X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=sfa%2Ftrust%2Fcredential.py;h=ad2d201ae36418afa063f5ba263fdbcc5e70c85c;hb=3d51e29695f79b143974f5cf7b2e104d89626ba4;hp=45c34f81c8e2d7d5fc693e8943904e7d0e9a58bc;hpb=1c663cf3a4a011d01a8dec6ec1b98834b23c00f0;p=sfa.git diff --git a/sfa/trust/credential.py b/sfa/trust/credential.py index 45c34f81..ad2d201a 100644 --- a/sfa/trust/credential.py +++ b/sfa/trust/credential.py @@ -26,25 +26,32 @@ # Credentials are signed XML files that assign a subject gid privileges to an object gid ## -import os +import os,sys from types import StringTypes import datetime from StringIO import StringIO from tempfile import mkstemp from xml.dom.minidom import Document, parseString -from lxml import etree -from sfa.util.faults import * +HAVELXML = False +try: + from lxml import etree + HAVELXML = True +except: + pass + +from xml.parsers.expat import ExpatError + +from sfa.util.faults import CredentialNotVerifiable, ChildRightsNotSubsetOfParent from sfa.util.sfalogging import logger from sfa.util.sfatime import utcparse -from sfa.trust.certificate import Keypair from sfa.trust.credential_legacy import CredentialLegacy -from sfa.trust.rights import Right, Rights +from sfa.trust.rights import Right, Rights, determine_rights from sfa.trust.gid import GID -from sfa.util.xrn import urn_to_hrn +from sfa.util.xrn import urn_to_hrn, hrn_authfor_hrn # 2 weeks, in seconds -DEFAULT_CREDENTIAL_LIFETIME = 86400 * 14 +DEFAULT_CREDENTIAL_LIFETIME = 86400 * 31 # TODO: @@ -153,8 +160,10 @@ class Signature(object): def get_refid(self): + #print>>sys.stderr," \r\n \r\n credential.py Signature get_refid\ self.refid %s " %(self.refid) if not self.refid: self.decode() + #print>>sys.stderr," \r\n \r\n credential.py Signature get_refid self.refid %s " %(self.refid) return self.refid def get_xml(self): @@ -174,7 +183,11 @@ class Signature(object): self.gid = gid def decode(self): - doc = parseString(self.xml) + try: + doc = parseString(self.xml) + except ExpatError,e: + logger.log_exc ("Failed to parse credential, %s"%self.xml) + raise sig = doc.getElementsByTagName("Signature")[0] self.set_refid(sig.getAttribute("xml:id").strip("Sig_")) keyinfo = sig.getElementsByTagName("X509Data")[0] @@ -199,17 +212,19 @@ class Signature(object): # not be changed else the signature is no longer valid. So, once # you have loaded an existing signed credential, do not call encode() or sign() on it. -def filter_creds_by_caller(creds, caller_hrn): +def filter_creds_by_caller(creds, caller_hrn_list): """ Returns a list of creds who's gid caller matches the specified caller hrn """ if not isinstance(creds, list): creds = [creds] + if not isinstance(caller_hrn_list, list): + caller_hrn_list = [caller_hrn_list] caller_creds = [] for cred in creds: try: tmp_cred = Credential(string=cred) - if tmp_cred.get_gid_caller().get_hrn() == caller_hrn: + if tmp_cred.get_gid_caller().get_hrn() in caller_hrn_list: caller_creds.append(cred) except: pass return caller_creds @@ -263,7 +278,17 @@ class Credential(object): def get_subject(self): if not self.gidObject: self.decode() - return self.gidObject.get_subject() + return self.gidObject.get_printable_subject() + + # sounds like this should be __repr__ instead ?? + def get_summary_tostring(self): + if not self.gidObject: + self.decode() + obj = self.gidObject.get_printable_subject() + caller = self.gidCaller.get_printable_subject() + exp = self.get_expiration() + # Summarize the rights too? The issuer? + return "[ Grant %s rights on %s until %s ]" % (caller, obj, exp) def get_signature(self): if not self.signature: @@ -348,7 +373,7 @@ class Credential(object): # Expiration: an absolute UTC time of expiration (as either an int or string or datetime) # def set_expiration(self, expiration): - if isinstance(expiration, int): + if isinstance(expiration, (int, float)): self.expiration = datetime.datetime.fromtimestamp(expiration) elif isinstance (expiration, datetime.datetime): self.expiration = expiration @@ -357,9 +382,10 @@ class Credential(object): else: logger.error ("unexpected input type in Credential.set_expiration") + ## # get the lifetime of the credential (always