1 #----------------------------------------------------------------------
\r
2 # Copyright (c) 2008 Board of Trustees, Princeton University
\r
4 # Permission is hereby granted, free of charge, to any person obtaining
\r
5 # a copy of this software and/or hardware specification (the "Work") to
\r
6 # deal in the Work without restriction, including without limitation the
\r
7 # rights to use, copy, modify, merge, publish, distribute, sublicense,
\r
8 # and/or sell copies of the Work, and to permit persons to whom the Work
\r
9 # is furnished to do so, subject to the following conditions:
\r
11 # The above copyright notice and this permission notice shall be
\r
12 # included in all copies or substantial portions of the Work.
\r
14 # THE WORK IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
\r
15 # OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
\r
16 # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
\r
17 # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
\r
18 # HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
\r
19 # WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
\r
20 # OUT OF OR IN CONNECTION WITH THE WORK OR THE USE OR OTHER DEALINGS
\r
22 #----------------------------------------------------------------------
\r
24 # Implements SFA Credentials
\r
26 # Credentials are signed XML files that assign a subject gid privileges to an object gid
\r
30 from types import StringTypes
\r
32 from StringIO import StringIO
\r
33 from tempfile import mkstemp
\r
34 from xml.dom.minidom import Document, parseString
\r
38 from lxml import etree
\r
43 from sfa.util.faults import *
\r
44 from sfa.util.sfalogging import logger
\r
45 from sfa.util.sfatime import utcparse
\r
46 from sfa.trust.certificate import Keypair
\r
47 from sfa.trust.credential_legacy import CredentialLegacy
\r
48 from sfa.trust.rights import Right, Rights, determine_rights
\r
49 from sfa.trust.gid import GID
\r
50 from sfa.util.xrn import urn_to_hrn, hrn_authfor_hrn
\r
52 # 2 weeks, in seconds
\r
53 DEFAULT_CREDENTIAL_LIFETIME = 86400 * 14
\r
57 # . make privs match between PG and PL
\r
58 # . Need to add support for other types of credentials, e.g. tickets
\r
59 # . add namespaces to signed-credential element?
\r
61 signature_template = \
\r
63 <Signature xml:id="Sig_%s" xmlns="http://www.w3.org/2000/09/xmldsig#">
\r
65 <CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
\r
66 <SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/>
\r
67 <Reference URI="#%s">
\r
69 <Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature" />
\r
71 <DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>
\r
72 <DigestValue></DigestValue>
\r
87 # PG formats the template (whitespace) slightly differently.
\r
88 # Note that they don't include the xmlns in the template, but add it later.
\r
89 # Otherwise the two are equivalent.
\r
90 #signature_template_as_in_pg = \
\r
92 #<Signature xml:id="Sig_%s" >
\r
94 # <CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
\r
95 # <SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/>
\r
96 # <Reference URI="#%s">
\r
98 # <Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature" />
\r
100 # <DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>
\r
101 # <DigestValue></DigestValue>
\r
104 # <SignatureValue />
\r
107 # <X509SubjectName/>
\r
108 # <X509IssuerSerial/>
\r
109 # <X509Certificate/>
\r
117 # Convert a string into a bool
\r
118 # used to convert an xsd:boolean to a Python boolean
\r
120 if str.lower() in ['true','1']:
\r
126 # Utility function to get the text of an XML element
\r
128 def getTextNode(element, subele):
\r
129 sub = element.getElementsByTagName(subele)[0]
\r
130 if len(sub.childNodes) > 0:
\r
131 return sub.childNodes[0].nodeValue
\r
136 # Utility function to set the text of an XML element
\r
137 # It creates the element, adds the text to it,
\r
138 # and then appends it to the parent.
\r
140 def append_sub(doc, parent, element, text):
\r
141 ele = doc.createElement(element)
\r
142 ele.appendChild(doc.createTextNode(text))
\r
143 parent.appendChild(ele)
\r
146 # Signature contains information about an xmlsec1 signature
\r
147 # for a signed-credential
\r
150 class Signature(object):
\r
152 def __init__(self, string=None):
\r
154 self.issuer_gid = None
\r
161 def get_refid(self):
\r
171 def set_refid(self, id):
\r
174 def get_issuer_gid(self):
\r
179 def set_issuer_gid(self, gid):
\r
184 doc = parseString(self.xml)
\r
185 except ExpatError,e:
\r
186 logger.log_exc ("Failed to parse credential, %s"%self.xml)
\r
188 sig = doc.getElementsByTagName("Signature")[0]
\r
189 self.set_refid(sig.getAttribute("xml:id").strip("Sig_"))
\r
190 keyinfo = sig.getElementsByTagName("X509Data")[0]
\r
191 szgid = getTextNode(keyinfo, "X509Certificate")
\r
192 szgid = "-----BEGIN CERTIFICATE-----\n%s\n-----END CERTIFICATE-----" % szgid
\r
193 self.set_issuer_gid(GID(string=szgid))
\r
196 self.xml = signature_template % (self.get_refid(), self.get_refid())
\r
200 # A credential provides a caller gid with privileges to an object gid.
