r < 0) + return r; + + /* We always pass the new record back, regardless if it changed or not. This allows our caller to + * prepare a fresh record, send to us, and only if it works use it without having to keep a local + * copy. */ + if (new_home) + json_variant_dump(new_home->json, JSON_FORMAT_NEWLINE, stdout, NULL); + + return 0; +} + +DEFINE_MAIN_FUNCTION(run); |