Google reCAPTCHA (v2 and v3) verification in Golang.

To get the package:

go get github.com/chanioxaris/go-recaptcha

reCAPTCHA v2:

• Simple usage with default values (httpClient: http.DefaultClient)

    package main
    
    import (
        "fmt"
    
        "github.com/chanioxaris/go-recaptcha"
    )
    
    func main() {
        rec, err := recaptcha.New(<secret>, recaptcha.WithVersion(2))
        if err != nil {
            panic(err)
        }
    
        if err = rec.Verify(<response>); err != nil {
            panic(err)
        }
    
        fmt.Println("Success")
    }
  

• Simple usage with custom http client

    package main
    
    import (
        "fmt"
    
        "github.com/chanioxaris/go-recaptcha"
    )
    
    func main() {
        customClient := &http.Client{Timeout: time.Second * 10}
        
        rec, err := recaptcha.New(
                <secret>, 
                recaptcha.WithVersion(2), 
                recaptcha.WithHTTPClient(customClient)
            )
        if err != nil {
            panic(err)
        }
    
        if err = rec.Verify(<response>); err != nil {
            panic(err)
        }
    
        fmt.Println("Success")
    }
  

• Get reCAPTCHA token from request body (g-recaptcha-response field)

    import (
    	"fmt"
    	"net/http"
    
    	"github.com/chanioxaris/go-recaptcha"
    )
    
    func Handler(w http.ResponseWriter, r *http.Request) {
    	rec, err := recaptcha.New(<secret>, recaptcha.WithVersion(2))
    	if err != nil {
    		panic(err)
    	}
    
    	response, err := rec.GetRequestToken(r)
    	if err != nil {
    		panic(err)
    	}
    
    	if err = rec.Verify(response); err != nil {
    		panic(err)
    	}
    
    	fmt.Println("Success")
    }
  

reCAPTCHA v3:

• Simple usage with default values (version: 3, action: "", score: 0.5, httpClient: http.DefaultClient)

    package main
    
    import (
        "fmt"
  
        "github.com/chanioxaris/go-recaptcha"
    )
  
    func main() {
        rec, err := recaptcha.New(<secret>)
        if err != nil {
            panic(err)
        }
    
        if err = rec.Verify(<response>); err != nil {
            panic(err)
        }
    
        fmt.Println("Success")
    }
  

• Simple usage with custom values

    package main
        
    import (
        "fmt"
  
        "github.com/chanioxaris/go-recaptcha"
    )
    
    func main() {
         customClient := &http.Client{Timeout: time.Second * 10}
         customAction := "custom-action"
         customScore := 0.7
    
        rec, err := recaptcha.New(
                <secret>, 
        		recaptcha.WithHTTPClient(customClient), 
        		recaptcha.WithAction(customAction), 
        		recaptcha.WithScore(customScore),
        	)
        if err != nil {
            panic(err)
        }
    
        if err = rec.Verify(<response>); err != nil {
            panic(err)
        }
    
        fmt.Println("Success")
    }
  

• Get reCAPTCHA token from request body (g-recaptcha-response field)

    package main
            
    import (
        "fmt"
        "net/http"
    
        "github.com/chanioxaris/go-recaptcha"
    )
    
    func Handler(w http.ResponseWriter, r *http.Request) {
        rec, err := recaptcha.New(<secret>)
        if err != nil {
            panic(err)
        }
    
        response, err := rec.GetRequestToken(r)
        if err != nil {
            panic(err)
        }
    
        if err = rec.Verify(response); err != nil {
            panic(err)
        }
    
        fmt.Println("Success")
    }
  

Middleware:

• Use middleware in REST API

    package main
  
    import (
        "log"
        "net/http"
    
        "github.com/gorilla/mux"
    
        "github.com/chanioxaris/go-recaptcha"
    )
    
    func main() {
        // Create a new recaptcha instance.
        rec, err := recaptcha.New(<secret>)
        if err != nil {
            panic(err)
        }
    
        // Setup router.
        router := mux.NewRouter().StrictSlash(true)
        // Use the recaptcha middleware.
        router.Use(recaptcha.Middleware(rec))
    
        // Setup endpoint handler.
        router.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
            w.Write([]byte("A Google reCAPTCHA protected endpoint"))
        })
    
        // Start server.
        log.Fatal(http.ListenAndServe(":8080", router))
    }
  

go-recaptcha is MIT licensed