MALTIAM-1104: CAPTCHA service

CERN · Sep 8, 2020 · b1e12b5 · b1e12b5
1 parent 5c98346
commit b1e12b5
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Showing 13 changed files with 472 additions and 9 deletions.
diff --git a/.gitignore b/.gitignore
@@ -131,7 +131,6 @@ dmypy.json
 .vscode
 .idea
 config
-.gitlab-ci.yml
 openshift
 coverage_html_report
 

diff --git a/gitlab-ci.yml → .gitlab-ci.yml b/gitlab-ci.yml → .gitlab-ci.yml
@@ -1,7 +1,9 @@
 image: python:3.8-slim
 variables:
   NAMESPACE_PROD: captcha
-  APP_NAME: ${CI_PROJECT_NAME}
+  APP_NAME: captcha-api
+  PROD_TAG: latest
+  OPENSHIFT_SERVER_PROD: "https://openshift.cern.ch"
 
 stages:
   - lint
@@ -27,10 +29,9 @@ stages:
   stage: deploy
   image: gitlab-registry.cern.ch/paas-tools/openshift-client:latest
   script:
-    - LOWERCASE_PATH=$(echo ${CI_PROJECT_PATH} | awk '{ print tolower($0) } ')
     # Adding || true to disable the error message when the image already exists
-    - oc import-image ${APP_NAME} --from="gitlab-registry.cern.ch/${LOWERCASE_PATH}:${TAG}" --confirm --token=${TOKEN} --server=${OPENSHIFT_SERVER} -n ${NAMESPACE} || true
-    - oc tag "gitlab-registry.cern.ch/${LOWERCASE_PATH}:${TAG}" "${APP_NAME}:latest" --token=${TOKEN} --server=${OPENSHIFT_SERVER} -n ${NAMESPACE}
+    - oc import-image ${APP_NAME} --from="${CI_REGISTRY_IMAGE}:${TAG}" --confirm --token=${OS_TOKEN} --server=${OPENSHIFT_SERVER} -n ${NAMESPACE} || true
+    - oc tag "${CI_REGISTRY_IMAGE}:${TAG}" "${APP_NAME}:latest" --token=${OS_TOKEN} --server=${OPENSHIFT_SERVER} -n ${NAMESPACE}
 
 ### Linting
 flake8:
@@ -81,17 +82,14 @@ build_docker_prod:
     - master # the branch you want to publish
 
 ### Deployment definitions
-
-
 deploy_prod:
   <<: *deploy_definition
   variables:
     ENVIRONMENT: prod
-    TOKEN: ${OPENSHIFT_DEPLOY_TOKEN}
+    OS_TOKEN: ${OPENSHIFT_DEPLOY_TOKEN}
     OPENSHIFT_SERVER: ${OPENSHIFT_SERVER_PROD}
     NAMESPACE: ${NAMESPACE_PROD}
     TAG: ${PROD_TAG}
-    ROUTE_HOSTNAME: https://captcha.web.cern.ch
   environment:
     name: prod
     url: https://captcha.web.cern.ch

