autosar-e2e

A Rust implementation of the AUTOSAR E2E (End-to-End) Protection Protocol.

Overview

This library implements the AUTOSAR E2E protection mechanism which provides end-to-end data protection for safety-critical automotive communication systems. The E2E protection helps detect:

• Data Corruption: Through CRC checksums
• Message Loss/Duplication: Through sequence counters
• Incorrect Addressing: Through Data ID verification

Features

• Profile 11 implementation (variants 11A and 11C)
• Profile 22 implementation
• Profile 4 implementation
• Support for Protect, Check operations
• Comprehensive documentation and tests
• Configurable parameters per AUTOSAR specification

Installation

Add this to your Cargo.toml:

[dependencies]

autosar-e2e = "0.3.0"

Usage

Basic Example

use autosar_e2e::{E2EProfile, E2EResult, E2EStatus};
use autosar_e2e::profile11::{Profile11, Profile11Config, Profile11Variant};

fn main() -> E2EResult<()> {
    // Configure Profile 11
    let config = Profile11Config {
        mode: Profile11IdMode::Nibble,
        data_id : 0x123,
        max_delta_counter: 1,
        ..Default::default()
    };

    // Create sender and receiver instances
    let mut sender = Profile11::new(config.clone());
    let mut receiver = Profile11::new(config);

    // Prepare data to send
    let mut data = vec![0x00, 0x00, 0x12, 0x34, 0x56, 0x78, 0x9A, 0xBC]; // [CRC, counter, user data ..]
    
    // Add E2E protection
    sender.protect(&mut data)?;
    println!("Protected data: {:02X?}", data);

    // Simulate transmission...
    
    // Verify E2E protection at receiver
    match receiver.check(&data)? {
        E2EStatus::Ok => println!("Data integrity verified!"),
        E2EStatus::CrcError => println!("CRC error detected!"),
        E2EStatus::DataIdError => println!("Data ID mismatch!"),
        _ => println!("Counter sequence error!"),
    }

    Ok(())
}

Profiles

Profile 11 Specifications

Profile 11 Data Layout

Basically, Profile 11 uses a 2-byte header. If crc offset is zero, data layout is as the below.

Byte 0: CRC-8
Byte 1: [DataIDNibble(4 bits) | Counter(4 bits)]
Bytes 2-n: User Data

If crc offset is 64 and distance among crc, nibble and counter is the same, data layout is as the below.

Byte 0-7: User Data
Byte 8: CRC-8
Byte 9: [DataIDNibble(4 bits) | Counter(4 bits)]
Bytes 10-n: User Data

Profile 11 Modes

• Both(11A): DataIDNibble field can be used for user data
• Nibble(11C): DataIDNibble field is used for protection

Profile 11 Configuration Parameters

Profile 22 Specifications

Profile 22 Data Layout

Byte 0-7: User Data
Byte 8: CRC-8
Byte 9: [User Data | Counter(4 bits)]
Bytes 10-n: User Data

Profile 22 Configuration Parameters

Profile 4 Specifications

Profile 4 Data Layout

Byte 0-1: Data Length
Byte 2-3: Counter
Byte 4-7: Data ID
Bytes 8-11: Crc

Profile 4 Configuration Parameters

Architecture

The library follows a trait-based design for extensibility:

pub trait E2EProfile {
    type Config;
    
    fn new(config: Self::Config) -> Self;
    fn protect(&mut self, data: &mut Vec<u8>) -> E2EResult<()>;
    fn check(&mut self, data: &[u8]) -> E2EResult<E2EStatus>;
}

This design allows for easy addition of other E2E profiles in the future.

Testing

Run the test suite:

cargo test

Run tests with coverage:

cargo tarpaulin --out Html

Safety and Correctness

• All CRC calculations use the standard crc crate with AUTOSAR polynomial
• Counter wrap-around is handled correctly
• Comprehensive test coverage including edge cases
• No unsafe code

Future Work

• Add Profile 5 support
• Add Profile 6 support
• Add Profile 7 support
• Add Profile 8 support
• Performance benchmarks
• Async support

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is dual-licensed under either:

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

References

• AUTOSAR E2E Protocol Specification
• AUTOSAR Classic Platform

Disclaimer

This is an independent implementation and is not officially affiliated with or endorsed by AUTOSAR.