wip > laptop to pc

goodchain/src/classes/Blockchain.py

@@ -0,0 +1,25 @@
+from cryptography.hazmat.backends import default_backend
+from cryptography.hazmat.primitives import hashes
+
+class CBlock:
+
+    data = None
+    previousHash = None
+    previousBlock = None
+    def __init__(self, data, previousBlock):
+        self.data = data
+        self.blockHash = None
+        self.previousBlock = previousBlock
+        if previousBlock != None:
+            self.previousHash = previousBlock.computeHash()
+    
+    def computeHash(self):
+        digest = hashes.Hash(hashes.SHA256(), backend=default_backend())
+        digest.update(bytes(str(self.data),'utf8'))
+        digest.update(bytes(str(self.previousHash),'utf8'))
+        return digest.finalize()
+
+    def is_valid(self):
+        if self.previousBlock == None:
+            return True
+        return self.previousBlock.computeHash() == self.previousHash

goodchain/src/classes/Transaction.py

@@ -0,0 +1,110 @@
+MINE_REWARD_VALUE = 25.0
+REGISTRATION_REWARD_VALUE = 50.0
+NORMAL = 0
+REWARD = 1
+
+from helpers import SignatureHelper as Signature
+
+class Tx:
+    def __init__(self, type = NORMAL):
+        
+        self.type = type
+        self.inputs = []
+        self.outputs = []
+        self.sigs = []
+        self.reqd = []
+
+    def add_input(self, from_addr, amount):
+        self.inputs.append((from_addr, amount))
+
+    def add_output(self, to_addr, amount):
+        self.outputs.append((to_addr, amount))
+
+    def add_reqd(self, addr):
+        self.reqd.append(addr)
+
+    def sign(self, private):
+        message = self.__gather()
+        newsig = Signature.sign(message, private)
+        self.sigs.append(newsig)
+               
+    def is_valid(self):
+
+        if self.type == REWARD:
+            if len(self.inputs)!=0 and len(self.outputs)!=1:
+                return False
+            return True
+        
+        else:
+            total_in = 0
+            total_out = 0
+            message = self.__gather()
+            for addr,amount in self.inputs:
+                found = False
+                for s in self.sigs:
+                    if Signature.verify(message, s, addr):
+                        found = True
+                if not found:
+                    return False
+                if amount < 0:
+                    return False
+                total_in = total_in + amount
+            for addr in self.reqd:
+                found = False
+                for s in self.sigs:
+                    if Signature.verify(message, s, addr):
+                        found = True
+                if not found:
+                    return False
+            for addr,amount in self.outputs:
+                if amount < 0:
+                    return False
+                total_out = total_out + amount
+
+            if total_out > total_in:
+                return False        
+            return True
+
+    def __gather(self):
+        data=[]
+        data.append(self.inputs)
+        data.append(self.outputs)
+        data.append(self.reqd)
+        return data
+
+    def __repr__(self):
+
+        repr_str = "INPUTS:\n"
+        for addr, amt in self.inputs:
+            repr_str = repr_str + str(amt) + "from" + str(addr) + "\n"
+
+        repr_str += "OUTPUTS:\n"
+        for addr, amt in self.outputs:
+            repr_str = repr_str + str(amt) + "to" + str(addr) + "\n"
+
+        repr_str += "EXTRA REQUIRED SIGNATURES:\n"     
+        for req_sig in self.reqd:
+            repr_str = repr_str + str(req_sig) + "\n"
+
+        repr_str += "SIGNATURES:\n"     
+        for sig in self.sigs:
+            repr_str = repr_str + str(sig) + "\n"
+
+        repr_str += "END\n"
+        
+        return repr_str
+    
+    def createTransaction(self, public_key, private_key, amount, fee, recipient, reqd = None, type = NORMAL):
+        self.add_input(public_key, amount + fee)
+        self.add_output(recipient, amount)
+        self.type = type
+        if reqd != None:
+            self.add_reqd(reqd)
+        self.sign(private_key)
+
+    def createRewardTransaction(self, public_key, private_key, type):
+        value = type == "mine" and MINE_REWARD_VALUE or REGISTRATION_REWARD_VALUE
+        self.add_output(public_key, value)
+        self.type = REWARD
+        self.sign(private_key)
+

