wolfTPM SPDM support (tested with Nuvoton NPCT75x) by aidangarske · Pull Request #458 · wolfSSL/wolfTPM

aidangarske · 2026-02-20T18:32:09Z

Description

Migrates the standalone wolfSPDM library into wolfTPM as an in-tree spdm/
subdirectory and adds full SPDM support for both Nuvoton NPCT75x and
Nations NS350 TPMs. Eliminates the external dependency — a single
--enable-spdm configure flag builds everything.

wolfSPDM Library (spdm/)

SPDM 1.3 (DSP0274) with Algorithm Set B (P-384, SHA-384, AES-256-GCM, HKDF)
Standard mode: works with libspdm spdm-emu responder for testing
TCG SPDM Binding: vendor-defined commands (GET_PUBK, GIVE_PUB, SPDMONLY,
GET_STS_, TPM2_CMD, PSK_SET_, PSK_CLR_)
Identity key session: GET_VERSION, GET_CAPABILITIES, NEGOTIATE_ALGORITHMS,
GET_PUBK, KEY_EXCHANGE, GIVE_PUB, FINISH
PSK session: GET_VERSION, GET_CAPABILITIES, NEGOTIATE_ALGORITHMS,
PSK_EXCHANGE, PSK_FINISH
Secured messaging: AES-256-GCM AEAD with sequence number tracking
Static memory mode (zero-malloc) and dynamic mode (--enable-spdm-dynamic-mem)
Unit test suite (spdm/test/unit_test.c)

Nuvoton NPCT75x Support

NTC2_PreConfig vendor commands for SPDM enable/disable
SPDM-only mode: lock/unlock enforcement over identity key sessions
Auto-SPDM: transparent session establishment when TPM is in SPDM-only mode
Tested: 6/6 hardware tests (status, connect, lock, unit test, unlock, caps)

Nations NS350 Support

PSK Mode

PSK_SET/PSK_CLEAR vendor commands with 32-byte ClearAuth (TCG PC Client spec)
PSK_EXCHANGE/PSK_FINISH session establishment (Salt_0 = 0xFF for PSK mode)
GET_STATUS with response parsing (PSKSet, SPDMOnly, spec version)
SPDM_ONLY lock/unlock for PSK mode
Tested: 10/10 PSK lifecycle tests (provision, connect, clear, re-provision)

Identity Key Mode

Shared TCG SPDM binding protocol with Nuvoton
TPM2_VendorSpdmIdentityKeySet for identity key provisioning
TODO: Re-test on firmware 0.1.0.15 (digest changed to SHA-384(TPMT_PUBLIC))

wolfTPM Integration

13+ new wolfTPM2_Spdm*() wrapper API functions in tpm2_wrap.h
Transparent SPDM transport in TPM2_SendCommand() — all TPM commands
automatically encrypted when SPDM session is active
TIS I/O callback for routing SPDM through SPI/I2C TPM FIFO
Auto-generated ephemeral P-384 key pair for mutual authentication

SPDM Demo (examples/spdm/)

spdm_demo.c: Nuvoton and Nations hardware modes
spdm_test.sh: Automated tests for nuvoton, nations, and nations-psk modes

TCG SPDM Vendor Commands

VdCode	Command	Nuvoton	Nations
GET_PUBK	Get Public Key	Yes	TODO
GIVE_PUB	Give Public Key	Yes	TODO
TPM2_CMD	TPM Command	Yes	Yes
GET_STS_	Get Status	Yes	Yes
SPDMONLY	SPDM-Only Mode	Yes	Yes
PSK_SET_	PSK Set	N/A	Yes
PSK_CLR_	PSK Clear	N/A	Yes

Test Plan

Build with --enable-spdm --enable-nuvoton
Build with --enable-spdm --enable-nations
Build without --enable-spdm (no breakage)
26/26 unit tests PASS
6/6 Nuvoton hardware tests PASS
10/12 Nations PSK hardware tests PASS. (two still need testing)
Nations identity key mode on firmware 0.1.0.15
Copilot review

spdm/src/spdm_context.c

examples/spdm/README.md

.github/workflows/spdm-emu-test.yml

wolftpm/tpm2_wrap.h

dgarske

This is very nice and almost ready for merge. I provided you some feedback directly and I know you are out Monday, so no rush.

