+ 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 did not authenticate at %llu", (unsigned long long) p);
+ r = -EBADMSG;
+ goto fail;
+ }
+
+ f->hmac_running = false;
+
+ last_tag = p + ALIGN64(le64toh(o->object.size));