Aleksey:
Yes -- you're right. I even recall reading a discussion about this in the
discussion of enveloped signatures in the specification. I wondered at the time
why they used the convoluted XPath count function rather than a more direct
approach -- now I get it.
In any event - I suspect that Apache is actually still signing/verifying the
entire document just like XMLSEC is *trying* to do. So .. I should be able to
verify this document also using XMLSEC. Do you have any idea from the sample our
it's output as to why it fails to validate the Reference? This is *always* the
hard part of digital signature work -- when it doesn't work -- figuring out
*why* it failed. What bit is wrong where ...
Thanks!
Ferrell
-----Original Message-----Hi, Moultrie!
From: Aleksey Sanin [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, July 24, 2002 9:22 PM
To: Moultrie, Ferrell (ISSAtlanta)
Cc: '[EMAIL PROTECTED]'; Dodd, Tim (ISS Atlanta)
Subject: Re: [xmlsec] XMLSEC Reference URI question
I think that there is a "bug" in the document you provided and Apache
toolkit incorrectly implemented XPath transform. According to the XMLDSig
spec (http://www.w3.org/TR/xmldsig-core/#sec-XPath) the XPath transform
is evaluated as follows:
> In other words, the input node-set should be equivalent to the one that would be created by
> the following process:
> 1. Initialize an XPath evaluation context by setting the initial node equal to the input XML
> document's root node, and set the context position and size to 1.
> 2. Evaluate the XPath expression(//. | //@* | //namespace::*)
> The evaluation of this expression includes all of the document's nodes (including comments) in the
> node-set representing the octet stream.
> The transform output is also an XPath node-set. The XPath expression appearing in theXPath
> parameter is evaluated once for each node in the input node-set. The result is converted to a
> boolean. If the boolean is true, then the node is included in the output node-set. If the boolean is
> false, then the node is omitted from the output node-set.
In our case, the XPath expression in the XPath parameter is "/ISSKeys/Contacts/Contact"
Evaluating this XPath expression returns a non-empty node set and according to the
XPath spec (http://www.w3.org/TR/1999/REC-xpath-19991116#booleans) it is converted
to boolean by a call to the boolean() function. From the same spec, (http://www.w3.org/TR/1999/REC-xpath-19991116#function-boolean)
the boolean() function *always* returns true for non-empty node set:
> a node-set is true if and only if it is non-empty
For the document you sent me, this means that the XPath expression from the XPath
parameter will be "true" for *all* nodes and *all* nodes should be included in the output.
And this is exactly what XMLSec library returns!
I totally agree with you that such behavior is absolutely not intuitive and can cause errors.
XMLDSig working group is now developing a new XPath transform spec (XPath filter 2) and
this particular issue is fixed there. However, this new spec is not stable right now and changes
almost every day so I could not recommend to use it in production yet.
Aleksey
Moultrie, Ferrell (ISSAtlanta) wrote:
