SE050: create ECDH derive target object for applet 7.2 middleware by LinuxJedi · Pull Request #10971 · wolfSSL/wolfssl

LinuxJedi · 2026-07-22T16:42:44Z

Middleware built for SE05x applet >= 07_02 (required for SE052) derives the ECDH shared secret with Se05x_API_ECDHGenerateSharedSecret_InObject, which requires TLV[TAG_7] to reference an existing HMACKey object sized exactly to the shared secret; otherwise the applet returns SW 0x6985 (conditions not satisfied). The port never created this object, so ECDH offload failed with WC_HW_E on such builds.

Create the derive target as an HMACKey object of the exact secret size before the derive, for both ECC and Curve25519 shared secrets. Read the result back as AES type since sss_se05x_key_store_get_key has no HMAC read case.

Fixes zd#22069

Testing

wolfSSL/simulators#9

Middleware built for SE05x applet >= 07_02 (required for SE052) derives the ECDH shared secret with Se05x_API_ECDHGenerateSharedSecret_InObject, which requires TLV[TAG_7] to reference an existing HMACKey object sized exactly to the shared secret; otherwise the applet returns SW 0x6985 (conditions not satisfied). The port never created this object, so ECDH offload failed with WC_HW_E on such builds. Create the derive target as an HMACKey object of the exact secret size before the derive, for both ECC and Curve25519 shared secrets. Read the result back as AES type since sss_se05x_key_store_get_key has no HMAC read case.

Copilot

Pull request overview

Fixes SE050 ECDH offload failures against SE05x applet >= 7.2 middleware by ensuring a correctly-sized derive-target object exists before calling the shared-secret derive APIs.

Changes:

Allocate the ECDH derive target as an HMACKey object (instead of Binary) so applet 7.2+ can store the shared secret into an existing object.
Pre-create the derive-target object with the exact shared-secret size (ECC and Curve25519) prior to derivation.
Read the derived secret back by temporarily treating the object as AES since sss_key_store_get_key() lacks an HMAC read case.

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github-actions · 2026-07-22T17:18:48Z

MemBrowse Memory Report

gcc-arm-cortex-m3

FLASH: .text +72 B (+0.1%, 122,611 B / 262,144 B, total: 47% used)

gcc-arm-cortex-m4

FLASH: .text +64 B (+0.0%, 200,853 B / 262,144 B, total: 77% used)

gcc-arm-cortex-m4-dtls13

FLASH: .text +64 B (+0.0%, 181,092 B / 1,048,576 B, total: 17% used)

gcc-arm-cortex-m4-openssl-compat

FLASH: .rodata +104 B, .text -960 B (-0.1%, 771,028 B / 1,048,576 B, total: 74% used)
RAM: .bss +192 B (+0.1%, 136,936 B / 262,144 B, total: 52% used)

gcc-arm-cortex-m4-pkcs7

FLASH: .text +448 B (+0.2%, 213,844 B / 262,144 B, total: 82% used)

gcc-arm-cortex-m4-rsa-only

FLASH: .text +256 B (+0.1%, 326,168 B / 1,048,576 B, total: 31% used)

gcc-arm-cortex-m4-tls12

FLASH: .text +64 B (+0.1%, 123,355 B / 262,144 B, total: 47% used)

gcc-arm-cortex-m7

FLASH: .text +64 B (+0.0%, 200,853 B / 262,144 B, total: 77% used)

linuxkm-pie

Data: __patchable_function_entries +296 B (+1.1%, 26,256 B)

linuxkm-standard

Data: __patchable_function_entries +368 B (+0.8%, 48,976 B)

stm32-sim-stm32h753

FLASH: .text +1,856 B (+1.0%, 185,684 B / 2,097,152 B, total: 9% used)
No memory changes detected for:
gcc-arm-cortex-m0plus
gcc-arm-cortex-m4-baremetal
gcc-arm-cortex-m4-crypto-only
gcc-arm-cortex-m4-min-ecc
gcc-arm-cortex-m4-pq
gcc-arm-cortex-m4-sp-math
gcc-arm-cortex-m4-tls13
gcc-arm-cortex-m7-pq
gcc-arm-cortex-m7-tls13

Align se050_curve25519_shared_secret with the ECC path: set deriveKeyCreated only after sss_key_store_set_key succeeds, so the cleanup path cannot erase or free a derive key object whose handle was never allocated.

Bump SIMULATORS_REF to the simulator commit that supports HMACKey WriteSymmKey and the applet 7.2 ECDH InObject contract, and run the test container with SE050_SIM_STRICT_ECDH=1 so the simulator refuses an ECDH derive whose Tag7 target object was not pre-created. This is the failure mode seen on SE05x applet >= 7.2 hardware and reproduces it in CI against the unfixed port. The pinned simulator commit also consumes the WOLFSSL_EXTRA_CFLAGS build ARG, so the only-key-id matrix leg now really builds with -DWOLFSSL_SE050_ONLY_KEY_ID (previously the ARG was not consumed and the leg silently built the default configuration), and it fixes the simulator to derive the EC public key on private-only key pair import so wc_ecc_use_key_id can read the public part back. Raise the job timeout for cold image rebuilds until the weekend cron refreshes the registry cache for the new ref.

The previous pin abbreviated to the right commit but the full hash was invalid, so the simulator checkout step could never resolve it. Pin the full commit id of the merged simulator change.

