-#----------------------------------------------------------------------\r
-# Copyright (c) 2008 Board of Trustees, Princeton University\r
-#\r
-# Permission is hereby granted, free of charge, to any person obtaining\r
-# a copy of this software and/or hardware specification (the "Work") to\r
-# deal in the Work without restriction, including without limitation the\r
-# rights to use, copy, modify, merge, publish, distribute, sublicense,\r
-# and/or sell copies of the Work, and to permit persons to whom the Work\r
-# is furnished to do so, subject to the following conditions:\r
-#\r
-# The above copyright notice and this permission notice shall be\r
-# included in all copies or substantial portions of the Work.\r
-#\r
-# THE WORK IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS \r
-# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF \r
-# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND \r
-# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT \r
-# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, \r
-# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, \r
-# OUT OF OR IN CONNECTION WITH THE WORK OR THE USE OR OTHER DEALINGS \r
-# IN THE WORK.\r
-#----------------------------------------------------------------------\r
-##\r
-# Implements SFA Credentials\r
-#\r
-# Credentials are signed XML files that assign a subject gid privileges to an object gid\r
-##\r
-\r
-import os\r
-from types import StringTypes\r
-import datetime\r
-from StringIO import StringIO\r
-from tempfile import mkstemp\r
-from xml.dom.minidom import Document, parseString\r
-\r
-HAVELXML = False\r
-try:\r
- from lxml import etree\r
- HAVELXML = True\r
-except:\r
- pass\r
-\r
-from xml.parsers.expat import ExpatError\r
-\r
-from sfa.util.faults import CredentialNotVerifiable, ChildRightsNotSubsetOfParent\r
-from sfa.util.sfalogging import logger\r
-from sfa.util.sfatime import utcparse\r
-from sfa.trust.credential_legacy import CredentialLegacy\r
-from sfa.trust.rights import Right, Rights, determine_rights\r
-from sfa.trust.gid import GID\r
-from sfa.util.xrn import urn_to_hrn, hrn_authfor_hrn\r
-\r
-# 2 weeks, in seconds \r
-DEFAULT_CREDENTIAL_LIFETIME = 86400 * 31\r
-\r
-\r
-# TODO:\r
-# . make privs match between PG and PL\r
-# . Need to add support for other types of credentials, e.g. tickets\r
-# . add namespaces to signed-credential element?\r
-\r
-signature_template = \\r
-'''\r
-<Signature xml:id="Sig_%s" xmlns="http://www.w3.org/2000/09/xmldsig#">\r
- <SignedInfo>\r
- <CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>\r
- <SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/>\r
- <Reference URI="#%s">\r
- <Transforms>\r
- <Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature" />\r
- </Transforms>\r
- <DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>\r
- <DigestValue></DigestValue>\r
- </Reference>\r
- </SignedInfo>\r
- <SignatureValue />\r
- <KeyInfo>\r
- <X509Data>\r
- <X509SubjectName/>\r
- <X509IssuerSerial/>\r
- <X509Certificate/>\r
- </X509Data>\r
- <KeyValue />\r
- </KeyInfo>\r
-</Signature>\r
-'''\r
-\r
-# PG formats the template (whitespace) slightly differently.\r
-# Note that they don't include the xmlns in the template, but add it later.\r
-# Otherwise the two are equivalent.\r
-#signature_template_as_in_pg = \\r
-#'''\r
-#<Signature xml:id="Sig_%s" >\r
-# <SignedInfo>\r
-# <CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>\r
-# <SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/>\r
-# <Reference URI="#%s">\r
-# <Transforms>\r
-# <Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature" />\r
-# </Transforms>\r
-# <DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>\r
-# <DigestValue></DigestValue>\r
-# </Reference>\r
-# </SignedInfo>\r
-# <SignatureValue />\r
-# <KeyInfo>\r
-# <X509Data >\r
-# <X509SubjectName/>\r
-# <X509IssuerSerial/>\r
-# <X509Certificate/>\r
-# </X509Data>\r
-# <KeyValue />\r
-# </KeyInfo>\r
-#</Signature>\r
-#'''\r
-\r
-##\r
-# Convert a string into a bool\r
-# used to convert an xsd:boolean to a Python boolean\r
-def str2bool(str):\r
- if str.lower() in ['true','1']:\r
- return True\r
- return False\r
-\r
-\r
-##\r
-# Utility function to get the text of an XML element\r
-\r
-def getTextNode(element, subele):\r
- sub = element.getElementsByTagName(subele)[0]\r
- if len(sub.childNodes) > 0: \r
- return sub.childNodes[0].nodeValue\r
- else:\r
- return None\r
- \r
-##\r
-# Utility function to set the text of an XML element\r
-# It creates the element, adds the text to it,\r
-# and then appends it to the parent.\r
-\r
-def append_sub(doc, parent, element, text):\r
- ele = doc.createElement(element)\r
- ele.appendChild(doc.createTextNode(text))\r
- parent.appendChild(ele)\r
-\r
-##\r
-# Signature contains information about an xmlsec1 signature\r
-# for a signed-credential\r
-#\r
-\r
-class Signature(object):\r
- \r
- def __init__(self, string=None):\r
- self.refid = None\r
- self.issuer_gid = None\r
- self.xml = None\r
- if string:\r
- self.xml = string\r
- self.decode()\r
-\r
-\r
- def get_refid(self):\r
- if not self.refid:\r
- self.decode()\r
- return self.refid\r
-\r
- def get_xml(self):\r
- if not self.xml:\r
- self.encode()\r
- return self.xml\r
-\r
- def set_refid(self, id):\r
- self.refid = id\r
-\r
- def get_issuer_gid(self):\r
- if not self.gid:\r
- self.decode()\r
- return self.gid \r
-\r
- def set_issuer_gid(self, gid):\r
- self.gid = gid\r
-\r
- def decode(self):\r
- try:\r
- doc = parseString(self.xml)\r
- except ExpatError,e:\r
- logger.log_exc ("Failed to parse credential, %s"%self.xml)\r
- raise\r
- sig = doc.getElementsByTagName("Signature")[0]\r
- self.set_refid(sig.getAttribute("xml:id").strip("Sig_"))\r
- keyinfo = sig.getElementsByTagName("X509Data")[0]\r
- szgid = getTextNode(keyinfo, "X509Certificate")\r
- szgid = "-----BEGIN CERTIFICATE-----\n%s\n-----END CERTIFICATE-----" % szgid\r
- self.set_issuer_gid(GID(string=szgid)) \r
- \r
- def encode(self):\r
- self.xml = signature_template % (self.get_refid(), self.get_refid())\r
-\r
-\r
-##\r
-# A credential provides a caller gid with privileges to an object gid.\r
-# A signed credential is signed by the object's authority.\r
-#\r
-# Credentials are encoded in one of two ways. The legacy style places\r
-# it in the subjectAltName of an X509 certificate. The new credentials\r
-# are placed in signed XML.\r
-#\r
-# WARNING:\r
-# In general, a signed credential obtained externally should\r
-# not be changed else the signature is no longer valid. So, once\r
-# you have loaded an existing signed credential, do not call encode() or sign() on it.\r
-\r
-def filter_creds_by_caller(creds, caller_hrn_list):\r
- """\r
- Returns a list of creds who's gid caller matches the\r
- specified caller hrn\r
- """\r
- if not isinstance(creds, list): creds = [creds]\r
- if not isinstance(caller_hrn_list, list): \r
- caller_hrn_list = [caller_hrn_list]\r
- caller_creds = []\r
- for cred in creds:\r
- try:\r
- tmp_cred = Credential(string=cred)\r
- if tmp_cred.get_gid_caller().get_hrn() in caller_hrn_list:\r
- caller_creds.append(cred)\r
- except: pass\r
- return caller_creds\r
-\r
-class Credential(object):\r
-\r
- ##\r
- # Create a Credential object\r
- #\r
- # @param create If true, create a blank x509 certificate\r
- # @param subject If subject!=None, create an x509 cert with the subject name\r
- # @param string If string!=None, load the credential from the string\r
- # @param filename If filename!=None, load the credential from the file\r
