# Credentials are signed XML files that assign a subject gid privileges to an object gid
##
-### $Id$
-### $URL$
+from __future__ import print_function
-import os
+import os, os.path
+import subprocess
+from types import StringTypes
import datetime
-from xml.dom.minidom import Document, parseString
+from StringIO import StringIO
from tempfile import mkstemp
-from sfa.trust.certificate import Keypair
-from sfa.trust.credential_legacy import CredentialLegacy
-from sfa.trust.rights import *
-from sfa.trust.gid import *
-from sfa.util.faults import *
+from xml.dom.minidom import Document, parseString
-from sfa.util.sfalogging import logger
-from dateutil.parser import parse
+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, 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
-# Two years, in seconds
-DEFAULT_CREDENTIAL_LIFETIME = 60 * 60 * 24 * 365 * 2
+# 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_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">
+ <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>
+ </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 ['yes','true','1']:
+ if str.lower() in ['true','1']:
return True
return False
self.gid = gid
def decode(self):
- doc = parseString(self.xml)
+ # 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, %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))
+ ## 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%s\n-----END CERTIFICATE-----" % 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_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.
+# 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 string If string!=None, load the credential from the string
# @param filename If filename!=None, load the credential from the file
# FIXME: create and subject are ignored!
- def __init__(self, create=False, subject=None, string=None, filename=None):
+ def __init__(self, create=False, subject=None, string=None, filename=None, cred=None):
self.gidCaller = None
self.gidObject = None
self.expiration = None
self.signature = None
self.xml = None
self.refid = None
- self.legacy = None
+ self.type = Credential.SFA_CREDENTIAL_TYPE
+ self.version = None
+
+ if cred:
+ if isinstance(cred, StringTypes):
+ 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']
- # 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)
+ # if this is a legacy credential, write error and bail out
+ if isinstance (str, StringTypes) and str.strip().startswith("-----"):
+ logger.error("Legacy credentials not supported any more - giving up with %s..."%str[:10])
+ return
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
+ # 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()
+ 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.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:
- # Default to two years
- self.set_lifetime(DEFAULT_CREDENTIAL_LIFETIME)
- else:
- self.set_lifetime(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
if not self.gidObject:
self.decode()
return self.gidObject
-
+
##
- # set the lifetime of this credential
- #
- # @param lifetime lifetime of credential
- # . if lifeTime is a datetime object, it is used for the expiration time
- # . if lifeTime is an integer value, it is considered the number of seconds
- # remaining before expiration
-
- def set_lifetime(self, lifeTime):
- if isinstance(lifeTime, int):
- self.expiration = datetime.timedelta(seconds=lifeTime) + datetime.datetime.utcnow()
+ # 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:
- self.expiration = lifeTime
+ logger.error ("unexpected input %s in Credential.set_expiration"%expiration)
##
- # get the lifetime of the credential (in datetime format)
+ # get the lifetime of the credential (always in datetime format)
- def get_lifetime(self):
+ 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 RightList object
+ # @param privs either a comma-separated list of privileges of a Rights object
def set_privileges(self, privs):
if isinstance(privs, str):
- self.privileges = RightList(string = privs)
+ self.privileges = Rights(string = privs)
else:
- self.privileges = privs
-
+ self.privileges = privs
##
- # return the privileges as a RightList object
+ # return the privileges as a Rights object
def get_privileges(self):
if not self.privileges:
# 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 <credential> bit
append_sub(doc, cred, "target_urn", self.gidObject.get_urn())
append_sub(doc, cred, "uuid", "")
if not self.expiration:
- self.set_lifetime(DEFAULT_CREDENTIAL_LIFETIME)
+ logger.debug("Creating credential valid for %s s"%DEFAULT_CREDENTIAL_LIFETIME)
+ 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())
+ 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)
# 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:\n - 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")
signatures.appendChild(ele)
# Get the finished product
- self.xml = doc.toxml()
+ self.xml = doc.toxml("utf-8")
def save_to_random_tmp_file(self):
# 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:
+ if not self.issuer_privkey:
+ logger.warn("Cannot sign credential (no private key)")
+ return
+ if not self.issuer_gid:
+ logger.warn("Cannot sign credential (no issuer gid)")
return
doc = parseString(self.get_xml())
sigs = doc.getElementsByTagName("signatures")[0]
sig_ele = doc.importNode(sdoc.getElementsByTagName("Signature")[0], True)
sigs.appendChild(sig_ele)
- self.xml = doc.toxml()
+ self.xml = doc.toxml("utf-8")
