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
16 from sfa.util.faults import MissingAuthority
17 from sfa.util.sfalogging import logger
18 from sfa.util.xrn import get_leaf, get_authority, hrn_to_urn, urn_to_hrn
19 from sfa.trust.certificate import Keypair
20 from sfa.trust.credential import Credential
21 from sfa.trust.gid import GID, create_uuid
22 from sfa.util.config import Config
23 from sfa.trust.sfaticket import SfaTicket
26 # The AuthInfo class contains the information for an authority. This information
27 # includes the GID, private key, and database connection information.
33 privkey_filename = None
35 # Initialize and authority object.
37 # @param xrn the human readable name of the authority (urn will be converted to hrn)
38 # @param gid_filename the filename containing the GID
39 # @param privkey_filename the filename containing the private key
41 def __init__(self, xrn, gid_filename, privkey_filename):
42 hrn, type = urn_to_hrn(xrn)
44 self.set_gid_filename(gid_filename)
45 self.privkey_filename = privkey_filename
48 # Set the filename of the GID
50 # @param fn filename of file containing GID
52 def set_gid_filename(self, fn):
53 self.gid_filename = fn
54 self.gid_object = None
56 def get_privkey_filename(self):
57 return self.privkey_filename
59 def get_gid_filename(self):
60 return self.gid_filename
63 # Get the GID in the form of a GID object
65 def get_gid_object(self):
66 if not self.gid_object:
67 self.gid_object = GID(filename = self.gid_filename)
68 return self.gid_object
71 # Get the private key in the form of a Keypair object
73 def get_pkey_object(self):
74 return Keypair(filename = self.privkey_filename)
77 # Replace the GID with a new one. The file specified by gid_filename is
78 # overwritten with the new GID object
80 # @param gid object containing new GID
82 def update_gid_object(self, gid):
83 gid.save_to_file(self.gid_filename)
87 # The Hierarchy class is responsible for managing the tree of authorities.
88 # Each authority is a node in the tree and exists as an AuthInfo object.
90 # The tree is stored on disk in a hierarchical manner than reflects the
91 # structure of the tree. Each authority is a subdirectory, and each subdirectory
92 # contains the GID and pkey files for that authority (as well as
93 # subdirectories for each sub-authority)
97 # Create the hierarchy object.
99 # @param basedir the base directory to store the hierarchy in
101 def __init__(self, basedir = None):
102 self.config = Config()
104 basedir = os.path.join(self.config.SFA_DATA_DIR, "authorities")
105 self.basedir = basedir
107 # Given a hrn, return the filenames of the GID, private key
110 # @param xrn the human readable name of the authority (urn will be convertd to hrn)
112 def get_auth_filenames(self, xrn):
113 hrn, type = urn_to_hrn(xrn)
115 parent_hrn = get_authority(hrn)
116 directory = os.path.join(self.basedir, hrn.replace(".", "/"))
118 gid_filename = os.path.join(directory, leaf+".gid")
119 privkey_filename = os.path.join(directory, leaf+".pkey")
121 return (directory, gid_filename, privkey_filename)
124 # Check to see if an authority exists. An authority exists if it's disk
127 # @param the human readable name of the authority to check
129 def auth_exists(self, xrn):
130 hrn, type = urn_to_hrn(xrn)
131 (directory, gid_filename, privkey_filename) = \
132 self.get_auth_filenames(hrn)
134 return os.path.exists(gid_filename) and os.path.exists(privkey_filename)
137 # Create an authority. A private key for the authority and the associated
138 # GID are created and signed by the parent authority.
140 # @param xrn the human readable name of the authority to create (urn will be converted to hrn)
141 # @param create_parents if true, also create the parents if they do not exist
143 def create_auth(self, xrn, create_parents=False):
144 hrn, type = urn_to_hrn(str(xrn))
145 logger.debug("Hierarchy: creating authority: %s"% hrn)
147 # create the parent authority if necessary
148 parent_hrn = get_authority(hrn)
149 parent_urn = hrn_to_urn(parent_hrn, 'authority')
150 if (parent_hrn) and (not self.auth_exists(parent_urn)) and (create_parents):
151 self.create_auth(parent_urn, create_parents)
152 (directory, gid_filename, privkey_filename,) = \
153 self.get_auth_filenames(hrn)
155 # create the directory to hold the files
157 os.makedirs(directory)
158 # if the path already exists then pass
159 except OSError, (errno, strerr):
163 if os.path.exists(privkey_filename):
164 logger.debug("using existing key %r for authority %r"%(privkey_filename,hrn))
165 pkey = Keypair(filename = privkey_filename)
167 pkey = Keypair(create = True)
168 pkey.save_to_file(privkey_filename)
170 gid = self.create_gid(xrn, create_uuid(), pkey)
171 gid.save_to_file(gid_filename, save_parents=True)
173 def create_top_level_auth(self, hrn=None):
175 Create top level records (includes root and sub authorities (local/remote)
178 hrn = self.config.SFA_INTERFACE_HRN
179 # make sure parent exists
180 parent_hrn = get_authority(hrn)
183 if not parent_hrn == hrn:
184 self.create_top_level_auth(parent_hrn)
186 # create the authority if it doesnt alrady exist
187 if not self.auth_exists(hrn):
188 self.create_auth(hrn)
191 def get_interface_auth_info(self, create=True):
192 hrn = self.config.SFA_INTERFACE_HRN
193 if not self.auth_exists(hrn):
195 self.create_top_level_auth(hrn)
197 raise MissingAuthority(hrn)
198 return self.get_auth_info(hrn)
200 # Return the AuthInfo object for the specified authority. If the authority
201 # does not exist, then an exception is thrown. As a side effect, disk files
202 # and a subdirectory may be created to store the authority.
