1 #----------------------------------------------------------------------
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2 # Copyright (c) 2008 Board of Trustees, Princeton University
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4 # Permission is hereby granted, free of charge, to any person obtaining
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5 # a copy of this software and/or hardware specification (the "Work") to
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6 # deal in the Work without restriction, including without limitation the
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7 # rights to use, copy, modify, merge, publish, distribute, sublicense,
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8 # and/or sell copies of the Work, and to permit persons to whom the Work
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9 # is furnished to do so, subject to the following conditions:
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11 # The above copyright notice and this permission notice shall be
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12 # included in all copies or substantial portions of the Work.
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14 # THE WORK IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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15 # OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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16 # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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17 # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
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18 # HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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19 # WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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20 # OUT OF OR IN CONNECTION WITH THE WORK OR THE USE OR OTHER DEALINGS
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22 #----------------------------------------------------------------------
\r
24 # Implements SFA Credentials
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26 # Credentials are signed XML files that assign a subject gid privileges to an object gid
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30 from types import StringTypes
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32 from StringIO import StringIO
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33 from tempfile import mkstemp
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34 from xml.dom.minidom import Document, parseString
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38 from lxml import etree
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43 from sfa.util.faults import *
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44 from sfa.util.sfalogging import logger
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45 from sfa.util.sfatime import utcparse
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46 from sfa.trust.certificate import Keypair
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47 from sfa.trust.credential_legacy import CredentialLegacy
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48 from sfa.trust.rights import Right, Rights, determine_rights
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49 from sfa.trust.gid import GID
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50 from sfa.util.xrn import urn_to_hrn, hrn_authfor_hrn
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52 # 2 weeks, in seconds
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53 DEFAULT_CREDENTIAL_LIFETIME = 86400 * 14
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57 # . make privs match between PG and PL
\r
58 # . Need to add support for other types of credentials, e.g. tickets
\r
59 # . add namespaces to signed-credential element?
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61 signature_template = \
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63 <Signature xml:id="Sig_%s" xmlns="http://www.w3.org/2000/09/xmldsig#">
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65 <CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
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66 <SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/>
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67 <Reference URI="#%s">
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69 <Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature" />
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71 <DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>
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72 <DigestValue></DigestValue>
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87 # PG formats the template (whitespace) slightly differently.
\r
88 # Note that they don't include the xmlns in the template, but add it later.
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89 # Otherwise the two are equivalent.
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90 #signature_template_as_in_pg = \
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92 #<Signature xml:id="Sig_%s" >
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94 # <CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
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95 # <SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/>
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96 # <Reference URI="#%s">
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98 # <Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature" />
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100 # <DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>
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101 # <DigestValue></DigestValue>
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104 # <SignatureValue />
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107 # <X509SubjectName/>
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108 # <X509IssuerSerial/>
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109 # <X509Certificate/>
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117 # Convert a string into a bool
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118 # used to convert an xsd:boolean to a Python boolean
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120 if str.lower() in ['true','1']:
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126 # Utility function to get the text of an XML element
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128 def getTextNode(element, subele):
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129 sub = element.getElementsByTagName(subele)[0]
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130 if len(sub.childNodes) > 0:
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131 return sub.childNodes[0].nodeValue
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136 # Utility function to set the text of an XML element
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137 # It creates the element, adds the text to it,
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138 # and then appends it to the parent.
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140 def append_sub(doc, parent, element, text):
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141 ele = doc.createElement(element)
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142 ele.appendChild(doc.createTextNode(text))
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143 parent.appendChild(ele)
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146 # Signature contains information about an xmlsec1 signature
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147 # for a signed-credential
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150 class Signature(object):
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152 def __init__(self, string=None):
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154 self.issuer_gid = None
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161 def get_refid(self):
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171 def set_refid(self, id):
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174 def get_issuer_gid(self):
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179 def set_issuer_gid(self, gid):
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183 doc = parseString(self.xml)
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184 sig = doc.getElementsByTagName("Signature")[0]
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185 self.set_refid(sig.getAttribute("xml:id").strip("Sig_"))
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186 keyinfo = sig.getElementsByTagName("X509Data")[0]
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187 szgid = getTextNode(keyinfo, "X509Certificate")
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188 szgid = "-----BEGIN CERTIFICATE-----\n%s\n-----END CERTIFICATE-----" % szgid
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189 self.set_issuer_gid(GID(string=szgid))
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192 self.xml = signature_template % (self.get_refid(), self.get_refid())
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196 # A credential provides a caller gid with privileges to an object gid.
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197 # A signed credential is signed by the object's authority.
