feat: 添加 OpenNexus 认证 Core 与 Stronghold 基础能力

frontend/src-tauri/src/runtime_compat.rs

@@ -0,0 +1,39 @@
+//! C23 compatibility for the MSVCRT-based Windows GNU development target.
+//! Recent libsodium archives reference memset_explicit, absent in MSVCRT.
+//! Volatile stores preserve its non-elidable wipe semantics; MSVC/UCRT release
+//! builds use their native runtime and do not compile this compatibility symbol.
+
+#[cfg(all(windows, target_env = "gnu"))]
+#[no_mangle]
+unsafe extern "C" fn memset_explicit(
+    destination: *mut std::ffi::c_void,
+    value: std::ffi::c_int,
+    count: usize,
+) -> *mut std::ffi::c_void {
+    for offset in 0..count {
+        // SAFETY: the C ABI caller must supply a writable region of count bytes,
+        // exactly as for memset. Volatile stores cannot be removed as dead writes.
+        unsafe {
+            destination
+                .cast::<u8>()
+                .add(offset)
+                .write_volatile(value as u8);
+        }
+    }
+    std::sync::atomic::compiler_fence(std::sync::atomic::Ordering::SeqCst);
+    destination
+}
+
+#[cfg(all(test, windows, target_env = "gnu"))]
+mod tests {
+    #[test]
+    fn explicit_memset_preserves_surrounding_bytes_and_return_pointer() {
+        let mut data = [0x55u8; 34];
+        let pointer = data[1..33].as_mut_ptr().cast();
+        // SAFETY: the subslice contains exactly 32 writable bytes.
+        assert_eq!(unsafe { super::memset_explicit(pointer, 0, 32) }, pointer);
+        assert_eq!(data[0], 0x55);
+        assert_eq!(data[33], 0x55);
+        assert!(data[1..33].iter().all(|b| *b == 0));
+    }
+}