diff options
Diffstat (limited to '')
| -rw-r--r-- | src/home/homework-luks.c | 3087 |
1 files changed, 3087 insertions, 0 deletions
diff --git a/src/home/homework-luks.c b/src/home/homework-luks.c new file mode 100644 index 0000000..b0b2d80 --- /dev/null +++ b/src/home/homework-luks.c @@ -0,0 +1,3087 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <libfdisk.h> +#include <linux/loop.h> +#include <poll.h> +#include <sys/file.h> +#include <sys/ioctl.h> +#include <sys/mount.h> +#include <sys/xattr.h> + +#include "blkid-util.h" +#include "blockdev-util.h" +#include "btrfs-util.h" +#include "chattr-util.h" +#include "dm-util.h" +#include "errno-util.h" +#include "fd-util.h" +#include "fileio.h" +#include "fs-util.h" +#include "fsck-util.h" +#include "home-util.h" +#include "homework-luks.h" +#include "homework-mount.h" +#include "id128-util.h" +#include "io-util.h" +#include "memory-util.h" +#include "missing_magic.h" +#include "mkdir.h" +#include "mkfs-util.h" +#include "mount-util.h" +#include "openssl-util.h" +#include "parse-util.h" +#include "path-util.h" +#include "process-util.h" +#include "random-util.h" +#include "resize-fs.h" +#include "stat-util.h" +#include "strv.h" +#include "tmpfile-util.h" + +/* Round down to the nearest 1K size. Note that Linux generally handles block devices with 512 blocks only, + * but actually doesn't accept uneven numbers in many cases. To avoid any confusion around this we'll + * strictly round disk sizes down to the next 1K boundary.*/ +#define DISK_SIZE_ROUND_DOWN(x) ((x) & ~UINT64_C(1023)) + +int run_mark_dirty(int fd, bool b) { + char x = '1'; + int r, ret; + + /* Sets or removes the 'user.home-dirty' xattr on the specified file. We use this to detect when a + * home directory was not properly unmounted. */ + + assert(fd >= 0); + + r = fd_verify_regular(fd); + if (r < 0) + return r; + + if (b) { + ret = fsetxattr(fd, "user.home-dirty", &x, 1, XATTR_CREATE); + if (ret < 0 && errno != EEXIST) + return log_debug_errno(errno, "Could not mark home directory as dirty: %m"); + + } else { + r = fsync_full(fd); + if (r < 0) + return log_debug_errno(r, "Failed to synchronize image before marking it clean: %m"); + + ret = fremovexattr(fd, "user.home-dirty"); + if (ret < 0 && errno != ENODATA) + return log_debug_errno(errno, "Could not mark home directory as clean: %m"); + } + + r = fsync_full(fd); + if (r < 0) + return log_debug_errno(r, "Failed to synchronize dirty flag to disk: %m"); + + return ret >= 0; +} + +int run_mark_dirty_by_path(const char *path, bool b) { + _cleanup_close_ int fd = -1; + + assert(path); + + fd = open(path, O_RDWR|O_CLOEXEC|O_NOCTTY); + if (fd < 0) + return log_debug_errno(errno, "Failed to open %s to mark dirty or clean: %m", path); + + return run_mark_dirty(fd, b); +} + +static int probe_file_system_by_fd( + int fd, + char **ret_fstype, + sd_id128_t *ret_uuid) { + + _cleanup_(blkid_free_probep) blkid_probe b = NULL; + _cleanup_free_ char *s = NULL; + const char *fstype = NULL, *uuid = NULL; + sd_id128_t id; + int r; + + assert(fd >= 0); + assert(ret_fstype); + assert(ret_uuid); + + b = blkid_new_probe(); + if (!b) + return -ENOMEM; + + errno = 0; + r = blkid_probe_set_device(b, fd, 0, 0); + if (r != 0) + return errno > 0 ? -errno : -ENOMEM; + + (void) blkid_probe_enable_superblocks(b, 1); + (void) blkid_probe_set_superblocks_flags(b, BLKID_SUBLKS_TYPE|BLKID_SUBLKS_UUID); + + errno = 0; + r = blkid_do_safeprobe(b); + if (IN_SET(r, -2, 1)) /* nothing found or ambiguous result */ + return -ENOPKG; + if (r != 0) + return errno > 0 ? -errno : -EIO; + + (void) blkid_probe_lookup_value(b, "TYPE", &fstype, NULL); + if (!fstype) + return -ENOPKG; + + (void) blkid_probe_lookup_value(b, "UUID", &uuid, NULL); + if (!uuid) + return -ENOPKG; + + r = sd_id128_from_string(uuid, &id); + if (r < 0) + return r; + + s = strdup(fstype); + if (!s) + return -ENOMEM; + + *ret_fstype = TAKE_PTR(s); + *ret_uuid = id; + + return 0; +} + +static int probe_file_system_by_path(const char *path, char **ret_fstype, sd_id128_t *ret_uuid) { + _cleanup_close_ int fd = -1; + + fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NONBLOCK); + if (fd < 0) + return -errno; + + return probe_file_system_by_fd(fd, ret_fstype, ret_uuid); +} + +static int block_get_size_by_fd(int fd, uint64_t *ret) { + struct stat st; + + assert(fd >= 0); + assert(ret); + + if (fstat(fd, &st) < 0) + return -errno; + + if (!S_ISBLK(st.st_mode)) + return -ENOTBLK; + + if (ioctl(fd, BLKGETSIZE64, ret) < 0) + return -errno; + + return 0; +} + +static int block_get_size_by_path(const char *path, uint64_t *ret) { + _cleanup_close_ int fd = -1; + + fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NONBLOCK); + if (fd < 0) + return -errno; + + return block_get_size_by_fd(fd, ret); +} + +static int run_fsck(const char *node, const char *fstype) { + int r, exit_status; + pid_t fsck_pid; + + assert(node); + assert(fstype); + + r = fsck_exists(fstype); + if (r < 0) + return log_error_errno(r, "Failed to check if fsck for file system %s exists: %m", fstype); + if (r == 0) { + log_warning("No fsck for file system %s installed, ignoring.", fstype); + return 0; + } + + r = safe_fork("(fsck)", FORK_RESET_SIGNALS|FORK_RLIMIT_NOFILE_SAFE|FORK_DEATHSIG|FORK_LOG|FORK_STDOUT_TO_STDERR, &fsck_pid); + if (r < 0) + return r; + if (r == 0) { + /* Child */ + execl("/sbin/fsck", "/sbin/fsck", "-aTl", node, NULL); + log_error_errno(errno, "Failed to execute fsck: %m"); + _exit(FSCK_OPERATIONAL_ERROR); + } + + exit_status = wait_for_terminate_and_check("fsck", fsck_pid, WAIT_LOG_ABNORMAL); + if (exit_status < 0) + return exit_status; + if ((exit_status & ~FSCK_ERROR_CORRECTED) != 0) { + log_warning("fsck failed with exit status %i.", exit_status); + + if ((exit_status & (FSCK_SYSTEM_SHOULD_REBOOT|FSCK_ERRORS_LEFT_UNCORRECTED)) != 0) + return log_error_errno(SYNTHETIC_ERRNO(EIO), "File system is corrupted, refusing."); + + log_warning("Ignoring fsck error."); + } + + log_info("File system check completed."); + + return 1; +} + +static int luks_try_passwords( + struct crypt_device *cd, + char **passwords, + void *volume_key, + size_t *volume_key_size) { + + char **pp; + int r; + + assert(cd); + + STRV_FOREACH(pp, passwords) { + size_t vks = *volume_key_size; + + r = crypt_volume_key_get( + cd, + CRYPT_ANY_SLOT, + volume_key, + &vks, + *pp, + strlen(*pp)); + if (r >= 0) { + *volume_key_size = vks; + return 0; + } + + log_debug_errno(r, "Password %zu didn't work for unlocking LUKS superblock: %m", (size_t) (pp - passwords)); + } + + return -ENOKEY; +} + +static int luks_setup( + const char *node, + const char *dm_name, + sd_id128_t uuid, + const char *cipher, + const char *cipher_mode, + uint64_t volume_key_size, + char **passwords, + const PasswordCache *cache, + bool discard, + struct crypt_device **ret, + sd_id128_t *ret_found_uuid, + void **ret_volume_key, + size_t *ret_volume_key_size) { + + _cleanup_(crypt_freep) struct crypt_device *cd = NULL; + _cleanup_(erase_and_freep) void *vk = NULL; + sd_id128_t p; + size_t vks; + char **list; + int r; + + assert(node); + assert(dm_name); + assert(ret); + + r = crypt_init(&cd, node); + if (r < 0) + return log_error_errno(r, "Failed to allocate libcryptsetup context: %m"); + + cryptsetup_enable_logging(cd); + + r = crypt_load(cd, CRYPT_LUKS2, NULL); + if (r < 0) + return log_error_errno(r, "Failed to load LUKS superblock: %m"); + + r = crypt_get_volume_key_size(cd); + if (r <= 0) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to determine LUKS volume key size"); + vks = (size_t) r; + + if (!sd_id128_is_null(uuid) || ret_found_uuid) { + const char *s; + + s = crypt_get_uuid(cd); + if (!s) + return log_error_errno(SYNTHETIC_ERRNO(EMEDIUMTYPE), "LUKS superblock has no UUID."); + + r = sd_id128_from_string(s, &p); + if (r < 0) + return log_error_errno(SYNTHETIC_ERRNO(EMEDIUMTYPE), "LUKS superblock has invalid UUID."); + + /* Check that the UUID matches, if specified */ + if (!sd_id128_is_null(uuid) && + !sd_id128_equal(uuid, p)) + return log_error_errno(SYNTHETIC_ERRNO(EMEDIUMTYPE), "LUKS superblock has wrong UUID."); + } + + if (cipher && !streq_ptr(cipher, crypt_get_cipher(cd))) + return log_error_errno(SYNTHETIC_ERRNO(EMEDIUMTYPE), "LUKS superblock declares wrong cipher."); + + if (cipher_mode && !streq_ptr(cipher_mode, crypt_get_cipher_mode(cd))) + return log_error_errno(SYNTHETIC_ERRNO(EMEDIUMTYPE), "LUKS superblock declares wrong cipher mode."); + + if (volume_key_size != UINT64_MAX && vks != volume_key_size) + return log_error_errno(SYNTHETIC_ERRNO(EMEDIUMTYPE), "LUKS superblock declares wrong volume key size."); + + vk = malloc(vks); + if (!vk) + return log_oom(); + + r = -ENOKEY; + FOREACH_POINTER(list, cache->pkcs11_passwords, cache->fido2_passwords, passwords) { + r = luks_try_passwords(cd, list, vk, &vks); + if (r != -ENOKEY) + break; + } + if (r == -ENOKEY) + return log_error_errno(r, "No valid password for LUKS superblock."); + if (r < 0) + return log_error_errno(r, "Failed to unlocks LUKS superblock: %m"); + + r = crypt_activate_by_volume_key( + cd, + dm_name, + vk, vks, + discard ? CRYPT_ACTIVATE_ALLOW_DISCARDS : 0); + if (r < 0) + return log_error_errno(r, "Failed to unlock LUKS superblock: %m"); + + log_info("Setting up LUKS device /dev/mapper/%s completed.", dm_name); + + *ret = TAKE_PTR(cd); + + if (ret_found_uuid) /* Return the UUID actually found if the caller wants to know */ + *ret_found_uuid = p; + if (ret_volume_key) + *ret_volume_key = TAKE_PTR(vk); + if (ret_volume_key_size) + *ret_volume_key_size = vks; + + return 0; +} + +static int luks_open( + const char *dm_name, + char **passwords, + PasswordCache *cache, + struct crypt_device **ret, + sd_id128_t *ret_found_uuid, + void **ret_volume_key, + size_t *ret_volume_key_size) { + + _cleanup_(crypt_freep) struct crypt_device *cd = NULL; + _cleanup_(erase_and_freep) void *vk = NULL; + sd_id128_t p; + char **list; + size_t vks; + int r; + + assert(dm_name); + assert(ret); + + /* Opens a LUKS device that is already set up. Re-validates the password while doing so (which also + * provides us with the volume key, which we want). */ + + r = crypt_init_by_name(&cd, dm_name); + if (r < 0) + return log_error_errno(r, "Failed to initialize cryptsetup context for %s: %m", dm_name); + + cryptsetup_enable_logging(cd); + + r = crypt_load(cd, CRYPT_LUKS2, NULL); + if (r < 0) + return log_error_errno(r, "Failed to load LUKS superblock: %m"); + + r = crypt_get_volume_key_size(cd); + if (r <= 0) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to determine LUKS volume key size"); + vks = (size_t) r; + + if (ret_found_uuid) { + const char *s; + + s = crypt_get_uuid(cd); + if (!s) + return log_error_errno(SYNTHETIC_ERRNO(EMEDIUMTYPE), "LUKS superblock has no UUID."); + + r = sd_id128_from_string(s, &p); + if (r < 0) + return log_error_errno(SYNTHETIC_ERRNO(EMEDIUMTYPE), "LUKS superblock has invalid UUID."); + } + + vk = malloc(vks); + if (!vk) + return log_oom(); + + r = -ENOKEY; + FOREACH_POINTER(list, cache->pkcs11_passwords, cache->fido2_passwords, passwords) { + r = luks_try_passwords(cd, list, vk, &vks); + if (r != -ENOKEY) + break; + } + if (r == -ENOKEY) + return log_error_errno(r, "No valid password for LUKS superblock."); + if (r < 0) + return log_error_errno(r, "Failed to unlocks LUKS superblock: %m"); + + log_info("Discovered used LUKS device /dev/mapper/%s, and validated password.", dm_name); + + /* This is needed so that crypt_resize() can operate correctly for pre-existing LUKS devices. We need + * to tell libcryptsetup the volume key explicitly, so that it is in the kernel keyring. */ + r = crypt_activate_by_volume_key(cd, NULL, vk, vks, CRYPT_ACTIVATE_KEYRING_KEY); + if (r < 0) + return log_error_errno(r, "Failed to upload volume key again: %m"); + + log_info("Successfully re-activated LUKS device."); + + *ret = TAKE_PTR(cd); + + if (ret_found_uuid) + *ret_found_uuid = p; + if (ret_volume_key) + *ret_volume_key = TAKE_PTR(vk); + if (ret_volume_key_size) + *ret_volume_key_size = vks; + + return 0; +} + +static int fs_validate( + const char *dm_node, + sd_id128_t uuid, + char **ret_fstype, + sd_id128_t *ret_found_uuid) { + + _cleanup_free_ char *fstype = NULL; + sd_id128_t u; + int r; + + assert(dm_node); + assert(ret_fstype); + + r = probe_file_system_by_path(dm_node, &fstype, &u); + if (r < 0) + return log_error_errno(r, "Failed to probe file system: %m"); + + /* Limit the set of supported file systems a bit, as protection against little tested kernel file + * systems. Also, we only support the resize ioctls for these file systems. */ + if (!supported_fstype(fstype)) + return log_error_errno(SYNTHETIC_ERRNO(EPROTONOSUPPORT), "Image contains unsupported file system: %s", strna(fstype)); + + if (!sd_id128_is_null(uuid) && + !sd_id128_equal(uuid, u)) + return log_error_errno(SYNTHETIC_ERRNO(EMEDIUMTYPE), "File system has wrong UUID."); + + log_info("Probing file system completed (found %s).", fstype); + + *ret_fstype = TAKE_PTR(fstype); + + if (ret_found_uuid) /* Return the UUID actually found if the caller wants to know */ + *ret_found_uuid = u; + + return 0; +} + +static int make_dm_names(const char *user_name, char **ret_dm_name, char **ret_dm_node) { + _cleanup_free_ char *name = NULL, *node = NULL; + + assert(user_name); + assert(ret_dm_name); + assert(ret_dm_node); + + name = strjoin("home-", user_name); + if (!name) + return log_oom(); + + node = path_join("/dev/mapper/", name); + if (!node) + return log_oom(); + + *ret_dm_name = TAKE_PTR(name); + *ret_dm_node = TAKE_PTR(node); + return 0; +} + +static int luks_validate( + int fd, + const char *label, + sd_id128_t partition_uuid, + sd_id128_t *ret_partition_uuid, + uint64_t *ret_offset, + uint64_t *ret_size) { + + _cleanup_(blkid_free_probep) blkid_probe b = NULL; + sd_id128_t found_partition_uuid = SD_ID128_NULL; + const char *fstype = NULL, *pttype = NULL; + blkid_loff_t offset = 0, size = 0; + blkid_partlist pl; + bool found = false; + int r, i, n; + + assert(fd >= 0); + assert(label); + assert(ret_offset); + assert(ret_size); + + b = blkid_new_probe(); + if (!b) + return -ENOMEM; + + errno = 0; + r = blkid_probe_set_device(b, fd, 0, 0); + if (r != 0) + return errno > 0 ? -errno : -ENOMEM; + + (void) blkid_probe_enable_superblocks(b, 1); + (void) blkid_probe_set_superblocks_flags(b, BLKID_SUBLKS_TYPE); + (void) blkid_probe_enable_partitions(b, 1); + (void) blkid_probe_set_partitions_flags(b, BLKID_PARTS_ENTRY_DETAILS); + + errno = 0; + r = blkid_do_safeprobe(b); + if (IN_SET(r, -2, 1)) /* nothing found or ambiguous result */ + return -ENOPKG; + if (r != 0) + return errno > 0 ? -errno : -EIO; + + (void) blkid_probe_lookup_value(b, "TYPE", &fstype, NULL); + if (streq_ptr(fstype, "crypto_LUKS")) { + /* Directly a LUKS image */ + *ret_offset = 0; + *ret_size = UINT64_MAX; /* full disk */ + *ret_partition_uuid = SD_ID128_NULL; + return 0; + } else if (fstype) + return -ENOPKG; + + (void) blkid_probe_lookup_value(b, "PTTYPE", &pttype, NULL); + if (!streq_ptr(pttype, "gpt")) + return -ENOPKG; + + errno = 0; + pl = blkid_probe_get_partitions(b); + if (!pl) + return errno > 0 ? -errno : -ENOMEM; + + errno = 0; + n = blkid_partlist_numof_partitions(pl); + if (n < 0) + return errno > 0 ? -errno : -EIO; + + for (i = 0; i < n; i++) { + blkid_partition pp; + sd_id128_t id; + const char *sid; + + errno = 0; + pp = blkid_partlist_get_partition(pl, i); + if (!pp) + return errno > 0 ? -errno : -EIO; + + if (!streq_ptr(blkid_partition_get_type_string(pp), "773f91ef-66d4-49b5-bd83-d683bf40ad16")) + continue; + + if (!streq_ptr(blkid_partition_get_name(pp), label)) + continue; + + sid = blkid_partition_get_uuid(pp); + if (sid) { + r = sd_id128_from_string(sid, &id); + if (r < 0) + log_debug_errno(r, "Couldn't parse partition UUID %s, weird: %m", sid); + + if (!sd_id128_is_null(partition_uuid) && !sd_id128_equal(id, partition_uuid)) + continue; + } + + if (found) + return -ENOPKG; + + offset = blkid_partition_get_start(pp); + size = blkid_partition_get_size(pp); + found_partition_uuid = id; + + found = true; + } + + if (!found) + return -ENOPKG; + + if (offset < 0) + return -EINVAL; + if ((uint64_t) offset > UINT64_MAX / 512U) + return -EINVAL; + if (size <= 0) + return -EINVAL; + if ((uint64_t) size > UINT64_MAX / 512U) + return -EINVAL; + + *ret_offset = offset * 512U; + *ret_size = size * 512U; + *ret_partition_uuid = found_partition_uuid; + + return 0; +} + +static int crypt_device_to_evp_cipher(struct crypt_device *cd, const EVP_CIPHER **ret) { + _cleanup_free_ char *cipher_name = NULL; + const char *cipher, *cipher_mode, *e; + size_t key_size, key_bits; + const EVP_CIPHER *cc; + int r; + + assert(cd); + + /* Let's find the right OpenSSL EVP_CIPHER object that matches the encryption settings of the LUKS + * device */ + + cipher = crypt_get_cipher(cd); + if (!cipher) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot get cipher from LUKS device."); + + cipher_mode = crypt_get_cipher_mode(cd); + if (!cipher_mode) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot get cipher mode from LUKS device."); + + e = strchr(cipher_mode, '-'); + if (e) + cipher_mode = strndupa(cipher_mode, e - cipher_mode); + + r = crypt_get_volume_key_size(cd); + if (r <= 0) + return log_error_errno(r < 0 ? r : SYNTHETIC_ERRNO(EINVAL), "Cannot get volume key size from LUKS device."); + + key_size = r; + key_bits = key_size * 8; + if (streq(cipher_mode, "xts")) + key_bits /= 2; + + if (asprintf(&cipher_name, "%s-%zu-%s", cipher, key_bits, cipher_mode) < 0) + return log_oom(); + + cc = EVP_get_cipherbyname(cipher_name); + if (!cc) + return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Selected cipher mode '%s' not supported, can't encrypt JSON record.", cipher_name); + + /* Verify that our key length calculations match what OpenSSL thinks */ + r = EVP_CIPHER_key_length(cc); + if (r < 0 || (uint64_t) r != key_size) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Key size of selected cipher doesn't meet our expectations."); + + *ret = cc; + return 0; +} + +static int luks_validate_home_record( + struct crypt_device *cd, + UserRecord *h, + const void *volume_key, + PasswordCache *cache, + UserRecord **ret_luks_home_record) { + + int r, token; + + assert(cd); + assert(h); + + for (token = 0;; token++) { + _cleanup_(json_variant_unrefp) JsonVariant *v = NULL, *rr = NULL; + _cleanup_(EVP_CIPHER_CTX_freep) EVP_CIPHER_CTX *context = NULL; + _cleanup_(user_record_unrefp) UserRecord *lhr = NULL; + _cleanup_free_ void *encrypted = NULL, *iv = NULL; + size_t decrypted_size, encrypted_size, iv_size; + int decrypted_size_out1, decrypted_size_out2; + _cleanup_free_ char *decrypted = NULL; + const char *text, *type; + crypt_token_info state; + JsonVariant *jr, *jiv; + unsigned line, column; + const EVP_CIPHER *cc; + + state = crypt_token_status(cd, token, &type); + if (state == CRYPT_TOKEN_INACTIVE) /* First unconfigured token, give up */ + break; + if (IN_SET(state, CRYPT_TOKEN_INTERNAL, CRYPT_TOKEN_INTERNAL_UNKNOWN, CRYPT_TOKEN_EXTERNAL)) + continue; + if (state != CRYPT_TOKEN_EXTERNAL_UNKNOWN) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unexpected token state of token %i: %i", token, (int) state); + + if (!streq(type, "systemd-homed")) + continue; + + r = crypt_token_json_get(cd, token, &text); + if (r < 0) + return log_error_errno(r, "Failed to read LUKS token %i: %m", token); + + r = json_parse(text, JSON_PARSE_SENSITIVE, &v, &line, &column); + if (r < 0) + return log_error_errno(r, "Failed to parse LUKS token JSON data %u:%u: %m", line, column); + + jr = json_variant_by_key(v, "record"); + if (!jr) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "LUKS token lacks 'record' field."); + jiv = json_variant_by_key(v, "iv"); + if (!jiv) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "LUKS token lacks 'iv' field."); + + r = json_variant_unbase64(jr, &encrypted, &encrypted_size); + if (r < 0) + return log_error_errno(r, "Failed to base64 decode record: %m"); + + r = json_variant_unbase64(jiv, &iv, &iv_size); + if (r < 0) + return log_error_errno(r, "Failed to base64 decode IV: %m"); + + r = crypt_device_to_evp_cipher(cd, &cc); + if (r < 0) + return r; + if (iv_size > INT_MAX || EVP_CIPHER_iv_length(cc) != (int) iv_size) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "IV size doesn't match."); + + context = EVP_CIPHER_CTX_new(); + if (!context) + return log_oom(); + + if (EVP_DecryptInit_ex(context, cc, NULL, volume_key, iv) != 1) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to initialize decryption context."); + + decrypted_size = encrypted_size + EVP_CIPHER_key_length(cc) * 2; + decrypted = new(char, decrypted_size); + if (!decrypted) + return log_oom(); + + if (EVP_DecryptUpdate(context, (uint8_t*) decrypted, &decrypted_size_out1, encrypted, encrypted_size) != 1) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to decrypt JSON record."); + + assert((size_t) decrypted_size_out1 <= decrypted_size); + + if (EVP_DecryptFinal_ex(context, (uint8_t*) decrypted + decrypted_size_out1, &decrypted_size_out2) != 1) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to finish decryption of JSON record."); + + assert((size_t) decrypted_size_out1 + (size_t) decrypted_size_out2 < decrypted_size); + decrypted_size = (size_t) decrypted_size_out1 + (size_t) decrypted_size_out2; + + if (memchr(decrypted, 0, decrypted_size)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Inner NUL byte in JSON record, refusing."); + + decrypted[decrypted_size] = 0; + + r = json_parse(decrypted, JSON_PARSE_SENSITIVE, &rr, NULL, NULL); + if (r < 0) + return log_error_errno(r, "Failed to parse decrypted JSON record, refusing."); + + lhr = user_record_new(); + if (!lhr) + return log_oom(); + + r = user_record_load(lhr, rr, USER_RECORD_LOAD_EMBEDDED); + if (r < 0) + return log_error_errno(r, "Failed to parse user record: %m"); + + if (!user_record_compatible(h, lhr)) + return log_error_errno(SYNTHETIC_ERRNO(EREMCHG), "LUKS home record not compatible with host record, refusing."); + + r = user_record_authenticate(lhr, h, cache, /* strict_verify= */ true); + if (r < 0) + return r; + assert(r > 0); /* Insist that a password was verified */ + + *ret_luks_home_record = TAKE_PTR(lhr); + return 0; + } + + return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Couldn't find home record in LUKS2 header, refusing."); +} + +static int format_luks_token_text( + struct crypt_device *cd, + UserRecord *hr, + const void *volume_key, + char **ret) { + + int r, encrypted_size_out1 = 0, encrypted_size_out2 = 0, iv_size, key_size; + _cleanup_(EVP_CIPHER_CTX_freep) EVP_CIPHER_CTX *context = NULL; + _cleanup_(json_variant_unrefp) JsonVariant *v = NULL; + _cleanup_free_ void *iv = NULL, *encrypted = NULL; + size_t text_length, encrypted_size; + _cleanup_free_ char *text = NULL; + const EVP_CIPHER *cc; + + assert(cd); + assert(hr); + assert(volume_key); + assert(ret); + + r = crypt_device_to_evp_cipher(cd, &cc); + if (r < 0) + return r; + + key_size = EVP_CIPHER_key_length(cc); + iv_size = EVP_CIPHER_iv_length(cc); + + if (iv_size > 0) { + iv = malloc(iv_size); + if (!iv) + return log_oom(); + + r = genuine_random_bytes(iv, iv_size, RANDOM_BLOCK); + if (r < 0) + return log_error_errno(r, "Failed to generate