1 #----------------------------------------------------------------------
2 # Copyright (c) 2008 Board of Trustees, Princeton University
4 # Permission is hereby granted, free of charge, to any person obtaining
5 # a copy of this software and/or hardware specification (the "Work") to
6 # deal in the Work without restriction, including without limitation the
7 # rights to use, copy, modify, merge, publish, distribute, sublicense,
8 # and/or sell copies of the Work, and to permit persons to whom the Work
9 # is furnished to do so, subject to the following conditions:
11 # The above copyright notice and this permission notice shall be
12 # included in all copies or substantial portions of the Work.
14 # THE WORK IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
15 # OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
16 # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
17 # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
18 # HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
19 # WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 # OUT OF OR IN CONNECTION WITH THE WORK OR THE USE OR OTHER DEALINGS
22 #----------------------------------------------------------------------
24 # Implements SFA Credentials
26 # Credentials are signed XML files that assign a subject gid privileges to an object gid
30 from types import StringTypes
32 from StringIO import StringIO
33 from tempfile import mkstemp
34 from xml.dom.minidom import Document, parseString
38 from lxml import etree
43 from xml.parsers.expat import ExpatError
45 from sfa.util.faults import CredentialNotVerifiable, ChildRightsNotSubsetOfParent
46 from sfa.util.sfalogging import logger
47 from sfa.util.sfatime import utcparse
48 from sfa.trust.credential_legacy import CredentialLegacy
49 from sfa.trust.rights import Right, Rights, determine_rights
50 from sfa.trust.gid import GID
51 from sfa.util.xrn import urn_to_hrn, hrn_authfor_hrn
54 DEFAULT_CREDENTIAL_LIFETIME = 86400 * 31
58 # . make privs match between PG and PL
59 # . Need to add support for other types of credentials, e.g. tickets
60 # . add namespaces to signed-credential element?
62 signature_template = \
64 <Signature xml:id="Sig_%s" xmlns="http://www.w3.org/2000/09/xmldsig#">
66 <CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
67 <SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/>
70 <Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature" />
72 <DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>
73 <DigestValue></DigestValue>
88 # PG formats the template (whitespace) slightly differently.
89 # Note that they don't include the xmlns in the template, but add it later.
90 # Otherwise the two are equivalent.
91 #signature_template_as_in_pg = \
93 #<Signature xml:id="Sig_%s" >
95 # <CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
96 # <SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/>
97 # <Reference URI="#%s">
99 # <Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature" />
101 # <DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>
102 # <DigestValue></DigestValue>
109 # <X509IssuerSerial/>
118 # Convert a string into a bool
119 # used to convert an xsd:boolean to a Python boolean
121 if str.lower() in ['true','1']:
127 # Utility function to get the text of an XML element
129 def getTextNode(element, subele):
130 sub = element.getElementsByTagName(subele)[0]
131 if len(sub.childNodes) > 0:
132 return sub.childNodes[0].nodeValue
137 # Utility function to set the text of an XML element
138 # It creates the element, adds the text to it,
139 # and then appends it to the parent.
141 def append_sub(doc, parent, element, text):
142 ele = doc.createElement(element)
143 ele.appendChild(doc.createTextNode(text))
144 parent.appendChild(ele)
147 # Signature contains information about an xmlsec1 signature
148 # for a signed-credential
151 class Signature(object):
153 def __init__(self, string=None):
155 self.issuer_gid = None
172 def set_refid(self, id):
175 def get_issuer_gid(self):
180 def set_issuer_gid(self, gid):
185 doc = parseString(self.xml)
187 logger.log_exc ("Failed to parse credential, %s"%self.xml)
189 sig = doc.getElementsByTagName("Signature")[0]
190 self.set_refid(sig.getAttribute("xml:id").strip("Sig_"))
191 keyinfo = sig.getElementsByTagName("X509Data")[0]
192 szgid = getTextNode(keyinfo, "X509Certificate")
193 szgid = "-----BEGIN CERTIFICATE-----\n%s\n-----END CERTIFICATE-----" % szgid
194 self.set_issuer_gid(GID(string=szgid))
197 self.xml = signature_template % (self.get_refid(), self.get_refid())
201 # A credential provides a caller gid with privileges to an object gid.
