X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=sfa%2Ftrust%2Fcredential.py;h=301fefe439a212b53f43fe1be7db97511525bba0;hb=3147e8e089dd44e40b852cc121483189807ffa9b;hp=07f868066cda0fd6808fe746c98a8dd189a0a536;hpb=3d9943d1e5f993408b618cde29ff31b3585e5cef;p=sfa.git
diff --git a/sfa/trust/credential.py b/sfa/trust/credential.py
index 07f86806..301fefe4 100644
--- a/sfa/trust/credential.py
+++ b/sfa/trust/credential.py
@@ -1,1062 +1,1285 @@
-#----------------------------------------------------------------------
-# 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 = \
-'''
-
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-'''
-
-# 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 = \
-#'''
-#
-#
-#
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-#'''
-
-##
-# 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 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 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
+# ----------------------------------------------------------------------
+# 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
+##
+
+from __future__ import print_function
+
+import os
+import os.path
+import subprocess
+import datetime
+from tempfile import mkstemp
+from xml.dom.minidom import Document, parseString
+
+from sfa.util.py23 import PY3, StringType, StringIO
+
+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, SFATIME_FORMAT
+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
+
+HAVELXML = False
+try:
+ from lxml import etree
+ HAVELXML = True
+except:
+ pass
+
+
+# 31 days, 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_format = \
+ '''
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+'''
+
+##
+# 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):
+ # Helper function to pull characters off the front of a string if
+ # present
+ def remove_prefix(text, prefix):
+ if text and prefix and text.startswith(prefix):
+ return text[len(prefix):]
+ return text
+
+ try:
+ doc = parseString(self.xml)
+ except ExpatError as e:
+ logger.log_exc("Failed to parse credential, {}".format(self.xml))
+ raise
+ sig = doc.getElementsByTagName("Signature")[0]
+ # This code until the end of function rewritten by Aaron Helsinger
+ ref_id = remove_prefix(sig.getAttribute("xml:id").strip(), "Sig_")
+ # The xml:id tag is optional, and could be in a
+ # Reference xml:id or Reference UID sub element instead
+ if not ref_id or ref_id == '':
+ reference = sig.getElementsByTagName('Reference')[0]
+ ref_id = remove_prefix(
+ reference.getAttribute('xml:id').strip(), "Sig_")
+ if not ref_id or ref_id == '':
+ ref_id = remove_prefix(
+ reference.getAttribute('URI').strip(), "#")
+ self.set_refid(ref_id)
+ keyinfos = sig.getElementsByTagName("X509Data")
+ gids = None
+ for keyinfo in keyinfos:
+ certs = keyinfo.getElementsByTagName("X509Certificate")
+ for cert in certs:
+ if len(cert.childNodes) > 0:
+ szgid = cert.childNodes[0].nodeValue
+ szgid = szgid.strip()
+ szgid = "-----BEGIN CERTIFICATE-----\n"\
+ "{}\n-----END CERTIFICATE-----".format(
+ szgid)
+ if gids is None:
+ gids = szgid
+ else:
+ gids += "\n" + szgid
+ if gids is None:
+ raise CredentialNotVerifiable(
+ "Malformed XML: No certificate found in signature")
+ self.set_issuer_gid(GID(string=gids))
+
+ def encode(self):
+ self.xml = signature_format.format(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 (now
+# unsupported) 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.type != Credential.SFA_CREDENTIAL_TYPE:
+ continue
+ if tmp_cred.get_gid_caller().get_hrn() in caller_hrn_list:
+ caller_creds.append(cred)
+ except:
+ pass
+ return caller_creds
+
+
+class Credential(object):
+
+ SFA_CREDENTIAL_TYPE = "geni_sfa"
+
+ ##
+ # 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, cred=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.type = Credential.SFA_CREDENTIAL_TYPE
+ self.version = None
+
+ if cred:
+ if isinstance(cred, StringType):
+ string = cred
+ self.type = Credential.SFA_CREDENTIAL_TYPE
+ self.version = '3'
+ elif isinstance(cred, dict):
+ string = cred['geni_value']
+ self.type = cred['geni_type']
+ self.version = cred['geni_version']
+
+ if string or filename:
+ if string:
+ str = string
+ elif filename:
+ with open(filename) as infile:
+ str = infile.read()
+
+ # if this is a legacy credential, write error and bail out
+ if isinstance(str, StringType) and str.strip().startswith("-----"):
+ logger.error(
+ "Legacy credentials not supported any more "
+ "- giving up with {}..."