IV: %m"); + } + + context = EVP_CIPHER_CTX_new(); + if (!context) + return log_oom(); + + if (EVP_EncryptInit_ex(context, cc, NULL, volume_key, iv) != 1) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to initialize encryption context."); + + r = json_variant_format(hr->json, 0, &text); + if (r < 0) + return log_error_errno(r, "Failed to format user record for LUKS: %m"); + + text_length = strlen(text); + encrypted_size = text_length + 2*key_size - 1; + + encrypted = malloc(encrypted_size); + if (!encrypted) + return log_oom(); + + if (EVP_EncryptUpdate(context, encrypted, &encrypted_size_out1, (uint8_t*) text, text_length) != 1) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to encrypt JSON record."); + + assert((size_t) encrypted_size_out1 <= encrypted_size); + + if (EVP_EncryptFinal_ex(context, (uint8_t*) encrypted + encrypted_size_out1, &encrypted_size_out2) != 1) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to finish encryption of JSON record. "); + + assert((size_t) encrypted_size_out1 + (size_t) encrypted_size_out2 <= encrypted_size); + + r = json_build(&v, + JSON_BUILD_OBJECT( + JSON_BUILD_PAIR("type", JSON_BUILD_STRING("systemd-homed")), + JSON_BUILD_PAIR("keyslots", JSON_BUILD_EMPTY_ARRAY), + JSON_BUILD_PAIR("record", JSON_BUILD_BASE64(encrypted, encrypted_size_out1 + encrypted_size_out2)), + JSON_BUILD_PAIR("iv", JSON_BUILD_BASE64(iv, iv_size)))); + if (r < 0) + return log_error_errno(r, "Failed to prepare LUKS JSON token object: %m"); + + r = json_variant_format(v, 0, ret); + if (r < 0) + return log_error_errno(r, "Failed to format encrypted user record for LUKS: %m"); + + return 0; +} + +int home_store_header_identity_luks( + UserRecord *h, + HomeSetup *setup, + UserRecord *old_home) { + + _cleanup_(user_record_unrefp) UserRecord *header_home = NULL; + _cleanup_free_ char *text = NULL; + int token = 0, r; + + assert(h); + + if (!setup->crypt_device) + return 0; + + assert(setup->volume_key); + + /* Let's store the user's identity record in the LUKS2 "token" header data fields, in an encrypted + * fashion. Why that? If we'd rely on the record being embedded in the payload file system itself we + * would have to mount the file system before we can validate the JSON record, its signatures and + * whether it matches what we are looking for. However, kernel file system implementations are + * generally not ready to be used on untrusted media. Hence let's store the record independently of + * the file system, so that we can validate it first, and only then mount the file system. To keep + * things simple we use the same encryption settings for this record as for the file system itself. */ + + r = user_record_clone(h, USER_RECORD_EXTRACT_EMBEDDED, &header_home); + if (r < 0) + return log_error_errno(r, "Failed to determine new header record: %m"); + + if (old_home && user_record_equal(old_home, header_home)) { + log_debug("Not updating header home record."); + return 0; + } + + r = format_luks_token_text(setup->crypt_device, header_home, setup->volume_key, &text); + if (r < 0) + return r; + + for (;; token++) { + crypt_token_info state; + const char *type; + + state = crypt_token_status(setup->crypt_device, token, &type); + if (state == CRYPT_TOKEN_INACTIVE) /* First unconfigured token, we are done */ + break; + if (IN_SET(state, CRYPT_TOKEN_INTERNAL, CRYPT_TOKEN_INTERNAL_UNKNOWN, CRYPT_TOKEN_EXTERNAL)) + continue; /* Not ours */ + if (state != CRYPT_TOKEN_EXTERNAL_UNKNOWN) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unexpected token state of token %i: %i", token, (int) state); + + if (!streq(type, "systemd-homed")) + continue; + + r = crypt_token_json_set(setup->crypt_device, token, text); + if (r < 0) + return log_error_errno(r, "Failed to set JSON token for slot %i: %m", token); + + /* Now, let's free the text so that for all further matching tokens we all crypt_json_token_set() + * with a NULL text in order to invalidate the tokens. */ + text = mfree(text); + token++; + } + + if (text) + return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Didn't find any record token to update."); + + log_info("Wrote LUKS header user record."); + + return 1; +} + +int run_fitrim(int root_fd) { + char buf[FORMAT_BYTES_MAX]; + struct fstrim_range range = { + .len = UINT64_MAX, + }; + + /* If discarding is on, discard everything right after mounting, so that the discard setting takes + * effect on activation. (Also, optionally, trim on logout) */ + + assert(root_fd >= 0); + + if (ioctl(root_fd, FITRIM, &range) < 0) { + if (ERRNO_IS_NOT_SUPPORTED(errno) || errno == EBADF) { + log_debug_errno(errno, "File system does not support FITRIM, not trimming."); + return 0; + } + + return log_warning_errno(errno, "Failed to invoke FITRIM, ignoring: %m"); + } + + log_info("Discarded unused %s.", + format_bytes(buf, sizeof(buf), range.len)); + return 1; +} + +int run_fitrim_by_path(const char *root_path) { + _cleanup_close_ int root_fd = -1; + + root_fd = open(root_path, O_RDONLY|O_DIRECTORY|O_CLOEXEC); + if (root_fd < 0) + return log_error_errno(errno, "Failed to open file system '%s' for trimming: %m", root_path); + + return run_fitrim(root_fd); +} + +int run_fallocate(int backing_fd, const struct stat *st) { + char buf[FORMAT_BYTES_MAX]; + struct stat stbuf; + + assert(backing_fd >= 0); + + /* If discarding is off, let's allocate the whole image before mounting, so that the setting takes + * effect on activation */ + + if (!st) { + if (fstat(backing_fd, &stbuf) < 0) + return log_error_errno(errno, "Failed to fstat(): %m"); + + st = &stbuf; + } + + if (!S_ISREG(st->st_mode)) + return 0; + + if (st->st_blocks >= DIV_ROUND_UP(st->st_size, 512)) { + log_info("Backing file is fully allocated already."); + return 0; + } + + if (fallocate(backing_fd, FALLOC_FL_KEEP_SIZE, 0, st->st_size) < 0) { + + if (ERRNO_IS_NOT_SUPPORTED(errno)) { + log_debug_errno(errno, "fallocate() not supported on file system, ignoring."); + return 0; + } + + if (ERRNO_IS_DISK_SPACE(errno)) { + log_debug_errno(errno, "Not enough disk space to fully allocate home."); + return -ENOSPC; /* make recognizable */ + } + + return log_error_errno(errno, "Failed to allocate backing file blocks: %m"); + } + + log_info("Allocated additional %s.", + format_bytes(buf, sizeof(buf), (DIV_ROUND_UP(st->st_size, 512) - st->st_blocks) * 512)); + return 1; +} + +int run_fallocate_by_path(const char *backing_path) { + _cleanup_close_ int backing_fd = -1; + + backing_fd = open(backing_path, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK); + if (backing_fd < 0) + return log_error_errno(errno, "Failed to open '%s' for fallocate(): %m", backing_path); + + return run_fallocate(backing_fd, NULL); +} + +int home_prepare_luks( + UserRecord *h, + bool already_activated, + const char *force_image_path, + PasswordCache *cache, + HomeSetup *setup, + UserRecord **ret_luks_home) { + + sd_id128_t found_partition_uuid, found_luks_uuid, found_fs_uuid; + _cleanup_(user_record_unrefp) UserRecord *luks_home = NULL; + _cleanup_(loop_device_unrefp) LoopDevice *loop = NULL; + _cleanup_(crypt_freep) struct crypt_device *cd = NULL; + _cleanup_(erase_and_freep) void *volume_key = NULL; + _cleanup_close_ int root_fd = -1, image_fd = -1; + bool dm_activated = false, mounted = false; + size_t volume_key_size = 0; + bool marked_dirty = false; + uint64_t offset, size; + int r; + + assert(h); + assert(setup); + assert(setup->dm_name); + assert(setup->dm_node); + + assert(user_record_storage(h) == USER_LUKS); + + if (already_activated) { + struct loop_info64 info; + const char *n; + + r = luks_open(setup->dm_name, + h->password, + cache, + &cd, + &found_luks_uuid, + &volume_key, + &volume_key_size); + if (r < 0) + return r; + + r = luks_validate_home_record(cd, h, volume_key, cache, &luks_home); + if (r < 0) + return r; + + n = crypt_get_device_name(cd); + if (!n) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to determine backing device for DM %s.", setup->dm_name); + + r = loop_device_open(n, O_RDWR, &loop); + if (r < 0) + return log_error_errno(r, "Failed to open loopback device %s: %m", n); + + if (ioctl(loop->fd, LOOP_GET_STATUS64, &info) < 0) { + _cleanup_free_ char *sysfs = NULL; + struct stat st; + + if (!IN_SET(errno, ENOTTY, EINVAL)) + return log_error_errno(errno, "Failed to get block device metrics of %s: %m", n); + + if (ioctl(loop->fd, BLKGETSIZE64, &size) < 0) + return log_error_errno(r, "Failed to read block device size of %s: %m", n); + + if (fstat(loop->fd, &st) < 0) + return log_error_errno(r, "Failed to stat block device %s: %m", n); + assert(S_ISBLK(st.st_mode)); + + if (asprintf(&sysfs, "/sys/dev/block/%u:%u/partition", major(st.st_rdev), minor(st.st_rdev)) < 0) + return log_oom(); + + if (access(sysfs, F_OK) < 0) { + if (errno != ENOENT) + return log_error_errno(errno, "Failed to determine whether %s exists: %m", sysfs); + + offset = 0; + } else { + _cleanup_free_ char *buffer = NULL; + + if (asprintf(&sysfs, "/sys/dev/block/%u:%u/start", major(st.st_rdev), minor(st.st_rdev)) < 0) + return log_oom(); + + r = read_one_line_file(sysfs, &buffer); + if (r < 0) + return log_error_errno(r, "Failed to read partition start offset: %m"); + + r = safe_atou64(buffer, &offset); + if (r < 0) + return log_error_errno(r, "Failed to parse partition start offset: %m"); + + if (offset > UINT64_MAX / 512U) + return log_error_errno(SYNTHETIC_ERRNO(E2BIG), "Offset too large for 64 byte range, refusing."); + + offset *= 512U; + } + } else { + offset = info.lo_offset; + size = info.lo_sizelimit; + } + + found_partition_uuid = found_fs_uuid = SD_ID128_NULL; + + log_info("Discovered used loopback device %s.", loop->node); + + root_fd = open(user_record_home_directory(h), O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW); + if (root_fd < 0) { + r = log_error_errno(r, "Failed to open home directory: %m"); + goto fail; + } + } else { + _cleanup_free_ char *fstype = NULL, *subdir = NULL; + const char *ip; + struct stat st; + + ip = force_image_path ?: user_record_image_path(h); + + subdir = path_join("/run/systemd/user-home-mount/", user_record_user_name_and_realm(h)); + if (!subdir) + return log_oom(); + + image_fd = open(ip, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK); + if (image_fd < 0) + return log_error_errno(errno, "Failed to open image file %s: %m", ip); + + if (fstat(image_fd, &st) < 0) + return log_error_errno(errno, "Failed to fstat() image file: %m"); + if (!S_ISREG(st.st_mode) && !S_ISBLK(st.st_mode)) + return log_error_errno( + S_ISDIR(st.st_mode) ? SYNTHETIC_ERRNO(EISDIR) : SYNTHETIC_ERRNO(EBADFD), + "Image file %s is not a regular file or block device: %m", ip); + + r = luks_validate(image_fd, user_record_user_name_and_realm(h), h->partition_uuid, &found_partition_uuid, &offset, &size); + if (r < 0) + return log_error_errno(r, "Failed to validate disk label: %m"); + + /* Everything before this point left the image untouched. We are now starting to make + * changes, hence mark the image dirty */ + marked_dirty = run_mark_dirty(image_fd, true) > 0; + + if (!user_record_luks_discard(h)) { + r = run_fallocate(image_fd, &st); + if (r < 0) + return r; + } + + r = loop_device_make(image_fd, O_RDWR, offset, size, 0, &loop); + if (r == -ENOENT) { + log_error_errno(r, "Loopback block device support is not available on this system."); + return -ENOLINK; /* make recognizable */ + } + if (r < 0) + return log_error_errno(r, "Failed to allocate loopback context: %m"); + + log_info("Setting up loopback device %s completed.", loop->node ?: ip); + + r = luks_setup(loop->node ?: ip, + setup->dm_name, + h->luks_uuid, + h->luks_cipher, + h->luks_cipher_mode, + h->luks_volume_key_size, + h->password, + cache, + user_record_luks_discard(h) || user_record_luks_offline_discard(h), + &cd, + &found_luks_uuid, + &volume_key, + &volume_key_size); + if (r < 0) + return r; + + dm_activated = true; + + r = luks_validate_home_record(cd, h, volume_key, cache, &luks_home); + if (r < 0) + goto fail; + + r = fs_validate(setup->dm_node, h->file_system_uuid, &fstype, &found_fs_uuid); + if (r < 0) + goto fail; + + r = run_fsck(setup->dm_node, fstype); + if (r < 0) + goto fail; + + r = home_unshare_and_mount(setup->dm_node, fstype, user_record_luks_discard(h), user_record_mount_flags(h)); + if (r < 0) + goto fail; + + mounted = true; + + root_fd = open(subdir, O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW); + if (root_fd < 0) { + r = log_error_errno(r, "Failed to open home directory: %m"); + goto fail; + } + + if (user_record_luks_discard(h)) + (void) run_fitrim(root_fd); + + setup->image_fd = TAKE_FD(image_fd); + setup->do_offline_fallocate = !