byte-array-ops

IMPORTANT: Crate Split in v0.3.0

Starting with v0.3.0, security hardening features will be moved to a separate crate. This crate will remain focused on general-purpose byte array operations. See the Security Hardening section for details.

Active Development Warning This library is under heavy active development. Core functionality (type conversions, bitwise operations) is stable and production ready.

Overview

A no_std-compatible Rust library for ergonomic byte array operations with optional security hardening.

Design Philosophy:

• Compile only what you need - Feature flags for graceful degradation. Basic conversions work without any features, bitwise operations require ops_algebra (enabled by default), and security features are opt-in.
• Minimal dependencies - Keep compilation fast and dependency tree small for a pleasant development experience.
• Test-driven development - No functionality is added without comprehensive test coverage. Untested or experimental features are gated behind the experimental flag (disabled by default and guarded with compile_error!).

Features

Note on Feature Selection:

• No features needed: Simple conversions (hex ↔ bytes, UTF-8 ↔ bytes) work with default-features = false
• ops_algebra (default): Enabled by default for bitwise operations
• Security features: Moved to a separate crate in v0.3.0 - see Security Hardening section

Installation

[dependencies]
byte-array-ops = "0.1.0"

# Or disable default features for minimal build (conversions only)
byte-array-ops = { version = "0.1.0", default-features = false }

# For no_std environments with alloc and operations
byte-array-ops = { version = "0.1.0", default-features = false, features = ["ops_algebra"] }

Quick Start

See the API documentation for comprehensive examples including:

• Creating ByteArrays from hex, binary, UTF-8, and raw bytes
• Bitwise operations (XOR, AND, OR, NOT)
• Working with iterators
• Convenience macros (try_bytes!, try_hex!, try_bin!)

CAVEAT: The try_bytes! macro silently converts to UTF-8 when no format prefix (0x, 0b, 0o) is provided. Use try_hex! or try_bin! for guaranteed hex/binary parsing without format detection.

Basic Example

use byte_array_ops::ByteArray;
use byte_array_ops::errors::ByteArrayError;
use byte_array_ops::{try_hex, try_bin};

fn main() -> Result<(),ByteArrayError> {

    // From hex string (using parse)
    let from_hex: ByteArray = "0xdeadbeef".parse()?;
    assert_eq!(from_hex.as_bytes(), [0xde, 0xad, 0xbe, 0xef]);

    // Using macros for convenience
    let with_macro = try_hex!("cafe")?;
    assert_eq!(with_macro.as_bytes(), [0xca, 0xfe]);

    let binary = try_bin!("11110000")?;
    assert_eq!(binary.as_bytes(), [0xf0]);

    // From UTF-8 string (no prefix)
    let from_utf8: ByteArray = "hello".parse()?;
    assert_eq!(from_utf8.as_bytes(), b"hello");

    // Bitwise operations (requires ops_algebra feature)
    let a: ByteArray = "0xff00".parse()?;
    let b: ByteArray = "0x0ff0".parse()?;
    let result = a ^ b; // XOR
    assert_eq!(result.as_bytes(), [0xf0, 0xf0]);
    
    Ok(())
}

no_std Support

This library is no_std compatible and requires only the alloc crate. Perfect for:

• Embedded systems with allocators (ESP32, ARM Cortex-M with heap)
• Bootloaders and kernel development
• WebAssembly environments
• Any environment where std is unavailable

Roadmap

Note on version stability: All versions post-0.2.0 are subject to change depending on whether breaking changes are necessary in previous versions. When no more breaking API changes are planned, the "Active Development Warning" banner above will be removed. This is expected to happen well before v1.0.0 as the API matures for ergonomic use.

v0.1.0 (Old Milestone)

Core functionality with production-ready type conversions and bitwise operations:

• Multiple input formats (hex, binary, UTF-8, raw bytes)
• Bitwise operations (XOR, AND, OR, NOT)
• Comprehensive iterator support
• no_std compatibility with alloc

v0.2.0 (Current)

API refinement and macro ergonomics:

• Cleanup API and experiment with most efficient (and most used) APIs
• Lay the groundwork for introducing the SecureReallocationProvider trait, which will encompass more secure implementations of vector methods that may require allocation
• Introduce helper macros for ByteArray construction

v0.3.0 (Planned - Possible Breaking Changes)

Security hardening for cryptographic and sensitive data use cases:

• Secure memory wiping (zeroize on drop)
• Memory locking (prevent swapping to disk)
• Constant-time operations (timing attack prevention)
• Hardened constructors and secure reallocation
• Bugfixes and refinements

v0.4.0 (Planned - Possible Breaking Changes)

Performance optimization for high-throughput scenarios:

• SIMD-accelerated bitwise operations
• Benchmark suite and regression testing
• Performance tuning for large arrays

v1.0.0 (Future)

Stable API with long-term compatibility guarantees:

• API freeze after real-world usage validation
• Security audit (if feasible - even major libraries like RustCrypto often lack formal audits)
• Comprehensive test coverage and fuzzing
• Multi-platform testing and verification

Security Hardening

As of v0.3.0, security hardening features have been moved to a separate crate.

Why the Split?

Due to inherent design requirements, secure and general-purpose byte array operations cannot coexist in the same crate without maintenance issues:

Technical Constraints:

• Additive features requirement: Rust features should be additive to avoid breaking changes upon feature activation/deactivation
• Type divergence: Constant-time operations require different types and function signatures that are incompatible with general-purpose use
• API restrictions: General-purpose use needs to deref Vec<_> to access standard methods, but secure versions must restrict these due to reallocation and data remnants concerns
• Security guarantees: Hardened types cannot provide all standard Vec operations without compromising security

Migration Path

Current users (v0.2.x):

• This crate (byte-array-ops) will continue as a general-purpose byte array library
• No action needed for general-purpose use cases

Users needing security hardening:

• Security features (zeroize, constant-time ops, memory locking, memory encryption) will be available in a separate crate starting v0.3.0
• The secure crate will depend on this crate for core functionality
• Documentation for the secure crate will be provided upon release

For historical reference on planned security features, see archive/security_features.md.

License

Licensed under the Apache License, Version 2.0. See LICENSE for details.