- # FIXME: create and subject are ignored!\r
- def __init__(self, create=False, subject=None, string=None, filename=None):\r
- self.gidCaller = None\r
- self.gidObject = None\r
- self.expiration = None\r
- self.privileges = None\r
- self.issuer_privkey = None\r
- self.issuer_gid = None\r
- self.issuer_pubkey = None\r
- self.parent = None\r
- self.signature = None\r
- self.xml = None\r
- self.refid = None\r
- self.legacy = None\r
-\r
- # Check if this is a legacy credential, translate it if so\r
- if string or filename:\r
- if string: \r
- str = string\r
- elif filename:\r
- str = file(filename).read()\r
- \r
- if str.strip().startswith("-----"):\r
- self.legacy = CredentialLegacy(False,string=str)\r
- self.translate_legacy(str)\r
- else:\r
- self.xml = str\r
- self.decode()\r
-\r
- # Find an xmlsec1 path\r
- self.xmlsec_path = ''\r
- paths = ['/usr/bin','/usr/local/bin','/bin','/opt/bin','/opt/local/bin']\r
- for path in paths:\r
- if os.path.isfile(path + '/' + 'xmlsec1'):\r
- self.xmlsec_path = path + '/' + 'xmlsec1'\r
- break\r
-\r
- def get_subject(self):\r
- if not self.gidObject:\r
- self.decode()\r
- return self.gidObject.get_printable_subject()\r
-\r
- # sounds like this should be __repr__ instead ??\r
- def get_summary_tostring(self):\r
- if not self.gidObject:\r
- self.decode()\r
- obj = self.gidObject.get_printable_subject()\r
- caller = self.gidCaller.get_printable_subject()\r
- exp = self.get_expiration()\r
- # Summarize the rights too? The issuer?\r
- return "[ Grant %s rights on %s until %s ]" % (caller, obj, exp)\r
-\r
- def get_signature(self):\r
- if not self.signature:\r
- self.decode()\r
- return self.signature\r
-\r
- def set_signature(self, sig):\r
- self.signature = sig\r
-\r
- \r
- ##\r
- # Translate a legacy credential into a new one\r
- #\r
- # @param String of the legacy credential\r
-\r
- def translate_legacy(self, str):\r
- legacy = CredentialLegacy(False,string=str)\r
- self.gidCaller = legacy.get_gid_caller()\r
- self.gidObject = legacy.get_gid_object()\r
- lifetime = legacy.get_lifetime()\r
- if not lifetime:\r
- self.set_expiration(datetime.datetime.utcnow() + datetime.timedelta(seconds=DEFAULT_CREDENTIAL_LIFETIME))\r
- else:\r
- self.set_expiration(int(lifetime))\r
- self.lifeTime = legacy.get_lifetime()\r
- self.set_privileges(legacy.get_privileges())\r
- self.get_privileges().delegate_all_privileges(legacy.get_delegate())\r
-\r
- ##\r
- # Need the issuer's private key and name\r
- # @param key Keypair object containing the private key of the issuer\r
- # @param gid GID of the issuing authority\r
-\r
- def set_issuer_keys(self, privkey, gid):\r
- self.issuer_privkey = privkey\r
- self.issuer_gid = gid\r
-\r
-\r
- ##\r
- # Set this credential's parent\r
- def set_parent(self, cred):\r
- self.parent = cred\r
- self.updateRefID()\r
-\r
- ##\r
- # set the GID of the caller\r
- #\r
- # @param gid GID object of the caller\r
-\r
- def set_gid_caller(self, gid):\r
- self.gidCaller = gid\r
- # gid origin caller is the caller's gid by default\r
- self.gidOriginCaller = gid\r
-\r
- ##\r
- # get the GID of the object\r
-\r
- def get_gid_caller(self):\r
- if not self.gidCaller:\r
- self.decode()\r
- return self.gidCaller\r
-\r
- ##\r
- # set the GID of the object\r
- #\r
- # @param gid GID object of the object\r
-\r
- def set_gid_object(self, gid):\r
- self.gidObject = gid\r
-\r
- ##\r
- # get the GID of the object\r
-\r
- def get_gid_object(self):\r
- if not self.gidObject:\r
- self.decode()\r
- return self.gidObject\r
- \r
- ##\r
- # Expiration: an absolute UTC time of expiration (as either an int or string or datetime)\r
- # \r
- def set_expiration(self, expiration):\r
- if isinstance(expiration, (int, float)):\r
- self.expiration = datetime.datetime.fromtimestamp(expiration)\r
- elif isinstance (expiration, datetime.datetime):\r
- self.expiration = expiration\r
- elif isinstance (expiration, StringTypes):\r
- self.expiration = utcparse (expiration)\r
- else:\r
- logger.error ("unexpected input type in Credential.set_expiration")\r
-\r
-\r
- ##\r
- # get the lifetime of the credential (always in datetime format)\r
-\r
- def get_expiration(self):\r
- if not self.expiration:\r
- self.decode()\r
- # at this point self.expiration is normalized as a datetime - DON'T call utcparse again\r
- return self.expiration\r
-\r
- ##\r
- # For legacy sake\r
- def get_lifetime(self):\r
- return self.get_expiration()\r
- \r
- ##\r
- # set the privileges\r
- #\r
- # @param privs either a comma-separated list of privileges of a Rights object\r
-\r
- def set_privileges(self, privs):\r
- if isinstance(privs, str):\r
- self.privileges = Rights(string = privs)\r
- else:\r
- self.privileges = privs \r
-\r
- ##\r
- # return the privileges as a Rights object\r
-\r
- def get_privileges(self):\r
- if not self.privileges:\r
- self.decode()\r
- return self.privileges\r
-\r
- ##\r
- # determine whether the credential allows a particular operation to be\r
- # performed\r
- #\r
- # @param op_name string specifying name of operation ("lookup", "update", etc)\r
-\r
- def can_perform(self, op_name):\r
- rights = self.get_privileges()\r
- \r
- if not rights:\r
- return False\r
-\r
- return rights.can_perform(op_name)\r
-\r
-\r
- ##\r
- # Encode the attributes of the credential into an XML string \r
- # This should be done immediately before signing the credential. \r
- # WARNING:\r
- # In general, a signed credential obtained externally should\r
- # not be changed else the signature is no longer valid. So, once\r
- # you have loaded an existing signed credential, do not call encode() or sign() on it.\r
-\r
- def encode(self):\r
- # Create the XML document\r
- doc = Document()\r
- signed_cred = doc.createElement("signed-credential")\r
-\r
-# Declare namespaces\r
-# Note that credential/policy.xsd are really the PG schemas\r
-# in a PL namespace.\r
-# Note that delegation of credentials between the 2 only really works\r
-# cause those schemas are identical.\r
-# Also note these PG schemas talk about PG tickets and CM policies.\r
- signed_cred.setAttribute("xmlns:xsi", "http://www.w3.org/2001/XMLSchema-instance")\r
- signed_cred.setAttribute("xsi:noNamespaceSchemaLocation", "http://www.planet-lab.org/resources/sfa/credential.xsd")\r
- 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
-\r
-# PG says for those last 2:\r
-# signed_cred.setAttribute("xsi:noNamespaceSchemaLocation", "http://www.protogeni.net/resources/credential/credential.xsd")\r
-# 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
-\r
- doc.appendChild(signed_cred) \r
- \r
- # Fill in the <credential> bit \r
- cred = doc.createElement("credential")\r
- cred.setAttribute("xml:id", self.get_refid())\r
- signed_cred.appendChild(cred)\r
- append_sub(doc, cred, "type", "privilege")\r
- append_sub(doc, cred, "serial", "8")\r
- append_sub(doc, cred, "owner_gid", self.gidCaller.save_to_string())\r
- append_sub(doc, cred, "owner_urn", self.gidCaller.get_urn())\r
- append_sub(doc, cred, "target_gid", self.gidObject.save_to_string())\r
- append_sub(doc, cred, "target_urn", self.gidObject.get_urn())\r
- append_sub(doc, cred, "uuid", "")\r
- if not self.expiration:\r
- self.set_expiration(datetime.datetime.utcnow() + datetime.timedelta(seconds=DEFAULT_CREDENTIAL_LIFETIME))\r
- self.expiration = self.expiration.replace(microsecond=0)\r
- append_sub(doc, cred, "expires", self.expiration.isoformat())\r
- privileges = doc.createElement("privileges")\r
- cred.appendChild(privileges)\r
-\r
- if self.privileges:\r
