def DHencrypt(plaintext, symmetricKey, p, gen):
"""Encrypts a message M given parameters above"""
"Method was updated to use AES symetric decryption that was"
"provided in the starter code as option of symetric encrytion using shared secret keys is generated."
simplified_AES.keyExp(symmetricKey) # Generating round keys for AES.
ciphertext = simplified_AES.encrypt(plaintext) # Running simplified AES.
return ciphertext
def main():
"""Driver function for the project"""
serverHost = 'localhost' # The remote host
serverPort = 9000 # The same port as used by the server
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((serverHost, serverPort))
msg = serverHello()
s.sendall(bytes(msg,'utf-8')) # Sending bytes encoded in utf-8 format.
data = s.recv(1024).decode('utf-8')
strStatus = "105 Hello"
if data and data.find(strStatus) < 0:
print("Invalid data received. Closing")
else:
# Write appropriate code to parse received string and extract
# the modulus and exponent for public key encryption.
values = data[10:].split()
n = int(values[0])# Modulus for public key encryption
e = int(values[1]) # Exponent for public key encryption
print("Server's public key: ("+ str(n)+","+str(e)+")")
symmetricKey = computeSessionKey()
print("Computed symmetricKey: ", symmetricKey)
encSymmKey = RSAencrypt(symmetricKey, e, n)
print("Encrypted symmetricKey: ", encSymmKey)
msg = sendSessionKey(encSymmKey)
s.sendall(bytes(msg,'utf-8'))
data = s.recv(1024).decode('utf-8')
strStatus = "113 Nonce"
if data and data.find(strStatus) < 0:
print("Invalid data received. Closing")
else:
# Write code to parse received string and extract encrypted nonce
encNonce = int(data[10:])
# from the server. The nonce has been encrypted with the server's
# private key.
print("Encrypted nonce: "+ str(encNonce))
nonce = RSAdecrypt(encNonce, e, n)
print("Decrypted nonce: "+ str(nonce))
"""Setting up for Simplified AES encryption"""
plaintext = nonce
print("plaintext: ", plaintext)
simplified_AES.keyExp(symmetricKey) # Generating round keys for AES.
ciphertext = simplified_AES.encrypt(plaintext) # Running simplified AES.
print("ciphertext: ", ciphertext)
msg = sendTransformedNonce(ciphertext)
s.sendall(bytes(msg,'utf-8'))
data = s.recv(1024).decode('utf-8')
if data:
print(data)
s.close()
def main():
"""Driver function for the project"""
HOST = 'localhost' # The remote host
PORT = 13000 # The same port as used by the server
c = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
c.connect((HOST,PORT))
msg = serverHello()
c.sendall(bytes(msg,'utf-8')) # Sending bytes encoded in utf-8 format.
data = c.recv(1024).decode('utf-8')
strStatus = "105 Hello"
if data and data.find(strStatus) < 0:
print("Invalid data received. Closing")
else:
# Write appropriate code to parse received string and extract
# the modulus and exponent for public key encryption.
splitd = data.split(" ")
n = int(splitd[2])# Modulus for public key encryption
e = int(splitd[3]) # Exponent for public key encryption
print("Server's public key: ("+ str(n)+","+str(e)+")")
symmetricKey = computeSessionKey()
print("the generated symm key is ",symmetricKey)
simplified_AES.keyExp(symmetricKey)
encSymmKey = RSAencrypt(symmetricKey, e, n)
print("encrypted symm key ",encSymmKey)
msg = sendSessionKey(encSymmKey)
c.sendall(bytes(msg,'utf-8'))
data = c.recv(1024).decode('utf-8')
strStatus = "113 Nonce"
if data and data.find(strStatus) < 0:
print("Invalid data received. Closing")
else:
# Write code to parse received string and extract encrypted nonce
splitd = data.split(" ")
encNonce = int(splitd[2])
# from the server. The nonce has been encrypted with the server's
# private key.
print("Encrypted nonce: "+ str(encNonce))
temp = RSAencrypt(encNonce, e, n)
plaintext = temp
print("Decrypted nonce: "+ str(temp))
"""Setting up for Simplified AES encryption"""
simplified_AES.keyExp(symmetricKey) # Generating round keys for AES.
