commit fc771163d9f0aad72614e9806742a0a289e40644
parent cc66d00feafea5ac1fdb25db9364757229aa2641
Author: Alexander Hansen Færøy <ahf@torproject.org>
Date: Wed, 11 Feb 2026 22:56:27 +0100
Merge branch 'export-consensus' into 'main'
rename my-consensus-* to consensus-transparency-* at the right time
See merge request tpo/core/tor!962
Diffstat:
3 files changed, 69 insertions(+), 13 deletions(-)
diff --git a/changes/export-consensus b/changes/export-consensus
@@ -0,0 +1,4 @@
+ o Minor features (directory authority):
+ - Export unsigned consensus documents once we have seen a threshold
+ of signatures, as a step toward the consensus transparency
+ experiment.
diff --git a/src/app/main/main.c b/src/app/main/main.c
@@ -1064,6 +1064,13 @@ sandbox_init_filter(void)
if (authdir_mode(options)) {
RENAME_SUFFIX("my-consensus-microdesc", ".tmp");
RENAME_SUFFIX("my-consensus-ns", ".tmp");
+
+ sandbox_cfg_allow_rename(&cfg,
+ get_datadir_fname("my-consensus-microdesc"),
+ get_datadir_fname("consensus-transparency-microdesc"));
+ sandbox_cfg_allow_rename(&cfg,
+ get_datadir_fname("my-consensus-ns"),
+ get_datadir_fname("consensus-transparency-ns"));
}
#define STAT_DATADIR(name) \
diff --git a/src/feature/dirauth/dirvote.c b/src/feature/dirauth/dirvote.c
@@ -115,6 +115,9 @@ typedef struct pending_consensus_t {
char *body;
/** The parsed in-progress consensus document. */
networkstatus_t *consensus;
+ /** Have we reached the critical number of sigs on this consensus, and
+ * exported it for the consensus transparency module? */
+ bool have_exported_for_transparency;
} pending_consensus_t;
/* DOCDOC dirvote_add_signatures_to_all_pending_consensuses */
@@ -2374,6 +2377,21 @@ networkstatus_compute_consensus(smartlist_t *votes,
T, weight_scale);
}
+ /* Write the unsigned proposed consensus text to disk, for dir auth
+ * debugging purposes, and also to put a sig-less consensus file in
+ * place for (with luck) later export to the consensus transparency
+ * module. */
+ {
+ char *unsigned_consensus = smartlist_join_strings(chunks, "", 0, NULL);
+ char *filename = NULL;
+ tor_asprintf(&filename, "my-consensus-%s", flavor_name);
+ char *fpath = get_datadir_fname(filename);
+ write_str_to_file(fpath, unsigned_consensus, 0);
+ tor_free(filename);
+ tor_free(fpath);
+ tor_free(unsigned_consensus);
+ }
+
/* Add a signature. */
{
char digest[DIGEST256_LEN];
@@ -3486,16 +3504,6 @@ dirvote_compute_consensuses(void)
pending[flav].consensus = consensus;
n_generated++;
- /* Write it out to disk too, for dir auth debugging purposes */
- {
- char *filename;
- tor_asprintf(&filename, "my-consensus-%s", flavor_name);
- char *fpath = get_datadir_fname(filename);
- write_str_to_file(fpath, consensus_body, 0);
- tor_free(filename);
- tor_free(fpath);
- }
-
consensus_body = NULL;
consensus = NULL;
}
@@ -3561,9 +3569,36 @@ dirvote_compute_consensuses(void)
return -1;
}
-/** Helper: we just got the <b>detached_signatures_body</b> sent to us as
- * signatures on the currently pending consensus. Add them to <b>pc</b>
- * as appropriate. Return the number of signatures added. (?) */
+/** We just got enough sigs on the pending <b>flavor_name</b>-flavor
+ * consensus that it is time to export it to the consensus transparency
+ * module. We do this by writing a "consensus-transparency-%s" file which
+ * the module will detect and act on.
+ *
+ * The file needs to be just the bare consensus, with no signatures, so we
+ * are registering a hash that everybody can agree on. */
+static void
+export_consensus_for_transparency(const char *flavor_name)
+{
+ char *filename = NULL;
+ tor_asprintf(&filename, "my-consensus-%s", flavor_name);
+ char *fpath_from = get_datadir_fname(filename);
+ tor_free(filename);
+ tor_asprintf(&filename, "consensus-transparency-%s", flavor_name);
+ char *fpath_to = get_datadir_fname(filename);
+ tor_free(filename);
+
+ replace_file(fpath_from, fpath_to);
+
+ log_notice(LD_DIR, "Exported consensus transparency file %s.",
+ fpath_to);
+
+ tor_free(fpath_from);
+ tor_free(fpath_to);
+}
+
+/** Helper: we just received <b>sigs</b> as
+ * signatures on the currently pending consensus. Add them to <b>pc</b>
+ * as appropriate. Return the number of signatures added, or -1 if error. */
static int
dirvote_add_signatures_to_pending_consensus(
pending_consensus_t *pc,
@@ -3627,6 +3662,16 @@ dirvote_add_signatures_to_pending_consensus(
}
*msg_out = "Signatures added";
tor_free(new_signatures);
+
+ /* Check if we now have enough sigs that we are confident this
+ * will be our consensus. */
+ if (!pc->have_exported_for_transparency &&
+ networkstatus_check_consensus_signature(pc->consensus, -1) >= 0) {
+ /* Yes! Send it to the consensus transparency module. */
+ export_consensus_for_transparency(flavor_name);
+ pc->have_exported_for_transparency = 1;
+ }
+
} else if (r == 0) {
*msg_out = "Signatures ignored";
} else {