+ .format(str[:10]))
+ return
+ else:
+ self.xml = str
+ self.decode()
+ # not strictly necessary but won't hurt either
+ self.get_xmlsec1_path()
+
+ @staticmethod
+ def get_xmlsec1_path():
+ if not getattr(Credential, 'xmlsec1_path', None):
+ # Find a xmlsec1 binary path
+ Credential.xmlsec1_path = ''
+ paths = ['/usr/bin', '/usr/local/bin',
+ '/bin', '/opt/bin', '/opt/local/bin']
+ try:
+ paths += os.getenv('PATH').split(':')
+ except:
+ pass
+ for path in paths:
+ xmlsec1 = os.path.join(path, 'xmlsec1')
+ if os.path.isfile(xmlsec1):
+ Credential.xmlsec1_path = xmlsec1
+ break
+ if not Credential.xmlsec1_path:
+ logger.error(
+ "Could not locate required binary 'xmlsec1' -"
+ "SFA will be unable to sign stuff !!")
+ return Credential.xmlsec1_path
+
+ def get_subject(self):
+ if not self.gidObject:
+ self.decode()
+ return self.gidObject.get_subject()
+
+ def pretty_subject(self):
+ subject = ""
+ if not self.gidObject:
+ self.decode()
+ if self.gidObject:
+ subject = self.gidObject.pretty_cert()
+ return subject
+
+ # sounds like this should be __repr__ instead ??
+ def pretty_cred(self):
+ if not self.gidObject:
+ self.decode()
+ obj = self.gidObject.pretty_cert()
+ caller = self.gidCaller.pretty_cert()
+ exp = self.get_expiration()
+ # Summarize the rights too? The issuer?
+ return "[Cred. for {caller} rights on {obj} until {exp} ]"\
+ .format(**locals())
+
+ def get_signature(self):
+ if not self.signature:
+ self.decode()
+ return self.signature
+
+ def set_signature(self, sig):
+ self.signature = sig
+
+ ##
+ # 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):
+ expiration_datetime = utcparse(expiration)
+ if expiration_datetime is not None:
+ self.expiration = expiration_datetime
+ else:
+ logger.error(
+ "unexpected input {} in Credential.set_expiration"
+ .format(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
+
+ ##
+ # 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")
+ # FIXME: See v2 schema at
+ # www.geni.net/resources/credential/2/credential.xsd
+ 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 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:
+ logger.debug("Creating credential valid for {} s".format(
+ DEFAULT_CREDENTIAL_LIFETIME))
+ self.set_expiration(datetime.datetime.utcnow(
+ ) + datetime.timedelta(seconds=DEFAULT_CREDENTIAL_LIFETIME))
+ self.expiration = self.expiration.replace(microsecond=0)
+ if self.expiration.tzinfo is not None \
+ and self.expiration.tzinfo.utcoffset(self.expiration) is not None:
+ # TZ aware. Make sure it is UTC - by Aaron Helsinger
+ self.expiration = self.expiration.astimezone(tz.tzutc())
+ append_sub(doc, cred, "expires",
+ self.expiration.strftime(SFATIME_FORMAT))
+ 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 PL add 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 {} to {} over {}:\n"
+ "- Replaced attribute {} value '{}' with '{}'"\
+ .format(self.parent.gidCaller.get_urn(),
+ self.gidCaller.get_urn(),
+ self.gidObject.get_urn(),
+ oldAttr.name, oldAttr.value, attr.value)
+ logger.warning(msg)
+ # raise CredentialNotVerifiable(
+ # "Can't encode new valid delegated credential: {}"
+ # .format(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 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("utf-8")
+
+ 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")
+ if PY3 and isinstance(self.xml, bytes):
+ self.xml = self.xml.decode()
+ f.write(self.xml)
+ f.close()
+
+ def save_to_string(self, save_parents=True):
+ if not self.xml:
+ self.encode()
+ if PY3 and isinstance(self.xml, bytes):
+ self.xml = self.xml.decode()
+ 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{}".format(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:
+ logger.warning("Cannot sign credential (no private key)")
+ return
+ if not self.issuer_gid:
+ logger.warning("Cannot sign credential (no 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("utf-8")
+
+ # 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_{}'.format(self.get_refid())
+ filename = self.save_to_random_tmp_file()
+ xmlsec1 = self.get_xmlsec1_path()
+ if not xmlsec1:
+ raise Exception("Could not locate required 'xmlsec1' program")
+ command = '{} --sign --node-id "{}" --privkey-pem {},{} {}' \
+ .format(xmlsec1, ref, self.issuer_privkey,
+ ",".join(gid_files), filename)
+ signed = os.popen(command).read()
+ os.remove(filename)
+
+ for gid_file in gid_files:
+ os.remove(gid_file)
+
+ self.xml = signed
+
+ # 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 = None
+ try:
+ doc = parseString(self.xml)
+ except ExpatError as e:
+ raise CredentialNotVerifiable("Malformed credential")
+ doc = parseString(self.xml)
+ sigs = []
+ signed_cred = doc.getElementsByTagName("signed-credential")
+
+ # Is this a signed-cred or just a cred?
