Password validator library for Go

Installation

go get -u github.com/go-passwd/validator

Usage

import "github.com/go-passwd/validator"

passwordValidator := validator.New(validator.MinLength(5, nil), validator.MaxLength(10, nil))
err := passwordValidator.Validate(form.Password)
if err != nil {
  panic(err)
}

You can pass to every validator functions customError parameter witch will be returned on error instead of default error.

import "github.com/go-passwd/validator"

passwordValidator := validator.New(validator.MinLength(5, errors.New("too short")), validator.MaxLength(10, errors.New("too long")))
err := passwordValidator.Validate(form.Password)
if err != nil {
  panic(err)
}

Validators

CommonPassword

Check if password is a common password.

Common password list is based on list created by Mark Burnett: https://xato.net/passwords/more-top-worst-passwords/

passwordValidator := validator.New(validator.CommonPassword(nil))

ContainsAtLeast

Count occurrences of a chars and compares it with required value.

passwordValidator := validator.New(validator.ContainsAtLeast(5, "abcdefghijklmnopqrstuvwxyz", nil))

ContainsOnly

Check if password contains only selected chars.

passwordValidator := validator.New(validator.ContainsOnly("abcdefghijklmnopqrstuvwxyz", nil))

MaxLength

Check if password length is not greater that defined length.

passwordValidator := validator.New(validator.MaxLength(10, nil))

MinLength

Check if password length is not lower that defined length.

passwordValidator := validator.New(validator.MinLength(5, nil))

Noop

Always return custom error.

passwordValidator := validator.New(validator.Noop(nil))

Regex

Check if password match regexp pattern.

passwordValidator := validator.New(validator.Regex("^\\w+$", nil))

Similarity

Check if password is sufficiently different from the attributes.

Attributes can be: user login, email, first name, last name, …

passwordValidator := validator.New(validator.Similarity([]string{"username", "username@example.com"}, nil, nil))

StartsWith

Check if password starts with one of letter.

passwordValidator := validator.New(validator.StartsWith("abcdefghijklmnopqrstuvwxyz", nil))

Unique

Check if password contains only unique chars.

passwordValidator := validator.New(validator.Unique(nil))