(setup->do_offline_fitrim = user_record_luks_offline_discard(h)); + setup->do_mark_clean = marked_dirty; + } + + setup->loop = TAKE_PTR(loop); + setup->crypt_device = TAKE_PTR(cd); + setup->root_fd = TAKE_FD(root_fd); + setup->found_partition_uuid = found_partition_uuid; + setup->found_luks_uuid = found_luks_uuid; + setup->found_fs_uuid = found_fs_uuid; + setup->partition_offset = offset; + setup->partition_size = size; + setup->volume_key = TAKE_PTR(volume_key); + setup->volume_key_size = volume_key_size; + + setup->undo_mount = mounted; + setup->undo_dm = dm_activated; + + if (ret_luks_home) + *ret_luks_home = TAKE_PTR(luks_home); + + return 0; + +fail: + if (mounted) + (void) umount_verbose(LOG_ERR, "/run/systemd/user-home-mount", UMOUNT_NOFOLLOW); + + if (dm_activated) + (void) crypt_deactivate(cd, setup->dm_name); + + if (image_fd >= 0 && marked_dirty) + (void) run_mark_dirty(image_fd, false); + + return r; +} + +static void print_size_summary(uint64_t host_size, uint64_t encrypted_size, struct statfs *sfs) { + char buffer1[FORMAT_BYTES_MAX], buffer2[FORMAT_BYTES_MAX], buffer3[FORMAT_BYTES_MAX], buffer4[FORMAT_BYTES_MAX]; + + assert(sfs); + + log_info("Image size is %s, file system size is %s, file system payload size is %s, file system free is %s.", + format_bytes(buffer1, sizeof(buffer1), host_size), + format_bytes(buffer2, sizeof(buffer2), encrypted_size), + format_bytes(buffer3, sizeof(buffer3), (uint64_t) sfs->f_blocks * (uint64_t) sfs->f_frsize), + format_bytes(buffer4, sizeof(buffer4), (uint64_t) sfs->f_bfree * (uint64_t) sfs->f_frsize)); +} + +int home_activate_luks( + UserRecord *h, + PasswordCache *cache, + UserRecord **ret_home) { + + _cleanup_(user_record_unrefp) UserRecord *new_home = NULL, *luks_home_record = NULL; + _cleanup_(home_setup_undo) HomeSetup setup = HOME_SETUP_INIT; + uint64_t host_size, encrypted_size; + const char *hdo, *hd; + struct statfs sfs; + int r; + + assert(h); + assert(user_record_storage(h) == USER_LUKS); + assert(ret_home); + + assert_se(hdo = user_record_home_directory(h)); + hd = strdupa(hdo); /* copy the string out, since it might change later in the home record object */ + + r = make_dm_names(h->user_name, &setup.dm_name, &setup.dm_node); + if (r < 0) + return r; + + r = access(setup.dm_node, F_OK); + if (r < 0) { + if (errno != ENOENT) + return log_error_errno(errno, "Failed to determine whether %s exists: %m", setup.dm_node); + } else + return log_error_errno(SYNTHETIC_ERRNO(EEXIST), "Device mapper device %s already exists, refusing.", setup.dm_node); + + r = home_prepare_luks( + h, + false, + NULL, + cache, + &setup, + &luks_home_record); + if (r < 0) + return r; + + r = block_get_size_by_fd(setup.loop->fd, &host_size); + if (r < 0) + return log_error_errno(r, "Failed to get loopback block device size: %m"); + + r = block_get_size_by_path(setup.dm_node, &encrypted_size); + if (r < 0) + return log_error_errno(r, "Failed to get LUKS block device size: %m"); + + r = home_refresh( + h, + &setup, + luks_home_record, + cache, + &sfs, + &new_home); + if (r < 0) + return r; + + r = home_extend_embedded_identity(new_home, h, &setup); + if (r < 0) + return r; + + setup.root_fd = safe_close(setup.root_fd); + + r = home_move_mount(user_record_user_name_and_realm(h), hd); + if (r < 0) + return r; + + setup.undo_mount = false; + setup.do_offline_fitrim = false; + + loop_device_relinquish(setup.loop); + + r = crypt_deactivate_by_name(NULL, setup.dm_name, CRYPT_DEACTIVATE_DEFERRED); + if (r < 0) + log_warning_errno(r, "Failed to relinquish DM device, ignoring: %m"); + + setup.undo_dm = false; + setup.do_offline_fallocate = false; + setup.do_mark_clean = false; + + log_info("Everything completed."); + + print_size_summary(host_size, encrypted_size, &sfs); + + *ret_home = TAKE_PTR(new_home); + return 1; +} + +int home_deactivate_luks(UserRecord *h) { + _cleanup_(crypt_freep) struct crypt_device *cd = NULL; + _cleanup_free_ char *dm_name = NULL, *dm_node = NULL; + bool we_detached; + int r; + + /* Note that the DM device and loopback device are set to auto-detach, hence strictly speaking we + * don't have to explicitly have to detach them. However, we do that nonetheless (in case of the DM + * device), to avoid races: by explicitly detaching them we know when the detaching is complete. We + * don't bother about the loopback device because unlike the DM device it doesn't have a fixed + * name. */ + + r = make_dm_names(h->user_name, &dm_name, &dm_node); + if (r < 0) + return r; + + r = crypt_init_by_name(&cd, dm_name); + if (IN_SET(r, -ENODEV, -EINVAL, -ENOENT)) { + log_debug_errno(r, "LUKS device %s has already been detached.", dm_name); + we_detached = false; + } else if (r < 0) + return log_error_errno(r, "Failed to initialize cryptsetup context for %s: %m", dm_name); + else { + log_info("Discovered used LUKS device %s.", dm_node); + + cryptsetup_enable_logging(cd); + + r = crypt_deactivate(cd, dm_name); + if (IN_SET(r, -ENODEV, -EINVAL, -ENOENT)) { + log_debug_errno(r, "LUKS device %s is already detached.", dm_node); + we_detached = false; + } else if (r < 0) + return log_info_errno(r, "LUKS device %s couldn't be deactivated: %m", dm_node); + else { + log_info("LUKS device detaching completed."); + we_detached = true; + } + } + + if (user_record_luks_offline_discard(h)) + log_debug("Not allocating on logout."); + else + (void) run_fallocate_by_path(user_record_image_path(h)); + + run_mark_dirty_by_path(user_record_image_path(h), false); + return we_detached; +} + +int home_trim_luks(UserRecord *h) { + assert(h); + + if (!user_record_luks_offline_discard(h)) { + log_debug("Not trimming on logout."); + return 0; + } + + (void) run_fitrim_by_path(user_record_home_directory(h)); + return 0; +} + +static struct crypt_pbkdf_type* build_good_pbkdf(struct crypt_pbkdf_type *buffer, UserRecord *hr) { + assert(buffer); + assert(hr); + + *buffer = (struct crypt_pbkdf_type) { + .hash = user_record_luks_pbkdf_hash_algorithm(hr), + .type = user_record_luks_pbkdf_type(hr), + .time_ms = user_record_luks_pbkdf_time_cost_usec(hr) / USEC_PER_MSEC, + .max_memory_kb = user_record_luks_pbkdf_memory_cost(hr) / 1024, + .parallel_threads = user_record_luks_pbkdf_parallel_threads(hr), + }; + + return buffer; +} + +static struct crypt_pbkdf_type* build_minimal_pbkdf(struct crypt_pbkdf_type *buffer, UserRecord *hr) { + assert(buffer); + assert(hr); + + /* For PKCS#11 derived keys (which are generated randomly and are of high quality already) we use a + * minimal PBKDF */ + *buffer = (struct crypt_pbkdf_type) { + .hash = user_record_luks_pbkdf_hash_algorithm(hr), + .type = CRYPT_KDF_PBKDF2, + .iterations = 1, + .time_ms = 1, + }; + + return buffer; +} + +static int luks_format( + const char *node, + const char *dm_name, + sd_id128_t uuid, + const char *label, + const PasswordCache *cache, + char **effective_passwords, + bool discard, + UserRecord *hr, + struct crypt_device **ret) { + + _cleanup_(user_record_unrefp) UserRecord *reduced = NULL; + _cleanup_(crypt_freep) struct crypt_device *cd = NULL; + _cleanup_(erase_and_freep) void *volume_key = NULL; + struct crypt_pbkdf_type good_pbkdf, minimal_pbkdf; + char suuid[ID128_UUID_STRING_MAX], **pp; + _cleanup_free_ char *text = NULL; + size_t volume_key_size; + int slot = 0, r; + + assert(node); + assert(dm_name); + assert(hr); + assert(ret); + + r = crypt_init(&cd, node); + if (r < 0) + return log_error_errno(r, "Failed to allocate libcryptsetup context: %m"); + + cryptsetup_enable_logging(cd); + + /* Normally we'd, just leave volume key generation to libcryptsetup. However, we can't, since we + * can't extract the volume key from the library again, but we need it in order to encrypt the JSON + * record. Hence, let's generate it on our own, so that we can keep track of it. */ + + volume_key_size = user_record_luks_volume_key_size(hr); + volume_key = malloc(volume_key_size); + if (!volume_key) + return log_oom(); + + r = genuine_random_bytes(volume_key, volume_key_size, RANDOM_BLOCK); + if (r < 0) + return log_error_errno(r, "Failed to generate volume key: %m"); + +#if HAVE_CRYPT_SET_METADATA_SIZE + /* Increase the metadata space to 4M, the largest LUKS2 supports */ + r = crypt_set_metadata_size(cd, 4096U*1024U, 0); + if (r < 0) + return log_error_errno(r, "Failed to change LUKS2 metadata size: %m"); +#endif + + build_good_pbkdf(&good_pbkdf, hr); + build_minimal_pbkdf(&minimal_pbkdf, hr); + + r = crypt_format(cd, + CRYPT_LUKS2, + user_record_luks_cipher(hr), + user_record_luks_cipher_mode(hr), + id128_to_uuid_string(uuid, suuid), + volume_key, + volume_key_size, + &(struct crypt_params_luks2) { + .label = label, + .subsystem = "systemd-home", + .sector_size = 512U, + .pbkdf = &good_pbkdf, + }); + if (r < 0) + return log_error_errno(r, "Failed to format LUKS image: %m"); + + log_info("LUKS formatting completed."); + + STRV_FOREACH(pp, effective_passwords) { + + if (strv_contains(cache->pkcs11_passwords, *pp) || + strv_contains(cache->fido2_passwords, *pp)) { + log_debug("Using minimal PBKDF for slot %i", slot); + r = crypt_set_pbkdf_type(cd, &minimal_pbkdf); + } else { + log_debug("Using good PBKDF for slot %i", slot); + r = crypt_set_pbkdf_type(cd, &good_pbkdf); + } + if (r < 0) + return log_error_errno(r, "Failed to tweak PBKDF for slot %i: %m", slot); + + r = crypt_keyslot_add_by_volume_key( + cd, + slot, + volume_key, + volume_key_size, + *pp, + strlen(*pp)); + if (r < 0) + return log_error_errno(r, "Failed to set up LUKS password for slot %i: %m", slot); + + log_info("Writing password to LUKS keyslot %i completed.", slot); + slot++; + } + + r = crypt_activate_by_volume_key( + cd, + dm_name, + volume_key, + volume_key_size, + discard ? CRYPT_ACTIVATE_ALLOW_DISCARDS : 0); + if (r < 0) + return log_error_errno(r, "Failed to activate LUKS superblock: %m"); + + log_info("LUKS activation by volume key succeeded."); + + r = user_record_clone(hr, USER_RECORD_EXTRACT_EMBEDDED, &reduced); + if (r < 0) + return log_error_errno(r, "Failed to prepare home record for LUKS: %m"); + + r = format_luks_token_text(cd, reduced, volume_key, &text); + if (r < 0) + return r; + + r = crypt_token_json_set(cd, CRYPT_ANY_TOKEN, text); + if (r < 0) + return log_error_errno(r, "Failed to set LUKS JSON token: %m"); + + log_info("Writing user record as LUKS token completed."); + + if (ret) + *ret = TAKE_PTR(cd); + + return 0; +} + +DEFINE_TRIVIAL_CLEANUP_FUNC(struct fdisk_context*, fdisk_unref_context); +DEFINE_TRIVIAL_CLEANUP_FUNC(struct fdisk_partition*, fdisk_unref_partition); +DEFINE_TRIVIAL_CLEANUP_FUNC(struct fdisk_parttype*, fdisk_unref_parttype); +DEFINE_TRIVIAL_CLEANUP_FUNC(struct