swift-password-validation

Password validation library for Swift with composable rules and localized error messages.

Overview

PasswordValidation provides type-safe password validation in Swift. It includes predefined validation rules and supports custom validation logic through dependency injection.

Features

• Predefined validators for common password requirements
• Custom validation logic via closure-based composition
• Dependencies library integration for testability
• Localized error messages in English and Dutch
• Sendable conformance for Swift concurrency

Installation

Swift Package Manager

Add the following to your Package.swift file:

dependencies: [
    .package(url: "https://github.com/coenttb/swift-password-validation.git", from: "0.0.1")
]

Then add PasswordValidation to your target dependencies:

.target(
    name: "YourTarget",
    dependencies: [
        .product(name: "PasswordValidation", package: "swift-password-validation")
    ]
)

Quick Start

Basic Usage

import PasswordValidation

// Use the default validator
let validator = PasswordValidation.default

do {
    let isValid = try validator.validate("MySecurePass123!")
    print("Password is valid: \(isValid)")
} catch let error as PasswordValidation.Error {
    print("Validation failed: \(error.description)")
}

With Dependencies

import Dependencies
import PasswordValidation

struct LoginService {
    @Dependency(\.passwordValidation) var passwordValidation

    func validateUserPassword(_ password: String) throws -> Bool {
        return try passwordValidation.validate(password)
    }
}

Usage Examples

Default Validator

The default validator implements standard security requirements:

• Length: 8-64 characters
• Uppercase: At least one uppercase letter (A-Z)
• Lowercase: At least one lowercase letter (a-z)
• Digits: At least one digit (0-9)
• Special Characters: At least one special character (!&^%$#@()/)

let validator = PasswordValidation.default
try validator.validate("MySecurePass123!") // Returns true

Simple Validator

The simple validator requires only 4+ characters:

let validator = PasswordValidation.simple
try validator.validate("test") // Returns true

Custom Validation

Create your own validation rules:

let customValidator = PasswordValidation { password in
    guard password.count >= 6 else {
        throw PasswordValidation.Error.tooShort(minLength: 6)
    }

    guard !password.lowercased().contains("password") else {
        throw PasswordValidation.Error.missingSpecialCharacter
    }

    return true
}

Error Handling

The library provides specific error types for different validation failures:

do {
    try PasswordValidation.default.validate("weak")
} catch PasswordValidation.Error.tooShort(let minLength) {
    print("Password too short, needs at least \(minLength) characters")
} catch PasswordValidation.Error.missingUppercase {
    print("Password needs an uppercase letter")
} catch PasswordValidation.Error.missingDigit {
    print("Password needs a digit")
} catch {
    print("Other validation error: \(error)")
}

Available Errors

• tooShort(minLength: Int) - Password is shorter than required
• tooLong(maxLength: Int) - Password exceeds maximum length
• missingUppercase - No uppercase letters found
• missingLowercase - No lowercase letters found
• missingDigit - No digits found
• missingSpecialCharacter - No special characters found

Related Packages

Dependencies

• swift-translating: A Swift package for inline translations.

Used By

• coenttb-web: A Swift package with tools for web development building on swift-web.
• swift-server-foundation: A Swift package with tools to simplify server development.

Third-Party Dependencies

• pointfreeco/swift-dependencies: A dependency management library for controlling dependencies in Swift.

License

This project is licensed under the Apache 2.0 License. See LICENSE for details.

Contributing

Contributions are welcome. Please open an issue or submit a pull request.