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-rw-r--r--laas-fog/source/api/vpn.py235
1 files changed, 235 insertions, 0 deletions
diff --git a/laas-fog/source/api/vpn.py b/laas-fog/source/api/vpn.py
new file mode 100644
index 0000000..336a681
--- /dev/null
+++ b/laas-fog/source/api/vpn.py
@@ -0,0 +1,235 @@
+from abc import ABCMeta, abstractmethod
+import ldap
+import os
+import random
+from base64 import b64encode
+from database import BookingDataBase
+
+
+class VPN_BaseClass:
+ """
+ the vpn handler abstract class / interface
+
+ """
+ __metaclass__ = ABCMeta
+
+ @abstractmethod
+ def __init__(self, config):
+ """
+ config is the parsed vpn.yaml file
+ """
+ pass
+
+ @abstractmethod
+ def makeNewUser(self, user=None):
+ """
+ This method is called when a vpn user is needed.
+ This method should create a vpn user in whatever
+ runs the vpn in our infrastructure. returns the
+ credentials for the vpn user and some uid
+ that will be associated with the booking in the
+ database. This uid is used to track the vpn user and
+ to delete the user when there are no bookings associated
+ with that uid.
+ """
+ user = "username"
+ passwd = "password"
+ uid = "some way for you to identify this user in the database"
+ return user, passwd, uid
+
+ @abstractmethod
+ def removeOldUsers(self):
+ """
+ checks the list of all vpn users against a list of
+ vpn users associated with active bookings and removes
+ users who dont have an active booking
+
+ If you want your vpn accounts to be persistent,
+ you can just ignore this
+ """
+ pass
+
+
+names = [
+ 'frodo baggins', 'samwise gamgee', 'peregrin took', 'meriadoc brandybuck',
+ 'bilbo baggins', 'gandalf grey', 'aragorn dunadan', 'arwen evenstar',
+ 'saruman white', 'pippin took', 'merry brandybuck', 'legolas greenleaf',
+ 'gimli gloin', 'anakin skywalker', 'padme amidala', 'han solo',
+ 'jabba hut', 'mace windu', 'sount dooku', 'qui-gon jinn',
+ 'admiral ackbar', 'emperor palpatine'
+]
+
+
+class VPN:
+ """
+ This class communicates with the ldap server to manage vpn users.
+ This class extends the above ABC, and implements the makeNewUser,
+ removeOldUser, and __init__ abstract functions you must override to
+ extend the VPN_BaseClass
+ """
+
+ def __init__(self, config):
+ """
+ init takes the parsed vpn config file as an arguement.
+ automatically connects and authenticates on the ldap server
+ based on the configuration file
+ """
+ self.config = config
+ server = config['server']
+ self.uri = "ldap://"+server
+
+ self.conn = None
+ user = config['authentication']['user']
+ pswd = config['authentication']['pass']
+ if os.path.isfile(pswd):
+ pswd = open(pswd).read()
+ self.connect(user, pswd)
+
+ def connect(self, root_dn, root_pass):
+ """
+ Opens a connection to the server in the config file
+ and authenticates as the given user
+ """
+ self.conn = ldap.initialize(self.uri)
+ self.conn.simple_bind_s(root_dn, root_pass)
+
+ def addUser(self, full_name, passwd):
+ """
+ Adds a user to the ldap server. Creates the new user with the classes
+ and in the directory given in the config file.
+ full_name should be two tokens seperated by a space. The first token
+ will become the username
+ private helper function for the makeNewUser()
+ """
+ first = full_name.split(' ')[0]
+ last = full_name.split(' ')[1]
+ user_dir = self.config['directory']['user']
+ user_dir += ','+self.config['directory']['root']
+ dn = "uid=" + first + ',' + user_dir
+ record = [
+ ('objectclass', ['top', 'inetOrgPerson']),
+ ('uid', first),
+ ('cn', full_name),
+ ('sn', last),
+ ('userpassword', passwd),
+ ('ou', self.config['directory']['user'].split('=')[1])
+ ]
+ self.conn.add_s(dn, record)
+ return dn
+
+ def makeNewUser(self, name=None):
+ """
+ creates a new user in the ldap database, with the given name
+ if supplied. If no name is given, we will try to select from the
+ pre-written list above, and will resort to generating a random string
+ as a username if the preconfigured names are all taken.
+ Returns the username and password the user needs to authenticate, and
+ the dn that we can use to manage the user.
+ """
+ if name is None:
+ i = 0
+ while not self.checkName(name):
+ i += 1
+ if i == 20:
+ name = self.randoString(8)
+ name += ' '+self.randoString(8)
+ break # generates a random name to prevent infinite loop
+ name = self.genUserName()
+ passwd = self.randoString(15)
+ dn = self.addUser(name, passwd)
+ return name, passwd, dn
+
+ def checkName(self, name):
+ """
+ returns true if the name is available
+ """
+ if name is None:
+ return False
+ uid = name.split(' ')[0]
+ base = self.config['directory']['user'] + ','
+ base += self.config['directory']['root']
+ filtr = '(uid=' + uid + ')'
+ timeout = 5
+ ans = self.conn.search_st(
+ base,
+ ldap.SCOPE_SUBTREE,
+ filtr,
+ timeout=timeout
+ )
+ return len(ans) < 1
+
+ @staticmethod
+ def randoString(n):
+ """
+ uses /dev/urandom to generate a random string of length n
+ """
+ n = int(n)
+ # defines valid characters
+ alpha = 'abcdefghijklmnopqrstuvwxyz'
+ alpha_num = alpha
+ alpha_num += alpha.upper()
+ alpha_num += "0123456789"
+
+ # generates random string from /dev/urandom
+ rnd = b64encode(os.urandom(3*n)).decode('utf-8')
+ random_string = ''
+ for char in rnd:
+ if char in alpha_num:
+ random_string += char
+ return str(random_string[:n])
+
+ def genUserName(self):
+ """
+ grabs a random name from the list above
+ """
+ i = random.randint(0, len(names) - 1)
+ return names[i]
+
+ def deleteUser(self, dn):
+ self.conn.delete(dn)
+
+ def getAllUsers(self):
+ """
+ returns all the user dn's in the ldap database in a list
+ """
+ base = self.config['directory']['user'] + ','
+ base += self.config['directory']['root']
+ filtr = '(objectclass='+self.config['user']['objects'][-1]+')'
+ timeout = 10
+ ans = self.conn.search_st(
+ base,
+ ldap.SCOPE_SUBTREE,
+ filtr,
+ timeout=timeout
+ )
+ users = []
+ for user in ans:
+ users.append(user[0]) # adds the dn of each user
+ return users
+
+ def removeOldUsers(self):
+ """
+ removes users from the ldap server who dont have any active bookings.
+ will not delete a user if their uid's are named in the config
+ file as permanent users.
+ """
+ db = self.config['database']
+ # the dn of all users who have an active booking
+ active_users = BookingDataBase(db).getVPN()
+ all_users = self.getAllUsers()
+ for user in all_users:
+ # checks if they are a permanent user
+ if self.is_permanent_user(user):
+ continue
+ # deletes the user if they dont have an active booking
+ if user not in active_users:
+ self.deleteUser(user)
+
+ def is_permanent_user(self, dn):
+ for user in self.config['permanent_users']:
+ if (user in dn) or (dn in user):
+ return True
+ return False
+
+
+VPN_BaseClass.register(VPN)