- rights = self.get_privileges()\r
- for right in rights.rights:\r
- priv = doc.createElement("privilege")\r
- append_sub(doc, priv, "name", right.kind)\r
- append_sub(doc, priv, "can_delegate", str(right.delegate).lower())\r
- privileges.appendChild(priv)\r
-\r
- # Add the parent credential if it exists\r
- if self.parent:\r
- sdoc = parseString(self.parent.get_xml())\r
- # If the root node is a signed-credential (it should be), then\r
- # get all its attributes and attach those to our signed_cred\r
- # node.\r
- # Specifically, PG and PLadd attributes for namespaces (which is reasonable),\r
- # and we need to include those again here or else their signature\r
- # no longer matches on the credential.\r
- # We expect three of these, but here we copy them all:\r
-# signed_cred.setAttribute("xmlns:xsi", "http://www.w3.org/2001/XMLSchema-instance")\r
-# and from PG (PL is equivalent, as shown above):\r
-# signed_cred.setAttribute("xsi:noNamespaceSchemaLocation", "http://www.protogeni.net/resources/credential/credential.xsd")\r
-# 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
-\r
- # HOWEVER!\r
- # PL now also declares these, with different URLs, so\r
- # the code notices those attributes already existed with\r
- # different values, and complains.\r
- # This happens regularly on delegation now that PG and\r
- # PL both declare the namespace with different URLs.\r
- # If the content ever differs this is a problem,\r
- # but for now it works - different URLs (values in the attributes)\r
- # but the same actual schema, so using the PG schema\r
- # on delegated-to-PL credentials works fine.\r
-\r
- # Note: you could also not copy attributes\r
- # which already exist. It appears that both PG and PL\r
- # will actually validate a slicecred with a parent\r
- # signed using PG namespaces and a child signed with PL\r
- # namespaces over the whole thing. But I don't know\r
- # if that is a bug in xmlsec1, an accident since\r
- # the contents of the schemas are the same,\r
- # or something else, but it seems odd. And this works.\r
- parentRoot = sdoc.documentElement\r
- if parentRoot.tagName == "signed-credential" and parentRoot.hasAttributes():\r
- for attrIx in range(0, parentRoot.attributes.length):\r
- attr = parentRoot.attributes.item(attrIx)\r
- # returns the old attribute of same name that was\r
- # on the credential\r
- # Below throws InUse exception if we forgot to clone the attribute first\r
- oldAttr = signed_cred.setAttributeNode(attr.cloneNode(True))\r
- if oldAttr and oldAttr.value != attr.value:\r
- 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
- logger.warn(msg)\r
- #raise CredentialNotVerifiable("Can't encode new valid delegated credential: %s" % msg)\r
-\r
- p_cred = doc.importNode(sdoc.getElementsByTagName("credential")[0], True)\r
- p = doc.createElement("parent")\r
- p.appendChild(p_cred)\r
- cred.appendChild(p)\r
- # done handling parent credential\r
-\r
- # Create the <signatures> tag\r
- signatures = doc.createElement("signatures")\r
- signed_cred.appendChild(signatures)\r
-\r
- # Add any parent signatures\r
- if self.parent:\r
- for cur_cred in self.get_credential_list()[1:]:\r
- sdoc = parseString(cur_cred.get_signature().get_xml())\r
- ele = doc.importNode(sdoc.getElementsByTagName("Signature")[0], True)\r
- signatures.appendChild(ele)\r
- \r
- # Get the finished product\r
- self.xml = doc.toxml()\r
-\r
-\r
- def save_to_random_tmp_file(self): \r
- fp, filename = mkstemp(suffix='cred', text=True)\r
- fp = os.fdopen(fp, "w")\r
- self.save_to_file(filename, save_parents=True, filep=fp)\r
- return filename\r
- \r
- def save_to_file(self, filename, save_parents=True, filep=None):\r
- if not self.xml:\r
- self.encode()\r
- if filep:\r
- f = filep \r
- else:\r
- f = open(filename, "w")\r
- f.write(self.xml)\r
- f.close()\r
-\r
- def save_to_string(self, save_parents=True):\r
- if not self.xml:\r
- self.encode()\r
- return self.xml\r
-\r
- def get_refid(self):\r
- if not self.refid:\r
- self.refid = 'ref0'\r
- return self.refid\r
-\r
- def set_refid(self, rid):\r
- self.refid = rid\r
-\r
- ##\r
- # Figure out what refids exist, and update this credential's id\r
- # so that it doesn't clobber the others. Returns the refids of\r
- # the parents.\r
- \r
- def updateRefID(self):\r
- if not self.parent:\r
- self.set_refid('ref0')\r
- return []\r
- \r
- refs = []\r
-\r
- next_cred = self.parent\r
- while next_cred:\r
- refs.append(next_cred.get_refid())\r
- if next_cred.parent:\r
- next_cred = next_cred.parent\r
- else:\r
- next_cred = None\r
-\r
- \r
- # Find a unique refid for this credential\r
- rid = self.get_refid()\r
- while rid in refs:\r
- val = int(rid[3:])\r
- rid = "ref%d" % (val + 1)\r
-\r
- # Set the new refid\r
- self.set_refid(rid)\r
-\r
- # Return the set of parent credential ref ids\r
- return refs\r
-\r
- def get_xml(self):\r
- if not self.xml:\r
- self.encode()\r
- return self.xml\r
-\r
- ##\r
- # Sign the XML file created by encode()\r
- #\r
- # WARNING:\r
- # In general, a signed credential obtained externally should\r
- # not be changed else the signature is no longer valid. So, once\r
- # you have loaded an existing signed credential, do not call encode() or sign() on it.\r
-\r
- def sign(self):\r
- if not self.issuer_privkey or not self.issuer_gid:\r
- return\r
- doc = parseString(self.get_xml())\r
- sigs = doc.getElementsByTagName("signatures")[0]\r
-\r
- # Create the signature template to be signed\r
- signature = Signature()\r
- signature.set_refid(self.get_refid())\r
- sdoc = parseString(signature.get_xml()) \r
- sig_ele = doc.importNode(sdoc.getElementsByTagName("Signature")[0], True)\r
- sigs.appendChild(sig_ele)\r
-\r
- self.xml = doc.toxml()\r
-\r
-\r
- # Split the issuer GID into multiple certificates if it's a chain\r
- chain = GID(filename=self.issuer_gid)\r
- gid_files = []\r
- while chain:\r
- gid_files.append(chain.save_to_random_tmp_file(False))\r
- if chain.get_parent():\r
- chain = chain.get_parent()\r
- else:\r
- chain = None\r
-\r
-\r
- # Call out to xmlsec1 to sign it\r
- ref = 'Sig_%s' % self.get_refid()\r
- filename = self.save_to_random_tmp_file()\r
- signed = os.popen('%s --sign --node-id "%s" --privkey-pem %s,%s %s' \\r
- % (self.xmlsec_path, ref, self.issuer_privkey, ",".join(gid_files), filename)).read()\r
- os.remove(filename)\r
-\r
- for gid_file in gid_files:\r
- os.remove(gid_file)\r
-\r
- self.xml = signed\r
-\r
- # This is no longer a legacy credential\r
- if self.legacy:\r
- self.legacy = None\r
-\r
- # Update signatures\r
- self.decode() \r
-\r
- \r
- ##\r
- # Retrieve the attributes of the credential from the XML.\r
- # This is automatically called by the various get_* methods of\r
- # this class and should not need to be called explicitly.\r
-\r
- def decode(self):\r
- if not self.xml:\r
- return\r
- doc = parseString(self.xml)\r
- sigs = []\r
- signed_cred = doc.getElementsByTagName("signed-credential")\r
-\r
- # Is this a signed-cred or just a cred?\r
- if len(signed_cred) > 0:\r
- creds = signed_cred[0].getElementsByTagName("credential")\r
- signatures = signed_cred[0].getElementsByTagName("signatures")\r
- if len(signatures) > 0:\r
- sigs = signatures[0].getElementsByTagName("Signature")\r
- else:\r
- creds = doc.getElementsByTagName("credential")\r
- \r
- if creds is None or len(creds) == 0:\r
- # malformed cred file\r
- raise CredentialNotVerifiable("Malformed XML: No credential tag found")\r
-\r
- # Just take the first cred if there are more than one\r
- cred = creds[0]\r
-\r
