Initial commit

Author: johnathanmiller

.gitignore

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+.DS_Store

blockchain.py

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+# Blockchain
+
+import datetime
+import hashlib
+import json
+from flask import Flask, jsonify
+
+class Blockchain:
+    
+    def __init__(self):
+        self.chain = []
+        self.create_block(proof = 1, previous_hash = '0')
+        
+    def create_block(self, proof, previous_hash):
+        block = {
+            'index': len(self.chain) + 1,
+            'timestamp': str(datetime.datetime.now()),
+            'proof': proof,
+            'previous_hash': previous_hash
+        }
+        self.chain.append(block)
+        return block
+    
+    def get_previous_block(self):
+        return self.chain[-1]
+    
+    def proof_of_work(self, previous_proof):
+        new_proof = 1
+        check_proof = False
+        while check_proof is False:
+            hash_operation = hashlib.sha256(str(new_proof**2 - previous_proof**2).encode()).hexdigest()
+            if hash_operation[:4] == '0000':
+                check_proof = True
+            else:
+                new_proof += 1
+        return new_proof
+    
+    def hash(self, block):
+        encoded_block = json.dumps(block, sort_keys = True).encode()
+        return hashlib.sha256(encoded_block).hexdigest()
+    
+    def is_chain_valid(self, chain):
+        previous_block = chain[0]
+        block_index = 1
+        while block_index < len(chain):
+            block = chain[block_index]
+            if block['previous_hash'] != self.hash(previous_block):
+                return False
+            previous_proof = previous_block['proof']
+            proof = block['proof']
+            hash_operation = hashlib.sha256(str(proof**2 - previous_proof**2).encode()).hexdigest()
+            if hash_operation[:4] != '0000':
+                return False
+            previous_block = block
+            block_index += 1
+        return True
+    
+# Web app
+app = Flask(__name__)
+
+# Create Blockchain
+blockchain = Blockchain()
+
+# Mine new block
+@app.route('/mine', methods=['GET'])
+def mine_block():
+    previous_block = blockchain.get_previous_block()
+    previous_proof = previous_block['proof']
+    proof = blockchain.proof_of_work(previous_proof)
+    previous_hash = blockchain.hash(previous_block)
+    block = blockchain.create_block(proof, previous_hash)
+    response = {
+        'message': 'Block mined',
+        'index': block['index'],
+        'timestamp': block['timestamp'],
+        'proof': block['proof'],
+        'previous_hash': block['previous_hash']
+    }
+    return jsonify(response), 200
+
+# Get full chain
+@app.route('/blockchain', methods=['GET'])
+def get_blockchain():
+    response = {
+        'length': len(blockchain.chain),
+        'chain': blockchain.chain
+    }
+    return jsonify(response), 200
+
+# Check if blockchain is valid
+@app.route('/blockchain/valid', methods=['GET'])
+def is_valid():
+    is_valid = blockchain.is_chain_valid(blockchain.chain)
+    if is_valid:
+        response = {
+            'message': 'Blockchain is valid'
+        }
+    else:
+        response = {
+            'message': 'Blockchain is NOT valid'
+        }
+    return jsonify(response), 200
+
+# Run the app
+app.run(host = '0.0.0.0', port = 5000)