\r
201 # A signed credential is signed by the object's authority.
\r
203 # Credentials are encoded in one of two ways. The legacy style places
\r
204 # it in the subjectAltName of an X509 certificate. The new credentials
\r
205 # are placed in signed XML.
\r
208 # In general, a signed credential obtained externally should
\r
209 # not be changed else the signature is no longer valid. So, once
\r
210 # you have loaded an existing signed credential, do not call encode() or sign() on it.
\r
212 def filter_creds_by_caller(creds, caller_hrn):
\r
214 Returns a list of creds who's gid caller matches the
\r
215 specified caller hrn
\r
217 if not isinstance(creds, list): creds = [creds]
\r
221 tmp_cred = Credential(string=cred)
\r
222 if tmp_cred.get_gid_caller().get_hrn() == caller_hrn:
\r
223 caller_creds.append(cred)
\r
225 return caller_creds
\r
227 class Credential(object):
\r
230 # Create a Credential object
\r
232 # @param create If true, create a blank x509 certificate
\r
233 # @param subject If subject!=None, create an x509 cert with the subject name
\r
234 # @param string If string!=None, load the credential from the string
\r
235 # @param filename If filename!=None, load the credential from the file
\r
236 # FIXME: create and subject are ignored!
\r
237 def __init__(self, create=False, subject=None, string=None, filename=None):
\r
238 self.gidCaller = None
\r
239 self.gidObject = None
\r
240 self.expiration = None
\r
241 self.privileges = None
\r
242 self.issuer_privkey = None
\r
243 self.issuer_gid = None
\r
244 self.issuer_pubkey = None
\r
246 self.signature = None
\r
251 # Check if this is a legacy credential, translate it if so
\r
252 if string or filename:
\r
256 str = file(filename).read()
\r
258 if str.strip().startswith("-----"):
\r
259 self.legacy = CredentialLegacy(False,string=str)
\r
260 self.translate_legacy(str)
\r
265 # Find an xmlsec1 path
\r
266 self.xmlsec_path = ''
\r
267 paths = ['/usr/bin','/usr/local/bin','/bin','/opt/bin','/opt/local/bin']
\r
269 if os.path.isfile(path + '/' + 'xmlsec1'):
\r
270 self.xmlsec_path = path + '/' + 'xmlsec1'
\r
273 def get_subject(self):
\r
274 if not self.gidObject:
\r
276 return self.gidObject.get_printable_subject()
\r
278 def get_summary_tostring(self):
\r
279 if not self.gidObject:
\r
281 obj = self.gidObject.get_printable_subject()
\r
282 caller = self.gidCaller.get_printable_subject()
\r
283 exp = self.get_expiration()
\r
284 # Summarize the rights too? The issuer?
\r
285 return "[ Grant %s rights on %s until %s ]" % (caller, obj, exp)
\r
287 def get_signature(self):
\r
288 if not self.signature:
\r
290 return self.signature
\r
292 def set_signature(self, sig):
\r
293 self.signature = sig
\r
297 # Translate a legacy credential into a new one
\r
299 # @param String of the legacy credential
\r
301 def translate_legacy(self, str):
\r
302 legacy = CredentialLegacy(False,string=str)
\r
303 self.gidCaller = legacy.get_gid_caller()
\r
304 self.gidObject = legacy.get_gid_object()
\r
305 lifetime = legacy.get_lifetime()
\r
307 self.set_expiration(datetime.datetime.utcnow() + datetime.timedelta(seconds=DEFAULT_CREDENTIAL_LIFETIME))
\r
309 self.set_expiration(int(lifetime))
\r
310 self.lifeTime = legacy.get_lifetime()
\r
311 self.set_privileges(legacy.get_privileges())
\r
312 self.get_privileges().delegate_all_privileges(legacy.get_delegate())
\r
315 # Need the issuer's private key and name
\r
316 # @param key Keypair object containing the private key of the issuer
\r
317 # @param gid GID of the issuing authority
\r
319 def set_issuer_keys(self, privkey, gid):
\r
320 self.issuer_privkey = privkey
\r
321 self.issuer_gid = gid
\r
325 # Set this credential's parent
\r
326 def set_parent(self, cred):
\r
331 # set the GID of the caller
\r
333 # @param gid GID object of the caller
\r
335 def set_gid_caller(self, gid):
\r
336 self.gidCaller = gid
\r
337 # gid origin caller is the caller's gid by default
\r
338 self.gidOriginCaller = gid
\r
341 # get the GID of the object
\r
343 def get_gid_caller(self):
\r
344 if not self.gidCaller:
\r
346 return self.gidCaller
\r
349 # set the GID of the object
\r
351 # @param gid GID object of the object
\r
353 def set_gid_object(self, gid):
\r
354 self.gidObject = gid
\r
357 # get the GID of the object
\r
359 def get_gid_object(self):
\r
360 if not self.gidObject:
\r
362 return self.gidObject
\r
367 # Expiration: an absolute UTC time of expiration (as either an int or string or datetime)
\r