diff --git a/captcha_api/app_factory.py b/captcha_api/app_factory.py
@@ -0,0 +1,74 @@
+from celery import Celery
+from flask import Blueprint, Flask, redirect
+from flask_cors import CORS
+from werkzeug.middleware.proxy_fix import ProxyFix
+
+from captcha_api.database import db
+from captcha_api.log_utils import configure_logging
+from captcha_api.rest import api
+
+index_bp = Blueprint('index', __name__)
+
+celery = Celery()
+
+
+@index_bp.route("/")
+def index():
+    return redirect("/swagger-ui")
+
+
+def read_env_config(app: Flask):
+    try:
+        app.config.from_envvar("CAPTCHA_API_CONFIG")
+    except Exception as e:
+        app.logger.error(e)
+
+
+def setup_api(app: Flask):
+    api.version = app.config['API_VERSION']
+    api.prefix = f"/api/{api.version}"
+    api.init_app(app)
+
+
+def make_celery(app):
+    """
+    Sets up Celery as a background task runner for the application
+    """
+    if app.config.get('USE_CELERY', False):
+        celery.conf.broker_url = app.config['CELERY_BROKER_URL']
+        celery.conf.result_backend = app.config['CELERY_RESULT_BACKEND']
+        celery.conf.update(app.config)
+
+        class ContextTask(celery.Task):
+            def __call__(self, *args, **kwargs):
+                with app.app_context():
+                    return self.run(*args, **kwargs)
+
+        celery.Task = ContextTask
+    else:
+        app.logger.warn('Celery is disabled!')
+
+
+def create_app() -> Flask:
+    app = Flask(__name__)
+    app.wsgi_app = ProxyFix(app.wsgi_app)
+    CORS(app)
+    app.url_map.strict_slashes = False
+    app.config.from_object("captcha_api.config")
+    app.logger = configure_logging()
+    read_env_config(app)
+
+    # Create a Celery connection
+    make_celery(app)
+
+    # DB initialization
+    with app.app_context():
+        db.init_app(app)
+        db.create_all()
+
+    setup_api(app)
+
+    # Blueprints
+    app.register_blueprint(index_bp)
+
+    return app
diff --git a/captcha_api/captcha_generator.py b/captcha_api/captcha_generator.py
@@ -0,0 +1,71 @@
+from io import BytesIO
+from random import randint
+from typing import Tuple
+
+from PIL import Image, ImageDraw, ImageFont, ImageOps
+
+
+def _get_random_color():
+    #  random color rgb
+    return randint(120, 200), randint(120, 200), randint(120, 200)
+
+
+def _get_random_code():
+    #  random characters
+    codes = [[chr(i) for i in range(49, 58)], [chr(i)
+                                               for i in range(65, 91)], [chr(i) for i in range(97, 123)]]
+    codes = codes[randint(0, 2)]
+    return codes[randint(0, len(codes) - 1)]
+
+
+def _generate_rotated_char(c, font):
+    txt = Image.new('L', font.getsize(c))
+    blank_image = ImageDraw.Draw(txt)
+    blank_image.text((0, 0), c, font=font, fill=255)
+    rotated_text = txt.rotate(randint(-50, 50), expand=1)
+    return rotated_text
+
+
+class CaptchaGenerator:
+    """
+    Generates captcha images based on the parameters
+    """
+
+    def __init__(self, fontname="DejaVuSerif.ttf", width=250, height=60):
+        self.width = width
+        self.height = height
+        self.font = ImageFont.truetype(fontname, size=36)
+
+    def generate_captcha(self, length=6) -> Tuple[BytesIO, str]:
+        """
+        Generate a captcha image
+        :return: A tuple consisting of the image bytes and the text
+        """
+        img = Image.new("RGB", (self.width, self.height), (250, 250, 250))
+        draw = ImageDraw.Draw(img)
+        #  captcha text
+        text = ""
+        for i in range(length):
+            char = _get_random_code()
+            text += char
+
+            rotated = _generate_rotated_char(char, self.font)
+            colorized = ImageOps.colorize(
+                rotated, (0, 0, 0), _get_random_color())
+            img.paste(colorized, (int(self.width * 0.13 * (i + 1)),
+                                  int(self.height * 0.2)), rotated)
+        #  add interference line
+        for i in range(15):
+            x_1 = randint(0, self.width)
+            y_1 = randint(0, self.height)
+            x_2 = randint(0, self.width)
+            y_2 = randint(0, self.height)
+            draw.line((x_1, y_1, x_2, y_2), fill=_get_random_color())
+        #  add interference point
+        for i in range(16):
+            draw.point((randint(0, self.width), randint(
+                0, self.height)), fill=_get_random_color())
+        #  save the picture
+        img_byte_array = BytesIO()
+        img.save(img_byte_array, format='jpeg')
+        return img_byte_array, text
diff --git a/captcha_api/celery_worker.py b/captcha_api/celery_worker.py
@@ -0,0 +1,17 @@
+import os
+
+from celery.schedules import crontab
+
+from captcha_api.app_factory import celery, create_app
+from captcha_api.tasks import delete_old_captchas
+
+app = create_app()
+
+
+@celery.on_after_configure.connect
+def setup_periodic_tasks(sender, **kwargs):
+    # Executes every hour the delete old captchas task
+    sender.add_periodic_task(
+        crontab(hour="*/1"),
+        delete_old_captchas.s(),
+    )
diff --git a/captcha_api/config.py b/captcha_api/config.py
@@ -0,0 +1,11 @@
+API_VERSION = "v1.0"
