Re: [Pgi-wg] [gridshib-user] comments regarding a VOMS-SAML token--ANY plan to make VOMS SAML assertion be compatible with WS-Security SAML Token profile?

30 Mar 2009

      hi,
According to the specification of SAML Token profile 1.1 (
http://www.oasis-open.org/committees/download.php/16768/wss-v1.1-spec-os-SAM...),
I listed the difference as follows, some of the points are trivial .

For a SAML Token which is compliant to SAML V1.1:

<saml:Assertion xmlns:saml="..."
  AssertionID="_a75adf55-01d7-40cc-929f-dbd8372ebdfc"
  IssueInstant="2005-05-27T16:53:33.173Z"
  Issuer=”www.opensaml.org”
  MajorVersion="1"
  MinorVersion="1">
  <saml:Conditions
    NotBefore="2005-05-27T16:53:33.173Z"
    NotOnOrAfter="2005-05-27T16:58:33.17302Z"/>
  <saml:AttributeStatement>
    <saml:Subject>
      <saml:NameIdentifier
                  NameQualifier="www.example.com"
                  Format=“urn:oasis:names:tc:SAML:1.1:nameid-
    format:X509SubjectName”>
                  uid=joe,ou=people,ou=saml-demo,o=baltimore.com
                </saml:NameIdentifier>
                <saml:SubjectConfirmation>
                  <saml:ConfirmationMethod>
                    urn:oasis:names:tc:SAML:1.0:cm:holder-of-key
                  </saml:ConfirmationMethod>
                  <ds:KeyInfo>
                    <ds:KeyValue>...</ds:KeyValue>
                  </ds:KeyInfo>
                </saml:SubjectConfirmation>
              </saml:Subject>
              <saml:Attribute
                AttributeName="MemberLevel"
                AttributeNamespace="http://www.oasis-
    open.org/Catalyst2002/attributes">
                <saml:AttributeValue>gold</saml:AttributeValue>
              </saml:Attribute>
              <saml:Attribute
                AttributeName="E-mail"
                AttributeNamespace="
http://www.oasis-open.org/Catalyst2002/attributes">
                <saml:AttributeValue>joe@yahoo.com</saml:AttributeValue>
              </saml:Attribute>
            </saml:AttributeStatement>
            <ds:Signature>...</ds:Signature>
          </saml:Assertion>

For a SAML Token which is compliant to SAML V2.0:

<saml2:Assertion xmlns:saml2="..." xmlns:xsi="..."
   ID=”_a75adf55-01d7-40cc-929f-dbd8372ebdfc”>
<saml2:Subject>
 <saml2:NameID>
     ...
 </saml2:NameID>
 <saml2:SubjectConfirmation
       Method=”urn:oasis:names:tc:SAML:2.0:cm:holder-of-key”>
       <saml2:SubjectConfirmationData
          xsi:type="saml2:KeyInfoConfirmationDataType">
          <ds:KeyInfo>
             <ds:KeyValue>...</ds:KeyValue>
          </ds:KeyInfo>
       </saml2:SubjectConfirmationData>
    </saml2:SubjectConfirmation>
</saml2:Subject>
<saml2:Statement>
 ...
</saml2:Statement>
   <ds:Signature>...</ds:Signature>
</saml2:Assertion>

Suppose voms saml assertion uses SAML V2.0

Some comments:
1. The signature for <saml:Reponse> could also be necessary, even though the
integrity is guaranteed by TLS.

2. xml attribute  xsi:type="saml2:KeyInfoConfirmationDataType" could be
necessary for <saml2:SubjectConfirmationData/>

3. <saml:SubjectConfirmation> element contains a <ds:X509Certificate>
element, but it probably be better to just contain a <ds:KeyValue>, since
the certificates chain of the "subject" is already supposed to be verified
by the third-party authority (in this case, it is voms saml service), and
then this public key is used to sign the soap message afterwards. For SOAP
message verification on the rely-party side, the rely-party do not need to
verify the certificates chain of "subject".
<ds:KeyValue> is also convinient for proxy certificate, in my opinion.