+ if len(signed_cred) > 0:
+ 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"))
+
+ # This code until the end of function rewritten by Aaron Helsinger
+ # Process privileges
+ rlist = Rights()
+ priv_nodes = cred.getElementsByTagName("privileges")
+ if len(priv_nodes) > 0:
+ privs = priv_nodes[0]
+ 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("utf-8")
+ if parent_xml is None or parent_xml.strip() == "":
+ raise CredentialNotVerifiable(
+ "Malformed XML: Had parent tag but it is empty")
+ self.parent = Credential(string=parent_xml)
+ self.updateRefID()
+
+ # Assign the signatures to the credentials
+ for sig in sigs:
+ Sig = Signature(string=sig.toxml("utf-8"))
+
+ 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:
+ 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 = "{}: {} (line {})"\
+ .format(self.pretty_cred(),
+ 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 as exc:
+ logger.exception(
+ "Failed to load trusted cert from {}".format(f))
+ trusted_certs = ok_trusted_certs
+
+ # make sure it is not expired
+ if self.get_expiration() < datetime.datetime.utcnow():
+ raise CredentialNotVerifiable(
+ "Credential {} expired at {}"
+ .format(self.pretty_cred(),
+ self.expiration.strftime(SFATIME_FORMAT)))
+
+ # Verify the signatures
+ filename = self.save_to_random_tmp_file()
+
+ # If caller explicitly passed in None that means
+ # skip cert chain validation. Strange and not typical
+ if trusted_certs is not None:
+ # Verify the caller and object gids of this cred and of its parents
+ for cur_cred in self.get_credential_list():
+ # check both the caller and the subject
+ for gid in (cur_cred.get_gid_object(),
+ cur_cred.get_gid_caller()):
+ logger.debug("Credential.verify: verifying chain {}"
+ .format(gid.pretty_cert()))
+ logger.debug("Credential.verify: against trusted {}"
+ .format(" ".join(trusted_certs)))
+ gid.verify_chain(trusted_cert_objects)
+
+ refs = []
+ refs.append("Sig_{}".format(self.get_refid()))
+
+ parentRefs = self.updateRefID()
+ for ref in parentRefs:
+ refs.append("Sig_{}".format(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
+
+ # Thierry - jan 2015
+ # up to fedora20 we used os.popen and checked
+ # that the output begins with OK; turns out, with fedora21,
+ # there is extra input before this 'OK' thing
+ # looks like we're better off just using the exit code
+ # that's what it is made for
+ # cert_args = " ".join(['--trusted-pem {}'.format(x) for x in trusted_certs])
+ # command = '{} --verify --node-id "{}" {} {} 2>&1'.\
+ # format(self.xmlsec_path, ref, cert_args, filename)
+ xmlsec1 = self.get_xmlsec1_path()
+ if not xmlsec1:
+ raise Exception("Could not locate required 'xmlsec1' program")
+ command = [xmlsec1, '--verify', '--node-id', ref]
+ for trusted in trusted_certs:
+ command += ["--trusted-pem", trusted]
+ command += [filename]
+ logger.debug("Running " + " ".join(command))
+ try:
+ verified = subprocess.check_output(
+ command, stderr=subprocess.STDOUT)
+ logger.debug("xmlsec command returned {}".format(verified))
+ if "OK\n" not in verified:
+ logger.warning(
+ "WARNING: xmlsec1 seemed to return fine but without a OK in its output")
+ except subprocess.CalledProcessError as e:
+ verified = e.output
+ # 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]
+ logger.warning(
+ "Credential.verify - failed - xmlsec1 returned {}"
+ .format(verified.strip()))
+ raise CredentialNotVerifiable(
+ "xmlsec1 error verifying cred {} using Signature ID {}: {}"
+ .format(self.pretty_cred(), ref, msg))
+ 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()
+ if root_cred.get_signature() is None:
+ # malformed
+ raise CredentialNotVerifiable(
+ "Could not verify credential owned by {} for object {}. "
+ "Cred has no signature"
+ .format(self.gidCaller.get_urn(), self.gidObject.get_urn()))
+
+ 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(
+ "Cannot verify that cred signer is signed by a trusted authority. "
+ "No trusted gids. 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 {} for object {}. "
+ "Cred signer {} not the trusted authority for Cred target {}"
+ .format(self.gidCaller.get_hrn(), self.gidObject.get_hrn(),
+ 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()):
+ message = (
+ "Parent cred {} (ref {}) rights {} "
+ " not superset of delegated cred {} (ref {}) rights {}"
+ .format(parent_cred.pretty_cred(), parent_cred.get_refid(),
+ parent_cred.get_privileges().pretty_rights(),
