Tkn backend

backend/backend_app/gate_backend.py

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+from flask import Flask, request, jsonify
+from web3 import Web3
+import json
+from Crypto.Hash import SHA256
+from Crypto.PublicKey import RSA
+from Crypto.Cipher import PKCS1_OAEP
+
+app = Flask(__name__)
+
+# Connect to School Backend
+SCHOOL_BACKEND_URL = "http://localhost:5001"
+
+# Connect to local Ethereum blockchain (e.g., Ganache)
+w3 = Web3(Web3.HTTPProvider("http://127.0.0.1:7545"))
+
+# Load the contract ABI and address
+with open("ZKACStorageABI.json") as f:
+    contract_abi = json.load(f)
+contract_address = "YOUR_CONTRACT_ADDRESS"
+contract = w3.eth.contract(address=contract_address, abi=contract_abi)
+
+# Gate’s private key for decrypting user data
+gate_private_key = RSA.import_key(open("gate_private_key.pem").read())
+
+def verify_proof(a, s, y, p, g):
+    # Generate the challenge
+    e = int(SHA256.new((str(a) + str(y)).encode()).hexdigest(), 16)
+    # Check if g^s % p == a * y^e % p
+    return pow(g, s, p) == (a * pow(y, e, p)) % p
+
+@app.route('/process_user_entry', methods=['POST'])
+def process_user_entry():
+    data = request.json
+    encrypted_data = bytes.fromhex(data['encrypted_data'])
+
+    # Decrypt data using the gate's private key
+    cipher = PKCS1_OAEP.new(gate_private_key)
+    decrypted_data = cipher.decrypt(encrypted_data).decode().split(',')
+    a, s, y, ID_inv = map(int, decrypted_data)
+
+    # Verify the proof
+    g, p = 2, 23  # Example values for generator and prime
+    if verify_proof(a, s, y, p, g):
+        # Call school backend to validate and invalidate public key
+        response = requests.post(f"{SCHOOL_BACKEND_URL}/invalidate_public_key", json={
+            "public_key": y,
+            "invalidation_id": ID_inv
+        })
+        return response.json()
+    else:
+        return jsonify({"status": "proof_invalid"}), 400
+
+if __name__ == '__main__':
+    app.run(port=5002)

backend/backend_app/school_backend.py

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+from flask import Flask, request, jsonify
+from web3 import Web3
+import json
+import os
+app = Flask(__name__)
+
+# Connect to Ganache or Ethereum node
+
+# Connect to the Ethereum network
+w3 = Web3(Web3.HTTPProvider('https://eth-sepolia.g.alchemy.com/v2/3LAfFWhjVk6bCEvhaSN-QK14ifGQclgp'))
+
+# Load the contract ABI and address
+abi_path = os.path.join(os.path.dirname(__file__), '../smart_contract/zkac_storage_abi.json')
+with open(abi_path) as f:
+    contract_abi = json.load(f)
+contract_address = "0xeeccb8dc5c0f0a1d4aefc7aab5cb6dda4c73fbe6"
+contract = w3.eth.contract(address=contract_address, abi=contract_abi)
+
+# School address
+manager_address = "0xb3ff7fa3992e9325cf47d2af0aca4ba1155b35c7"
+private_key = "3b7041f06f948636c3ccc48dcae30b9fd60ac509d5bb71d5386a7448a86122ab"
+
+@app.route('/invalidate_public_key', methods=['POST'])
+def invalidate_public_key():
+    data = request.json
+    public_key = data['public_key']
+    invalidation_id = data['invalidation_id']
+
+    # Check if public key is valid
+    is_valid = contract.functions.isPublicKeyValid(public_key).call()
+    if not is_valid:
+        return jsonify({"status": "public_key_invalid"}), 400
+
+    # Invalidate the public key on blockchain
+    txn = contract.functions.invalidatePublicKey(public_key).buildTransaction({
+        'from': manager_address,
+        'nonce': w3.eth.get_transaction_count(manager_address),
+        'gas': 2000000,
+        'gasPrice': w3.toWei('20', 'gwei')
+    })
+    signed_txn = w3.eth.account.sign_transaction(txn, private_key=private_key)
+    txn_hash = w3.eth.send_raw_transaction(signed_txn.rawTransaction)
+
+    return jsonify({
+        "status": "public_key_invalidated",
+        "txn_hash": txn_hash.hex(),
+        "public_key": public_key,
+        "invalidation_id": invalidation_id
+    })
+
+@app.route('/update_public_key', methods=['POST'])
+def update_public_key():
+    data = request.json
+    new_public_key = data['new_public_key']
+    old_public_key = data['old_public_key']
+    invalidation_id = data['invalidation_id']
+    signature = data['signature']
+
+    # Verify the signature with the old public key
+    # (Assume we have a function to verify signature)
+
+    # Update public key on the blockchain
+    txn = contract.functions.updatePublicKey(new_public_key).buildTransaction({
+        'from': manager_address,
+        'nonce': w3.eth.get_transaction_count(manager_address),
+        'gas': 2000000,
+        'gasPrice': w3.toWei('20', 'gwei')
+    })
+    signed_txn = w3.eth.account.sign_transaction(txn, private_key=private_key)
+    txn_hash = w3.eth.send_raw_transaction(signed_txn.rawTransaction)
+
+    return jsonify({
+        "status": "public_key_updated",
+        "txn_hash": txn_hash.hex(),
+        "new_public_key": new_public_key
+    })
+
+if __name__ == '__main__':
+    app.run(port=5001)