202 # A signed credential is signed by the object's authority.
204 # Credentials are encoded in one of two ways. The legacy style places
205 # it in the subjectAltName of an X509 certificate. The new credentials
206 # are placed in signed XML.
209 # In general, a signed credential obtained externally should
210 # not be changed else the signature is no longer valid. So, once
211 # you have loaded an existing signed credential, do not call encode() or sign() on it.
213 def filter_creds_by_caller(creds, caller_hrn_list):
215 Returns a list of creds who's gid caller matches the
218 if not isinstance(creds, list): creds = [creds]
219 if not isinstance(caller_hrn_list, list):
220 caller_hrn_list = [caller_hrn_list]
224 tmp_cred = Credential(string=cred)
225 if tmp_cred.get_gid_caller().get_hrn() in caller_hrn_list:
226 caller_creds.append(cred)
230 class Credential(object):
233 # Create a Credential object
235 # @param create If true, create a blank x509 certificate
236 # @param subject If subject!=None, create an x509 cert with the subject name
237 # @param string If string!=None, load the credential from the string
238 # @param filename If filename!=None, load the credential from the file
239 # FIXME: create and subject are ignored!
240 def __init__(self, create=False, subject=None, string=None, filename=None):
241 self.gidCaller = None
242 self.gidObject = None
243 self.expiration = None
244 self.privileges = None
245 self.issuer_privkey = None
246 self.issuer_gid = None
247 self.issuer_pubkey = None
249 self.signature = None
254 # Check if this is a legacy credential, translate it if so
255 if string or filename:
259 str = file(filename).read()
261 if str.strip().startswith("-----"):
262 self.legacy = CredentialLegacy(False,string=str)
263 self.translate_legacy(str)
268 # Find an xmlsec1 path
269 self.xmlsec_path = ''
270 paths = ['/usr/bin','/usr/local/bin','/bin','/opt/bin','/opt/local/bin']
272 if os.path.isfile(path + '/' + 'xmlsec1'):
273 self.xmlsec_path = path + '/' + 'xmlsec1'
276 def get_subject(self):
277 if not self.gidObject:
279 return self.gidObject.get_printable_subject()
281 # sounds like this should be __repr__ instead ??
282 def get_summary_tostring(self):
283 if not self.gidObject:
285 obj = self.gidObject.get_printable_subject()
286 caller = self.gidCaller.get_printable_subject()
287 exp = self.get_expiration()
288 # Summarize the rights too? The issuer?
289 return "[ Grant %s rights on %s until %s ]" % (caller, obj, exp)
291 def get_signature(self):
292 if not self.signature:
294 return self.signature
296 def set_signature(self, sig):
301 # Translate a legacy credential into a new one
303 # @param String of the legacy credential
305 def translate_legacy(self, str):
306 legacy = CredentialLegacy(False,string=str)
307 self.gidCaller = legacy.get_gid_caller()
308 self.gidObject = legacy.get_gid_object()
309 lifetime = legacy.get_lifetime()
311 self.set_expiration(datetime.datetime.utcnow() + datetime.timedelta(seconds=DEFAULT_CREDENTIAL_LIFETIME))
313 self.set_expiration(int(lifetime))
314 self.lifeTime = legacy.get_lifetime()
315 self.set_privileges(legacy.get_privileges())
316 self.get_privileges().delegate_all_privileges(legacy.get_delegate())
319 # Need the issuer's private key and name
320 # @param key Keypair object containing the private key of the issuer
321 # @param gid GID of the issuing authority
323 def set_issuer_keys(self, privkey, gid):
324 self.issuer_privkey = privkey
325 self.issuer_gid = gid
329 # Set this credential's parent
330 def set_parent(self, cred):
335 # set the GID of the caller
337 # @param gid GID object of the caller
339 def set_gid_caller(self, gid):
341 # gid origin caller is the caller's gid by default
342 self.gidOriginCaller = gid
345 # get the GID of the object
347 def get_gid_caller(self):
348 if not self.gidCaller:
350 return self.gidCaller
353 # set the GID of the object
355 # @param gid GID object of the object
357 def set_gid_object(self, gid):
361 # get the GID of the object
363 def get_gid_object(self):
364 if not self.gidObject:
366 return self.gidObject
371 # Expiration: an absolute UTC time of expiration (as either an int or string or datetime)
373 def set_expiration(self, expiration):
374 if isinstance(expiration, (int, float)):
