VaultExplorer

An Android file manager for encrypted containers, drives, and directory vaults — no PC required.

VaultExplorer allows you to mount, browse, create, and manage encrypted volumes directly on your Android device. It supports VeraCrypt, LUKS1 / LUKS2, BitLocker, Cryptomator, gocryptfs, and CryFS volumes, as well as VHD / VHDX disk image files. Built with Flutter and powered by a custom C++ native engine (mbedTLS + FatFs + NTFS-3G + libext2fs + Dislocker), everything is decrypted and re-encrypted on-the-fly in memory with zero unencrypted temporary files written to disk.

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📸 Screenshots

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✨ Features & Architecture

🔐 Supported Formats & Encryption Systems

Block-Level Containers & Disk Images

• VeraCrypt (.hc): Standard & embedded Hidden Volume support, custom PIM, additive keyfiles, and volume password changes.
• LUKS1 & LUKS2: Full support for xts-plain64 volumes. Keyslots backed by PBKDF2 or memory-hard Argon2id / Argon2i. Supports passphrase or keyfile substitution (cryptsetup --key-file).
• BitLocker: Decrypt and re-encrypt BitLocker partitions and BitLocker To Go volumes using user passwords or 48-digit numerical recovery keys (powered by an integrated dislocker backend).
• VHD & VHDX Images: Native Block Allocation Table (BAT) translation for both fixed and dynamic (expandable) virtual hard disk images containing VeraCrypt, LUKS, or BitLocker partitions.

Directory-Based Vaults

• Cryptomator: Supports Vault Format 7 & 8 (cipher combos SIV_GCM and SIV_CTRMAC). Handles masterkey scrypt unwrapping, base32 directory ID hashing, and long-filename shortening (.c9s / name.c9r).
• gocryptfs: Modern default vault format support (GCMIV128, DirIV, EMENames, LongNames, Raw64, HKDF). EME filename encryption and 4KB chunk-level AES-GCM streaming.
• CryFS: Full format support (0.10). Dual-layer scrypt configuration decryption, block sharding storage, Merkle data tree indexing (CryfsDataTree), and directory blob serialization (CryfsDirBlob). Supports xchacha20-poly1305, aes-256-gcm, aes-128-gcm, aes-256-cfb, and aes-128-cfb.

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🗝️ Cryptographic Algorithms & Ciphers

• Block & Stream Ciphers: AES-256, AES-128, Serpent, Twofish, Camellia, Kuznyechik, and XChaCha20-Poly1305.
• Cipher Modes: XTS, GCM, CTR, CFB, EME (filename encryption), and AES-SIV (synthetic IV).
• VeraCrypt Cascades: All 15 single and multi-layer cipher combinations (e.g., AES-Twofish-Serpent, Kuznyechik-Serpent-Camellia, Camellia-Kuznyechik).
• Key Derivation Functions (KDF): PBKDF2 with SHA-512, SHA-256, Whirlpool, Streebog (512-bit), or BLAKE2s-256, alongside Argon2id and scrypt.
• Parallel Auto-Detect Engine: Multi-threaded C++ header derivation testing fast algorithms concurrently before memory-hard Argon2id iterations, with real-time UI progress.

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🚀 Fast Direct Storage Access (POSIX Acceleration)

• POSIX File System Bypass: Folder-based vaults (Cryptomator, gocryptfs, CryFS) can operate using direct POSIX file operations via Android's MANAGE_EXTERNAL_STORAGE permission, bypassing slow Storage Access Framework (SAF) document trees.
• Up to 1000x Speedup: Dramatically improves block reading, writing, and directory listing speeds—especially critical for CryFS vaults containing thousands of small block files.

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💾 Filesystems & USB OTG Integration

• Filesystem Drivers: Native C++ implementations of FAT32, exFAT (via ChaN FatFs), NTFS (via Tuxera NTFS-3G), and ext2 / ext3 / ext4 (via e2fsprogs libext2fs).
• Custom USB OTG Mass Storage Driver: Built-in SCSI Bulk-Only Transport (BOT) driver operating over Android’s USB Host API. No root required. Parses MBR/GPT partition tables and auto-locks volumes on device ejection.
• On-Device Format & Creation: Create and format brand-new VeraCrypt, LUKS1, LUKS2, Cryptomator, gocryptfs, or CryFS containers/vaults directly on internal storage or raw USB flash drives (with Quick Format or Full zero-fill options).
• Multi-Mount Manager: Mount up to 8 active volume slots simultaneously.

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📁 Explorer, Media Streaming & Built-In Password Manager

• File Explorer: Grid, detailed list, and compact view modes with breadcrumb navigation, instant search text highlighting, folder-size calculation, and custom sorting.
• In-Vault ZIP Archive Browser: Directly view and extract .zip archive contents inside an encrypted container without decrypting the archive to host storage.
• Background File Operations: Multi-threaded copy, move, import, and delete engine with LIFO queue prioritisation, pre-flight free-space calculation, conflict resolution sheets, and rollback on disk-full.
• Integrated Media Viewer: On-the-fly streaming for video/audio (FFmpeg-backed fvp engine, .srt/.vtt closed captions, playback speed, double-tap seek, audio visualizers) and images (pinch-to-zoom, 90° rotation, slideshow, gallery carousel) using virtual file handles.
• Encrypted Item Vault: Store logins, payment cards, secure notes, identities, bank accounts, and software licenses directly inside the vault as encrypted native JSON objects.
• Android SAF Provider: Integrates with Android's Storage Access Framework (ContainerDocumentsProvider), allowing third-party apps to securely open and save files inside unlocked containers via AppFuse proxy descriptors.

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🛡️ App Security & Privacy

• Zero Internet Permission: The app does not request or require network access (android.permission.INTERNET is absent).
• Master Lock: App-wide access protection with Master Password, Biometric Unlock (Fingerprint / Face via Android Keystore), or Pattern Lock, backed by exponential lockout backoff surviving app force-kills.
• Hardware-Bound Key Caching: Fast re-unlocks via AES-256-GCM derived key caching stored in the hardware-backed Android Keystore.
• 3-Tier Thumbnail Cache: In-Memory LRU $\rightarrow$ AES-GCM Encrypted Disk/In-Container Cache $\rightarrow$ Native Generation. Can be completely disabled for total privacy.
• Screen & Clipboard Protection: Screenshot/task-switcher preview blocking (FLAG_SECURE) and automatic clipboard sanitisation.

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⚙️ Building from Source

Prerequisites

• Flutter SDK: >= 3.12.0
• Android SDK: API level 26+ (Android 8.0 Oreo or newer)
• Android NDK: Installed via Android Studio SDK Manager (version specified in Gradle)
• CMake: 3.18.0+

Build Steps

1. Clone the repository:

   git clone https://github.com/R0b0To/VaultExplorer.git
   cd VaultExplorer

2. Fetch Flutter packages:

   flutter pub get

3. Build Release APK:

   flutter build apk --release

Note: During the build, CMake will automatically pull and compile the native C++ dependencies (mbedTLS, FatFs, NTFS-3G, libext2fs, Dislocker, cJSON, and VeraCrypt 1.26.29 source primitives).

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