ciphertext = simplified_AES.encrypt(plaintext) # Running simplified AES.
msg = sendTransformedNonce(ciphertext)
c.sendall(bytes(msg,'utf-8'))
data = c.recv(1024).decode('utf-8')
if data:
print(data)
c.close()
def processMsgs(s, msg, state):
"""This function processes messages that are read through the socket. It
returns a status, which is an integer indicating whether the operation
was successful"""
status = -2
rcvr_mod = int(state['modulus']) # Receiver's modulus for RSA
rcvr_exp = int(state['pub_exp']) # Receiver's public exponent
symmetricKey = int(state['SymmetricKey']) # shared symmetric key
bids = int(state['Bids']) # bids = number of bids made
DiceValues = state['Dice'] # DiceValues = values of dice
dice = list(map(int,dice)) # Converting dice values to ints
strTest = "101 Hello "
if (strTest in msg and status==-2):
RcvdStr = msg.split(' ')
sndr_mod = int(RcvdStr[2]) # Modulus for public key encryption
sndr_exp = int(RcvdStr[3]) # Exponent for public key encryption
symmetricKey = computeSessionKey()
## Add code to handle the case where the symmetricKey is
## greater than the modulus.
encSymmKey = ## Add code to encrypt the symmetric key.
msg = sendSessionKey(encSymmKey)
s.sendall(bytes(msg,'utf-8'))
state['modulus'] = sndr_mod
state['pub_exp'] = sndr_exp
state['SymmetricKey'] = symmetricKey
status = 1
strNonce = "120 Nonce"
if (strNonce in msg and status==-2):
RcvdStr = msg.split(' ')
encNonce = int(RcvdStr[2])
nonce = ## Add code to decrypt nonce
"""Setting up for Simplified AES encryption"""
plaintext = nonce
simplified_AES.keyExp(symmetricKey) # Generating round keys for AES.
ciphertext = simplified_AES.encrypt(plaintext) # Running simplified AES.
msg = sendTransformedNonce(ciphertext)
s.sendall(bytes(msg,'utf-8'))
status = 1
def main():
"""Driver function for the project"""
serverHost = 'localhost' # The remote host
serverPort = 9000 # The same port as used by the server
print "Creating socket to communicate with remote host @ " + str(
serverHost) + " over port " + str(serverPort)
serverSocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print "Connecting to remote host..."
try:
serverSocket.connect((serverHost, serverPort))
except socket.error as e:
print ""
print "Failed to establish connection to remote host with error:"
print "\t" + str(e)
print "Program will end now."
return 1
print "Connected."
print ""
print "Sending hello message to remote host..."
try:
serverSocket.sendall(serverHello())
except socket.error:
print ""
print "Error sending data to remote host"
return 1
print "Hello message sent."
print ""
print "Waiting on server to send its public key..."
buff = serverSocket.recv(1024)
if not buff:
handleRemoteHostDisappear(serverSocket)
return 0
strStatus = "105 Hello"
if buff.find(strStatus) >= 0:
print "Public key received."
print "Parsing response..."
data = buff.split(" ")
n = int(data[2]) # Modulus for public key encryption
e = int(data[3]) # Exponent for public key encryption
print "Server's public key: (" + str(n) + ", " + str(e) + ")"
print ""
print "Generating this client's keys..."
