#---------------------------------------------------------------------- # Copyright (c) 2008 Board of Trustees, Princeton University # # Permission is hereby granted, free of charge, to any person obtaining # a copy of this software and/or hardware specification (the "Work") to # deal in the Work without restriction, including without limitation the # rights to use, copy, modify, merge, publish, distribute, sublicense, # and/or sell copies of the Work, and to permit persons to whom the Work # is furnished to do so, subject to the following conditions: # # The above copyright notice and this permission notice shall be # included in all copies or substantial portions of the Work. # # THE WORK IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS # OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT # HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, # WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, # OUT OF OR IN CONNECTION WITH THE WORK OR THE USE OR OTHER DEALINGS # IN THE WORK. #---------------------------------------------------------------------- ## # Implements SFA GID. GIDs are based on certificates, and the GID class is a # descendant of the certificate class. ## import uuid import xmlrpc.client from sfa.trust.certificate import Certificate from sfa.util.faults import GidInvalidParentHrn, GidParentHrn from sfa.util.xrn import hrn_to_urn, urn_to_hrn, hrn_authfor_hrn from sfa.util.sfalogging import logger ## # Create a new uuid. Returns the UUID as a string. def create_uuid(): return str(uuid.uuid4().int) ## # GID is a tuple: # (uuid, urn, public_key) # # UUID is a unique identifier and is created by the python uuid module # (or the utility function create_uuid() in gid.py). # # HRN is a human readable name. It is a dotted form similar to a backward domain # name. For example, planetlab.us.arizona.bakers. # # URN is a human readable identifier of form: # "urn:publicid:IDN+toplevelauthority[:sub-auth.]*[\res. type]\ +object name" # For example, urn:publicid:IDN+planetlab:us:arizona+user+bakers # # PUBLIC_KEY is the public key of the principal identified by the UUID/HRN. # It is a Keypair object as defined in the cert.py module. # # It is expected that there is a one-to-one pairing between UUIDs and HRN, # but it is uncertain how this would be inforced or if it needs to be enforced. # # These fields are encoded using xmlrpc into the subjectAltName field of the # x509 certificate. Note: Call encode() once the fields have been filled in # to perform this encoding. class GID(Certificate): ## # Create a new GID object # # @param create If true, create the X509 certificate # @param subject If subject!=None, create the X509 cert and set the subject name # @param string If string!=None, load the GID from a string # @param filename If filename!=None, load the GID from a file # @param lifeDays life of GID in days - default is 1825==5 years # @param email Email address to put in subjectAltName - default is None def __init__(self, create=False, subject=None, string=None, filename=None, uuid=None, hrn=None, urn=None, lifeDays=1825, email=None): self.uuid = None self.hrn = None self.urn = None self.email = None # for adding to the SubjectAltName Certificate.__init__(self, lifeDays, create, subject, string, filename) if subject: logger.debug("Creating GID for subject: %s" % subject) if uuid: self.uuid = int(uuid) if hrn: self.hrn = hrn self.urn = hrn_to_urn(hrn, 'unknown') if urn: self.urn = urn self.hrn, type = urn_to_hrn(urn) if email: logger.debug("Creating GID for subject using email: %s" % email) self.set_email(email) def set_uuid(self, uuid): if isinstance(uuid, str): self.uuid = int(uuid) else: self.uuid = uuid def get_uuid(self): if not self.uuid: self.decode() return self.uuid def set_hrn(self, hrn): self.hrn = hrn def get_hrn(self): if not self.hrn: self.decode() return self.hrn def set_urn(self, urn): self.urn = urn self.hrn, type = urn_to_hrn(urn) def get_urn(self): if not self.urn: self.decode() return self.urn # Will be stuffed into subjectAltName def set_email(self, email): self.email = email def get_email(self): if not self.email: self.decode() return self.email def get_type(self): if not self.urn: self.decode() _, t = urn_to_hrn(self.urn) return t ## # Encode the GID fields and package them into the subject-alt-name field # of the X509 certificate. This must