HTTP-Redirect Binding SAML Request

问题

Suppose SP-init SSO is carried out, HTTP-Redirect Binding is used instead of HTTP-POST Binding and signed AuthnRequest is required. It means to include the SAMLRequest in the URL.

Q1. Do I need to include the signature in the URL or just embed in the SAMLRequest ?

The redirect url is

http://idp.example.com/SSOService.php?SAMLRequest={val1}&Signature={val2}&SigAlg={val3}

with my SAMLRequest (without signature)

<samlp:AuthnRequest ID="" Version="2.0" IssueInstant="2015-05-22T02:47:38Z" Destination="" ProtocolBinding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST" AssertionConsumerServiceURL="" xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol">
    <saml:Issuer xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion"></saml:Issuer>
    <samlp:NameIDPolicy Format="urn:oasis:names:tc:SAML:1.1:nameid-format:emailAddress" AllowCreate="true" />
    <samlp:RequestedAuthnContext Comparison="exact" />
    <saml:AuthnContextClassRef xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion">urn:oasis:names:tc:SAML:2.0:ac:classes:PasswordProtectedTransport</saml:AuthnContextClassRef>
</samlp:AuthnRequest>

or

http://idp.example.com/SSOService.php?SAMLRequest={val1}

with my SAMLRequest (embed with signature)

<samlp:AuthnRequest ID="" Version="2.0" IssueInstant="2015-05-22T02:47:38Z" Destination="" ProtocolBinding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST" AssertionConsumerServiceURL="" xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol">
    <saml:Issuer xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion"></saml:Issuer>
    <samlp:NameIDPolicy Format="urn:oasis:names:tc:SAML:1.1:nameid-format:emailAddress" AllowCreate="true" />
    <samlp:RequestedAuthnContext Comparison="exact" />
    <saml:AuthnContextClassRef xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion">urn:oasis:names:tc:SAML:2.0:ac:classes:PasswordProtectedTransport</saml:AuthnContextClassRef>
    <Signature xmlns="http://www.w3.org/2000/09/xmldsig#">
        <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="">
                <Transforms>
                    <Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature" />
                </Transforms>
                <DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1" />
                <DigestValue>v5h...</DigestValue>
            </Reference>
        </SignedInfo>
        <SignatureValue>M4...</SignatureValue>
    </Signature>
</samlp:AuthnRequest>

Q2. Is it correct to do base64 and url encoded to the value of url parameters ?

Q3. X509 Certificate is included in my SP metadata, is it base64-encoded ?

I have a cert.pem file for the certificate, do I need to make it base64-encoded or just include the certificate directly.

-----BEGIN CERTIFICATE-----
MII...
-----END CERTIFICATE-----

SPMetadata.xml

<KeyDescriptor use="signing">
            <ds:KeyInfo xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
                <ds:X509Data>
                    <ds:X509Certificate>MIIFnzCCA4egAwI...</ds:X509Certificate>
                </ds:X509Data>
            </ds:KeyInfo>
        </KeyDescriptor>

回答1:

A1: when using the Redirect binding you put the signature in the URL query parameters

A2: all URL query parameters should be url-encoded, just the SAML Request should be compressed and base64-encoded in addition to that.

A3: use the PEM format since that is base64 encoded already but leave out the start and end delimiters (----BEGIN-- and ----END CERT...)

来源：https://stackoverflow.com/questions/30388926/http-redirect-binding-saml-request