+++ /dev/null
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
-/***
- This file is part of systemd.
-
- Copyright 2012 Lennart Poettering
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
-
-#include <fcntl.h>
-#include <sys/mman.h>
-
-#include "journal-def.h"
-#include "journal-file.h"
-#include "journal-authenticate.h"
-#include "fsprg.h"
-
-static uint64_t journal_file_tag_seqnum(JournalFile *f) {
- uint64_t r;
-
- assert(f);
-
- r = le64toh(f->header->n_tags) + 1;
- f->header->n_tags = htole64(r);
-
- return r;
-}
-
-int journal_file_append_tag(JournalFile *f) {
- Object *o;
- uint64_t p;
- int r;
-
- assert(f);
-
- if (!f->seal)
- return 0;
-
- if (!f->hmac_running)
- return 0;
-
- assert(f->hmac);
-
- r = journal_file_append_object(f, OBJECT_TAG, sizeof(struct TagObject), &o, &p);
- if (r < 0)
- return r;
-
- o->tag.seqnum = htole64(journal_file_tag_seqnum(f));
- o->tag.epoch = htole64(FSPRG_GetEpoch(f->fsprg_state));
-
- log_debug("Writing tag %"PRIu64" for epoch %"PRIu64"",
- le64toh(o->tag.seqnum),
- FSPRG_GetEpoch(f->fsprg_state));
-
- /* Add the tag object itself, so that we can protect its
- * header. This will exclude the actual hash value in it */
- r = journal_file_hmac_put_object(f, OBJECT_TAG, o, p);
- if (r < 0)
- return r;
-
- /* Get the HMAC tag and store it in the object */
- memcpy(o->tag.tag, gcry_md_read(f->hmac, 0), TAG_LENGTH);
- f->hmac_running = false;
-
- return 0;
-}
-
-int journal_file_hmac_start(JournalFile *f) {
- uint8_t key[256 / 8]; /* Let's pass 256 bit from FSPRG to HMAC */
- assert(f);
-
- if (!f->seal)
- return 0;
-
- if (f->hmac_running)
- return 0;
-
- /* Prepare HMAC for next cycle */
- gcry_md_reset(f->hmac);
- FSPRG_GetKey(f->fsprg_state, key, sizeof(key), 0);
- gcry_md_setkey(f->hmac, key, sizeof(key));
-
- f->hmac_running = true;
-
- return 0;
-}
-
-static int journal_file_get_epoch(JournalFile *f, uint64_t realtime, uint64_t *epoch) {
- uint64_t t;
-
- assert(f);
- assert(epoch);
- assert(f->seal);
-
- if (f->fss_start_usec == 0 ||
- f->fss_interval_usec == 0)
- return -EOPNOTSUPP;
-
- if (realtime < f->fss_start_usec)
- return -ESTALE;
-
- t = realtime - f->fss_start_usec;
- t = t / f->fss_interval_usec;
-
- *epoch = t;
- return 0;
-}
-
-static int journal_file_fsprg_need_evolve(JournalFile *f, uint64_t realtime) {
- uint64_t goal, epoch;
- int r;
- assert(f);
-
- if (!f->seal)
- return 0;
-
- r = journal_file_get_epoch(f, realtime, &goal);
- if (r < 0)
- return r;
-
- epoch = FSPRG_GetEpoch(f->fsprg_state);
- if (epoch > goal)
- return -ESTALE;
-
- return epoch != goal;
-}
-
-int journal_file_fsprg_evolve(JournalFile *f, uint64_t realtime) {
- uint64_t goal, epoch;
- int r;
-
- assert(f);
-
- if (!f->seal)
- return 0;
-
- r = journal_file_get_epoch(f, realtime, &goal);
- if (r < 0)
- return r;
-
- epoch = FSPRG_GetEpoch(f->fsprg_state);
- if (epoch < goal)