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199 # Credentials are encoded in one of two ways. The legacy style places
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200 # it in the subjectAltName of an X509 certificate. The new credentials
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201 # are placed in signed XML.
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204 # In general, a signed credential obtained externally should
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205 # not be changed else the signature is no longer valid. So, once
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206 # you have loaded an existing signed credential, do not call encode() or sign() on it.
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208 def filter_creds_by_caller(creds, caller_hrn):
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210 Returns a list of creds who's gid caller matches the
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211 specified caller hrn
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213 if not isinstance(creds, list): creds = [creds]
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217 tmp_cred = Credential(string=cred)
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218 if tmp_cred.get_gid_caller().get_hrn() == caller_hrn:
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219 caller_creds.append(cred)
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221 return caller_creds
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223 class Credential(object):
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226 # Create a Credential object
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228 # @param create If true, create a blank x509 certificate
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229 # @param subject If subject!=None, create an x509 cert with the subject name
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230 # @param string If string!=None, load the credential from the string
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231 # @param filename If filename!=None, load the credential from the file
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232 # FIXME: create and subject are ignored!
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233 def __init__(self, create=False, subject=None, string=None, filename=None):
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234 self.gidCaller = None
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235 self.gidObject = None
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236 self.expiration = None
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237 self.privileges = None
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238 self.issuer_privkey = None
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239 self.issuer_gid = None
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240 self.issuer_pubkey = None
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242 self.signature = None
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247 # Check if this is a legacy credential, translate it if so
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248 if string or filename:
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252 str = file(filename).read()
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254 if str.strip().startswith("-----"):
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255 self.legacy = CredentialLegacy(False,string=str)
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256 self.translate_legacy(str)
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261 # Find an xmlsec1 path
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262 self.xmlsec_path = ''
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263 paths = ['/usr/bin','/usr/local/bin','/bin','/opt/bin','/opt/local/bin']
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265 if os.path.isfile(path + '/' + 'xmlsec1'):
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266 self.xmlsec_path = path + '/' + 'xmlsec1'
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269 def get_subject(self):
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270 if not self.gidObject:
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272 return self.gidObject.get_printable_subject()
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274 def get_summary_tostring(self):
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275 if not self.gidObject:
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277 obj = self.gidObject.get_printable_subject()
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278 caller = self.gidCaller.get_printable_subject()
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279 exp = self.get_expiration()
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280 # Summarize the rights too? The issuer?
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281 return "[ Grant %s rights on %s until %s ]" % (caller, obj, exp)
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283 def get_signature(self):
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284 if not self.signature:
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286 return self.signature
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288 def set_signature(self, sig):
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289 self.signature = sig
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293 # Translate a legacy credential into a new one
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295 # @param String of the legacy credential
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297 def translate_legacy(self, str):
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298 legacy = CredentialLegacy(False,string=str)
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299 self.gidCaller = legacy.get_gid_caller()
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300 self.gidObject = legacy.get_gid_object()
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301 lifetime = legacy.get_lifetime()
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303 self.set_expiration(datetime.datetime.utcnow() + datetime.timedelta(seconds=DEFAULT_CREDENTIAL_LIFETIME))
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305 self.set_expiration(int(lifetime))
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306 self.lifeTime = legacy.get_lifetime()
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307 self.set_privileges(legacy.get_privileges())
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308 self.get_privileges().delegate_all_privileges(legacy.get_delegate())
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311 # Need the issuer's private key and name
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312 # @param key Keypair object containing the private key of the issuer
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313 # @param gid GID of the issuing authority
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315 def set_issuer_keys(self, privkey, gid):
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316 self.issuer_privkey = privkey
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317 self.issuer_gid = gid
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321 # Set this credential's parent
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322 def set_parent(self, cred):
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327 # set the GID of the caller
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329 # @param gid GID object of the caller
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331 def set_gid_caller(self, gid):
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332 self.gidCaller = gid
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333 # gid origin caller is the caller's gid by default
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334 self.gidOriginCaller = gid
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337 # get the GID of the object
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339 def get_gid_caller(self):
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340 if not self.gidCaller:
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342 return self.gidCaller
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345 # set the GID of the object
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347 # @param gid GID object of the object
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349 def set_gid_object(self, gid):
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350 self.gidObject = gid
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353 # get the GID of the object
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355 def get_gid_object(self):
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356 if not self.gidObject:
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358 return self.gidObject
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363 # Expiration: an absolute UTC time of expiration (as either an int or string or datetime)
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365 def set_expiration(self, expiration):
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366 if isinstance(expiration, (int, float)):
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367 self.expiration = datetime.datetime.fromtimestamp(expiration)
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368 elif isinstance (expiration, datetime.datetime):
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369 self.expiration = expiration
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370 elif isinstance (expiration, StringTypes):
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371 self.expiration = utcparse (expiration)
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373 logger.error ("unexpected input type in Credential.set_expiration")
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377 # get the lifetime of the credential (always in datetime format)
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379 def get_expiration(self):
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380 if not self.expiration:
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382 # at this point self.expiration is normalized as a datetime - DON'T call utcparse again
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383 return self.expiration
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387 def get_lifetime(self):
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388 return self.get_expiration()
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391 # set the privileges
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393 # @param privs either a comma-separated list of privileges of a Rights object
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395 def set_privileges(self, privs):
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396 if isinstance(privs, str):
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397 self.privileges = Rights(string = privs)
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399 self.privileges = privs
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403 # return the privileges as a Rights object
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405 def get_privileges(self):
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406 if not self.privileges:
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408 return self.privileges
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411 # determine whether the credential allows a particular operation to be
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414 # @param op_name string specifying name of operation ("lookup", "update", etc)
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416 def can_perform(self, op_name):
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417 rights = self.get_privileges()
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422 return rights.can_perform(op_name)
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426 # Encode the attributes of the credential into an XML string
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427 # This should be done immediately before signing the credential.
