Restore ECC salted sessions and key import without ECC_TIMING_RESISTANT

[dgarske]

Description

Regression in v4.2.0. Broken by #582 (items 1 and 2), #597 (item 3). ZD 22550

A wolfSSL build without ECC_TIMING_RESISTANT (a user_settings.h build that omits it, or --disable-harden) gets NOT_COMPILED_IN from three ECC paths in src/tpm2_wrap.c that worked in v4.1.0. Reported by a customer as wolfTPM2_StartSession failing while building the encrypted salt.

1. ECC salted sessions and import seeds

wolfTPM2_EncryptSecret_ECC() and the TPM_ALG_ECC case in wolfTPM2_EncryptSecret() were compiled out without the macro, so a session salted with an ECC key, or an import under an ECC parent, returned NOT_COMPILED_IN. The guard is back to HAVE_ECC, !WC_NO_RNG and WOLFSSL_PUBLIC_MP. The RNG is still attached to both keys when timing resistance is available.

2. Private-only ECC key import

wolfTPM2_EccMakePubBlinded() returned NOT_COMPILED_IN without the macro. It now falls back to wc_ecc_make_pub(). The blinded wc_ecc_make_pub_ex() path is unchanged in hardened builds.

3. SPDM requester key auto-generation

wolfTPM2_SpdmConnectNuvoton() and wolfTPM2_SpdmConnectNations() returned NOT_COMPILED_IN when no requester key was supplied. The ephemeral P-384 key generation is enabled for any HAVE_ECC build again.
Whether wolfCrypt's ECC is timing resistant is a wolfSSL build choice, and wolfSSL already warns at build time when it is off. wolfTPM should not turn that choice into a runtime failure.

Testing

Adds an ECC case to test_wolfTPM2_EncryptSecret, a private-only import test for wolfTPM2_CreateEccKeyBlob, and a no-harden CI job that builds wolfSSL with --disable-harden and runs make check and run_examples.sh. Run against wolfSSL 5.9.4 built with and without --disable-harden, on the fwTPM and on ibmswtpm2. The SPDM paths are compile-tested only.

[Copilot]

Copilot review overview

🟡 Changes recommended

The no-harden CI job does not compile either changed vendor SPDM path.

Review effort: Balanced
Findings: 1

Open (1)

• Add no-harden compile variants for vendor SPDM configurations · New

What changed in this PR

Restores ECC operations in wolfSSL builds without ECC_TIMING_RESISTANT.

Changes:

• Re-enables ECC secret encryption and unblinded private-key public derivation.
• Re-enables SPDM requester key generation.
• Adds regression tests and no-harden CI coverage.

File	Description
src/​tpm2_wrap.c	Restores non-hardened ECC paths.
tests/​unit_tests.c	Tests ECC secret encryption and private-only imports.
.github/​workflows/​make-test-swtpm.yml	Adds no-harden testing.

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