Entropy

• Entropy
  • Description
  • Usage
  • References

Description

This package will calculate the entropy from a given string. The alphabet used to calculate the entropy can be specified.

Usage

package main

import (
	"fmt"

	"github.com/adroge/entropy"
)

func main() {
	password := "monkey"
	result, err := entropy.Calculate(password)
	if err != nil {
		fmt.Println("error: ", err)
		return
	}
	fmt.Printf("Strength of \"%s\" is %s, with entropy: %f\n", password, result, result.Bits)
}

$ go run main.go
Strength of "monkey" is very weak, with entropy: 28.202638

It's possible to change the alphabets and entropy strength bounds by utilizing the Alphabet(...) and Bounds(...) functions. If you wanted to include a subset of the Latin-1 Supplement characters, you could do it with Alphabet(...).

Unit tests are a good source of usage.

References

These aren't the only places, or even the original places, where the formula used can be found, but for my own reference I used the following:

• How to Calculate Password Entropy?
• Password Security: Complexity vs. Length
• Entropy as a measure of password strength