369 def set_expiration(self, expiration):
\r
370 if isinstance(expiration, (int, float)):
\r
371 self.expiration = datetime.datetime.fromtimestamp(expiration)
\r
372 elif isinstance (expiration, datetime.datetime):
\r
373 self.expiration = expiration
\r
374 elif isinstance (expiration, StringTypes):
\r
375 self.expiration = utcparse (expiration)
\r
377 logger.error ("unexpected input type in Credential.set_expiration")
\r
381 # get the lifetime of the credential (always in datetime format)
\r
383 def get_expiration(self):
\r
384 if not self.expiration:
\r
386 # at this point self.expiration is normalized as a datetime - DON'T call utcparse again
\r
387 return self.expiration
\r
391 def get_lifetime(self):
\r
392 return self.get_expiration()
\r
395 # set the privileges
\r
397 # @param privs either a comma-separated list of privileges of a Rights object
\r
399 def set_privileges(self, privs):
\r
400 if isinstance(privs, str):
\r
401 self.privileges = Rights(string = privs)
\r
403 self.privileges = privs
\r
407 # return the privileges as a Rights object
\r
409 def get_privileges(self):
\r
410 if not self.privileges:
\r
412 return self.privileges
\r
415 # determine whether the credential allows a particular operation to be
\r
418 # @param op_name string specifying name of operation ("lookup", "update", etc)
\r
420 def can_perform(self, op_name):
\r
421 rights = self.get_privileges()
\r
426 return rights.can_perform(op_name)
\r
430 # Encode the attributes of the credential into an XML string
\r
431 # This should be done immediately before signing the credential.
\r
433 # In general, a signed credential obtained externally should
\r
434 # not be changed else the signature is no longer valid. So, once
\r
435 # you have loaded an existing signed credential, do not call encode() or sign() on it.
\r
438 # Create the XML document
\r
440 signed_cred = doc.createElement("signed-credential")
\r
442 # Declare namespaces
\r
443 # Note that credential/policy.xsd are really the PG schemas
\r
444 # in a PL namespace.
\r
445 # Note that delegation of credentials between the 2 only really works
\r
446 # cause those schemas are identical.
\r
447 # Also note these PG schemas talk about PG tickets and CM policies.
\r
448 signed_cred.setAttribute("xmlns:xsi", "http://www.w3.org/2001/XMLSchema-instance")
\r
449 signed_cred.setAttribute("xsi:noNamespaceSchemaLocation", "http://www.planet-lab.org/resources/sfa/credential.xsd")
\r
450 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")
\r
452 # PG says for those last 2:
\r
453 # signed_cred.setAttribute("xsi:noNamespaceSchemaLocation", "http://www.protogeni.net/resources/credential/credential.xsd")
\r
454 # 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")
\r
456 doc.appendChild(signed_cred)
\r
458 # Fill in the <credential> bit
\r
459 cred = doc.createElement("credential")
\r
460 cred.setAttribute("xml:id", self.get_refid())
\r
461 signed_cred.appendChild(cred)
\r
462 append_sub(doc, cred, "type", "privilege")
\r
463 append_sub(doc, cred, "serial", "8")
\r
464 append_sub(doc, cred, "owner_gid", self.gidCaller.save_to_string())
\r
465 append_sub(doc, cred, "owner_urn", self.gidCaller.get_urn())
\r
466 append_sub(doc, cred, "target_gid", self.gidObject.save_to_string())
\r
467 append_sub(doc, cred, "target_urn", self.gidObject.get_urn())
\r
468 append_sub(doc, cred, "uuid", "")
\r
469 if not self.expiration:
\r
470 self.set_expiration(datetime.datetime.utcnow() + datetime.timedelta(seconds=DEFAULT_CREDENTIAL_LIFETIME))
\r
471 self.expiration = self.expiration.replace(microsecond=0)
\r
472 append_sub(doc, cred, "expires", self.expiration.isoformat())
\r
473 privileges = doc.createElement("privileges")
\r
474 cred.appendChild(privileges)
\r
476 if self.privileges:
\r
477 rights = self.get_privileges()
\r
478 for right in rights.rights:
\r
479 priv = doc.createElement("privilege")
\r
480 append_sub(doc, priv, "name", right.kind)
\r
481 append_sub(doc, priv, "can_delegate", str(right.delegate).lower())
\r
482 privileges.appendChild(priv)
\r
484 # Add the parent credential if it exists
\r
486 sdoc = parseString(self.parent.get_xml())
\r
487 # If the root node is a signed-credential (it should be), then
\r
488 # get all its attributes and attach those to our signed_cred
\r
490 # Specifically, PG and PLadd attributes for namespaces (which is reasonable),
\r
491 # and we need to include those again here or else their signature
\r
492 # no longer matches on the credential.
