X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=sfa%2Ftrust%2Fcredential.py;h=d9368c4a54c109579da16ac06093ce1bb26a947e;hb=1cc8e9613cab8b5b22478de369f259e591c54e6d;hp=bd7e7f1dc19a092fd455a14a5997731dc7099adc;hpb=b9e582564804f4538056758e86dee84c8fc5e6f5;p=sfa.git diff --git a/sfa/trust/credential.py b/sfa/trust/credential.py index bd7e7f1d..d9368c4a 100644 --- a/sfa/trust/credential.py +++ b/sfa/trust/credential.py @@ -32,19 +32,26 @@ 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: @@ -174,7 +181,11 @@ 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@@ -199,17 +210,19 @@ class Signature(object): # not be changed else the signature is no longer valid.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 @@ -224,7 +237,7 @@ class Credential(object): # @param string If string!=None, load the credential from the string # @param filename If filename!=None, load the credential from the file # FIXME: create and subject are ignored! - def __init__(self, create=False, subject=None, string=None, filename=None): + def __init__(self, create=False, subject=None, string=None, filename=None, cred=None): self.gidCaller = None self.gidObject = None self.expiration = None @@ -237,6 +250,19 @@ class Credential(object): self.xml = None self.refid = None self.legacy = None + self.type = None + self.version = None + + if cred: + if isinstance(cred, StringTypes): + string = cred + self.type = 'geni_sfa' + self.version = '1.0' + elif isinstance(cred, dict): + string = cred['geni_value'] + self.type = cred['geni_type'] + self.version = cred['geni_version'] + # Check if this is a legacy credential, translate it if so if string or filename: @@ -261,9 +287,22 @@ class Credential(object): break def get_subject(self): + subject = "" + if not self.gidObject: + self.decode() + if self.gidObject: + subject = self.gidObject.get_printable_subject() + return subject + + # sounds like this should be __repr__ instead ?? + def get_summary_tostring(self): if not self.gidObject: self.decode() - return self.gidObject.get_subject() + 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: @@ -341,14 +380,12 @@ class Credential(object): if not self.gidObject: self.decode() return self.gidObject - - ## # Expiration: an absolute UTC time of expiration (as either an int or string or datetime) # def set_expiration(self, expiration): - if isinstance(expiration, (int,float)): + if isinstance(expiration, (int, float)): self.expiration = datetime.datetime.fromtimestamp(expiration) elif isinstance (expiration, datetime.datetime): self.expiration = expiration @@ -357,9 +394,10 @@ 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() @@ -380,8 +418,7 @@ class Credential(object): if isinstance(privs, str): self.privileges = Rights(string = privs) else: - self.privileges = privs - + self.privileges = privs ## # return the privileges as a Rights object @@ -419,12 +456,18 @@ 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 +504,34 @@ 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 +541,9 @@ 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") @@ -632,19 +696,31 @@ class Credential(object): def decode(self): if not self.xml: return + + doc = None + try: + doc = parseString(self.xml) + except ExpatError,e: + raise CredentialNotVerifiable("Malformed credential") doc = parseString(self.xml) sigs = [] signed_cred = doc.getElementsByTagName("signed-credential") # 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 +738,7 @@ 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 +780,7 @@ 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 +800,15 @@ 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 = [] @@ -763,7 +840,7 @@ 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() @@ -771,7 +848,7 @@ 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(): @@ -803,15 +880,16 @@ 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) # Verify the parents (delegation) if self.parent: self.verify_parent(self.parent) - # Make sure the issuer is the target's authority - self.verify_issuer() + # 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 +907,67 @@ 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 @@ -878,23 +992,23 @@ class Credential(object): # 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 +1048,7 @@ 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 # @@ -948,7 +1062,11 @@ class Credential(object): result += "CREDENTIAL %s\n" % self.get_subject() filename=self.get_filename() if filename: result += "Filename %s\n"%filename - result += " privs: %s\n" % self.get_privileges().save_to_string() + privileges = self.get_privileges() + if privileges: + result += " privs: %s\n" % privileges.save_to_string() + else: + result += " privs: \n" gidCaller = self.get_gid_caller() if gidCaller: result += " gidCaller:\n" @@ -958,6 +1076,9 @@ class Credential(object): print " gidIssuer:" self.get_signature().get_issuer_gid().dump(8, dump_parents) + if self.expiration: + print " expiration:", self.expiration.isoformat() + gidObject = self.get_gid_object() if gidObject: result += " gidObject:\n" @@ -965,6 +1086,6 @@ class Credential(object): if self.parent and dump_parents: result += "\nPARENT" - result += self.parent.dump(True) + result += self.parent.dump_string(True) return result