Update result.html

.gitignore

@@ -0,0 +1,104 @@
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+.hypothesis/
+.pytest_cache/
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+db.sqlite3
+
+# Flask stuff:
+instance/
+.webassets-cache
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# pyenv
+.python-version
+
+# celery beat schedule file
+celerybeat-schedule
+
+# SageMath parsed files
+*.sage.py
+
+# Environments
+.env
+.venv
+env/
+venv/
+ENV/
+env.bak/
+venv.bak/
+
+# Spyder project settings
+.spyderproject
+.spyproject
+
+# Rope project settings
+.ropeproject
+
+# mkdocs documentation
+/site
+
+# mypy
+.mypy_cache/

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2018 Adeen Shukla
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -1,17 +1,15 @@
 ## E-Attendance using *Blockchain*
+###### Our project implements an E-Attendance system which stores student attendance data on a blockchain.
 ---
 
-Mini Project for the 4th semester of MCA 6 years course
-
+![Gif of workflow](https://media.giphy.com/media/mxnAJxpllD9P80hGND/giphy.gif)
 #### Introduction
 Blockchain is the technology behind cryptocurrencies such as Bitcoin, Ethereum, Litecoin etc.
 
  A blockchain, is a list of records, called blocks, which are linked and secured using cryptography. Each block contains a cryptographic hash of the previous block, a timestamp and transaction data. The data, once entered in a block is immutable due to the way blockchains are designed.
 
 This concept of immutable digital data storage can be used for storing data securely, such as student attendance, medical records, and financial transactions, to prevent tampering with this data.
 
-###### Our project implements an E-Attendance system which stores student attendance data on a blockchain.
-
 #### Disclaimer and assumptions
 
 This project is to be considered as a proof of concept only. As such the basic algorithm behind a blockchain is used which constructs blocks and associates them using their cryptographic hashes. A proof of work or proof of stake algorithm has not been implemented to prevent the need for higher computing resources. Unlike traditional decentralized blockchains, this blockchain works using a centralized flask server to avoid dealing with multiple nodes unnecessarily for now.
@@ -62,14 +60,13 @@ $ pip install requests
 - Open a Terminal
 - Navigate to the root folder of the project.
 ```
-$ cd path/to/MiniProject
+$ cd path/to/Blockendance
 ```
-- Specify the flask application by adding it to the environment variable.
+- Run the python app
 ```
-$ export FLASK_APP=blockchain.py
-```
-- Run the flask app
-```
-$ flask run
+$ python blockchain.py
 ```
 - Open a web browser and navigate to "http://localhost:5000" to use the application.
+
+#### Copyright and License
+Copyright (c) 2018 Adeen Shukla - Released under the MIT License

blockchain.py

@@ -1,92 +1,84 @@
+# Python module imports
 import datetime as dt
 import hashlib
 from flask import Flask, request, render_template, Response
 
-from genesis import create_genesis_block
-from newBlock import next_block
+# Importing local functions
 from block import *
+from genesis import create_genesis_block
+from newBlock import next_block, add_block
+from getBlock import find_records
+from checkChain import check_integrity
 
-# TODO CSS
-
+# Flask declarations
 app = Flask(__name__)
 response = Response()
 response.headers.add('Cache-Control', 'no-store, no-cache, must-revalidate, post-check=0, pre-check=0')
 
+# Initializing blockchain with the genesis block
 blockchain = create_genesis_block()
-previous_block = blockchain[0]
 data = []
 
-def add_block(form):
-    global data
-    global previous_block
-    data.append([])# TODO retrieve correct records
-    i = 1
-    while form.get("roll_no{}".format(i)):
-        data[len(data) - 1].append(form.get("roll_no{}".format(i)))
-        i += 1
-    block_to_add = next_block(previous_block, data)
-    blockchain.append(block_to_add)
-    previous_block = block_to_add
-    print ("Block #{} has been added to the blockchain!".format(block_to_add.index))
-    print ("Hash: {}\n".format(block_to_add.hash))
-    print(data)
-    return "Block #{} has been added to the blockchain!".format(block_to_add.index)
-
-def findRecords(form):
-    for block in blockchain:
-        if block.data[0] == form.get("name"):
-            if block.data[1] == form.get("date"):
-                if block.data[2] == form.get("course"):
-                    if block.data[3] == form.get("year"):
-                        return data[4]
-    return -1
-
+# Default Landing page of the app
 @app.route('/',  methods = ['GET'])
 def index():
     return render_template("index.html")
 