Frauschi

LGTM

LinuxJedi · 2026-07-29T14:56:53Z

Also fixes ZD#22212

Applet 7.2 denies ReadObject on a symmetric key object that was created with no policy attached, so the shared secret written into the derive target by Se05x_API_ECDHGenerateSharedSecret_InObject could not be exported: sss_key_store_get_key failed with SW 0x6986 (command not allowed) on SE05x applet >= 7.2 hardware. Create the derive target with an attached common policy granting read, write and delete. An attached policy replaces the applet default entirely, so write (the ECDH engine storing the result) and delete (the cleanup path) must be granted explicitly alongside read. Guarded by SSS_HAVE_SE05X_VER_GTE_07_02 so builds against older middleware keep creating the object with no policy attached.

Bump SIMULATORS_REF to the simulator commit that, in strict mode, refuses ReadObject on an HMACKey object unless the policy attached at creation grants POLICY_OBJ_ALLOW_READ. This reproduces the SW 0x6986 derive-target readback failure seen on SE05x applet >= 7.2 hardware (ZD 22212) and verifies the attached-policy fix in the previous commit. The pinned commit is wolfSSL/simulators PR wolfSSL#10 and becomes fetchable from the upstream clone once that PR is merged.

LinuxJedi · 2026-07-30T10:06:35Z

Updated PR with some missing policy pieces.

Frauschi

@LinuxJedi PRB-master-job fails, as SSS_HAVE_SE05X_VER_GTE_07_02 is missing from .wolfssl_known_macro_extras. Otherwise LGTM.

LinuxJedi · 2026-07-30T13:06:57Z

I need to do further testing before I'm ready to call this good.

Real SE050 hardware (applet 3.1.1, JCOP4) refuses ReadObject on a symmetric key object created without a read policy just like applet 7.2 does, and pre-7.2 middleware has no way to grant that policy: sss_policy_common_u can_Read maps to POLICY_OBJ_ALLOW_READ only for SSS_HAVE_SE05X_VER_GTE_07_02 builds and the symmetric key policy union has no read flag at all. Switching the derive target to an HMACKey object unconditionally therefore broke ECDH offload on applet 3.x parts with SW 0x6986 at the shared secret export. Restrict the HMACKey target and its attached read policy to SSS_HAVE_SE05X_VER_GTE_07_02 builds and restore the original Binary object flow otherwise: no pre-created target, erase before derive, and the middleware creates the object when storing the derived secret. Binary objects are readable without an attached policy. Verified on SE050C (applet 3.1.1) hardware: the ECC and CURVE25519 wolfCrypt tests fail with SW 0x6986 without this change and pass with it, matching master behavior on the same part. The applet 7.2 path is unchanged.

Bump SIMULATORS_REF to the simulator commit that refuses ReadObject on an HMACKey object without POLICY_OBJ_ALLOW_READ in all modes, matching real hardware on every applet generation as verified on SE050C applet 3.1.1 silicon. With this pin a plain (non-strict) CI run reproduces the SW 0x6986 readback failure that previously only appeared on hardware, covering the pre-7.2 Binary derive target fix in the previous commit. The pinned commit is wolfSSL/simulators PR wolfSSL#11 and becomes fetchable from the upstream clone once that PR is merged.

The SE050 port now keys the ECDH derive target type and read policy off the middleware's SSS_HAVE_SE05X_VER_GTE_07_02 feature macro.

The pinned simulator gained an sdk-test fix and review changes; move SIMULATORS_REF to the final wolfSSL/simulators PR wolfSSL#11 head. Becomes fetchable from the upstream clone once that PR is merged.

Copilot AI review requested due to automatic review settings July 22, 2026 16:42

LinuxJedi mentioned this pull request Jul 22, 2026

SE050Sim: enforce applet 7.2 ECDH InObject target contract wolfSSL/simulators#9

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Copilot started reviewing on behalf of LinuxJedi July 22, 2026 16:53 View session

Copilot AI reviewed Jul 22, 2026

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Comment thread wolfcrypt/src/port/nxp/se050_port.c Outdated

LinuxJedi added 3 commits July 23, 2026 12:07

SE050: only flag curve25519 derive key after it is created

f23da12

Align se050_curve25519_shared_secret with the ECC path: set deriveKeyCreated only after sss_key_store_set_key succeeds, so the cleanup path cannot erase or free a derive key object whose handle was never allocated.

SE050 CI: correct pinned simulator commit id

6d0e149

The previous pin abbreviated to the right commit but the full hash was invalid, so the simulator checkout step could never resolve it. Pin the full commit id of the merged simulator change.

LinuxJedi assigned wolfSSL-Bot Jul 23, 2026

Frauschi previously approved these changes Jul 24, 2026

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LinuxJedi added 2 commits July 30, 2026 10:29

LinuxJedi dismissed Frauschi’s stale review via cc3fd50 July 30, 2026 10:03

Frauschi requested changes Jul 30, 2026

View reviewed changes

LinuxJedi marked this pull request as draft July 30, 2026 12:39

LinuxJedi added 4 commits July 30, 2026 15:50

Add SSS_HAVE_SE05X_VER_GTE_07_02 to known macro extras

e12921d

The SE050 port now keys the ECDH derive target type and read policy off the middleware's SSS_HAVE_SE05X_VER_GTE_07_02 feature macro.

SE050 CI: update pinned simulator to PR 11 head

fea9e1d

The pinned simulator gained an sdk-test fix and review changes; move SIMULATORS_REF to the final wolfSSL/simulators PR wolfSSL#11 head. Becomes fetchable from the upstream clone once that PR is merged.

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SE050: create ECDH derive target object for applet 7.2 middleware - #10971

SE050: create ECDH derive target object for applet 7.2 middleware#10971
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