Streamable size limits by arvidn · Pull Request #1423 · Chia-Network/chia_rs

arvidn · 2026-04-28T07:29:29Z

This adds an option to the streamable macro, to specify a limit on vectors in streamable types. It can short cut some validation by failing earlier for messages that are invalid.

The second commit employs the new option to set appropriate limits for some message types.

Note

Medium Risk
Changes deserialization behavior for Streamable structs by enforcing new per-field vector length limits, which can cause previously-accepted oversized network messages to be rejected. Risk is moderate because it touches core protocol parsing but is additive and guarded by explicit #[chia(max_length = ...)] annotations.

Overview
Adds a new #[chia(max_length = N)] field attribute to the Streamable derive macro to enforce bounded parsing for Vec<T> and Option<Vec<T>>, failing early with Error::SequenceTooLarge.

Refactors vector parsing in chia-traits to route through a shared parse_vec_with_max_length helper and adds tests covering bounded Vec/Option<Vec> behavior.

Applies explicit maximum lengths to several full node and wallet protocol message fields (e.g., block/header responses, additions/removals queries, subscription update payloads, mempool notifications) to cap decoded list sizes.

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Copilot

Pull request overview

Adds bounded vector parsing to the Streamable derive to fail early on oversized protocol payloads, and applies explicit max-length limits to selected full node and wallet message types.

Changes:

Introduces #[chia(max_length = N)] on Streamable-derived fields to bound Vec<T> / Option<Vec<T>> parsing.
Adds parse_vec_with_max_length() to chia-traits plus unit tests for bounded parsing behavior.
Annotates various protocol message vector fields with concrete max_length limits to prevent oversized allocations/validation work.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 5 comments.

File	Description
crates/chia_streamable_macro/src/lib.rs	Extends the derive macro to parse `#[chia(max_length = ...)]` and generate bounded parsing for supported vector fields.
crates/chia-traits/src/streamable.rs	Adds `parse_vec_with_max_length()` and tests validating bounded vector/optional-vector parsing failures.
crates/chia-protocol/src/wallet_protocol.rs	Applies `max_length` bounds to multiple wallet protocol message vectors.
crates/chia-protocol/src/full_node_protocol.rs	Applies `max_length` bound to `RespondBlocks.blocks`.

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Copilot · 2026-04-28T07:38:14Z

                    Ok(())
                }
                fn parse<const TRUSTED: bool>(input: &mut std::io::Cursor<&[u8]>) -> #crate_name::chia_error::Result<Self> {
-                    Ok(Self { #( #fnames: <#ftypes as #crate_name::Streamable>::parse::<TRUSTED>(input)?, )* })
+                    Ok(Self { #( #fnames: #parse_exprs, )* })
                }


The new max_length support is enforced only during parse(). The derived stream() implementation still allows serializing vectors longer than max_length, which can let the code construct and emit protocol messages that peers (or future local parsing) will reject. Consider also generating a length check in stream() for bounded fields (returning Error::SequenceTooLarge) to keep the invariant consistent in both directions.

coveralls-official · 2026-04-28T08:17:06Z

Coverage Report for CI Build 25061556133

Warning

Build has drifted: This PR's base is out of sync with its target branch, so coverage data may include unrelated changes.
Quick fix: rebase this PR. Learn more →

Coverage increased (+0.03%) to 80.732%

Details

Coverage increased (+0.03%) from the base build.
Patch coverage: 5 uncovered changes across 1 file (95 of 100 lines covered, 95.0%).
No coverage regressions found.

Uncovered Changes

File	Changed	Covered	%
crates/chia_streamable_macro/src/lib.rs	54	49	90.74%

Coverage Regressions

No coverage regressions found.

Coverage Stats


Relevant Lines:	18461
Covered Lines:	14904
Line Coverage:	80.73%
Coverage Strength:	12217114.08 hits per line

💛 - Coveralls

Rigidity · 2026-04-28T13:01:56Z


 #[streamable(message)]
 pub struct RequestPuzzleState {
+    #[chia(max_length = 32700)]


If register_for_coin_updates and register_for_ph_updates can allow 1.6 million, so should these. This limit is insufficient for wallets like Sage to function. Many wallets have over this many puzzle hashes to subscribe to (each one is a wallet address).

the 1.6 million is derived from the 50 MiB message limit, which will not fit more 32 byte hashes.