-@app.route('/view.html',  methods = ['GET'])
-def view():
-    return render_template("class.html")
-
-@app.route('/view.html',  methods = ['POST'])
-def show_records():
-    data = findRecords(request.form)
-    if data == -1:
-        return "Records not found"
-    return render_template("view.html",
-                            name = request.form.get("name"),
-                            course = request.form.get("course"),
-                            year = request.form.get("year"),
-                            status = data,
-                            number = int(request.form.get("number")),
-                            date = request.form.get("date"))
-
+# Get Form input and decide what is to be done with it
 @app.route('/', methods = ['POST'])
 def parse_request():
-    global data
     if(request.form.get("name")):
-        data = []
+        while len(data) > 0:
+            data.pop()
         data.append(request.form.get("name"))
         data.append(str(dt.date.today()))
         return render_template("class.html",
                                 name = request.form.get("name"),
                                 date = dt.date.today())
 
     elif(request.form.get("number")):
-        data = data[0:2]
+        while len(data) > 2:
+            data.pop()
         data.append(request.form.get("course"))
         data.append(request.form.get("year"))
         return render_template("attendance.html",
+                                name = data[0],
                                 course = request.form.get("course"),
                                 year = request.form.get("year"),
                                 number = int(request.form.get("number")))
     elif(request.form.get("roll_no1")):
-        data = data[0:4]
-        return render_template("submitted.html", result = add_block(request.form))
+        while len(data) > 4:
+            data.pop()
+        return render_template("result.html", result = add_block(request.form, data, blockchain))
 
     else:
         return "Invalid POST request. This incident has been recorded."
 
+# Show page to get information for fetching records
+@app.route('/view.html',  methods = ['GET'])
+def view():
+    return render_template("class.html")
+
+# Process form input for fetching records from the blockchain
+@app.route('/view.html',  methods = ['POST'])
+def show_records():
+    data = []
+    data = find_records(request.form, blockchain)
+    if data == -1:
+        return "Records not found"
+    return render_template("view.html",
+                            name = request.form.get("name"),
+                            course = request.form.get("course"),
+                            year = request.form.get("year"),
+                            status = data,
+                            number = int(request.form.get("number")),
+                            date = request.form.get("date"))
+
+# Show page with result of checking blockchain integrity
+@app.route('/result.html',  methods = ['GET'])
+def check():
+    return render_template("result.html", result = check_integrity(blockchain))
+
+# Start the flask app when program is executed
 if __name__ == "__main__":
-    main()
+    app.run()

checkChain.py

@@ -0,0 +1,8 @@
+def check_integrity(chain):
+    for i, block in enumerate(chain):
+        if i < len(chain) - 1:
+            print("Checking integrity of block {}".format(i))
+            if block.hash_block() != chain[i+1].prev_hash:
+                return ("Chain has been modified at block index {}".format(i))
+        else:
+            return ("Chain has not been modified")

getBlock.py

@@ -0,0 +1,11 @@
+def find_records(form, blockchain):
+    for block in blockchain:
+        print(block.data)
+        condition = (block.data[0] == form.get("name") and
+                    block.data[1] == form.get("date") and
+                    block.data[2] == form.get("course") and
+                    block.data[3] == form.get("year") and
+                    len(block.data[4]) == int(form.get("number")))
+        if condition:
+            return block.data[4]
+    return -1

newBlock.py

@@ -4,6 +4,21 @@
 def next_block(last_block, data):
     this_index = last_block.index + 1
     this_timestamp = dt.datetime.now()
-    this_data = data
+    # A one level deep copy of data has been created since data is modified repeatedly
+    # in the calling function and if data is a direct pointer, it leads to modification
+    # of old data in the chain.
+    this_data = data[:]
     this_prev_hash = last_block.hash
     return Block(this_index, this_timestamp, this_data, this_prev_hash)
+
+def add_block(form, data, blockchain):
+    data.append([])
+    i = 1
+    while form.get("roll_no{}".format(i)):
+        data[-1].append(form.get("roll_no{}".format(i)))
+        i += 1
+    previous_block = blockchain[-1]
+    block_to_add = next_block(previous_block, data)
+    blockchain.append(block_to_add)
+    previous_block = block_to_add
+    return "Block #{} has been added to the blockchain!".format(block_to_add.index)

static/LICENSE

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2014-2018 Materialize
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

static/css/main.css

@@ -0,0 +1,5 @@
+body {
+    max-width: 500px;
+    margin: auto;
+    padding-top: 50px;
+}