chiark / gitweb /
util: replace close_nointr_nofail() by a more useful safe_close()
[elogind.git] / src / journal / journal-authenticate.c
index 5a0314b..5ab1982 100644 (file)
 #include "journal-authenticate.h"
 #include "fsprg.h"
 
-static void *fsprg_state(JournalFile *f) {
-        uint64_t a, b;
-        assert(f);
-
-        if (!f->authenticate)
-                return NULL;
-
-        a = le64toh(f->fsprg_header->header_size);
-        b = le64toh(f->fsprg_header->state_size);
-
-        if (a + b > f->fsprg_size)
-                return NULL;
-
-        return (uint8_t*) f->fsprg_header + a;
-}
-
 static uint64_t journal_file_tag_seqnum(JournalFile *f) {
         uint64_t r;
 
@@ -61,14 +45,12 @@ int journal_file_append_tag(JournalFile *f) {
 
         assert(f);
 
-        if (!f->authenticate)
+        if (!f->seal)
                 return 0;
 
         if (!f->hmac_running)
                 return 0;
 
-        log_debug("Writing tag for epoch %llu\n", (unsigned long long) FSPRG_GetEpoch(fsprg_state(f)));
-
         assert(f->hmac);
 
         r = journal_file_append_object(f, OBJECT_TAG, sizeof(struct TagObject), &o, &p);
@@ -76,10 +58,15 @@ int journal_file_append_tag(JournalFile *f) {
                 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, p);
+        r = journal_file_hmac_put_object(f, OBJECT_TAG, o, p);
         if (r < 0)
                 return r;
 
@@ -90,12 +77,11 @@ int journal_file_append_tag(JournalFile *f) {
         return 0;
 }
 
-static int journal_file_hmac_start(JournalFile *f) {
+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->authenticate)
+        if (!f->seal)
                 return 0;
 
         if (f->hmac_running)
@@ -103,7 +89,7 @@ static int journal_file_hmac_start(JournalFile *f) {
 
         /* Prepare HMAC for next cycle */
         gcry_md_reset(f->hmac);
-        FSPRG_GetKey(fsprg_state(f), key, sizeof(key), 0);
+        FSPRG_GetKey(f->fsprg_state, key, sizeof(key), 0);
         gcry_md_setkey(f->hmac, key, sizeof(key));
 
         f->hmac_running = true;
@@ -116,57 +102,57 @@ static int journal_file_get_epoch(JournalFile *f, uint64_t realtime, uint64_t *e
 
         assert(f);
         assert(epoch);
-        assert(f->authenticate);
+        assert(f->seal);
 
-        if (le64toh(f->fsprg_header->fsprg_start_usec) == 0 ||
-            le64toh(f->fsprg_header->fsprg_interval_usec) == 0)
+        if (f->fss_start_usec == 0 ||
+            f->fss_interval_usec == 0)
                 return -ENOTSUP;
 
-        if (realtime < le64toh(f->fsprg_header->fsprg_start_usec))
+        if (realtime < f->fss_start_usec)
                 return -ESTALE;
 
-        t = realtime - le64toh(f->fsprg_header->fsprg_start_usec);
-        t = t / le64toh(f->fsprg_header->fsprg_interval_usec);
+        t = realtime - f->fss_start_usec;
+        t = t / f->fss_interval_usec;
 
         *epoch = t;
         return 0;
 }
 
-static int journal_file_need_evolve(JournalFile *f, uint64_t realtime) {
+static int journal_file_fsprg_need_evolve(JournalFile *f, uint64_t realtime) {
         uint64_t goal, epoch;
         int r;
         assert(f);
 
-        if (!f->authenticate)
+        if (!f->seal)
                 return 0;
 
         r = journal_file_get_epoch(f, realtime, &goal);
         if (r < 0)
                 return r;
 
-        epoch = FSPRG_GetEpoch(fsprg_state(f));
+        epoch = FSPRG_GetEpoch(f->fsprg_state);
         if (epoch > goal)
                 return -ESTALE;
 
         return epoch != goal;
 }
 
-static int journal_file_evolve(JournalFile *f, uint64_t realtime) {
+int journal_file_fsprg_evolve(JournalFile *f, uint64_t realtime) {
         uint64_t goal, epoch;
         int r;
 
         assert(f);
 
