passgen

A secure, customizable password generator CLI tool written in Go with clean architecture.

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  passgen v1.1.0
  Cryptographically secure password generation

Features

• 🔐 Secure Random Generation — Uses crypto/rand for cryptographically secure randomness
• 🎨 Customizable Character Sets — Lowercase, uppercase, numbers, symbols (toggle individually)
• 🔄 No-Repeat Mode — --no-repeat flag guarantees no duplicate characters with full type coverage
• 🎯 Word-Based Passwords — Transform memorable words into secure passwords (6 strategies, 3 complexity levels)
• 🔍 Password Strength Checker — Analyze strength and get improvement suggestions
• 🚀 Preset Configurations — Quick presets: secure, simple, pin, alphanumeric
• 📦 Batch Generation — Generate multiple unique passwords at once
• 🌍 Cross-Platform — Linux, macOS, Windows

Installation

Quick Install (Recommended)

curl -sSL https://raw.githubusercontent.com/kumarasakti/passgen/main/install.sh | bash

Go Install

go install github.com/kumarasakti/passgen@latest

After go install, add Go's bin to PATH: export PATH=$PATH:$(go env GOPATH)/bin

PowerShell

irm https://raw.githubusercontent.com/kumarasakti/passgen/main/install.ps1 | iex

Build from Source

git clone https://github.com/kumarasakti/passgen.git
cd passgen
make build
sudo mv build/passgen /usr/local/bin/

Pre-built Binaries

Download from the releases page.

Verify

passgen --version
passgen --help

Usage

Basic Generation

passgen                          # Default 14-char password (lower, upper, symbols)
passgen -l 16 -n                 # 16 chars with numbers
passgen --secure                 # All character types enabled
passgen -c 5                     # Generate 5 passwords

Advanced Options

passgen --no-repeat -l 20 --secure          # No duplicate characters
passgen --exclude-similar                   # Exclude i, l, 1, L, o, 0, O
passgen --exclude "aeiou"                   # Exclude specific characters
passgen --lower=false --upper=false -n -l 6 # PIN (numbers only)
passgen --alphanumeric -l 12               # Letters and numbers only

Word-Based Passwords

passgen word "security"                          # Default hybrid transformation
passgen word "sunshine" --strategy leetspeak    # s3cur1ty style
passgen word "secret" --complexity high          # Maximum complexity
passgen word "team" --count 3                    # 3 variations

Strategies: leetspeak · mixedcase · suffix · prefix · insert · hybrid (default)

Complexity: low · medium (default) · high

Presets

passgen preset secure        # 16 chars, all types
passgen preset simple        # 12 chars, letters + numbers
passgen preset pin           # 6 digits
passgen preset alphanumeric  # 12 chars, letters + numbers

Strength Checker

passgen check "mypassword123"

Command Line Options

Standard Generation

Flag	Short	Description	Default
--length	-l	Password length	14
--count	-c	Number of passwords to generate	1
--lower		Include lowercase letters	true
--upper		Include uppercase letters	true
--numbers	-n	Include numbers	false
--symbols	-s	Include symbols	true
--no-repeat		Avoid duplicate characters (guaranteed type coverage)	false
--exclude-similar		Exclude similar characters (il1Lo0O)	false
--exclude		Characters to exclude	""
--secure	-S	Enable all character types	false
--simple	-m	Letters + numbers only	false
--alphanumeric	-a	Alphanumeric only	false
--help	-h	Show help
--version	-v	Show version

Word-Based Generation

passgen word <word> [flags]

Flag	Short	Description	Default	Options
--strategy	-s	Transformation strategy	hybrid	leetspeak, mixedcase, suffix, prefix, insert, hybrid
--complexity	-x	Complexity level	medium	low, medium, high
--count	-c	Number of variations	1

Examples

$ passgen
🎯 Your Password:
┌────────────────┐
│ U$DD$fico*Q,.Y │
└────────────────┘
📊 Length: 14 | Character types: Lowercase, Uppercase, Symbols | Strength: Very Strong 💪
🔒 Security info: 88.0 bits entropy, cracks in 4892016 years
💬 Someone's taking this security thing seriously! 🌟

$ passgen --secure -l 20 --no-repeat
🎯 Your Password:
┌──────────────────────┐
│ dP$<c1Xk6.q9!jLv7bRz │
└──────────────────────┘
📊 Length: 20 | Character types: Lowercase, Uppercase, Numbers, Symbols | Strength: Extremely Strong 🔥
🔒 Security info: 101.3 bits entropy, cracks in 5.4e+19 years
💬 Brr, that's ice cold security! Even hackers are shivering! 🥶

Development

make deps       # Install dependencies
make build      # Build for current platform
make build-all  # Build for all platforms
make test       # Run all tests
make dev        # Format, lint, test, build
make release    # Create release archives

Security

This tool uses Go's crypto/rand package for cryptographically secure random number generation. Generated passwords are suitable for production use.

Contributing

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add some amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

License

MIT License — see LICENSE for details.

Changelog

v1.1.0

• Word-Based Password Generation — 6 transformation strategies, 3 complexity levels
• No-Repeat Mode — --no-repeat flag for no-duplicate passwords with guaranteed type coverage
• Batch Uniqueness — GenerateMultiplePasswords retries on collisions
• BuildCategories — Per-category charset support for guaranteed character type coverage
• Fisher-Yates Shuffle — Cryptographically secure shuffle for no-repeat mode
• Clean Architecture — Domain-Driven Design with domain/application/infrastructure layers
• Comprehensive Testing — 30+ test cases across all architectural layers
• Fully backward compatible

v1.0.0

• Initial release
• Basic password generation with customizable options
• Password strength checker
• Preset configurations
• Cross-platform support