Zero-copy FFI optimization (v0.3.3)

CHANGELOG.md

@@ -5,13 +5,28 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## Unreleased
+## v0.3.3 - 2026-03-27
 
 ### Added
 
+- Zero-copy vault reads via `memmap2` memory-mapped I/O — `vault_read` and `vault_read_stream` now slice directly into mapped file pages instead of allocating heap buffers with `read_exact`.
+- `VaultMmap` wrapper with `mlock()` on unix to pin ciphertext pages in RAM and prevent swap-to-disk. Graceful fallback to heap reads when mmap fails (32-bit targets, low `mlock` limits).
+- mmap invalidation/recreation after every vault mutation (write, delete, defrag, resize).
+- ELF linker version script (`ffi-exports.map`) restricting Android/Linux `.so` dynamic symbol table to FRB FFI symbols only — hides `#[no_mangle]` symbols leaked by dependencies.
+- `build.rs` for conditional version script application on Android/Linux cdylib builds.
+
 ### Changed
 
-### Fixed
+- Switched all 50 FRB functions from SSE to CST+DCO codec via `full_dep: true` — `Vec<u8>` returns now use `allo-isolate` `ExternalTypedData` (pointer transfer, no memcpy) instead of SSE serialization.
+- Release profile hardened: `lto = "fat"`, `codegen-units = 1`, `strip = "symbols"`, `opt-level = 3`.
+- `VaultHandle` field order: `mmap` before `file` so `munlock`/`munmap` runs while the fd is still open.
+
+### Security
+
+- Symbol stripping removes internal Rust function names from release binaries — `nm -D` shows only FRB entry points and libc on ELF targets.
+- `mlock()` prevents OS from swapping mmap'd ciphertext pages to disk swap.
+- Fewer intermediate `Vec<u8>` copies means shorter plaintext residency in memory.
+- ZeroizeOnDrop behavior preserved — no regression from zero-copy refactoring.
 
 ## [v0.3.2](https://github.com/MicroClub-USTHB/M-Security/releases/tag/v0.3.2) - 2026-03-26
 

README.md

@@ -29,6 +29,7 @@ Built and maintained by the **Dev Department** of [MicroClub](https://github.com
 | **Password Hashing**     | Argon2id               | PHC winner, Mobile and Desktop presets                      |
 | **Key Derivation**       | HKDF-SHA256            | RFC 5869, extract-then-expand with domain separation        |
 | **Encrypted VFS (EVFS)** | `.vault` container     | Named segments, WAL recovery, shadow index, secure deletion |
+| **Zero-Copy I/O**        | mmap + DCO codec       | Memory-mapped vault reads, zero-copy Rust-to-Dart transfers |
 
 **Security by design:**
 
@@ -38,14 +39,16 @@ Built and maintained by the **Dev Department** of [MicroClub](https://github.com
 - AEAD tag verification prevents silent decryption of tampered data
 - `panic = "abort"` in release profile, preventing undefined behavior from panics crossing FFI
 - `clippy::unwrap_used = "deny"`, ensuring all operations return `Result<T, CryptoError>`
+- Release builds strip all symbols except FRB entry points (LTO + ELF version script)
+- `mlock()` pins mmap'd ciphertext pages to prevent swap-to-disk (unix)
 
 ## Installation
 
 Add to your `pubspec.yaml`:
 
 ```yaml
 dependencies:
-  m_security: ^0.3.2
+  m_security: ^0.3.3
 ```
 
 Then run:
@@ -329,13 +332,13 @@ hkdf_expand(prk, info, output_len)          -> Result<Vec<u8>>
 
 ## Testing
 
-**Rust unit tests** (317 tests including EVFS streaming and defrag):
+**Rust unit tests** (331 tests including EVFS streaming and defrag):
 
 ```bash
 cd rust && cargo test
 ```
 