+ self.pretty_cred(), self.get_refid(),
+ self.get_privileges().pretty_rights()))
+ logger.error(message)
+ logger.error("parent details {}".format(
+ parent_cred.get_privileges().save_to_string()))
+ logger.error("self details {}".format(
+ self.get_privileges().save_to_string()))
+ raise ChildRightsNotSubsetOfParent(message)
+
+ # 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():
+ message = (
+ "Delegated cred {}: Target gid not equal between parent and child. Parent {}"
+ .format(self.pretty_cred(), parent_cred.pretty_cred()))
+ logger.error(message)
+ logger.error("parent details {}".format(
+ parent_cred.save_to_string()))
+ logger.error("self details {}".format(self.save_to_string()))
+ raise CredentialNotVerifiable(message)
+
+ # make sure my expiry time is <= my parent's
+ if not parent_cred.get_expiration() >= self.get_expiration():
+ raise CredentialNotVerifiable(
+ "Delegated credential {} expires after parent {}"
+ .format(self.pretty_cred(), parent_cred.pretty_cred()))
+
+ # 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):
+ message = "Delegated credential {} not signed by parent {}'s caller"\
+ .format(self.pretty_cred(), parent_cred.pretty_cred())
+ logger.error(message)
+ logger.error("compare1 parent {}".format(
+ parent_cred.get_gid_caller().pretty_cert()))
+ logger.error("compare1 parent details {}".format(
+ parent_cred.get_gid_caller().save_to_string()))
+ logger.error("compare2 self {}".format(
+ self.get_signature().get_issuer_gid().pretty_crert()))
+ logger.error("compare2 self details {}".format(
+ self.get_signature().get_issuer_gid().save_to_string()))
+ raise CredentialNotVerifiable(message)
+
+ # 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 = "{} delegated to {}".format(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)
+
+ def actual_caller_hrn(self):
+ """
+ a helper method used by some API calls like e.g. Allocate
+ to try and find out who really is the original caller
+
+ This admittedly is a bit of a hack, please USE IN LAST RESORT
+
+ This code uses a heuristic to identify a delegated credential
+
+ A first known restriction if for traffic that gets through a
+ slice manager in this case the hrn reported is the one from
+ the last SM in the call graph which is not at all what is
+ meant here
+ """
+
+ caller_hrn, caller_type = urn_to_hrn(self.get_gid_caller().get_urn())
+ issuer_hrn, issuer_type = urn_to_hrn(
+ self.get_signature().get_issuer_gid().get_urn())
+ subject_hrn = self.get_gid_object().get_hrn()
+ # if the caller is a user and the issuer is not
+ # it's probably the former
+ if caller_type == "user" and issuer_type != "user":
+ actual_caller_hrn = caller_hrn
+ # if we find that the caller_hrn is an immediate descendant
+ # of the issuer, then this seems to be a 'regular' credential
+ elif caller_hrn.startswith(issuer_hrn):
+ actual_caller_hrn = caller_hrn
+ # else this looks like a delegated credential, and the real caller is
+ # the issuer
+ else:
+ actual_caller_hrn = issuer_hrn
+ logger.info(
+ "actual_caller_hrn: caller_hrn={}, issuer_hrn={}, returning {}"
+ .format(caller_hrn, issuer_hrn, actual_caller_hrn))
+ return actual_caller_hrn
+
+ ##
+ # 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))
+
+ # SFA code ignores show_xml and disables printing the cred xml
+ def dump_string(self, dump_parents=False, show_xml=False):
+ result = ""
+ result += "CREDENTIAL {}\n".format(self.pretty_subject())
+ filename = self.get_filename()
+ if filename:
+ result += "Filename {}\n".format(filename)
+ privileges = self.get_privileges()
+ if privileges:
+ result += " privs: {}\n".format(privileges.save_to_string())
+ else:
+ result += " privs: \n"
+ gidCaller = self.get_gid_caller()
+ if gidCaller:
+ result += " gidCaller:\n"
+ result += gidCaller.dump_string(8, dump_parents)
+
+ if self.get_signature():
+ result += " gidIssuer:\n"
+ result += self.get_signature().get_issuer_gid()\
+ .dump_string(8, dump_parents)
+
+ if self.expiration:
+ result += " expiration: " + \
+ self.expiration.strftime(SFATIME_FORMAT) + "\n"
+
+ 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)
+
+ if show_xml and HAVELXML:
+ try:
+ tree = etree.parse(StringIO(self.xml))
+ aside = etree.tostring(tree, pretty_print=True)
+ result += "\nXML:\n\n"
+ result += aside
+ result += "\nEnd XML\n"
+ except:
+ import traceback
+ print("exc. Credential.dump_string / XML")
+ traceback.print_exc()
+
+ return result