Fix potential overflows in used size calculation in generic, TI and SE050 hash functions.

[kareem-wolfssl]

Description

Fixes #9951.

Thanks to Arjuna Arya for the report.

Testing

Built in tests

Checklist

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

[Copilot]

Pull request overview

Prevents se050_hash_update from proceeding when se050Ctx->used + len would overflow, addressing the reported issue in #9951.

Changes:

• Introduces a safe-add check (WC_SAFE_SUM_WORD32) before updating the hash state.
• Adds a tmpSz accumulator to hold the checked sum of used + len.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

You can also share your feedback on Copilot code review. Take the survey.

[Copilot]

The overflow case (!WC_SAFE_SUM_WORD32(...)) is currently mapped to BAD_FUNC_ARG, which is also used for null-pointer arguments. Consider returning a more specific error code for an invalid/too-large length (e.g., the project’s standard buffer/length error), so callers can distinguish programming errors from input-size issues.

Suggested change

	if (se050Ctx == NULL || (len > 0 && data == NULL) ||
	!WC_SAFE_SUM_WORD32(se050Ctx->used, len, tmpSz)) {
	return BAD_FUNC_ARG;
	}
	if (se050Ctx == NULL || (len > 0 && data == NULL)) {
	return BAD_FUNC_ARG;
	}
	if (!WC_SAFE_SUM_WORD32(se050Ctx->used, len, tmpSz)) {
	return LENGTH_ERROR;
	}

[Copilot]

This if condition now mixes argument validation and arithmetic overflow handling, which makes it harder to read and extend. Consider splitting it into sequential early-return checks (e.g., validate pointers first, then do the safe-sum check) so future changes don’t inadvertently weaken one of the checks.

Suggested change

	if (se050Ctx == NULL || (len > 0 && data == NULL) ||
	!WC_SAFE_SUM_WORD32(se050Ctx->used, len, tmpSz)) {
	return BAD_FUNC_ARG;
	}
	if (se050Ctx == NULL) {
	return BAD_FUNC_ARG;
	}
	if (len > 0 && data == NULL) {
	return BAD_FUNC_ARG;
	}
	if (!WC_SAFE_SUM_WORD32(se050Ctx->used, len, tmpSz)) {
	return BAD_FUNC_ARG;
	}

[kareem-wolfssl]

Retest this please.