Lua

SAML Signature Validation

See more XML Digital Signatures Examples

A SAML Signature is an XML Digital Signature (XMLDSig) just like any other XML digital signature. It can be verified by using Chilkat' XmlDSig class, as shown in this example. Lua

local chilkat = require("chilkat")

-- This example requires the Chilkat API to have been previously unlocked.
-- See Global Unlock Sample for sample code.

local dsig = chilkat.XmlDSig.new()
local success = dsig:load_signature("XML xml signature goes here...")

-- A sample SAML signature is shown below..

local numSignatures = dsig.num_signatures
local i = 0
while i < numSignatures do
    dsig.selector = i

    local bVerifyRefDigests = false
    local bSignatureVerified = dsig:verify_signature(bVerifyRefDigests)
    if bSignatureVerified then
        print("Signature " .. (i + 1) .. " verified")
    else
        print("Signature " .. (i + 1) .. " invalid")
    end

    -- Check each of the reference digests separately..
    local numRefDigests = dsig.num_references
    local j = 0
    while j < numRefDigests do
        local bDigestVerified = dsig:verify_reference_digest(j)
        print("reference digest " .. (j + 1) .. " verified = " .. tostring(bDigestVerified))
        if not bDigestVerified then
            print("    reference digest fail reason: " .. dsig.ref_fail_reason)
        end

        j = j + 1
    end

    i = i + 1
end

-- --------------------------------------
-- Here is a sample SAML XML Signature
--
--
-- <?xml version="1.0" encoding="UTF-8"?>
-- <saml2p:Response xmlns:saml2p="urn:oasis:names:tc:SAML:2.0:protocol" ID="abc123" Version="2.0" IssueInstant="2022-04-01T12:34:56Z" Destination="https://sp.example.com/sso">
--   <saml2:Issuer xmlns:saml2="urn:oasis:names:tc:SAML:2.0:assertion">https://idp.example.com</saml2:Issuer>
--   <saml2p:Status>
--     <saml2p:StatusCode Value="urn:oasis:names:tc:SAML:2.0:status:Success"/>
--   </saml2p:Status>
--   <saml2:Assertion xmlns:saml2="urn:oasis:names:tc:SAML:2.0:assertion" ID="def456" IssueInstant="2022-04-01T12:34:56Z" Version="2.0">
--     <saml2:Issuer>https://idp.example.com</saml2:Issuer>
--     <saml2:Subject>
--       <saml2:NameID Format="urn:oasis:names:tc:SAML:1.1:nameid-format:emailAddress">user@example.com</saml2:NameID>
--     </saml2:Subject>
--     <saml2:Conditions NotBefore="2022-04-01T12:34:56Z" NotOnOrAfter="2022-04-01T13:34:56Z"/>
--     <saml2:AuthnStatement AuthnInstant="2022-04-01T12:34:56Z">
--       <saml2:AuthnContext>
--         <saml2:AuthnContextClassRef>urn:oasis:names:tc:SAML:2.0:ac:classes:Password</saml2:AuthnContextClassRef>
--       </saml2:AuthnContext>
--     </saml2:AuthnStatement>
--     <!-- Additional assertion content -->
--   </saml2:Assertion>
--   <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/2001/04/xmldsig-more#rsa-sha256"/>
--       <ds:Reference URI="#abc123">
--         <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/2001/04/xmlenc#sha256"/>
--         <ds:DigestValue>q7Zj1w+...+pCsjw=</ds:DigestValue>
--       </ds:Reference>
--       <!-- Additional references if present -->
--     </ds:SignedInfo>
--     <ds:SignatureValue>
--       NjIzOWE5ZjA2M2M1...NzUwNzUwNzUwNzUwNzU=
--     </ds:SignatureValue>
--     <ds:KeyInfo>
--       <ds:X509Data>
--         <ds:X509Certificate>
--           MIIDgzCCAmugAwIBAg...AgADAA==
--         </ds:X509Certificate>
--       </ds:X509Data>
--     </ds:KeyInfo>
--   </ds:Signature>
-- </saml2p:Response>