Does Sage subscribe to all coins in a single request? This number was picked based on CoinStore.MAX_PUZZLE_HASH_BATCH_SIZE, see: https://github.com/Chia-Network/chia-blockchain/blob/main/chia/full_node/full_node_api.py#L1949

The limit is defined here: https://github.com/Chia-Network/chia-blockchain/blob/main/chia/full_node/coin_store.py#L444

It seems like we silently drop any item past this limit.

Rigidity · 2026-04-28T13:02:45Z


 #[streamable(message)]
 pub struct RespondPuzzleState {
+    #[chia(max_length = 32700)]


Same as above

Rigidity · 2026-04-28T13:02:50Z

    height: u32,
    header_hash: Bytes32,
    is_finished: bool,
+    #[chia(max_length = 32700)]


Same as above

Rigidity · 2026-04-28T13:02:56Z


 #[streamable(message)]
 pub struct RequestCoinState {
+    #[chia(max_length = 32700)]


Same as above

Rigidity · 2026-04-28T13:03:08Z


 #[streamable(message)]
 pub struct RespondCoinState {
+    #[chia(max_length = 32700)]


Same as above

Rigidity · 2026-04-28T13:03:14Z

 pub struct RespondCoinState {
+    #[chia(max_length = 32700)]
    coin_ids: Vec<Bytes32>,
+    #[chia(max_length = 32700)]


Same as above

cursor

Cursor Bugbot has reviewed your changes and found 2 potential issues.

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cursor · 2026-04-28T15:24:33Z

    height: u32,
    header_hash: Bytes32,
    is_finished: bool,
+    #[chia(max_length = 500000)]


Inconsistent puzzle hash limits between request and response

Medium Severity

RequestPuzzleState accepts up to 35000 puzzle hashes while RespondPuzzleState only allows 33000. Since the response echoes back the requested puzzle hashes, a peer accepting a request near the upper limit cannot generate a response that successfully parses on the other side, producing an unrecoverable protocol failure for otherwise valid requests.

^{Reviewed by Cursor Bugbot for commit 8c79e84. Configure here.}

cursor · 2026-04-28T15:24:33Z

    header_hash: Bytes32,
+    #[chia(max_length = 30000)]
    coins: Vec<(Bytes32, Vec<Coin>)>,
+    #[chia(max_length = 30000)]


Vec size limits may break existing wallet clients

Medium Severity

The 30000/35000 caps on puzzle_hashes/coin_names in RequestRemovals, RequestAdditions, RequestPuzzleState, RespondPuzzleState, and CoinStateUpdate are far below the 1_600_000 used for RegisterForPhUpdates/RegisterForCoinUpdates. Wallets that currently operate with more puzzle hashes per request (each address counts as a hash) will see legitimate messages rejected with SequenceTooLarge after this change.

Additional Locations (1)

crates/chia-protocol/src/wallet_protocol.rs#L265-L285

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add macro option to limit the size of Vec in streamable types

5404247

arvidn requested review from Rigidity and Copilot April 28, 2026 07:33

Copilot started reviewing on behalf of arvidn April 28, 2026 07:33 View session

cursor Bot reviewed Apr 28, 2026

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Comment thread crates/chia-traits/src/streamable.rs

Copilot AI reviewed Apr 28, 2026

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impose vector-limits on some messages

652502a

arvidn force-pushed the streamable-size-limits branch from 2f5d61a to 652502a Compare April 28, 2026 08:47

cursor Bot reviewed Apr 28, 2026

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Comment thread crates/chia-protocol/src/wallet_protocol.rs Outdated

arvidn requested a review from emlowe April 28, 2026 11:28

Rigidity reviewed Apr 28, 2026

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update limits

8c79e84

cursor Bot reviewed Apr 28, 2026

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Rigidity approved these changes Apr 30, 2026

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Pull request overview

Reviewed changes

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coveralls-official Bot commented Apr 28, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Coverage Report for CI Build 25061556133

Coverage increased (+0.03%) to 80.732%

Details

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Inconsistent puzzle hash limits between request and response

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Vec size limits may break existing wallet clients

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arvidn commented Apr 28, 2026 •

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