Create consensus_algorithm.py

projects/DAPIO/oracle-node/consensus/consensus_algorithm.py

@@ -0,0 +1,37 @@
+import hashlib
+import time
+from cryptography.hazmat.primitives import serialization
+from cryptography.hazmat.primitives.asymmetric import ec
+from cryptography.hazmat.backends import default_backend
+
+class ConsensusAlgorithm:
+    def __init__(self, nodes: list, threshold: int):
+        self.nodes = nodes
+        self.threshold = threshold
+        self.public_keys = [serialization.load_pem_public_key(node.encode(), backend=default_backend()) for node in nodes]
+
+    def propose_block(self, block: dict) -> bytes:
+        proposal = json.dumps(block).encode()
+        signature = ec.ECDSA(self.public_keys[0]).sign(proposal, hashlib.sha256(proposal).digest())
+        return proposal + signature
+
+    def verify_proposal(self, proposal: bytes) -> bool:
+        proposal_data, signature = proposal[:-64], proposal[-64:]
+        for public_key in self.public_keys:
+            try:
+                ec.ECDSA(public_key).verify(signature, hashlib.sha256(proposal_data).digest())
+                return True
+            except:
+                pass
+        return False
+
+    def finalize_block(self, block: dict) -> bytes:
+        finalized_block = json.dumps(block).encode()
+        return finalized_block
+
+    def run_consensus(self) -> bytes:
+        while True:
+            proposal = self.propose_block({"data": "example_data"})
+            if self.verify_proposal(proposal):
+                return self.finalize_block({"data": "example_data"})
+            time.sleep(1)