\r
493 # We expect three of these, but here we copy them all:
\r
494 # signed_cred.setAttribute("xmlns:xsi", "http://www.w3.org/2001/XMLSchema-instance")
\r
495 # and from PG (PL is equivalent, as shown above):
\r
496 # signed_cred.setAttribute("xsi:noNamespaceSchemaLocation", "http://www.protogeni.net/resources/credential/credential.xsd")
\r
497 # 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")
\r
500 # PL now also declares these, with different URLs, so
\r
501 # the code notices those attributes already existed with
\r
502 # different values, and complains.
\r
503 # This happens regularly on delegation now that PG and
\r
504 # PL both declare the namespace with different URLs.
\r
505 # If the content ever differs this is a problem,
\r
506 # but for now it works - different URLs (values in the attributes)
\r
507 # but the same actual schema, so using the PG schema
\r
508 # on delegated-to-PL credentials works fine.
\r
510 # Note: you could also not copy attributes
\r
511 # which already exist. It appears that both PG and PL
\r
512 # will actually validate a slicecred with a parent
\r
513 # signed using PG namespaces and a child signed with PL
\r
514 # namespaces over the whole thing. But I don't know
\r
515 # if that is a bug in xmlsec1, an accident since
\r
516 # the contents of the schemas are the same,
\r
517 # or something else, but it seems odd. And this works.
\r
518 parentRoot = sdoc.documentElement
\r
519 if parentRoot.tagName == "signed-credential" and parentRoot.hasAttributes():
\r
520 for attrIx in range(0, parentRoot.attributes.length):
\r
521 attr = parentRoot.attributes.item(attrIx)
\r
522 # returns the old attribute of same name that was
\r
523 # on the credential
\r
524 # Below throws InUse exception if we forgot to clone the attribute first
\r
525 oldAttr = signed_cred.setAttributeNode(attr.cloneNode(True))
\r
526 if oldAttr and oldAttr.value != attr.value:
\r
527 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)
\r
529 #raise CredentialNotVerifiable("Can't encode new valid delegated credential: %s" % msg)
\r
531 p_cred = doc.importNode(sdoc.getElementsByTagName("credential")[0], True)
\r
532 p = doc.createElement("parent")
\r
533 p.appendChild(p_cred)
\r
534 cred.appendChild(p)
\r
535 # done handling parent credential
\r
537 # Create the <signatures> tag
\r
538 signatures = doc.createElement("signatures")
\r
539 signed_cred.appendChild(signatures)
\r
541 # Add any parent signatures
\r
543 for cur_cred in self.get_credential_list()[1:]:
\r
544 sdoc = parseString(cur_cred.get_signature().get_xml())
\r
545 ele = doc.importNode(sdoc.getElementsByTagName("Signature")[0], True)
\r
546 signatures.appendChild(ele)
\r
548 # Get the finished product
\r
549 self.xml = doc.toxml()
\r
552 def save_to_random_tmp_file(self):
\r
553 fp, filename = mkstemp(suffix='cred', text=True)
\r
554 fp = os.fdopen(fp, "w")
\r
555 self.save_to_file(filename, save_parents=True, filep=fp)
\r
558 def save_to_file(self, filename, save_parents=True, filep=None):
\r
564 f = open(filename, "w")
\r
568 def save_to_string(self, save_parents=True):
\r
573 def get_refid(self):
\r
575 self.refid = 'ref0'
\r
578 def set_refid(self, rid):
\r
582 # Figure out what refids exist, and update this credential's id
\r
583 # so that it doesn't clobber the others. Returns the refids of
\r
586 def updateRefID(self):
\r
587 if not self.parent:
\r
588 self.set_refid('ref0')
\r
593 next_cred = self.parent
\r
595 refs.append(next_cred.get_refid())
\r
596 if next_cred.parent:
\r
597 next_cred = next_cred.parent
\r
602 # Find a unique refid for this credential
\r
603 rid = self.get_refid()
\r
606 rid = "ref%d" % (val + 1)
\r
608 # Set the new refid
\r
609 self.set_refid(rid)
\r
611 # Return the set of parent credential ref ids
\r
620 # Sign the XML file created by encode()
\r
623 # In general, a signed credential obtained externally should
\r
624 # not be changed else the signature is no longer valid. So, once
\r
625 # you have loaded an existing signed credential, do not call encode() or sign() on it.
