xml - 如何手动验证 SAMLResponse 签名？

Question

给定以下 SAML 响应，我如何手动验证签名是否有效？我假设我应该依赖元数据中提供的 IDP 证书，而不是响应本身中的证书(尽管它们应该是相同的)。

有什么方法可以用 openssl 或 xmlsec1 命令做到这一点吗？

<samlp:Response xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol" ID="s2a79da8e2cd2eda272fd5d2d474858f1919430a96" Version="2.0" IssueInstant="2016-08-25T00:24:45Z" Destination="http://10.88.111.163:8080/zport/dmd">
  <saml:Issuer xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion">https://idp.ssocircle.com</saml:Issuer>
  <samlp:Status xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol">
<samlp:StatusCode xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol" Value="urn:oasis:names:tc:SAML:2.0:status:Success">
</samlp:StatusCode>
</samlp:Status>
  <saml:Assertion xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion" ID="s22b55a88e8022a4d198715d5b3f21c3fbd699dac4" IssueInstant="2016-08-25T00:24:45Z" Version="2.0">
<saml:Issuer>https://idp.ssocircle.com</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="#s22b55a88e8022a4d198715d5b3f21c3fbd699dac4">
<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#"/>
</ds:Transforms>
<ds:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>
<ds:DigestValue>abEMP7cxDW8LwnvcUzr2dHmQesk=</ds:DigestValue>
</ds:Reference>
</ds:SignedInfo>
<ds:SignatureValue>
#SIGNATURE#
</ds:SignatureValue>
<ds:KeyInfo>
<ds:X509Data>
<ds:X509Certificate>
#CERTIFICATE#
</ds:X509Certificate>
</ds:X509Data>
</ds:KeyInfo>
</ds:Signature><saml:Subject>
<saml:NameID Format="urn:oasis:names:tc:SAML:1.1:nameid-format:unspecified" NameQualifier="https://idp.ssocircle.com" SPNameQualifier="instance">ben</saml:NameID><saml:SubjectConfirmation Method="urn:oasis:names:tc:SAML:2.0:cm:bearer">
<saml:SubjectConfirmationData NotOnOrAfter="2016-08-25T00:34:45Z" Recipient="http://10.88.111.163:8080/zport/dmd"/></saml:SubjectConfirmation>
</saml:Subject><saml:Conditions NotBefore="2016-08-25T00:14:45Z" NotOnOrAfter="2016-08-25T00:34:45Z">
<saml:AudienceRestriction>
<saml:Audience>instance</saml:Audience>
</saml:AudienceRestriction>
</saml:Conditions>
<saml:AuthnStatement AuthnInstant="2016-08-25T00:16:14Z" SessionIndex="s2e2b6d389c12dd386a118286d1228e159faee1901"><saml:AuthnContext><saml:AuthnContextClassRef>urn:oasis:names:tc:SAML:2.0:ac:classes:PasswordProtectedTransport</saml:AuthnContextClassRef></saml:AuthnContext></saml:AuthnStatement><saml:AttributeStatement><saml:Attribute Name="EmailAddress"><saml:AttributeValue xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="xs:string">me@email.com</saml:AttributeValue></saml:Attribute><saml:Attribute Name="FirstName"><saml:AttributeValue xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="xs:string">Ben</saml:AttributeValue></saml:Attribute></saml:AttributeStatement></saml:Assertion>
</samlp:Response>

Answer 1

假设验证证书在一个名为 cert.pem 的文件中并且(未修改的，逐字的)SAML 响应在 response.xml 中，xmlsec1 可用于验证响应上的签名，如下所示:

xmlsec1 verify --id-attr:ID "urn:oasis:names:tc:SAML:2.0:protocol:Response" --pubkey-cert-pem cert.pem response.xml