# I don't need to assume. I KNOW that these numbers will fall in the same ranges like in the server and be prime :P
p_client = random.randint(907, 1014)
while not isPrime(p_client): # keep going til we're prime
p_client = random.randint(907, 1014)
q_client = random.randint(53, 68)
while not isPrime(q_client):
q_client = random.randint(53, 68)
n_client, e_client, d_client = genKeys(p_client, q_client)
print "Client's public key: (" + str(n_client) + ", " + str(
e_client) + ")"
print "Sending public key to server..."
try:
serverSocket.sendall("110 PB " + str(n_client) + " " +
str(e_client))
except socket.error:
print ""
print "Error sending data to server"
return 1
print "Public key sent."
print ""
else:
handleProtocolError(buff, serverSocket)
return 0
print "Waiting on server's receipt ack..."
buff = serverSocket.recv(1024)
if not buff:
handleRemoteHostDisappear(serverSocket)
return 0
if buff == "111 ACK PB":
print "Received receipt ack."
print ""
print "Generating session key..."
symmetricKey = computeSessionKey()
encSymmKey = RSAencrypt(symmetricKey, e, n)
print "Session key generated."
msg = sendSessionKey(encSymmKey)
print "Pending message to server:"
print "\t" + str(msg)
print "Sending..."
try:
serverSocket.sendall(msg)
except socket.error:
print ""
print "Error sending data to server"
return 1
print "Session key sent."
print ""
else:
handleProtocolError(buff, serverSocket)
return 0
print "Waiting on server challenge..."
buff = serverSocket.recv(1024)
if not buff:
handleRemoteHostDisappear(serverSocket)
return 0
strStatus = "113 Nonce"
if buff.find(strStatus) >= 0:
print "Challenge received."
encNonce = int(buff.split(" ")[2])
print "Encrypted nonce: " + str(encNonce)
print "Decrypting nonce..."
nonce = RSAdecrypt(encNonce, e, n)
print "Decrypted nonce: " + str(nonce)
print ""
"""Setting up for Simplified AES encryption"""
plaintext = nonce
simplified_AES.keyExp(symmetricKey) # Generating round keys for AES.
ciphertext = simplified_AES.encrypt(
plaintext) # Running simplified AES.
msg = sendTransformedNonce(ciphertext)
print "Pending message with challenge response:"
print "\t" + str(msg)
print "Sending..."
try:
serverSocket.sendall(msg)
except socket.error:
print ""
print "Error sending data to server"
return 1
print "Challenge response sent."
print ""
else:
handleProtocolError(buff, serverSocket)
return 0
print "Waiting on challenge outcome..."
buff = serverSocket.recv(1024)
if not buff:
handleRemoteHostDisappear(serverSocket)
return 0
else:
print "Response received from server."
print "\t" + "Response: " + str(buff)
print ""
print "Shutting down connection..."
serverSocket.close()
print "Closed this connection's local endpoint."
def main():
"""Driver function for the project"""
serverHost = 'localhost' # The remote host
serverPort = 9000 # The same port as used by the server
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((serverHost, serverPort))
print("Connected to server...");
msg = serverHello()
s.sendall(bytes(msg,'utf-8')) # Sending bytes encoded in utf-8 format.
print("message "+msg+" sent");
data = s.recv(1024).decode('utf-8')
print("Message "+str(data)+" received");
strStatus = "105 Hello"
if data and data.find(strStatus) < 0:
print("Invalid data received. Closing")
else:
# Write appropriate code to parse received string and extract
# the modulus and exponent for public key encryption.
tn="";
te="";
space=False;
for k in data[10:]:
if(k!=" " and not space):#gets n segment
tn+=str(k);
elif(k==" "):
space=True;
elif(space):#gets e segment
te+=str(k);
n = int(tn) # Modulus for public key encryption
e = int(te)# Exponent for public key encryption
print("Server's public key: ("+ str(n)+","+str(e)+")")
symmetricKey = computeSessionKey()
encSymmKey = RSAencrypt(symmetricKey, e, n)
print("Sending symmetric key "+str(symmetricKey)+"...");
msg = sendSessionKey(encSymmKey)
print("Key "+str(msg)+" sent.");
s.sendall(bytes(msg,'utf-8'))
data = s.recv(1024).decode('utf-8')
print("Received "+str(data)+" from server");
strStatus = "113 Nonce"
if data and data.find(strStatus) < 0:
print("Invalid data received. Closing")
else:
# Write code to parse received string and extract encrypted nonce
# from the server. The nonce has been encrypted with the server's
# private key.
encNonce=int(data[10:]);
print("Encrypted nonce: "+ str(encNonce))
nonce = RSAdecrypt(encNonce, e, n)
print("Decrypted nonce: "+ str(nonce))
"""Setting up for Simplified AES encryption"""
plaintext = nonce
simplified_AES.keyExp(symmetricKey) # Generating round keys for AES.