- log_debug("Evolving FSPRG key from epoch %"PRIu64" to %"PRIu64".", epoch, goal);
-
- for (;;) {
- if (epoch > goal)
- return -ESTALE;
- if (epoch == goal)
- return 0;
-
- FSPRG_Evolve(f->fsprg_state);
- epoch = FSPRG_GetEpoch(f->fsprg_state);
- }
-}
-
-int journal_file_fsprg_seek(JournalFile *f, uint64_t goal) {
- void *msk;
- uint64_t epoch;
-
- assert(f);
-
- if (!f->seal)
- return 0;
-
- assert(f->fsprg_seed);
-
- if (f->fsprg_state) {
- /* Cheaper... */
-
- epoch = FSPRG_GetEpoch(f->fsprg_state);
- if (goal == epoch)
- return 0;
-
- if (goal == epoch+1) {
- FSPRG_Evolve(f->fsprg_state);
- return 0;
- }
- } else {
- f->fsprg_state_size = FSPRG_stateinbytes(FSPRG_RECOMMENDED_SECPAR);
- f->fsprg_state = malloc(f->fsprg_state_size);
-
- if (!f->fsprg_state)
- return -ENOMEM;
- }
-
- log_debug("Seeking FSPRG key to %"PRIu64".", goal);
-
- msk = alloca(FSPRG_mskinbytes(FSPRG_RECOMMENDED_SECPAR));
- FSPRG_GenMK(msk, NULL, f->fsprg_seed, f->fsprg_seed_size, FSPRG_RECOMMENDED_SECPAR);
- FSPRG_Seek(f->fsprg_state, goal, msk, f->fsprg_seed, f->fsprg_seed_size);
- return 0;
-}
-
-int journal_file_maybe_append_tag(JournalFile *f, uint64_t realtime) {
- int r;
-
- assert(f);
-
- if (!f->seal)
- return 0;
-
- if (realtime <= 0)
- realtime = now(CLOCK_REALTIME);
-
- r = journal_file_fsprg_need_evolve(f, realtime);
- if (r <= 0)
- return 0;
-
- r = journal_file_append_tag(f);
- if (r < 0)
- return r;
-
- r = journal_file_fsprg_evolve(f, realtime);
- if (r < 0)
- return r;
-
- return 0;
-}
-
-int journal_file_hmac_put_object(JournalFile *f, ObjectType type, Object *o, uint64_t p) {
- int r;
-
- assert(f);
-
- if (!f->seal)
- return 0;
-
- r = journal_file_hmac_start(f);
- if (r < 0)
- return r;
-
- if (!o) {
- r = journal_file_move_to_object(f, type, p, &o);
- if (r < 0)
- return r;
- } else {
- if (type > OBJECT_UNUSED && o->object.type != type)
- return -EBADMSG;
- }
-
- gcry_md_write(f->hmac, o, offsetof(ObjectHeader, payload));
-
- switch (o->object.type) {
-
- case OBJECT_DATA:
- /* All but hash and payload are mutable */
- gcry_md_write(f->hmac, &o->data.hash, sizeof(o->data.hash));
- gcry_md_write(f->hmac, o->data.payload, le64toh(o->object.size) - offsetof(DataObject, payload));
- break;
-
- case OBJECT_FIELD:
- /* Same here */
- gcry_md_write(f->hmac, &o->field.hash, sizeof(o->field.hash));
- gcry_md_write(f->hmac, o->field.payload, le64toh(o->object.size) - offsetof(FieldObject, payload));
- break;
-
- case OBJECT_ENTRY:
- /* All */
- gcry_md_write(f->hmac, &o->entry.seqnum, le64toh(o->object.size) - offsetof(EntryObject, seqnum));
- break;
-
- case OBJECT_FIELD_HASH_TABLE:
- case OBJECT_DATA_HASH_TABLE:
- case OBJECT_ENTRY_ARRAY:
- /* Nothing: everything is mutable */
- break;
-
- case OBJECT_TAG:
- /* All but the tag itself */
- gcry_md_write(f->hmac, &o->tag.seqnum, sizeof(o->tag.seqnum));
- gcry_md_write(f->hmac, &o->tag.epoch, sizeof(o->tag.epoch));