xmlsec verify --print-all --trusted new_export.pem test_allkey_04.xml I've included the PEM-formatted public key, the XML test document and the output captured from running the 07/12/02 build of xmlsec plus the one fix you sent me earlier. Let me know if you need anything else. Thanks! Ferrell -----Original Message----- From: Aleksey Sanin [mailto:[EMAIL PROTECTED]] Sent: Wednesday, July 24, 2002 5:48 PM To: Moultrie, Ferrell (ISSAtlanta) Cc: '[EMAIL PROTECTED]'; Dodd, Tim (ISS Atlanta) Subject: Re: [xmlsec] XMLSEC Reference URI question I am not sure I clear understand what kind of problem do you have. Will you mind to send me the file you have problems with? Thanks, Aleksey Moultrie, Ferrell (ISSAtlanta) wrote:Aleksey: Ok, I've tried to use an XPath Transform to limit the data being verified. Unfortunately, it doesn't appear to work. Here's what I see happening in the code: xmlSecTransformXPathReadNode( ) [xpath.c:203] takes the input xmlSecTransformPtr and upcasts it to a xmlSecXmlTransformPtr. It then stores the parsed XPath string and the "here" node reference in the xmlSecXmlTransform object it points to (at least there's checking of the pointer assignment sanity here). The caller, xmlSecTransformRead, returns to its caller xmlSecTransformNodeRead with the pointer to the object containing the XPath transform information. The transform is further passed back to xmlSecTransformsNodeRead which calls xmlSecTransformStateUpdate which discovers that the transform type is xmlSecTransformTypeXml and call xmlSecTransformCreateXml. This routine, because the file is already parsed and both curFirstBinTransform and curC14NTransform in the state object are NULL, does nothing and returns! This results in the XPath Transform information being parsed and saved but otherwise ignored. The <Signature> block contains the following transform which is parsed and ignored in the above case: <sig:Transform Algorithm="http://www.w3.org/TR/1999/REC-xpath-19991116"> <sig:XPath>/ISSKeys/Contacts/Contact</sig:XPath> </sig:Transform> The result is that adding an XPath transform like above, is ignored. This works properly with the Apache Java tools so I believe that it's a legal way to construct a reference. Eventually, I'd intended to change the XPath reference to a here()-relative reference to solve my compound document problem but this seemed like a quick/easy test -- unfortunately it's not working. Is this a bug, or, have I missed something else? Since Apache properly verifies this signature and the code in xmlSecTransformCreateXml seems to be missing any knowledge of this transform, I'm guessing that it's a bug -- but I'll appreciate your advice on how to proceed! Thanks! Ferrell ===================================== Ferrell Moultrie ([EMAIL PROTECTED]) Software Engineer Internet Security Systems, Inc. 6303 Barfield Road Atlanta, Georgia 30328 Phone: 404-236-2600 Direct: 404-236-2849 Fax: 404-236-2632 http://www.iss.net Internet Security Systems -- The Power to Protect ===================================== _______________________________________________ xmlsec mailing list [EMAIL PROTECTED] http://www.aleksey.com/mailman/listinfo/xmlsec
xmlSecSignedInfoRead: failed to validate "Reference" = XMLDSig Result (validate) == result: FAIL == sign method: http://www.w3.org/2000/09/xmldsig#rsa-sha1 == KEY === method: RSAKeyValue === key name: NULL === key type: Public === key origin: x509 === X509 Certificate ==== Subject Name: /C=US/O=Web Developer/OU=IT/CN=ISS Keygen Test ==== Issuer Name: /C=US/O=Web Developer/OU=IT/CN=ISS Keygen Test ==== Issuer Serial: 3CEF18C2 == SIGNED INFO REFERENCES === REFERENCE ==== ref type: SignedInfo Reference ==== result: FAIL ==== digest method: http://www.w3.org/2000/09/xmldsig#sha1 ==== uri: ==== type: NULL ==== id: NULL ==== start buffer: <ISSKeys Source="ISS Atlanta"> <Contacts> <Contact> <Keys Address1="2626 Somewhere Lane" Address2="suite 200A" City="Atlanta" Country="US" Email="[EMAIL PROTECTED]" Fax="778-555-1212" Phone="777.555.1212" PostCode="30064" Weburl="http://web.fubar.net"></Keys> <CustomerRelations Address1="1313 k nowwhere Lane" Address2="suite 300A" City="Atlanta" Country="US" Email="[EMAIL PROTECTED]" Fax="778-555-7799" Phone="77 