Merge #248: bppp: Fix and improve test for invalid sign byte

3372993 bppp: Fix test for invalid sign byte (Tim Ruffing) Pull request description: ACKs for top commit: jonasnick: ACK 3372993 Tree-SHA512: cfc317b47dc731b419cc88d0c5292cb6b3ca9e28c937d316f63940be6ad4607056ece81136ca1226f94dbf26cfe0492f5d27f4cfa473cf46898474b342a55593
BlockstreamResearch · Jul 21, 2023 · afe7e64 · afe7e64
2 parents 1a6d93f + 3372993
commit afe7e64
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/src/modules/bppp/tests_impl.h b/src/modules/bppp/tests_impl.h
@@ -257,7 +257,11 @@ void test_serialize_two_points(void) {
         random_group_element_test(&X);
         random_group_element_test(&R);
         secp256k1_bppp_serialize_points(buf, &X, &R);
-        buf[0] |= 4 + (unsigned char)secp256k1_testrandi64(4, 255);
+
+        buf[0] = 4 + (unsigned char)secp256k1_testrandi64(0, 253);
+        /* Assert that buf[0] is actually invalid. */
+        CHECK(buf[0] != 0x02 && buf[0] != 0x03);
+
         CHECK(!secp256k1_bppp_parse_one_of_points(&X_tmp, buf, 0));
         CHECK(!secp256k1_bppp_parse_one_of_points(&R_tmp, buf, 0));
     }