Aminmart Password Manager

Native Android password manager app built with Kotlin, Jetpack Compose, and modern Android architecture components.

Security Features

Production-Grade Encryption

This app implements industry-standard security using Android's recommended cryptographic practices:

1. AES-256-GCM Encryption

• Algorithm: AES (Advanced Encryption Standard) with 256-bit key
• Mode: GCM (Galois/Counter Mode) - authenticated encryption
• IV Size: 96 bits (12 bytes) - NIST recommended
• Tag Size: 128 bits - for authentication

2. Android Keystore System

• Keys stored in hardware-backed secure enclave (when available)
• Keys never leave the secure hardware
• Protection against root attacks
• Key attestation support (on compatible devices)

3. PBKDF2 Password Hashing

• Algorithm: PBKDF2WithHmacSHA256
• Iterations: 100,000 (OWASP recommended minimum)
• Salt: 256-bit random salt per password
• Output: 256-bit hash

Security Architecture

Master Password → PBKDF2 → Hash (stored for verification)
                    ↓
Master Password → Android Keystore → AES Key (hardware-backed)
                    ↓
AES-256-GCM → Encrypt/Decrypt Password Data

Tech Stack

• Language: Kotlin 2.0.21
• UI: Jetpack Compose with Material 3
• Architecture: MVVM with Clean Architecture
• DI: Hilt (Dagger)
• Database: SQLite (hand-written SQLiteOpenHelper)
• Navigation: Jetpack Navigation Compose
• Security: AndroidX Security Crypto, Android Keystore

Getting Started

Prerequisites

• Android Studio Hedgehog (2023.1.1) or newer
• JDK 17
• Android SDK 35 (target), SDK 26 (minimum)

Build & Run

1. Open in Android Studio

   # Open the project folder in Android Studio

2. Sync Gradle

   • Android Studio will automatically sync
   • Wait for dependencies to download

3. Run the App

   • Select an emulator or physical device
   • Click Run (Shift+F10)

Build from Command Line

# Debug build
./gradlew assembleDebug

# Release build
./gradlew assembleRelease

# Run tests
./gradlew test

# Install on connected device
./gradlew installDebug

Project Structure

app-password-manager/
├── app/
│   ├── src/main/
│   │   ├── java/com/aminmart/passwordmanager/
│   │   │   ├── data/
│   │   │   │   ├── local/           # SQLiteOpenHelper, entities
│   │   │   │   ├── repository/      # Data repositories
│   │   │   │   └── security/        # Encryption services
│   │   │   ├── domain/
│   │   │   │   └── model/           # Domain models
│   │   │   ├── di/                  # Hilt modules
│   │   │   ├── ui/
│   │   │   │   ├── navigation/      # Navigation
│   │   │   │   ├── screens/         # Compose screens & ViewModels
│   │   │   │   ├── components/      # Reusable components
│   │   │   │   └── theme/           # Material theme
│   │   │   ├── MainActivity.kt
│   │   │   └── PasswordManagerApplication.kt
│   │   ├── res/                     # Resources
│   │   └── AndroidManifest.xml
│   └── build.gradle.kts
├── gradle/
│   └── libs.versions.toml
├── build.gradle.kts
└── settings.gradle.kts

Features

• 🔐 Master Password - Secure vault with PBKDF2 verification
• 🧬 Biometric Unlock - Fingerprint/face authentication
• 🔑 Password Generator - Strong random passwords with strength indicator
• 📱 Categories - Organize passwords by type
• 🔍 Search - Quick search through passwords
• 📤 Encrypted Backup - Export/import encrypted backups
• 📋 Copy to Clipboard - Easy password copying
• 🎨 Material 3 UI - Modern, beautiful interface

Security Best Practices

1. ✅ Hardware-backed Keystore
2. ✅ Authenticated Encryption (AES-GCM)
3. ✅ Unique Nonce per encryption
4. ✅ Strong KDF (PBKDF2 100k iterations)
5. ✅ Constant-time password comparison
6. ✅ No cloud backup (excluded)
7. ✅ Biometric authentication option

Database Schema

Passwords Table

CREATE TABLE passwords (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    title TEXT NOT NULL,
    username TEXT,
    password_encrypted TEXT,
    website TEXT,
    notes_encrypted TEXT,
    category TEXT NOT NULL,
    icon TEXT,
    ciphertext TEXT,      -- Encrypted password + notes payload
    nonce TEXT,           -- GCM nonce
    createdAt INTEGER NOT NULL,
    updatedAt INTEGER NOT NULL
)

Settings Table

CREATE TABLE settings (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    key TEXT NOT NULL UNIQUE,
    value TEXT
)

License

Educational purposes only. Use at your own risk.

Resources

• Android Security Best Practices
• Android Keystore
• OWASP Password Storage