- self.set_refid(cred.getAttribute("xml:id"))\r
- self.set_expiration(utcparse(getTextNode(cred, "expires")))\r
- self.gidCaller = GID(string=getTextNode(cred, "owner_gid"))\r
- self.gidObject = GID(string=getTextNode(cred, "target_gid")) \r
-\r
-\r
- # Process privileges\r
- privs = cred.getElementsByTagName("privileges")[0]\r
- rlist = Rights()\r
- for priv in privs.getElementsByTagName("privilege"):\r
- kind = getTextNode(priv, "name")\r
- deleg = str2bool(getTextNode(priv, "can_delegate"))\r
- if kind == '*':\r
- # Convert * into the default privileges for the credential's type\r
- # Each inherits the delegatability from the * above\r
- _ , type = urn_to_hrn(self.gidObject.get_urn())\r
- rl = determine_rights(type, self.gidObject.get_urn())\r
- for r in rl.rights:\r
- r.delegate = deleg\r
- rlist.add(r)\r
- else:\r
- rlist.add(Right(kind.strip(), deleg))\r
- self.set_privileges(rlist)\r
-\r
-\r
- # Is there a parent?\r
- parent = cred.getElementsByTagName("parent")\r
- if len(parent) > 0:\r
- parent_doc = parent[0].getElementsByTagName("credential")[0]\r
- parent_xml = parent_doc.toxml()\r
- self.parent = Credential(string=parent_xml)\r
- self.updateRefID()\r
-\r
- # Assign the signatures to the credentials\r
- for sig in sigs:\r
- Sig = Signature(string=sig.toxml())\r
-\r
- for cur_cred in self.get_credential_list():\r
- if cur_cred.get_refid() == Sig.get_refid():\r
- cur_cred.set_signature(Sig)\r
- \r
- \r
- ##\r
- # Verify\r
- # trusted_certs: A list of trusted GID filenames (not GID objects!) \r
- # Chaining is not supported within the GIDs by xmlsec1.\r
- #\r
- # trusted_certs_required: Should usually be true. Set False means an\r
- # empty list of trusted_certs would still let this method pass.\r
- # It just skips xmlsec1 verification et al. Only used by some utils\r
- # \r
- # Verify that:\r
- # . All of the signatures are valid and that the issuers trace back\r
- # to trusted roots (performed by xmlsec1)\r
- # . The XML matches the credential schema\r
- # . That the issuer of the credential is the authority in the target's urn\r
- # . In the case of a delegated credential, this must be true of the root\r
- # . That all of the gids presented in the credential are valid\r
- # . Including verifying GID chains, and includ the issuer\r
- # . The credential is not expired\r
- #\r
- # -- For Delegates (credentials with parents)\r
- # . The privileges must be a subset of the parent credentials\r
- # . The privileges must have "can_delegate" set for each delegated privilege\r
- # . The target gid must be the same between child and parents\r
- # . The expiry time on the child must be no later than the parent\r
- # . The signer of the child must be the owner of the parent\r
- #\r
- # -- Verify does *NOT*\r
- # . ensure that an xmlrpc client's gid matches a credential gid, that\r
- # must be done elsewhere\r
- #\r
- # @param trusted_certs: The certificates of trusted CA certificates\r
- def verify(self, trusted_certs=None, schema=None, trusted_certs_required=True):\r
- if not self.xml:\r
- self.decode()\r
-\r
- # validate against RelaxNG schema\r
- if HAVELXML and not self.legacy:\r
- if schema and os.path.exists(schema):\r
- tree = etree.parse(StringIO(self.xml))\r
- schema_doc = etree.parse(schema)\r
- xmlschema = etree.XMLSchema(schema_doc)\r
- if not xmlschema.validate(tree):\r
- error = xmlschema.error_log.last_error\r
- message = "%s: %s (line %s)" % (self.get_summary_tostring(), error.message, error.line)\r
- raise CredentialNotVerifiable(message)\r
-\r
- if trusted_certs_required and trusted_certs is None:\r
- trusted_certs = []\r
-\r
-# trusted_cert_objects = [GID(filename=f) for f in trusted_certs]\r
- trusted_cert_objects = []\r
- ok_trusted_certs = []\r
- # If caller explicitly passed in None that means skip cert chain validation.\r
- # Strange and not typical\r
- if trusted_certs is not None:\r
- for f in trusted_certs:\r
- try:\r
- # Failures here include unreadable files\r
- # or non PEM files\r
- trusted_cert_objects.append(GID(filename=f))\r
- ok_trusted_certs.append(f)\r
- except Exception, exc:\r
- logger.error("Failed to load trusted cert from %s: %r", f, exc)\r
- trusted_certs = ok_trusted_certs\r
-\r
- # Use legacy verification if this is a legacy credential\r
- if self.legacy:\r
- self.legacy.verify_chain(trusted_cert_objects)\r
- if self.legacy.client_gid:\r
- self.legacy.client_gid.verify_chain(trusted_cert_objects)\r
- if self.legacy.object_gid:\r
- self.legacy.object_gid.verify_chain(trusted_cert_objects)\r
- return True\r
- \r
- # make sure it is not expired\r
- if self.get_expiration() < datetime.datetime.utcnow():\r
- raise CredentialNotVerifiable("Credential %s expired at %s" % (self.get_summary_tostring(), self.expiration.isoformat()))\r
-\r
- # Verify the signatures\r
- filename = self.save_to_random_tmp_file()\r
- if trusted_certs is not None:\r
- cert_args = " ".join(['--trusted-pem %s' % x for x in trusted_certs])\r
-\r
- # If caller explicitly passed in None that means skip cert chain validation.\r
- # - Strange and not typical\r
- if trusted_certs is not None:\r
- # Verify the gids of this cred and of its parents\r
- for cur_cred in self.get_credential_list():\r
- cur_cred.get_gid_object().verify_chain(trusted_cert_objects)\r
- cur_cred.get_gid_caller().verify_chain(trusted_cert_objects)\r
-\r
- refs = []\r
- refs.append("Sig_%s" % self.get_refid())\r
-\r
- parentRefs = self.updateRefID()\r
- for ref in parentRefs:\r
- refs.append("Sig_%s" % ref)\r
-\r
- for ref in refs:\r
- # If caller explicitly passed in None that means skip xmlsec1 validation.\r
- # Strange and not typical\r
- if trusted_certs is None:\r
- break\r
-\r
-# print "Doing %s --verify --node-id '%s' %s %s 2>&1" % \\r
-# (self.xmlsec_path, ref, cert_args, filename)\r
- verified = os.popen('%s --verify --node-id "%s" %s %s 2>&1' \\r
- % (self.xmlsec_path, ref, cert_args, filename)).read()\r
- if not verified.strip().startswith("OK"):\r
- # xmlsec errors have a msg= which is the interesting bit.\r
- mstart = verified.find("msg=")\r
- msg = ""\r
- if mstart > -1 and len(verified) > 4:\r
- mstart = mstart + 4\r
- mend = verified.find('\\', mstart)\r
- msg = verified[mstart:mend]\r
- raise CredentialNotVerifiable("xmlsec1 error verifying cred %s using Signature ID %s: %s %s" % (self.get_summary_tostring(), ref, msg, verified.strip()))\r
- os.remove(filename)\r
-\r
- # Verify the parents (delegation)\r
- if self.parent:\r
- self.verify_parent(self.parent)\r
-\r
- # Make sure the issuer is the target's authority, and is\r
- # itself a valid GID\r
- self.verify_issuer(trusted_cert_objects)\r
- return True\r
-\r
- ##\r
- # Creates a list of the credential and its parents, with the root \r
- # (original delegated credential) as the last item in the list\r
- def get_credential_list(self): \r
- cur_cred = self\r
- list = []\r
- while cur_cred:\r
- list.append(cur_cred)\r
- if cur_cred.parent:\r
- cur_cred = cur_cred.parent\r
- else:\r
- cur_cred = None\r
- return list\r
- \r
- ##\r
- # Make sure the credential's target gid (a) was signed by or (b)\r
- # is the same as the entity that signed the original credential,\r
- # or (c) is an authority over the target's namespace.\r
- # Also ensure that the credential issuer / signer itself has a valid\r
- # GID signature chain (signed by an authority with namespace rights).\r
- def verify_issuer(self, trusted_gids):\r
- root_cred = self.get_credential_list()[-1]\r
- root_target_gid = root_cred.get_gid_object()\r
