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xmldigestxml-dsig

URI in XML-DSIG and digest calculation

I am analyzing an XML-DSIG file in order to know how to write my piece of software code that generates XML-DSIGnatures. I am having this trouble and desperately need help... I am trying to understand this bit from signatures0.xml (quoted after this bit):

<Reference Type="http://uri.etsi.org/01903#SignedProperties" URI="#SignedPropertiesElem_0" xmlns="http://www.w3.org/2000/09/xmldsig#">
        <Transforms xmlns="http://www.w3.org/2000/09/xmldsig#">
            <Transform Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
        </Transforms>
        <DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/>
        <DigestValue>kOlNXyBs6oSP9hbh+4niZMNQ9OsOCzYhkSYYG4YdHQU=</DigestValue>
    </Reference>

signatures0.xml:

<?xml version="1.0" encoding="UTF-8"?>
<document-signatures xmlns="urn:oasis:names:tc:opendocument:xmlns:digitalsignature:1.0">
<Signature Id="SignatureElem_0" xmlns="http://www.w3.org/2000/09/xmldsig#" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<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="metadata/signableMetadata0.xml" xmlns="http://www.w3.org/2000/09/xmldsig#">
            <Transforms xmlns="http://www.w3.org/2000/09/xmldsig#">
                <Transform Algorithm="http://www.w3.org/TR/1999/REC-xpath-19991116">
                    <XPath>ancestor-or-self::*[@ID='signature_0']</XPath>
                </Transform>
                <Transform Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
            </Transforms>
            <DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/>
            <DigestValue>XIrOvoOM33rWvV5Fdckax/bNLOpR9RNIonkVQ22fczM=</DigestValue>
        </Reference>
        <Reference URI="1.docx" xmlns="http://www.w3.org/2000/09/xmldsig#">
            <DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/>
            <DigestValue>LtTwOA0L3mL4mswjGL3JwkumufovE/A75M4MGSUm6PQ=</DigestValue>
        </Reference>
        <Reference Type="http://uri.etsi.org/01903#SignedProperties" URI="#SignedPropertiesElem_0" xmlns="http://www.w3.org/2000/09/xmldsig#">
            <Transforms xmlns="http://www.w3.org/2000/09/xmldsig#">
                <Transform Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
            </Transforms>
            <DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/>
            <DigestValue>kOlNXyBs6oSP9hbh+4niZMNQ9OsOCzYhkSYYG4YdHQU=</DigestValue>
        </Reference>
</SignedInfo>
<SignatureValue>
EPuWjb6IeuYg32FT1tInmO7FPL1ISuluFvrPqzHdHyJ0ymgMFitaWPJQk0MV6ckgmvFwif6zpg5C
XLVJl4U+e/+AmS1AkwMf2TmnuIONuB8oLeYcDUCr+0xxlwgKSZoopzapD7ylZxIwCPTMr6BT3lx9
8EFHHVskC4wVihR0JsJWBl2YzGnBevCWpknGofa8t8vOHpTA2y9VSAu5ETXnKYF5Ms04kTy5NQ7G
kHcslw+HSAuaJolvfUd4EeqAXVFz9V7sE+akQ20fciw9QQH8gttF8bIous8dsv3/6Zmtclvbk17Q
79pI+2o7JKhZIh9ct0PHTMpU5KV6GEXxIrCb4g==
</SignatureValue>
<KeyInfo>
<X509Data>
<X509Certificate>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</X509Certificate>
</X509Data>
</KeyInfo>
<Object>
        <QualifyingProperties Target="#SignatureElem_0" xmlns="http://uri.etsi.org/01903/v1.3.2#">
            <SignedProperties Id="SignedPropertiesElem_0">
                <SignedSignatureProperties>
                    <SigningTime>2014-08-21T06:09:55Z</SigningTime>
                    <SigningCertificate>
                        <Cert>
                            <CertDigest>
                                <DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256" xmlns="http://www.w3.org/2000/09/xmldsig#"/>
                                <DigestValue xmlns="http://www.w3.org/2000/09/xmldsig#">JQ0kZvd0mtXQPA/RTuYV9iuc346tznvN9MoAd/0jNyM=</DigestValue>
                            </CertDigest>
                            <IssuerSerial>
                                <X509IssuerName xmlns="http://www.w3.org/2000/09/xmldsig#">CN=Nacionalinis sertifikavimo centras (IssuingCA-B),OU=Nacionalinis sertifikavimo centras (NSC),O=Gyventoju registro tarnyba prie LR VRM - i.k. 188756767,C=LT</X509IssuerName>
                                <X509SerialNumber xmlns="http://www.w3.org/2000/09/xmldsig#">1315010063538360283821765366094690</X509SerialNumber>
                            </IssuerSerial>
                        </Cert>
                    </SigningCertificate>
                    <SignaturePolicyIdentifier>
                        <SignaturePolicyImplied/>
                    </SignaturePolicyIdentifier>
                </SignedSignatureProperties>
            </SignedProperties>
        </QualifyingProperties>
    </Object>
</Signature></document-signatures>