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429 # In general, a signed credential obtained externally should
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430 # not be changed else the signature is no longer valid. So, once
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431 # you have loaded an existing signed credential, do not call encode() or sign() on it.
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434 # Create the XML document
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436 signed_cred = doc.createElement("signed-credential")
\r
438 # Declare namespaces
\r
439 # Note that credential/policy.xsd are really the PG schemas
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440 # in a PL namespace.
\r
441 # Note that delegation of credentials between the 2 only really works
\r
442 # cause those schemas are identical.
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443 # Also note these PG schemas talk about PG tickets and CM policies.
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444 signed_cred.setAttribute("xmlns:xsi", "http://www.w3.org/2001/XMLSchema-instance")
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445 signed_cred.setAttribute("xsi:noNamespaceSchemaLocation", "http://www.planet-lab.org/resources/sfa/credential.xsd")
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446 signed_cred.setAttribute("xsi:schemaLocation", "http://www.planet-lab.org/resources/sfa/ext/policy/1 http://www.planet-lab.org/resources/sfa/ext/policy/1/policy.xsd")
\r
448 # PG says for those last 2:
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449 # signed_cred.setAttribute("xsi:noNamespaceSchemaLocation", "http://www.protogeni.net/resources/credential/credential.xsd")
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450 # 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")
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452 doc.appendChild(signed_cred)
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454 # Fill in the <credential> bit
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455 cred = doc.createElement("credential")
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456 cred.setAttribute("xml:id", self.get_refid())
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457 signed_cred.appendChild(cred)
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458 append_sub(doc, cred, "type", "privilege")
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459 append_sub(doc, cred, "serial", "8")
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460 append_sub(doc, cred, "owner_gid", self.gidCaller.save_to_string())
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461 append_sub(doc, cred, "owner_urn", self.gidCaller.get_urn())
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462 append_sub(doc, cred, "target_gid", self.gidObject.save_to_string())
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463 append_sub(doc, cred, "target_urn", self.gidObject.get_urn())
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464 append_sub(doc, cred, "uuid", "")
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465 if not self.expiration:
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466 self.set_expiration(datetime.datetime.utcnow() + datetime.timedelta(seconds=DEFAULT_CREDENTIAL_LIFETIME))
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467 self.expiration = self.expiration.replace(microsecond=0)
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468 append_sub(doc, cred, "expires", self.expiration.isoformat())
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469 privileges = doc.createElement("privileges")
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470 cred.appendChild(privileges)
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472 if self.privileges:
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473 rights = self.get_privileges()
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474 for right in rights.rights:
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475 priv = doc.createElement("privilege")
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476 append_sub(doc, priv, "name", right.kind)
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477 append_sub(doc, priv, "can_delegate", str(right.delegate).lower())
\r
478 privileges.appendChild(priv)
\r
480 # Add the parent credential if it exists
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482 sdoc = parseString(self.parent.get_xml())
\r
483 # If the root node is a signed-credential (it should be), then
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484 # get all its attributes and attach those to our signed_cred
\r
486 # Specifically, PG and PLadd attributes for namespaces (which is reasonable),
\r
487 # and we need to include those again here or else their signature
\r
488 # no longer matches on the credential.