in datetime format) - # + def get_expiration(self): if not self.expiration: self.decode() @@ -419,12 +445,18 @@ class Credential(object): doc = Document() signed_cred = doc.createElement("signed-credential") -# PG adds these. It would be nice to be consistent. -# But it's kind of odd for PL to use PG schemas that talk -# about tickets, and the PG CM policies. -# Note the careful addition of attributes from the parent below... -# signed_cred.setAttribute("xmlns:xsi", "http://www.w3.org/2001/XMLSchema-instance") -# signed_cred.setAttribute("xsinoNamespaceSchemaLocation", "http://www.protogeni.net/resources/credential/credential.xsd") +# Declare namespaces +# Note that credential/policy.xsd are really the PG schemas +# in a PL namespace. +# Note that delegation of credentials between the 2 only really works +# cause those schemas are identical. +# Also note these PG schemas talk about PG tickets and CM policies. + signed_cred.setAttribute("xmlns:xsi", "http://www.w3.org/2001/XMLSchema-instance") + signed_cred.setAttribute("xsi:noNamespaceSchemaLocation", "http://www.planet-lab.org/resources/sfa/credential.xsd") + 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") + +# PG says for those last 2: +# signed_cred.setAttribute("xsi:noNamespaceSchemaLocation", "http://www.protogeni.net/resources/credential/credential.xsd") # 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") doc.appendChild(signed_cred) @@ -461,13 +493,34 @@ class Credential(object): # If the root node is a signed-credential (it should be), then # get all its attributes and attach those to our signed_cred # node. - # Specifically, PG adds attributes for namespaces (which is reasonable), + # Specifically, PG and PLadd attributes for namespaces (which is reasonable), # and we need to include those again here or else their signature # no longer matches on the credential. # We expect three of these, but here we copy them all: # signed_cred.setAttribute("xmlns:xsi", "http://www.w3.org/2001/XMLSchema-instance") -# signed_cred.setAttribute("xsinoNamespaceSchemaLocation", "http://www.protogeni.net/resources/credential/credential.xsd") +# and from PG (PL is equivalent, as shown above): +# signed_cred.setAttribute("xsi:noNamespaceSchemaLocation", "http://www.protogeni.net/resources/credential/credential.xsd") # 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") + + # HOWEVER! + # PL now also declares these, with different URLs, so + # the code notices those attributes already existed with + # different values, and complains. + # This happens regularly on delegation now that PG and + # PL both declare the namespace with different URLs. + # If the content ever differs this is a problem, + # but for now it works - different URLs (values in the attributes) + # but the same actual schema, so using the PG schema + # on delegated-to-PL credentials works fine. + + # Note: you could also not copy attributes + # which already exist. It appears that both PG and PL + # will actually validate a slicecred with a parent + # signed using PG namespaces and a child signed with PL + # namespaces over the whole thing. But I don't know + # if that is a bug in xmlsec1, an accident since + # the contents of the schemas are the same, + # or something else, but it seems odd. And this works. parentRoot = sdoc.documentElement if parentRoot.tagName == "signed-credential" and parentRoot.hasAttributes(): for attrIx in range(0, parentRoot.attributes.length): @@ -477,9 +530,9 @@ class Credential(object): # Below throws InUse exception if we forgot to clone the attribute first oldAttr = signed_cred.setAttributeNode(attr.cloneNode(True)) if oldAttr and oldAttr.value != attr.value: - 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) - logger.error(msg) - raise CredentialNotVerifiable("Can't encode new valid delegated credential: %s" % msg) + 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) + logger.warn(msg) + #raise CredentialNotVerifiable("Can't encode new valid delegated credential: %s" % msg) p_cred = doc.importNode(sdoc.getElementsByTagName("credential")[0], True) p = doc.createElement("parent") @@ -538,18 +591,23 @@ class Credential(object): def