Menulis layanan lembar memo satu kali dengan Python

Beberapa orang perlu menyampaikan pesan kecil. Tetapi bagaimana melakukan ini jika Anda menggunakan berbagai jejaring sosial dan pengirim pesan instan, dalam keamanan transfer data yang Anda ragukan.

Beberapa orang menggunakan layanan catatan terenkripsi yang dapat merusak diri sendiri untuk ini. Tetapi di sini muncul pertanyaan apakah layanan ini dapat dipercaya dan apakah mereka benar-benar menghancurkan catatan setelah membacanya.

Python cryptography Flask Heroku.

github
Heroku

Virtualenv.

virtualenv

pip install virtualenv

mkdir encnotes
cd encnotes
virtualenv venv
source venv/bin/activate ( nix )
venv\Scripts\activate ( Windows )

requirements.txt :

cryptography
Flask
Flask-Migrate
Flask-SQLAlchemy
Flask-WTF
Flask-Bootstrap
Flask-SSLify

pip , requirements.txt

pip install -r requirements.txt

encnotes.py. . . .

import os
import random
from cryptography.fernet import Fernet
from flask import Flask, render_template, url_for
from flask_sqlalchemy import SQLAlchemy
from flask_migrate import Migrate
from flask_wtf import FlaskForm
from flask_bootstrap import Bootstrap
from flask_sslify import SSLify
from wtforms import TextAreaField, SubmitField
from wtforms.validators import DataRequired, Length

,

class Config():
    SECRET_KEY = os.environ.get('SECRET_KEY')
    SQLALCHEMY_TRACK_MODIFICATIONS = False
    SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_URL')
    SITE_URL = 'https://encnote.herokuapp.com'

SECRET_KEY — . , , . Flask-WTF Cross-Site Request Forgery CSRF.

SQLALCHEMY_TRACK_MODIFICATIONS — ,
, .

SITE_URL — , Heroku.

Flask Config

app = Flask(__name__)
app.config.from_object(Config)
db = SQLAlchemy(app)
migrate = Migrate(app, db)
bootstrap = Bootstrap(app)
sslify = SSLify(app)

, . 3 :

• id — ,
• number — , .
  1000000 9999999
• ciptext —

.

class Note(db.Model):
    __tablename__ = 'notes'
    id = db.Column(db.Integer, primary_key=True)
    number = db.Column(db.Integer, unique=True, nullable=False)
    ciptext = db.Column(db.Text, nullable=False)

    def __repr__(self):
        return f'<Note number: {self.number}'

-

- , Flask-WTF

class TextForm(FlaskForm):
    text = TextAreaField('  ( 1000 )',
                         validators=[DataRequired(), Length(1, 1000)])
    submit = SubmitField('')

• text — . 2 . , . 1000 . .

. .

@app.shell_context_processor
def make_shell_context():
    return {'db': db, 'Note': Note}

,

@app.route('/', methods=['GET', 'POST'])
def index():
    form = TextForm()
    if form.validate_on_submit():
        key = Fernet.generate_key()
        str_key = key.decode('ascii')
        f = Fernet(key)
        bin_string = form.text.data.encode('utf-8')
        cipher_text = f.encrypt(bin_string)
        str_cipher_text = cipher_text.decode('ascii')
        rnumber = random.randint(1000000, 9999999)
        while True:
            n = Note.query.filter_by(number=rnumber).first()
            if n:
                rnumber = random.randint(1000000, 9999999)
                continue
            break
        cipher_note = Note(number=rnumber, ciptext=str_cipher_text)
        link = f'{app.config["SITE_URL"]}/{rnumber}/{str_key}'
        db.session.add(cipher_note)
        db.session.commit()
        return render_template('complete.html', link=link)
    return render_template('index.html', form=form)

, . POST, "". . URL-safe base64, "Ascii" URL. AES-128.

, URL-safe base64, , . , while , , . , html complete.html - . html Flask-Bootstrap, bootstrap.

, . , , . .. .

@app.route('/<rnumber>/<str_key>')
def question(rnumber, str_key):
    link = f'{app.config["SITE_URL"]}/decrypt/{rnumber}/{str_key}'
    return render_template('question.html', link=link)

"" ,

@app.route('/decrypt/<int:rnumber>/<str_key>')
def decrypt(rnumber, str_key):
    cipher_note = Note.query.filter_by(number=rnumber).first_or_404()
    cipher_text = cipher_note.ciptext.encode('ascii')
    key = str_key.encode('ascii')
    try:
        f = Fernet(key)
        text = f.decrypt(cipher_text)
    except (ValueError, InvalidToken):
        return render_template('error.html')
    text = text.decode('utf-8')
    db.session.delete(cipher_note)
    db.session.commit()
    return render_template('decrypt.html', text=text)

. try except.

Heroku

- Heroku. . , 30 , . , .

Heroku Heroku CLI. git
Heroku CLI

$ heroku login

git

$ git init

Heroku. , encnote

heroku apps:create encnote
Creating ⬢ encnote... done
https://encnote.herokuapp.com/ | https://git.heroku.com/encnote.git

, Heroku

heroku addons:add heroku-postgresql:hobby-dev
Creating heroku-postgresql:hobby-dev on ⬢ encnote... free
Database has been created and is available
 ! This database is empty. If upgrading, you can transfer
 ! data from another database with pg:copy
Created postgresql-graceful-12123 as DATABASE_URL
Use heroku addons:docs heroku-postgresql to view documentation

Heroku DATABASE_URL, . , , Flask

nix export FLASK_APP=encnotes.py
Windows set FLASK_APP=encnotes.py

,

$ export DATABASE_URL=sqlite:////home/user/Python/encnote/app.db ( nix )
$ set DATABASE_URL=sqlite:///D:\Python\encnotes\app.db ( Windows )

flask db init
flask db migrate

migrate, . app.db .

.gitignore , git Heroku

venv
__pycache__

- flask , gunicorn. Postgres psycopg2. http https, Flask-SSLify.

requirements.txt

gunicorn
psycopg2

Heroku , Procfile . :

web: flask db upgrade; gunicorn encnotes:app

Heroku. , .

, . SECRET_KEY .

heroku config:set SECRET_KEY=super-secret-work232
heroku config:set FLASK_APP=encnotes.py

DATABASE_URL Heroku,

heroku addons:add heroku-postgresql:hobby-dev

Sekarang kita semua siap untuk ditempatkan. Tambahkan file kami ke git, komit dan kirim ke heroku

git add .
git commit -m "Heroku deploy"
git push heroku master

Itu saja, aplikasi sudah siap! Pada artikel ini saya menunjukkan betapa mudahnya membuat
aplikasi web kecil menggunakan kerangka kerja Flask dan modul python yang mudah digunakan
untuk enkripsi kriptografi.