- root_cred_signer = root_cred.get_signature().get_issuer_gid()\r
-\r
- # Case 1:\r
- # Allow non authority to sign target and cred about target.\r
- #\r
- # Why do we need to allow non authorities to sign?\r
- # If in the target gid validation step we correctly\r
- # checked that the target is only signed by an authority,\r
- # then this is just a special case of case 3.\r
- # This short-circuit is the common case currently -\r
- # and cause GID validation doesn't check 'authority',\r
- # this allows users to generate valid slice credentials.\r
- if root_target_gid.is_signed_by_cert(root_cred_signer):\r
- # cred signer matches target signer, return success\r
- return\r
-\r
- # Case 2:\r
- # Allow someone to sign credential about themeselves. Used?\r
- # If not, remove this.\r
- #root_target_gid_str = root_target_gid.save_to_string()\r
- #root_cred_signer_str = root_cred_signer.save_to_string()\r
- #if root_target_gid_str == root_cred_signer_str:\r
- # # cred signer is target, return success\r
- # return\r
-\r
- # Case 3:\r
-\r
- # root_cred_signer is not the target_gid\r
- # So this is a different gid that we have not verified.\r
- # xmlsec1 verified the cert chain on this already, but\r
- # it hasn't verified that the gid meets the HRN namespace\r
- # requirements.\r
- # Below we'll ensure that it is an authority.\r
- # But we haven't verified that it is _signed by_ an authority\r
- # We also don't know if xmlsec1 requires that cert signers\r
- # are marked as CAs.\r
-\r
- # Note that if verify() gave us no trusted_gids then this\r
- # call will fail. So skip it if we have no trusted_gids\r
- if trusted_gids and len(trusted_gids) > 0:\r
- root_cred_signer.verify_chain(trusted_gids)\r
- else:\r
- logger.debug("No trusted gids. Cannot verify that cred signer is signed by a trusted authority. Skipping that check.")\r
-\r
- # See if the signer is an authority over the domain of the target.\r
- # There are multiple types of authority - accept them all here\r
- # Maybe should be (hrn, type) = urn_to_hrn(root_cred_signer.get_urn())\r
- root_cred_signer_type = root_cred_signer.get_type()\r
- if (root_cred_signer_type.find('authority') == 0):\r
- #logger.debug('Cred signer is an authority')\r
- # signer is an authority, see if target is in authority's domain\r
- signerhrn = root_cred_signer.get_hrn()\r
- if hrn_authfor_hrn(signerhrn, root_target_gid.get_hrn()):\r
- return\r
-\r
- # We've required that the credential be signed by an authority\r
- # for that domain. Reasonable and probably correct.\r
- # A looser model would also allow the signer to be an authority\r
- # in my control framework - eg My CA or CH. Even if it is not\r
- # the CH that issued these, eg, user credentials.\r
-\r
- # Give up, credential does not pass issuer verification\r
-\r
- 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
-\r
-\r
- ##\r
- # -- For Delegates (credentials with parents) verify that:\r
- # . The privileges must be a subset of the parent credentials\r
- # . The privileges must have "can_delegate" set for each delegated privilege\r
- # . The target gid must be the same between child and parents\r
- # . The expiry time on the child must be no later than the parent\r
- # . The signer of the child must be the owner of the parent \r
- def verify_parent(self, parent_cred):\r
- # make sure the rights given to the child are a subset of the\r
- # parents rights (and check delegate bits)\r
- if not parent_cred.get_privileges().is_superset(self.get_privileges()):\r
- raise ChildRightsNotSubsetOfParent(("Parent cred ref %s rights " % parent_cred.get_refid()) +\r
- self.parent.get_privileges().save_to_string() + (" not superset of delegated cred %s ref %s rights " % (self.get_summary_tostring(), self.get_refid())) +\r
- self.get_privileges().save_to_string())\r
-\r
- # make sure my target gid is the same as the parent's\r
- if not parent_cred.get_gid_object().save_to_string() == \\r
- self.get_gid_object().save_to_string():\r
- 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
-\r
- # make sure my expiry time is <= my parent's\r
- if not parent_cred.get_expiration() >= self.get_expiration():\r
- raise CredentialNotVerifiable("Delegated credential %s expires after parent %s" % (self.get_summary_tostring(), parent_cred.get_summary_tostring()))\r
-\r
- # make sure my signer is the parent's caller\r
- if not parent_cred.get_gid_caller().save_to_string(False) == \\r
- self.get_signature().get_issuer_gid().save_to_string(False):\r
- raise CredentialNotVerifiable("Delegated credential %s not signed by parent %s's caller" % (self.get_summary_tostring(), parent_cred.get_summary_tostring()))\r
- \r
- # Recurse\r
- if parent_cred.parent:\r
- parent_cred.verify_parent(parent_cred.parent)\r
-\r
-\r
- def delegate(self, delegee_gidfile, caller_keyfile, caller_gidfile):\r
- """\r
- Return a delegated copy of this credential, delegated to the \r
- specified gid's user. \r
- """\r
- # get the gid of the object we are delegating\r
- object_gid = self.get_gid_object()\r
- object_hrn = object_gid.get_hrn() \r
- \r
- # the hrn of the user who will be delegated to\r
- delegee_gid = GID(filename=delegee_gidfile)\r
- delegee_hrn = delegee_gid.get_hrn()\r
- \r
- #user_key = Keypair(filename=keyfile)\r
- #user_hrn = self.get_gid_caller().get_hrn()\r
- subject_string = "%s delegated to %s" % (object_hrn, delegee_hrn)\r
- dcred = Credential(subject=subject_string)\r
- dcred.set_gid_caller(delegee_gid)\r
- dcred.set_gid_object(object_gid)\r
- dcred.set_parent(self)\r
- dcred.set_expiration(self.get_expiration())\r
- dcred.set_privileges(self.get_privileges())\r
- dcred.get_privileges().delegate_all_privileges(True)\r
- #dcred.set_issuer_keys(keyfile, delegee_gidfile)\r
- dcred.set_issuer_keys(caller_keyfile, caller_gidfile)\r
- dcred.encode()\r
- dcred.sign()\r
-\r
- return dcred\r
-\r
- # only informative\r
- def get_filename(self):\r
- return getattr(self,'filename',None)\r
-\r
- ##\r
- # Dump the contents of a credential to stdout in human-readable format\r
- #\r
- # @param dump_parents If true, also dump the parent certificates\r
- def dump (self, *args, **kwargs):\r
- print self.dump_string(*args, **kwargs)\r
-\r
-\r
- def dump_string(self, dump_parents=False):\r
- result=""\r
- result += "CREDENTIAL %s\n" % self.get_subject()\r
- filename=self.get_filename()\r
- if filename: result += "Filename %s\n"%filename\r
- result += " privs: %s\n" % self.get_privileges().save_to_string()\r
- gidCaller = self.get_gid_caller()\r
- if gidCaller:\r
- result += " gidCaller:\n"\r
- result += gidCaller.dump_string(8, dump_parents)\r
-\r
- if self.get_signature():\r
- print " gidIssuer:"\r
- self.get_signature().get_issuer_gid().dump(8, dump_parents)\r
-\r
- gidObject = self.get_gid_object()\r
- if gidObject:\r
- result += " gidObject:\n"\r
- result += gidObject.dump_string(8, dump_parents)\r
-\r
- if self.parent and dump_parents:\r
- result += "\nPARENT"\r
- result += self.parent.dump_string(True)\r
-\r
- return result\r
+#----------------------------------------------------------------------
+# Copyright (c) 2008 Board of Trustees, Princeton University
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and/or hardware specification (the "Work") to
+# deal in the Work without restriction, including without limitation the
+# rights to use, copy, modify, merge, publish, distribute, sublicense,
+# and/or sell copies of the Work, and to permit persons to whom the Work
+# is furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Work.
