GitHub - wolfSSL/wolfCOSE: A fast, portable, and lightweight COSE + CBOR implementation for embedded systems. Supports PQC, FIPS 140-3, DO-178, and MISRA C. Powered by wolfSSL.

wolfCOSE is a lightweight C library implementing CBOR (RFC 8949) and COSE (RFC 9052/9053) using wolfSSL as the crypto backend. Main Features

Complete RFC 9052 message set: all six COSE message types, including multi-signer COSE_Sign and multi-recipient COSE_Encrypt / COSE_Mac Post-quantum signing: ML-DSA (Dilithium) at all three security levels 40 algorithms across signing, encryption, MAC, and key distribution Zero dynamic allocation: all operations use caller-provided buffers Tiny footprint: 7.5 KB .text minimal build (Sign1+ECC), 25.6 KB full (40 algorithms), zero .data/.bss Full COSE lifecycle in ~<1KB RAM (excluding wolfCrypt internals) Path to FIPS 140-3 via wolfCrypt FIPS Certificate #4718 (sole crypto dependency)

Supported Algorithms Signing: ES256, ES384, ES512, EdDSA (Ed25519/Ed448), PS256/384/512, ML-DSA-44/65/87 Encryption: AES-GCM (128/192/256), ChaCha20-Poly1305, AES-CCM variants MAC: HMAC-SHA256/384/512, AES-MAC Key Distribution: Direct, AES Key Wrap, ECDH-ES+HKDF COSE Message Types (RFC 9052) wolfCOSE has implemented all RFC 9052 messages both single-actor and multi-actor variants:

Message RFC 9052 API Purpose

COSE_Sign1 Sec. 4.2 wc_CoseSign1_Sign / wc_CoseSign1_Verify Single-signer signature

COSE_Sign Sec. 4.1 wc_CoseSign_Sign / wc_CoseSign_Verify Multi-signer (independent signatures over the same payload)

COSE_Encrypt0 Sec.

5.2 wc_CoseEncrypt0_Encrypt / wc_CoseEncrypt0_Decrypt Single-recipient AEAD

COSE_Encrypt Sec. 5.1 wc_CoseEncrypt_Encrypt / wc_CoseEncrypt_Decrypt Multi-recipient (one ciphertext, many recipients via Direct / AES-KW / ECDH-ES)

COSE_Mac0 Sec. 6.2 wc_CoseMac0_Create / wc_CoseMac0_Verify Single-recipient MAC

COSE_Mac Sec. 6.1 wc_CoseMac_Create / wc_CoseMac_Verify Multi-recipient MAC (shared MAC key, distributed to recipients)

COSE_Key / COSE_KeySet Sec. 7 wc_CoseKey_Encode / wc_CoseKey_Decode Key serialization for all key types

Prerequisites (wolfSSL) wolfCOSE requires wolfSSL as its crypto backend. Minimum supported version: v5.8.0-stable (first release with the public wc_ForceZero symbol alongside the FIPS 204 final ML-DSA and context-aware wc_dilithium_*_ctx_msg APIs). Older 5.x releases can technically be supported but require source-level changes; contact wolfSSL for commercial support. Choose a build configuration based on the algorithms you need. Minimal Build (ECC + AES-GCM) This gives you COSE Sign1 (ES256/384/512) and Encrypt0 (AES-GCM): cd wolfssl ./autogen.sh ./configure --enable-ecc --enable-aesgcm \ --enable-sha384 --enable-sha512 --enable-keygen make && sudo make install sudo ldconfig Algorithms enabled: ES256, ES384, ES512, AES-GCM-128/192/256

Minimal Build (Post-Quantum / ML-DSA only) For pure post-quantum signing with ML-DSA-44/65/87: cd wolfssl ./autogen.sh ./configure --enable-cryptonly --enable-dilithium make && sudo make install sudo ldconfig Algorithms enabled: ML-DSA-44, ML-DSA-65, ML-DSA-87 (SHAKE-128/256 are pulled in automatically by --enable-dilithium.) Full Build (All Algorithms) cd wolfssl ./autogen.sh ./configure --enable-ecc --enable-ed25519 --enable-ed448 \ --enable-curve25519 --enable-aesgcm --enable-aesccm \ --enable-sha384 --enable-sha512 --enable-keygen \ --enable-rsapss --enable-chacha --enable-poly1305 \ --enable-dilithium --enable-hkdf --enable-aeskeywrap make && sudo make install sudo ldconfig Build # Core library (libwolfcose.a) make

# Run unit tests make test

# Build and run CLI tool round-trip tests (all algorithms) make tool-test

# Run lifecycle demo (11 algorithms) make demo Build Targets

Target Description

make all Build libwolfcose.a (core library only)

make shared Build libwolfcose.so

make test Build + run CBOR and COSE unit tests

make tool Build CLI tool (tools/wolfcose_tool)

make tool-test Round-trip self-test for all 17 algorithms

make demo Build + run lifecycle demo (11 algorithms)

make clean Remove all build artifacts

Quick Start Examples See examples/ for complete working code:

sign1_demo.c, encrypt0_demo.c, mac0_demo.c: algorithm demos lifecycle_demo.c: full edge-to-cloud workflow

comprehensive/: algorithm matrix tests scenarios/: firmware signing, attestation, fleet config

CI / Testing Runs on every push and PR:

Build + Test: Ubuntu, macOS, GCC 10-14, Clang 14-18 Comprehensive Tests: ~240 algorithm combination tests Static Analysis: cppcheck, Clang analyzer, GCC -fanalyzer MISRA C 2012: cppcheck --addon=misra checking all wolfCOSE code paths MISRA C 2023: strict GCC warnings and clang-tidy (bugprone-*, cert-*, clang-analyzer-*, misc-*) Coverity Scan: nightly defect analysis Advanced Internal Static Analysis: Fenrir wolfssl advanced static analysis tools Code Coverage: 99.3% for wolfcose.c, 100% for wolfcose_cbor.c

make coverage # Run tests with gcov make coverage-force-failure # Include crypto failure path testing

Documentation Full documentation is available in the Wiki:

Getting Started: Build instructions and first steps Message Types: All six RFC 9052 messages (Sign1, Sign, Encrypt0, Encrypt, Mac0, Mac) with code samples Algorithms: Complete list of 40 supported algorithms with COSE IDs API Reference: Function signatures, data structures, error codes Macros: Compile-time configuration options Testing: Test infrastructure, coverage, and failure injection MISRA Compliance: MISRA C:2012 and C:2023 compliance status and deviation rationale Project Structure: Source file layout

Blogs Blogs and update can be found here: wolfCOSE Blogs License wolfCOSE is free software licensed under the GPLv3. Copyright (C) 2026 wolfSSL Inc. Support

Note: While wolfCOSE is currently maintained by wolfSSL developers, it is not yet classified as an officially supported product. It was designed from the ground up to meet the same quality standards as the rest of the wolfSSL suite with future adoption in mind.

We are eager to transition this to a fully supported product as demand grows; if your organization requires official support or has specific feature requirements or you just have general questions or guidance with product, please reach out.

For commercial licensing, professional support contracts, or to discuss moving wolfCOSE into your production environment, contact wolfSSL.