2 # This module implements a hierarchy of authorities and performs a similar
3 # function as the "tree" module of the original SFA 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.sfalogging import sfa_logger
21 from sfa.util.report import *
22 from sfa.trust.certificate import Keypair
23 from sfa.trust.credential import *
24 from sfa.trust.gid import GID, create_uuid
25 from sfa.util.namespace 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 xrn the human readable name of the authority (urn will be converted to hrn)
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, xrn, gid_filename, privkey_filename, dbinfo_filename):
49 hrn, type = urn_to_hrn(xrn)
51 self.set_gid_filename(gid_filename)
52 self.privkey_filename = privkey_filename
53 self.dbinfo_filename = dbinfo_filename
56 # Set the filename of the GID
58 # @param fn filename of file containing GID
60 def set_gid_filename(self, fn):
61 self.gid_filename = fn
62 self.gid_object = None
64 def get_privkey_filename(self):
65 return self.privkey_filename
67 def get_gid_filename(self):
68 return self.gid_filename
71 # Get the GID in the form of a GID object
73 def get_gid_object(self):
74 if not self.gid_object:
75 self.gid_object = GID(filename = self.gid_filename)
76 return self.gid_object
79 # Get the private key in the form of a Keypair object
81 def get_pkey_object(self):
82 return Keypair(filename = self.privkey_filename)
85 # Get the dbinfo in the form of a dictionary
88 f = file(self.dbinfo_filename)
94 # Replace the GID with a new one. The file specified by gid_filename is
95 # overwritten with the new GID object
97 # @param gid object containing new GID
99 def update_gid_object(self, gid):
100 gid.save_to_file(self.gid_filename)
101 self.gid_object = gid
104 # The Hierarchy class is responsible for managing the tree of authorities.
105 # Each authority is a node in the tree and exists as an AuthInfo object.
107 # The tree is stored on disk in a hierarchical manner than reflects the
108 # structure of the tree. Each authority is a subdirectory, and each subdirectory
109 # contains the GID, pkey, and dbinfo files for that authority (as well as
110 # subdirectories for each sub-authority)
114 # Create the hierarchy object.
116 # @param basedir the base directory to store the hierarchy in
118 def __init__(self, basedir = None):
120 self.config = Config()
121 basedir = os.path.join(self.config.SFA_DATA_DIR, "authorities")
122 self.basedir = basedir
124 # Given a hrn, return the filenames of the GID, private key, and dbinfo
127 # @param xrn the human readable name of the authority (urn will be convertd to hrn)
129 def get_auth_filenames(self, xrn):
130 hrn, type = urn_to_hrn(xrn)
132 parent_hrn = get_authority(hrn)
133 directory = os.path.join(self.basedir, hrn.replace(".", "/"))
135 gid_filename = os.path.join(directory, leaf+".gid")
136 privkey_filename = os.path.join(directory, leaf+".pkey")
137 dbinfo_filename = os.path.join(directory, leaf+".dbinfo")
139 return (directory, gid_filename, privkey_filename, dbinfo_filename)
142 # Check to see if an authority exists. An authority exists if it's disk
145 # @param the human readable name of the authority to check
147 def auth_exists(self, xrn):
148 hrn, type = urn_to_hrn(xrn)
149 (directory, gid_filename, privkey_filename, dbinfo_filename) = \
150 self.get_auth_filenames(hrn)
152 return os.path.exists(gid_filename) and \
153 os.path.exists(privkey_filename) and \
154 os.path.exists(dbinfo_filename)
157 # Create an authority. A private key for the authority and the associated
158 # GID are created and signed by the parent authority.
160 # @param xrn the human readable name of the authority to create (urn will be converted to hrn)
161 # @param create_parents if true, also create the parents if they do not exist
163 def create_auth(self, xrn, create_parents=False):
164 hrn, type = urn_to_hrn(xrn)
165 trace("Hierarchy: creating authority: " + hrn)
167 # create the parent authority if necessary
168 parent_hrn = get_authority(hrn)
169 parent_urn = hrn_to_urn(parent_hrn, 'authority')
170 if (parent_hrn) and (not self.auth_exists(parent_urn)) and (create_parents):
171 self.create_auth(parent_urn, create_parents)
173 (directory, gid_filename, privkey_filename, dbinfo_filename) = \
174 self.get_auth_filenames(hrn)
176 # create the directory to hold the files
178 os.makedirs(directory)
179 # if the path already exists then pass
180 except OSError, (errno, strerr):
184 if os.path.exists(privkey_filename):
185 sfa_logger.debug("using existing key %r for authority %r"%(privkey_filename,hrn))
186 pkey = Keypair(filename = privkey_filename)
188 pkey = Keypair(create = True)
189 pkey.save_to_file(privkey_filename)
191 gid = self.create_gid(xrn, create_uuid(), pkey)
192 gid.save_to_file(gid_filename, save_parents=True)
194 # XXX TODO: think up a better way for the dbinfo to work
196 dbinfo = Config().get_plc_dbinfo()
197 dbinfo_file = file(dbinfo_filename, "w")
198 dbinfo_file.write(str(dbinfo))
202 # Return the AuthInfo object for the specified authority. If the authority
203 # does not exist, then an exception is thrown. As a side effect, disk files
204 # and a subdirectory may be created to store the authority.
206 # @param xrn the human readable name of the authority to create (urn will be converted to hrn).
