[stenslae]

Description

With ALT_ECC_SIZE, alt_fp_ints hold fewer digits than sizeof(a->dp), so the check ran into the next integer and aborted on wiped memory.

They now use a->size, the same length fp_forcezero() wipes, and skip NULL integers. A NULL integer happens with ATECC/TA100 builds, where key->k is left unset.

Adds a fastmath-alt-ecc-check-mem-zero CI entry; this build aborts on master and passes with the fix.

Checklist

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

[Copilot]

🟢 Approval recommended

No active review issues are recorded for the ECC memory-zero check changes.

No open issues 🎉

What changed in this PR

This PR fixes fast-math memory-zero checks for smaller ECC integers, preventing checks from extending beyond their digit storage and triggering false aborts.

Changes:

• Use the initialized digit count for memory-zero checks when ALT_ECC_SIZE or HAVE_WOLF_BIGINT is enabled.
• Skip NULL integers in memory-zero registration and checks.
• Add a Linux CI configuration combining fast math, alternate ECC sizing, and memory-zero checks.

File	Description
wolfcrypt/​src/​tfm.c	Match check lengths to integer storage and guard against NULL integers.
.github/​configs/​os-check-linux.json	Add CI coverage for fast math with alternate ECC sizing and memory-zero checks.

_{Review effort: Balanced}

[github-actions]

MemBrowse Memory Report · Explore what changed →

zephyr-frdm_rw612

• FLASH: log_const_area -8 B, rodata -8 B, text +1,664 B (+0.6%, 284,112 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-openssl-compat
• 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.}

[wolfSSL-Fenrir-bot]

Fenrir Automated Review — PR #12068

Scan targets checked: wolfcrypt-src, wolfcrypt-bugs
Not reviewed (no scan target covers them): .github/configs/os-check-linux.json
Coverage: 1 of 1 in-scope changed file(s) opened by the reviewer

Fenrir result: Approved ✅

No new issues found in the changed files.

Advisory only — this automated result does not count as a GitHub approval.

Review tier: Max