recaptchaVerification (TheAlgorithms#2417)

* recaptchaVerification

* recaptchaVerification

* recaptchaVerification1

* recaptchaVerification2

* recaptchaVerification3

* recaptchaVerification4

* recaptchaVerificatio5

* recaptchaVerificatio5

* recaptchaVerificatio6

* drawOnVideoStreamOpenCV

* matrixInverseMCAmethod

* fixingImports

* recaptchaVerificationfixes

* recaptchaVerificationfixes

* recaptchaVerificationfixes

* recaptchaVerificationfixes

* recaptchaVerificationfixes1

* recaptchaVerificationfixes1

* authenticate = login = render = redirect = print

Co-authored-by: Christian Clauss <[email protected]>

Author: santoshrajkumar

web_programming/recaptcha_verification.py

@@ -0,0 +1,66 @@
+"""
+Recaptcha is a free captcha service offered by Google in order to secure websites and
+forms.  At https://www.google.com/recaptcha/admin/create you can create new recaptcha
+keys and see the keys that your have already created.
+* Keep in mind that recaptcha doesn't work with localhost
+When you create a recaptcha key, your will get two separate keys: ClientKey & SecretKey.
+ClientKey should be kept in your site's front end
+SecretKey should be kept in your site's  back end
+
+# An example HTML login form with recaptcha tag is shown below
+
+    <form action="" method="post">
+        <h2 class="text-center">Log in</h2>
+        {% csrf_token %}
+        <div class="form-group">
+            <input type="text" name="username" required="required">
+        </div>
+        <div class="form-group">
+            <input type="password" name="password" required="required">
+        </div>
+        <div class="form-group">
+            <button type="submit">Log in</button>
+        </div>
+        <!-- Below is the recaptcha tag of html -->
+        <div class="g-recaptcha" data-sitekey="ClientKey"></div>
+    </form>
+
+    <!-- Below is the recaptcha script to be kept inside html tag -->
+    <script src="https://www.google.com/recaptcha/api.js" async defer></script>
+
+Below a Django function for the views.py file contains a login form for demonstrating
+recaptcha verification.
+"""
+import requests
+
+try:
+    from django.contrib.auth import authenticate, login
+    from django.shortcuts import redirect, render
+except ImportError:
+    authenticate = login = render = redirect = print
+
+
+def login_using_recaptcha(request):
+    # Enter your recaptcha secret key here
+    secret_key = "secretKey"
+    url = "https://www.google.com/recaptcha/api/siteverify"
+
+    # when method is not POST, direct user to login page
+    if request.method != "POST":
+        return render(request, "login.html")
+
+    # from the frontend, get username, password, and client_key
+    username = request.POST.get("username")
+    password = request.POST.get("password")
+    client_key = request.POST.get("g-recaptcha-response")
+
+    # post recaptcha response to Google's recaptcha api
+    response = requests.post(url, data={"secret": secret_key, "response": client_key})
+    # if the recaptcha api verified our keys
+    if response.json().get("success", False):
+        # authenticate the user
+        user_in_database = authenticate(request, username=username, password=password)
+        if user_in_database:
+            login(request, user_in_database)
+            return redirect("/your-webpage")
+    return render(request, "login.html")