+#
+# THE WORK IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE WORK OR THE USE OR OTHER DEALINGS
+# IN THE WORK.
+#----------------------------------------------------------------------
+##
+# Implements SFA Credentials
+#
+# Credentials are signed XML files that assign a subject gid privileges to an object gid
+##
+
+import os
+from types import StringTypes
+import datetime
+from StringIO import StringIO
+from tempfile import mkstemp
+from xml.dom.minidom import Document, parseString
+
+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.credential_legacy import CredentialLegacy
+from sfa.trust.rights import Right, Rights, determine_rights
+from sfa.trust.gid import GID
+from sfa.util.xrn import urn_to_hrn, hrn_authfor_hrn
+
+# 2 weeks, in seconds
+DEFAULT_CREDENTIAL_LIFETIME = 86400 * 31
+
+
+# TODO:
+# . make privs match between PG and PL
+# . Need to add support for other types of credentials, e.g. tickets
+# . add namespaces to signed-credential element?
+
+signature_template = \
+'''
+<Signature xml:id="Sig_%s" xmlns="http://www.w3.org/2000/09/xmldsig#">
+ <SignedInfo>
+ <CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
+ <SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/>
+ <Reference URI="#%s">
+ <Transforms>
+ <Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature" />
+ </Transforms>
+ <DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>
+ <DigestValue></DigestValue>
+ </Reference>
+ </SignedInfo>
+ <SignatureValue />
+ <KeyInfo>
+ <X509Data>
+ <X509SubjectName/>
+ <X509IssuerSerial/>
+ <X509Certificate/>
+ </X509Data>
+ <KeyValue />
+ </KeyInfo>
+</Signature>
+'''
+
+# PG formats the template (whitespace) slightly differently.
+# Note that they don't include the xmlns in the template, but add it later.
+# Otherwise the two are equivalent.
+#signature_template_as_in_pg = \
+#'''
+#<Signature xml:id="Sig_%s" >
+# <SignedInfo>
+# <CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
+# <SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/>
+# <Reference URI="#%s">
+# <Transforms>
+# <Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature" />
+# </Transforms>
+# <DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>
+# <DigestValue></DigestValue>
+# </Reference>
+# </SignedInfo>
+# <SignatureValue />
+# <KeyInfo>
+# <X509Data >
+# <X509SubjectName/>
+# <X509IssuerSerial/>
+# <X509Certificate/>
+# </X509Data>
+# <KeyValue />
+# </KeyInfo>
+#</Signature>
+#'''
+
+##
+# Convert a string into a bool
+# used to convert an xsd:boolean to a Python boolean
+def str2bool(str):
+ if str.lower() in ['true','1']:
+ return True
+ return False
+
+
+##
+# Utility function to get the text of an XML element
+
+def getTextNode(element, subele):
+ sub = element.getElementsByTagName(subele)[0]
+ if len(sub.childNodes) > 0:
+ return sub.childNodes[0].nodeValue
+ else:
+ return None
+
+##
+# Utility function to set the text of an XML element
+# It creates the element, adds the text to it,
+# and then appends it to the parent.
+
+def append_sub(doc, parent, element, text):
+ ele = doc.createElement(element)
+ ele.appendChild(doc.createTextNode(text))
+ parent.appendChild(ele)
+
+##
+# Signature contains information about an xmlsec1 signature
+# for a signed-credential
+#
+
+class Signature(object):
+
+ def __init__(self, string=None):
+ self.refid = None
+ self.issuer_gid = None
+ self.xml = None
+ if string:
+ self.xml = string
+ self.decode()
+
+
+ def get_refid(self):
+ if not self.refid:
+ self.decode()
+ return self.refid
+
+ def get_xml(self):
+ if not self.xml:
+ self.encode()
+ return self.xml
+
+ def set_refid(self, id):
+ self.refid = id
+
+ def get_issuer_gid(self):
+ if not self.gid:
+ self.decode()
+ return self.gid
+
+ def set_issuer_gid(self, gid):
+ self.gid = gid
+
+ def decode(self):
+ 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]
+ szgid = getTextNode(keyinfo, "X509Certificate")
+ szgid = "-----BEGIN CERTIFICATE-----\n%s\n-----END CERTIFICATE-----" % szgid
+ self.set_issuer_gid(GID(string=szgid))
+
+ def encode(self):
+ self.xml = signature_template % (self.get_refid(), self.get_refid())
+
+
+##
+# A credential provides a caller gid with privileges to an object gid.
+# A signed credential is signed by the object's authority.
+#
+# Credentials are encoded in one of two ways. The legacy style places
+# it in the subjectAltName of an X509 certificate. The new credentials
+# are placed in signed XML.
+#
+# WARNING:
+# In general, a signed credential obtained externally should
+# 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_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() in caller_hrn_list:
+ caller_creds.append(cred)
+ except: pass
+ return caller_creds
+
+class Credential(object):
+
+ ##
+ # Create a Credential object
+ #
+ # @param create If true, create a blank x509 certificate
+ # @param subject If subject!=None, create an x509 cert with the subject name
+ # @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):
+ self.gidCaller = None
+ self.gidObject = None
+ self.expiration = None
+ self.privileges = None
+ self.issuer_privkey = None
+ self.issuer_gid = None
+ self.issuer_pubkey = None
+ self.parent = None
+ self.signature = None
+ self.xml = None
+ self.refid = None
+ self.legacy = None
+
+ # Check if this is a legacy credential, translate it if so
+ if string or filename:
+ if string:
+ str = string
+ elif filename:
+ str = file(filename).read()
+
+ if str.strip().startswith("-----"):
+ self.legacy = CredentialLegacy(False,string=str)
+ self.translate_legacy(str)
+ else:
+ self.xml = str
+ self.decode()
+
+ # Find an xmlsec1 path
+ self.xmlsec_path = ''
+ paths = ['/usr/bin','/usr/local/bin','/bin','/opt/bin','/opt/local/bin']
+ for path in paths:
+ if os.path.isfile(path + '/' + 'xmlsec1'):
+ self.xmlsec_path = path + '/' + 'xmlsec1'
+ break
+
+ def get_subject(self):
+ if not self.gidObject:
+ self.decode()
+ 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:
+ self.decode()
+ return self.signature
+
+ def set_signature(self, sig):
+ self.signature = sig
+
+
+ ##
+ # Translate a legacy credential into a new one
+ #
+ # @param String of the legacy credential
+
+ def translate_legacy(self, str):
+ legacy = CredentialLegacy(False,string=str)
+ self.gidCaller = legacy.get_gid_caller()
+ self.gidObject = legacy.get_gid_object()
+ lifetime = legacy.get_lifetime()
+ if not lifetime:
+ self.set_expiration(datetime.datetime.utcnow() + datetime.timedelta(seconds=DEFAULT_CREDENTIAL_LIFETIME))
+ else:
+ self.set_expiration(int(lifetime))
+ self.lifeTime = legacy.get_lifetime()
+ self.set_privileges(legacy.get_privileges())
+ self.get_privileges().delegate_all_privileges(legacy.get_delegate())
+
+ ##
+ # Need the issuer's private key and name
+ # @param key Keypair object containing the private key of the issuer
+ # @param gid GID of the issuing authority
+
+ def set_issuer_keys(self, privkey, gid):
+ self.issuer_privkey = privkey
+ self.issuer_gid = gid
+
+
+ ##
+ # Set this credential's parent
+ def set_parent(self, cred):
+ self.parent = cred
+ self.updateRefID()
+
+ ##
+ # set the GID of the caller
+ #
+ # @param gid GID object of the caller
+
+ def set_gid_caller(self, gid):
+ self.gidCaller = gid
+ # gid origin caller is the caller's gid by default
+ self.gidOriginCaller = gid
+
+ ##
+ # get the GID of the object
+
+ def get_gid_caller(self):
+ if not self.gidCaller:
+ self.decode()
+ return self.gidCaller
+
+ ##
+ # set the GID of the object
+ #
+ # @param gid GID object of the object
+
+ def set_gid_object(self, gid):
+ self.gidObject = gid
+
+ ##
+ # get the GID of the object
+
+ def get_gid_object(self):
+ 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)):
+ self.expiration = datetime.datetime.fromtimestamp(expiration)
+ elif isinstance (expiration, datetime.datetime):
+ self.expiration = expiration
+ elif isinstance (expiration, StringTypes):
+ self.expiration = utcparse (expiration)
+ 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()
+ # at this point self.expiration is normalized as a datetime - DON'T call utcparse again
+ return self.expiration
+
+ ##
+ # For legacy sake
+ def get_lifetime(self):
+ return self.get_expiration()
+
+ ##
+ # set the privileges
+ #
+ # @param privs either a comma-separated list of privileges of a Rights object
+
+ def set_privileges(self, privs):
+ if isinstance(privs, str):
+ self.privileges = Rights(string = privs)
+ else:
+ self.privileges = privs
+
+ ##
+ # return the privileges as a Rights object
+
+ def get_privileges(self):
+ if not self.privileges:
+ self.decode()
+ return self.privileges
+
+ ##
+ # determine whether the credential allows a particular operation to be
+ # performed
+ #
+ # @param op_name string specifying name of operation ("lookup", "update", etc)
+
+ def can_perform(self, op_name):
+ rights = self.get_privileges()
+
+ if not rights:
+ return False
+
+ return rights.can_perform(op_name)
+
+
+ ##
+ # Encode the attributes of the credential into an XML string
+ # This should be done immediately before signing the credential.