375 self.expiration = datetime.datetime.fromtimestamp(expiration)
376 elif isinstance (expiration, datetime.datetime):
377 self.expiration = expiration
378 elif isinstance (expiration, StringTypes):
379 self.expiration = utcparse (expiration)
381 logger.error ("unexpected input type in Credential.set_expiration")
385 # get the lifetime of the credential (always in datetime format)
387 def get_expiration(self):
388 if not self.expiration:
390 # at this point self.expiration is normalized as a datetime - DON'T call utcparse again
391 return self.expiration
395 def get_lifetime(self):
396 return self.get_expiration()
401 # @param privs either a comma-separated list of privileges of a Rights object
403 def set_privileges(self, privs):
404 if isinstance(privs, str):
405 self.privileges = Rights(string = privs)
407 self.privileges = privs
411 # return the privileges as a Rights object
413 def get_privileges(self):
414 if not self.privileges:
416 return self.privileges
419 # determine whether the credential allows a particular operation to be
422 # @param op_name string specifying name of operation ("lookup", "update", etc)
424 def can_perform(self, op_name):
425 rights = self.get_privileges()
430 return rights.can_perform(op_name)
434 # Encode the attributes of the credential into an XML string
435 # This should be done immediately before signing the credential.
437 # In general, a signed credential obtained externally should
438 # not be changed else the signature is no longer valid. So, once
439 # you have loaded an existing signed credential, do not call encode() or sign() on it.
442 # Create the XML document
444 signed_cred = doc.createElement("signed-credential")
447 # Note that credential/policy.xsd are really the PG schemas
449 # Note that delegation of credentials between the 2 only really works
450 # cause those schemas are identical.
451 # Also note these PG schemas talk about PG tickets and CM policies.
452 signed_cred.setAttribute("xmlns:xsi", "http://www.w3.org/2001/XMLSchema-instance")
453 signed_cred.setAttribute("xsi:noNamespaceSchemaLocation", "http://www.planet-lab.org/resources/sfa/credential.xsd")
454 signed_cred.setAttribute("xsi:schemaLocation", "http://www.planet-lab.org/resources/sfa/ext/policy/1 http://www.planet-lab.org/resources/sfa/ext/policy/1/policy.xsd")
456 # PG says for those last 2:
457 # signed_cred.setAttribute("xsi:noNamespaceSchemaLocation", "http://www.protogeni.net/resources/credential/credential.xsd")
458 # signed_cred.setAttribute("xsi:schemaLocation", "http://www.protogeni.net/resources/credential/ext/policy/1 http://www.protogeni.net/resources/credential/ext/policy/1/policy.xsd")
460 doc.appendChild(signed_cred)
462 # Fill in the <credential> bit
463 cred = doc.createElement("credential")
464 cred.setAttribute("xml:id", self.get_refid())
465 signed_cred.appendChild(cred)
466 append_sub(doc, cred, "type", "privilege")
467 append_sub(doc, cred, "serial", "8")
468 append_sub(doc, cred, "owner_gid", self.gidCaller.save_to_string())
469 append_sub(doc, cred, "owner_urn", self.gidCaller.get_urn())
470 append_sub(doc, cred, "target_gid", self.gidObject.save_to_string())
471 append_sub(doc, cred, "target_urn", self.gidObject.get_urn())
472 append_sub(doc, cred, "uuid", "")
473 if not self.expiration:
474 self.set_expiration(datetime.datetime.utcnow() + datetime.timedelta(seconds=DEFAULT_CREDENTIAL_LIFETIME))
475 self.expiration = self.expiration.replace(microsecond=0)
476 append_sub(doc, cred, "expires", self.expiration.isoformat())
477 privileges = doc.createElement("privileges")
478 cred.appendChild(privileges)
481 rights = self.get_privileges()
482 for right in rights.rights:
483 priv = doc.createElement("privilege")
484 append_sub(doc, priv, "name", right.kind)
485 append_sub(doc, priv, "can_delegate", str(right.delegate).lower())
486 privileges.appendChild(priv)
488 # Add the parent credential if it exists
490 sdoc = parseString(self.parent.get_xml())
491 # If the root node is a signed-credential (it should be), then
492 # get all its attributes and attach those to our signed_cred
494 # Specifically, PG and PLadd attributes for namespaces (which is reasonable),
495 # and we need to include those again here or else their signature
496 # no longer matches on the credential.
