🛡️ Desktop-2FA

A secure, offline two-factor authentication (2FA) manager for desktop environments. Built with Python, featuring strong encryption and no cloud dependencies.

🌐 Landing Page: desktop-2fa.org

---

✨ Features

Feature	Description
🔐 Vault Security	AES-256-GCM encryption with Argon2id key derivation
⏱️ TOTP Generation	RFC 6238 compliant code generation
💻 Full CLI	Complete command-line interface for managing tokens
📋 Clipboard Support	Automatic copying of TOTP codes to clipboard
🔓 Stateless Design	Every command requires explicit password authentication
🛡️ Password Policy	Configurable password strength enforcement with zxcvbn
🧪 Well Tested	289 tests passing with comprehensive coverage
📖 Security Model	Detailed threat analysis and cryptographic design documentation

---

📸 Screenshots

Adding a new TOTP entry interactively

Generating a TOTP code for an entry

Renaming an entry with duplicate detection

Viewing version info and listing all entries

---

🚀 Quick Start

Installation

pip install desktop-2fa

Verify installation:

python -c "import desktop_2fa; print(desktop_2fa.__version__)"
# Output: 0.8.1dev

Basic Usage

# Initialize a new vault
d2fa vault init

# Add a new TOTP token
d2fa vault add GitHub GitHub JBSWY3DPEHPK3PXP

# List all entries
d2fa vault list

# Generate a code
d2fa code GitHub

Non-Interactive Usage

# Provide password via command line
d2fa vault add GitHub GitHub JBSWY3DPEHPK3PXP --password mypassphrase

# Provide password via file
d2fa vault add GitHub GitHub JBSWY3DPEHPK3PXP --password-file /path/to/passphrase.txt

---

📁 Vault Lifecycle

The vault is an encrypted storage file located at ~/.desktop-2fa/vault.

Vault Creation

When a command requires a vault and none exists:

1. The CLI prompts for a new password (interactive mode) or requires --password/--password-file (non-interactive mode)
2. An empty encrypted vault is created
3. A confirmation message is always printed: Vault created at <path>

Vault Loading

When a command requires a vault and it exists:

1. The CLI prompts for the existing password (interactive mode) or requires credentials (non-interactive mode)
2. The vault is decrypted and loaded
3. If the password is invalid, the CLI exits with typer.Exit(1)

Duplicate Entry Handling

The rename command enforces deterministic behavior when multiple entries match the target name:

• If multiple entries match the provided name (issuer or account_name), the rename is aborted
• Error message: Error: Multiple entries named '<name>' exist. Operation aborted. Resolve duplicates first.
• No entry is renamed in this case
• This check occurs before any mutation

---

📖 CLI Commands

Core Commands

Command	Description
d2fa vault add <name> <issuer> <secret>	Add a new TOTP entry
d2fa vault list	List all stored TOTP entries
d2fa vault rename <old> <new>	Rename an entry
d2fa vault remove <name>	Remove an entry
d2fa code <name> [--copy|--copy-only]	Generate TOTP code with clipboard copy options

Vault Management

Command	Description
d2fa vault init [--force]	Initialize a new vault
d2fa vault unlock	Open vault with weak password warning (if configured)
d2fa vault change-password	Change the vault password
d2fa vault backup	Create an encrypted backup of the vault
d2fa vault export <path>	Export vault to file
d2fa vault import <path> [--force]	Import vault from file

Global Options

Option	Description
--password <pwd>	Provide vault password directly
--password-file <path>	Read vault password from file
--json	Output in JSON format
--raw	Raw output (no formatting)
--quiet	Suppress non-essential output
--copy	Copy TOTP code to clipboard and display
--copy-only	Copy TOTP code to clipboard only
--force	Force operation (bypass confirmations)

---

🔒 Security

The vault uses:

• AES-256-GCM for authenticated encryption
• Argon2id for key derivation (time_cost=4, memory_cost=128MiB, parallelism=2)
• zxcvbn for password strength evaluation
• Versioned header for forward compatibility

Every command requires explicit password authentication. No session-based access.

Password Strength Evaluation

Desktop-2FA uses zxcvbn to evaluate password strength when creating or changing vault passwords:

• Score 0-2 (Weak): Easily guessable passwords (e.g., "password123")
• Score 3-4 (Strong): Resistant to common attacks (recommended)

Examples:

• ❌ Weak: password, 123456, qwerty, admin2024
• ✅ Strong: Battery-Horse-Staple-Correct, Mountain@River*2024, MySecureVault#42

Configuration (~/.config/d2fa/config.toml):

[security]
# Require strong passwords (score >= 3)
reject_weak_passwords = false  # warn but allow | true: reject weak passwords

When reject_weak_passwords = false:

• Weak passwords trigger a yellow warning
• User is prompted to confirm continuation
• Password acceptance is non-blocking

When reject_weak_passwords = true:

• Weak passwords are rejected immediately
• Command exits with error
• User must choose a stronger password

Backward Compatibility: If you have min_password_entropy set in your config (legacy option), it is recognized and treated as equivalent to requiring zxcvbn score >= 3.

Security Hardening (v0.8.0)

Version 0.8.0 maintains all previous security hardening from v0.7.3 and introduces modular architecture for better code isolation:

• Empty passwords are immediately rejected with a clear error message
• Permission errors are distinguished from missing vault files
• No Python stack traces are shown to users
• User-friendly error messages for filesystem permission issues
• Modular design separates CLI and core cryptographic components for enhanced security boundaries
• zxcvbn-based password strength evaluation (new in v0.8.0)

---

📚 Documentation