From what I understand, the first quoted bit refers to a SignedPropertiesElem_0 element in the same file. I am trying to determine exactly what it refers to - what piece of code exactly should be selected and used later on for canonicalization and then calculating a digest value. Is it this:

<SignedProperties Id="SignedPropertiesElem_0">
                <SignedSignatureProperties>
                    <SigningTime>2014-08-21T06:09:55Z</SigningTime>
                    <SigningCertificate>
                        <Cert>
                            <CertDigest>
                                <DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256" xmlns="http://www.w3.org/2000/09/xmldsig#"/>
                                <DigestValue xmlns="http://www.w3.org/2000/09/xmldsig#">JQ0kZvd0mtXQPA/RTuYV9iuc346tznvN9MoAd/0jNyM=</DigestValue>
                            </CertDigest>
                            <IssuerSerial>
                                <X509IssuerName xmlns="http://www.w3.org/2000/09/xmldsig#">CN=Nacionalinis sertifikavimo centras (IssuingCA-B),OU=Nacionalinis sertifikavimo centras (NSC),O=Gyventoju registro tarnyba prie LR VRM - i.k. 188756767,C=LT</X509IssuerName>
                                <X509SerialNumber xmlns="http://www.w3.org/2000/09/xmldsig#">1315010063538360283821765366094690</X509SerialNumber>
                            </IssuerSerial>
                        </Cert>
                    </SigningCertificate>
                    <SignaturePolicyIdentifier>
                        <SignaturePolicyImplied/>
                    </SignaturePolicyIdentifier>
                </SignedSignatureProperties>
            </SignedProperties>

Or this:

<SignedSignatureProperties>
                    <SigningTime>2014-08-21T06:09:55Z</SigningTime>
                    <SigningCertificate>
                        <Cert>
                            <CertDigest>
                                <DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256" xmlns="http://www.w3.org/2000/09/xmldsig#"/>
                                <DigestValue xmlns="http://www.w3.org/2000/09/xmldsig#">JQ0kZvd0mtXQPA/RTuYV9iuc346tznvN9MoAd/0jNyM=</DigestValue>
                            </CertDigest>
                            <IssuerSerial>
                                <X509IssuerName xmlns="http://www.w3.org/2000/09/xmldsig#">CN=Nacionalinis sertifikavimo centras (IssuingCA-B),OU=Nacionalinis sertifikavimo centras (NSC),O=Gyventoju registro tarnyba prie LR VRM - i.k. 188756767,C=LT</X509IssuerName>
                                <X509SerialNumber xmlns="http://www.w3.org/2000/09/xmldsig#">1315010063538360283821765366094690</X509SerialNumber>
                            </IssuerSerial>
                        </Cert>
                    </SigningCertificate>
                    <SignaturePolicyIdentifier>
                        <SignaturePolicyImplied/>
                    </SignaturePolicyIdentifier>
                </SignedSignatureProperties>

Or this:

<SigningTime>2014-08-21T06:09:55Z</SigningTime>
                    <SigningCertificate>
                        <Cert>
                            <CertDigest>
                                <DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256" xmlns="http://www.w3.org/2000/09/xmldsig#"/>
                                <DigestValue xmlns="http://www.w3.org/2000/09/xmldsig#">JQ0kZvd0mtXQPA/RTuYV9iuc346tznvN9MoAd/0jNyM=</DigestValue>
                            </CertDigest>
                            <IssuerSerial>
                                <X509IssuerName xmlns="http://www.w3.org/2000/09/xmldsig#">CN=Nacionalinis sertifikavimo centras (IssuingCA-B),OU=Nacionalinis sertifikavimo centras (NSC),O=Gyventoju registro tarnyba prie LR VRM - i.k. 188756767,C=LT</X509IssuerName>
                                <X509SerialNumber xmlns="http://www.w3.org/2000/09/xmldsig#">1315010063538360283821765366094690</X509SerialNumber>
                            </IssuerSerial>
                        </Cert>
                    </SigningCertificate>
                    <SignaturePolicyIdentifier>
                        <SignaturePolicyImplied/>
                    </SignaturePolicyIdentifier>

Or some other part of it?