# Split the issuer GID into multiple certificates if it's a chain
# 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()
+ xmlsec1 = self.get_xmlsec1_path()
+ if not xmlsec1:
+ raise Exception("Could not locate required 'xmlsec1' program")
+ command = '%s --sign --node-id "%s" --privkey-pem %s,%s %s' \
+ % (xmlsec1, ref, self.issuer_privkey, ",".join(gid_files), filename)
+# print 'command',command
+ signed = os.popen(command).read()
os.remove(filename)
for gid_file in gid_files:
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
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:
- cred = signed_cred[0].getElementsByTagName("credential")[0]
+ creds = signed_cred[0].getElementsByTagName("credential")
signatures = signed_cred[0].getElementsByTagName("signatures")
if len(signatures) > 0:
sigs = signatures[0].getElementsByTagName("Signature")
else:
- cred = doc.getElementsByTagName("credential")[0]
+ creds = doc.getElementsByTagName("credential")
+ if creds is None or len(creds) == 0:
+ # malformed cred file
+ raise CredentialNotVerifiable("Malformed XML: No credential tag found")
+
+ # Just take the first cred if there are more than one
+ cred = creds[0]
self.set_refid(cred.getAttribute("xml:id"))
- self.set_lifetime(parse(getTextNode(cred, "expires")))
+ self.set_expiration(utcparse(getTextNode(cred, "expires")))
self.gidCaller = GID(string=getTextNode(cred, "owner_gid"))
- self.gidObject = GID(string=getTextNode(cred, "target_gid"))
+ self.gidObject = GID(string=getTextNode(cred, "target_gid"))
+ ## This code until the end of function rewritten by Aaron Helsinger
# Process privileges
- privs = cred.getElementsByTagName("privileges")[0]
- rlist = RightList()
- 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
- _ , type = urn_to_hrn(self.gidObject.get_urn())
- rl = rlist.determine_rights(type, self.gidObject.get_urn())
- for r in rl.rights:
- rlist.add(r)
- else:
- rlist.add(Right(kind.strip(), deleg))
+ 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)
parent = cred.getElementsByTagName("parent")
if len(parent) > 0:
parent_doc = parent[0].getElementsByTagName("credential")[0]
- parent_xml = parent_doc.toxml()
+ 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())
+ Sig = Signature(string=sig.toxml("utf-8"))
for cur_cred in self.get_credential_list():
if cur_cred.get_refid() == Sig.get_refid():
# 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
# . 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)
# must be done elsewhere
#
# @param trusted_certs: The certificates of trusted CA certificates
- def verify(self, trusted_certs):
+ def verify(self, trusted_certs=None, schema=None, trusted_certs_required=True):
if not self.xml:
- self.decode()
+ 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 = "%s: %s (line %s)" % (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 = []
- 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
-
+ # 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.error("Failed to load trusted cert from %s: %r"%( f, exc))
+ trusted_certs = ok_trusted_certs
+
# make sure it is not expired
- if self.get_lifetime() < datetime.datetime.utcnow():
- raise CredentialNotVerifiable("Credential expired at %s" % self.expiration.isoformat())
+ if self.get_expiration() < datetime.datetime.utcnow():
+ raise CredentialNotVerifiable("Credential %s expired at %s" % \
+ (self.pretty_cred(),
+ self.expiration.strftime(SFATIME_FORMAT)))
# Verify the signatures
filename = self.save_to_random_tmp_file()
- cert_args = " ".join(['--trusted-pem %s' % x for x in trusted_certs])
- # 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)
+ # 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())
refs.append("Sig_%s" % ref)
for ref in refs:
- 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"):
- raise CredentialNotVerifiable("xmlsec1 error verifying cert: " + verified)
+ # 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 %s' % 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 %s using Signature ID %s: %s" % \
+ (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
- self.verify_issuer()
+ # Make sure the issuer is the target's authority, and is
+ # itself a valid GID
+ self.verify_issuer(trusted_cert_objects)
return True
##
return list
##
- # Make sure the credential's target gid was signed by (or is the same) the entity that signed
- # the original credential or an authority over that namespace.
- def verify_issuer(self):
+ # Make sure the credential's target gid (a) was signed by or (b)
+ # is the same as the entity that signed the original credential,
+ # or (c) is an authority over the target's namespace.
+ # Also ensure that the credential issuer / signer itself has a valid
+ # GID signature chain (signed by an authority with namespace rights).
+ def verify_issuer(self, trusted_gids):
root_cred = self.get_credential_list()[-1]
root_target_gid = root_cred.get_gid_object()
+ if root_cred.get_signature() is None:
+ # malformed
+ raise CredentialNotVerifiable("Could not verify credential owned by %s for object %s. Cred has no signature" % (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
- root_target_gid_str = root_target_gid.save_to_string()
- root_cred_signer_str = root_cred_signer.save_to_string()
- if root_target_gid_str == root_cred_signer_str:
- # cred signer is target, return success
- return
+ # Case 2:
+ # Allow someone to sign credential about themeselves. Used?