497 # We expect three of these, but here we copy them all:
498 # signed_cred.setAttribute("xmlns:xsi", "http://www.w3.org/2001/XMLSchema-instance")
499 # and from PG (PL is equivalent, as shown above):
500 # signed_cred.setAttribute("xsi:noNamespaceSchemaLocation", "http://www.protogeni.net/resources/credential/credential.xsd")
501 # signed_cred.setAttribute("xsi:schemaLocation", "http://www.protogeni.net/resources/credential/ext/policy/1 http://www.protogeni.net/resources/credential/ext/policy/1/policy.xsd")
504 # PL now also declares these, with different URLs, so
505 # the code notices those attributes already existed with
506 # different values, and complains.
507 # This happens regularly on delegation now that PG and
508 # PL both declare the namespace with different URLs.
509 # If the content ever differs this is a problem,
510 # but for now it works - different URLs (values in the attributes)
511 # but the same actual schema, so using the PG schema
512 # on delegated-to-PL credentials works fine.
514 # Note: you could also not copy attributes
515 # which already exist. It appears that both PG and PL
516 # will actually validate a slicecred with a parent
517 # signed using PG namespaces and a child signed with PL
518 # namespaces over the whole thing. But I don't know
519 # if that is a bug in xmlsec1, an accident since
520 # the contents of the schemas are the same,
521 # or something else, but it seems odd. And this works.
522 parentRoot = sdoc.documentElement
523 if parentRoot.tagName == "signed-credential" and parentRoot.hasAttributes():
524 for attrIx in range(0, parentRoot.attributes.length):
525 attr = parentRoot.attributes.item(attrIx)
526 # returns the old attribute of same name that was
528 # Below throws InUse exception if we forgot to clone the attribute first
529 oldAttr = signed_cred.setAttributeNode(attr.cloneNode(True))
530 if oldAttr and oldAttr.value != attr.value:
531 msg = "Delegating cred from owner %s to %s over %s replaced attribute %s value '%s' with '%s'" % (self.parent.gidCaller.get_urn(), self.gidCaller.get_urn(), self.gidObject.get_urn(), oldAttr.name, oldAttr.value, attr.value)
533 #raise CredentialNotVerifiable("Can't encode new valid delegated credential: %s" % msg)
535 p_cred = doc.importNode(sdoc.getElementsByTagName("credential")[0], True)
536 p = doc.createElement("parent")
537 p.appendChild(p_cred)
539 # done handling parent credential
541 # Create the <signatures> tag
542 signatures = doc.createElement("signatures")
543 signed_cred.appendChild(signatures)
545 # Add any parent signatures
547 for cur_cred in self.get_credential_list()[1:]:
548 sdoc = parseString(cur_cred.get_signature().get_xml())
549 ele = doc.importNode(sdoc.getElementsByTagName("Signature")[0], True)
550 signatures.appendChild(ele)
552 # Get the finished product
553 self.xml = doc.toxml()
556 def save_to_random_tmp_file(self):
557 fp, filename = mkstemp(suffix='cred', text=True)
558 fp = os.fdopen(fp, "w")
559 self.save_to_file(filename, save_parents=True, filep=fp)
562 def save_to_file(self, filename, save_parents=True, filep=None):
568 f = open(filename, "w")
572 def save_to_string(self, save_parents=True):
582 def set_refid(self, rid):
586 # Figure out what refids exist, and update this credential's id
587 # so that it doesn't clobber the others. Returns the refids of
590 def updateRefID(self):
592 self.set_refid('ref0')
597 next_cred = self.parent
599 refs.append(next_cred.get_refid())
601 next_cred = next_cred.parent
606 # Find a unique refid for this credential
607 rid = self.get_refid()
610 rid = "ref%d" % (val + 1)
615 # Return the set of parent credential ref ids
624 # Sign the XML file created by encode()
627 # In general, a signed credential obtained externally should
628 # not be changed else the signature is no longer valid. So, once
629 # you have loaded an existing signed credential, do not call encode() or sign() on it.