- 18/18 emulator tests PASS (6 tests x 3 versions: 1.2, 1.3, 1.4) 1. Removed OpaqueDataLength(2) from CHALLENGE request for SPDM 1.3+ — spec says only RequesterContext(8), no OpaqueDataLength in request 2. Removed OpaqueDataLength(2) from signed GET_MEASUREMENTS request for SPDM 1.3+ — same issue - spdm/README.md: Added supported versions table (spdm-emu: 1.2/1.3/1.4, Nuvoton: 1.3), updated protocol flow diagram, added --ver flag to demo options, added wolfSPDM_SetMaxVersion() to API table, updated emulator section to mention 18-test multi-version coverage - Addressed PR review feedback

dgarske

Please work on code size reduction (possibly moving the spdm-emu stuff to another report). Also please work on the TPM SPDM PSK use case.

Copilot

Pull request overview

Copilot reviewed 38 out of 39 changed files in this pull request and generated 4 comments.

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spdm/src/spdm_context.c

src/tpm2_wrap.c

wolftpm/tpm2.h

wolftpm/tpm2_spdm.h

… lines) Security fixes: - Mandatory responder signature verification in KEY_EXCHANGE_RSP (was conditional skip) - Sensitive stack buffer zeroing (wc_ForceZero) in BuildFinish, ParseKeyExchangeRsp, wolfSPDM_Finish for keys, HMAC, and signature data - TCG integer underflow guard in ParseTcgClearMessage (msgSize < header check) - BuildIV: removed dead code duplicate branches, collapsed to single 8-byte XOR path Code quality: - Cascade error handling (rc == WOLFSPDM_SUCCESS pattern) across spdm_msg.c, spdm_session.c, spdm_secured.c for single-cleanup-path safety - wolfSPDM_BuildVendorDefined: added spdmVersion parameter (was hardcoded 0x13) - spdm_error.h: added spdm_types.h include for standalone WOLFSPDM_API definition - spdm.h: added stack usage documentation (~22KB context, ~20KB call chain) Codebase reduction (-4,301 net lines): - Condensed spdm_demo.c (382->256 lines), spdm_test.sh (143->70 lines) - Removed verbose banner comments and redundant section headers across all files - Consolidated unit tests with shared helpers, removed duplicate test patterns - Removed spdm-emu-test.yml CI workflow (moved to standalone wolfSPDM repo) - Streamlined README documentation Test results: - 26/26 unit tests PASS - 6/6 Nuvoton hardware tests PASS (spdm_test.sh)

- Nations NS350 PSK mode: PSK_SET, PSK_CLEAR, PSK_EXCHANGE, PSK_FINISH, GET_STATUS, SPDM_ONLY with 32-byte ClearAuth per TCG PC Client spec - Salt_0 = 0xFF for PSK mode HKDF-Extract (vs 0x00 for identity key mode) - NATIONS_PSK mode checks in spdm_secured.c encrypt/decrypt paths - GET_STATUS response parsing fix (PSKSet byte was not being read) - Demo cleanup order: TPM2_Shutdown before SPDM disconnect - 32-byte ClearAuth enforcement on PSK_SET and PSK_CLEAR - spdm_test.sh nations-psk: 12-step PSK lifecycle test with NSING reference data - spdm/README.md: TCG commands section, Nations PSK docs, validation status - Removed unused inline PSK_SET, SetPskSetPayload, ConnectNationsPskProvision - SPDM 1.3+ OpaqueDataLength fix for CHALLENGE and GET_MEASUREMENTS requests Tested: 10/10 Nations PSK tests PASS, 6/6 Nuvoton tests PASS

wolfSSL-Fenrir-bot

Fenrir Automated Review — PR #458

Scan targets checked: wolftpm-bugs, wolftpm-src
Findings: 1

Info (1)

Incomplete review: src/*.c diffs truncated

File: hal/tpm_io_linux.c:85-87
Function: N/A
Category: HAL implementation flaws

The diff provided was truncated before reaching the in-scope src/tpm2.c, src/tpm2_packet.c, src/tpm2_spdm.c, src/tpm2_swtpm.c, and src/tpm2_wrap.c changes. The only visible in-scope change is in hal/tpm_io_linux.c which adds a compile-time SPI chip-select constant TPM2_SPI_DEV_CS "0" for WOLFTPM_NATIONS, identical to the existing Nuvoton configuration. This change is benign. The out-of-scope spdm/src/ library code (visible in the diff) demonstrates good security practices: wc_ForceZero for key material, wc_ecc_check_key for peer key validation, proper buffer bounds checking, and state machine enforcement. A complete review of src/tpm2_spdm.c and src/tpm2_wrap.c is recommended as these files contain the integration layer between wolfTPM and the SPDM subsystem.