fdisk_table*, fdisk_unref_table); + +static int make_partition_table( + int fd, + const char *label, + sd_id128_t uuid, + uint64_t *ret_offset, + uint64_t *ret_size, + sd_id128_t *ret_disk_uuid) { + + _cleanup_(fdisk_unref_partitionp) struct fdisk_partition *p = NULL, *q = NULL; + _cleanup_(fdisk_unref_parttypep) struct fdisk_parttype *t = NULL; + _cleanup_(fdisk_unref_contextp) struct fdisk_context *c = NULL; + _cleanup_free_ char *path = NULL, *disk_uuid_as_string = NULL; + uint64_t offset, size; + sd_id128_t disk_uuid; + char uuids[ID128_UUID_STRING_MAX]; + int r; + + assert(fd >= 0); + assert(label); + assert(ret_offset); + assert(ret_size); + + t = fdisk_new_parttype(); + if (!t) + return log_oom(); + + r = fdisk_parttype_set_typestr(t, "773f91ef-66d4-49b5-bd83-d683bf40ad16"); + if (r < 0) + return log_error_errno(r, "Failed to initialize partition type: %m"); + + c = fdisk_new_context(); + if (!c) + return log_oom(); + + if (asprintf(&path, "/proc/self/fd/%i", fd) < 0) + return log_oom(); + + r = fdisk_assign_device(c, path, 0); + if (r < 0) + return log_error_errno(r, "Failed to open device: %m"); + + r = fdisk_create_disklabel(c, "gpt"); + if (r < 0) + return log_error_errno(r, "Failed to create GPT disk label: %m"); + + p = fdisk_new_partition(); + if (!p) + return log_oom(); + + r = fdisk_partition_set_type(p, t); + if (r < 0) + return log_error_errno(r, "Failed to set partition type: %m"); + + r = fdisk_partition_start_follow_default(p, 1); + if (r < 0) + return log_error_errno(r, "Failed to place partition at beginning of space: %m"); + + r = fdisk_partition_partno_follow_default(p, 1); + if (r < 0) + return log_error_errno(r, "Failed to place partition at first free partition index: %m"); + + r = fdisk_partition_end_follow_default(p, 1); + if (r < 0) + return log_error_errno(r, "Failed to make partition cover all free space: %m"); + + r = fdisk_partition_set_name(p, label); + if (r < 0) + return log_error_errno(r, "Failed to set partition name: %m"); + + r = fdisk_partition_set_uuid(p, id128_to_uuid_string(uuid, uuids)); + if (r < 0) + return log_error_errno(r, "Failed to set partition UUID: %m"); + + r = fdisk_add_partition(c, p, NULL); + if (r < 0) + return log_error_errno(r, "Failed to add partition: %m"); + + r = fdisk_write_disklabel(c); + if (r < 0) + return log_error_errno(r, "Failed to write disk label: %m"); + + r = fdisk_get_disklabel_id(c, &disk_uuid_as_string); + if (r < 0) + return log_error_errno(r, "Failed to determine disk label UUID: %m"); + + r = sd_id128_from_string(disk_uuid_as_string, &disk_uuid); + if (r < 0) + return log_error_errno(r, "Failed to parse disk label UUID: %m"); + + r = fdisk_get_partition(c, 0, &q); + if (r < 0) + return log_error_errno(r, "Failed to read created partition metadata: %m"); + + assert(fdisk_partition_has_start(q)); + offset = fdisk_partition_get_start(q); + if (offset > UINT64_MAX / 512U) + return log_error_errno(SYNTHETIC_ERRNO(ERANGE), "Partition offset too large."); + + assert(fdisk_partition_has_size(q)); + size = fdisk_partition_get_size(q); + if (size > UINT64_MAX / 512U) + return log_error_errno(SYNTHETIC_ERRNO(ERANGE), "Partition size too large."); + + *ret_offset = offset * 512U; + *ret_size = size * 512U; + *ret_disk_uuid = disk_uuid; + + return 0; +} + +static bool supported_fs_size(const char *fstype, uint64_t host_size) { + uint64_t m; + + m = minimal_size_by_fs_name(fstype); + if (m == UINT64_MAX) + return false; + + return host_size >= m; +} + +static int wait_for_devlink(const char *path) { + _cleanup_close_ int inotify_fd = -1; + usec_t until; + int r; + + /* let's wait for a device link to show up in /dev, with a timeout. This is good to do since we + * return a /dev/disk/by-uuid/… link to our callers and they likely want to access it right-away, + * hence let's wait until udev has caught up with our changes, and wait for the symlink to be + * created. */ + + until = usec_add(now(CLOCK_MONOTONIC), 45 * USEC_PER_SEC); + + for (;;) { + _cleanup_free_ char *dn = NULL; + usec_t w; + + if (laccess(path, F_OK) < 0) { + if (errno != ENOENT) + return log_error_errno(errno, "Failed to determine whether %s exists: %m", path); + } else + return 0; /* Found it */ + + if (inotify_fd < 0) { + /* We need to wait for the device symlink to show up, let's create an inotify watch for it */ + inotify_fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC); + if (inotify_fd < 0) + return log_error_errno(errno, "Failed to allocate inotify fd: %m"); + } + + dn = dirname_malloc(path); + for (;;) { + if (!dn) + return log_oom(); + + log_info("Watching %s", dn); + + if (inotify_add_watch(inotify_fd, dn, IN_CREATE|IN_MOVED_TO|IN_ONLYDIR|IN_DELETE_SELF|IN_MOVE_SELF) < 0) { + if (errno != ENOENT) + return log_error_errno(errno, "Failed to add watch on %s: %m", dn); + } else + break; + + if (empty_or_root(dn)) + break; + + dn = dirname_malloc(dn); + } + + w = now(CLOCK_MONOTONIC); + if (w >= until) + return log_error_errno(SYNTHETIC_ERRNO(ETIMEDOUT), "Device link %s still hasn't shown up, giving up.", path); + + r = fd_wait_for_event(inotify_fd, POLLIN, usec_sub_unsigned(until, w)); + if (r < 0) + return log_error_errno(r, "Failed to watch inotify: %m"); + + (void) flush_fd(inotify_fd); + } +} + +static int calculate_disk_size(UserRecord *h, const char *parent_dir, uint64_t *ret) { + char buf[FORMAT_BYTES_MAX]; + struct statfs sfs; + uint64_t m; + + assert(h); + assert(parent_dir); + assert(ret); + + if (h->disk_size != UINT64_MAX) { + *ret = DISK_SIZE_ROUND_DOWN(h->disk_size); + return 0; + } + + if (statfs(parent_dir, &sfs) < 0) + return log_error_errno(errno, "statfs() on %s failed: %m", parent_dir); + + m = sfs.f_bsize * sfs.f_bavail; + + if (h->disk_size_relative == UINT64_MAX) { + + if (m > UINT64_MAX / USER_DISK_SIZE_DEFAULT_PERCENT) + return log_error_errno(SYNTHETIC_ERRNO(EOVERFLOW), "Disk size too large."); + + *ret = DISK_SIZE_ROUND_DOWN(m * USER_DISK_SIZE_DEFAULT_PERCENT / 100); + + log_info("Sizing home to %u%% of available disk space, which is %s.", + USER_DISK_SIZE_DEFAULT_PERCENT, + format_bytes(buf, sizeof(buf), *ret)); + } else { + *ret = DISK_SIZE_ROUND_DOWN((uint64_t) ((double) m * (double) h->disk_size_relative / (double) UINT32_MAX)); + + log_info("Sizing home to %" PRIu64 ".%01" PRIu64 "%% of available disk space, which is %s.", + (h->disk_size_relative * 100) / UINT32_MAX, + ((h->disk_size_relative * 1000) / UINT32_MAX) % 10, + format_bytes(buf, sizeof(buf), *ret)); + } + + if (*ret < USER_DISK_SIZE_MIN) + *ret = USER_DISK_SIZE_MIN; + + return 0; +} + +static int home_truncate( + UserRecord *h, + int fd, + const char *path, + uint64_t size) { + + bool trunc; + int r; + + assert(h); + assert(fd >= 0); + assert(path); + + trunc = user_record_luks_discard(h); + if (!trunc) { + r = fallocate(fd, 0, 0, size); + if (r < 0 && ERRNO_IS_NOT_SUPPORTED(errno)) { + /* Some file systems do not support fallocate(), let's gracefully degrade + * (ZFS, reiserfs, …) and fall back to truncation */ + log_notice_errno(errno, "Backing file system does not support fallocate(), falling back to ftruncate(), i.e. implicitly using non-discard mode."); + trunc = true; + } + } + + if (trunc) + r = ftruncate(fd, size); + + if (r < 0) { + if (ERRNO_IS_DISK_SPACE(errno)) { + log_error_errno(errno, "Not enough disk space to allocate home."); + return -ENOSPC; /* make recognizable */ + } + + return log_error_errno(errno, "Failed to truncate home image %s: %m", path); + } + + return 0; +} + +int home_create_luks( + UserRecord *h, + PasswordCache *cache, + char **effective_passwords, + UserRecord **ret_home) { + + _cleanup_free_ char *dm_name = NULL, *dm_node = NULL, *subdir = NULL, *disk_uuid_path = NULL, *temporary_image_path = NULL; + uint64_t host_size, encrypted_size, partition_offset, partition_size; + bool image_created = false, dm_activated = false, mounted = false; + _cleanup_(user_record_unrefp) UserRecord *new_home = NULL; + sd_id128_t partition_uuid, fs_uuid, luks_uuid, disk_uuid; + _cleanup_(loop_device_unrefp) LoopDevice *loop = NULL; + _cleanup_(crypt_freep) struct crypt_device *cd = NULL; + _cleanup_close_ int image_fd = -1, root_fd = -1; + const char *fstype, *ip; + struct statfs sfs; + int r; + + assert(h); + assert(h->storage < 0 || h->storage == USER_LUKS); + assert(ret_home); + + assert_se(ip = user_record_image_path(h)); + + fstype = user_record_file_system_type(h); + if (!supported_fstype(fstype)) + return log_error_errno(SYNTHETIC_ERRNO(EPROTONOSUPPORT), "Unsupported file system type: %s", fstype); + + r = mkfs_exists(fstype); + if (r < 0) + return log_error_errno(r, "Failed to check if mkfs binary for %s exists: %m", fstype); + if (r == 0) { + if (h->file_system_type || streq(fstype, "ext4") || !supported_fstype("ext4")) + return log_error_errno(SYNTHETIC_ERRNO(EPROTONOSUPPORT), "mkfs binary for file system type %s does not exist.", fstype); + + /* If the record does not explicitly declare a file system to use, and the compiled-in + * default does not actually exist, than do an automatic fallback onto ext4, as the baseline + * fs of Linux. We won't search for a working fs type here beyond ext4, i.e. nothing fancier + * than a single, conservative fallback to baseline. This should be useful in minimal + * environments where mkfs.btrfs or so are not made available, but mkfs.ext4 as Linux' most + * boring, most basic fs is. */ + log_info("Formatting tool for compiled-in default file system %s not available, falling back to ext4 instead.", fstype); + fstype = "ext4"; + } + + if (sd_id128_is_null(h->partition_uuid)) { + r = sd_id128_randomize(&partition_uuid); + if (r < 0) + return log_error_errno(r, "Failed to acquire partition UUID: %m"); + } else + partition_uuid = h->partition_uuid; + + if (sd_id128_is_null(h->luks_uuid)) { + r = sd_id128_randomize(&luks_uuid); + if (r < 0) + return log_error_errno(r, "Failed to acquire LUKS UUID: %m"); + } else + luks_uuid = h->luks_uuid; + + if (sd_id128_is_null(h->file_system_uuid)) { + r = sd_id128_randomize(&fs_uuid); + if (r < 0) + return log_error_errno(r, "Failed to acquire file system UUID: %m"); + } else + fs_uuid = h->file_system_uuid; + + r = make_dm_names(h->user_name, &dm_name, &dm_node); + if (r < 0) + return r; + + r = access(dm_node, F_OK); + if (r < 0) { + if (errno != ENOENT) + return log_error_errno(errno, "Failed to determine whether %s exists: %m", dm_node); + } else + return log_error_errno(SYNTHETIC_ERRNO(EEXIST), "Device mapper device %s already exists, refusing.", dm_node); + + if (path_startswith(ip, "/dev/")) { + _cleanup_free_ char *sysfs = NULL; + uint64_t block_device_size; + struct stat st; + + /* Let's place the home directory on a real device, i.e. an USB stick or such */ + + image_fd = open(ip, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK); + if (image_fd < 0) + return log_error_errno(errno, "Failed to open device %s: %m", ip); + + if (fstat(image_fd, &st) < 0) + return log_error_errno(errno, "Failed to stat device %s: %m", ip); + if (!S_ISBLK(st.st_mode)) + return log_error_errno(SYNTHETIC_ERRNO(ENOTBLK), "Device is not a block device, refusing."); + + if (asprintf(&sysfs, "/sys/dev/block/%u:%u/partition", major(st.st_rdev), minor(st.st_rdev)) < 0) + return log_oom(); + if (access(sysfs, F_OK) < 0) { + if (errno != ENOENT) + return log_error_errno(errno, "Failed to check whether %s exists: %m", sysfs); + } else + return log_error_errno(SYNTHETIC_ERRNO(ENOTBLK), "Operating on partitions is currently not supported, sorry. Please specify a top-level block device."); + + if (flock(image_fd, LOCK_EX) < 0) /* make sure udev doesn't read from it while