ciphertext = simplified_AES.encrypt(plaintext) # Running simplified AES.
msg = sendTransformedNonce(ciphertext)
s.sendall(bytes(msg,'utf-8'))
print("Message "+ msg+" sent.");
data = s.recv(1024).decode('utf-8')
if data:
print(data)
s.close()
def main():
"""Driver function for the project"""
serverHost = 'localhost' # The remote host
serverPort = 9000 # The same port as used by the server
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((serverHost, serverPort))
msg = serverHello()
s.sendall(bytes(msg,'utf-8')) # Sending bytes encoded in utf-8 format.
data = s.recv(1024).decode('utf-8')
strStatus = "105 Hello"
if data and data.find(strStatus) < 0:
print("Invalid data received. Closing")
else:
# Write appropriate code to parse received string and extract
# the modulus and exponent for public key encryption.
n = int(data.split()[2]) # Modulus for public key encryption
e = int(data.split()[3]) # Exponent for public key encryption
print("Server's public key: ("+ str(n)+","+str(e)+")")
symmetricKey = computeSessionKey()
print ("Symmetric Key:" + str(symmetricKey))
encSymmKey = RSAencrypt(symmetricKey, e, n)
print ("Encrypted Symmetric Key:"+ str(encSymmKey))
msg = sendSessionKey(encSymmKey)
s.sendall(bytes(msg,'utf-8'))
data = s.recv(1024).decode('utf-8')
print (data)
strStatus = "113 Nonce"
if data and data.find(strStatus) < 0:
print("Invalid data received. Closing")
else:
# Write code to parse received string and extract encrypted nonce
# from the server. The nonce has been encrypted with the server's
# private key.
u=data[10:]
print("Encrypted nonce: "+ u)
encNonce=int(u)#converts the parsed Encrypted Nonce to int
nonce = RSAdecrypt(encNonce, e, n)
print("Decrypted nonce: "+ str(nonce))
"""Setting up for Simplified AES encryption"""
plaintext = nonce
simplified_AES.keyExp(symmetricKey) # Generating round keys for AES.
ciphertext = simplified_AES.encrypt(int(plaintext)) # Running simplified AES.
msg = sendTransformedNonce(ciphertext)
s.sendall(bytes(msg,'utf-8'))
data = s.recv(1024).decode('utf-8')
if data:
print(data)
print ("Enter prime numbers. One should be between 907 and 1013, and the other between 53 and 67")
Clientp = int(input('Enter P : '))#request user input for p
Clientq = int(input('Enter Q: '))#request user input for q
while (not isprime(Clientp) or not isprime(Clientq)):#prompt user if value not prime
if not isprime(Clientp):print ("first number was not prime!!!")
if not isprime(Clientq):print ("Second number was not prime!!!")
print("")
Clientp = int(input("Please enter a prime number between 907 and 1013: "))
Clientq = int(input("Please enter a prime number between 53 and 67: "))
while (Clientp<907 or Clientp>1013) or (Clientq<53 or Clientq>67): # prompt user to re-enter prime
if Clientp<907 or Clientp>1013 :print ("first number Must Be greater Than 907 and less than 1013!!!")
if Clientq<53 or Clientq>67:print ("Second number Must Be greater Than 53 and less than 67!!!")