-**Dart integration tests** (63 tests across all features, requires a running device/simulator):
+**Dart integration tests** (76 tests across all features, requires a running device/simulator):
 
 ```bash
 cd example
@@ -351,7 +354,7 @@ flutter test integration_test/
 | Dart SDK            | ^3.10.8 |
 | Flutter SDK         | >=3.3.0 |
 
-**Rust crates:** `aes-gcm` 0.10, `chacha20poly1305` 0.10, `blake3` 1.8, `sha3` 0.10, `argon2` 0.5, `hkdf` 0.12, `zstd` 0.13, `brotli` 7.0, `zeroize` 1.8
+**Rust crates:** `aes-gcm` 0.10, `chacha20poly1305` 0.10, `blake3` 1.8, `sha3` 0.10, `argon2` 0.5, `hkdf` 0.12, `zstd` 0.13, `brotli` 7.0, `zeroize` 1.8, `memmap2` 0.9
 
 ## Roadmap
 
@@ -362,6 +365,7 @@ flutter test integration_test/
 | **Encrypted Virtual File System (EVFS)** | `.vault` container with named segments, WAL recovery, shadow index, secure deletion | v0.3.0  |
 | **EVFS v2: Defrag & resize**             | Online defragmentation, vault resizing, health diagnostics                          | v0.3.1  |
 | **EVFS v3: Streaming I/O**                | Constant-memory streaming reads/writes, per-chunk AEAD, progress callbacks          | v0.3.2  |
+| **Zero-copy FFI optimization**           | mmap vault reads, DCO codec, release profile hardening, symbol stripping            | v0.3.3  |
 | **EVFS v2: Key rotation**                | Re-encrypt vault with new master key                                                | Planned |
 | **Stealth storage**                      | Ephemeral secrets in Rust-managed memory with derived-path obfuscation              | Planned |
 | **Hardware key wrap**                    | Master key in Secure Enclave (iOS) / KeyStore (Android) with biometric unlock       | Planned |

flutter_rust_bridge.yaml

@@ -2,5 +2,6 @@ rust_input: crate::api
 rust_root: rust/
 dart_output: lib/src/rust
 enable_lifetime: true
+full_dep: true
 rust_features:
   - compression

lib/src/rust/api/encryption.dart

@@ -64,5 +64,5 @@ Future<String> encryptionAlgorithmId({required CipherHandle cipher}) => RustLib
     .api
     .crateApiEncryptionEncryptionAlgorithmId(cipher: cipher);
 
-// Rust type: RustOpaqueMoi<flutter_rust_bridge::for_generated::RustAutoOpaqueInner<CipherHandle>>
+// Rust type: RustOpaqueNom<flutter_rust_bridge::for_generated::RustAutoOpaqueInner<CipherHandle>>
 abstract class CipherHandle implements RustOpaqueInterface {}

lib/src/rust/api/evfs/types.dart

@@ -6,9 +6,11 @@
 import '../../frb_generated.dart';
 import 'package:flutter_rust_bridge/flutter_rust_bridge_for_generated.dart';
 
-// These function are ignored because they are on traits that is not defined in current crate (put an empty `#[frb]` on it to unignore): `clone`, `eq`, `fmt`
+// These functions are ignored because they are not marked as `pub`: `new`, `refresh_mmap`, `slice`
+// These types are ignored because they are neither used by any `pub` functions nor (for structs and enums) marked `#[frb(unignore)]`: `VaultMmap`
+// These function are ignored because they are on traits that is not defined in current crate (put an empty `#[frb]` on it to unignore): `clone`, `drop`, `eq`, `fmt`
 
-// Rust type: RustOpaqueMoi<flutter_rust_bridge::for_generated::RustAutoOpaqueInner<VaultHandle>>
+// Rust type: RustOpaqueNom<flutter_rust_bridge::for_generated::RustAutoOpaqueInner<VaultHandle>>
 abstract class VaultHandle implements RustOpaqueInterface {
   /// Compute health information from the in-memory index only (no file I/O or WAL writes).
   Future<VaultHealthInfo> health();

lib/src/rust/api/hashing.dart

@@ -50,5 +50,5 @@ Future<Uint8List> blake3Hash({required List<int> data}) =>
 Future<Uint8List> sha3Hash({required List<int> data}) =>
     RustLib.instance.api.crateApiHashingSha3Hash(data: data);
 
-// Rust type: RustOpaqueMoi<flutter_rust_bridge::for_generated::RustAutoOpaqueInner<HasherHandle>>
+// Rust type: RustOpaqueNom<flutter_rust_bridge::for_generated::RustAutoOpaqueInner<HasherHandle>>
 abstract class HasherHandle implements RustOpaqueInterface {}