7.555.7788" PostCode="30064" Weburl="http://web.customer_relations_iss.net"></CustomerRelations> <Support Address1="1234 Anvil Rd." Address2="suite 440B" City="Atlanta" Country="US" Email="[EMAIL PROTECTED]" Fax="778-555-7755" Phone="777.555.7744" PostCode="3 0064" Weburl="http://web.suport_iss.net"></Support> <Version>1.0</Version> <OCN>163444</OCN> <Source>ISS Atlanta</Source> <Serial>AC C64BB4-A53D-AC83-3E6F-E0AB737DEC9D</Serial> <Timestamp>2000-06-14 10:34:09</Timestamp> <sig:Signature xmlns:sig="http://www.w3.org/2000/09/xmldsig#"> <sig:SignedInfo> <sig:CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"></sig:CanonicalizationMethod> <sig:SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"></sig:SignatureMethod> <sig:Reference URI=""> <sig:Transforms> <sig:Transform Algorithm="http://www.w3.org/TR/1999/REC-xpath-19991116"> <sig:XPath>/ISSKeys/Contacts/Contact</sig:XPath> </sig:Transform> <sig:Transform Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315#WithComments"></sig:Transform> </sig:Transforms> <sig:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"></sig:DigestMethod> <sig:DigestValue>3tPX5xUmcKYHkG3Mv8TBAAYjBIU=</sig:DigestValue> </sig:Reference> </sig:SignedInfo> <sig:SignatureValue>GpbCX9juwQ6k4Hs5j19MSXdtAdxeY9cK06Hb17ugq7f6sIy71gafWWNJ1Na/TKGCrABlgrXWH2VR asYcPMEmi1RZKDPUzmPAjznKRozjZTS3nn2BrAl1EKLugiqYmer+IG8SOXXTDSiwbmphtsXK+emU FpUVVxfjLrmk8h6hd4k=</sig:SignatureValue> <sig:KeyInfo> <sig:X509Data> <sig:X509Certificate> MIICCjCCAXMCBDzvGMIwDQYJKoZIhvcNAQEEBQAwTDELMAkGA1UEBhMCVVMxFjAUBgNVBAoTDVdl YiBEZXZlbG9wZXIxCzAJBgNVBAsTAklUMRgwFgYDVQQDEw9JU1MgS2V5Z2VuIFRlc3QwHhcNMDIw NTI1MDQ1MzIyWhcNMjcwMTE0MDQ1MzIyWjBMMQswCQYDVQQGEwJVUzEWMBQGA1UEChMNV2ViIERl dmVsb3BlcjELMAkGA1UECxMCSVQxGDAWBgNVBAMTD0lTUyBLZXlnZW4gVGVzdDCBnzANBgkqhkiG 9w0BAQEFAAOBjQAwgYkCgYEAy6ACsVtGJ69fkeKxJUlZqUP4FJFDIrkrUEi04c8UAAmC6jxu9+mM uLD+766Ztrjp/2anYX0QS7ReD+Q78ky3a0nmPDIpAzv8P7tUCBc6Yq11w5c1yHSNDdLPxLlX6+JT nUXnmXMsfAyC2cnoevc38gfEEkEJnS4iCzUC7WHsNgMCAwEAATANBgkqhkiG9w0BAQQFAAOBgQBy 08EvqGY4QL5GYhuT5Lx26t7V0Tk9bKxzh9YKxtyTLux0sqDFcAQWu1UpjPSOLwgNhE+uaS+CuyIK wsSzMx84gOIk7/fOS5F7oRk2ouC0QPPhY0iT2wXi9Zhvd6CifjNwvCdDe0tinSeQNfvpo0FSlg8c GL2eqXYylPEeMvZ5aw== </sig:X509Certificate> </sig:X509Data> <sig:KeyValue> <sig:RSAKeyValue> <sig:Modulus> y6ACsVtGJ69fkeKxJUlZqUP4FJFDIrkrUEi04c8UAAmC6jxu9+mMuLD+766Ztrjp/2anYX0QS7Re D+Q78ky3a0nmPDIpAzv8P7tUCBc6Yq11w5c1yHSNDdLPxLlX6+JTnUXnmXMsfAyC2cnoevc38gfE EkEJnS4iCzUC7WHsNgM= </sig:Modulus> <sig:Exponent>AQAB</sig:Exponent> </sig:RSAKeyValue> </sig:KeyValue> </sig:KeyInfo> </sig:Signature> </Contact> </Contacts> <EndUsers> <EndUser Address1="666 Rockets way" Address2="Apt. B" City="Scienceville" CompanyName="Spacely Sprockets" Country="US" Email="[EMAIL PROTECTED]" PostCode="" State="Disturbed" SubjectName=FAIL "George Jetson" Title="Whipping Boy"> <Version>1.0</Version> <OCN>163444</OCN> <Source>ISS Atlanta</Source> <Serial>CE8135D7-8D27-4BC4-BCA6-2DBDE703B6A E</Serial> <Timestamp>2000-06-14 10:34:09</Timestamp> </EndUser> </EndUsers> <LicensedModules> <LicensedModule ContactInfo="ACC64BB4- A53D-AC83-3E6F-E0AB737DEC9D" EndUserInfo="CE8135D7-8D27-4BC4-BCA6-2DBDE703B6AE" Identity="RO" LicenseExpiration="2003-06-14" LicenseType="evaluation" Limit="2147483647" LimitOutOfMaintenance="0" MaintenanceExpiration="2003-06-14"> <Version>1.0</Version> <OCN>163444</OCN> <Source>ISS Atlanta</Source> <Serial>F61BD0F3-D5D9-2F90-A24D-BF989200D712</Serial> <Timestamp>2000-06-14 10:34:09</Timestamp> </LicensedModule> </LicensedModules> </ISSKeys> ==== end buffer: = Status: == Signatures ok: 0 == Signatures fail: 1 == SignedInfo Ref ok: 0 == SignedInfo Ref fail: 1 == Manifest Ref ok: 0 == Manifest Ref fail: 0 Error: operation failed