print("")
Clientp = int(input("Please enter a prime number between 907 and 1013: "))
Clientq = int(input("Please enter a prime number between 53 and 67: "))
clientN,clientE=genKeys(Clientp,Clientq)#uses the genKeys function to generate the public key
msg="Client Public Key is :"+ str(clientN)+ " "+str(clientE)
s.sendall(bytes(msg,'utf-8'))#sends client's public key to server
s.close()
ServerDice = list(map(int,ServerDice)) # Converting dice values to ints
strTest = "100 Hello"
if strTest in msg and status == -2:
msg = clientHelloResp(modulus, pub_exp)
s.sendall(bytes(msg,'utf-8'))
status = 1
strSessionKey = "110 SessionKey"
if strSessionKey in msg and status == -2:
RcvdStr = msg.split(' ')
encSymmKey = int(RcvdStr[2])
SymmKey = ## Add code to decrypt symmetric key
state['SymmetricKey'] = SymmKey
# The next line generates the round keys for simplified AES
simplified_AES.keyExp(SymmKey)
challenge = generateNonce()
# Add code to ensure that the challenge can always be encrypted
# correctly with RSA.
state['nonce'] = challenge
msg = SessionKeyResp(RSAcrypt(challenge, priv_exp, modulus))
s.sendall(bytes(msg, 'utf-8'))
status = 1
strSessionKeyResp = "130 "
if strSessionKeyResp in msg and status == -2:
RcvdStr = msg.split(' ')
encryptedChallenge = int(RcvdStr[1])
# The next line runs AES decryption to retrieve the key.
decryptedChallenge = simplified_AES.decrypt(encryptedChallenge)
msg = nonceVerification(challenge, decryptedChallenge)
def processMsgs(s, msg, state):
"""This function processes messages that are read through the socket. It
returns a status, which is an integer indicating whether the operation
was successful"""
status = -2
modulus = int(state['modulus']) # modulus = modulus for RSA
pub_exp = int(state['pub_exp']) # pub_exp = public exponent
priv_exp = int(state['priv_exp']) # priv_exp = secret key
challenge = int(state['nonce']) # challenge = nonce sent to client
SymmKey = int(state['SymmetricKey']) # SymmKey = shared symmetric key
rolls = int(state['Rolls']) # rolls = number of dice rolls
dice = state['Dice'] # Dice = values of dice
dice = list(map(int, dice)) # Converting dice values to ints
strTest = "100 Hello"
if strTest in msg and status == -2:
print("Message received: " + msg)
msg = clientHelloResp(modulus, pub_exp)
s.sendall(bytes(msg, 'utf-8'))
status = 1
print("Message sent: ", msg)
strSessionKey = "110 SessionKey"
if strSessionKey in msg and status == -2:
print("Message received: " + msg)
RcvdStr = msg.split(' ')
encSymmKey = int(RcvdStr[2])
SymmKey = RSAdecrypt(encSymmKey, priv_exp,
modulus) ## Add code to decrypt symmetric key
state['SymmetricKey'] = SymmKey
# The next line generates the round keys for simplified AES
simplified_AES.keyExp(SymmKey)
challenge = generateNonce()
# Add code to ensure that the challenge can always be encrypted
# correctly with RSA.
while (challenge > modulus
): # While loops executes if challenge is more than modulus.
temp = generateNonce() # Generating a new nonce.
challenge = temp # Setting challenge to the newly generated nonce.
#Do this
state['nonce'] = challenge
msg = SessionKeyResp(RSAdecrypt(challenge, priv_exp, modulus))
s.sendall(bytes(msg, 'utf-8'))
status = 1
print("Decrypted Symmetric Key: ", SymmKey)
print("d: ", priv_exp)
print("n: ", modulus)
print("Challenge: ", challenge)
print("Message sent: ", msg)
strSessionKeyResp = "130 Transformed Nonce"
if strSessionKeyResp in msg and status == -2:
print("Message received: " + msg)
RcvdStr = msg[22:]
encryptedChallenge = int(RcvdStr)
