mistake ex3

period_1/04-blockchain_class/405_HW3_Tamper-Proof_Chain/BlockChain.py

@@ -63,6 +63,12 @@ class CBlock:
     # Make sure to compute the hash value of the current block and store it properly 
     def mine(self, leading_zeros):
         self.nonce = 0
+
+        if self.previousBlock:
+            self.previousHash = self.previousBlock.blockHash
+        else:
+            self.previousHash = None
+            
         while True:
             digest = self.computeHash()
 
@@ -72,15 +78,23 @@ class CBlock:
                 break
 
             self.nonce += 1        
-    
+
     # TODO 4: Check if the current block contains valid hash digest values 
     # Make sure to distinguish between the genesis block and other blocks
     # Make sure to compare both hash digest values:
     # The computed digest of the current block
     # The stored digest of the previous block
     # return the result of all comparisons as a boolean value 
+    # def is_valid_hash(self):
+    #     if(self.previousBlock == None):
+    #         return True
+             
+    #     if(self.computeHash() != self.blockHash or self.previousBlock.blockHash != self.previousBlock.computeHash()):
+    #         return False
+    #     return self.previousBlock.is_valid_hash()
+
     def is_valid_hash(self):
-        if self.previousBlock == None:
-            return True
-        
+        if self.previousBlock:
+            self.previousHash = self.previousBlock.computeHash()
+
         return self.computeHash() == self.blockHash