Passcore

Passcore is a Rust library for scoring password strength using a transparent, multi-factor methodology. It provides a simple API to evaluate passwords and returns a score out of 1000, with detailed breakdowns for length, character variety, uniqueness, and penalties for common patterns.

Features

• Password scoring out of 1000 points
• Factors: length, character variety, uniqueness, penalties
• Penalty for common passwords and patterns
• Extensible scoring system for future techniques
• Includes 100k most-used passwords for penalty checks
• Simple Rust API

Installation

Add Passcore to your Cargo.toml:

[dependencies]
passcore = "0.2.0"

Usage

Import and use the scoring functions:

Basic Scoring

use passcore::score;

let password = "MyS3cureP@ssw0rd!";
let score = score(password);
println!("Your password's score is {}", score);

Get a Letter Grade

use passcore::grade_password;

let password = "MyS3cureP@ssw0rd!";
let grade = grade_password(password);
println!("Your password's grade is: {}", grade);

Get Improvement Suggestions

use passcore::review_password;

let password = "weak";
let feedback = review_password(password);
println!("Feedback: {}", feedback);

Scoring Breakdown

• Length: up to 400 points
• Character Variety: up to 200 points
• Uniqueness: up to 200 points
• Penalties: up to 200 points (deducted for common passwords or patterns)

Score Labels

• <450 -> F
• 450–549 -> D-
• 550–599 -> D
• 600–649 -> D+
• 650–699 -> C-
• 700–749 -> C
• 750–799 -> C+
• 800–849 -> B-
• 850–899 -> B
• 900–949 -> B+
• 950–979 -> A-
• 980–994 -> A
• 995+ -> A+

Performance

This release includes significant performance optimizations, reducing scoring time by 79.7%:

Benchmark	Before	After	Improvement
Average Passcore time	0.304455 ms	0.061869 ms	79.7% faster
Average zxcvbn time	0.083165 ms	0.076520 ms	8.0% faster
Average password_strength time	0.235982 ms	0.221022 ms	6.3% faster

Benchmarks measured on 1000 randomly generated passwords (8-24 characters) using comparative testing against zxcvbn and password_strength libraries. In addition I tested twice so I thought to give you the small change of the other two libraries even though it fluctuates.

API Reference

score(password: &str) -> u16

Scores a password on a scale of 0-1000 based on length, variety, uniqueness, and common pattern penalties.

grade_password(password: &str) -> &str

Returns a letter grade (F to A+) based on the password score.

review_password(password: &str) -> &str

Provides actionable feedback on which aspect of the password needs improvement (length, variety, uniqueness, or common patterns).

Contributing

Contributions are welcome! Please open issues or pull requests for improvements, bug fixes, or new scoring techniques.

License

This project is licensed under the MIT License.