def Registration(self, request, context):
"""
Request - pid : nonce : key - encrypted message
Decrypt, then make list, make a response : nonce -1
Encrypt response and send it
"""
items = self.Decrypt(request.name.encode())
# print(items)
if "FS" in items[0]:
self.fs_keys[items[0]] = items[2].encode()
r = str(int(items[1]) - 1)
print(
"Received a request for Registration by FS with Port {}.\nSent a Response to the FS: `{}`\n"
.format(items[0][2:], r))
res = self.Encrypt(r, 0, items[0])
else:
self.client_keys[items[0]] = items[2].encode()
self.client_notification[items[0]] = []
r = str(int(items[1]) - 1)
print(
"Received a request for Registration by client with PID {}.\nSent a response to the client: `{}`\n"
.format(items[0], r))
res = self.Encrypt(r, 1, items[0])
return centralpb.Response2(name=res.decode())
def GiveFS(self, request, context):
pid = request.name
print("Received a request for FS list by client with PID {}.".format(
pid))
fs = centralpb.Response2()
# print(self.fs_keys.keys(), type(self.fs_keys.keys()))
plaintext = " ".join(list(self.fs_keys.keys()))
ciphertext = self.Encrypt(plaintext, 1, pid).decode()
fs.name = ciphertext
return fs
def NewFile(self, request, context):
fileserver, filename = request.name.split()
fernet = Fernet(self.fs_keys[fileserver])
filename, pid = fernet.decrypt(filename.encode()).decode().split()
print(
"New File {} has been created in FileServer {} by client with pid {}."
.format(filename, fileserver, pid))
for k in self.client_notification.keys():
if pid != k:
self.client_notification[k].append((filename, fileserver))
return centralpb.Response2(name="")
def GetUpdate(self, request, context):
pid = request.name
fernet = Fernet(self.client_keys[pid])
plaintext = ""
for u in self.client_notification[pid]:
plaintext += "{}[{}] ".format(u[0], u[1])
if len(plaintext) > 0:
plaintext = plaintext[:-1]
print("Sent a Notification to {} about new files created.".format(
request.name))
self.client_notification[pid] = []
ciphertext = fernet.encrypt(plaintext.encode()).decode()
return centralpb.Response2(name=ciphertext)
def GenKey(self, request, context):
"""
pid, nonce, FS
response encrypted by kdc_key : nonce, FS, shared_key, ticket((shared_key + pid) encrypted by FS_KDC)
"""
items = request.name.split()
pid, fs, nonce = items
kdc_client_key = self.client_keys[pid]
kdc_fs_key = self.fs_keys[fs]
shared_key = Fernet.generate_key().decode()
ticket = shared_key + " " + pid
ticketCipher = self.Encrypt(ticket, 0, fs).decode()
plaintext = nonce + " " + fs + " " + shared_key + " " + ticketCipher
ciphertext = self.Encrypt(plaintext, 1, pid).decode()
print(
"\nReceived a Session Establishment Request from client with pid {} for FileServer {}.\nSent a Ticket and generated a Session-Key for the same.\n"
.format(pid, fs))
return centralpb.Response2(name=ciphertext)