\r
628 if not self.issuer_privkey or not self.issuer_gid:
\r
630 doc = parseString(self.get_xml())
\r
631 sigs = doc.getElementsByTagName("signatures")[0]
\r
633 # Create the signature template to be signed
\r
634 signature = Signature()
\r
635 signature.set_refid(self.get_refid())
\r
636 sdoc = parseString(signature.get_xml())
\r
637 sig_ele = doc.importNode(sdoc.getElementsByTagName("Signature")[0], True)
\r
638 sigs.appendChild(sig_ele)
\r
640 self.xml = doc.toxml()
\r
643 # Split the issuer GID into multiple certificates if it's a chain
\r
644 chain = GID(filename=self.issuer_gid)
\r
647 gid_files.append(chain.save_to_random_tmp_file(False))
\r
648 if chain.get_parent():
\r
649 chain = chain.get_parent()
\r
654 # Call out to xmlsec1 to sign it
\r
655 ref = 'Sig_%s' % self.get_refid()
\r
656 filename = self.save_to_random_tmp_file()
\r
657 signed = os.popen('%s --sign --node-id "%s" --privkey-pem %s,%s %s' \
\r
658 % (self.xmlsec_path, ref, self.issuer_privkey, ",".join(gid_files), filename)).read()
\r
659 os.remove(filename)
\r
661 for gid_file in gid_files:
\r
662 os.remove(gid_file)
\r
666 # This is no longer a legacy credential
\r
670 # Update signatures
\r
675 # Retrieve the attributes of the credential from the XML.
\r
676 # This is automatically called by the various get_* methods of
\r
677 # this class and should not need to be called explicitly.
\r
682 doc = parseString(self.xml)
\r
684 signed_cred = doc.getElementsByTagName("signed-credential")
\r
686 # Is this a signed-cred or just a cred?
\r
687 if len(signed_cred) > 0:
\r
688 creds = signed_cred[0].getElementsByTagName("credential")
\r
689 signatures = signed_cred[0].getElementsByTagName("signatures")
\r
690 if len(signatures) > 0:
\r
691 sigs = signatures[0].getElementsByTagName("Signature")
\r
693 creds = doc.getElementsByTagName("credential")
\r
695 if creds is None or len(creds) == 0:
\r
696 # malformed cred file
\r
697 raise CredentialNotVerifiable("Malformed XML: No credential tag found")
\r
699 # Just take the first cred if there are more than one
\r
702 self.set_refid(cred.getAttribute("xml:id"))
\r
703 self.set_expiration(utcparse(getTextNode(cred, "expires")))
\r
704 self.gidCaller = GID(string=getTextNode(cred, "owner_gid"))
\r
705 self.gidObject = GID(string=getTextNode(cred, "target_gid"))
\r
708 # Process privileges
\r
709 privs = cred.getElementsByTagName("privileges")[0]
\r
711 for priv in privs.getElementsByTagName("privilege"):
\r
712 kind = getTextNode(priv, "name")
\r
713 deleg = str2bool(getTextNode(priv, "can_delegate"))
\r
715 # Convert * into the default privileges for the credential's type
\r
716 # Each inherits the delegatability from the * above
\r
717 _ , type = urn_to_hrn(self.gidObject.get_urn())
\r
718 rl = determine_rights(type, self.gidObject.get_urn())
\r
719 for r in rl.rights:
\r
723 rlist.add(Right(kind.strip(), deleg))
\r
724 self.set_privileges(rlist)
\r
727 # Is there a parent?
\r
728 parent = cred.getElementsByTagName("parent")
\r
729 if len(parent) > 0:
\r
730 parent_doc = parent[0].getElementsByTagName("credential")[0]
\r
731 parent_xml = parent_doc.toxml()
\r
732 self.parent = Credential(string=parent_xml)
\r
735 # Assign the signatures to the credentials
\r
737 Sig = Signature(string=sig.toxml())
\r
739 for cur_cred in self.get_credential_list():
\r
740 if cur_cred.get_refid() == Sig.get_refid():
\r
741 cur_cred.set_signature(Sig)
\r
746 # trusted_certs: A list of trusted GID filenames (not GID objects!)
\r
747 # Chaining is not supported within the GIDs by xmlsec1.