- break;
- default:
- return -EINVAL;
- }
-
- return 0;
-}
-
-int journal_file_hmac_put_header(JournalFile *f) {
- int r;
-
- assert(f);
-
- if (!f->seal)
- return 0;
-
- r = journal_file_hmac_start(f);
- if (r < 0)
- return r;
-
- /* All but state+reserved, boot_id, arena_size,
- * tail_object_offset, n_objects, n_entries,
- * tail_entry_seqnum, head_entry_seqnum, entry_array_offset,
- * head_entry_realtime, tail_entry_realtime,
- * tail_entry_monotonic, n_data, n_fields, n_tags,
- * n_entry_arrays. */
-
- gcry_md_write(f->hmac, f->header->signature, offsetof(Header, state) - offsetof(Header, signature));
- gcry_md_write(f->hmac, &f->header->file_id, offsetof(Header, boot_id) - offsetof(Header, file_id));
- gcry_md_write(f->hmac, &f->header->seqnum_id, offsetof(Header, arena_size) - offsetof(Header, seqnum_id));
- gcry_md_write(f->hmac, &f->header->data_hash_table_offset, offsetof(Header, tail_object_offset) - offsetof(Header, data_hash_table_offset));
-
- return 0;
-}
-
-int journal_file_fss_load(JournalFile *f) {
- int r, fd = -1;
- char *p = NULL;
- struct stat st;
- FSSHeader *m = NULL;
- sd_id128_t machine;
-
- assert(f);
-
- if (!f->seal)
- return 0;
-
- r = sd_id128_get_machine(&machine);
- if (r < 0)
- return r;
-
- if (asprintf(&p, "/var/log/journal/" SD_ID128_FORMAT_STR "/fss",
- SD_ID128_FORMAT_VAL(machine)) < 0)
- return -ENOMEM;
-
- fd = open(p, O_RDWR|O_CLOEXEC|O_NOCTTY, 0600);
- if (fd < 0) {
- if (errno != ENOENT)
- log_error_errno(errno, "Failed to open %s: %m", p);
-
- r = -errno;
- goto finish;
- }
-
- if (fstat(fd, &st) < 0) {
- r = -errno;
- goto finish;
- }
-
- if (st.st_size < (off_t) sizeof(FSSHeader)) {
- r = -ENODATA;
- goto finish;
- }
-
- m = mmap(NULL, PAGE_ALIGN(sizeof(FSSHeader)), PROT_READ, MAP_SHARED, fd, 0);
- if (m == MAP_FAILED) {
- m = NULL;
- r = -errno;
- goto finish;
- }
-
- if (memcmp(m->signature, FSS_HEADER_SIGNATURE, 8) != 0) {
- r = -EBADMSG;
- goto finish;
- }
-
- if (m->incompatible_flags != 0) {
- r = -EPROTONOSUPPORT;
- goto finish;
- }
-
- if (le64toh(m->header_size) < sizeof(FSSHeader)) {
- r = -EBADMSG;
- goto finish;
- }
-
- if (le64toh(m->fsprg_state_size) != FSPRG_stateinbytes(le16toh(m->fsprg_secpar))) {
- r = -EBADMSG;
- goto finish;
- }
-
- f->fss_file_size = le64toh(m->header_size) + le64toh(m->fsprg_state_size);
- if ((uint64_t) st.st_size < f->fss_file_size) {
- r = -ENODATA;
- goto finish;
- }
-
- if (!sd_id128_equal(machine, m->machine_id)) {
- r = -EHOSTDOWN;
- goto finish;
- }
-
- if (le64toh(m->start_usec) <= 0 ||
- le64toh(m->interval_usec) <= 0) {
- r = -EBADMSG;
- goto finish;
- }
-
- f->fss_file = mmap(NULL, PAGE_ALIGN(f->fss_file_size), PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
- if (f->fss_file == MAP_FAILED) {
- f->fss_file = NULL;
- r = -errno;
- goto finish;
- }
-
- f->fss_start_usec = le64toh(f->fss_file->start_usec);
