| # SPDM |
| |
| SPDM OpenPRoT devices shall use SPDM to conduct all attestation operations both |
| with downstream devices (as a requester) and upstream devices (as a responder.) |
| Devices may choose to act as a requester, a responder, or both. All SPDM version |
| references assume alignment with the most recently released versions of the spec. |
| |
| ## OCP Attestation Spec 1.1 Alignment |
| |
| OpenPRoT implementations of SPDM must align with the |
| [OCP Attestation Spec 1.1](https://github.com/google/spdm-accelerator-requirement/blob/main/OCP-Attestation-v1.1.docx.pdf). |
| All following sections have taken this spec into account. Please refer to that |
| specification for details on specific requirements. |
| |
| ## Baseline Version |
| |
| OpenPRoT sets a baseline version of SPDM 1.2. |
| |
| ## Requesters |
| |
| OpenPRoT devices implementing an SPDM requester will implement support for SPDM |
| 1.2 minimum and may implement SPDM 1.3 and up. The minimum and maximum supported |
| SPDM versions can be changed if support for other versions is not necessary. |
| |
| ## Responders |
| |
| OpenPRoT devices implementing an SPDM responder must implement support for SPDM |
| 1.2 or higher. Responders may only report (via `GET_VERSION`) a single supported |
| version of SPDM. |
| |
| ## Required Commands |
| |
| All requesters and responders shall implement the four (4) *spec mandatory* SPDM |
| commands: |
| |
| * `GET_VERSION` |
| * `GET_CAPABILITIES` |
| * `NEGOTIATE_ALGORITHMS` |
| * `RESPOND_IF_READY` |
| |
| All requesters and responders shall implement the following *spec optional* |
| commands: |
| |
| * `GET_DIGESTS` |
| * `GET_CERTIFICATE` |
| * `CHALLENGE` |
| * `GET_MEASUREMENTS` |
| * `GET_CSR` |
| * `SET_CERTIFICATE` |
| * `CHUNK_SEND` |
| * `CHUNK_GET` |
| |
| Requesters and responders may implement the following recommended *spec |
| optional* commands: |
| |
| * Events |
| * `GET_SUPPORTED_EVENT_TYPES` |
| * `SUBSCRIBE_EVENT_TYPES` |
| * `SEND_EVENT` |
| * Encapsulated requests |
| * `GET_ENCAPSULATED_REQUEST` |
| * `DELIVER_ENCAPSULATED_RESPONSE` |
| * `GET_KEY_PAIR_INFO` |
| * `SET_KEY_PAIR_INFO` |
| * `KEY_UPDATE` |
| * `KEY_EXCHANGE` |
| * `FINISH` |
| * `PSK_EXCHANGE` |
| * `PSK_FINISH` |
| |
| All other *spec optional* commands may be implemented as the integrator sees fit |
| for their use case. |
| |
| ## Required Capabilities |
| |
| * `CERT_CAP` (required for `GET_CERTIFICATE`) |
| * `CHAL_CAP` (required for `CHALLENGE`) |
| * `MEAS_CAP` (required for `GET_MEASUREMENT`) |
| * `MEAS_FRESH_CAP` |
| |
| ## Algorithms |
| |
| The following cryptographic algorithms are accepted for use within OpenPRoT, but |
| may be further constrained by hardware capabilities. At a minimum OpenPRoT |
| hardware must support: |
| |
| * `TPM_ALG_ECDSA_ECC_NIST_P384` |
| * `TPM_ALG_SHA3_384` |
| |
| All others are optional and may be used if supported. |
| |
| * Asymmetric |
| * `TPM_ALG_ECDSA_ECC_NIST_P256` |
| * `TPM_ALG_ECDSA_ECC_NIST_P384` |
| * `EdDSA ed25519` |
| * `EdDSA ed448` |
| * `TPM_ALG_SHA_384` |
| * Hash |
| * `TPM_ALG_SHA_256` |
| * `TPM_ALG_SHA_384` |
| * `TPM_ALG_SHA_512` |
| * `TPM_ALG_SHA3_256` |
| * `TPM_ALG_SHA3_384` |
| * `TPM_ALG_SHA3_512` |
| * AEAD Cipher |
| * `AES-128-GCM` |
| * `AES-256-GCM` |
| * `CHACHA20_POLY1305` |
| |
| ## Attestation Report Format |
| |
| Devices will support either RATS EAT (as CWT) or an SPDM evidence manifest TOC |
| per the *TCG DICE Concise Evidence for SPDM* specification. |
| |
| ## Measurement block 0xF0 |
| |
| Devices that do not provide a Measurement Manifest shall locate RATS EAT at SPDM |
| measurement block 0xF0 |