\r
489 # We expect three of these, but here we copy them all:
\r
490 # signed_cred.setAttribute("xmlns:xsi", "http://www.w3.org/2001/XMLSchema-instance")
\r
491 # and from PG (PL is equivalent, as shown above):
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492 # signed_cred.setAttribute("xsi:noNamespaceSchemaLocation", "http://www.protogeni.net/resources/credential/credential.xsd")
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493 # signed_cred.setAttribute("xsi:schemaLocation", "http://www.protogeni.net/resources/credential/ext/policy/1 http://www.protogeni.net/resources/credential/ext/policy/1/policy.xsd")
\r
496 # PL now also declares these, with different URLs, so
\r
497 # the code notices those attributes already existed with
\r
498 # different values, and complains.
\r
499 # This happens regularly on delegation now that PG and
\r
500 # PL both declare the namespace with different URLs.
\r
501 # If the content ever differs this is a problem,
\r
502 # but for now it works - different URLs (values in the attributes)
\r
503 # but the same actual schema, so using the PG schema
\r
504 # on delegated-to-PL credentials works fine.
\r
506 # Note: you could also not copy attributes
\r
507 # which already exist. It appears that both PG and PL
\r
508 # will actually validate a slicecred with a parent
\r
509 # signed using PG namespaces and a child signed with PL
\r
510 # namespaces over the whole thing. But I don't know
\r
511 # if that is a bug in xmlsec1, an accident since
\r
512 # the contents of the schemas are the same,
\r
513 # or something else, but it seems odd. And this works.
\r
514 parentRoot = sdoc.documentElement
\r
515 if parentRoot.tagName == "signed-credential" and parentRoot.hasAttributes():
\r
516 for attrIx in range(0, parentRoot.attributes.length):
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517 attr = parentRoot.attributes.item(attrIx)
\r
518 # returns the old attribute of same name that was
\r
519 # on the credential
\r
520 # Below throws InUse exception if we forgot to clone the attribute first
\r
521 oldAttr = signed_cred.setAttributeNode(attr.cloneNode(True))
\r
522 if oldAttr and oldAttr.value != attr.value:
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523 msg = "Delegating cred from owner %s to %s over %s replaced attribute %s value '%s' with '%s'" % (self.parent.gidCaller.get_urn(), self.gidCaller.get_urn(), self.gidObject.get_urn(), oldAttr.name, oldAttr.value, attr.value)
\r
525 #raise CredentialNotVerifiable("Can't encode new valid delegated credential: %s" % msg)
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527 p_cred = doc.importNode(sdoc.getElementsByTagName("credential")[0], True)
\r
528 p = doc.createElement("parent")
\r
529 p.appendChild(p_cred)
\r
530 cred.appendChild(p)
\r
531 # done handling parent credential
\r
533 # Create the <signatures> tag
\r
534 signatures = doc.createElement("signatures")
\r
535 signed_cred.appendChild(signatures)
\r
537 # Add any parent signatures
\r
539 for cur_cred in self.get_credential_list()[1:]:
\r
540 sdoc = parseString(cur_cred.get_signature().get_xml())
\r
541 ele = doc.importNode(sdoc.getElementsByTagName("Signature")[0], True)
\r
542 signatures.appendChild(ele)
\r
544 # Get the finished product
\r
545 self.xml = doc.toxml()
\r
548 def save_to_random_tmp_file(self):
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549 fp, filename = mkstemp(suffix='cred', text=True)
\r
550 fp = os.fdopen(fp, "w")
\r
551 self.save_to_file(filename, save_parents=True, filep=fp)
\r
554 def save_to_file(self, filename, save_parents=True, filep=None):
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560 f = open(filename, "w")
\r
564 def save_to_string(self, save_parents=True):
\r
569 def get_refid(self):
\r
571 self.refid = 'ref0'
\r
574 def set_refid(self, rid):
\r
578 # Figure out what refids exist, and update this credential's id
\r
579 # so that it doesn't clobber the others. Returns the refids of
\r
582 def updateRefID(self):
\r
583 if not self.parent:
\r
584 self.set_refid('ref0')
\r
589 next_cred = self.parent
\r
591 refs.append(next_cred.get_refid())
\r
592 if next_cred.parent:
\r
593 next_cred = next_cred.parent
\r
598 # Find a unique refid for this credential
\r
599 rid = self.get_refid()
\r
602 rid = "ref%d" % (val + 1)
\r
604 # Set the new refid
\r
605 self.set_refid(rid)
\r
607 # Return the set of parent credential ref ids
\r
616 # Sign the XML file created by encode()
\r
619 # In general, a signed credential obtained externally should
\r
620 # not be changed else the signature is no longer valid. So, once
\r
621 # you have loaded an existing signed credential, do not call encode() or sign() on it.