+ # WARNING:
+ # In general, a signed credential obtained externally should
+ # 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 encode(self):
+ # Create the XML document
+ doc = Document()
+ signed_cred = doc.createElement("signed-credential")
+
+# 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)
+
+ # Fill in the <credential> bit
+ cred = doc.createElement("credential")
+ cred.setAttribute("xml:id", self.get_refid())
+ signed_cred.appendChild(cred)
+ append_sub(doc, cred, "type", "privilege")
+ append_sub(doc, cred, "serial", "8")
+ append_sub(doc, cred, "owner_gid", self.gidCaller.save_to_string())
+ append_sub(doc, cred, "owner_urn", self.gidCaller.get_urn())
+ append_sub(doc, cred, "target_gid", self.gidObject.save_to_string())
+ append_sub(doc, cred, "target_urn", self.gidObject.get_urn())
+ append_sub(doc, cred, "uuid", "")
+ if not self.expiration:
+ self.set_expiration(datetime.datetime.utcnow() + datetime.timedelta(seconds=DEFAULT_CREDENTIAL_LIFETIME))
+ self.expiration = self.expiration.replace(microsecond=0)
+ append_sub(doc, cred, "expires", self.expiration.isoformat())
+ privileges = doc.createElement("privileges")
+ cred.appendChild(privileges)
+
+ if self.privileges:
+ rights = self.get_privileges()
+ for right in rights.rights:
+ priv = doc.createElement("privilege")
+ append_sub(doc, priv, "name", right.kind)
+ append_sub(doc, priv, "can_delegate", str(right.delegate).lower())
+ privileges.appendChild(priv)
+
+ # Add the parent credential if it exists
+ if self.parent:
+ sdoc = parseString(self.parent.get_xml())
+ # 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 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")
+# 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):
+ attr = parentRoot.attributes.item(attrIx)
+ # returns the old attribute of same name that was
+ # on the credential
+ # 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.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")
+ p.appendChild(p_cred)
+ cred.appendChild(p)
+ # done handling parent credential
+
+ # Create the <signatures> tag
+ signatures = doc.createElement("signatures")
+ signed_cred.appendChild(signatures)
+
+ # Add any parent signatures
+ if self.parent:
+ for cur_cred in self.get_credential_list()[1:]:
+ sdoc = parseString(cur_cred.get_signature().get_xml())
+ ele = doc.importNode(sdoc.getElementsByTagName("Signature")[0], True)
+ signatures.appendChild(ele)
+
+ # Get the finished product
+ self.xml = doc.toxml()
+
+
+ def save_to_random_tmp_file(self):
+ fp, filename = mkstemp(suffix='cred', text=True)
+ fp = os.fdopen(fp, "w")
+ self.save_to_file(filename, save_parents=True, filep=fp)
+ return filename
+
+ def save_to_file(self, filename, save_parents=True, filep=None):
+ if not self.xml:
+ self.encode()
+ if filep:
+ f = filep
+ else:
+ f = open(filename, "w")
+ f.write(self.xml)
+ f.close()
+
+ def save_to_string(self, save_parents=True):
+ if not self.xml:
+ self.encode()
+ return self.xml
+
+ def get_refid(self):
+ if not self.refid:
+ self.refid = 'ref0'
+ return self.refid
+
+ def set_refid(self, rid):
+ self.refid = rid
+
+ ##
+ # Figure out what refids exist, and update this credential's id
+ # so that it doesn't clobber the others. Returns the refids of
+ # the parents.
+
+ def updateRefID(self):
+ if not self.parent:
+ self.set_refid('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
+ else:
+ next_cred = None
+
+
+ # Find a unique refid for this credential
+ rid = self.get_refid()
+ while rid in refs:
+ val = int(rid[3:])
+ rid = "ref%d" % (val + 1)
+
+ # Set the new refid
+ self.set_refid(rid)
+
+ # Return the set of parent credential ref ids
+ return refs
+
+ def get_xml(self):
+ if not self.xml:
+ self.encode()
+ return self.xml
+
+ ##
+ # Sign the XML file created by encode()
+ #
+ # WARNING:
+ # In general, a signed credential obtained externally should
+ # 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 sign(self):
+ if not self.issuer_privkey or not self.issuer_gid:
+ return
+ doc = parseString(self.get_xml())
+ sigs = doc.getElementsByTagName("signatures")[0]
+
+ # Create the signature template to be signed
+ signature = Signature()
+ signature.set_refid(self.get_refid())
+ sdoc = parseString(signature.get_xml())
+ sig_ele = doc.importNode(sdoc.getElementsByTagName("Signature")[0], True)
+ sigs.appendChild(sig_ele)
+
+ self.xml = doc.toxml()
+
+
+ # Split the issuer GID into multiple certificates if it's a chain
+ chain = GID(filename=self.issuer_gid)
+ gid_files = []
+ while chain:
+ gid_files.append(chain.save_to_random_tmp_file(False))
+ if chain.get_parent():
+ chain = chain.get_parent()
+ else:
+ chain = None
+
+
+ # Call out to xmlsec1 to sign it
+ ref = 'Sig_%s' % self.get_refid()
+ filename = self.save_to_random_tmp_file()
+ signed = os.popen('%s --sign --node-id "%s" --privkey-pem %s,%s %s' \
+ % (self.xmlsec_path, ref, self.issuer_privkey, ",".join(gid_files), filename)).read()
+ os.remove(filename)
+
+ for gid_file in gid_files:
+ os.remove(gid_file)
+
+ self.xml = signed
+
+ # This is no longer a legacy credential
+ if self.legacy:
+ self.legacy = None
+
+ # Update signatures
+ self.decode()
+
+
+ ##
+ # Retrieve the attributes of the credential from the XML.
+ # This is automatically called by the various get_* methods of
+ # this class and should not need to be called explicitly.
+
+ def decode(self):
+ if not self.xml:
+ return
+ 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:
+ creds = signed_cred[0].getElementsByTagName("credential")
+ signatures = signed_cred[0].getElementsByTagName("signatures")
+ if len(signatures) > 0:
+ sigs = signatures[0].getElementsByTagName("Signature")
+ else:
+ 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")))
+ self.gidCaller = GID(string=getTextNode(cred, "owner_gid"))
+ self.gidObject = GID(string=getTextNode(cred, "target_gid"))
+
+
+ # Process privileges
+ privs = cred.getElementsByTagName("privileges")[0]
+ rlist = Rights()
+ for priv in privs.getElementsByTagName("privilege"):
+ kind = getTextNode(priv, "name")
+ deleg = str2bool(getTextNode(priv, "can_delegate"))
+ if kind == '*':
+ # 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 = determine_rights(type, self.gidObject.get_urn())
+ for r in rl.rights:
+ r.delegate = deleg
+ rlist.add(r)
+ else:
+ rlist.add(Right(kind.strip(), deleg))
+ self.set_privileges(rlist)
+
+
+ # Is there a parent?
