https://github.com/kelo221/goptcha
Simple implementation of a captcha written in Go. No external dependencies.
https://github.com/kelo221/goptcha
captcha captcha-generator go golang
Last synced: 4 months ago
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Simple implementation of a captcha written in Go. No external dependencies.
- Host: GitHub
- URL: https://github.com/kelo221/goptcha
- Owner: kelo221
- License: mpl-2.0
- Created: 2022-07-17T16:40:06.000Z (almost 4 years ago)
- Default Branch: master
- Last Pushed: 2024-10-15T20:54:14.000Z (over 1 year ago)
- Last Synced: 2025-09-05T17:02:18.601Z (9 months ago)
- Topics: captcha, captcha-generator, go, golang
- Language: Go
- Homepage:
- Size: 1.13 MB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# Goptcha
### A proof of concept captcha solution done in Golang.
## Example using Fiber
```go
package main
import (
"bytes"
"fmt"
"github.com/gofiber/fiber/v2"
"github.com/gofiber/fiber/v2/middleware/session"
"github.com/kelo221/goptcha"
"image/png"
"log"
"net/http"
"time"
)
var capchaStore *session.Store
func main() {
app := fiber.New()
capchaStore = session.New(session.Config{
Expiration: time.Minute * 1,
CookieSecure: true,
CookieHTTPOnly: true,
})
Goptcha.Configure(&Goptcha.Config{
ImageSizeMultiplier: 4,
CharSet: "ABCDEFGHIJKLMNOPQRSTUVWXYZ",
CharacterCount: 8,
Opacity: 100,
})
app.Get("/captcha", getCaptcha)
app.Post("/checker", restricted)
err := app.Listen(":3000")
if err != nil {
return
}
}
func getCaptcha(c *fiber.Ctx) error {
captchaString, img := Goptcha.GenerateCaptcha()
fmt.Println(captchaString)
sess, err := capchaStore.Get(c)
if err != nil {
panic(err)
}
sess.Set("captcha", captchaString)
if err := sess.Save(); err != nil {
panic(err)
}
// Create a new buffer and encode an image to it
buf := new(bytes.Buffer)
if err := png.Encode(buf, img); err != nil {
log.Println(err)
return c.SendStatus(fiber.StatusInternalServerError)
}
// Set the content type header to image/jpeg
c.Set(fiber.HeaderContentType, "image/png")
// Write the image bytes to the response body
if _, err := c.Write(buf.Bytes()); err != nil {
log.Println(err)
return c.SendStatus(fiber.StatusInternalServerError)
}
return nil
}
func restricted(c *fiber.Ctx) error {
var data map[string]string
if err := c.BodyParser(&data); err != nil {
println("parsing error")
return err
}
if data["captcha"] == "" {
c.Status(400)
return c.Status(400).JSON(fiber.Map{
"message": "Missing captcha!",
})
}
sess, err := capchaStore.Get(c)
if err != nil {
log.Println(err)
}
captcha := sess.Get("captcha")
log.Println(captcha, data["captcha"])
if captcha != data["captcha"] {
return c.Status(http.StatusBadRequest).JSON(fiber.Map{"error": "Incorrect captcha!"})
}
return c.Status(http.StatusOK).JSON(fiber.Map{"Success": "Correct captcha!"})
}
```
Here `localhost:3000/captcha` returns an randomly generated image, which contains text that is passed to the `localhost:3000/checker` endpoint for verification.
Execution time for a single image is about 2 milliseconds.
*Sample captcha*