# The next line runs AES decryption to retrieve the key.
decryptedChallenge = simplified_AES.decrypt(encryptedChallenge)
msg = nonceVerification(challenge, decryptedChallenge)
s.sendall(bytes(msg, 'utf-8'))
status = 1
strDiceRollResp = "200 Roll Dice"
if strDiceRollResp in msg and status == -2:
print("Message received: " + msg)
RcvdStr = msg[14:]
if (len(RcvdStr) > 0):
RcvdStrParams = RcvdStr.split(',')
toRoll = list(map(int, RcvdStrParams))
rollDice(dice, toRoll)
else:
rollDice(dice)
if (rolls < 3):
status = 1
else:
status = 0
rolls += 1
state['Dice'] = dice
state['Rolls'] = rolls
msg = RollDiceACK(dice)
s.sendall(bytes(msg, 'utf-8'))
# status can only be -2 if none of the other branches were followed
if status == -2:
print("Incoming message was not processed. \r\n Terminating")
status = -1
return status
def handleConnection(p, q, n, e, d, conn, addr):
# Protocol
strHello = "100 Hello"
strHelloResp = "105 Hello"
strSessionKey = "112 SessionKey"
strSessionKeyResp = "113 Nonce"
strNonceResp = "130"
print("Waiting to receive hello message from client...")
buff = conn.recv(1024).decode("utf-8")
if not buff:
handleRemoteHostDisappear(conn)
return
if buff.find(strHello) >= 0:
print("Received hello message.")
msg = clientHelloResp(n, e)
print("Pending response:")
print("\t" + str(msg))
print("Sending...")
try:
conn.sendall(bytes(msg, "utf-8"))
except socket.error:
print("")
print("Error sending data to client")
sys.exit(1)
print("Response sent.")
print("")
else:
handleProtocolError(buff, conn)
return
print("Waiting to receive public key from client...")
buff = conn.recv(1024).decode("utf-8")
if not buff:
handleRemoteHostDisappear(conn)
return
if buff.find(
"110 PB"
) >= 0: # I'll pretend that this will somehow be useful. Hmmm...
print("Public key received.")
print("Parsing response...")
data = buff.split(" ")
n_remote_host = int(data[2]) # Modulus for public key encryption
e_remote_host = int(data[3]) # Exponent for public key encryption
print("Client's public key: (" + str(n_remote_host) + ", " +
str(e_remote_host) + ")")
print("Sending receipt ack...")
try:
conn.sendall(bytes("111 ACK PB", "utf-8"))
except socket.error:
print("")
print("Error sending data to client")
sys.exit(1)
print("Receipt ack sent.")
print("")
else:
handleProtocolError(buff, conn)
return
print("Waiting to retrieve session key from client...")
buff = conn.recv(1024).decode("utf-8")
if not buff:
handleRemoteHostDisappear(conn)
return
if buff.find(strSessionKey) >= 0:
print("Received session key.")
encryptedSymmKey = int(buff.split(" ")[2])
print("Encrypted session key: " + str(encryptedSymmKey))
print("Decrypting session key...")
SymmKey = RSAdecrypt(encryptedSymmKey, d, n)
print("Decrypted session key: " + str(SymmKey))
print("Creating challenge....")
# The next line generates the round keys for simplified AES
simplified_AES.keyExp(SymmKey)
challenge = generateNonce()
while challenge >= n: # Nonce sometimes exceeds n and gives me 400 Error >:(
challenge = generateNonce()
print("Encrypted challenge: " + str(challenge))
print("Decrypting challenge/creating nonce...")
msg = SessionKeyResp(RSAdecrypt(challenge, d, n))
print("Pending message with challenge for client:")
print("\t" + str(msg))
print("Sending...")
try:
conn.sendall(bytes(msg, "utf-8"))
except socket.error:
print("")
print("Error sending data to client")
sys.exit(1)
print("Challenge sent.")
print("")
else:
handleProtocolError(buff, conn)
return
print("Waiting on challenge response from client...")
buff = conn.recv(1024).decode("utf-8")
if not buff:
handleRemoteHostDisappear(conn)
return
if buff.find(strNonceResp) >= 0:
print("Received challenge response.")
encryptedChallenge = int(buff.split(" ")[1])
print("Encrypted challenge response: " + str(encryptedChallenge))
print("Decrypting...")