208 def get_auth_info(self, xrn):
210 #trace("Hierarchy: getting authority: " + hrn)
211 hrn, type = urn_to_hrn(xrn)
212 if not self.auth_exists(hrn):
213 raise MissingAuthority(hrn)
215 (directory, gid_filename, privkey_filename, dbinfo_filename) = \
216 self.get_auth_filenames(hrn)
218 auth_info = AuthInfo(hrn, gid_filename, privkey_filename, dbinfo_filename)
220 # check the GID and see if it needs to be refreshed
221 gid = auth_info.get_gid_object()
222 gid_refreshed = self.refresh_gid(gid)
223 if gid != gid_refreshed:
224 auth_info.update_gid_object(gid_refreshed)
229 # Create a new GID. The GID will be signed by the authority that is it's
230 # immediate parent in the hierarchy (and recursively, the parents' GID
231 # will be signed by its parent)
233 # @param hrn the human readable name to store in the GID
234 # @param uuid the unique identifier to store in the GID
235 # @param pkey the public key to store in the GID
237 def create_gid(self, xrn, uuid, pkey):
238 hrn, type = urn_to_hrn(xrn)
239 # Using hrn_to_urn() here to make sure the urn is in the right format
240 # If xrn was a hrn instead of a urn, then the gid's urn will be
242 urn = hrn_to_urn(hrn, type)
243 gid = GID(subject=hrn, uuid=uuid, hrn=hrn, urn=urn)
245 parent_hrn = get_authority(hrn)
246 if not parent_hrn or hrn == self.config.SFA_INTERFACE_HRN:
247 # if there is no parent hrn, then it must be self-signed. this
248 # is where we terminate the recursion
249 gid.set_issuer(pkey, hrn)
251 # we need the parent's private key in order to sign this GID
252 parent_auth_info = self.get_auth_info(parent_hrn)
253 gid.set_issuer(parent_auth_info.get_pkey_object(), parent_auth_info.hrn)
254 gid.set_parent(parent_auth_info.get_gid_object())
255 gid.set_intermediate_ca(True)
264 # Refresh a GID. The primary use of this function is to refresh the
265 # the expiration time of the GID. It may also be used to change the HRN,
266 # UUID, or Public key of the GID.
268 # @param gid the GID to refresh
269 # @param hrn if !=None, change the hrn
270 # @param uuid if !=None, change the uuid
271 # @param pubkey if !=None, change the public key
273 def refresh_gid(self, gid, xrn=None, uuid=None, pubkey=None):
274 # TODO: compute expiration time of GID, refresh it if necessary
275 gid_is_expired = False
277 # update the gid if we need to
278 if gid_is_expired or xrn or uuid or pubkey:
283 uuid = gid.get_uuid()
285 pubkey = gid.get_pubkey()
287 gid = self.create_gid(xrn, uuid, pubkey)
292 # Retrieve an authority credential for an authority. The authority
293 # credential will contain the authority privilege and will be signed by
294 # the authority's parent.
296 # @param hrn the human readable name of the authority (urn is converted to hrn)
297 # @param authority type of credential to return (authority | sa | ma)
299 def get_auth_cred(self, xrn, kind="authority"):
300 hrn, type = urn_to_hrn(xrn)
301 auth_info = self.get_auth_info(hrn)
302 gid = auth_info.get_gid_object()
304 cred = Credential(subject=hrn)
305 cred.set_gid_caller(gid)
306 cred.set_gid_object(gid)
307 cred.set_privileges(kind)
308 cred.get_privileges().delegate_all_privileges(True)
309 #cred.set_pubkey(auth_info.get_gid_object().get_pubkey())
311 parent_hrn = get_authority(hrn)
312 if not parent_hrn or hrn == self.config.SFA_INTERFACE_HRN:
313 # if there is no parent hrn, then it must be self-signed. this
314 # is where we terminate the recursion
315 cred.set_issuer_keys(auth_info.get_privkey_filename(), auth_info.get_gid_filename())
317 # we need the parent's private key in order to sign this GID
318 parent_auth_info = self.get_auth_info(parent_hrn)
319 cred.set_issuer_keys(parent_auth_info.get_privkey_filename(), parent_auth_info.get_gid_filename())
322 cred.set_parent(self.get_auth_cred(parent_hrn, kind))
329 # Retrieve an authority ticket. An authority ticket is not actually a
330 # redeemable ticket, but only serves the purpose of being included as the
331 # parent of another ticket, in order to provide a chain of authentication
334 # This looks almost the same as get_auth_cred, but works for tickets
335 # XXX does similarity imply there should be more code re-use?
337 # @param xrn the human readable name of the authority (urn is converted to hrn)
339 def get_auth_ticket(self, xrn):
340 hrn, type = urn_to_hrn(xrn)
341 auth_info = self.get_auth_info(hrn)
342 gid = auth_info.get_gid_object()
344 ticket = SfaTicket(subject=hrn)
345 ticket.set_gid_caller(gid)
346 ticket.set_gid_object(gid)
347 ticket.set_delegate(True)
348 ticket.set_pubkey(auth_info.get_gid_object().get_pubkey())
350 parent_hrn = get_authority(hrn)
352 # if there is no parent hrn, then it must be self-signed. this
353 # is where we terminate the recursion
354 ticket.set_issuer(auth_info.get_pkey_object(), hrn)
356 # we need the parent's private key in order to sign this GID
357 parent_auth_info = self.get_auth_info(parent_hrn)
358 ticket.set_issuer(parent_auth_info.get_pkey_object(), parent_auth_info.hrn)
359 ticket.set_parent(self.get_auth_cred(parent_hrn))