util/hierarchy.py

   1 # hierarchy.py
   2 #
   3 # hierarchy of GENI authorities
   4 #
   5 # This correspond's almost identically to the functionality of Soner's
   6 # "tree" module. Each component of an HRN is stored in a different subdirectory.
   7 # Inside this subdirectory are:
   8 #      *.GID - GID file
   9 #      *.PKEY - private key file
  10 #      *.DBINFO - database info
  11
  12 import os
  13 from cert import *
  14 from gid import *
  15 from misc import *
  16 from config import *
  17
  18 class AuthInfo():
  19     hrn = None
  20     gid_filename = None
  21     privkey_filename = None
  22     dbinfo_filename = None
  23
  24     def __init__(self, hrn, gid_filename, privkey_filename, dbinfo_filename):
  25         self.hrn = hrn
  26         self.gid_filename = gid_filename
  27         self.privkey_filename = privkey_filename
  28         self.dbinfo_filename = dbinfo_filename
  29
  30     def get_gid_object(self):
  31         return GID(filename = self.gid_filename)
  32
  33     def get_pkey_object(self):
  34         return Keypair(filename = self.privkey_filename)
  35
  36     def get_dbinfo(self):
  37         f = file(self.dbinfo_filename)
  38         dict = eval(f.read())\r
  39         f.close()\r
  40         return dict\r
  41
  42 class Hierarchy():
  43     def __init__(self, basedir="."):
  44         self.basedir = basedir
  45
  46     def get_auth_filenames(self, hrn):
  47         leaf = get_leaf(hrn)
  48         parent_hrn = get_authority(hrn)
  49         directory = os.path.join(self.basedir, hrn.replace(".", "/"))
  50
  51         gid_filename = os.path.join(directory, leaf+".gid")
  52         privkey_filename = os.path.join(directory, leaf+".pkey")
  53         dbinfo_filename = os.path.join(directory, leaf+".dbinfo")
  54
  55         return (directory, gid_filename, privkey_filename, dbinfo_filename)
  56
  57     def auth_exists(self, hrn):
  58         (directory, gid_filename, privkey_filename, dbinfo_filename) = \
  59             self.get_auth_filenames(hrn)
  60
  61         return os.path.exists(gid_filename) and \
  62                os.path.exists(privkey_filename) and \
  63                os.path.exists(dbinfo_filename)
  64
  65     def create_auth(self, hrn):
  66         (directory, gid_filename, privkey_filename, dbinfo_filename) = \
  67             self.get_auth_filenames(hrn)
  68
  69         # create the directory to hold the files
  70         try:
  71             os.makedirs(directory)\r
  72         # if the path already exists then pass\r
  73         except OSError, (errno, strerr):\r
  74             if errno == 17:\r
  75                 pass
  76
  77         pkey = Keypair(create = True)
  78         pkey.save_to_file(privkey_filename)
  79
  80         gid = self.create_gid(hrn, create_uuid(), pkey)
  81         gid.save_to_file(gid_filename)
  82
  83         # XXX TODO: think up a better way for the dbinfo to work
  84
  85         dbinfo = get_default_dbinfo()
  86         dbinfo_file = file(dbinfo_filename, "w")
  87         dbinfo_file.write(str(dbinfo))\r
  88         dbinfo_file.close()
  89
  90     def get_auth_info(self, hrn, can_create=True):
  91         if not self.auth_exists(hrn):
  92             if not can_create:
  93                 return MissingAuthority(hrn)
  94
  95             self.create_auth(hrn)
  96
  97         (directory, gid_filename, privkey_filename, dbinfo_filename) = \
  98             self.get_auth_filenames(hrn)
  99
 100         auth_info = AuthInfo(hrn, gid_filename, privkey_filename, dbinfo_filename)
 101
 102         return auth_info
 103
 104     def create_gid(self, hrn, uuid, pkey):
 105         parent_hrn = get_authority(hrn)
 106
 107         gid = GID(subject=hrn, uuid=uuid)
 108
 109         if not parent_hrn:
 110             # if there is no parent hrn, then it must be self-signed. this
 111             # is where we terminate the recursion
 112             gid.set_issuer(pkey, hrn)
 113         else:
 114             # we need the parent's private key in order to sign this GID
 115             parent_auth_info = self.get_auth_info(parent_hrn)
 116             gid.set_issuer(parent_auth_info.get_pkey_object(), parent_auth_info.hrn)
 117             gid.set_parent(parent_auth_info.get_gid_object())
 118
 119         gid.set_pubkey(pkey)
 120         gid.sign()
 121
 122         return gid
 123
 124     def refresh_gid(self, gid, hrn=None, uuid=None, pubkey=None):
 125         # TODO: compute expiration time of GID, refresh it if necessary
 126         gid_is_expired = False
 127
 128         # update the gid if we need to
 129         if gid_is_expired or hrn or uuid or pubkey:
 130             if not hrn:
 131                 hrn = gid.get_hrn()
 132             if not uuid:
 133                 uuid = gid.get_uuid()
 134             if not pubkey:
 135                 pubkey = gid.get_pubkey()
 136
 137             gid = self.create_gid(hrn, uuid, pubkey)
 138
 139         return gid
 140