OCPP-RS

Rust protocol library for the Open Charge Point Protocol (OCPP).

Supports OCPP 1.6 (JSON) and OCPP 2.1 (additive / 2.0.1-compatible schemas).

Features

Full OCPP 1.6 and 2.1 message payloads + OCPP-J parse/serialize
CallResult typing via PendingCalls / action-name correlation
Typed RPC framework error codes
Optional payload length/bounds checks (schema_validate) and device-model catalogs
#![no_std] + alloc — zero std in library code (global allocator required on baremetal)

Install

[dependencies]
ocpp-rs = "0.4"

# Optional:
# features = ["schema_validate", "device_model_catalog", "datetime_serialize_rfc3339"]

Feature	Purpose
`schema_validate`	Enforce string/array/numeric bounds on CALL (and 2.1 SEND) payloads after parse
`device_model_catalog`	Standard 2.1 component/variable name tables
`datetime_serialize_rfc3339`	Emit RFC3339 millis instead of `%.3fZ`

MSRV: 1.85 (edition 2024).

Upgrading from 0.2.x: guides/migration-0.4.md.

`no_std` / firmware

[dependencies]
ocpp_rs = { version = "0.4", default-features = false }
# plus your allocator / #[global_allocator]

cargo build --lib
cargo build --lib --target thumbv7em-none-eabi   # optional freestanding check
cargo tree -p chrono -f '{p} {f}' | head -5       # expect: alloc,serde (not std/clock)

OCPP 1.6 CallResult

CALLRESULT has no action on the wire. Blind parse yields CallResultRaw. Correlate with PendingCalls:

use ocpp_rs::v16::call::{Action, Call, Heartbeat};
use ocpp_rs::v16::parse::TypedMessage;
use ocpp_rs::v16::pending::PendingCalls;
use ocpp_rs::v16::typed_call_result::TypedCallResult;

let mut pending = PendingCalls::new();
let _wire = pending.send_call(Call::new("1".into(), Action::Heartbeat(Heartbeat {})))?;
let typed = pending.deserialize_typed(r#"[3, "1", {"currentTime": "2024-01-01T00:00:00.000Z"}]"#)?;
assert!(matches!(typed, TypedMessage::CallResult(TypedCallResult::Heartbeat(_))));

Sticky sessions or Redis messageId → action name + resolve_with_action_name
Datetime: RFC3339 parse; serialize defaults to %.3fZ — guides/datetime-features.md
Details: v16::pending, migration guide

OCPP 2.1

Same correlation model under v21::pending. Framing types 2–6 (CALL, CALLRESULT, CALLERROR, CALLRESULTERROR, SEND).

use ocpp_rs::v21::call::{Action, Call};
use ocpp_rs::v21::messages::heartbeat::HeartbeatRequest;
use ocpp_rs::v21::parse::TypedMessage;
use ocpp_rs::v21::pending::PendingCalls;
use ocpp_rs::v21::typed_call_result::TypedCallResult;

let mut pending = PendingCalls::new();
let call = Call::new(
    "1".into(),
    Action::Heartbeat(HeartbeatRequest { custom_data: None }),
);
assert_eq!(call.action_kind(), "Heartbeat");
let _wire = pending.send_call(call)?;
let typed = pending.deserialize_typed(
    r#"[3, "1", {"currentTime": "2024-01-01T00:00:00.000Z"}]"#,
)?;
assert!(matches!(
    typed,
    TypedMessage::CallResult(TypedCallResult::Heartbeat(_))
));

2.0.1 subprotocol gating: guides/ocpp-2.0.1.md.

Load-balanced resolve

use ocpp_rs::v21::pending::resolve_with_action_name;
use ocpp_rs::v21::parse::{deserialize_to_message, Message};

let Message::CallResult(raw) = deserialize_to_message(wire)? else { /* … */ };
let typed = resolve_with_action_name(raw, &redis_getdel(&raw.unique_id)?)?;

Example crate

cd example && cargo run

Covers 1.6 and 2.1: PendingCalls correlation, CALL / CALLRESULT / CALLERROR, and 2.0.1 subprotocol gating.

Example (1.6 CALL)

use ocpp_rs::v16::parse::{self, Message};
use ocpp_rs::v16::call::Action;

let incoming_text = r#"[2, "19223201", "BootNotification", {"chargePointVendor":"VendorX","chargePointModel":"SingleSocketCharger"}]"#;
let incoming_message = parse::deserialize_to_message(incoming_text)?;
if let Message::Call(call) = incoming_message {
    match call.payload {
        Action::BootNotification(_boot) => { /* … */ }
        _ => {}
    }
}

Out of scope

This is a protocol wire crate, not a full stack:

No SOAP / HTTP binding for 1.6
No WebSocket, TLS, or Security Profile handshake
No Charge Point / CSMS state machines or certification test runners

Contributing

Add or update tests with behavior changes.

Fuzzing

Requires nightly + cargo-fuzz:

rustup toolchain install nightly -c rust-src
cargo +nightly install cargo-fuzz

Target	What it feeds the parser
`v16_deserialize` / `v21_deserialize`	Raw bytes as UTF-8
`v16_roundtrip` / `v21_roundtrip`	Raw bytes; if parse OK, serialize → reparse
`v16_structured` / `v21_structured`	Valid-looking OCPP-J frames (real actions, RPC codes, bounded JSON)
`v16_corrupt` / `v21_corrupt`	Seed / structured frames + truncations, bit flips, bad UTF-8, wrong arity, …

./fuzz/run_all.sh              # all v16 + v21 targets (300s, 4 workers each)
./fuzz/run_v16.sh              # OCPP 1.6 only
./fuzz/run_v21.sh              # OCPP 2.1 only
./fuzz/run_v21.sh 600 8        # longer / more workers

./fuzz/clean.sh                # artifacts, logs, hash corpus, fuzz/target (keeps *.json seeds)
./fuzz/clean.sh --keep-corpus  # leave discovered hash inputs
./fuzz/clean.sh --keep-target  # leave fuzz/target build cache

Or run a single target manually:

# One target, 5 minutes, 8 workers
cargo +nightly fuzz run v21_corrupt --fuzz-dir fuzz -- -max_total_time=300 -jobs=8 -workers=8

Discovered corpus inputs under fuzz/corpus/ are gitignored (seed *.json only). Regenerate action seeds from exhaust tests: python3 tools/gen_fuzz_corpus.py.

License: MIT.

ocpp_rs 0.4.2