632 if not self.issuer_privkey or not self.issuer_gid:
634 doc = parseString(self.get_xml())
635 sigs = doc.getElementsByTagName("signatures")[0]
637 # Create the signature template to be signed
638 signature = Signature()
639 signature.set_refid(self.get_refid())
640 sdoc = parseString(signature.get_xml())
641 sig_ele = doc.importNode(sdoc.getElementsByTagName("Signature")[0], True)
642 sigs.appendChild(sig_ele)
644 self.xml = doc.toxml()
647 # Split the issuer GID into multiple certificates if it's a chain
648 chain = GID(filename=self.issuer_gid)
651 gid_files.append(chain.save_to_random_tmp_file(False))
652 if chain.get_parent():
653 chain = chain.get_parent()
658 # Call out to xmlsec1 to sign it
659 ref = 'Sig_%s' % self.get_refid()
660 filename = self.save_to_random_tmp_file()
661 signed = os.popen('%s --sign --node-id "%s" --privkey-pem %s,%s %s' \
662 % (self.xmlsec_path, ref, self.issuer_privkey, ",".join(gid_files), filename)).read()
665 for gid_file in gid_files:
670 # This is no longer a legacy credential
679 # Retrieve the attributes of the credential from the XML.
680 # This is automatically called by the various get_* methods of
681 # this class and should not need to be called explicitly.
686 doc = parseString(self.xml)
688 signed_cred = doc.getElementsByTagName("signed-credential")
690 # Is this a signed-cred or just a cred?
691 if len(signed_cred) > 0:
692 creds = signed_cred[0].getElementsByTagName("credential")
693 signatures = signed_cred[0].getElementsByTagName("signatures")
694 if len(signatures) > 0:
695 sigs = signatures[0].getElementsByTagName("Signature")
697 creds = doc.getElementsByTagName("credential")
699 if creds is None or len(creds) == 0:
700 # malformed cred file
701 raise CredentialNotVerifiable("Malformed XML: No credential tag found")
703 # Just take the first cred if there are more than one
706 self.set_refid(cred.getAttribute("xml:id"))
707 self.set_expiration(utcparse(getTextNode(cred, "expires")))
708 self.gidCaller = GID(string=getTextNode(cred, "owner_gid"))
709 self.gidObject = GID(string=getTextNode(cred, "target_gid"))
713 privs = cred.getElementsByTagName("privileges")[0]
715 for priv in privs.getElementsByTagName("privilege"):
716 kind = getTextNode(priv, "name")
717 deleg = str2bool(getTextNode(priv, "can_delegate"))
719 # Convert * into the default privileges for the credential's type
720 # Each inherits the delegatability from the * above
721 _ , type = urn_to_hrn(self.gidObject.get_urn())
722 rl = determine_rights(type, self.gidObject.get_urn())
727 rlist.add(Right(kind.strip(), deleg))
728 self.set_privileges(rlist)
732 parent = cred.getElementsByTagName("parent")
734 parent_doc = parent[0].getElementsByTagName("credential")[0]
735 parent_xml = parent_doc.toxml()
736 self.parent = Credential(string=parent_xml)
739 # Assign the signatures to the credentials
741 Sig = Signature(string=sig.toxml())
743 for cur_cred in self.get_credential_list():
744 if cur_cred.get_refid() == Sig.get_refid():
745 cur_cred.set_signature(Sig)
750 # trusted_certs: A list of trusted GID filenames (not GID objects!)
751 # Chaining is not supported within the GIDs by xmlsec1.
753 # trusted_certs_required: Should usually be true. Set False means an
754 # empty list of trusted_certs would still let this method pass.