+ # If not, remove this.
+ #root_target_gid_str = root_target_gid.save_to_string()
+ #root_cred_signer_str = root_cred_signer.save_to_string()
+ #if root_target_gid_str == root_cred_signer_str:
+ # # cred signer is target, return success
+ # return
+
+ # Case 3:
+
+ # root_cred_signer is not the target_gid
+ # So this is a different gid that we have not verified.
+ # xmlsec1 verified the cert chain on this already, but
+ # it hasn't verified that the gid meets the HRN namespace
+ # requirements.
+ # Below we'll ensure that it is an authority.
+ # But we haven't verified that it is _signed by_ an authority
+ # We also don't know if xmlsec1 requires that cert signers
+ # are marked as CAs.
+
+ # Note that if verify() gave us no trusted_gids then this
+ # call will fail. So skip it if we have no trusted_gids
+ if trusted_gids and len(trusted_gids) > 0:
+ root_cred_signer.verify_chain(trusted_gids)
+ else:
+ logger.debug("Cannot verify that cred signer is signed by a trusted authority. "
+ "No trusted gids. Skipping that check.")
- # See if it the signer is an authority over the domain of the target
+ # See if the signer is an authority over the domain of the target.
+ # There are multiple types of authority - accept them all here
# Maybe should be (hrn, type) = urn_to_hrn(root_cred_signer.get_urn())
root_cred_signer_type = root_cred_signer.get_type()
- if (root_cred_signer_type == 'authority'):
+ if root_cred_signer_type.find('authority') == 0:
#logger.debug('Cred signer is an authority')
# signer is an authority, see if target is in authority's domain
- hrn = root_cred_signer.get_hrn()
- if root_target_gid.get_hrn().startswith(hrn):
+ signerhrn = root_cred_signer.get_hrn()
+ if hrn_authfor_hrn(signerhrn, root_target_gid.get_hrn()):
return
# We've required that the credential be signed by an authority
# 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()))
-
+ 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:
# 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(
- self.parent.get_privileges().save_to_string() + " " +
- self.get_privileges().save_to_string())
+ 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():
- raise CredentialNotVerifiable("Target gid not equal between parent and child")
+ 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_lifetime() >= self.get_lifetime():
- raise CredentialNotVerifiable("Delegated credential expires after parent")
+ 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):
- raise CredentialNotVerifiable("Delegated credential not signed by parent caller")
+ 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_cred()))
+ 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_cred()))
+ 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_gid, keyfile):
+ 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 = self.get_hrn()
+ object_hrn = object_gid.get_hrn()
# the hrn of the user who will be delegated to
- if isinstance(delegee_gid, str):
- delegee_gid = GID(string=records[0]['gid'])
+ 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()
+
+ #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)
- privs = self.get_privileges()
+ 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_pubkey(object_gid.get_pubkey())
- dcred.set_issuer(user_key, user_hrn)
- dcred.set_parent(self)
+ #dcred.set_issuer_keys(keyfile, delegee_gidfile)
+ dcred.set_issuer_keys(caller_keyfile, caller_gidfile)
dcred.encode()
dcred.sign()
- return dcred
+ 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 = self.get_gid_caller().get_hrn()
+ issuer_hrn = self.get_signature().get_issuer_gid().get_hrn()
+ subject_hrn = self.get_gid_object().get_hrn()
+ # if we find that the caller_hrn is an immediate descendant of the issuer, then
+ # this seems to be a 'regular' credential
+ if 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=%s, issuer_hrn=%s, returning %s"
+ %(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, dump_parents=False):
- print "CREDENTIAL", self.get_subject()
-
- print " privs:", self.get_privileges().save_to_string()
-
- print " gidCaller:"
+ 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 %s\n" % self.pretty_subject()
+ filename=self.get_filename()
+ if filename: result += "Filename %s\n"%filename
+ privileges = self.get_privileges()
+ if privileges:
+ result += " privs: %s\n" % privileges.save_to_string()
+ else:
+ result += " privs: \n"
gidCaller = self.get_gid_caller()
if gidCaller:
- gidCaller.dump(8, dump_parents)
+ 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"
- print " gidObject:"
gidObject = self.get_gid_object()
if gidObject:
- gidObject.dump(8, dump_parents)
-
+ result += " gidObject:\n"
+ result += gidObject.dump_string(8, dump_parents)
if self.parent and dump_parents:
- print "PARENT",
- self.parent.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
git://git.onelab.eu / sfa.git / blobdiff