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
17 from sfa.util.faults import *
18 from sfa.util.sfalogging import sfa_logger
19 from sfa.util.xrn import get_leaf, get_authority, hrn_to_urn, urn_to_hrn
20 from sfa.trust.certificate import Keypair
21 from sfa.trust.credential import Credential
22 from sfa.trust.gid import GID, create_uuid
23 from sfa.util.config import Config
24 from sfa.util.sfaticket import SfaTicket
27 # The AuthInfo class contains the information for an authority. This information
28 # includes the GID, private key, and database connection information.
34 privkey_filename = None
35 dbinfo_filename = None
38 # Initialize and authority object.
40 # @param xrn the human readable name of the authority (urn will be converted to hrn)
41 # @param gid_filename the filename containing the GID
42 # @param privkey_filename the filename containing the private key
43 # @param dbinfo_filename the filename containing the database info
45 def __init__(self, xrn, gid_filename, privkey_filename, dbinfo_filename):
46 hrn, type = urn_to_hrn(xrn)
48 self.set_gid_filename(gid_filename)
49 self.privkey_filename = privkey_filename
50 self.dbinfo_filename = dbinfo_filename
53 # Set the filename of the GID
55 # @param fn filename of file containing GID
57 def set_gid_filename(self, fn):
58 self.gid_filename = fn
59 self.gid_object = None
61 def get_privkey_filename(self):
62 return self.privkey_filename
64 def get_gid_filename(self):
65 return self.gid_filename
68 # Get the GID in the form of a GID object
70 def get_gid_object(self):
71 if not self.gid_object:
72 self.gid_object = GID(filename = self.gid_filename)
73 return self.gid_object
76 # Get the private key in the form of a Keypair object
78 def get_pkey_object(self):
79 return Keypair(filename = self.privkey_filename)
82 # Get the dbinfo in the form of a dictionary
85 f = file(self.dbinfo_filename)
91 # Replace the GID with a new one. The file specified by gid_filename is
92 # overwritten with the new GID object
94 # @param gid object containing new GID
96 def update_gid_object(self, gid):
97 gid.save_to_file(self.gid_filename)
101 # The Hierarchy class is responsible for managing the tree of authorities.
102 # Each authority is a node in the tree and exists as an AuthInfo object.
104 # The tree is stored on disk in a hierarchical manner than reflects the
105 # structure of the tree. Each authority is a subdirectory, and each subdirectory
106 # contains the GID, pkey, and dbinfo files for that authority (as well as
107 # subdirectories for each sub-authority)
111 # Create the hierarchy object.
113 # @param basedir the base directory to store the hierarchy in
115 def __init__(self, basedir = None):
117 self.config = Config()
118 basedir = os.path.join(self.config.SFA_DATA_DIR, "authorities")
119 self.basedir = basedir
121 # Given a hrn, return the filenames of the GID, private key, and dbinfo
124 # @param xrn the human readable name of the authority (urn will be convertd to hrn)
126 def get_auth_filenames(self, xrn):
127 hrn, type = urn_to_hrn(xrn)
129 parent_hrn = get_authority(hrn)
130 directory = os.path.join(self.basedir, hrn.replace(".", "/"))
132 gid_filename = os.path.join(directory, leaf+".gid")
133 privkey_filename = os.path.join(directory, leaf+".pkey")
134 dbinfo_filename = os.path.join(directory, leaf+".dbinfo")
136 return (directory, gid_filename, privkey_filename, dbinfo_filename)
139 # Check to see if an authority exists. An authority exists if it's disk
142 # @param the human readable name of the authority to check
144 def auth_exists(self, xrn):
145 hrn, type = urn_to_hrn(xrn)
146 (directory, gid_filename, privkey_filename, dbinfo_filename) = \
147 self.get_auth_filenames(hrn)
149 return os.path.exists(gid_filename) and \
150 os.path.exists(privkey_filename) and \
151 os.path.exists(dbinfo_filename)
154 # Create an authority. A private key for the authority and the associated
155 # GID are created and signed by the parent authority.
157 # @param xrn the human readable name of the authority to create (urn will be converted to hrn)
158 # @param create_parents if true, also create the parents if they do not exist
160 def create_auth(self, xrn, create_parents=False):
161 hrn, type = urn_to_hrn(xrn)
162 sfa_logger().debug("Hierarchy: creating authority: %s"% hrn)
164 # create the parent authority if necessary
165 parent_hrn = get_authority(hrn)
166 parent_urn = hrn_to_urn(parent_hrn, 'authority')
167 if (parent_hrn) and (not self.auth_exists(parent_urn)) and (create_parents):
168 self.create_auth(parent_urn, create_parents)
170 (directory, gid_filename, privkey_filename, dbinfo_filename) = \
171 self.get_auth_filenames(hrn)
173 # create the directory to hold the files
175 os.makedirs(directory)
176 # if the path already exists then pass
177 except OSError, (errno, strerr):
181 if os.path.exists(privkey_filename):
182 sfa_logger().debug("using existing key %r for authority %r"%(privkey_filename,hrn))
183 pkey = Keypair(filename = privkey_filename)
185 pkey = Keypair(create = True)
186 pkey.save_to_file(privkey_filename)
188 gid = self.create_gid(xrn, create_uuid(), pkey)
189 gid.save_to_file(gid_filename, save_parents=True)
191 # XXX TODO: think up a better way for the dbinfo to work
193 dbinfo = Config().get_plc_dbinfo()
194 dbinfo_file = file(dbinfo_filename, "w")
195 dbinfo_file.write(str(dbinfo))
199 # Return the AuthInfo object for the specified authority. If the authority
200 # does not exist, then an exception is thrown. As a side effect, disk files
201 # and a subdirectory may be created to store the authority.