755 # It just skips xmlsec1 verification et al. Only used by some utils
758 # . All of the signatures are valid and that the issuers trace back
759 # to trusted roots (performed by xmlsec1)
760 # . The XML matches the credential schema
761 # . That the issuer of the credential is the authority in the target's urn
762 # . In the case of a delegated credential, this must be true of the root
763 # . That all of the gids presented in the credential are valid
764 # . Including verifying GID chains, and includ the issuer
765 # . The credential is not expired
767 # -- For Delegates (credentials with parents)
768 # . The privileges must be a subset of the parent credentials
769 # . The privileges must have "can_delegate" set for each delegated privilege
770 # . The target gid must be the same between child and parents
771 # . The expiry time on the child must be no later than the parent
772 # . The signer of the child must be the owner of the parent
774 # -- Verify does *NOT*
775 # . ensure that an xmlrpc client's gid matches a credential gid, that
776 # must be done elsewhere
778 # @param trusted_certs: The certificates of trusted CA certificates
779 def verify(self, trusted_certs=None, schema=None, trusted_certs_required=True):
783 # validate against RelaxNG schema
784 if HAVELXML and not self.legacy:
785 if schema and os.path.exists(schema):
786 tree = etree.parse(StringIO(self.xml))
787 schema_doc = etree.parse(schema)
788 xmlschema = etree.XMLSchema(schema_doc)
789 if not xmlschema.validate(tree):
790 error = xmlschema.error_log.last_error
791 message = "%s: %s (line %s)" % (self.get_summary_tostring(), error.message, error.line)
792 raise CredentialNotVerifiable(message)
794 if trusted_certs_required and trusted_certs is None:
797 # trusted_cert_objects = [GID(filename=f) for f in trusted_certs]
798 trusted_cert_objects = []
799 ok_trusted_certs = []
800 # If caller explicitly passed in None that means skip cert chain validation.
801 # Strange and not typical
802 if trusted_certs is not None:
803 for f in trusted_certs:
805 # Failures here include unreadable files
807 trusted_cert_objects.append(GID(filename=f))
808 ok_trusted_certs.append(f)
809 except Exception, exc:
810 logger.error("Failed to load trusted cert from %s: %r", f, exc)
811 trusted_certs = ok_trusted_certs
813 # Use legacy verification if this is a legacy credential
815 self.legacy.verify_chain(trusted_cert_objects)
816 if self.legacy.client_gid:
817 self.legacy.client_gid.verify_chain(trusted_cert_objects)
818 if self.legacy.object_gid:
819 self.legacy.object_gid.verify_chain(trusted_cert_objects)
822 # make sure it is not expired
823 if self.get_expiration() < datetime.datetime.utcnow():
824 raise CredentialNotVerifiable("Credential %s expired at %s" % (self.get_summary_tostring(), self.expiration.isoformat()))
826 # Verify the signatures
827 filename = self.save_to_random_tmp_file()
828 if trusted_certs is not None:
829 cert_args = " ".join(['--trusted-pem %s' % x for x in trusted_certs])
831 # If caller explicitly passed in None that means skip cert chain validation.
832 # - Strange and not typical
833 if trusted_certs is not None:
834 # Verify the gids of this cred and of its parents
835 for cur_cred in self.get_credential_list():
836 cur_cred.get_gid_object().verify_chain(trusted_cert_objects)
837 cur_cred.get_gid_caller().verify_chain(trusted_cert_objects)
840 refs.append("Sig_%s" % self.get_refid())
842 parentRefs = self.updateRefID()
843 for ref in parentRefs:
844 refs.append("Sig_%s" % ref)
847 # If caller explicitly passed in None that means skip xmlsec1 validation.
848 # Strange and not typical
849 if trusted_certs is None:
852 # print "Doing %s --verify --node-id '%s' %s %s 2>&1" % \
853 # (self.xmlsec_path, ref, cert_args, filename)
854 verified = os.popen('%s --verify --node-id "%s" %s %s 2>&1' \
855 % (self.xmlsec_path, ref, cert_args, filename)).read()
856 if not verified.strip().startswith("OK"):
857 # xmlsec errors have a msg= which is the interesting bit.
