§H.12 step 18: zuse_eligibility.c -- read/add/membership-check

is_member() (fail-closed) and add() (idempotent, chains new devblocks onto the tail as needed) over the item-17 eligibility-list devblock chain, mirroring capsule_zuse_boot.c's magic/version/CRC-64 validation convention. No callers yet. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01QgooKd5hJNtTYqB6CyK5f9
2026-09-03 11:24:24 -04:00
parent 21ad5f7373
commit f4615cf605
13 changed files with 45969 additions and 2 deletions
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+/*
+  StarForth — Steady-State Virtual Machine Runtime
+
+  Copyright (c) 2023–2025 Robert A. James
+  All rights reserved.
+
+  Licensed under the StarForth License, Version 1.0
+*/
+
+/**
+ * zuse_eligibility.h - Read/add/membership-check over the on-disk
+ * elevation eligibility list (FABRIC-3.md §H.5/§H.12 Phase 6,
+ * zuse_eligibility_list.h's zuse_eligibility_devblock_t chain). Zuse
+ * checks zuse_eligibility_is_member() before honoring any
+ * ELEVATE-REQUEST (§H.7/§H.8) -- a gating layer on top of the
+ * message-based elevation trigger, not a replacement for it. Adding an
+ * entry (zuse_eligibility_add()) is meant to be reachable only from a
+ * Zuse-only FORTH word (§H.12 item 19, gated by zuse_session), not
+ * called directly from arbitrary session code.
+ */
+
+#ifndef STARKERNEL_ZUSE_ELIGIBILITY_H
+#define STARKERNEL_ZUSE_ELIGIBILITY_H
+
+#ifdef __STARKERNEL__
+
+#include <stdint.h>
+
+/**
+ * zuse_eligibility_is_member - Check whether pubkey appears anywhere in
+ * the eligibility list chain. Fail-closed: an empty/nonexistent list, a
+ * corrupt/foreign devblock encountered mid-chain, or any I/O error all
+ * read as "not eligible" (0), never "eligible" -- this gates elevation,
+ * so an unreadable list must never be treated as permissive.
+ *
+ * @param pubkey  32-byte Ed25519 public key to look up.
+ * @return        1 if found, 0 otherwise (including on any error).
+ */
+int zuse_eligibility_is_member(const uint8_t pubkey[32]);
+
+/**
+ * zuse_eligibility_add - Add pubkey to the eligibility list, creating
+ * the list's head devblock if it doesn't exist yet and chaining a fresh
+ * devblock onto the tail if the current tail is full. Idempotent: adding
+ * an already-present pubkey is a no-op success, not a duplicate entry.
+ *
+ * @param pubkey  32-byte Ed25519 public key to add.
+ * @return        0 on success (added, or already present), -1 on
+ *                failure (fence write failed, fence budget exhausted, or
+ *                a corrupt devblock was encountered mid-chain).
+ */
+int zuse_eligibility_add(const uint8_t pubkey[32]);
+
+#endif /* __STARKERNEL__ */
+
+#endif /* STARKERNEL_ZUSE_ELIGIBILITY_H */