204 # @param xrn the human readable name of the authority to create (urn will be converted to hrn).
206 def get_auth_info(self, xrn):
207 hrn, type = urn_to_hrn(xrn)
208 if not self.auth_exists(hrn):
209 logger.warning("Hierarchy: missing authority - xrn=%s, hrn=%s"%(xrn,hrn))
210 raise MissingAuthority(hrn)
212 (directory, gid_filename, privkey_filename, ) = \
213 self.get_auth_filenames(hrn)
215 auth_info = AuthInfo(hrn, gid_filename, privkey_filename)
217 # check the GID and see if it needs to be refreshed
218 gid = auth_info.get_gid_object()
219 gid_refreshed = self.refresh_gid(gid)
220 if gid != gid_refreshed:
221 auth_info.update_gid_object(gid_refreshed)
226 # Create a new GID. The GID will be signed by the authority that is it's
227 # immediate parent in the hierarchy (and recursively, the parents' GID
228 # will be signed by its parent)
230 # @param hrn the human readable name to store in the GID
231 # @param uuid the unique identifier to store in the GID
232 # @param pkey the public key to store in the GID
234 def create_gid(self, xrn, uuid, pkey, CA=False):
235 hrn, type = urn_to_hrn(xrn)
238 parent_hrn = get_authority(hrn)
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 if hrn == self.config.SFA_INTERFACE_HRN or not parent_hrn:
246 # root or sub authority
247 gid.set_intermediate_ca(True)
248 elif type and 'authority' in type:
250 gid.set_intermediate_ca(True)
252 gid.set_intermediate_ca(True)
254 gid.set_intermediate_ca(False)
257 if not parent_hrn or hrn == self.config.SFA_INTERFACE_HRN:
258 # if there is no parent hrn, then it must be self-signed. this
259 # is where we terminate the recursion
260 gid.set_issuer(pkey, hrn)
262 # we need the parent's private key in order to sign this GID
263 parent_auth_info = self.get_auth_info(parent_hrn)
264 gid.set_issuer(parent_auth_info.get_pkey_object(), parent_auth_info.hrn)
265 gid.set_parent(parent_auth_info.get_gid_object())
274 # Refresh a GID. The primary use of this function is to refresh the
275 # the expiration time of the GID. It may also be used to change the HRN,
276 # UUID, or Public key of the GID.
278 # @param gid the GID to refresh
279 # @param hrn if !=None, change the hrn
280 # @param uuid if !=None, change the uuid
281 # @param pubkey if !=None, change the public key
283 def refresh_gid(self, gid, xrn=None, uuid=None, pubkey=None):
284 # TODO: compute expiration time of GID, refresh it if necessary
285 gid_is_expired = False
287 # update the gid if we need to
288 if gid_is_expired or xrn or uuid or pubkey:
293 uuid = gid.get_uuid()
295 pubkey = gid.get_pubkey()
297 gid = self.create_gid(xrn, uuid, pubkey)
302 # Retrieve an authority credential for an authority. The authority
303 # credential will contain the authority privilege and will be signed by
304 # the authority's parent.
306 # @param hrn the human readable name of the authority (urn is converted to hrn)
307 # @param authority type of credential to return (authority | sa | ma)
309 def get_auth_cred(self, xrn, kind="authority"):
310 hrn, type = urn_to_hrn(xrn)
311 auth_info = self.get_auth_info(hrn)
312 gid = auth_info.get_gid_object()
314 cred = Credential(subject=hrn)
315 cred.set_gid_caller(gid)
316 cred.set_gid_object(gid)
317 cred.set_privileges(kind)
318 cred.get_privileges().delegate_all_privileges(True)
319 #cred.set_pubkey(auth_info.get_gid_object().get_pubkey())
321 parent_hrn = get_authority(hrn)
322 if not parent_hrn or hrn == self.config.SFA_INTERFACE_HRN:
323 # if there is no parent hrn, then it must be self-signed. this
324 # is where we terminate the recursion
325 cred.set_issuer_keys(auth_info.get_privkey_filename(), auth_info.get_gid_filename())
327 # we need the parent's private key in order to sign this GID
328 parent_auth_info = self.get_auth_info(parent_hrn)
329 cred.set_issuer_keys(parent_auth_info.get_privkey_filename(), parent_auth_info.get_gid_filename())
332 cred.set_parent(self.get_auth_cred(parent_hrn, kind))
339 # Retrieve an authority ticket. An authority ticket is not actually a
340 # redeemable ticket, but only serves the purpose of being included as the
341 # parent of another ticket, in order to provide a chain of authentication
344 # This looks almost the same as get_auth_cred, but works for tickets
345 # XXX does similarity imply there should be more code re-use?
347 # @param xrn the human readable name of the authority (urn is converted to hrn)
349 def get_auth_ticket(self, xrn):
350 hrn, type = urn_to_hrn(xrn)
351 auth_info = self.get_auth_info(hrn)
352 gid = auth_info.get_gid_object()
354 ticket = SfaTicket(subject=hrn)
355 ticket.set_gid_caller(gid)
356 ticket.set_gid_object(gid)
357 ticket.set_delegate(True)
358 ticket.set_pubkey(auth_info.get_gid_object().get_pubkey())
360 parent_hrn = get_authority(hrn)
362 # if there is no parent hrn, then it must be self-signed. this
363 # is where we terminate the recursion
364 ticket.set_issuer(auth_info.get_pkey_object(), hrn)
366 # we need the parent's private key in order to sign this GID
367 parent_auth_info = self.get_auth_info(parent_hrn)
368 ticket.set_issuer(parent_auth_info.get_pkey_object(), parent_auth_info.hrn)
369 ticket.set_parent(self.get_auth_cred(parent_hrn))