+
+# Local database
+SQLALCHEMY_DATABASE_URI = "sqlite:///test.db"
+DEFAULT_CAPTCHA_FONT = "DejaVuSerif.ttf"
+
+# Set to True for Celery background tasks functionality
+USE_CELERY = False
+
+CELERY_BROKER_URL = "redis://localhost:6379"
+CELERY_RESULT_BACKEND = "redis://localhost:6379"
diff --git a/captcha_api/database.py b/captcha_api/database.py
@@ -0,0 +1,14 @@
+import datetime
+
+from flask_sqlalchemy import SQLAlchemy
+
+db = SQLAlchemy()
+
+
+class Captcha(db.Model):
+    id = db.Column(db.String(36), primary_key=True)
+    answer = db.Column(db.String(120), nullable=False)
+    creation_time = db.Column(db.DateTime, default=datetime.datetime.utcnow, nullable=False)
+
+    def __repr__(self):
+        return '<Captcha %r>' % self.id
diff --git a/captcha_api/log_utils.py b/captcha_api/log_utils.py
@@ -0,0 +1,23 @@
+import logging
+import sys
+
+
+def configure_logging():
+    """Logging setup
+    """
+    logger = logging.getLogger(__name__)
+    logger.setLevel(logging.DEBUG)
+    formatter = logging.Formatter("%(asctime)s %(levelname)s %(filename)s:%(lineno)d - %(message)s")
+
+    # adds console handler to logger instance the first time this code is called
+    # avoids adding extra handlers to the instance, which causes duplicate logs msgs
+    if not len(logger.handlers):
+        console = logging.StreamHandler(sys.stdout)
+        console.setFormatter(formatter)
+        logger.addHandler(console)
+
+    # Requests logs some stuff at INFO that we don't want
+    # unless we have DEBUG
+    requests_log = logging.getLogger("requests")
+    requests_log.setLevel(logging.ERROR)
+    return logger
diff --git a/captcha_api/rest.py b/captcha_api/rest.py
@@ -0,0 +1,96 @@
+import logging
+import re
+from base64 import b64encode
+from copy import deepcopy
+from datetime import datetime, timedelta
+from urllib.parse import urlparse
+from uuid import uuid4
+
+from flask import current_app, jsonify, request
+from flask_restx import Api, Resource, fields
+
+from captcha_api.captcha_generator import CaptchaGenerator
+from captcha_api.database import Captcha, db
+
+api = Api(
+    title="CAPTCHA API",
+    description="A simple API for handling CAPTCHA",
+    security={'oauth2': ['api']},
+    doc="/swagger-ui",
+)
+
+
+captcha_ns = api.namespace(
+    "captcha", description="Utilities for validating and generating CAPTCHA")
+
+
+captcha_model = captcha_ns.model(
+    "CaptchaAnswer",
+    {
+        "answer": fields.String,
+        "id": fields.String
+    }
+)
+
+
+def get_request_data(request):
+    """
+    Gets the data from the request
+    """
+    # https://stackoverflow.com/questions/10434599/how-to-get-data-received-in-flask-request/25268170
+    data = request.form.to_dict() if request.form else request.get_json()
+    if not data:
+        return {}
+    return data
+
+
+@captcha_ns.route("/")
+class CaptchaResource(Resource):
+    """
+    Handling captchas
+    """
+
+    def __init__(self, api=None, *args, **kwargs):
+        super().__init__(api=api, *args, **kwargs)
+        self.generator = CaptchaGenerator(
+            fontname=api.app.config['DEFAULT_CAPTCHA_FONT'])
+
+    def get(self):
+        """
+        Generate a new captcha text
+        """
+        img_array, answer = self.generator.generate_captcha()
+        captcha_id = str(uuid4())
+        new_captcha = Captcha(id=captcha_id, answer=answer)
+        db.session.add(new_captcha)
+        db.session.commit()
+        return {
+            "id": captcha_id,
+            "img": "data:image/jpeg;base64," + b64encode(img_array.getvalue()).decode()
+        }
+
+    @captcha_ns.doc(body=captcha_model)
+    def post(self):
+        """
+        Solve a captcha and match it with the database thing
+        """
+        data = get_request_data(request)
+
+        existing = Captcha.query.filter_by(id=data["id"]).first()
+        if not existing:
+            return {"message": "Not found"}, 404
+
+        time_difference = datetime.utcnow() - existing.creation_time
+        if time_difference > timedelta(minutes=1):
+            db.session.delete(existing)
+            db.session.commit()
+            return {"message": "You did not answer fast enough!"}, 400
+
+        if data["answer"].casefold() != existing.answer.casefold():
+            db.session.delete(existing)
+            db.session.commit()
+            return {"message": "Invalid answer"}, 400
+
+        db.session.delete(existing)
+        db.session.commit()
+        return {"message": "Valid"}
diff --git a/captcha_api/tasks.py b/captcha_api/tasks.py
@@ -0,0 +1,13 @@
+from datetime import datetime, timedelta
+
+from captcha_api.app_factory import celery
+from captcha_api.database import Captcha, db
+
+
+@celery.task
+def delete_old_captchas():
+    one_hour_ago = datetime.utcnow() - timedelta(hours=1)
+    old_captchas = Captcha.query.filter(
+        Captcha.creation_time <= one_hour_ago)
+    old_captchas.delete()
+    db.session.commit()
-Original file line number
+Diff line change
@@ Expand Up / @@ -131,7 +131,6 @@ dmypy.json @@
     .vscode
     .idea
     config
-    .gitlab-ci.yml
     openshift
     coverage_html_report
@@ Expand Down @@