203 # @param xrn the human readable name of the authority to create (urn will be converted to hrn).
205 def get_auth_info(self, xrn):
206 hrn, type = urn_to_hrn(xrn)
207 if not self.auth_exists(hrn):
208 sfa_logger().warning("Hierarchy: mising authority - xrn=%s, hrn=%s"%(xrn,hrn))
209 raise MissingAuthority(hrn)
211 (directory, gid_filename, privkey_filename, dbinfo_filename) = \
212 self.get_auth_filenames(hrn)
214 auth_info = AuthInfo(hrn, gid_filename, privkey_filename, dbinfo_filename)
216 # check the GID and see if it needs to be refreshed
217 gid = auth_info.get_gid_object()
218 gid_refreshed = self.refresh_gid(gid)
219 if gid != gid_refreshed:
220 auth_info.update_gid_object(gid_refreshed)
225 # Create a new GID. The GID will be signed by the authority that is it's
226 # immediate parent in the hierarchy (and recursively, the parents' GID
227 # will be signed by its parent)
229 # @param hrn the human readable name to store in the GID
230 # @param uuid the unique identifier to store in the GID
231 # @param pkey the public key to store in the GID
233 def create_gid(self, xrn, uuid, pkey):
234 hrn, type = urn_to_hrn(xrn)
235 # Using hrn_to_urn() here to make sure the urn is in the right format
236 # If xrn was a hrn instead of a urn, then the gid's urn will be
238 urn = hrn_to_urn(hrn, type)
239 gid = GID(subject=hrn, uuid=uuid, hrn=hrn, urn=urn)
241 parent_hrn = get_authority(hrn)
242 if not parent_hrn or hrn == self.config.SFA_INTERFACE_HRN:
243 # if there is no parent hrn, then it must be self-signed. this
244 # is where we terminate the recursion
245 gid.set_issuer(pkey, hrn)
247 # we need the parent's private key in order to sign this GID
248 parent_auth_info = self.get_auth_info(parent_hrn)
249 gid.set_issuer(parent_auth_info.get_pkey_object(), parent_auth_info.hrn)
250 gid.set_parent(parent_auth_info.get_gid_object())
251 gid.set_intermediate_ca(True)
260 # Refresh a GID. The primary use of this function is to refresh the
261 # the expiration time of the GID. It may also be used to change the HRN,
262 # UUID, or Public key of the GID.
264 # @param gid the GID to refresh
265 # @param hrn if !=None, change the hrn
266 # @param uuid if !=None, change the uuid
267 # @param pubkey if !=None, change the public key
269 def refresh_gid(self, gid, xrn=None, uuid=None, pubkey=None):
270 # TODO: compute expiration time of GID, refresh it if necessary
271 gid_is_expired = False
273 # update the gid if we need to
274 if gid_is_expired or xrn or uuid or pubkey:
279 uuid = gid.get_uuid()
281 pubkey = gid.get_pubkey()
283 gid = self.create_gid(xrn, uuid, pubkey)
288 # Retrieve an authority credential for an authority. The authority
289 # credential will contain the authority privilege and will be signed by
290 # the authority's parent.
292 # @param hrn the human readable name of the authority (urn is converted to hrn)
293 # @param authority type of credential to return (authority | sa | ma)
295 def get_auth_cred(self, xrn, kind="authority"):
296 hrn, type = urn_to_hrn(xrn)
297 auth_info = self.get_auth_info(hrn)
298 gid = auth_info.get_gid_object()
300 cred = Credential(subject=hrn)
301 cred.set_gid_caller(gid)
302 cred.set_gid_object(gid)
303 cred.set_privileges(kind)
304 cred.get_privileges().delegate_all_privileges(True)
305 #cred.set_pubkey(auth_info.get_gid_object().get_pubkey())
307 parent_hrn = get_authority(hrn)
308 if not parent_hrn or hrn == self.config.SFA_INTERFACE_HRN:
309 # if there is no parent hrn, then it must be self-signed. this
310 # is where we terminate the recursion
311 cred.set_issuer_keys(auth_info.get_privkey_filename(), auth_info.get_gid_filename())
313 # we need the parent's private key in order to sign this GID
314 parent_auth_info = self.get_auth_info(parent_hrn)
315 cred.set_issuer_keys(parent_auth_info.get_privkey_filename(), parent_auth_info.get_gid_filename())
318 cred.set_parent(self.get_auth_cred(parent_hrn, kind))
325 # Retrieve an authority ticket. An authority ticket is not actually a
326 # redeemable ticket, but only serves the purpose of being included as the
327 # parent of another ticket, in order to provide a chain of authentication
330 # This looks almost the same as get_auth_cred, but works for tickets
331 # XXX does similarity imply there should be more code re-use?
333 # @param xrn the human readable name of the authority (urn is converted to hrn)
335 def get_auth_ticket(self, xrn):
336 hrn, type = urn_to_hrn(xrn)
337 auth_info = self.get_auth_info(hrn)
338 gid = auth_info.get_gid_object()
340 ticket = SfaTicket(subject=hrn)
341 ticket.set_gid_caller(gid)
342 ticket.set_gid_object(gid)
343 ticket.set_delegate(True)
344 ticket.set_pubkey(auth_info.get_gid_object().get_pubkey())
346 parent_hrn = get_authority(hrn)
348 # if there is no parent hrn, then it must be self-signed. this
349 # is where we terminate the recursion
350 ticket.set_issuer(auth_info.get_pkey_object(), hrn)
352 # we need the parent's private key in order to sign this GID
353 parent_auth_info = self.get_auth_info(parent_hrn)
354 ticket.set_issuer(parent_auth_info.get_pkey_object(), parent_auth_info.hrn)
355 ticket.set_parent(self.get_auth_cred(parent_hrn))