updateRefID(self): if not self.parent: - self.set_refid('ref0') + self.set_refid('ref0') + #print>>sys.stderr, " \r\n \r\n updateRefID next_cred ref0 " return [] refs = [] next_cred = self.parent + while next_cred: + refs.append(next_cred.get_refid()) if next_cred.parent: next_cred = next_cred.parent + #print>>sys.stderr, " \r\n \r\n updateRefID next_cred " else: next_cred = None + #print>>sys.stderr, " \r\n \r\n updateRefID next_cred NONE" # Find a unique refid for this credential @@ -638,13 +696,19 @@ class Credential(object): # Is this a signed-cred or just a cred? if len(signed_cred) > 0: - cred = signed_cred[0].getElementsByTagName("credential")[0] + creds = signed_cred[0].getElementsByTagName("credential") signatures = signed_cred[0].getElementsByTagName("signatures") if len(signatures) > 0: sigs = signatures[0].getElementsByTagName("Signature") else: - cred = doc.getElementsByTagName("credential")[0] + creds = doc.getElementsByTagName("credential") + if creds is None or len(creds) == 0: + # malformed cred file + raise CredentialNotVerifiable("Malformed XML: No credential tag found") + + # Just take the first cred if there are more than one + cred = creds[0] self.set_refid(cred.getAttribute("xml:id")) self.set_expiration(utcparse(getTextNode(cred, "expires"))) @@ -662,7 +726,7 @@ class Credential(object): # Convert * into the default privileges for the credential's type # Each inherits the delegatability from the * above _ , type = urn_to_hrn(self.gidObject.get_urn()) - rl = rlist.determine_rights(type, self.gidObject.get_urn()) + rl = determine_rights(type, self.gidObject.get_urn()) for r in rl.rights: r.delegate = deleg rlist.add(r) @@ -704,6 +768,7 @@ class Credential(object): # . That the issuer of the credential is the authority in the target's urn # . In the case of a delegated credential, this must be true of the root # . That all of the gids presented in the credential are valid + # . Including verifying GID chains, and includ the issuer # . The credential is not expired # # -- For Delegates (credentials with parents) @@ -723,15 +788,15 @@ class Credential(object): self.decode() # validate against RelaxNG schema - if not self.legacy: + if HAVELXML and not self.legacy: if schema and os.path.exists(schema): tree = etree.parse(StringIO(self.xml)) schema_doc = etree.parse(schema) xmlschema = etree.XMLSchema(schema_doc) if not xmlschema.validate(tree): error = xmlschema.error_log.last_error - message = "%s (line %s)" % (error.message, error.line) - raise CredentialNotVerifiable(message) + message = "%s: %s (line %s)" % (self.get_summary_tostring(), error.message, error.line) + raise CredentialNotVerifiable(message) if trusted_certs_required and trusted_certs is None: trusted_certs = [] @@ -747,10 +812,12 @@ class Credential(object): # Failures here include unreadable files # or non PEM files trusted_cert_objects.append(GID(filename=f)) + #print>>sys.stderr, " \r\n \t\t\t credential.py verify trusted_certs %s" %(GID(filename=f).get_hrn()) ok_trusted_certs.append(f) except Exception, exc: logger.error("Failed to load trusted cert from %s: %r", f, exc) trusted_certs = ok_trusted_certs + #print>>sys.stderr, " \r\n \t\t\t credential.py verify trusted_certs elemnebts %s" %(len(trusted_certs)) # Use legacy verification if this is a legacy credential if self.legacy: @@ -763,7 +830,7 @@ class Credential(object): # make sure it is not expired if self.get_expiration() < datetime.datetime.utcnow(): - raise CredentialNotVerifiable("Credential expired at %s" % self.expiration.isoformat()) + raise CredentialNotVerifiable("Credential %s expired at %s" % (self.get_summary_tostring(), self.expiration.isoformat())) # Verify the signatures filename = self.save_to_random_tmp_file() @@ -771,12 +838,13 @@ class Credential(object): cert_args = " ".join(['--trusted-pem %s' % x for x in trusted_certs]) # If caller explicitly passed in None that means skip cert chain validation. - # Strange and not typical + # - Strange and not typical if trusted_certs is not None: # Verify the gids of this cred and of its parents for cur_cred in