\r
749 # trusted_certs_required: Should usually be true. Set False means an
\r
750 # empty list of trusted_certs would still let this method pass.
\r
751 # It just skips xmlsec1 verification et al. Only used by some utils
\r
754 # . All of the signatures are valid and that the issuers trace back
\r
755 # to trusted roots (performed by xmlsec1)
\r
756 # . The XML matches the credential schema
\r
757 # . That the issuer of the credential is the authority in the target's urn
\r
758 # . In the case of a delegated credential, this must be true of the root
\r
759 # . That all of the gids presented in the credential are valid
\r
760 # . Including verifying GID chains, and includ the issuer
\r
761 # . The credential is not expired
\r
763 # -- For Delegates (credentials with parents)
\r
764 # . The privileges must be a subset of the parent credentials
\r
765 # . The privileges must have "can_delegate" set for each delegated privilege
\r
766 # . The target gid must be the same between child and parents
\r
767 # . The expiry time on the child must be no later than the parent
\r
768 # . The signer of the child must be the owner of the parent
\r
770 # -- Verify does *NOT*
\r
771 # . ensure that an xmlrpc client's gid matches a credential gid, that
\r
772 # must be done elsewhere
\r
774 # @param trusted_certs: The certificates of trusted CA certificates
\r
775 def verify(self, trusted_certs=None, schema=None, trusted_certs_required=True):
\r
779 # validate against RelaxNG schema
\r
780 if HAVELXML and not self.legacy:
\r
781 if schema and os.path.exists(schema):
\r
782 tree = etree.parse(StringIO(self.xml))
\r
783 schema_doc = etree.parse(schema)
\r
784 xmlschema = etree.XMLSchema(schema_doc)
\r
785 if not xmlschema.validate(tree):
\r
786 error = xmlschema.error_log.last_error
\r
787 message = "%s: %s (line %s)" % (self.get_summary_tostring(), error.message, error.line)
\r
788 raise CredentialNotVerifiable(message)
\r
790 if trusted_certs_required and trusted_certs is None:
\r
793 # trusted_cert_objects = [GID(filename=f) for f in trusted_certs]
\r
794 trusted_cert_objects = []
\r
795 ok_trusted_certs = []
\r
796 # If caller explicitly passed in None that means skip cert chain validation.
\r
797 # Strange and not typical
\r
798 if trusted_certs is not None:
\r
799 for f in trusted_certs:
\r
801 # Failures here include unreadable files
\r
803 trusted_cert_objects.append(GID(filename=f))
\r
804 ok_trusted_certs.append(f)
\r
805 except Exception, exc:
\r
806 logger.error("Failed to load trusted cert from %s: %r", f, exc)
\r
807 trusted_certs = ok_trusted_certs
\r
809 # Use legacy verification if this is a legacy credential
\r
811 self.legacy.verify_chain(trusted_cert_objects)
\r
812 if self.legacy.client_gid:
\r
813 self.legacy.client_gid.verify_chain(trusted_cert_objects)
\r
814 if self.legacy.object_gid:
\r
815 self.legacy.object_gid.verify_chain(trusted_cert_objects)
\r
818 # make sure it is not expired
\r
819 if self.get_expiration() < datetime.datetime.utcnow():
\r
820 raise CredentialNotVerifiable("Credential %s expired at %s" % (self.get_summary_tostring(), self.expiration.isoformat()))
\r
822 # Verify the signatures
\r
823 filename = self.save_to_random_tmp_file()
\r
824 if trusted_certs is not None:
\r
825 cert_args = " ".join(['--trusted-pem %s' % x for x in trusted_certs])
\r
827 # If caller explicitly passed in None that means skip cert chain validation.
\r
828 # - Strange and not typical
\r
829 if trusted_certs is not None:
\r
830 # Verify the gids of this cred and of its parents
\r
831 for cur_cred in self.get_credential_list():
\r
832 cur_cred.get_gid_object().verify_chain(trusted_cert_objects)
\r
833 cur_cred.get_gid_caller().verify_chain(trusted_cert_objects)
\r
836 refs.append("Sig_%s" % self.get_refid())
\r
838 parentRefs = self.updateRefID()
\r
839 for ref in parentRefs:
\r
840 refs.append("Sig_%s" % ref)
\r
843 # If caller explicitly passed in None that means skip xmlsec1 validation.
\r
844 # Strange and not typical
\r
845 if trusted_certs is None:
\r
848 # print "Doing %s --verify --node-id '%s' %s %s 2>&1" % \
\r
849 # (self.xmlsec_path, ref, cert_args, filename)
\r
850 verified = os.popen('%s --verify --node-id "%s" %s %s 2>&1' \
\r
851 % (self.xmlsec_path, ref, cert_args, filename)).read()
\r
852 if not verified.strip().startswith("OK"):
\r
853 # xmlsec errors have a msg= which is the interesting bit.