I tried the first one, then letting it through a StylusStudio canonicalization OR http://www.soapclient.com/xmlcanon.html (both seem to return identical results), which results in this:

<SignedProperties Id="SignedPropertiesElem_0">
                <SignedSignatureProperties>
                    <SigningTime>2014-08-21T06:09:55Z</SigningTime>
                    <SigningCertificate>
                        <Cert>
                            <CertDigest>
                                <DigestMethod xmlns="http://www.w3.org/2000/09/xmldsig#" Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"></DigestMethod>
                                <DigestValue xmlns="http://www.w3.org/2000/09/xmldsig#">JQ0kZvd0mtXQPA/RTuYV9iuc346tznvN9MoAd/0jNyM=</DigestValue>
                            </CertDigest>
                            <IssuerSerial>
                                <X509IssuerName xmlns="http://www.w3.org/2000/09/xmldsig#">CN=Nacionalinis sertifikavimo centras (IssuingCA-B),OU=Nacionalinis sertifikavimo centras (NSC),O=Gyventoju registro tarnyba prie LR VRM - i.k. 188756767,C=LT</X509IssuerName>
                                <X509SerialNumber xmlns="http://www.w3.org/2000/09/xmldsig#">1315010063538360283821765366094690</X509SerialNumber>
                            </IssuerSerial>
                        </Cert>
                    </SigningCertificate>
                    <SignaturePolicyIdentifier>
                        <SignaturePolicyImplied></SignaturePolicyImplied>
                    </SignaturePolicyIdentifier>
                </SignedSignatureProperties>
            </SignedProperties>

and then calculating the digest value using these tools: http://www.webutils.pl/index.php?idx=sha1 hash.online-convert.com/sha256-generator www.freeformatter.com/message-digest.html#ad-output

They all returned the same result, but that result is different from the one in the xml file: kOlNXyBs6oSP9hbh+4niZMNQ9OsOCzYhkSYYG4YdHQU=

What am I doing wrong? What part of the xml document should I copy and paste into the canonicalizer and then into digest calculator? I've spent several days trying different things and looking for answers and haven't got anything... I am sure I missed something, therefore I am asking for your help.

Solution

  • I found out that the result should be:

    <SignedProperties Id="SignedPropertiesElem_0">
                <SignedSignatureProperties>
                    <SigningTime>2014-08-21T06:09:55Z</SigningTime>
                    <SigningCertificate>
                        <Cert>
                            <CertDigest>
                                <DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256" xmlns="http://www.w3.org/2000/09/xmldsig#"/>
                                <DigestValue xmlns="http://www.w3.org/2000/09/xmldsig#">JQ0kZvd0mtXQPA/RTuYV9iuc346tznvN9MoAd/0jNyM=</DigestValue>
                            </CertDigest>
                            <IssuerSerial>
                                <X509IssuerName xmlns="http://www.w3.org/2000/09/xmldsig#">CN=Nacionalinis sertifikavimo centras (IssuingCA-B),OU=Nacionalinis sertifikavimo centras (NSC),O=Gyventoju registro tarnyba prie LR VRM - i.k. 188756767,C=LT</X509IssuerName>
                                <X509SerialNumber xmlns="http://www.w3.org/2000/09/xmldsig#">1315010063538360283821765366094690</X509SerialNumber>
                            </IssuerSerial>
                        </Cert>
                    </SigningCertificate>
                    <SignaturePolicyIdentifier>
                        <SignaturePolicyImplied/>
                    </SignaturePolicyIdentifier>
                </SignedSignatureProperties>
            </SignedProperties>

    The reason I couldn't get the right digest value after canonicalization was because the software didn't include all applicable namespace declarations and it was also supposed to have xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" declared.

    And the problem with web hash calculators is that when you copy and paste text in Windows, LF line breaks get replaced by CR+LF.