+ parent = cred.getElementsByTagName("parent")
+ if len(parent) > 0:
+ parent_doc = parent[0].getElementsByTagName("credential")[0]
+ parent_xml = parent_doc.toxml()
+ self.parent = Credential(string=parent_xml)
+ self.updateRefID()
+
+ # Assign the signatures to the credentials
+ for sig in sigs:
+ Sig = Signature(string=sig.toxml())
+
+ for cur_cred in self.get_credential_list():
+ if cur_cred.get_refid() == Sig.get_refid():
+ cur_cred.set_signature(Sig)
+
+
+ ##
+ # Verify
+ # trusted_certs: A list of trusted GID filenames (not GID objects!)
+ # Chaining is not supported within the GIDs by xmlsec1.
+ #
+ # trusted_certs_required: Should usually be true. Set False means an
+ # empty list of trusted_certs would still let this method pass.
+ # It just skips xmlsec1 verification et al. Only used by some utils
+ #
+ # Verify that:
+ # . All of the signatures are valid and that the issuers trace back
+ # to trusted roots (performed by xmlsec1)
+ # . The XML matches the credential schema
+ # . 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)
+ # . The privileges must be a subset of the parent credentials
+ # . The privileges must have "can_delegate" set for each delegated privilege
+ # . The target gid must be the same between child and parents
+ # . 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
+ #
+ # -- Verify does *NOT*
+ # . ensure that an xmlrpc client's gid matches a credential gid, that
+ # must be done elsewhere
+ #
+ # @param trusted_certs: The certificates of trusted CA certificates
+ def verify(self, trusted_certs=None, schema=None, trusted_certs_required=True):
+ if not self.xml:
+ self.decode()
+
+ # validate against RelaxNG schema
+ 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: %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 = []
+
+# trusted_cert_objects = [GID(filename=f) for f in trusted_certs]
+ trusted_cert_objects = []
+ ok_trusted_certs = []
+ # If caller explicitly passed in None that means skip cert chain validation.
+ # Strange and not typical
+ if trusted_certs is not None:
+ for f in trusted_certs:
+ try:
+ # Failures here include unreadable files
+ # or non PEM files
+ trusted_cert_objects.append(GID(filename=f))
+ 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
+
+ # Use legacy verification if this is a legacy credential
+ if self.legacy:
+ self.legacy.verify_chain(trusted_cert_objects)
+ if self.legacy.client_gid:
+ self.legacy.client_gid.verify_chain(trusted_cert_objects)
+ if self.legacy.object_gid:
+ self.legacy.object_gid.verify_chain(trusted_cert_objects)
+ return True
+
+ # make sure it is not expired
+ if self.get_expiration() < datetime.datetime.utcnow():
+ raise CredentialNotVerifiable("Credential %s expired at %s" % (self.get_summary_tostring(), self.expiration.isoformat()))
+
+ # Verify the signatures
+ filename = self.save_to_random_tmp_file()
+ if trusted_certs is not None:
+ 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
+ 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)
+
+ refs = []
+ refs.append("Sig_%s" % self.get_refid())
+
+ parentRefs = self.updateRefID()
+ for ref in parentRefs:
+ refs.append("Sig_%s" % ref)
+
+ for ref in refs:
+ # If caller explicitly passed in None that means skip xmlsec1 validation.
+ # Strange and not typical
+ if trusted_certs is None:
+ break
+
+# print "Doing %s --verify --node-id '%s' %s %s 2>&1" % \
+# (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()
+ if not verified.strip().startswith("OK"):
+ # xmlsec errors have a msg= which is the interesting bit.
+ mstart = verified.find("msg=")
+ msg = ""
+ if mstart > -1 and len(verified) > 4:
+ mstart = mstart + 4
+ mend = verified.find('\\', mstart)
+ msg = verified[mstart:mend]
+ 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, and is
+ # itself a valid GID
+ self.verify_issuer(trusted_cert_objects)
+ return True
+
+ ##
+ # Creates a list of the credential and its parents, with the root
+ # (original delegated credential) as the last item in the list
+ def get_credential_list(self):
+ cur_cred = self
+ list = []
+ while cur_cred:
+ list.append(cur_cred)
+ if cur_cred.parent:
+ cur_cred = cur_cred.parent
+ else:
+ cur_cred = None
+ return list
+
+ ##
+ # 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
+
+ # 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 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.find('authority') == 0):
+ #logger.debug('Cred signer is an authority')
+ # signer is an authority, see if target is in authority's domain
+ 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
+ # for that domain. Reasonable and probably correct.
+ # A looser model would also allow the signer to be an authority
+ # in my control framework - eg My CA or CH. Even if it is not
+ # the CH that issued these, eg, user credentials.
+
+ # Give up, credential does not pass issuer verification
+
+ 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()))
+
+
+ ##
+ # -- For Delegates (credentials with parents) verify that:
+ # . The privileges must be a subset of the parent credentials
+ # . The privileges must have "can_delegate" set for each delegated privilege
+ # . The target gid must be the same between child and parents
+ # . 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):
+ # 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 " % 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("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 %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 %s not signed by parent %s's caller" % (self.get_summary_tostring(), parent_cred.get_summary_tostring()))
+
+ # Recurse
+ if parent_cred.parent:
+ parent_cred.verify_parent(parent_cred.parent)
+
+
+ def delegate(self, delegee_gidfile, caller_keyfile, caller_gidfile):
+ """
+ Return a delegated copy of this credential, delegated to the
+ specified gid's user.
+ """
+ # get the gid of the object we are delegating
+ object_gid = self.get_gid_object()
+ object_hrn = object_gid.get_hrn()
+
+ # the hrn of the user who will be delegated to
+ delegee_gid = GID(filename=delegee_gidfile)
+ delegee_hrn = delegee_gid.get_hrn()
+
+ #user_key = Keypair(filename=keyfile)
+ #user_hrn = self.get_gid_caller().get_hrn()
+ subject_string = "%s delegated to %s" % (object_hrn, delegee_hrn)
+ dcred = Credential(subject=subject_string)
+ dcred.set_gid_caller(delegee_gid)
+ dcred.set_gid_object(object_gid)
+ dcred.set_parent(self)
+ dcred.set_expiration(self.get_expiration())
+ dcred.set_privileges(self.get_privileges())
+ dcred.get_privileges().delegate_all_privileges(True)
+ #dcred.set_issuer_keys(keyfile, delegee_gidfile)
+ dcred.set_issuer_keys(caller_keyfile, caller_gidfile)
+ dcred.encode()
+ dcred.sign()
+
+ return dcred
+
+ # only informative
+ def get_filename(self):
+ return getattr(self,'filename',None)
+
+ ##
+ # Dump the contents of a credential to stdout in human-readable format
+ #
+ # @param dump_parents If true, also dump the parent certificates
+ def dump (self, *args, **kwargs):
+ print self.dump_string(*args, **kwargs)
+
+
+ def dump_string(self, dump_parents=False):
+ result=""
+ 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()
+ gidCaller = self.get_gid_caller()
+ if gidCaller:
+ result += " gidCaller:\n"
+ result += gidCaller.dump_string(8, dump_parents)
+
+ if self.get_signature():
+ print " gidIssuer:"
+ self.get_signature().get_issuer_gid().dump(8, dump_parents)
+
+ gidObject = self.get_gid_object()
+ if gidObject:
+ result += " gidObject:\n"
+ result += gidObject.dump_string(8, dump_parents)
+
+ if self.parent and dump_parents:
+ result += "\nPARENT"
+ result += self.parent.dump_string(True)
+
+ return result
git://git.onelab.eu / sfa.git / blobdiff