captchas

README

Captchas

Base64 Captchas Manager, supports multiple drivers(digit, math, audio, string, chinese etc.) and stores(memory, redis etc.).

Usage

Preview: http://129.204.189.159:10000/.

$ cd example
$ go run main.go

Drivers

import "github.com/clevergo/captchas/drivers"

Digit

// all options are optianal.
opts := []drivers.DigitOption{
	drivers.DigitHeight(50),
	drivers.DigitWidth(120),
	drivers.DigitLength(6),
	drivers.DigitMaxSkew(0.8),
	drivers.DigitDotCount(80),
}
driver := drivers.NewDigit(opts...)

Audio

// all options are optianal.
opts := []drivers.AudioOption{
	drivers.AudioLangauge("en"),
	drivers.AudioLength(6),
}
driver := drivers.NewAudio(opts...)

Math

// all options are optianal.
opts := []drivers.MathOption{
	drivers.MathHeight(50),
	drivers.MathWidth(120),
	drivers.MathNoiseCount(0),
	drivers.MathFonts([]string{}),
	drivers.MathBGColor(&color.RGBA{}),
}
driver := drivers.NewMath(opts...)

String

// all options are optianal.
opts := []drivers.StringOption{
	drivers.StringHeight(50),
	drivers.StringWidth(120),
	drivers.StringLength(4),
	drivers.StringNoiseCount(0),
	drivers.StringFonts([]string{}),
	drivers.StringSource("abcdefghijklmnopqrstuvwxyz"),
	drivers.StringBGColor(&color.RGBA{}),
}
driver := drivers.NewString(opts...)

Chinese

// all options are optianal.
opts := []drivers.ChineseOption{
	drivers.ChineseHeight(50),
	drivers.ChineseWidth(120),
	drivers.ChineseLength(4),
	drivers.ChineseNoiseCount(0),
	drivers.ChineseFonts([]string{"wqy-microhei.ttc"}),
	drivers.ChineseSource("零一二三四五六七八九十"),
	drivers.ChineseBGColor(&color.RGBA{}),
}
driver := drivers.NewChinese(opts...)

Stores

Memory Store

import "github.com/clevergo/captchas/memstore"

expiration := 10 * time.Minute // captcha expiration.
gcInterval := time.Minute // garbage collection interval to delete expired captcha.
store := memstore.New(expiration, gcInterval)

Inspired by scs.memstore.

Redis Store

import (
    "github.com/clevergo/captchas/redisstore"
    "github.com/go-redis/redis/v7"
)

// redis client.
client := redis.NewClient(&redis.Options{
	Addr: "localhost:6379",
})
prefix := "captcha"            // redis key prefix, optional.
expiration := 10 * time.Minute // captcha expiration.
store := redisstore.New(client, expiration, redisstore.Prefix(prefix))

More

Add your store here by PR or request a new store.

Documentation

Index

• Variables
• type Captcha
• type Driver
• type Manager
  • func New(store Store, driver Driver, opts ...Option) *Manager
  • func (m *Manager) Generate() (Captcha, error)
  • func (m *Manager) Get(id string, clear bool) (string, error)
  • func (m *Manager) Verify(id, actual string, clear bool) error
• type Option
  • func CaseSensitive(v bool) Option
• type Store

Variables

var (
	ErrIncorrectCaptcha = errors.New("incorrect captcha")
	ErrExpiredCaptcha   = errors.New("expired captcha")
)

Errors

Types

type Captcha

type Captcha interface {
	// ID returns captcha ID.
	ID() string

	// Answer returns captcha answer.
	Answer() string

	// EncodeToString returns encoded base64 string.
	EncodeToString() string

	// HTMLField returns a template.HTML that includes captcha ID hidden input field
	// and media field(audio/img).
	HTMLField(fieldName string) template.HTML
}

Captcha is an interface that captchas that generated by driver should implements.

type Driver

type Driver interface {
	// Generate generates a new captcha, returns an error if failed.
	Generate() (Captcha, error)
}

Driver defines how to generate captchas.

type Manager

type Manager struct {
	// contains filtered or unexported fields
}

Manager is a captchas manager.

func New

func New(store Store, driver Driver, opts ...Option) *Manager

New returns a manager instance with the given store and driver.

func (*Manager) Generate

func (m *Manager) Generate() (Captcha, error)

Generate generates a new captcha and save it to store, returns an error if failed.

func (*Manager) Get

func (m *Manager) Get(id string, clear bool) (string, error)

Get is a shortcut of Store.Get.

func (*Manager) Verify

func (m *Manager) Verify(id, actual string, clear bool) error

Verify verifies whether the given actual value is equal to the answer of captcha, returns an error if failed.

type Option

type Option func(*Manager)

Option is a function that receives a pointer of manager.

func CaseSensitive

func CaseSensitive(v bool) Option

CaseSensitive is an option that enable or disable case sensitive.

type Store

type Store interface {
	// Get returns the answer of the given captcha ID, returns
	// an error if failed. Clear indicates whether delete the
	// captcha after fetching.
	Get(id string, clear bool) (string, error)

	// Set saves the captcha ID and answer, returns error
	// if failed.
	Set(id, answer string) error
}

Store defines how to save and load captcha information.