\r
624 if not self.issuer_privkey or not self.issuer_gid:
\r
626 doc = parseString(self.get_xml())
\r
627 sigs = doc.getElementsByTagName("signatures")[0]
\r
629 # Create the signature template to be signed
\r
630 signature = Signature()
\r
631 signature.set_refid(self.get_refid())
\r
632 sdoc = parseString(signature.get_xml())
\r
633 sig_ele = doc.importNode(sdoc.getElementsByTagName("Signature")[0], True)
\r
634 sigs.appendChild(sig_ele)
\r
636 self.xml = doc.toxml()
\r
639 # Split the issuer GID into multiple certificates if it's a chain
\r
640 chain = GID(filename=self.issuer_gid)
\r
643 gid_files.append(chain.save_to_random_tmp_file(False))
\r
644 if chain.get_parent():
\r
645 chain = chain.get_parent()
\r
650 # Call out to xmlsec1 to sign it
\r
651 ref = 'Sig_%s' % self.get_refid()
\r
652 filename = self.save_to_random_tmp_file()
\r
653 signed = os.popen('%s --sign --node-id "%s" --privkey-pem %s,%s %s' \
\r
654 % (self.xmlsec_path, ref, self.issuer_privkey, ",".join(gid_files), filename)).read()
\r
655 os.remove(filename)
\r
657 for gid_file in gid_files:
\r
658 os.remove(gid_file)
\r
662 # This is no longer a legacy credential
\r
666 # Update signatures
\r
671 # Retrieve the attributes of the credential from the XML.
\r
672 # This is automatically called by the various get_* methods of
\r
673 # this class and should not need to be called explicitly.
\r
678 doc = parseString(self.xml)
\r
680 signed_cred = doc.getElementsByTagName("signed-credential")
\r
682 # Is this a signed-cred or just a cred?
\r
683 if len(signed_cred) > 0:
\r
684 creds = signed_cred[0].getElementsByTagName("credential")
\r
685 signatures = signed_cred[0].getElementsByTagName("signatures")
\r
686 if len(signatures) > 0:
\r
687 sigs = signatures[0].getElementsByTagName("Signature")
\r
689 creds = doc.getElementsByTagName("credential")
\r
691 if creds is None or len(creds) == 0:
\r
692 # malformed cred file
\r
693 raise CredentialNotVerifiable("Malformed XML: No credential tag found")
\r
695 # Just take the first cred if there are more than one
\r
698 self.set_refid(cred.getAttribute("xml:id"))
\r
699 self.set_expiration(utcparse(getTextNode(cred, "expires")))
\r
700 self.gidCaller = GID(string=getTextNode(cred, "owner_gid"))
\r
701 self.gidObject = GID(string=getTextNode(cred, "target_gid"))
\r
704 # Process privileges
\r
705 privs = cred.getElementsByTagName("privileges")[0]
\r
707 for priv in privs.getElementsByTagName("privilege"):
\r
708 kind = getTextNode(priv, "name")
\r
709 deleg = str2bool(getTextNode(priv, "can_delegate"))
\r
711 # Convert * into the default privileges for the credential's type
\r
712 # Each inherits the delegatability from the * above
\r
713 _ , type = urn_to_hrn(self.gidObject.get_urn())
\r
714 rl = determine_rights(type, self.gidObject.get_urn())
\r
715 for r in rl.rights:
\r
719 rlist.add(Right(kind.strip(), deleg))
\r
720 self.set_privileges(rlist)
\r
723 # Is there a parent?
\r
724 parent = cred.getElementsByTagName("parent")
\r
725 if len(parent) > 0:
\r
726 parent_doc = parent[0].getElementsByTagName("credential")[0]
\r
727 parent_xml = parent_doc.toxml()
\r
728 self.parent = Credential(string=parent_xml)
\r
731 # Assign the signatures to the credentials
\r
733 Sig = Signature(string=sig.toxml())
\r
735 for cur_cred in self.get_credential_list():
\r
736 if cur_cred.get_refid() == Sig.get_refid():
\r
737 cur_cred.set_signature(Sig)
\r
742 # trusted_certs: A list of trusted GID filenames (not GID objects!)
\r
743 # Chaining is not supported within the GIDs by xmlsec1.
\r
745 # trusted_certs_required: Should usually be true. Set False means an
\r
746 # empty list of trusted_certs would still let this method pass.