4. Use <saml:Statement> instead of <saml:AttributeStatement>.

Cheers,
Weizhong

On Mon, Mar 30, 2009 at 5:00 PM, Tom Scavo <trscavo@gmail.com> wrote:
...
Hi Weizhong,
Can you outline why you think the VOMS SAML assertion is not
compatible with the WSS SAML Token Profile?
Thanks,
Tom
PS. The comments quoted below mostly refer to a VOMS SAML assertion
bound to an X.509 proxy certificate (but the requirements are not the
same as a VOMS SAML assertion bound to SOAP header).
On Mon, Mar 30, 2009 at 10:25 AM, weizhong qiang
<weizhongqiang@gmail.com> wrote:
...
hi voms folks, all,
The current voms SAML assertion is not compatible with WS-Security SAML
Token profile. I would ask is there any plan to change it to make it be
compatible? I ask this because I think if so, the SAML assertion can be
used
for SOAP message layer authentication, other than just including SAML
attribute assertion.
Thanks
Weizhong Qiang
On Tue, Feb 10, 2009 at 5:21 AM, Tom Scavo <trscavo@gmail.com> wrote:
...
Thanks to Benjamin for posting this VOMS-SAML response to gt-user.  A
critique (of the SAML, not Benjamin :) follows.
- Note that the output is a <samlp:Response> element, not a
<saml:Assertion> element.  This is wrong.  The requester must consume
the response.  Not sure why this isn't happening.
- The value of the <saml:Issuer> element in the response is a DN but
the Format XML attribute is missing.  This is a bug.  The default
Format is "unspecified" but clearly this is not.
- Second-level status codes are desirable so they can be echoed on the
command line (if any).
- Same comment about the <saml:Issuer> element in the assertion.
- The use of SAML metadata requires that the Format on the
<saml:Issuer> element be "entity" but clearly it is not.  Thus the use
of SAML metadata by the relying party is precluded.
- Don't know if Shibboleth/OpenSAML can verify the signature (which is
tricky business).  This is a future experiment that needs to be done.
- The <saml:SubjectConfirmation> element contains a
<ds:X509Certificate> element, which precludes the binding of this
holder-of-key assertion to a proxy certificate.  This is a bug.  Use a
<ds:X509SubjectName> element instead (which causes the NameID itself
to be redundant).
- If the assertion is bound to a proxy certificate, the NotBefore and
NotOnOrAfter attributes are redundant and superfluous.  In fact, they
may be wrong since they must agree with the NotBefore and NotOnOrAfter
fields of the proxy.
- Since the client authenticated directly to the server, a
<saml:AuthnStatement> is desirable (not required, but potentially
useful at the relying party).
- The NameFormat XML attribute on the <saml:Attribute> element should
be "uri" not "unspecified".
- The "xsi:" prefix on the <saml:AttributeValue> element is undefined.
 This is a bug.
- The <saml:AttributeValue> elements do not conform to the XACML
Attribute Profile (actually, I don't think the attributes conform to
*any* SAML V2.0 attribute profile).
Hope this helps,
Tom
---------- Forwarded message ----------
From: Benjamin Henne <henne@rvs.uni-hannover.de>
Date: Wed, Feb 4, 2009 at 1:59 AM
Subject: Re: [gt-user] SAML based VOMS Server
To: Tom Scavo <trscavo@gmail.com>
Cc: GT User <gt-user@globus.org>
<Response xmlns="urn:oasis:names:tc:SAML:2.0:protocol"
xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol"
ID="_d01d46b7-d16a-4ae8-b9bb-beb8844838b6"
InResponseTo="_qwertyuiopasdfghjklzxcvbn"
IssueInstant="2008-10-16T19:03:57.922Z" Version="2.0">
 <saml:Issuer
xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion">CN=
voms3.gridlab.uni-hannover.de
,OU=UniHannover,O=GermanGrid,C=DE</saml:Issuer>
...
<Status>
  <StatusCode Value="urn:oasis:names:tc:SAML:2.0:status:Success"/>
 </Status>
 <saml:Assertion xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion"
ID="_81b685e5-4650-4ba9-b1c6-0ed957cc33ac"
IssueInstant="2008-10-16T19:03:57.920Z" Version="2.0">
<saml:Issuer>CN=voms3.gridlab.uni-hannover.de
,OU=UniHannover,O=GermanGrid,C=DE</saml:Issuer>
  <ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
<ds:SignedInfo>
<ds:CanonicalizationMethod
Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/>
<ds:SignatureMethod
Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/>
<ds:Reference URI="#_81b685e5-4650-4ba9-b1c6-0ed957cc33ac">
<ds:Transforms>
<ds:Transform
Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature"/>
<ds:Transform
Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#
"><ec:InclusiveNamespaces
xmlns:ec="http://www.w3.org/2001/10/xml-exc-c14n#" PrefixList="ds saml
xs"/></ds:Transform>
</ds:Transforms>
<ds:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>
<ds:DigestValue>j55K/cn8GQNuTQ52Kr3r0NGRJ0w=</ds:DigestValue>
</ds:Reference>
</ds:SignedInfo>
<ds:SignatureValue>
...
</ds:SignatureValue>
<ds:KeyInfo><ds:X509Data><ds:X509Certificate>...</ds:X509Certificate></ds:X509Data></ds:KeyInfo></ds:Signature>
...
<saml:Subject>
    <saml:NameID
Format="urn:oasis:names:tc:SAML:1.1:nameid-format:X509SubjectName">CN=Benjamin
...
Henne,OU=UniHannover,O=GermanGrid,C=DE</saml:NameID>
    <saml:SubjectConfirmation
Method="urn:oasis:names:tc:SAML:2.0:cm:holder-of-key">
      <saml:SubjectConfirmationData>
        <ds:KeyInfo xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
          <ds:X509Data>
            <ds:X509Certificate>...</ds:X509Certificate>
          </ds:X509Data>
        </ds:KeyInfo>
      </saml:SubjectConfirmationData>
    </saml:SubjectConfirmation>
  </saml:Subject>
  <saml:Conditions NotBefore="2008-10-16T19:03:57.920Z"
NotOnOrAfter="2008-10-17T06:03:57.920Z"/>
  <saml:AttributeStatement>
    <saml:Attribute Name="http://voms.forge.cnaf.infn.it/roles"
NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:unspecified">
      <saml:AttributeValue
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xsi:type="xs:string">VO-Admin@/RVS</saml:AttributeValue>
      <saml:AttributeValue
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xsi:type="xs:string">resass@/RVS/education</saml:AttributeValue>
      <saml:AttributeValue
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xsi:type="xs:string">staff@/RVS/research/SAML</saml:AttributeValue>
    </saml:Attribute>
    <saml:Attribute Name="nationality"
NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:unspecified">
      <saml:AttributeValue
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xsi:type="xs:string">German</saml:AttributeValue>
    </saml:Attribute>
    <saml:Attribute Name="http://voms.forge.cnaf.infn.it/group"
NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:unspecified">
      <saml:AttributeValue
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xsi:type="xs:string">/RVS/education</saml:AttributeValue>
      <saml:AttributeValue
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xsi:type="xs:string">/RVS</saml:AttributeValue>
      <saml:AttributeValue
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xsi:type="xs:string">/RVS/research</saml:AttributeValue>
    </saml:Attribute>
  </saml:AttributeStatement>
 </saml:Assertion>
</Response>

weizhong qiang

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