# The next line runs AES decryption to retrieve the key.
decryptedChallenge = simplified_AES.decrypt(encryptedChallenge)
print("Decrypted challenge response: " + str(decryptedChallenge))
msg = nonceVerification(challenge, decryptedChallenge)
print("Pending message to client:")
print("\t" + str(msg))
print("Sending...")
try:
conn.sendall(bytes(msg, "utf-8"))
except socket.error:
print("")
print("Error sending data to client")
sys.exit(1)
print("Message sent.")
print("")
else:
handleProtocolError(buff, conn)
return
print("Closing connection...")
conn.close()
print("Connection closed.")
print("")
data = conn.recv(1024).decode('utf-8')
if data and data.find(strHello) >= 0:
msg = clientHelloResp(n, e)
conn.sendall(bytes(msg, 'utf-8'))
data = conn.recv(1024).decode('utf-8')
#print("encrypted symm key ",data) //test
if data and data.find(strSessionKey) >= 0:
# Add code to parse the received string and extract the symmetric key //test
splitd = data.split(" ")
encr_symm_key = int(splitd[2])
#print("encrypted symm key ",encr_symm_key) //test
symmKey = RSAdecrypt(encr_symm_key,d,n)# Make appropriate function call to decrypt the symmetric key
#print(symmKey," symm")
# The next line generates the round keys for simplified AES
simplified_AES.keyExp(symmKey)
challenge = generateNonce()
while challenge>n:
challenge = generateNonce()
print("the challenge is ",challenge)
temp = RSAdecrypt(challenge, d, n)
#print ("RSAed nonce",temp) //test
msg = SessionKeyResp(temp)
conn.sendall(bytes(msg,'utf-8'))
data = conn.recv(1024).decode('utf-8')
if data and data.find(strNonceResp) >= 0: # Add code to parse the received string and extract the nonce
splitd = data.split(" ")
encryptedChallenge = int(splitd[1])
#print("plaintext recieved",encryptedChallenge) //test
# The next line runs AES decryption to retrieve the key.
def DHdecrypt(C, symmetricKey, priv, p):
simplified_AES.keyExp(symmetricKey)
plaintext = simplified_AES.decrypt(C)
return plaintext
def encryptMsg(plaintext, symmetricKey, p, gen):
"""Encrypts a message M given parameters above"""
simplified_AES.keyExp(symmetricKey) # Generating round keys for AES.
ciphertext = simplified_AES.encrypt(plaintext) # Running simplified AES.
return ciphertext
def decryptMsg(C, symmetricKey, priv, p):
"""Decrypt a cipher C given parameters above"""
simplified_AES.keyExp(symmetricKey)
plaintext = simplified_AES.decrypt(C)
return plaintext
msg = clientHelloResp(n, e)
conn.sendall(bytes(msg, "utf-8"))
data = conn.recv(1024).decode("utf-8")
print(data)
if data and data.find(strSessionKey) >= 0:
# Add code to parse the received string and extract the symmetric key
a = data[15:]
symmkey = int(a) # converts the parsed symmetric key to a integer
print("D:" + str(d)) # print the value for d
print("N:" + str(n)) # print the value for n
print("E:" + str(e)) # print the value for e
print("PhiN:" + str(phi)) # print the value for phi(N)
SymmKey = RSAdecrypt(symmkey, d, n) # Make appropriate function call to decrypt the symmetric key
print("Decrypted Symmetric Key:" + str(SymmKey))
# The next line generates the round keys for simplified AES
simplified_AES.keyExp(int(SymmKey))
challenge = (
generateNonce()
) # the value returned from calling generateNonce() is assigned to the challenge variable
print("Challenge:" + str(challenge)) # print generated nonce
msg = SessionKeyResp(RSAdecrypt(challenge, d, n))
print("Encrypted Nonce:" + str(msg)) # printing of encrypted nonce
conn.sendall(bytes(msg, "utf-8"))
data = conn.recv(1024).decode("utf-8")
if data and data.find(strNonceResp) >= 0:
# Add code to parse the received string and extract the nonce
encryptedChallenge = int(data[4:])
