Allow more hashes in vote

nano/node/messages.cpp

@@ -526,9 +526,10 @@ nano::confirm_req::confirm_req (nano::network_constants const & constants, std::
 	message (constants, nano::message_type::confirm_req),
 	roots_hashes (roots_hashes_a)
 {
+	debug_assert (roots_hashes.size () <= nano::vote::max_hashes);
+
 	// not_a_block (1) block type for hashes + roots request
 	header.block_type_set (nano::block_type::not_a_block);
-	debug_assert (roots_hashes.size () < 16);
 	header.count_set (static_cast<uint8_t> (roots_hashes.size ()));
 }
 
@@ -537,9 +538,10 @@ nano::confirm_req::confirm_req (nano::network_constants const & constants, nano:
 	roots_hashes (std::vector<std::pair<nano::block_hash, nano::root>> (1, std::make_pair (hash_a, root_a)))
 {
 	debug_assert (!roots_hashes.empty ());
+	debug_assert (roots_hashes.size () <= nano::vote::max_hashes);
+
 	// not_a_block (1) block type for hashes + roots request
 	header.block_type_set (nano::block_type::not_a_block);
-	debug_assert (roots_hashes.size () < 16);
 	header.count_set (static_cast<uint8_t> (roots_hashes.size ()));
 }
 
@@ -684,7 +686,6 @@ nano::confirm_ack::confirm_ack (nano::network_constants const & constants, std::
 	vote (vote_a)
 {
 	header.block_type_set (nano::block_type::not_a_block);
-	debug_assert (vote_a->hashes.size () < 16);
 	header.count_set (static_cast<uint8_t> (vote_a->hashes.size ()));
 }
 

nano/secure/vote.cpp

@@ -13,11 +13,15 @@ nano::vote::vote (nano::account const & account_a, nano::raw_key const & prv_a,
 	timestamp_m{ packed_timestamp (timestamp_a, duration) },
 	account{ account_a }
 {
+	debug_assert (hashes.size () <= max_hashes);
+
 	signature = nano::sign_message (prv_a, account_a, hash ());
 }
 
 void nano::vote::serialize (nano::stream & stream_a) const
 {
+	debug_assert (hashes.size () <= max_hashes);
+
 	write (stream_a, account);
 	write (stream_a, signature);
 	write (stream_a, boost::endian::native_to_little (timestamp_m));
@@ -36,7 +40,7 @@ bool nano::vote::deserialize (nano::stream & stream_a)
 		nano::read (stream_a, signature.bytes);
 		nano::read (stream_a, timestamp_m);
 
-		while (stream_a.in_avail () > 0)
+		while (stream_a.in_avail () > 0 && hashes.size () < max_hashes)
 		{
 			nano::block_hash block_hash;
 			nano::read (stream_a, block_hash);

nano/secure/vote.hpp

@@ -57,6 +57,8 @@ class vote final
 	static uint64_t constexpr timestamp_min = { 0x0000'0000'0000'0010ULL };
 	static uint8_t constexpr duration_max = { 0x0fu };
 
+	static std::size_t constexpr max_hashes = 256;
+
 	/* Check if timestamp represents a final vote */
 	static bool is_final_timestamp (uint64_t timestamp);