-        if (!f->authenticate)
+        if (!f->seal)
                 return 0;
 
         r = journal_file_get_epoch(f, realtime, &goal);
         if (r < 0)
                 return r;
 
-        epoch = FSPRG_GetEpoch(fsprg_state(f));
+        epoch = FSPRG_GetEpoch(f->fsprg_state);
         if (epoch < goal)
-                log_debug("Evolving FSPRG key from epoch %llu to %llu.", (unsigned long long) epoch, (unsigned long long) goal);
+                log_debug("Evolving FSPRG key from epoch %"PRIu64" to %"PRIu64".", epoch, goal);
 
         for (;;) {
                 if (epoch > goal)
@@ -174,20 +160,61 @@ static int journal_file_evolve(JournalFile *f, uint64_t realtime) {
                 if (epoch == goal)
                         return 0;
 
-                FSPRG_Evolve(fsprg_state(f));
-                epoch = FSPRG_GetEpoch(fsprg_state(f));
+                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->authenticate)
+        if (!f->seal)
                 return 0;
 
-        r = journal_file_need_evolve(f, realtime);
+        if (realtime <= 0)
+                realtime = now(CLOCK_REALTIME);
+
+        r = journal_file_fsprg_need_evolve(f, realtime);
         if (r <= 0)
                 return 0;
 
@@ -195,44 +222,50 @@ int journal_file_maybe_append_tag(JournalFile *f, uint64_t realtime) {
         if (r < 0)
                 return r;
 
-        r = journal_file_evolve(f, realtime);
-        if (r < 0)
-                return r;
-
-        r = journal_file_hmac_start(f);
+        r = journal_file_fsprg_evolve(f, realtime);
         if (r < 0)
                 return r;
 
         return 0;
 }
 
-int journal_file_hmac_put_object(JournalFile *f, int type, uint64_t p) {
+int journal_file_hmac_put_object(JournalFile *f, int type, Object *o, uint64_t p) {
         int r;
-        Object *o;
 
         assert(f);
 
-        if (!f->authenticate)
+        if (!f->seal)
                 return 0;
 
         r = journal_file_hmac_start(f);
         if (r < 0)
                 return r;
 
-        r = journal_file_move_to_object(f, type, p, &o);
-        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 >= 0 && 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 */
+                /* 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));
@@ -247,6 +280,7 @@ int journal_file_hmac_put_object(JournalFile *f, int type, uint64_t p) {
         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;
@@ -260,7 +294,7 @@ int journal_file_hmac_put_header(JournalFile *f) {
 
         assert(f);
 
-        if (!f->authenticate)
+        if (!f->seal)
                 return 0;
 
         r = journal_file_hmac_start(f);
@@ -268,42 +302,45 @@ int journal_file_hmac_put_header(JournalFile *f) {
                 return r;
 
         /* All but state+reserved, boot_id, arena_size,
-         * tail_object_offset, n_objects, n_entries, tail_seqnum,
+         * 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, header_tag */
+         * 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));
-        gcry_md_write(f->hmac, &f->header->head_entry_seqnum, offsetof(Header, head_entry_realtime) - offsetof(Header, head_entry_seqnum));
 
         return 0;
 }
 
-int journal_file_load_fsprg(JournalFile *f) {
+int journal_file_fss_load(JournalFile *f) {
         int r, fd = -1;
         char *p = NULL;
         struct stat st;
-        FSPRGHeader *m = NULL;
+        FSSHeader *m = NULL;
         sd_id128_t machine;
 
         assert(f);
 
-        if (!f->authenticate)
+        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 "/fsprg",
+        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) {
-                log_error("Failed to open %s: %m", p);
+                if (errno != ENOENT)
+                        log_error("Failed to open %s: %m", p);
+
                 r = -errno;
                 goto finish;
         }
@@ -313,19 +350,19 @@ int journal_file_load_fsprg(JournalFile *f) {
                 goto finish;
         }
 
