password_generator

Go library for generating cryptographically secure random passwords, with a built-in strength evaluator. Also includes a ready-to-use CLI.

Installation

go get github.com/jcoppede11/password_generator

Usage as a library

import "github.com/jcoppede11/password_generator"

password, err := generator.Generate(generator.Options{
    Length:     16,
    UseUpper:   true,
    UseLower:   true,
    UseNumbers: true,
    UseSymbols: true,
})
if err != nil {
    log.Fatal(err)
}

fmt.Println(password)
fmt.Println(generator.StrengthScore(password))

Options

Field	Type	Description	Default
Length	int	Password length (maximum: 128)	—
UseUpper	bool	Include uppercase letters (A–Z)	false
UseLower	bool	Include lowercase letters (a–z)	false
UseNumbers	bool	Include digits (0–9)	false
UseSymbols	bool	Include symbols (!@#$%^&*…)	false

StrengthScore

Evaluates the strength of any password and returns one of these values:

Result	Criterion
Weak	score < 3
Medium	score 3–4
Strong	score 5
Very strong	score ≥ 6

The score combines length (0–3 points) and character variety (0–4 points).

Usage as a CLI

go run cmd/password-generator/main.go -length=16 -uppercase=true -lowercase=true -numbers=true -symbols=true

Flags

Flag	Default	Description
-length	12	Password length
-uppercase	true	Include uppercase letters
-lowercase	true	Include lowercase letters
-numbers	true	Include numbers
-symbols	true	Include symbols

Example output

Generated password: aK3$gTz9@Lpw1Xm#
Strength:           Very strong

Project structure

.
├── generator.go          # Public API
├── generator_test.go
├── go.mod
├── internal/
│   └── app/
│       └── app.go        # CLI orchestration
└── cmd/
    └── password-generator/
        └── main.go       # Entry point

Tests

go test -v

Requirements

Go 1.24.2 or higher.

License

MIT