be called prior to signing the # certificate. It may only be called once per certificate. def encode(self): if self.urn: urn = self.urn else: urn = hrn_to_urn(self.hrn, None) string = "URI:" + urn if self.uuid: string += ", " + "URI:" + uuid.UUID(int=self.uuid).urn if self.email: string += ", " + "email:" + self.email self.set_data(string, 'subjectAltName') ## # Decode the subject-alt-name field of the X509 certificate into the # fields of the GID. This is automatically called by the various get_*() # functions in this class. def decode(self): data = self.get_data('subjectAltName') dict = {} if data: if data.lower().startswith('uri:http://'): dict = xmlrpc.client.loads(data[11:])[0][0] else: spl = data.split(', ') for val in spl: if val.lower().startswith('uri:urn:uuid:'): dict['uuid'] = uuid.UUID(val[4:]).int elif val.lower().startswith('uri:urn:publicid:idn+'): dict['urn'] = val[4:] elif val.lower().startswith('email:'): # FIXME: Ensure there isn't cruft in that address... # EG look for email:copy,.... dict['email'] = val[6:] self.uuid = dict.get("uuid", None) self.urn = dict.get("urn", None) self.hrn = dict.get("hrn", None) self.email = dict.get("email", None) if self.urn: self.hrn = urn_to_hrn(self.urn)[0] ## # Dump the credential to stdout. # # @param indent specifies a number of spaces to indent the output # @param dump_parents If true, also dump the parents of the GID def dump(self, *args, **kwargs): print(self.dump_string(*args, **kwargs)) def dump_string(self, indent=0, dump_parents=False): result = " " * (indent - 2) + "GID\n" result += " " * indent + "hrn:" + str(self.get_hrn()) + "\n" result += " " * indent + "urn:" + str(self.get_urn()) + "\n" result += " " * indent + "uuid:" + str(self.get_uuid()) + "\n" if self.get_email() is not None: result += " " * indent + "email:" + str(self.get_email()) + "\n" filename = self.get_filename() if filename: result += "Filename %s\n" % filename if self.parent and dump_parents: result += " " * indent + "parent:\n" result += self.parent.dump_string(indent + 4, dump_parents) return result ## # Verify the chain of authenticity of the GID. First perform the checks # of the certificate class (verifying that each parent signs the child, # etc). In addition, GIDs also confirm that the parent's HRN is a prefix # of the child's HRN, and the parent is of type 'authority'. # # Verifying these prefixes prevents a rogue authority from signing a GID # for a principal that is not a member of that authority. For example, # planetlab.us.arizona cannot sign a GID for planetlab.us.princeton.foo. def verify_chain(self, trusted_certs=None): logger.debug(10*'=' + " GID.verify_chain with {} trusted certs" .format(len(trusted_certs))) logger.debug("on {}".format(self.pretty_name())) # do the normal certificate verification stuff trusted_root = Certificate.verify_chain(self, trusted_certs) if self.parent: # make sure the parent's hrn is a prefix of the child's hrn if not hrn_authfor_hrn(self.parent.get_hrn(), self.get_hrn()): raise GidParentHrn( "This cert HRN {} isn't in the namespace for parent HRN {}" .format(self.get_hrn(), self.parent.get_hrn())) # Parent must also be an authority (of some type) to sign a GID # There are multiple types of authority - accept them all here if not self.parent.get_type().find('authority') == 0: raise GidInvalidParentHrn( "This cert {}'s parent {} is not an authority (is a %{})" .format(self.get_hrn(), self.parent.get_hrn(), self.parent.get_type())) # Then recurse up the chain - ensure the parent is a trusted # root or is in the namespace of a trusted root self.parent.verify_chain(trusted_certs) else: # make sure that the trusted root's hrn is a prefix of the child's trusted_gid = GID(string=trusted_root.save_to_string()) trusted_type = trusted_gid.get_type() trusted_hrn = trusted_gid.get_hrn() # if trusted_type == 'authority': # trusted_hrn = trusted_hrn[:trusted_hrn.rindex('.')] cur_hrn = self.get_hrn() if not hrn_authfor_hrn(trusted_hrn, cur_hrn): raise GidParentHrn( "Trusted root with HRN {} isn't a namespace authority for this cert: {}" .format(trusted_hrn, cur_hrn)) # There are multiple types of authority - accept them all here if not trusted_type.find('authority') == 0: raise GidInvalidParentHrn( "This cert {}'s trusted root signer {} is not an authority (is a {})" .format(self.get_hrn(), trusted_hrn, trusted_type))