#elif defined(WOLFTPM_NATIONS)
    /* Nations Technology NS350 uses CE0 */
    #define TPM2_SPI_DEV_CS "0"

Recommendation: Re-run this security review with the complete diff (including src/tpm2.c, src/tpm2_packet.c, src/tpm2_spdm.c, src/tpm2_swtpm.c, and src/tpm2_wrap.c) to ensure full coverage of the in-scope files.

This review was generated automatically by Fenrir. Findings are non-blocking.

Copilot

Pull request overview

Copilot reviewed 41 out of 42 changed files in this pull request and generated 2 comments.

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Copilot · 2026-03-20T20:36:24Z

src/tpm2.c

+    if (rc < 0) /* SPDM not active, use normal transport */
+#endif
+    {
+        rc = (TPM_RC)INTERNAL_SEND_COMMAND(ctx, packet);
+    }


In TPM2_SendCommandAuth(), the SPDM fallback condition uses if (rc < 0) to decide that SPDM is inactive. However, wolfTPM2_SPDM_SecuredExchange/wolfSPDM return negative error codes on real failures (e.g., decrypt/HMAC/IO errors), so this will incorrectly fall back to sending the same command over the clear transport after an SPDM failure. Use a dedicated sentinel for "SPDM not active" (e.g., return -1 only for that case and check rc == -1 here), and treat any other non-zero as a hard error (no cleartext retry).

Suggested change

if (rc < 0) /* SPDM not active, use normal transport */

#endif

{

rc = (TPM_RC)INTERNAL_SEND_COMMAND(ctx, packet);

}

if (rc == -1) { /* SPDM not active, use normal transport */

rc = (TPM_RC)INTERNAL_SEND_COMMAND(ctx, packet);

}

else if (rc != 0) {

/* SPDM is active but the secured exchange failed: do not retry in clear */

return rc;

}

#else

rc = (TPM_RC)INTERNAL_SEND_COMMAND(ctx, packet);

#endif

Copilot · 2026-03-20T20:36:24Z

src/tpm2.c

+#ifdef WOLFTPM_SPDM
+    rc = TPM2_SPDM_SendCommand(ctx, packet);
+    if (rc == TPM_RC_SUCCESS)
+        return TPM2_Packet_Parse(rc, packet);
+    /* rc < 0 means SPDM not active, fall through to normal transport */
+#endif
+
    /* submit command and wait for response */
    rc = (TPM_RC)INTERNAL_SEND_COMMAND(ctx, packet);


In TPM2_SendCommand(), if TPM2_SPDM_SendCommand() returns an SPDM error (non-zero), the code currently falls through to INTERNAL_SEND_COMMAND and will resend the command in cleartext. This can leak commands/authorization after an SPDM failure and can also cause duplicate execution. Handle SPDM outcomes explicitly: return immediately on any error that is not the "SPDM not active" sentinel, and only fall back to INTERNAL_SEND_COMMAND when SPDM is not configured/connected.

aidangarske self-assigned this Feb 20, 2026

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aidangarske mentioned this pull request Feb 20, 2026

Add TPM2.0 SPDM Support with Nuvoton NPCT75x / spdm-emu #453

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Add full SPDM nuvoton and spdm-emu support as wolfTPM/spdm

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aidangarske force-pushed the add-full-spdm-support branch from b684e06 to e56719c Compare February 26, 2026 18:25

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aidangarske changed the title ~~wolfSPDM migration to wolfTPM/spdm with Nuvoton and spdm-emu support~~ wolfSPDM migration to wolfTPM/spdm with Nuvoton NPCT75x Mar 13, 2026

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dgarske changed the title ~~wolfSPDM migration to wolfTPM/spdm with Nuvoton NPCT75x~~ wolfTPM SPDM support (tested with Nuvoton NPCT75x) Mar 18, 2026

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aidangarske commented Feb 20, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Description

wolfSPDM Library (spdm/)

Nuvoton NPCT75x Support

Nations NS350 Support

PSK Mode

Identity Key Mode

wolfTPM Integration

SPDM Demo (examples/spdm/)

TCG SPDM Vendor Commands

Test Plan

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Pull request overview

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Fenrir Automated Review — PR #458

Info (1)

Incomplete review: src/*.c diffs truncated

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aidangarske commented Feb 20, 2026 •

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