- f->fss_interval_usec = le64toh(f->fss_file->interval_usec);
-
- f->fsprg_state = (uint8_t*) f->fss_file + le64toh(f->fss_file->header_size);
- f->fsprg_state_size = le64toh(f->fss_file->fsprg_state_size);
-
- r = 0;
-
-finish:
- if (m)
- munmap(m, PAGE_ALIGN(sizeof(FSSHeader)));
-
- safe_close(fd);
- free(p);
-
- return r;
-}
-
-static void initialize_libgcrypt(void) {
- const char *p;
-
- if (gcry_control(GCRYCTL_INITIALIZATION_FINISHED_P))
- return;
-
- p = gcry_check_version("1.4.5");
- assert(p);
-
- gcry_control(GCRYCTL_INITIALIZATION_FINISHED, 0);
-}
-
-int journal_file_hmac_setup(JournalFile *f) {
- gcry_error_t e;
-
- if (!f->seal)
- return 0;
-
- initialize_libgcrypt();
-
- e = gcry_md_open(&f->hmac, GCRY_MD_SHA256, GCRY_MD_FLAG_HMAC);
- if (e != 0)
- return -EOPNOTSUPP;
-
- return 0;
-}
-
-int journal_file_append_first_tag(JournalFile *f) {
- int r;
- uint64_t p;
-
- if (!f->seal)
- return 0;
-
- log_debug("Calculating first tag...");
-
- r = journal_file_hmac_put_header(f);
- if (r < 0)
- return r;
-
- p = le64toh(f->header->field_hash_table_offset);
- if (p < offsetof(Object, hash_table.items))
- return -EINVAL;
- p -= offsetof(Object, hash_table.items);
-
- r = journal_file_hmac_put_object(f, OBJECT_FIELD_HASH_TABLE, NULL, p);
- if (r < 0)
- return r;
-
- p = le64toh(f->header->data_hash_table_offset);
- if (p < offsetof(Object, hash_table.items))
- return -EINVAL;
- p -= offsetof(Object, hash_table.items);
-
- r = journal_file_hmac_put_object(f, OBJECT_DATA_HASH_TABLE, NULL, p);
- if (r < 0)
- return r;
-
- r = journal_file_append_tag(f);
- if (r < 0)
- return r;
-
- return 0;
-}
-
-int journal_file_parse_verification_key(JournalFile *f, const char *key) {
- uint8_t *seed;
- size_t seed_size, c;
- const char *k;
- int r;
- unsigned long long start, interval;
-
- seed_size = FSPRG_RECOMMENDED_SEEDLEN;
- seed = malloc(seed_size);
- if (!seed)
- return -ENOMEM;
-
- k = key;
- for (c = 0; c < seed_size; c++) {
- int x, y;
-
- while (*k == '-')
- k++;
-
- x = unhexchar(*k);
- if (x < 0) {
- free(seed);
- return -EINVAL;
- }
- k++;
- y = unhexchar(*k);
- if (y < 0) {
- free(seed);
- return -EINVAL;
- }
- k++;
-
- seed[c] = (uint8_t) (x * 16 + y);
- }
-
- if (*k != '/') {
- free(seed);
- return -EINVAL;
- }
- k++;
-
- r = sscanf(k, "%llx-%llx", &start, &interval);
- if (r != 2) {
- free(seed);
- return -EINVAL;
- }
-
- f->fsprg_seed = seed;
- f->fsprg_seed_size = seed_size;
-
- f->fss_start_usec = start * interval;
- f->fss_interval_usec = interval;
-
- return 0;
-}
-
-bool journal_file_next_evolve_usec(JournalFile *f, usec_t *u) {
- uint64_t epoch;
-
- assert(f);
- assert(u);
-
- if (!f->seal)
- return false;
-
- epoch = FSPRG_GetEpoch(f->fsprg_state);
-
- *u = (usec_t) (f->fss_start_usec + f->fss_interval_usec * epoch + f->fss_interval_usec);
-
- return true;
-}
~ianmdlvl / elogind.git / blobdiff