\r
747 # It just skips xmlsec1 verification et al. Only used by some utils
\r
750 # . All of the signatures are valid and that the issuers trace back
\r
751 # to trusted roots (performed by xmlsec1)
\r
752 # . The XML matches the credential schema
\r
753 # . That the issuer of the credential is the authority in the target's urn
\r
754 # . In the case of a delegated credential, this must be true of the root
\r
755 # . That all of the gids presented in the credential are valid
\r
756 # . Including verifying GID chains, and includ the issuer
\r
757 # . The credential is not expired
\r
759 # -- For Delegates (credentials with parents)
\r
760 # . The privileges must be a subset of the parent credentials
\r
761 # . The privileges must have "can_delegate" set for each delegated privilege
\r
762 # . The target gid must be the same between child and parents
\r
763 # . The expiry time on the child must be no later than the parent
\r
764 # . The signer of the child must be the owner of the parent
\r
766 # -- Verify does *NOT*
\r
767 # . ensure that an xmlrpc client's gid matches a credential gid, that
\r
768 # must be done elsewhere
\r
770 # @param trusted_certs: The certificates of trusted CA certificates
\r
771 def verify(self, trusted_certs=None, schema=None, trusted_certs_required=True):
\r
775 # validate against RelaxNG schema
\r
776 if HAVELXML and not self.legacy:
\r
777 if schema and os.path.exists(schema):
\r
778 tree = etree.parse(StringIO(self.xml))
\r
779 schema_doc = etree.parse(schema)
\r
780 xmlschema = etree.XMLSchema(schema_doc)
\r
781 if not xmlschema.validate(tree):
\r
782 error = xmlschema.error_log.last_error
\r
783 message = "%s: %s (line %s)" % (self.get_summary_tostring(), error.message, error.line)
\r
784 raise CredentialNotVerifiable(message)
\r
786 if trusted_certs_required and trusted_certs is None:
\r
789 # trusted_cert_objects = [GID(filename=f) for f in trusted_certs]
\r
790 trusted_cert_objects = []
\r
791 ok_trusted_certs = []
\r
792 # If caller explicitly passed in None that means skip cert chain validation.
\r
793 # Strange and not typical
\r
794 if trusted_certs is not None:
\r
795 for f in trusted_certs:
\r
797 # Failures here include unreadable files
\r
799 trusted_cert_objects.append(GID(filename=f))
\r
800 ok_trusted_certs.append(f)
\r
801 except Exception, exc:
\r
802 logger.error("Failed to load trusted cert from %s: %r", f, exc)
\r
803 trusted_certs = ok_trusted_certs
\r
805 # Use legacy verification if this is a legacy credential
\r
807 self.legacy.verify_chain(trusted_cert_objects)
\r
808 if self.legacy.client_gid:
\r
809 self.legacy.client_gid.verify_chain(trusted_cert_objects)
\r
810 if self.legacy.object_gid:
\r
811 self.legacy.object_gid.verify_chain(trusted_cert_objects)
\r
814 # make sure it is not expired
\r
815 if self.get_expiration() < datetime.datetime.utcnow():
\r
816 raise CredentialNotVerifiable("Credential %s expired at %s" % (self.get_summary_tostring(), self.expiration.isoformat()))
\r
818 # Verify the signatures
\r
819 filename = self.save_to_random_tmp_file()
\r
820 if trusted_certs is not None:
\r
821 cert_args = " ".join(['--trusted-pem %s' % x for x in trusted_certs])
\r
823 # If caller explicitly passed in None that means skip cert chain validation.
\r
824 # - Strange and not typical
\r
825 if trusted_certs is not None:
\r
826 # Verify the gids of this cred and of its parents
\r
827 for cur_cred in self.get_credential_list():
\r
828 cur_cred.get_gid_object().verify_chain(trusted_cert_objects)
\r
829 cur_cred.get_gid_caller().verify_chain(trusted_cert_objects)
\r
832 refs.append("Sig_%s" % self.get_refid())
\r
834 parentRefs = self.updateRefID()
\r
835 for ref in parentRefs:
\r
836 refs.append("Sig_%s" % ref)
\r
839 # If caller explicitly passed in None that means skip xmlsec1 validation.
\r
840 # Strange and not typical
\r
841 if trusted_certs is None:
\r
844 # print "Doing %s --verify --node-id '%s' %s %s 2>&1" % \
\r
845 # (self.xmlsec_path, ref, cert_args, filename)
\r
846 verified = os.popen('%s --verify --node-id "%s" %s %s 2>&1' \
\r
847 % (self.xmlsec_path, ref, cert_args, filename)).read()
\r
848 if not verified.strip().startswith("OK"):
\r
849 # xmlsec errors have a msg= which is the interesting bit.
