/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include "chattr-util.h" #include "errno-util.h" #include "fd-util.h" #include "fs-util.h" #include "fsprg.h" #include "hostname-util.h" #include "io-util.h" #include "journal-authenticate.h" #include "journalctl.h" #include "journalctl-authenticate.h" #include "memstream-util.h" #include "path-util.h" #include "qrcode-util.h" #include "random-util.h" #include "stat-util.h" #include "terminal-util.h" #include "tmpfile-util.h" static int format_key( const void *seed, size_t seed_size, uint64_t start, uint64_t interval, char **ret) { _cleanup_(memstream_done) MemStream m = {}; FILE *f; assert(seed); assert(seed_size > 0); assert(ret); f = memstream_init(&m); if (!f) return -ENOMEM; for (size_t i = 0; i < seed_size; i++) { if (i > 0 && i % 3 == 0) fputc('-', f); fprintf(f, "%02x", ((uint8_t*) seed)[i]); } fprintf(f, "/%"PRIx64"-%"PRIx64, start, interval); return memstream_finalize(&m, ret, NULL); } int action_setup_keys(void) { _cleanup_(unlink_and_freep) char *tmpfile = NULL; _cleanup_close_ int fd = -EBADF; _cleanup_free_ char *path = NULL; size_t mpk_size, seed_size, state_size; uint8_t *mpk, *seed, *state; sd_id128_t machine, boot; uint64_t n; int r; assert(arg_action == ACTION_SETUP_KEYS); r = is_dir("/var/log/journal/", /* follow = */ false); if (r == 0) return log_error_errno(SYNTHETIC_ERRNO(ENOTDIR), "/var/log/journal is not a directory, must be using persistent logging for FSS."); if (r == -ENOENT) return log_error_errno(r, "Directory /var/log/journal/ does not exist, must be using persistent logging for FSS."); if (r < 0) return log_error_errno(r, "Failed to check if /var/log/journal/ is a directory: %m"); r = sd_id128_get_machine(&machine); if (r < 0) return log_error_errno(r, "Failed to get machine ID: %m"); r = sd_id128_get_boot(&boot); if (r < 0) return log_error_errno(r, "Failed to get boot ID: %m"); path = path_join("/var/log/journal/", SD_ID128_TO_STRING(machine), "/fss"); if (!path) return log_oom(); if (arg_force) { if (unlink(path) < 0 && errno != ENOENT) return log_error_errno(errno, "Failed to remove \"%s\": %m", path); } else if (access(path, F_OK) >= 0) return log_error_errno(SYNTHETIC_ERRNO(EEXIST), "Sealing key file %s exists already. Use --force to recreate.", path); mpk_size = FSPRG_mskinbytes(FSPRG_RECOMMENDED_SECPAR); mpk = alloca_safe(mpk_size); seed_size = FSPRG_RECOMMENDED_SEEDLEN; seed = alloca_safe(seed_size); state_size = FSPRG_stateinbytes(FSPRG_RECOMMENDED_SECPAR); state = alloca_safe(state_size); log_info("Generating seed..."); r = crypto_random_bytes(seed, seed_size); if (r < 0) return log_error_errno(r, "Failed to acquire random seed: %m"); log_info("Generating key pair..."); r = FSPRG_GenMK(NULL, mpk, seed, seed_size, FSPRG_RECOMMENDED_SECPAR); if (r < 0) return log_error_errno(r, "Failed to generate key pair: %m"); log_info("Generating sealing key..."); r = FSPRG_GenState0(state, mpk, seed, seed_size); if (r < 0) return log_error_errno(r, "Failed to generate sealing key: %m"); assert(arg_interval > 0); n = now(CLOCK_REALTIME); n /= arg_interval; fd = open_tmpfile_linkable(path, O_WRONLY|O_CLOEXEC, &tmpfile); if (fd < 0) return log_error_errno(fd, "Failed to open a temporary file for %s: %m", path); r = chattr_secret(fd, CHATTR_WARN_UNSUPPORTED_FLAGS); if (r < 0) log_full_errno(ERRNO_IS_NOT_SUPPORTED(r) ? LOG_DEBUG : LOG_WARNING, r, "Failed to set file attributes on a temporary file for '%s', ignoring: %m", path); struct FSSHeader h = { .signature = { 'K', 'S', 'H', 'H', 'R', 'H', 'L', 'P' }, .machine_id = machine, .boot_id = boot, .header_size = htole64(sizeof(h)), .start_usec = htole64(n * arg_interval), .interval_usec = htole64(arg_interval), .fsprg_secpar = htole16(FSPRG_RECOMMENDED_SECPAR), .fsprg_state_size = htole64(state_size), }; r = loop_write(fd, &h, sizeof(h)); if (r < 0) return log_error_errno(r, "Failed to write header: %m"); r = loop_write(fd, state, state_size); if (r < 0) return log_error_errno(r, "Failed to write state: %m"); r = link_tmpfile(fd, tmpfile, path, /* flags = */ 0); if (r < 0) return log_error_errno(r, "Failed to link file: %m"); tmpfile = mfree(tmpfile); _cleanup_free_ char *key = NULL; r = format_key(seed, seed_size, n, arg_interval, &key); if (r < 0) return r; if (!on_tty()) { /* If we are not on a TTY, show only the key. */ puts(key); return 0; } _cleanup_free_ char *hn = NULL; hn = gethostname_malloc(); if (hn) hostname_cleanup(hn); fprintf(stderr, "\nNew keys have been generated for host %s%s" SD_ID128_FORMAT_STR ".\n" "\n" "The %ssecret sealing key%s has been written to the following local file.\n" "This key file is automatically updated when the sealing key is advanced.\n" "It should not be used on multiple hosts.\n" "\n" "\t%s\n" "\n" "The sealing key is automatically changed every %s.\n" "\n" "Please write down the following %ssecret verification key%s. It should be stored\n" "in a safe location and should not be saved locally on disk.\n" "\n\t%s", strempty(hn), hn ? "/" : "", SD_ID128_FORMAT_VAL(machine), ansi_highlight(), ansi_normal(), path, FORMAT_TIMESPAN(arg_interval, 0), ansi_highlight(), ansi_normal(), ansi_highlight_red()); fflush(stderr); puts(key); fputs(ansi_normal(), stderr); #if HAVE_QRENCODE _cleanup_free_ char *url = NULL; url = strjoin("fss://", key, "?machine=", SD_ID128_TO_STRING(machine), hn ? ";hostname=" : "", hn); if (!url) return log_oom(); (void) print_qrcode(stderr, "To transfer the verification key to your phone scan the QR code below", url); #endif return 0; }