Supported Operations

Supported Operations

wolfSPDM implements requester-side SPDM operations for session establishment, secure data exchange, attestation, and session maintenance, plus the TCG binding, TPM vendor commands, PSK and a responder for TPM builds.

Operation coverage

Operation	SPDM area	wolfSPDM API
Version negotiation	GET_VERSION	wolfSPDM_GetVersion
Capability negotiation	GET_CAPABILITIES	wolfSPDM_GetCapabilities
Algorithm negotiation	NEGOTIATE_ALGORITHMS	wolfSPDM_NegotiateAlgorithms
Certificate digest retrieval	GET_DIGESTS	wolfSPDM_GetDigests
Certificate chain retrieval	GET_CERTIFICATE	wolfSPDM_GetCertificate
Session key exchange	KEY_EXCHANGE	wolfSPDM_KeyExchange
Session finalization	FINISH	wolfSPDM_Finish
One-shot full connect	Full handshake	wolfSPDM_Connect
Secured app exchange	Secured messages	wolfSPDM_SecuredExchange
MCTP application messages	Secured messages (DSP0275)	wolfSPDM_SendData, wolfSPDM_ReceiveData
Caller-driven secured records	Secured messages	wolfSPDM_EncryptMessage, wolfSPDM_DecryptMessage
Large messages	CHUNK_SEND / CHUNK_GET	automatic once both sides set CHUNK_CAP
Measurements (signed/unsigned)	GET_MEASUREMENTS	wolfSPDM_GetMeasurements
Measurement block access	Measurement parsing	wolfSPDM_GetMeasurementCount, wolfSPDM_GetMeasurementBlock
Sessionless challenge auth	CHALLENGE / CHALLENGE_AUTH	wolfSPDM_Challenge
Keep-alive	HEARTBEAT	wolfSPDM_Heartbeat
Session key rotation	KEY_UPDATE	wolfSPDM_KeyUpdate
TCG binding session (TPM)	TCG SPDM binding, GIVE_PUB mutual auth	wolfSPDM_Connect in a Nuvoton or Nations mode
PSK session (TPM)	PSK_EXCHANGE / PSK_FINISH	wolfSPDM_SetPSK, wolfSPDM_Connect
Responder (fwTPM)	TCG binding and PSK responder	wolfSPDM_Resp* (spdm_responder.h)

Supported protocol versions

• SPDM 1.2 (0x12)
• SPDM 1.3 (0x13)
• SPDM 1.4 (0x14)

Maximum negotiated version can be capped with wolfSPDM_SetMaxVersion.

Fixed cryptographic profile (Algorithm Set B)

• Hash: SHA-384
• Asymmetric signature: ECDSA P-384
• Key exchange: ECDHE secp384r1
• AEAD: AES-256-GCM
• Key schedule: SPDM key schedule + HKDF-SHA384

Post-quantum cryptography (SPDM 1.4, optional)

When built against a wolfSSL with the matching support, wolfSPDM adds two independent post-quantum capabilities, each dual-stacked with the classical profile so the responder selects one:

• Signatures (ML-DSA, FIPS 204): advertises ML-DSA-44 / 65 / 87 in the 1.4 PqcAsymAlgo field alongside ECDSA P-384; verifies whichever was negotiated. See Post-Quantum ML-DSA.
• Key exchange (ML-KEM, FIPS 203): advertises ML-KEM-512 / 768 / 1024 as a KEMAlg struct alongside the ECDHE group; sends the encapsulation key and decapsulates the responder's ciphertext. Standalone (not hybrid). See Post-Quantum ML-KEM.

Enabling both yields a fully post-quantum SPDM handshake (ML-KEM key exchange + ML-DSA authentication). Large responses (e.g. an ML-DSA-87 signature, or ML-DSA + the ML-KEM ciphertext, exceeding the negotiated DataTransferSize) are reassembled with SPDM 1.2 message chunking (CHUNK_GET), and a large ML-KEM KEY_EXCHANGE request is split with CHUNK_SEND; see Message Chunking.

Notable implementation scope

• Standard requester for standards-based SPDM peers and DMTF spdm-emu; the responder covers the TCG binding and PSK used by wolfTPM's fwTPM
• Build switches compile out either side (see Configuration and Macros)
• Trust anchor support via wolfSPDM_SetTrustedCAs (single DER CA cert buffer)