backend/smart_contract/zkac_storage_abi.json

@@ -0,0 +1,242 @@
+[
+	{
+		"inputs": [
+			{
+				"internalType": "uint256",
+				"name": "_publicKey",
+				"type": "uint256"
+			}
+		],
+		"name": "invalidatePublicKey",
+		"outputs": [],
+		"stateMutability": "nonpayable",
+		"type": "function"
+	},
+	{
+		"inputs": [
+			{
+				"internalType": "uint256[]",
+				"name": "_publicKeys",
+				"type": "uint256[]"
+			}
+		],
+		"name": "invalidatePublicKeyBatch",
+		"outputs": [],
+		"stateMutability": "nonpayable",
+		"type": "function"
+	},
+	{
+		"inputs": [],
+		"stateMutability": "nonpayable",
+		"type": "constructor"
+	},
+	{
+		"anonymous": false,
+		"inputs": [
+			{
+				"indexed": false,
+				"internalType": "address",
+				"name": "smartGate",
+				"type": "address"
+			},
+			{
+				"indexed": false,
+				"internalType": "bytes",
+				"name": "invalidationID",
+				"type": "bytes"
+			}
+		],
+		"name": "InvalidationIDSent",
+		"type": "event"
+	},
+	{
+		"inputs": [
+			{
+				"internalType": "address",
+				"name": "_smartGate",
+				"type": "address"
+			},
+			{
+				"internalType": "bool",
+				"name": "_add",
+				"type": "bool"
+			}
+		],
+		"name": "manageSmartGate",
+		"outputs": [],
+		"stateMutability": "nonpayable",
+		"type": "function"
+	},
+	{
+		"inputs": [
+			{
+				"internalType": "address[]",
+				"name": "_smartGates",
+				"type": "address[]"
+			},
+			{
+				"internalType": "bool",
+				"name": "_add",
+				"type": "bool"
+			}
+		],
+		"name": "manageSmartGateBatch",
+		"outputs": [],
+		"stateMutability": "nonpayable",
+		"type": "function"
+	},
+	{
+		"anonymous": false,
+		"inputs": [
+			{
+				"indexed": false,
+				"internalType": "uint256",
+				"name": "publicKey",
+				"type": "uint256"
+			},
+			{
+				"indexed": false,
+				"internalType": "address",
+				"name": "smartGate",
+				"type": "address"
+			}
+		],
+		"name": "PublicKeyInvalidated",
+		"type": "event"
+	},
+	{
+		"anonymous": false,
+		"inputs": [
+			{
+				"indexed": false,
+				"internalType": "uint256",
+				"name": "newPublicKey",
+				"type": "uint256"
+			}
+		],
+		"name": "PublicKeyUpdated",
+		"type": "event"
+	},
+	{
+		"inputs": [
+			{
+				"internalType": "bytes",
+				"name": "enc_invalidationID",
+				"type": "bytes"
+			}
+		],
+		"name": "sendInvalidationID",
+		"outputs": [],
+		"stateMutability": "nonpayable",
+		"type": "function"
+	},
+	{
+		"inputs": [
+			{
+				"internalType": "bytes[]",
+				"name": "enc_invalidationIDs",
+				"type": "bytes[]"
+			}
+		],
+		"name": "sendInvalidationIDBatch",
+		"outputs": [],
+		"stateMutability": "nonpayable",
+		"type": "function"
+	},
+	{
+		"inputs": [
+			{
+				"internalType": "uint256",
+				"name": "_newPublicKey",
+				"type": "uint256"
+			}
+		],
+		"name": "updatePublicKey",
+		"outputs": [],
+		"stateMutability": "nonpayable",
+		"type": "function"
+	},
+	{
+		"inputs": [
+			{
+				"internalType": "uint256[]",
+				"name": "_newPublicKeys",
+				"type": "uint256[]"
+			}
+		],
+		"name": "updatePublicKeyBatch",
+		"outputs": [],
+		"stateMutability": "nonpayable",
+		"type": "function"
+	},
+	{
+		"inputs": [
+			{
+				"internalType": "uint256",
+				"name": "_publicKey",
+				"type": "uint256"
+			}
+		],
+		"name": "isPublicKeyValid",
+		"outputs": [
+			{
+				"internalType": "bool",
+				"name": "",
+				"type": "bool"
+			}
+		],
+		"stateMutability": "view",
+		"type": "function"
+	},
+	{
+		"inputs": [],
+		"name": "manager",
+		"outputs": [
+			{
+				"internalType": "address",
+				"name": "",
+				"type": "address"
+			}
+		],
+		"stateMutability": "view",
+		"type": "function"
+	},
+	{
+		"inputs": [
+			{
+				"internalType": "uint256",
+				"name": "",
+				"type": "uint256"
+			}
+		],
+		"name": "publicKeyValid",
+		"outputs": [
+			{
+				"internalType": "bool",
+				"name": "",
+				"type": "bool"
+			}
+		],
+		"stateMutability": "view",
+		"type": "function"
+	},
+	{
+		"inputs": [
+			{
+				"internalType": "address",
+				"name": "",
+				"type": "address"
+			}
+		],
+		"name": "smartGates",
+		"outputs": [
+			{
+				"internalType": "bool",
+				"name": "",
+				"type": "bool"
+			}
+		],
+		"stateMutability": "view",
+		"type": "function"
+	}
+]