\r
850 mstart = verified.find("msg=")
\r
852 if mstart > -1 and len(verified) > 4:
\r
853 mstart = mstart + 4
\r
854 mend = verified.find('\\', mstart)
\r
855 msg = verified[mstart:mend]
\r
856 raise CredentialNotVerifiable("xmlsec1 error verifying cred %s using Signature ID %s: %s %s" % (self.get_summary_tostring(), ref, msg, verified.strip()))
\r
857 os.remove(filename)
\r
859 # Verify the parents (delegation)
\r
861 self.verify_parent(self.parent)
\r
863 # Make sure the issuer is the target's authority, and is
\r
864 # itself a valid GID
\r
865 self.verify_issuer(trusted_cert_objects)
\r
869 # Creates a list of the credential and its parents, with the root
\r
870 # (original delegated credential) as the last item in the list
\r
871 def get_credential_list(self):
\r
875 list.append(cur_cred)
\r
876 if cur_cred.parent:
\r
877 cur_cred = cur_cred.parent
\r
883 # Make sure the credential's target gid (a) was signed by or (b)
\r
884 # is the same as the entity that signed the original credential,
\r
885 # or (c) is an authority over the target's namespace.
\r
886 # Also ensure that the credential issuer / signer itself has a valid
\r
887 # GID signature chain (signed by an authority with namespace rights).
\r
888 def verify_issuer(self, trusted_gids):
\r
889 root_cred = self.get_credential_list()[-1]
\r
890 root_target_gid = root_cred.get_gid_object()
\r
891 root_cred_signer = root_cred.get_signature().get_issuer_gid()
\r
894 # Allow non authority to sign target and cred about target.
\r
896 # Why do we need to allow non authorities to sign?
\r
897 # If in the target gid validation step we correctly
\r
898 # checked that the target is only signed by an authority,
\r
899 # then this is just a special case of case 3.
\r
900 # This short-circuit is the common case currently -
\r
901 # and cause GID validation doesn't check 'authority',
\r
902 # this allows users to generate valid slice credentials.
\r
903 if root_target_gid.is_signed_by_cert(root_cred_signer):
\r
904 # cred signer matches target signer, return success
\r
908 # Allow someone to sign credential about themeselves. Used?
\r
909 # If not, remove this.
\r
910 #root_target_gid_str = root_target_gid.save_to_string()
\r
911 #root_cred_signer_str = root_cred_signer.save_to_string()
\r
912 #if root_target_gid_str == root_cred_signer_str:
\r
913 # # cred signer is target, return success
\r
918 # root_cred_signer is not the target_gid
\r
919 # So this is a different gid that we have not verified.
\r
920 # xmlsec1 verified the cert chain on this already, but
\r
921 # it hasn't verified that the gid meets the HRN namespace
\r
923 # Below we'll ensure that it is an authority.
\r
924 # But we haven't verified that it is _signed by_ an authority
\r
925 # We also don't know if xmlsec1 requires that cert signers
\r
926 # are marked as CAs.
\r
927 root_cred_signer.verify_chain(trusted_gids)
\r
929 # See if the signer is an authority over the domain of the target.
\r
930 # There are multiple types of authority - accept them all here
\r
931 # Maybe should be (hrn, type) = urn_to_hrn(root_cred_signer.get_urn())
\r
932 root_cred_signer_type = root_cred_signer.get_type()
\r
933 if (root_cred_signer_type.find('authority') == 0):
\r
934 #logger.debug('Cred signer is an authority')
\r
935 # signer is an authority, see if target is in authority's domain
\r
936 signerhrn = root_cred_signer.get_hrn()
\r
937 if hrn_authfor_hrn(signerhrn, root_target_gid.get_hrn()):
\r
940 # We've required that the credential be signed by an authority
\r
941 # for that domain. Reasonable and probably correct.
\r
942 # A looser model would also allow the signer to be an authority
\r
943 # in my control framework - eg My CA or CH. Even if it is not
\r
944 # the CH that issued these, eg, user credentials.