\r
854 mstart = verified.find("msg=")
\r
856 if mstart > -1 and len(verified) > 4:
\r
857 mstart = mstart + 4
\r
858 mend = verified.find('\\', mstart)
\r
859 msg = verified[mstart:mend]
\r
860 raise CredentialNotVerifiable("xmlsec1 error verifying cred %s using Signature ID %s: %s %s" % (self.get_summary_tostring(), ref, msg, verified.strip()))
\r
861 os.remove(filename)
\r
863 # Verify the parents (delegation)
\r
865 self.verify_parent(self.parent)
\r
867 # Make sure the issuer is the target's authority, and is
\r
868 # itself a valid GID
\r
869 self.verify_issuer(trusted_cert_objects)
\r
873 # Creates a list of the credential and its parents, with the root
\r
874 # (original delegated credential) as the last item in the list
\r
875 def get_credential_list(self):
\r
879 list.append(cur_cred)
\r
880 if cur_cred.parent:
\r
881 cur_cred = cur_cred.parent
\r
887 # Make sure the credential's target gid (a) was signed by or (b)
\r
888 # is the same as the entity that signed the original credential,
\r
889 # or (c) is an authority over the target's namespace.
\r
890 # Also ensure that the credential issuer / signer itself has a valid
\r
891 # GID signature chain (signed by an authority with namespace rights).
\r
892 def verify_issuer(self, trusted_gids):
\r
893 root_cred = self.get_credential_list()[-1]
\r
894 root_target_gid = root_cred.get_gid_object()
\r
895 root_cred_signer = root_cred.get_signature().get_issuer_gid()
\r
898 # Allow non authority to sign target and cred about target.
\r
900 # Why do we need to allow non authorities to sign?
\r
901 # If in the target gid validation step we correctly
\r
902 # checked that the target is only signed by an authority,
\r
903 # then this is just a special case of case 3.
\r
904 # This short-circuit is the common case currently -
\r
905 # and cause GID validation doesn't check 'authority',
\r
906 # this allows users to generate valid slice credentials.
\r
907 if root_target_gid.is_signed_by_cert(root_cred_signer):
\r
908 # cred signer matches target signer, return success
\r
912 # Allow someone to sign credential about themeselves. Used?
\r
913 # If not, remove this.
\r
914 #root_target_gid_str = root_target_gid.save_to_string()
\r
915 #root_cred_signer_str = root_cred_signer.save_to_string()
\r
916 #if root_target_gid_str == root_cred_signer_str:
\r
917 # # cred signer is target, return success
\r
922 # root_cred_signer is not the target_gid
\r
923 # So this is a different gid that we have not verified.
\r
924 # xmlsec1 verified the cert chain on this already, but
\r
925 # it hasn't verified that the gid meets the HRN namespace
\r
927 # Below we'll ensure that it is an authority.
\r
928 # But we haven't verified that it is _signed by_ an authority
\r
929 # We also don't know if xmlsec1 requires that cert signers
\r
930 # are marked as CAs.
\r
932 # Note that if verify() gave us no trusted_gids then this
\r
933 # call will fail. So skip it if we have no trusted_gids
\r
934 if trusted_gids and len(trusted_gids) > 0:
\r
935 root_cred_signer.verify_chain(trusted_gids)
\r
937 logger.debug("No trusted gids. Cannot verify that cred signer is signed by a trusted authority. Skipping that check.")
\r
939 # See if the signer is an authority over the domain of the target.
\r
940 # There are multiple types of authority - accept them all here
\r
941 # Maybe should be (hrn, type) = urn_to_hrn(root_cred_signer.get_urn())
\r
942 root_cred_signer_type = root_cred_signer.get_type()
\r
943 if (root_cred_signer_type.find('authority') == 0):
\r
944 #logger.debug('Cred signer is an authority')
\r
945 # signer is an authority, see if target is in authority's domain
\r
946 signerhrn = root_cred_signer.get_hrn()
\r
947 if hrn_authfor_hrn(signerhrn, root_target_gid.get_hrn()):
\r
950 # We've required that the credential be signed by an authority
\r
951 # for that domain. Reasonable and probably correct.
\r
952 # A looser model would also allow the signer to be an authority
\r
953 # in my control framework - eg My CA or CH. Even if it is not
\r
954 # the CH that issued these, eg, user credentials.