858 mstart = verified.find("msg=")
860 if mstart > -1 and len(verified) > 4:
862 mend = verified.find('\\', mstart)
863 msg = verified[mstart:mend]
864 raise CredentialNotVerifiable("xmlsec1 error verifying cred %s using Signature ID %s: %s %s" % (self.get_summary_tostring(), ref, msg, verified.strip()))
867 # Verify the parents (delegation)
869 self.verify_parent(self.parent)
871 # Make sure the issuer is the target's authority, and is
873 self.verify_issuer(trusted_cert_objects)
877 # Creates a list of the credential and its parents, with the root
878 # (original delegated credential) as the last item in the list
879 def get_credential_list(self):
883 list.append(cur_cred)
885 cur_cred = cur_cred.parent
891 # Make sure the credential's target gid (a) was signed by or (b)
892 # is the same as the entity that signed the original credential,
893 # or (c) is an authority over the target's namespace.
894 # Also ensure that the credential issuer / signer itself has a valid
895 # GID signature chain (signed by an authority with namespace rights).
896 def verify_issuer(self, trusted_gids):
897 root_cred = self.get_credential_list()[-1]
898 root_target_gid = root_cred.get_gid_object()
899 root_cred_signer = root_cred.get_signature().get_issuer_gid()
902 # Allow non authority to sign target and cred about target.
904 # Why do we need to allow non authorities to sign?
905 # If in the target gid validation step we correctly
906 # checked that the target is only signed by an authority,
907 # then this is just a special case of case 3.
908 # This short-circuit is the common case currently -
909 # and cause GID validation doesn't check 'authority',
910 # this allows users to generate valid slice credentials.
911 if root_target_gid.is_signed_by_cert(root_cred_signer):
912 # cred signer matches target signer, return success
916 # Allow someone to sign credential about themeselves. Used?
917 # If not, remove this.
918 #root_target_gid_str = root_target_gid.save_to_string()
919 #root_cred_signer_str = root_cred_signer.save_to_string()
920 #if root_target_gid_str == root_cred_signer_str:
921 # # cred signer is target, return success
926 # root_cred_signer is not the target_gid
927 # So this is a different gid that we have not verified.
928 # xmlsec1 verified the cert chain on this already, but
929 # it hasn't verified that the gid meets the HRN namespace
931 # Below we'll ensure that it is an authority.
932 # But we haven't verified that it is _signed by_ an authority
933 # We also don't know if xmlsec1 requires that cert signers
936 # Note that if verify() gave us no trusted_gids then this
937 # call will fail. So skip it if we have no trusted_gids
938 if trusted_gids and len(trusted_gids) > 0:
939 root_cred_signer.verify_chain(trusted_gids)
941 logger.debug("No trusted gids. Cannot verify that cred signer is signed by a trusted authority. Skipping that check.")
943 # See if the signer is an authority over the domain of the target.
944 # There are multiple types of authority - accept them all here
945 # Maybe should be (hrn, type) = urn_to_hrn(root_cred_signer.get_urn())
946 root_cred_signer_type = root_cred_signer.get_type()
947 if (root_cred_signer_type.find('authority') == 0):
948 #logger.debug('Cred signer is an authority')
949 # signer is an authority, see if target is in authority's domain
950 signerhrn = root_cred_signer.get_hrn()
951 if hrn_authfor_hrn(signerhrn, root_target_gid.get_hrn()):
954 # We've required that the credential be signed by an authority
955 # for that domain. Reasonable and probably correct.
956 # A looser model would also allow the signer to be an authority
957 # in my control framework - eg My CA or CH. Even if it is not
958 # the CH that issued these, eg, user credentials.