self.get_credential_list(): cur_cred.get_gid_object().verify_chain(trusted_cert_objects) - cur_cred.get_gid_caller().verify_chain(trusted_cert_objects) + cur_cred.get_gid_caller().verify_chain(trusted_cert_objects) + #print>>sys.stderr, " \r\n \t\t\t credential.py verify cur_cred get_gid_object hrn %s get_gid_caller %s" %(cur_cred.get_gid_object().get_hrn(),cur_cred.get_gid_caller().get_hrn()) refs = [] refs.append("Sig_%s" % self.get_refid()) @@ -784,7 +852,7 @@ class Credential(object): parentRefs = self.updateRefID() for ref in parentRefs: refs.append("Sig_%s" % ref) - + #print>>sys.stderr, " \r\n \t\t\t credential.py verify trusted_certs refs", ref for ref in refs: # If caller explicitly passed in None that means skip xmlsec1 validation. # Strange and not typical @@ -795,6 +863,7 @@ class Credential(object): # (self.xmlsec_path, ref, cert_args, filename) verified = os.popen('%s --verify --node-id "%s" %s %s 2>&1' \ % (self.xmlsec_path, ref, cert_args, filename)).read() + #print>>sys.stderr, " \r\n \t\t\t credential.py verify filename %s verified %s " %(filename,verified) if not verified.strip().startswith("OK"): # xmlsec errors have a msg= which is the interesting bit. mstart = verified.find("msg=") @@ -803,15 +872,17 @@ class Credential(object): mstart = mstart + 4 mend = verified.find('\\', mstart) msg = verified[mstart:mend] - raise CredentialNotVerifiable("xmlsec1 error verifying cred using Signature ID %s: %s %s" % (ref, msg, verified.strip())) + raise CredentialNotVerifiable("xmlsec1 error verifying cred %s using Signature ID %s: %s %s" % (self.get_summary_tostring(), ref, msg, verified.strip())) os.remove(filename) - + + #print>>sys.stderr, " \r\n \t\t\t credential.py HUMMM parents %s", self.parent # Verify the parents (delegation) if self.parent: self.verify_parent(self.parent) - - # Make sure the issuer is the target's authority - self.verify_issuer() + #print>>sys.stderr, " \r\n \t\t\t credential.py verify trusted_certs parents" + # Make sure the issuer is the target's authority, and is + # itself a valid GID + self.verify_issuer(trusted_cert_objects) return True ## @@ -829,31 +900,67 @@ class Credential(object): return list ## - # Make sure the credential's target gid was signed by (or is the same) the entity that signed - # the original credential or an authority over that namespace. - def verify_issuer(self): + # Make sure the credential's target gid (a) was signed by or (b) + # is the same as the entity that signed the original credential, + # or (c) is an authority over the target's namespace. + # Also ensure that the credential issuer / signer itself has a valid + # GID signature chain (signed by an authority with namespace rights). + def verify_issuer(self, trusted_gids): root_cred = self.get_credential_list()[-1] root_target_gid = root_cred.get_gid_object() root_cred_signer = root_cred.get_signature().get_issuer_gid() + # Case 1: + # Allow non authority to sign target and cred about target. + # + # Why do we need to allow non authorities to sign? + # If in the target gid validation step we correctly + # checked that the target is only signed by an authority, + # then this is just a special case of case 3. + # This short-circuit is the common case currently - + # and cause GID validation doesn't check 'authority', + # this allows users to generate valid slice credentials. if root_target_gid.is_signed_by_cert(root_cred_signer): # cred signer matches target signer, return success return - root_target_gid_str = root_target_gid.save_to_string() - root_cred_signer_str = root_cred_signer.save_to_string() - if root_target_gid_str == root_cred_signer_str: - # cred signer is target, return success - return + # Case 2: + # Allow someone to sign credential about themeselves. Used? + # If not, remove this. + #root_target_gid_str = root_target_gid.save_to_string() + #root_cred_signer_str = root_cred_signer.save_to_string() + #if root_target_gid_str == root_cred_signer_str: + # # cred signer is target, return success + # return + + # Case 3: + + # root_cred_signer is not the target_gid + # So this is a different gid that we have not verified. + # xmlsec1 verified the cert chain on this already, but + # it hasn't verified that the gid meets the