requirements.txt

@@ -0,0 +1,177 @@
+alabaster==0.7.10
+anaconda-client==1.6.9
+anaconda-navigator==1.7.0
+anaconda-project==0.8.2
+appnope==0.1.0
+appscript==1.0.1
+asn1crypto==0.24.0
+astroid==1.6.1
+astropy==2.0.3
+attrs==17.4.0
+Babel==2.5.3
+backports.shutil-get-terminal-size==1.0.0
+beautifulsoup4==4.6.0
+bitarray==0.8.1
+bkcharts==0.2
+blaze==0.11.3
+bleach==2.1.2
+bokeh==0.12.13
+boto==2.48.0
+Bottleneck==1.2.1
+certifi==2018.1.18
+cffi==1.11.4
+chardet==3.0.4
+click==6.7
+cloudpickle==0.5.2
+clyent==1.2.2
+colorama==0.3.9
+conda==4.4.10
+conda-build==3.4.1
+conda-verify==2.0.0
+contextlib2==0.5.5
+cryptography==2.1.4
+cycler==0.10.0
+Cython==0.27.3
+cytoolz==0.9.0
+dask==0.16.1
+datashape==0.5.4
+decorator==4.2.1
+distributed==1.20.2
+docutils==0.14
+entrypoints==0.2.3
+et-xmlfile==1.0.1
+fastcache==1.0.2
+filelock==2.0.13
+Flask==0.12.2
+Flask-Cors==3.0.3
+gevent==1.2.2
+glob2==0.6
+gmpy2==2.0.8
+greenlet==0.4.12
+h5py==2.7.1
+heapdict==1.0.0
+html5lib==1.0.1
+idna==2.6
+imageio==2.2.0
+imagesize==0.7.1
+ipykernel==4.8.0
+ipython==6.2.1
+ipython-genutils==0.2.0
+ipywidgets==7.1.1
+isort==4.2.15
+itsdangerous==0.24
+jdcal==1.3
+jedi==0.11.1
+Jinja2==2.10
+jsonschema==2.6.0
+jupyter==1.0.0
+jupyter-client==5.2.2
+jupyter-console==5.2.0
+jupyter-core==4.4.0
+jupyterlab==0.31.5
+jupyterlab-launcher==0.10.2
+lazy-object-proxy==1.3.1
+llvmlite==0.21.0
+locket==0.2.0
+lxml==4.1.1
+MarkupSafe==1.0
+matplotlib==2.1.2
+mccabe==0.6.1
+mistune==0.8.3
+mpmath==1.0.0
+msgpack-python==0.5.1
+multipledispatch==0.4.9
+navigator-updater==0.1.0
+nbconvert==5.3.1
+nbformat==4.4.0
+networkx==2.1
+nltk==3.2.5
+nose==1.3.7
+notebook==5.4.0
+numba==0.36.2
+numexpr==2.6.4
+numpy==1.14.0
+numpydoc==0.7.0
+odo==0.5.1
+olefile==0.45.1
+openpyxl==2.4.10
+packaging==16.8
+pandas==0.22.0
+pandocfilters==1.4.2
+parso==0.1.1
+partd==0.3.8
+path.py==10.5
+pathlib2==2.3.0
+patsy==0.5.0
+pep8==1.7.1
+pexpect==4.3.1
+pickleshare==0.7.4
+Pillow==5.0.0
+pkginfo==1.4.1
+pluggy==0.6.0
+ply==3.10
+prompt-toolkit==1.0.15
+psutil==5.4.3
+ptyprocess==0.5.2
+py==1.5.2
+pycodestyle==2.3.1
+pycosat==0.6.3
+pycparser==2.18
+pycrypto==2.6.1
+pycurl==7.43.0.1
+pyflakes==1.6.0
+Pygments==2.2.0
+pylint==1.8.2
+pyodbc==4.0.22
+pyOpenSSL==17.5.0
+pyparsing==2.2.0
+PySocks==1.6.7
+pytest==3.3.2
+python-dateutil==2.6.1
+pytz==2017.3
+PyWavelets==0.5.2
+PyYAML==3.12
+pyzmq==16.0.3
+QtAwesome==0.4.4
+qtconsole==4.3.1
+QtPy==1.3.1
+requests==2.18.4
+rope==0.10.7
+ruamel-yaml==0.15.35
+scikit-image==0.13.1
+scikit-learn==0.19.1
+scipy==1.0.0
+seaborn==0.8.1
+Send2Trash==1.4.2
+simplegeneric==0.8.1
+singledispatch==3.4.0.3
+six==1.11.0
+snowballstemmer==1.2.1
+sortedcollections==0.5.3
+sortedcontainers==1.5.9
+Sphinx==1.6.6
+sphinxcontrib-websupport==1.0.1
+spyder==3.2.6
+SQLAlchemy==1.2.1
+statsmodels==0.8.0
+sympy==1.1.1
+tables==3.4.2
+tblib==1.3.2
+terminado==0.8.1
+testpath==0.3.1
+toolz==0.9.0
+tornado==4.5.3
+traitlets==4.3.2
+typing==3.6.2
+unicodecsv==0.14.1
+urllib3==1.22
+wcwidth==0.1.7
+webencodings==0.5.1
+Werkzeug==0.14.1
+widgetsnbextension==3.1.0
+wrapt==1.10.11
+xlrd==1.1.0
+XlsxWriter==1.0.2
+xlwings==0.11.5
+xlwt==1.2.0
+zict==0.1.3