\r
956 # Give up, credential does not pass issuer verification
\r
958 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()))
\r
962 # -- For Delegates (credentials with parents) verify that:
\r
963 # . The privileges must be a subset of the parent credentials
\r
964 # . The privileges must have "can_delegate" set for each delegated privilege
\r
965 # . The target gid must be the same between child and parents
\r
966 # . The expiry time on the child must be no later than the parent
\r
967 # . The signer of the child must be the owner of the parent
\r
968 def verify_parent(self, parent_cred):
\r
969 # make sure the rights given to the child are a subset of the
\r
970 # parents rights (and check delegate bits)
\r
971 if not parent_cred.get_privileges().is_superset(self.get_privileges()):
\r
972 raise ChildRightsNotSubsetOfParent(("Parent cred ref %s rights " % parent_cred.get_refid()) +
\r
973 self.parent.get_privileges().save_to_string() + (" not superset of delegated cred %s ref %s rights " % (self.get_summary_tostring(), self.get_refid())) +
\r
974 self.get_privileges().save_to_string())
\r
976 # make sure my target gid is the same as the parent's
\r
977 if not parent_cred.get_gid_object().save_to_string() == \
\r
978 self.get_gid_object().save_to_string():
\r
979 raise CredentialNotVerifiable("Delegated cred %s: Target gid not equal between parent and child. Parent %s" % (self.get_summary_tostring(), parent_cred.get_summary_tostring()))
\r
981 # make sure my expiry time is <= my parent's
\r
982 if not parent_cred.get_expiration() >= self.get_expiration():
\r
983 raise CredentialNotVerifiable("Delegated credential %s expires after parent %s" % (self.get_summary_tostring(), parent_cred.get_summary_tostring()))
\r
985 # make sure my signer is the parent's caller
\r
986 if not parent_cred.get_gid_caller().save_to_string(False) == \
\r
987 self.get_signature().get_issuer_gid().save_to_string(False):
\r
988 raise CredentialNotVerifiable("Delegated credential %s not signed by parent %s's caller" % (self.get_summary_tostring(), parent_cred.get_summary_tostring()))
\r
991 if parent_cred.parent:
\r
992 parent_cred.verify_parent(parent_cred.parent)
\r
995 def delegate(self, delegee_gidfile, caller_keyfile, caller_gidfile):
\r
997 Return a delegated copy of this credential, delegated to the
\r
998 specified gid's user.
\r
1000 # get the gid of the object we are delegating
\r
1001 object_gid = self.get_gid_object()
\r
1002 object_hrn = object_gid.get_hrn()
\r
1004 # the hrn of the user who will be delegated to
\r
1005 delegee_gid = GID(filename=delegee_gidfile)
\r
1006 delegee_hrn = delegee_gid.get_hrn()
\r
1008 #user_key = Keypair(filename=keyfile)
\r
1009 #user_hrn = self.get_gid_caller().get_hrn()
\r
1010 subject_string = "%s delegated to %s" % (object_hrn, delegee_hrn)
\r
1011 dcred = Credential(subject=subject_string)
\r
1012 dcred.set_gid_caller(delegee_gid)
\r
1013 dcred.set_gid_object(object_gid)
\r
1014 dcred.set_parent(self)
\r
1015 dcred.set_expiration(self.get_expiration())
\r
1016 dcred.set_privileges(self.get_privileges())
\r
1017 dcred.get_privileges().delegate_all_privileges(True)
\r
1018 #dcred.set_issuer_keys(keyfile, delegee_gidfile)
\r
1019 dcred.set_issuer_keys(caller_keyfile, caller_gidfile)
\r
1025 # only informative
\r
1026 def get_filename(self):
\r
1027 return getattr(self,'filename',None)
\r
1030 # Dump the contents of a credential to stdout in human-readable format
\r
1032 # @param dump_parents If true, also dump the parent certificates
\r
1033 def dump (self, *args, **kwargs):
\r
1034 print self.dump_string(*args, **kwargs)
\r
1037 def dump_string(self, dump_parents=False):
\r
1039 result += "CREDENTIAL %s\n" % self.get_subject()
\r
1040 filename=self.get_filename()
\r
1041 if filename: result += "Filename %s\n"%filename
\r
1042 result += " privs: %s\n" % self.get_privileges().save_to_string()
\r
1043 gidCaller = self.get_gid_caller()
\r
1045 result += " gidCaller:\n"
\r
1046 result += gidCaller.dump_string(8, dump_parents)
\r
1048 if self.get_signature():
\r
1049 print " gidIssuer:"
\r
1050 self.get_signature().get_issuer_gid().dump(8, dump_parents)
\r
1052 gidObject = self.get_gid_object()
\r
1054 result += " gidObject:\n"
\r
1055 result += gidObject.dump_string(8, dump_parents)
\r
1057 if self.parent and dump_parents:
\r
1058 result += "\nPARENT"
\r
1059 result += self.parent.dump_string(True)
\r