d3gymiz7

1"""
2Document Validator
3
4This code allows you to upload documents and later check whether they have been modified.
5
6This tool accepts .txt files.-
7
8Technologies used are flask, flask_mail, sha256, IPFS and sqlite
9"""
10
11from flask import Flask, render_template, request, send_file
12from flask_mail import Mail, Message
13from hashlib import sha256
14from sqlite3 import connect
15from io import BytesIO
16import random
17import ipfshttpclient
18
19# Create Flask app
20app = Flask(__name__)
21
22# Configure the app
23app.config["TEMPLATES_AUTO_RELOAD"] = True
24email = "YOUR_USERNAME"
25password = "YOUR_PASSWORD"
26mail_settings = {
27    "MAIL_SERVER": "smtp.gmail.com",
28    "MAIL_PORT": 465,
29    "MAIL_USE_TLS": False,
30    "MAIL_USE_SSL": True,
31    "MAIL_USERNAME": email,
32    "MAIL_PASSWORD": password
33}
34app.config.update(mail_settings)
35
36# Create the mail and link it to flask
37mail = Mail(app)
38
39# Create IPFS client
40client = ipfshttpclient.connect("/ip4/127.0.0.1/tcp/5001")
41
42# Connect to sqlite
43connection = connect("C:\\Users\\Dhruv\\PycharmProjects\\DocumentValidation\\documents.db", check_same_thread=False)
44cursor = connection.cursor()
45
46# Create table if not already created
47table = '''CREATE TABLE IF NOT EXISTS Documents
48                (ID VARCHAR(16) PRIMARY KEY,
49                 HASH VARCHAR(64))'''
50cursor.execute(table)
51
52
53@app.route("/")
54def index():
55    """ Ask the user to enter the document """
56    return render_template("index.html")
57
58
59@app.route("/send_mail", methods=["GET", "POST"])
60def send_mail():
61    """ Send mail with the content accepted from the form """
62
63    if request.method == "POST":
64
65        # Get all parameters from the form
66        sender = request.form.get("sender")
67        recipient = request.form.get("recipient")
68        subject = request.form.get("subject")
69        content = request.form["content"]
70        file = request.files["file"]
71
72        # Generate id for the inputted document
73        key = ''.join(random.choice('0123456789ABCDEF') for i in range(16))
74
75        # Make sure key is unique
76        while True:
77            command = "SELECT * FROM Documents WHERE ID = '{}'".format(key)
78            cursor.execute(command)
79            result = cursor.fetchall()
80            if not result:
81                break
82            key = ''.join(random.choice('0123456789ABCDEF') for i in range(16))
83
84        # Upload the file to IPFS
85        ipfs_hash = client.add_bytes(file.read())
86
87        # Create the body of the mail
88        html = 'Sender : {} <br><br> {} <br><br> <a href="http://127.0.0.1:5000/verify?id={}">Verification Link</a> ' \
89               '<br><br> <a href="http://127.0.0.1:5000/download?key={}">Download link</a>'\
90            .format(sender, content, key, ipfs_hash)
91
92        # Store the hashcode in the table
93        file.seek(0)
94        hashcode = sha256(file.read()).hexdigest()
95        command = "INSERT INTO Documents (ID, HASH) VALUES ('{}', '{}')".format(key, hashcode)
96        cursor.execute(command)
97        connection.commit()
98
99        # Send the mail
100        with app.app_context():
101            # Create the message to be sent
102            message = Message(
103                subject=subject,
104                sender=app.config.get("MAIL_USERNAME"),
105                recipients=[recipient],
106                html=html
107            )
108
109            # Attach the file to it
110            file.seek(0)
111            message.attach("file.txt", "text/plain", file.read())
112
113            mail.send(message)
114
115        # Success
116        return render_template("success.html", code="The mail has been sent")
117
118    else:
119        # Access via post request
120        return render_template("index.html")
121
122
123@app.route("/verify", methods=["GET", "POST"])
124def verify():
125    """ Ask the user to upload the document to be verified """
126    return render_template("upload.html", url="/validate?id={}".format(request.args.get("id")))
127
128
129@app.route("/validate", methods=["GET", "POST"])
130def validate():
131    """ Display whether the document has been modified"""
132
133    if request.method == "POST":
134
135        # Get the required fields from the form and the url
136        file = request.files["file"]
137        key = request.args.get("id")
138
139        # Check all fields are present
140        if not key or not file:
141            return render_template("apology.html", code="All fields are not present")
142
143        # Query database
144        hashcode = sha256(file.read()).hexdigest()
145        command = "SELECT * FROM Documents WHERE ID = '{}' AND HASH = '{}'".format(key, hashcode)
146        cursor.execute(command)
147        result = cursor.fetchall()
148
149        # Display whether the document was tampered or not
150        if not result:
151            return render_template("success.html", code="The document has been modified")
152        else:
153            return render_template("success.html", code="The document has not been modified")
154
155    else:
156        return verify()
157
158
159@app.route("/download", methods=["GET", "POST"])
160def download():
161    """Get the required file from IPFS and send it to the user"""
162    key = request.args.get("key")
163
164    # Check key field has been provided
165    if not key:
166        return render_template("apology.html", code="The URL provided is incorrect")
167
168    # Check hash is correct
169    try:
170        byte = client.cat(key)
171    except ipfshttpclient.exceptions.ErrorResponse:
172        return render_template("apology.html", code="The URL provided is incorrect")
173
174    # Write the bytes to a file
175    file = BytesIO()
176    file.write(byte)
177    file.seek(0)
178
179    # Send the file to the user
180    return send_file(file, attachment_filename="file.txt", as_attachment=True)
181
182
183# Run the app
184if __name__ == "__main__":
185    app.run(
186        debug=True
187    )