journal: don't write tag objects if nothing has been written since the last time

[elogind.git] / src / journal / journal-verify.c

diff --git a/src/journal/journal-verify.c b/src/journal/journal-verify.c
index 94f90b670d8101f1b90d21f034beb80ddb624505..9907c5fe26617c89fd87551f096c08ac9fa25408 100644 (file)
--- a/src/journal/journal-verify.c
+++ b/src/journal/journal-verify.c
@@ -35,7 +35,11 @@
 
 /* FIXME:
  *
- * - verify FSPRG
+ * - write bit mucking test
+ * - tag timestamps should be between entry timestamps
+ * - output validated time ranges
+ * - add missing fields to journal header dump
+ *
  * - Allow building without libgcrypt
  * - check with sparse
  * - 64bit conversions
@@ -592,7 +596,7 @@ static int verify_entry_array(
         return 0;
 }
 
-static int journal_file_parse_seed(JournalFile *f, const char *s) {
+static int journal_file_parse_verification_key(JournalFile *f, const char *key) {
         uint8_t *seed;
         size_t seed_size, c;
         const char *k;
@@ -604,7 +608,7 @@ static int journal_file_parse_seed(JournalFile *f, const char *s) {
         if (!seed)
                 return -ENOMEM;
 
-        k = s;
+        k = key;
         for (c = 0; c < seed_size; c++) {
                 int x, y;
 
@@ -641,20 +645,21 @@ static int journal_file_parse_seed(JournalFile *f, const char *s) {
 
         f->fsprg_seed = seed;
         f->fsprg_seed_size = seed_size;
-        f->fsprg_start_usec = start;
-        f->fsprg_interval_usec = interval;
+
+        f->fss_start_usec = start;
+        f->fss_interval_usec = interval;
 
         return 0;
 }
 
-int journal_file_verify(JournalFile *f, const char *seed) {
+int journal_file_verify(JournalFile *f, const char *key) {
         int r;
         Object *o;
-        uint64_t p = 0, last_tag = 0;
-        uint64_t n_tags = 0, entry_seqnum = 0, entry_monotonic = 0, entry_realtime = 0;
+        uint64_t p = 0, last_tag = 0, last_epoch = 0;
+        uint64_t entry_seqnum = 0, entry_monotonic = 0, entry_realtime = 0;
         sd_id128_t entry_boot_id;
         bool entry_seqnum_set = false, entry_monotonic_set = false, entry_realtime_set = false, found_main_entry_array = false;
-        uint64_t n_weird = 0, n_objects = 0, n_entries = 0, n_data = 0, n_fields = 0, n_data_hash_tables = 0, n_field_hash_tables = 0, n_entry_arrays = 0;
+        uint64_t n_weird = 0, n_objects = 0, n_entries = 0, n_data = 0, n_fields = 0, n_data_hash_tables = 0, n_field_hash_tables = 0, n_entry_arrays = 0, n_tags = 0;
         usec_t last_usec = 0;
         int data_fd = -1, entry_fd = -1, entry_array_fd = -1;
         char data_path[] = "/var/tmp/journal-data-XXXXXX",
@@ -663,8 +668,8 @@ int journal_file_verify(JournalFile *f, const char *seed) {
 
         assert(f);
 
-        if (seed) {
-                r = journal_file_parse_seed(f, seed);
+        if (key) {
+                r = journal_file_parse_verification_key(f, key);
                 if (r < 0) {
                         log_error("Failed to parse seed.");
                         return r;
@@ -842,21 +847,78 @@ int journal_file_verify(JournalFile *f, const char *seed) {
                         n_entry_arrays++;
                         break;
 
-                case OBJECT_TAG:
-                        if (!(le32toh(f->header->compatible_flags) & HEADER_COMPATIBLE_AUTHENTICATED)) {
-                                log_error("Tag object without authentication at %llu", (unsigned long long) p);
+                case OBJECT_TAG: {
+                        uint64_t q;
+
+                        if (!(le32toh(f->header->compatible_flags) & HEADER_COMPATIBLE_SEALED)) {
+                                log_error("Tag object without sealing at %llu", (unsigned long long) p);
                                 r = -EBADMSG;
                                 goto fail;
                         }
 
+                        log_debug("Checking tag %llu..", (unsigned long long) le64toh(o->tag.seqnum));
+
                         if (le64toh(o->tag.seqnum) != n_tags + 1) {
                                 log_error("Tag sequence number out of synchronization at %llu", (unsigned long long) p);
                                 r = -EBADMSG;
                                 goto fail;
                         }
 
+                        if (le64toh(o->tag.epoch) < last_epoch) {
+                                log_error("Epoch sequence out of synchronization at %llu", (unsigned long long) p);
+                                r = -EBADMSG;
+                                goto fail;
+                        }
+
+                        /* OK, now we know the epoch. So let's now set
+                         * it, and calculate the HMAC for everything
+                         * since the last tag. */
+                        r = journal_file_fsprg_seek(f, le64toh(o->tag.epoch));
+                        if (r < 0)
+                                goto fail;
+
+                        r = journal_file_hmac_start(f);
+                        if (r < 0)
+                                goto fail;
+
+                        if (last_tag == 0) {
+                                r = journal_file_hmac_put_header(f);
+                                if (r < 0)
+                                        goto fail;
+
+                                q = le64toh(f->header->header_size);
+                        } else
+                                q = last_tag;
+
+                        while (q <= p) {
+                                r = journal_file_move_to_object(f, -1, q, &o);
+                                if (r < 0)
+                                        goto fail;
+
+                                r = journal_file_hmac_put_object(f, -1, q);
+                                if (r < 0)
+                                        goto fail;
+
+                                q = q + ALIGN64(le64toh(o->object.size));
+                        }
+
+                        /* Position might have changed, let's reposition things */
+                        r = journal_file_move_to_object(f, -1, p, &o);
+                        if (r < 0)
+                                goto fail;
+
+                        if (memcmp(o->tag.tag, gcry_md_read(f->hmac, 0), TAG_LENGTH) != 0) {
+                                log_error("Tag failed verification at %llu", (unsigned long long) p);
+                                r = -EBADMSG;
+                                goto fail;
+                        }
+
+                        f->hmac_running = false;
+
+                        last_tag = p + ALIGN64(le64toh(o->object.size));
                         n_tags ++;
                         break;
+                }
 
                 default:
                         n_weird ++;