HRN namespace + # requirements. + # Below we'll ensure that it is an authority. + # But we haven't verified that it is _signed by_ an authority + # We also don't know if xmlsec1 requires that cert signers + # are marked as CAs. + + # Note that if verify() gave us no trusted_gids then this + # call will fail. So skip it if we have no trusted_gids + if trusted_gids and len(trusted_gids) > 0: + root_cred_signer.verify_chain(trusted_gids) + else: + logger.debug("No trusted gids. Cannot verify that cred signer is signed by a trusted authority. Skipping that check.") - # See if it the signer is an authority over the domain of the target + # See if the signer is an authority over the domain of the target. + # There are multiple types of authority - accept them all here # Maybe should be (hrn, type) = urn_to_hrn(root_cred_signer.get_urn()) root_cred_signer_type = root_cred_signer.get_type() - if (root_cred_signer_type == 'authority'): - #sfa_logger.debug('Cred signer is an authority') + if (root_cred_signer_type.find('authority') == 0): + #logger.debug('Cred signer is an authority') # signer is an authority, see if target is in authority's domain - hrn = root_cred_signer.get_hrn() - if root_target_gid.get_hrn().startswith(hrn): + signerhrn = root_cred_signer.get_hrn() + if hrn_authfor_hrn(signerhrn, root_target_gid.get_hrn()): return # We've required that the credential be signed by an authority @@ -875,26 +982,27 @@ class Credential(object): # . The expiry time on the child must be no later than the parent # . The signer of the child must be the owner of the parent def verify_parent(self, parent_cred): + #print>>sys.stderr, " \r\n\r\n \t verify_parent parent_cred.get_gid_caller().save_to_string(False) %s self.get_signature().get_issuer_gid().save_to_string(False) %s" %(parent_cred.get_gid_caller().get_hrn(),self.get_signature().get_issuer_gid().get_hrn()) # make sure the rights given to the child are a subset of the # parents rights (and check delegate bits) if not parent_cred.get_privileges().is_superset(self.get_privileges()): - raise ChildRightsNotSubsetOfParent(("Parent cred ref %s rights " % self.parent.get_refid()) + - self.parent.get_privileges().save_to_string() + (" not superset of delegated cred ref %s rights " % self.get_refid()) + + raise ChildRightsNotSubsetOfParent(("Parent cred ref %s rights " % parent_cred.get_refid()) + + self.parent.get_privileges().save_to_string() + (" not superset of delegated cred %s ref %s rights " % (self.get_summary_tostring(), self.get_refid())) + self.get_privileges().save_to_string()) # make sure my target gid is the same as the parent's if not parent_cred.get_gid_object().save_to_string() == \ self.get_gid_object().save_to_string(): - raise CredentialNotVerifiable("Target gid not equal between parent and child") + raise CredentialNotVerifiable("Delegated cred %s: Target gid not equal between parent and child. Parent %s" % (self.get_summary_tostring(), parent_cred.get_summary_tostring())) # make sure my expiry time is <= my parent's if not parent_cred.get_expiration() >= self.get_expiration(): - raise CredentialNotVerifiable("Delegated credential expires after parent") + raise CredentialNotVerifiable("Delegated credential %s expires after parent %s" % (self.get_summary_tostring(), parent_cred.get_summary_tostring())) # make sure my signer is the parent's caller if not parent_cred.get_gid_caller().save_to_string(False) == \ self.get_signature().get_issuer_gid().save_to_string(False): - raise CredentialNotVerifiable("Delegated credential not signed by parent caller") + raise CredentialNotVerifiable("Delegated credential %s not signed by parent %s's caller" % (self.get_summary_tostring(), parent_cred.get_summary_tostring())) # Recurse if parent_cred.parent: @@ -934,7 +1042,7 @@ class Credential(object): # only informative def get_filename(self): return getattr(self,'filename',None) - + ## # Dump the contents of a credential to stdout in human-readable format # @@ -965,6 +1073,6 @@ class Credential(object): if self.parent and dump_parents: result += "\nPARENT" - result += self.parent.dump(True) + result += self.parent.dump_string(True) return result