(Ruby) Verify HMAC XML Digital Signature

Demonstrates how to validate an XML digital signature signed with an HMAC key.

Chilkat Ruby Downloads install from rubygems.org gem install chilkat or download... Ruby Library for Windows, MacOS, Linux, Alpine Linux

require 'chilkat'

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

# The XML containing the Signature to be verified contains the following:

# <?xml version="1.0" encoding="UTF-8" standalone="no"?>
# <collection Id="root">
# 	<album>
# 		<title>Questions, unanswered</title>
# 		<artist>Steve and the flubberblubs</artist>
# 		<year>1989</year>
# 		<t:tracks xmlns:t="http://test.xades4j/tracks">
# 			<t:song length="4:05" tracknumber="1">
# 				<t:title>What do you know?</t:title>
# 				<t:artist>Steve and the flubberblubs</t:artist>
# 				<t:lastplayed>2006-10-17-08:31</t:lastplayed>
# 			</t:song>
# 			<t:song length="3:45" tracknumber="2">
# 				<t:title>Who do you know?</t:title>
# 				<t:artist>Steve and the flubberblubs</t:artist>
# 				<t:lastplayed>2006-10-17-08:35</t:lastplayed>
# 			</t:song>
# 			<t:song length="5:14" tracknumber="3">
# 				<t:title>When do you know?</t:title>
# 				<t:artist>Steve and the flubberblubs</t:artist>
# 				<t:lastplayed>2006-10-17-08:39</t:lastplayed>
# 			</t:song>
# 			<t:song length="4:19" tracknumber="4">
# 				<t:title>Do you know?</t:title>
# 				<t:artist>Steve and the flubberblubs</t:artist>
# 				<t:lastplayed>2006-10-17-08:44</t:lastplayed>
# 			</t:song>
# 		</t:tracks>
# 	</album>
# <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#hmac-sha256"/><ds:Reference URI="#root"><ds:Transforms><ds:Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature"/></ds:Transforms><ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/><ds:DigestValue>rD/g8soqKz8EiPUBhEWfcQacS0ta4ULHX3dKMEH6ZoQ=</ds:DigestValue></ds:Reference></ds:SignedInfo><ds:SignatureValue>R8dXP95VRYJBfL6d0Peogybdk27+R+JIfX8jnVu0NOI=</ds:SignatureValue></ds:Signature></collection>

# The above XML is available at https://www.chilkatsoft.com/exampleData/hmacSigned.xml
# First fetch the XML..

url = "https://www.chilkatsoft.com/exampleData/hmacSigned.xml"
http = Chilkat::CkHttp.new()
sbXml = Chilkat::CkStringBuilder.new()
success = http.QuickGetSb(url,sbXml)
if (success != true)
    print http.lastErrorText() + "\n";
    exit
end

verifier = Chilkat::CkXmlDSig.new()

# Load the XML containing the signature to be verified.
success = verifier.LoadSignatureSb(sbXml)
if (success != true)
    print verifier.lastErrorText() + "\n";
    exit
end

# Provide the HMAC key
# The HMAC key for this signature is the us-ascii bytes of the string "secret",
# It can be set in any of the following ways (and also more ways not shown here..)
verifier.SetHmacKey("secret","ascii")
# or
verifier.SetHmacKey("c2VjcmV0","base64")
# or
verifier.SetHmacKey("736563726574","hex")

# Verify the signature
bVerified = verifier.VerifySignature(true)
print "Signature verified = " + bVerified.to_s() + "\n";