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# -*- coding: utf-8 -*-
import StringIO
import hashlib
import sys
import os
import os.path
import fileinput
import logging
logger = logging.getLogger(__name__)
from permission import *
from config import config
class ObjectError(Exception):
pass;
class Object:
def __init__(self, name, owner, split_name = True):
self.hash = name
self.owner = owner
if split_name:
self.object_path = os.path.join(config.root, owner, name[:2], name[2:])
else:
self.object_path = os.path.join(config.root, owner, name)
def exists(self):
return os.path.exists(self.object_path)
class ObjectReader(Object):
def __init__(self, hash, owner, split_name = True):
Object.__init__(self, hash, owner, split_name)
if not self.exists():
logger.error("Object {} can't be found for user {}".format(self.hash,
self.owner))
raise ObjectError
def get_permission(self, user):
with open(os.path.join(self.object_path, 'permissions'), 'r') as file:
for line in file:
name, perm, key = line.split()
if name == user:
return int(perm)
return None
def get_key(self, user):
with open(os.path.join(self.object_path, 'permissions'), 'r') as file:
for line in file:
name, perm, key = line.split()
if name == user:
return key
return None
def get_permission_key(self, user):
with open(os.path.join(self.object_path, 'permissions'), 'r') as file:
for line in file:
name, perm, key = line.split()
if name == user:
return (int(perm), key)
return (None, None)
def get_child_list(self, user):
perm = self.get_permission(user)
if not perm & LIST:
logger.error("User {} doesn't have the list permission for object {}"
.format(user, self.hash))
raise PermissionError
file = open(os.path.join(self.object_path, 'childs'), 'r')
result = []
for line in file:
name = line.rstrip('\n')
try:
child = ObjectReader(name, self.owner)
except ObjectError:
logger.error('Object {} doesn\'t exist'.format(name))
else:
perm, key = child.get_permission_key(user)
if perm > 0:
result.append((name, perm, key))
file.close()
return result
def get_content(self, user):
"""Return object content and the user key to decrypt it."""
perm, key = self.get_permission_key(user)
if not perm & READ :
logger.error("User {} doesn't have read access to object {}"
.format(user, self.hash))
raise PermissionError
with open(os.path.join(self.object_path, 'object'), 'r') as file:
content = file.read()
return content, key
class ObjectWriter(ObjectReader):
def __init__(self, hash, owner, split_name = True, key = None):
Object.__init__(self, hash, owner, split_name)
self.files = ('permissions', 'children', 'object')
self.__create_skeleton(key)
def __create_skeleton(self, key):
#new object
if not self.exists():
os.makedirs(self.object_path)
for filename in self.files:
file = open(os.path.join(self.object_path, filename), "w")
file.close()
#give all the permissions to the owner
ALLPERM = READ + MODIFY + APPEND + LIST
self.add_user(self.owner, ALLPERM, key)
def write(self, user, content):
perm = self.get_permission(user)
if not perm & MODIFY:
logger.error("User {} doesn't have the modify permission for object {}"
.format(user, self.hash))
raise PermissionError
with open(os.path.join(self.object_path, 'object'), "w") as file:
file.write('{}'.format(content))
def append(self, user, content, parent):
parent_object = ObjectReader(parent, self.owner)
perm = parent_object.get_permission(user)
if not perm & APPEND:
logger.error("User {} doesn't have the modify permission for object {}"
.format(user, parent))
raise PermissionError
with open(os.path.join(self.object_path, 'object'), "w") as file:
for k, v in content:
file.write('{} {}\n'.format(k,v))
#add the child hash to the parent
with open(os.path.join(parent_object.object_path, 'children'), "a") as file:
file.write('{} {}\n'.format(self.hash))
def add_user(self, user, perm, key = None):
with open(os.path.join(self.object_path, 'permissions'), "a") as file:
if key:
file.write('{} {} {}\n'.format(user, perm, key))
else:
file.write('{} {} None\n'.format(user, perm, key))
if __name__ == '__main__':
jid = 'thrasibule@alias.im'
hash = hashlib.sha1(jid).hexdigest()
config.root = '/var/lib/alias'
print ObjectReader(hash, jid).get_content(jid)
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