-#----------------------------------------------------------------------
-# 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
+#----------------------------------------------------------------------\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
git://git.onelab.eu / sfa.git / commitdiff