960 # Give up, credential does not pass issuer verification
962 raise CredentialNotVerifiable("Could not verify credential owned by %s for object %s. Cred signer %s not the trusted authority for Cred target %s" % (self.gidCaller.get_urn(), self.gidObject.get_urn(), root_cred_signer.get_hrn(), root_target_gid.get_hrn()))
966 # -- For Delegates (credentials with parents) verify that:
967 # . The privileges must be a subset of the parent credentials
968 # . The privileges must have "can_delegate" set for each delegated privilege
969 # . The target gid must be the same between child and parents
970 # . The expiry time on the child must be no later than the parent
971 # . The signer of the child must be the owner of the parent
972 def verify_parent(self, parent_cred):
973 # make sure the rights given to the child are a subset of the
974 # parents rights (and check delegate bits)
975 if not parent_cred.get_privileges().is_superset(self.get_privileges()):
976 raise ChildRightsNotSubsetOfParent(("Parent cred ref %s rights " % parent_cred.get_refid()) +
977 self.parent.get_privileges().save_to_string() + (" not superset of delegated cred %s ref %s rights " % (self.get_summary_tostring(), self.get_refid())) +
978 self.get_privileges().save_to_string())
980 # make sure my target gid is the same as the parent's
981 if not parent_cred.get_gid_object().save_to_string() == \
982 self.get_gid_object().save_to_string():
983 raise CredentialNotVerifiable("Delegated cred %s: Target gid not equal between parent and child. Parent %s" % (self.get_summary_tostring(), parent_cred.get_summary_tostring()))
985 # make sure my expiry time is <= my parent's
986 if not parent_cred.get_expiration() >= self.get_expiration():
987 raise CredentialNotVerifiable("Delegated credential %s expires after parent %s" % (self.get_summary_tostring(), parent_cred.get_summary_tostring()))
989 # make sure my signer is the parent's caller
990 if not parent_cred.get_gid_caller().save_to_string(False) == \
991 self.get_signature().get_issuer_gid().save_to_string(False):
992 raise CredentialNotVerifiable("Delegated credential %s not signed by parent %s's caller" % (self.get_summary_tostring(), parent_cred.get_summary_tostring()))
995 if parent_cred.parent:
996 parent_cred.verify_parent(parent_cred.parent)
999 def delegate(self, delegee_gidfile, caller_keyfile, caller_gidfile):
1001 Return a delegated copy of this credential, delegated to the
1002 specified gid's user.
1004 # get the gid of the object we are delegating
1005 object_gid = self.get_gid_object()
1006 object_hrn = object_gid.get_hrn()
1008 # the hrn of the user who will be delegated to
1009 delegee_gid = GID(filename=delegee_gidfile)
1010 delegee_hrn = delegee_gid.get_hrn()
1012 #user_key = Keypair(filename=keyfile)
1013 #user_hrn = self.get_gid_caller().get_hrn()
1014 subject_string = "%s delegated to %s" % (object_hrn, delegee_hrn)
1015 dcred = Credential(subject=subject_string)
1016 dcred.set_gid_caller(delegee_gid)
1017 dcred.set_gid_object(object_gid)
1018 dcred.set_parent(self)
1019 dcred.set_expiration(self.get_expiration())
1020 dcred.set_privileges(self.get_privileges())
1021 dcred.get_privileges().delegate_all_privileges(True)
1022 #dcred.set_issuer_keys(keyfile, delegee_gidfile)
1023 dcred.set_issuer_keys(caller_keyfile, caller_gidfile)
1030 def get_filename(self):
1031 return getattr(self,'filename',None)
1034 # Dump the contents of a credential to stdout in human-readable format
1036 # @param dump_parents If true, also dump the parent certificates
1037 def dump (self, *args, **kwargs):
1038 print self.dump_string(*args, **kwargs)
1041 def dump_string(self, dump_parents=False):
1043 result += "CREDENTIAL %s\n" % self.get_subject()
1044 filename=self.get_filename()
1045 if filename: result += "Filename %s\n"%filename
1046 result += " privs: %s\n" % self.get_privileges().save_to_string()
1047 gidCaller = self.get_gid_caller()
1049 result += " gidCaller:\n"
1050 result += gidCaller.dump_string(8, dump_parents)
1052 if self.get_signature():
1054 self.get_signature().get_issuer_gid().dump(8, dump_parents)
1056 gidObject = self.get_gid_object()
1058 result += " gidObject:\n"
1059 result += gidObject.dump_string(8, dump_parents)
1061 if self.parent and dump_parents:
1062 result += "\nPARENT"
1063 result += self.parent.dump_string(True)