[kojo1]

Description

Wipe and free previous EVP_PKEY DER cache on reassignment.

Fixes F-8331

Testing

Added test_wolfSSL_EVP_PKEY_reassign_der_cache.

Checklist

• [ x] added tests
• updated/added doxygen
• updated appropriate READMEs
• Updated manual and documentation

[Copilot]

🟡 Changes recommended

The reassignment test checks only replacement-cache sizes, so it can still pass when outgoing DSA/DH buffers are not wiped or freed, leaving the intended regression undetected.

1 open issue

• Test that outgoing cache buffers are wiped and freed exactly once · New

What changed in this PR

This PR addresses F-8331 by clearing previous DER key caches during reassignment in wolfSSL’s OpenSSL compatibility layer.

Changes:

• Wipe and free cached DER data and reset cache metadata before DSA, DH, and RSA reassignment.
• Clear temporary DER buffers before release on affected paths.
• Add and register a regression test covering repeated and cross-key-type reassignment.

File	Description
wolfcrypt/​src/​evp.c	Adds DER cache cleanup and temporary-buffer wiping.
tests/​api/​test_evp_pkey.h	Declares and registers the reassignment test.
tests/​api/​test_evp_pkey.c	Adds reassignment checks for DSA, RSA, and DH caches.

_{Review effort: Balanced}

[github-actions]

MemBrowse Memory Report · Explore what changed →

gcc-arm-cortex-m4-openssl-compat

• FLASH: .text +64 B (+0.0%, 797,244 B / 1,048,576 B, total: 76% used)

zephyr-frdm_rw612

• FLASH: text -8 B (-0.0%, 284,016 B / 67,108,864 B, total: 0% used)

No memory changes detected for:

• gcc-arm-cortex-m0plus
• gcc-arm-cortex-m3
• gcc-arm-cortex-m4
• gcc-arm-cortex-m4-baremetal
• gcc-arm-cortex-m4-crypto-only
• gcc-arm-cortex-m4-dtls13
• gcc-arm-cortex-m4-min-ecc
• gcc-arm-cortex-m4-pkcs7
• gcc-arm-cortex-m4-pq
• gcc-arm-cortex-m4-rsa-only
• gcc-arm-cortex-m4-sp-math
• gcc-arm-cortex-m4-tls12
• gcc-arm-cortex-m4-tls13
• gcc-arm-cortex-m7
• gcc-arm-cortex-m7-pq
• gcc-arm-cortex-m7-tls13
• stm32-sim-stm32h753

---

_{Catch memory regressions in CI with MemBrowse. Free for open source.}