we operate on the device */ + return log_error_errno(errno, "Failed to lock block device %s: %m", ip); + + if (ioctl(image_fd, BLKGETSIZE64, &block_device_size) < 0) + return log_error_errno(errno, "Failed to read block device size: %m"); + + if (h->disk_size == UINT64_MAX) { + + /* If a relative disk size is requested, apply it relative to the block device size */ + if (h->disk_size_relative < UINT32_MAX) + host_size = CLAMP(DISK_SIZE_ROUND_DOWN(block_device_size * h->disk_size_relative / UINT32_MAX), + USER_DISK_SIZE_MIN, USER_DISK_SIZE_MAX); + else + host_size = block_device_size; /* Otherwise, take the full device */ + + } else if (h->disk_size > block_device_size) + return log_error_errno(SYNTHETIC_ERRNO(EMSGSIZE), "Selected disk size larger than backing block device, refusing."); + else + host_size = DISK_SIZE_ROUND_DOWN(h->disk_size); + + if (!supported_fs_size(fstype, host_size)) + return log_error_errno(SYNTHETIC_ERRNO(ERANGE), + "Selected file system size too small for %s.", fstype); + + /* After creation we should reference this partition by its UUID instead of the block + * device. That's preferable since the user might have specified a device node such as + * /dev/sdb to us, which might look very different when replugged. */ + if (asprintf(&disk_uuid_path, "/dev/disk/by-uuid/" SD_ID128_UUID_FORMAT_STR, SD_ID128_FORMAT_VAL(luks_uuid)) < 0) + return log_oom(); + + if (user_record_luks_discard(h) || user_record_luks_offline_discard(h)) { + /* If we want online or offline discard, discard once before we start using things. */ + + if (ioctl(image_fd, BLKDISCARD, (uint64_t[]) { 0, block_device_size }) < 0) + log_full_errno(errno == EOPNOTSUPP ? LOG_DEBUG : LOG_WARNING, errno, + "Failed to issue full-device BLKDISCARD on device, ignoring: %m"); + else + log_info("Full device discard completed."); + } + } else { + _cleanup_free_ char *parent = NULL; + + parent = dirname_malloc(ip); + if (!parent) + return log_oom(); + + r = mkdir_p(parent, 0755); + if (r < 0) + return log_error_errno(r, "Failed to create parent directory %s: %m", parent); + + r = calculate_disk_size(h, parent, &host_size); + if (r < 0) + return r; + + if (!supported_fs_size(fstype, host_size)) + return log_error_errno(SYNTHETIC_ERRNO(ERANGE), "Selected file system size too small for %s.", fstype); + + r = tempfn_random(ip, "homework", &temporary_image_path); + if (r < 0) + return log_error_errno(r, "Failed to derive temporary file name for %s: %m", ip); + + image_fd = open(temporary_image_path, O_RDWR|O_CREAT|O_EXCL|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, 0600); + if (image_fd < 0) + return log_error_errno(errno, "Failed to create home image %s: %m", temporary_image_path); + + image_created = true; + + r = chattr_fd(image_fd, FS_NOCOW_FL, FS_NOCOW_FL, NULL); + if (r < 0) + log_full_errno(ERRNO_IS_NOT_SUPPORTED(r) ? LOG_DEBUG : LOG_WARNING, r, + "Failed to set file attributes on %s, ignoring: %m", temporary_image_path); + + r = home_truncate(h, image_fd, temporary_image_path, host_size); + if (r < 0) + goto fail; + + log_info("Allocating image file completed."); + } + + r = make_partition_table( + image_fd, + user_record_user_name_and_realm(h), + partition_uuid, + &partition_offset, + &partition_size, + &disk_uuid); + if (r < 0) + goto fail; + + log_info("Writing of partition table completed."); + + r = loop_device_make(image_fd, O_RDWR, partition_offset, partition_size, 0, &loop); + if (r < 0) { + if (r == -ENOENT) { /* this means /dev/loop-control doesn't exist, i.e. we are in a container + * or similar and loopback bock devices are not available, return a + * recognizable error in this case. */ + log_error_errno(r, "Loopback block device support is not available on this system."); + r = -ENOLINK; + goto fail; + } + + log_error_errno(r, "Failed to set up loopback device for %s: %m", temporary_image_path); + goto fail; + } + + r = loop_device_flock(loop, LOCK_EX); /* make sure udev won't read before we are done */ + if (r < 0) { + log_error_errno(r, "Failed to take lock on loop device: %m"); + goto fail; + } + + log_info("Setting up loopback device %s completed.", loop->node ?: ip); + + r = luks_format(loop->node, + dm_name, + luks_uuid, + user_record_user_name_and_realm(h), + cache, + effective_passwords, + user_record_luks_discard(h) || user_record_luks_offline_discard(h), + h, + &cd); + if (r < 0) + goto fail; + + dm_activated = true; + + r = block_get_size_by_path(dm_node, &encrypted_size); + if (r < 0) { + log_error_errno(r, "Failed to get encrypted block device size: %m"); + goto fail; + } + + log_info("Setting up LUKS device %s completed.", dm_node); + + r = make_filesystem(dm_node, fstype, user_record_user_name_and_realm(h), fs_uuid, user_record_luks_discard(h)); + if (r < 0) + goto fail; + + log_info("Formatting file system completed."); + + r = home_unshare_and_mount(dm_node, fstype, user_record_luks_discard(h), user_record_mount_flags(h)); + if (r < 0) + goto fail; + + mounted = true; + + subdir = path_join("/run/systemd/user-home-mount/", user_record_user_name_and_realm(h)); + if (!subdir) { + r = log_oom(); + goto fail; + } + + /* Prefer using a btrfs subvolume if we can, fall back to directory otherwise */ + r = btrfs_subvol_make_fallback(subdir, 0700); + if (r < 0) { + log_error_errno(r, "Failed to create user directory in mounted image file: %m"); + goto fail; + } + + root_fd = open(subdir, O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW); + if (root_fd < 0) { + r = log_error_errno(errno, "Failed to open user directory in mounted image file: %m"); + goto fail; + } + + r = home_populate(h, root_fd); + if (r < 0) + goto fail; + + r = home_sync_and_statfs(root_fd, &sfs); + if (r < 0) + goto fail; + + r = user_record_clone(h, USER_RECORD_LOAD_MASK_SECRET|USER_RECORD_LOG, &new_home); + if (r < 0) { + log_error_errno(r, "Failed to clone record: %m"); + goto fail; + } + + r = user_record_add_binding( + new_home, + USER_LUKS, + disk_uuid_path ?: ip, + partition_uuid, + luks_uuid, + fs_uuid, + crypt_get_cipher(cd), + crypt_get_cipher_mode(cd), + luks_volume_key_size_convert(cd), + fstype, + NULL, + h->uid, + (gid_t) h->uid); + if (r < 0) { + log_error_errno(r, "Failed to add binding to record: %m"); + goto fail; + } + + if (user_record_luks_offline_discard(h)) { + r = run_fitrim(root_fd); + if (r < 0) + goto fail; + } + + root_fd = safe_close(root_fd); + + r = umount_verbose(LOG_ERR, "/run/systemd/user-home-mount", UMOUNT_NOFOLLOW); + if (r < 0) + goto fail; + + mounted = false; + + r = crypt_deactivate(cd, dm_name); + if (r < 0) { + log_error_errno(r, "Failed to deactivate LUKS device: %m"); + goto fail; + } + + crypt_free(cd); + cd = NULL; + + dm_activated = false; + + loop = loop_device_unref(loop); + + if (!user_record_luks_offline_discard(h)) { + r = run_fallocate(image_fd, NULL /* refresh stat() data */); + if (r < 0) + goto fail; + } + + /* Sync everything to disk before we move things into place under the final name. */ + if (fsync(image_fd) < 0) { + r = log_error_errno(r, "Failed to synchronize image to disk: %m"); + goto fail; + } + + if (disk_uuid_path) + (void) ioctl(image_fd, BLKRRPART, 0); + else { + /* If we operate on a file, sync the containing directory too. */ + r = fsync_directory_of_file(image_fd); + if (r < 0) { + log_error_errno(r, "Failed to synchronize directory of image file to disk: %m"); + goto fail; + } + } + + /* Let's close the image fd now. If we are operating on a real block device this will release the BSD + * lock that ensures udev doesn't interfere with what we are doing */ + image_fd = safe_close(image_fd); + + if (temporary_image_path) { + if (rename(temporary_image_path, ip) < 0) { + log_error_errno(errno, "Failed to rename image file: %m"); + goto fail; + } + + log_info("Moved image file into place."); + } + + if (disk_uuid_path) + (void) wait_for_devlink(disk_uuid_path); + + log_info("Everything completed."); + + print_size_summary(host_size, encrypted_size, &sfs); + + *ret_home = TAKE_PTR(new_home); + return 0; + +fail: + /* Let's close all files before we unmount the file system, to avoid EBUSY */ + root_fd = safe_close(root_fd); + + if (mounted) + (void) umount_verbose(LOG_WARNING, "/run/systemd/user-home-mount", UMOUNT_NOFOLLOW); + + if (dm_activated) + (void) crypt_deactivate(cd, dm_name); + + loop = loop_device_unref(loop); + + if (image_created) + (void) unlink(temporary_image_path); + + return r; +} + +int home_validate_update_luks(UserRecord *h, HomeSetup *setup) { + _cleanup_free_ char *dm_name = NULL, *dm_node = NULL; + int r; + + assert(h); + assert(setup); + + r = make_dm_names(h->user_name, &dm_name, &dm_node); + if (r < 0) + return r; + + r = access(dm_node, F_OK); + if (r < 0 && errno != ENOENT) + return log_error_errno(errno, "Failed to determine whether %s exists: %m", dm_node); + + free_and_replace(setup->dm_name, dm_name); + free_and_replace(setup->dm_node, dm_node); + + return r >= 0; +} + +enum { + CAN_RESIZE_ONLINE, + CAN_RESIZE_OFFLINE, +}; + +static int can_resize_fs(int fd, uint64_t old_size, uint64_t new_size) { + struct statfs sfs; + + assert(fd >= 0); + + /* Filter out bogus requests early */ + if (old_size == 0 || old_size == UINT64_MAX || + new_size == 0 || new_size == UINT64_MAX) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Invalid resize parameters."); + + if ((old_size & 511) != 0 || (new_size & 511) != 0) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Resize parameters not multiple of 512."); + + if (fstatfs(fd, &sfs) < 0) + return log_error_errno(errno, "Failed to fstatfs() file system: %m"); + + if (is_fs_type(&sfs, BTRFS_SUPER_MAGIC)) { + + if (new_size < BTRFS_MINIMAL_SIZE) + return log_error_errno(SYNTHETIC_ERRNO(ERANGE), "New file system size too small for btrfs (needs to be 256M at least."); + + /* btrfs can grow and shrink online */ + + } else if (is_fs_type(&sfs, XFS_SB_MAGIC)) { + + if (new_size < XFS_MINIMAL_SIZE) + return log_error_errno(SYNTHETIC_ERRNO(ERANGE), "New file system size too small for xfs (needs to be 14M at least)."); + + /* XFS can grow, but not shrink */ + if (new_size < old_size) + return log_error_errno(SYNTHETIC_ERRNO(EMSGSIZE), "Shrinking this type of file system is not supported."); + + } else if (is_fs_type(&sfs, EXT4_SUPER_MAGIC)) { + + if (new_size < EXT4_MINIMAL_SIZE) + return log_error_errno(SYNTHETIC_ERRNO(ERANGE), "New file system size too small for ext4 (needs to be 1M at least)."); + + /* ext4 can grow online, and shrink offline */ + if (new_size < old_size) + return CAN_RESIZE_OFFLINE; + + } else + return log_error_errno(SYNTHETIC_ERRNO(ESOCKTNOSUPPORT), "Resizing this type of file system is not supported."); + + return CAN_RESIZE_ONLINE; +} + +static int ext4_offline_resize_fs(HomeSetup *setup, uint64_t new_size, bool discard, unsigned long flags) { + _cleanup_free_ char *size_str = NULL; + bool re_open = false, re_mount = false; + pid_t resize_pid, fsck_pid; + int r, exit_status; + + assert(setup); + assert(setup->dm_node); + + /* First, unmount the file system */ + if (setup->root_fd >= 0) { + setup->root_fd = safe_close(setup->root_fd); + re_open = true; + } + + if (setup->undo_mount) { + r = umount_verbose(LOG_ERR, "/run/systemd/user-home-mount", UMOUNT_NOFOLLOW); + if (r < 0) + return r; + + setup->undo_mount = false; + re_mount = true; + } + + log_info("Temporary unmounting of file system completed."); + + /* resize2fs requires that the file system is force checked first, do so. */ + r = safe_fork("(e2fsck)", FORK_RESET_SIGNALS|FORK_RLIMIT_NOFILE_SAFE|FORK_DEATHSIG|FORK_LOG|FORK_STDOUT_TO_STDERR, &fsck_pid); + if (r < 0) + return r; + if (r == 0) { + /* Child */ + execlp("e2fsck" ,"e2fsck", "-fp", setup->dm_node, NULL); + log_error_errno(errno, "Failed to execute e2fsck: %m"); + _exit(EXIT_FAILURE); + } + + exit_status = wait_for_terminate_and_check("e2fsck", fsck_pid, WAIT_LOG_ABNORMAL); + if (exit_status < 0) + return exit_status; + if ((exit_status & ~FSCK_ERROR_CORRECTED) != 0) { + log_warning("e2fsck failed with exit status %i.", exit_status); + + if ((exit_status & (FSCK_SYSTEM_SHOULD_REBOOT|FSCK_ERRORS_LEFT_UNCORRECTED)) != 0) + return log_error_errno(SYNTHETIC_ERRNO(EIO), "File system is corrupted, refusing."); + + log_warning("Ignoring fsck error."); + } + + log_info("Forced file system check completed."); + + /* We use 512 sectors here, because resize2fs doesn't do byte sizes */ + if (asprintf(&size_str, "%" PRIu64 "s", new_size / 512) < 0) + return log_oom(); + + /* Resize the thing */ + r = safe_fork("(e2resize)", FORK_RESET_SIGNALS|FORK_RLIMIT_NOFILE_SAFE|FORK_DEATHSIG|FORK_LOG|FORK_WAIT|FORK_STDOUT_TO_STDERR, &resize_pid); + if (r < 0) + return r; + if (r == 0) { + /* Child */ + execlp("resize2fs" ,"resize2fs", setup->dm_node, size_str, NULL); + log_error_errno(errno, "Failed to execute resize2fs: %m"); + _exit(EXIT_FAILURE); + } + + log_info("Offline file system resize completed."); + + /* Re-establish mounts and reopen the directory */ + if (re_mount) { + r = home_mount_node(setup->dm_node, "ext4", discard, flags); + if (r < 0) + return r; + + setup->undo_mount = true; + } + + if (re_open) { + setup->root_fd = open("/run/systemd/user-home-mount", O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW); + if (setup->root_fd < 0) + return log_error_errno(errno, "Failed to reopen file system: %m"); + } + + log_info("File system mounted again."); + + return 0; +} + +static int prepare_resize_partition( + int fd, + uint64_t partition_offset, + uint64_t old_partition_size, + uint64_t new_partition_size, + sd_id128_t *ret_disk_uuid, + struct fdisk_table **ret_table) { + + _cleanup_(fdisk_unref_contextp) struct fdisk_context *c = NULL; + _cleanup_(fdisk_unref_tablep) struct fdisk_table *t = NULL; + _cleanup_free_ char *path = NULL, *disk_uuid_as_string = NULL; + size_t n_partitions, i; + sd_id128_t disk_uuid; + bool found = false; + int r; + + assert(fd >= 0); + assert(ret_disk_uuid); + assert(ret_table); + + assert((partition_offset & 511) == 0); + assert((old_partition_size & 511) == 0); + assert((new_partition_size & 511) == 0); + assert(UINT64_MAX - old_partition_size >= partition_offset); + assert(UINT64_MAX - new_partition_size >= partition_offset); + + if (partition_offset == 0) { + /* If the offset is at the beginning we assume no partition table, let's exit early. */ + log_debug("Not rewriting partition table, operating on naked device."); + *ret_disk_uuid = SD_ID128_NULL; + *ret_table = NULL; + return 0; + } + + c = fdisk_new_context(); + if (!c) + return log_oom(); + + if (asprintf(&path, "/proc/self/fd/%i", fd) < 0) + return log_oom(); + + r = fdisk_assign_device(c, path, 0); + if (r < 0) + return log_error_errno(r, "Failed to open device: %m"); + + if (!fdisk_is_labeltype(c, FDISK_DISKLABEL_GPT)) + return log_error_errno(SYNTHETIC_ERRNO(ENOMEDIUM), "Disk has no GPT partition table."); + + r = fdisk_get_disklabel_id(c, &disk_uuid_as_string); + if (r < 0) + return log_error_errno(r, "Failed to acquire disk UUID: %m"); + + r = sd_id128_from_string(disk_uuid_as_string, &disk_uuid); + if (r < 0) + return log_error_errno(r, "Failed parse disk UUID: %m"); + + r = fdisk_get_partitions(c, &t); + if (r < 0) + return log_error_errno(r, "Failed to acquire partition table: %m"); + + n_partitions = fdisk_table_get_nents(t); + for (i = 0; i < n_partitions; i++) { + struct fdisk_partition *p; + + p = fdisk_table_get_partition(t, i); + if (!p) + return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to read partition metadata: %m"); + + if (fdisk_partition_is_used(p) <= 0) + continue; + if (fdisk_partition_has_start(p) <= 0 || fdisk_partition_has_size(p) <= 0 || fdisk_partition_has_end(p) <= 0) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Found partition without a size."); + + if (fdisk_partition_get_start(p) == partition_offset / 512U && + fdisk_partition_get_size(p) == old_partition_size / 512U) { + + if (found) + return log_error_errno(SYNTHETIC_ERRNO(ENOTUNIQ), "Partition found twice, refusing."); + + /* Found our partition, now patch it */ + r = fdisk_partition_size_explicit(p, 1); + if (r < 0) + return log_error_errno(r, "Failed to enable explicit partition size: %m"); + + r = fdisk_partition_set_size(p, new_partition_size / 512U); + if (r < 0) + return log_error_errno(r, "Failed to change partition size: %m"); + + found = true; + continue; + + } else { + if (fdisk_partition_get_start(p) < partition_offset + new_partition_size / 512U && + fdisk_partition_get_end(p) >= partition_offset / 512) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Can't extend, conflicting partition found."); + } + } + + if (!found) + return log_error_errno(SYNTHETIC_ERRNO(ENOPKG), "Failed to find matching partition to resize."); + + *ret_table = TAKE_PTR(t); + *ret_disk_uuid = disk_uuid; + + return 1; +} + +static int ask_cb(struct fdisk_context *c, struct fdisk_ask *ask, void *userdata) { + char *result; + + assert(c); + + switch (fdisk_ask_get_type(ask)) { + + case FDISK_ASKTYPE_STRING: + result = new(char, 37); + if (!result) + return log_oom(); + + fdisk_ask_string_set_result(ask, id128_to_uuid_string(*(sd_id128_t*) userdata, result)); + break; + + default: + log_debug("Unexpected question from libfdisk, ignoring."); + } + + return 0; +} + +static int apply_resize_partition(int fd, sd_id128_t disk_uuids, struct fdisk_table *t) { + _cleanup_(fdisk_unref_contextp) struct fdisk_context *c = NULL; + _cleanup_free_ void *two_zero_lbas = NULL; + _cleanup_free_ char *path = NULL; + ssize_t n; + int r; + + assert(fd >= 0); + + if (!t) /* no partition table to apply, exit early */ + return 0; + + two_zero_lbas = malloc0(1024U); + if (!two_zero_lbas) + return log_oom(); + + /* libfdisk appears to get confused by the existing PMBR. Let's explicitly flush it out. */ + n = pwrite(fd, two_zero_lbas, 1024U, 0); + if (n < 0) + return log_error_errno(errno, "Failed to wipe partition table: %m"); + if (n != 1024) + return log_error_errno(SYNTHETIC_ERRNO(EIO), "Short write while wiping partition table."); + + c = fdisk_new_context(); + if (!c) + return log_oom(); + + if (asprintf(&path, "/proc/self/fd/%i", fd) < 0) + return log_oom(); + + r = fdisk_assign_device(c, path, 0); + if (r < 0) + return log_error_errno(r, "Failed to open device: %m"); + + r = fdisk_create_disklabel(c, "gpt"); + if (r < 0) + return log_error_errno(r, "Failed to create GPT disk label: %m"); + + r = fdisk_apply_table(c, t); + if (r < 0) + return log_error_errno(r, "Failed to apply partition table: %m"); + + r = fdisk_set_ask(c, ask_cb, &disk_uuids); + if (r < 0) + return log_error_errno(r, "Failed to set libfdisk query function: %m"); + + r = fdisk_set_disklabel_id(c); + if (r < 0) + return log_error_errno(r, "Failed to change disklabel ID: %m"); + + r = fdisk_write_disklabel(c); + if (r < 0) + return log_error_errno(r, "Failed to write disk label: %m"); + + return 1; +} + +int home_resize_luks( + UserRecord *h, + bool already_activated, + PasswordCache *cache, + HomeSetup *setup, + UserRecord **ret_home) { + + char buffer1[FORMAT_BYTES_MAX], buffer2[FORMAT_BYTES_MAX], buffer3[FORMAT_BYTES_MAX], + buffer4[FORMAT_BYTES_MAX], buffer5[FORMAT_BYTES_MAX], buffer6[FORMAT_BYTES_MAX]; + uint64_t old_image_size, new_image_size, old_fs_size, new_fs_size, crypto_offset, new_partition_size; + _cleanup_(user_record_unrefp) UserRecord *header_home = NULL, *embedded_home = NULL, *new_home = NULL; + _cleanup_(fdisk_unref_tablep) struct fdisk_table *table = NULL; + _cleanup_free_ char *whole_disk = NULL; + _cleanup_close_ int image_fd = -1; + sd_id128_t disk_uuid; + const char *ip, *ipo; + struct statfs sfs; + struct stat st; + int r, resize_type; + + assert(h); + assert(user_record_storage(h) == USER_LUKS); + assert(setup); + assert(ret_home); + + assert_se(ipo = user_record_image_path(h)); + ip = strdupa(ipo); /* copy out since original might change later in home record object */ + + image_fd = open(ip, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK); + if (image_fd < 0) + return log_error_errno(errno, "Failed to open image file %s: %m", ip); + + if (fstat(image_fd, &st) < 0) + return log_error_errno(errno, "Failed to stat image file %s: %m", ip); + if (S_ISBLK(st.st_mode)) { + dev_t parent; + + r = block_get_whole_disk(st.st_rdev, &parent); + if (r < 0) + return log_error_errno(r, "Failed to acquire whole block device for %s: %m", ip); + if (r > 0) { + /* If we shall resize a file system on a partition device, then let's figure out the + * whole disk device and operate on that instead, since we need to rewrite the + * partition table to resize the partition. */ + + log_info("Operating on partition device %s, using parent device.", ip); + + r = device_path_make_major_minor(st.st_mode, parent, &whole_disk); + if (r < 0) + return log_error_errno(r, "Failed to derive whole disk path for %s: %m", ip); + + safe_close(image_fd); + + image_fd = open(whole_disk, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK); + if (image_fd < 0) + return log_error_errno(errno, "Failed to open whole block device %s: %m", whole_disk); + + if (fstat(image_fd, &st) < 0) + return log_error_errno(errno, "Failed to stat whole block device %s: %m", whole_disk); + if (!S_ISBLK(st.st_mode)) + return log_error_errno(SYNTHETIC_ERRNO(ENOTBLK), "Whole block device %s is not actually a block device, refusing.", whole_disk); + } else + log_info("Operating on whole block device %s.", ip); + + if (ioctl(image_fd, BLKGETSIZE64, &old_image_size) < 0) + return log_error_errno(errno, "Failed to determine size of original block device: %m"); + + if (flock(image_fd, LOCK_EX) < 0) /* make sure udev doesn't read from it while we operate on the device */ + return log_error_errno(errno, "Failed to lock block device %s: %m", ip); + + new_image_size = old_image_size; /* we can't resize physical block devices */ + } else { + r = stat_verify_regular(&st); + if (r < 0) + return log_error_errno(r, "Image %s is not a block device nor regular file: %m", ip); + + old_image_size = st.st_size; + + /* Note an asymetry here: when we operate on loopback files the specified disk size we get we + * apply onto the loopback file as a whole. When we operate on block devices we instead apply + * to the partition itself only. */ + + new_image_size = DISK_SIZE_ROUND_DOWN(h->disk_size); + if (new_image_size == old_image_size) { + log_info("Image size already matching, skipping operation."); + return 0; + } + } + + r = home_prepare_luks(h, already_activated, whole_disk, cache, setup, &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; + + log_info("offset = %" PRIu64 ", size = %" PRIu64 ", image = %" PRIu64, setup->partition_offset, setup->partition_size, old_image_size); + + if ((UINT64_MAX - setup->partition_offset) < setup->partition_size || + setup->partition_offset + setup->partition_size > old_image_size) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Old partition doesn't fit in backing storage, refusing."); + + if (S_ISREG(st.st_mode)) { + uint64_t partition_table_extra; + + partition_table_extra = old_image_size - setup->partition_size; + if (new_image_size <= partition_table_extra) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "New size smaller than partition table metadata."); + + new_partition_size = new_image_size - partition_table_extra; + } else { + assert(S_ISBLK(st.st_mode)); + + new_partition_size = DISK_SIZE_ROUND_DOWN(h->disk_size); + if (new_partition_size == setup->partition_size) { + log_info("Partition size already matching, skipping operation."); + return 0; + } + } + + if ((UINT64_MAX - setup->partition_offset) < new_partition_size || + setup->partition_offset + new_partition_size > new_image_size) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "New partition doesn't fit into backing storage, refusing."); + + crypto_offset = crypt_get_data_offset(setup->crypt_device); + if (setup->partition_size / 512U <= crypto_offset) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Weird, old crypto payload offset doesn't actually fit in partition size?"); + if (new_partition_size / 512U <= crypto_offset) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "New size smaller than crypto payload offset?"); + + old_fs_size = (setup->partition_size / 512U - crypto_offset) * 512U; + new_fs_size = (new_partition_size / 512U - crypto_offset) * 512U; + + /* Before we start doing anything, let's figure out if we actually can */ + resize_type = can_resize_fs(setup->root_fd, old_fs_size, new_fs_size); + if (resize_type < 0) + return resize_type; + if (resize_type == CAN_RESIZE_OFFLINE && already_activated) + return log_error_errno(SYNTHETIC_ERRNO(ETXTBSY), "File systems of this type can only be resized offline, but is currently online."); + + log_info("Ready to resize image size %s → %s, partition size %s → %s, file system size %s → %s.", + format_bytes(buffer1, sizeof(buffer1), old_image_size), + format_bytes(buffer2, sizeof(buffer2), new_image_size), + format_bytes(buffer3, sizeof(buffer3), setup->partition_size), + format_bytes(buffer4, sizeof(buffer4), new_partition_size), + format_bytes(buffer5, sizeof(buffer5), old_fs_size), + format_bytes(buffer6, sizeof(buffer6), new_fs_size)); + + r = prepare_resize_partition( + image_fd, + setup->partition_offset, + setup->partition_size, + new_partition_size, + &disk_uuid, + &table); + if (r < 0) + return r; + + if (new_fs_size > old_fs_size) { + + if (S_ISREG(st.st_mode)) { + /* Grow file size */ + r = home_truncate(h, image_fd, ip, new_image_size); + if (r < 0) + return r; + + log_info("Growing of image file completed."); + } + + /* Make sure loopback device sees the new bigger size */ + r = loop_device_refresh_size(setup->loop, UINT64_MAX, new_partition_size); + if (r == -ENOTTY) + log_debug_errno(r, "Device is not a loopback device, not refreshing size."); + else if (r < 0) + return log_error_errno(r, "Failed to refresh loopback device size: %m"); + else + log_info("Refreshing loop device size completed."); + + r = apply_resize_partition(image_fd, disk_uuid, table); + if (r < 0) + return r; + if (r > 0) + log_info("Growing of partition completed."); + + if (ioctl(image_fd, BLKRRPART, 0) < 0) + log_debug_errno(errno, "BLKRRPART failed on block device, ignoring: %m"); + + /* Tell LUKS about the new bigger size too */ + r = crypt_resize(setup->crypt_device, setup->dm_name, new_fs_size / 512U); + if (r < 0) + return log_error_errno(r, "Failed to grow LUKS device: %m"); + + log_info("LUKS device growing completed."); + } else { + r = home_store_embedded_identity(new_home, setup->root_fd, h->uid, embedded_home); + if (r < 0) + return r; + + if (S_ISREG(st.st_mode)) { + if (user_record_luks_discard(h)) + /* Before we shrink, let's trim the file system, so that we need less space on disk during the shrinking */ + (void) run_fitrim(setup->root_fd); + else { + /* If discard is off, let's ensure all backing blocks are allocated, so that our resize operation doesn't fail half-way */ + r = run_fallocate(image_fd, &st); + if (r < 0) + return r; + } + } + } + + /* Now resize the file system */ + if (resize_type == CAN_RESIZE_ONLINE) + r = resize_fs(setup->root_fd, new_fs_size, NULL); + else + r = ext4_offline_resize_fs(setup, new_fs_size, user_record_luks_discard(h), user_record_mount_flags(h)); + if (r < 0) + return log_error_errno(r, "Failed to resize file system: %m"); + + log_info("File system resizing completed."); + + /* Immediately sync afterwards */ + r = home_sync_and_statfs(setup->root_fd, NULL); + if (r < 0) + return r; + + if (new_fs_size < old_fs_size) { + + /* Shrink the LUKS device now, matching the new file system size */ + r = crypt_resize(setup->crypt_device, setup->dm_name, new_fs_size / 512); + if (r < 0) + return log_error_errno(r, "Failed to shrink LUKS device: %m"); + + log_info("LUKS device shrinking completed."); + + if (S_ISREG(st.st_mode)) { + /* Shrink the image file */ + if (ftruncate(image_fd, new_image_size) < 0) + return log_error_errno(errno, "Failed to shrink image file %s: %m", ip); + + log_info("Shrinking of image file completed."); + } + + /* Refresh the loop devices size */ + r = loop_device_refresh_size(setup->loop, UINT64_MAX, new_partition_size); + if (r == -ENOTTY) + log_debug_errno(r, "Device is not a loopback device, not refreshing size."); + else if (r < 0) + return log_error_errno(r, "Failed to refresh loopback device size: %m"); + else + log_info("Refreshing loop device size completed."); + + r = apply_resize_partition(image_fd, disk_uuid, table); + if (r < 0) + return r; + if (r > 0) + log_info("Shrinking of partition completed."); + + if (ioctl(image_fd, BLKRRPART, 0) < 0) + log_debug_errno(errno, "BLKRRPART failed on block device, ignoring: %m"); + } else { + r = home_store_embedded_identity(new_home, setup->root_fd, h->uid, embedded_home); + if (r < 0) + return r; + } + + r = home_store_header_identity_luks(new_home, setup, header_home); + if (r < 0) + return r; + + r = home_extend_embedded_identity(new_home, h, setup); + if (r < 0) + return r; + + if (user_record_luks_discard(h)) + (void) run_fitrim(setup->root_fd); + + r = home_sync_and_statfs(setup->root_fd, &sfs); + if (r < 0) + return r; + + r = home_setup_undo(setup); + if (r < 0) + return r; + + log_info("Everything completed."); + + print_size_summary(new_image_size, new_fs_size, &sfs); + + *ret_home = TAKE_PTR(new_home); + return 0; +} + +int home_passwd_luks( + UserRecord *h, + HomeSetup *setup, + PasswordCache *cache, /* the passwords acquired via PKCS#11/FIDO2 security tokens */ + char **effective_passwords /* new passwords */) { + + size_t volume_key_size, i, max_key_slots, n_effective; + _cleanup_(erase_and_freep) void *volume_key = NULL; + struct crypt_pbkdf_type good_pbkdf, minimal_pbkdf; + const char *type; + char **list; + int r; + + assert(h); + assert(user_record_storage(h) == USER_LUKS); + assert(setup); + + type = crypt_get_type(setup->crypt_device); + if (!type) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to determine crypto device type."); + + r = crypt_keyslot_max(type); + if (r <= 0) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to determine number of key slots."); + max_key_slots = r; + + r = crypt_get_volume_key_size(setup->crypt_device); + if (r <= 0) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to determine volume key size."); + volume_key_size = (size_t) r; + + volume_key = malloc(volume_key_size); + if (!volume_key) + return log_oom(); + + r = -ENOKEY; + FOREACH_POINTER(list, cache->pkcs11_passwords, cache->fido2_passwords, h->password) { + r = luks_try_passwords(setup->crypt_device, list, volume_key, &volume_key_size); + if (r != -ENOKEY) + break; + } + if (r == -ENOKEY) + return log_error_errno(SYNTHETIC_ERRNO(ENOKEY), "Failed to unlock LUKS superblock with supplied passwords."); + if (r < 0) + return log_error_errno(r, "Failed to unlocks LUKS superblock: %m"); + + n_effective = strv_length(effective_passwords); + + build_good_pbkdf(&good_pbkdf, h); + build_minimal_pbkdf(&minimal_pbkdf, h); + + for (i = 0; i < max_key_slots; i++) { + r = crypt_keyslot_destroy(setup->crypt_device, i); + if (r < 0 && !IN_SET(r, -ENOENT, -EINVAL)) /* Returns EINVAL or ENOENT if there's no key in this slot already */ + return log_error_errno(r, "Failed to destroy LUKS password: %m"); + + if (i >= n_effective) { + if (r >= 0) + log_info("Destroyed LUKS key slot %zu.", i); + continue; + } + + if (strv_contains(cache->pkcs11_passwords, effective_passwords[i]) || + strv_contains(cache->fido2_passwords, effective_passwords[i])) { + log_debug("Using minimal PBKDF for slot %zu", i); + r = crypt_set_pbkdf_type(setup->crypt_device, &minimal_pbkdf); + } else { + log_debug("Using good PBKDF for slot %zu", i); + r = crypt_set_pbkdf_type(setup->crypt_device, &good_pbkdf); + } + if (r < 0) + return log_error_errno(r, "Failed to tweak PBKDF for slot %zu: %m", i); + + r = crypt_keyslot_add_by_volume_key( + setup->crypt_device, + i, + volume_key, + volume_key_size, + effective_passwords[i], + strlen(effective_passwords[i])); + if (r < 0) + return log_error_errno(r, "Failed to set up LUKS password: %m"); + + log_info("Updated LUKS key slot %zu.", i); + } + + return 1; +} + +int home_lock_luks(UserRecord *h) { + _cleanup_(crypt_freep) struct crypt_device *cd = NULL; + _cleanup_free_ char *dm_name = NULL, *dm_node = NULL; + _cleanup_close_ int root_fd = -1; + const char *p; + int r; + + assert(h); + + assert_se(p = user_record_home_directory(h)); + root_fd = open(p, O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW); + if (root_fd < 0) + return log_error_errno(errno, "Failed to open home directory: %m"); + + r = make_dm_names(h->user_name, &dm_name, &dm_node); + if (r < 0) + return r; + + r = crypt_init_by_name(&cd, dm_name); + if (r < 0) + return log_error_errno(r, "Failed to initialize cryptsetup context for %s: %m", dm_name); + + log_info("Discovered used LUKS device %s.", dm_node); + cryptsetup_enable_logging(cd); + + if (syncfs(root_fd) < 0) /* Snake oil, but let's better be safe than sorry */ + return log_error_errno(errno, "Failed to synchronize file system %s: %m", p); + + root_fd = safe_close(root_fd); + + log_info("File system synchronized."); + + /* Note that we don't invoke FIFREEZE here, it appears libcryptsetup/device-mapper already does that on its own for us */ + + r = crypt_suspend(cd, dm_name); + if (r < 0) + return log_error_errno(r, "Failed to suspend cryptsetup device: %s: %m", dm_node); + + log_info("LUKS device suspended."); + return 0; +} + +static int luks_try_resume( + struct crypt_device *cd, + const char *dm_name, + char **password) { + + char **pp; + int r; + + assert(cd); + assert(dm_name); + + STRV_FOREACH(pp, password) { + r = crypt_resume_by_passphrase( + cd, + dm_name, + CRYPT_ANY_SLOT, + *pp, + strlen(*pp)); + if (r >= 0) { + log_info("Resumed LUKS device %s.", dm_name); + return 0; + } + + log_debug_errno(r, "Password %zu didn't work for resuming device: %m", (size_t) (pp - password)); + } + + return -ENOKEY; +} + +int home_unlock_luks(UserRecord *h, PasswordCache *cache) { + _cleanup_free_ char *dm_name = NULL, *dm_node = NULL; + _cleanup_(crypt_freep) struct crypt_device *cd = NULL; + char **list; + int r; + + assert(h); + + r = make_dm_names(h->user_name, &dm_name, &dm_node); + if (r < 0) + return r; + + r = crypt_init_by_name(&cd, dm_name); + if (r < 0) + return log_error_errno(r, "Failed to initialize cryptsetup context for %s: %m", dm_name); + + log_info("Discovered used LUKS device %s.", dm_node); + cryptsetup_enable_logging(cd); + + r = -ENOKEY; + FOREACH_POINTER(list, cache->pkcs11_passwords, cache->fido2_passwords, h->password) { + r = luks_try_resume(cd, dm_name, list); + if (r != -ENOKEY) + break; + } + if (r == -ENOKEY) + return log_error_errno(r, "No valid password for LUKS superblock."); + if (r < 0) + return log_error_errno(r, "Failed to resume LUKS superblock: %m"); + + log_info("LUKS device resumed."); + return 0; +} |