2 # This module implements a hierarchy of authorities and performs a similar
3 # function as the "tree" module of the original geniwrapper prototype. An HRN
4 # is assumed to be a string of authorities separated by dots. For example,
5 # "planetlab.us.arizona.bakers". Each component of the HRN is a different
6 # authority, with the last component being a leaf in the tree.
8 # Each authority is stored in a subdirectory on the registry. Inside this
9 # subdirectory are several files:
11 # *.PKEY - private key file
12 # *.DBINFO - database info
20 from sfa.util.report import *
21 from sfa.trust.certificate import Keypair
22 from sfa.trust.credential import *
23 from sfa.trust.gid import GID, create_uuid
25 from sfa.util.misc import *
26 from sfa.util.config import Config
27 from sfa.util.sfaticket import SfaTicket
30 # The AuthInfo class contains the information for an authority. This information
31 # includes the GID, private key, and database connection information.
37 privkey_filename = None
38 dbinfo_filename = None
41 # Initialize and authority object.
43 # @param hrn the human readable name of the authority
44 # @param gid_filename the filename containing the GID
45 # @param privkey_filename the filename containing the private key
46 # @param dbinfo_filename the filename containing the database info
48 def __init__(self, hrn, gid_filename, privkey_filename, dbinfo_filename):
50 self.set_gid_filename(gid_filename)
51 self.privkey_filename = privkey_filename
52 self.dbinfo_filename = dbinfo_filename
55 # Set the filename of the GID
57 # @param fn filename of file containing GID
59 def set_gid_filename(self, fn):
60 self.gid_filename = fn
61 self.gid_object = None
64 # Get the GID in the form of a GID object
66 def get_gid_object(self):
67 if not self.gid_object:
68 self.gid_object = GID(filename = self.gid_filename)
69 return self.gid_object
72 # Get the private key in the form of a Keypair object
74 def get_pkey_object(self):
75 return Keypair(filename = self.privkey_filename)
78 # Get the dbinfo in the form of a dictionary
81 f = file(self.dbinfo_filename)
87 # Replace the GID with a new one. The file specified by gid_filename is
88 # overwritten with the new GID object
90 # @param gid object containing new GID
92 def update_gid_object(self, gid):
93 gid.save_to_file(self.gid_filename)
97 # The Hierarchy class is responsible for managing the tree of authorities.
98 # Each authority is a node in the tree and exists as an AuthInfo object.
100 # The tree is stored on disk in a hierarchical manner than reflects the
101 # structure of the tree. Each authority is a subdirectory, and each subdirectory
102 # contains the GID, pkey, and dbinfo files for that authority (as well as
103 # subdirectories for each sub-authority)
107 # Create the hierarchy object.
109 # @param basedir the base directory to store the hierarchy in
111 def __init__(self, basedir = None):
113 self.config = Config()
114 basedir = os.path.join(self.config.SFA_BASE_DIR, "authorities")
115 self.basedir = basedir
117 # Given a hrn, return the filenames of the GID, private key, and dbinfo
120 # @param hrn the human readable name of the authority
122 def get_auth_filenames(self, hrn):
124 parent_hrn = get_authority(hrn)
125 directory = os.path.join(self.basedir, hrn.replace(".", "/"))
127 gid_filename = os.path.join(directory, leaf+".gid")
128 privkey_filename = os.path.join(directory, leaf+".pkey")
129 dbinfo_filename = os.path.join(directory, leaf+".dbinfo")
131 return (directory, gid_filename, privkey_filename, dbinfo_filename)
134 # Check to see if an authority exists. An authority exists if it's disk
137 # @param the human readable name of the authority to check
139 def auth_exists(self, hrn):
140 (directory, gid_filename, privkey_filename, dbinfo_filename) = \
141 self.get_auth_filenames(hrn)
143 return os.path.exists(gid_filename) and \
144 os.path.exists(privkey_filename) and \
145 os.path.exists(dbinfo_filename)
148 # Create an authority. A private key for the authority and the associated
149 # GID are created and signed by the parent authority.
151 # @param hrn the human readable name of the authority to create
152 # @param create_parents if true, also create the parents if they do not exist
154 def create_auth(self, hrn, create_parents=False):
155 trace("Hierarchy: creating authority: " + hrn)
157 # create the parent authority if necessary
158 parent_hrn = get_authority(hrn)
159 if (parent_hrn) and (not self.auth_exists(parent_hrn)) and (create_parents):
160 self.create_auth(parent_hrn, create_parents)
162 (directory, gid_filename, privkey_filename, dbinfo_filename) = \
163 self.get_auth_filenames(hrn)
165 # create the directory to hold the files
167 os.makedirs(directory)
168 # if the path already exists then pass
169 except OSError, (errno, strerr):
173 if os.path.exists(privkey_filename):
174 print "using existing key", privkey_filename, "for authority", hrn
175 pkey = Keypair(filename = privkey_filename)
177 pkey = Keypair(create = True)
178 pkey.save_to_file(privkey_filename)
180 gid = self.create_gid(hrn, create_uuid(), pkey)
181 gid.save_to_file(gid_filename, save_parents=True)
183 # XXX TODO: think up a better way for the dbinfo to work
185 dbinfo = Config().get_plc_dbinfo()
186 dbinfo_file = file(dbinfo_filename, "w")
187 dbinfo_file.write(str(dbinfo))
191 # Return the AuthInfo object for the specified authority. If the authority
192 # does not exist, then an exception is thrown. As a side effect, disk files
193 # and a subdirectory may be created to store the authority.