goodchain/src/classes/TxBlock.py

@@ -0,0 +1,59 @@
+from classes.Blockchain import CBlock
+from helpers.SignatureHelper import *
+from cryptography.hazmat.primitives import hashes
+from cryptography.hazmat.backends import default_backend
+
+import random
+
+REWARD_VALUE = 25.0
+leading_zeros = 2
+next_char_limit = 20
+
+class TxBlock (CBlock):
+
+    def __init__(self, previousBlock):
+        self.nonce = "A random nonce"
+        super(TxBlock, self).__init__([], previousBlock)
+
+    def addTx(self, Tx_in):
+        self.data.append(Tx_in)
+
+    def __count_totals(self):
+        total_in = 0
+        total_out = 0
+        for tx in self.data:
+            for addr, amt in tx.inputs:
+                total_in = total_in + amt
+            for addr, amt in tx.outputs:
+                total_out = total_out + amt
+        return total_in, total_out
+
+    def is_valid(self):
+        if not super(TxBlock, self).is_valid():
+            return False
+        for tx in self.data:
+            if not tx.is_valid():
+                return False
+        
+        total_in, total_out = self.__count_totals()
+        
+        Tx_Balance = round(total_out - total_in, 10)
+        
+        if  Tx_Balance > REWARD_VALUE:
+            return False
+        return True
+
+    def good_nonce(self):
+        digest = hashes.Hash(hashes.SHA256(), backend=default_backend())
+        digest.update(bytes(str(self.data), 'utf8'))
+        digest.update(bytes(str(self.previousHash), 'utf8'))
+        digest.update(bytes(str(self.nonce), 'utf8'))
+        this_hash = digest.finalize()
+        return this_hash[:leading_zeros] == b'\x00'*leading_zeros
+
+    def find_nonce(self):
+        for i in range(10000000):
+            self.nonce = i
+            if self.good_nonce():
+                return self.nonce
+        return None

goodchain/src/helpers/LoggerHelper.py

@@ -1 +0,0 @@
-# Not sure if we're planning to log anything tho

goodchain/src/helpers/MenuHelper.py

@@ -1,6 +1,10 @@
 import os
 
 from classes.User import User
+from classes.Transaction import Tx
+from helpers import BlockHelper as blockHelper
+from helpers import TaskHelper as taskHelper
+from helpers import UtilityHelper as utilityHelper
 
 class bcolors:
     HEADER = '\033[95m'
@@ -131,10 +135,24 @@ class MenuHelper:
 
                 case "Explore the Blockchain":
                     print("TODO")
+                    block = blockHelper.loadBlock()
+                    i = 0
+                    for data in block.data:
+                        
+                        print(f"---------------------------------- Block {str(i)} ----------------------------------")
+                        print(f"Block hash: {data.Inputs[0][1]}")
+                        print(f"----------------------------------------------------------------------------------")
+                        i += 1
 
                 case "Transfer coins":
-                    input("Enter the username of the receiver: ")
-                    print("TODO")
+                    new_tx = taskHelper.transaction(self)
+                    if new_tx.is_valid():
+                        # TODO: add to pool
+                        print("Transaction is valid")
+                        utilityHelper.saveFile("../data/transaction_pool.dat", new_tx)
+                        continue
+                    print("Transaction is invalid")
+
 
                 case "Cancel transaction":
                     print("TODO")

goodchain/src/helpers/SignatureHelper.py

@@ -41,6 +41,12 @@ def bytesToKeys(private_ser, public_ser):
     )
     return private_key, public_key
 
+def publicBytesToKey(public_ser):
+    public_key = serialization.load_pem_public_key(
+        public_ser
+    )
+    return public_key
+
 def sign(message, private_key):
     message = bytes(str(message), 'utf-8')
     signature = private_key.sign(
@@ -50,9 +56,8 @@ def sign(message, private_key):
         )
     return signature
 
-def verify(message, signature, pbc_ser):
+def verify(message, signature, public_key):
     message = bytes(str(message), 'utf-8')
-    public_key = serialization.load_pem_public_key(pbc_ser)
     try:
         public_key.verify(
             signature,

goodchain/src/helpers/TaskHelper.py

@@ -0,0 +1,38 @@
+from classes.Transaction import Tx
+from helpers import SignatureHelper as signatureHelper
+
+def transaction(self):
+    receiver = input("Enter the username of the receiver:")
+    if receiver == "":
+        return False
+
+    receiver_data = self.db.fetchUserByUsername(receiver)
+    if not receiver_data:
+        print("Username not found")
+        return False
+
+    receiver_public_key = signatureHelper.publicBytesToKey(receiver_data[1])
+
+    amount = input("Enter the amount excluding fees:")
+    if amount == "":
+        return False
+
+    try:
+        amount = int(amount)
+    except:
+        print("Wrong input, try again")
+        return False
+
+    fee = input("Enter fee:")
+    if fee == "":
+        return False
+
+    try:
+        fee = int(fee)
+    except:
+        print("Wrong input, try again")
+        return False
+
+    new_tx = Tx()
+    new_tx.createTransaction(self.user.public_key, self.user.private_key, amount, fee, receiver_public_key)
+    return new_tx

goodchain/src/helpers/UtilityHelper.py

@@ -1,6 +1,4 @@
-from cryptography.hazmat.backends import default_backend
-from cryptography.hazmat.primitives import hashes
-
+import pickle
 import hashlib
 
 def computeHash(data):
@@ -8,3 +6,15 @@ def computeHash(data):
     data = str(data).encode()
     hash.update(data)
     return hash.hexdigest()
+
+
+def saveFile(fileloc, data):
+    savefile = open(fileloc, "wb")
+    pickle.dump(data, savefile)
+    savefile.close()
+
+def loadFile(fileloc):
+    loadfile = open(fileloc ,"rb")
+    load = pickle.load(loadfile)
+    loadfile.close()
+    return load