-        if (st.st_size < (off_t) sizeof(FSPRGHeader)) {
+        if (st.st_size < (off_t) sizeof(FSSHeader)) {
                 r = -ENODATA;
                 goto finish;
         }
 
-        m = mmap(NULL, PAGE_ALIGN(sizeof(FSPRGHeader)), PROT_READ, MAP_SHARED, fd, 0);
+        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, FSPRG_HEADER_SIGNATURE, 8) != 0) {
+        if (memcmp(m->signature, FSS_HEADER_SIGNATURE, 8) != 0) {
                 r = -EBADMSG;
                 goto finish;
         }
@@ -335,18 +372,18 @@ int journal_file_load_fsprg(JournalFile *f) {
                 goto finish;
         }
 
-        if (le64toh(m->header_size) < sizeof(FSPRGHeader)) {
+        if (le64toh(m->header_size) < sizeof(FSSHeader)) {
                 r = -EBADMSG;
                 goto finish;
         }
 
-        if (le64toh(m->state_size) != FSPRG_stateinbytes(m->secpar)) {
+        if (le64toh(m->fsprg_state_size) != FSPRG_stateinbytes(le16toh(m->fsprg_secpar))) {
                 r = -EBADMSG;
                 goto finish;
         }
 
-        f->fsprg_size = le64toh(m->header_size) + le64toh(m->state_size);
-        if ((uint64_t) st.st_size < f->fsprg_size) {
+        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;
         }
@@ -356,38 +393,57 @@ int journal_file_load_fsprg(JournalFile *f) {
                 goto finish;
         }
 
-        if (le64toh(m->fsprg_start_usec) <= 0 ||
-            le64toh(m->fsprg_interval_usec) <= 0) {
+        if (le64toh(m->start_usec) <= 0 ||
+            le64toh(m->interval_usec) <= 0) {
                 r = -EBADMSG;
                 goto finish;
         }
 
-        f->fsprg_header = mmap(NULL, PAGE_ALIGN(f->fsprg_size), PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
-        if (f->fsprg_header == MAP_FAILED) {
-                f->fsprg_header = NULL;
+        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(FSPRGHeader)));
-
-        if (fd >= 0)
-                close_nointr_nofail(fd);
+                munmap(m, PAGE_ALIGN(sizeof(FSSHeader)));
 
+        safe_close(fd);
         free(p);
+
         return r;
 }
 
-int journal_file_setup_hmac(JournalFile *f) {
+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->authenticate)
+        if (!f->seal)
                 return 0;
 
+        initialize_libgcrypt();
+
         e = gcry_md_open(&f->hmac, GCRY_MD_SHA256, GCRY_MD_FLAG_HMAC);
         if (e != 0)
                 return -ENOTSUP;
@@ -399,7 +455,7 @@ int journal_file_append_first_tag(JournalFile *f) {
         int r;
         uint64_t p;
 
-        if (!f->authenticate)
+        if (!f->seal)
                 return 0;
 
         log_debug("Calculating first tag...");
@@ -413,7 +469,7 @@ int journal_file_append_first_tag(JournalFile *f) {
                 return -EINVAL;
         p -= offsetof(Object, hash_table.items);
 
-        r = journal_file_hmac_put_object(f, OBJECT_FIELD_HASH_TABLE, p);
+        r = journal_file_hmac_put_object(f, OBJECT_FIELD_HASH_TABLE, NULL, p);
         if (r < 0)
                 return r;
 
@@ -422,7 +478,7 @@ int journal_file_append_first_tag(JournalFile *f) {
                 return -EINVAL;
         p -= offsetof(Object, hash_table.items);
 
-        r = journal_file_hmac_put_object(f, OBJECT_DATA_HASH_TABLE, p);
+        r = journal_file_hmac_put_object(f, OBJECT_DATA_HASH_TABLE, NULL, p);
         if (r < 0)
                 return r;
 
@@ -433,8 +489,74 @@ int journal_file_append_first_tag(JournalFile *f) {
         return 0;
 }
 
-bool journal_file_fsprg_enabled(JournalFile *f) {
+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 !!(le32toh(f->header->compatible_flags) & HEADER_COMPATIBLE_AUTHENTICATED);
+        return true;
 }