PkCtx double free fix

[stenslae]

Issue #375 -- Reordered each setter to build the new internCtx fully, install it via wolfSSL_Set*Ctx(), and only then free the old one. Deduplicated the six setters and the freeSSL cleanup blocks into two helpers, setPkCtxHelper() and freePkCtx().

[wolfSSL-Fenrir-bot]

Fenrir Automated Review — PR #377

Scan targets checked: wolfssljni-bugs, wolfssljni-src

No new issues found in the changed files. ✅

[Copilot]

Pull request overview

This PR addresses Issue #375 by eliminating a double-free / dangling-pointer hazard in the public-key callback context setters for WolfSSLSession by swapping in a fully-initialized replacement context before freeing the prior one.

Changes:

• Introduces setPkCtxHelper() to atomically replace PK callback internCtx pointers (install new first, then free old).
• Introduces freePkCtx() and refactors freeSSL() PK-context cleanup to use it.
• Ensures NewGlobalRef() failure paths free the newly-allocated (but uninstalled) internCtx.

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[wolfSSL-Fenrir-bot]

Fenrir Automated Review — PR #377

Scan targets checked: wolfssljni-bugs, wolfssljni-src

No new issues found in the changed files. ✅

[cconlon]

@stenslae please rebase on master, which should pick up the fix needed for the Android Gradle test to pass, thanks.