\r
946 # Give up, credential does not pass issuer verification
\r
948 raise CredentialNotVerifiable("Could not verify credential owned by %s for object %s. Cred signer %s not the trusted authority for Cred target %s" % (self.gidCaller.get_urn(), self.gidObject.get_urn(), root_cred_signer.get_hrn(), root_target_gid.get_hrn()))
\r
952 # -- For Delegates (credentials with parents) verify that:
\r
953 # . The privileges must be a subset of the parent credentials
\r
954 # . The privileges must have "can_delegate" set for each delegated privilege
\r
955 # . The target gid must be the same between child and parents
\r
956 # . The expiry time on the child must be no later than the parent
\r
957 # . The signer of the child must be the owner of the parent
\r
958 def verify_parent(self, parent_cred):
\r
959 # make sure the rights given to the child are a subset of the
\r
960 # parents rights (and check delegate bits)
\r
961 if not parent_cred.get_privileges().is_superset(self.get_privileges()):
\r
962 raise ChildRightsNotSubsetOfParent(("Parent cred ref %s rights " % parent_cred.get_refid()) +
\r
963 self.parent.get_privileges().save_to_string() + (" not superset of delegated cred %s ref %s rights " % (self.get_summary_tostring(), self.get_refid())) +
\r
964 self.get_privileges().save_to_string())
\r
966 # make sure my target gid is the same as the parent's
\r
967 if not parent_cred.get_gid_object().save_to_string() == \
\r
968 self.get_gid_object().save_to_string():
\r
969 raise CredentialNotVerifiable("Delegated cred %s: Target gid not equal between parent and child. Parent %s" % (self.get_summary_tostring(), parent_cred.get_summary_tostring()))
\r
971 # make sure my expiry time is <= my parent's
\r
972 if not parent_cred.get_expiration() >= self.get_expiration():
\r
973 raise CredentialNotVerifiable("Delegated credential %s expires after parent %s" % (self.get_summary_tostring(), parent_cred.get_summary_tostring()))
\r
975 # make sure my signer is the parent's caller
\r
976 if not parent_cred.get_gid_caller().save_to_string(False) == \
\r
977 self.get_signature().get_issuer_gid().save_to_string(False):
\r
978 raise CredentialNotVerifiable("Delegated credential %s not signed by parent %s's caller" % (self.get_summary_tostring(), parent_cred.get_summary_tostring()))
\r
981 if parent_cred.parent:
\r
982 parent_cred.verify_parent(parent_cred.parent)
\r
985 def delegate(self, delegee_gidfile, caller_keyfile, caller_gidfile):
\r
987 Return a delegated copy of this credential, delegated to the
\r
988 specified gid's user.
\r
990 # get the gid of the object we are delegating
\r
991 object_gid = self.get_gid_object()
\r
992 object_hrn = object_gid.get_hrn()
\r
994 # the hrn of the user who will be delegated to
\r
995 delegee_gid = GID(filename=delegee_gidfile)
\r
996 delegee_hrn = delegee_gid.get_hrn()
\r
998 #user_key = Keypair(filename=keyfile)
\r
999 #user_hrn = self.get_gid_caller().get_hrn()
\r
1000 subject_string = "%s delegated to %s" % (object_hrn, delegee_hrn)
\r
1001 dcred = Credential(subject=subject_string)
\r
1002 dcred.set_gid_caller(delegee_gid)
\r
1003 dcred.set_gid_object(object_gid)
\r
1004 dcred.set_parent(self)
\r
1005 dcred.set_expiration(self.get_expiration())
\r
1006 dcred.set_privileges(self.get_privileges())
\r
1007 dcred.get_privileges().delegate_all_privileges(True)
\r
1008 #dcred.set_issuer_keys(keyfile, delegee_gidfile)
\r
1009 dcred.set_issuer_keys(caller_keyfile, caller_gidfile)
\r
1015 # only informative
\r
1016 def get_filename(self):
\r
1017 return getattr(self,'filename',None)
\r
1020 # Dump the contents of a credential to stdout in human-readable format
\r
1022 # @param dump_parents If true, also dump the parent certificates
\r
1023 def dump (self, *args, **kwargs):
\r
1024 print self.dump_string(*args, **kwargs)
\r
1027 def dump_string(self, dump_parents=False):
\r
1029 result += "CREDENTIAL %s\n" % self.get_subject()
\r
1030 filename=self.get_filename()
\r
1031 if filename: result += "Filename %s\n"%filename
\r
1032 result += " privs: %s\n" % self.get_privileges().save_to_string()
\r
1033 gidCaller = self.get_gid_caller()
\r
1035 result += " gidCaller:\n"
\r
1036 result += gidCaller.dump_string(8, dump_parents)
\r
1038 if self.get_signature():
\r
1039 print " gidIssuer:"
\r
1040 self.get_signature().get_issuer_gid().dump(8, dump_parents)
\r
1042 gidObject = self.get_gid_object()
\r
1044 result += " gidObject:\n"
\r
1045 result += gidObject.dump_string(8, dump_parents)
\r
1047 if self.parent and dump_parents:
\r
1048 result += "\nPARENT"
\r
1049 result += self.parent.dump_string(True)
\r