# The next line runs AES decryption to retrieve the key.
decryptedNonce = simplified_AES.decrypt(encryptedChallenge)
msg = nonceVerification(
challenge, decryptedNonce
def processMsgs(s, msg, state):
"""This function processes messages that are read through the socket. It
returns a status, which is an integer indicating whether the operation
was successful"""
status = -2
rcvr_mod = int(state['modulus']) # Receiver's modulus for RSA
rcvr_exp = int(state['pub_exp']) # Receiver's public exponent
symmetricKey = int(state['SymmetricKey']) # shared symmetric key
rolls = int(state['Rolls']) # Number of dice rolls used
strTest = "101 Hello "
if (strTest in msg and status==-2):
print("Message received: "+ msg)
RcvdStr = msg.split(' ')
rcvr_mod = int(RcvdStr[2]) # Modulus for public key encryption
rcvr_exp = int(RcvdStr[3]) # Exponent for public key encryption
print("Server's public key: ("+ str(rcvr_mod)+","+str(rcvr_exp)+")")
symmetricKey = computeSessionKey()
## Add code to handle the case where the symmetricKey is
## greater than the modulus.
while(symmetricKey > rcvr_mod): # While loop is executed if symmetric key is greater than the modulus.
temp = computeSessionKey() # Generates new session key.
symmetricKey = temp # Set symmetricKey to newly generated session key.
encSymmKey = RSAencrypt(symmetricKey, rcvr_exp, rcvr_mod) ## Add code to encrypt the symmetric key.
msg = sendSessionKey(encSymmKey)
print(msg)
s.sendall(bytes(msg,'utf-8'))
state['modulus'] = rcvr_mod
state['pub_exp'] = rcvr_exp
state['SymmetricKey'] = symmetricKey
status = 1
strNonce = "120 Nonce"
if (strNonce in msg and status==-2):
print("Message received: " + msg)
RcvdStr = msg.split(' ')
encNonce = int(RcvdStr[2])
nonce = RSAdecrypt(encNonce, rcvr_exp, rcvr_mod) ## Add code to decrypt nonce
"""Setting up for Simplified AES encryption"""
plaintext = nonce
simplified_AES.keyExp(symmetricKey) # Generating round keys for AES.
ciphertext = simplified_AES.encrypt(plaintext) # Running simplified AES.
msg = sendTransformedNonce(ciphertext)
s.sendall(bytes(msg,'utf-8'))
status = 1
strDiceRoll = "205 Roll Dice ACK"
if (strDiceRoll in msg and status==-2):
print("Message received: " + msg)
DiceValues = msg[18:].split(',')
if rolls < 2:
WantstoRollMore = input("Do you wish to roll more dice? (y/n): ")
if WantstoRollMore=='y':
msg = RollDice()
s.sendall(bytes(msg,'utf-8'))
rolls += 1
status = 1
else:
status = 0
else:
status = 0
state['Rolls'] = rolls
strSuccess = "250 OK"
strFailure = "400 Error"
if (strFailure in msg and status==-2):
print("Message received: " + str(msg))
status = 0 # To terminate loop at client
if (strSuccess in msg and status==-2):
print("Cryptographic checks completed successfully")
print(msg)
if rolls ==0:
msg = "200 Roll Dice"
else:
msg = RollDice()
s.sendall(bytes(msg,'utf-8'))
rolls += 1
status = 1
if status==-2:
print("Incoming message was not processed. \r\n Terminating")
status = -1
return status