195 # @param hrn the human readable name of the authority to create.
197 def get_auth_info(self, hrn):
198 #trace("Hierarchy: getting authority: " + hrn)
200 if not self.auth_exists(hrn):
201 raise MissingAuthority(hrn)
203 (directory, gid_filename, privkey_filename, dbinfo_filename) = \
204 self.get_auth_filenames(hrn)
206 auth_info = AuthInfo(hrn, gid_filename, privkey_filename, dbinfo_filename)
208 # check the GID and see if it needs to be refreshed
209 gid = auth_info.get_gid_object()
210 gid_refreshed = self.refresh_gid(gid)
211 if gid != gid_refreshed:
212 auth_info.update_gid_object(gid_refreshed)
217 # Create a new GID. The GID will be signed by the authority that is it's
218 # immediate parent in the hierarchy (and recursively, the parents' GID
219 # will be signed by its parent)
221 # @param hrn the human readable name to store in the GID
222 # @param uuid the unique identifier to store in the GID
223 # @param pkey the public key to store in the GID
225 def create_gid(self, hrn, uuid, pkey):
226 gid = GID(subject=hrn, uuid=uuid, hrn=hrn)
228 parent_hrn = get_authority(hrn)
229 if not parent_hrn or hrn == self.config.SFA_INTERFACE_HRN:
230 # if there is no parent hrn, then it must be self-signed. this
231 # is where we terminate the recursion
232 gid.set_issuer(pkey, hrn)
234 # we need the parent's private key in order to sign this GID
235 parent_auth_info = self.get_auth_info(parent_hrn)
236 gid.set_issuer(parent_auth_info.get_pkey_object(), parent_auth_info.hrn)
237 gid.set_parent(parent_auth_info.get_gid_object())
246 # Refresh a GID. The primary use of this function is to refresh the
247 # the expiration time of the GID. It may also be used to change the HRN,
248 # UUID, or Public key of the GID.
250 # @param gid the GID to refresh
251 # @param hrn if !=None, change the hrn
252 # @param uuid if !=None, change the uuid
253 # @param pubkey if !=None, change the public key
255 def refresh_gid(self, gid, hrn=None, uuid=None, pubkey=None):
256 # TODO: compute expiration time of GID, refresh it if necessary
257 gid_is_expired = False
259 # update the gid if we need to
260 if gid_is_expired or hrn or uuid or pubkey:
264 uuid = gid.get_uuid()
266 pubkey = gid.get_pubkey()
268 gid = self.create_gid(hrn, uuid, pubkey)
273 # Retrieve an authority credential for an authority. The authority
274 # credential will contain the authority privilege and will be signed by
275 # the authority's parent.
277 # @param hrn the human readable name of the authority
278 # @param authority type of credential to return (authority | sa | ma)
280 def get_auth_cred(self, hrn, kind="authority"):
281 auth_info = self.get_auth_info(hrn)
282 gid = auth_info.get_gid_object()
284 cred = Credential(subject=hrn)
285 cred.set_gid_caller(gid)
286 cred.set_gid_object(gid)
287 cred.set_privileges(kind)
288 cred.set_delegate(True)
289 cred.set_pubkey(auth_info.get_gid_object().get_pubkey())
291 parent_hrn = get_authority(hrn)
292 if not parent_hrn or hrn == self.config.SFA_INTERFACE_HRN:
293 # if there is no parent hrn, then it must be self-signed. this
294 # is where we terminate the recursion
295 cred.set_issuer(auth_info.get_pkey_object(), hrn)
297 # we need the parent's private key in order to sign this GID
298 parent_auth_info = self.get_auth_info(parent_hrn)
299 cred.set_issuer(parent_auth_info.get_pkey_object(), parent_auth_info.hrn)
300 cred.set_parent(self.get_auth_cred(parent_hrn, kind))
307 # Retrieve an authority ticket. An authority ticket is not actually a
308 # redeemable ticket, but only serves the purpose of being included as the
309 # parent of another ticket, in order to provide a chain of authentication
312 # This looks almost the same as get_auth_cred, but works for tickets
313 # XXX does similarity imply there should be more code re-use?
315 # @param hrn the human readable name of the authority
317 def get_auth_ticket(self, hrn):
318 auth_info = self.get_auth_info(hrn)
319 gid = auth_info.get_gid_object()
321 ticket = SfaTicket(subject=hrn)
322 ticket.set_gid_caller(gid)
323 ticket.set_gid_object(gid)
324 ticket.set_delegate(True)
325 ticket.set_pubkey(auth_info.get_gid_object().get_pubkey())
327 parent_hrn = get_authority(hrn)
329 # if there is no parent hrn, then it must be self-signed. this
330 # is where we terminate the recursion
331 ticket.set_issuer(auth_info.get_pkey_object(), hrn)
333 # we need the parent's private key in order to sign this GID
334 parent_auth_info = self.get_auth_info(parent_hrn)
335 ticket.set_issuer(parent_auth_info.get_pkey_object(), parent_auth_info.hrn)
336 ticket.set_parent(self.get_auth_cred(parent_hrn))