HMAC SHA1 ColdFusion

Question

Please help! I have been pulling out my hair over this one. :)

I have a site that I need to HMAC SHA1 for authentication. It currently works with another language but now I need to move it to ColdFusion. For the life of me I cannot get the strings to match. Any assistance would be much appreciated.

Data: https%3A%2F%2Fwww%2Etestwebsite%2Ecom%3Fid%3D5447
Key: 265D5C01D1B4C8FA28DC55C113B4D21005BB2B348859F674977B24E0F37C81B05FAE85FB75EA9CF53ABB9A174C59D98C7A61E2985026D2AA70AE4452A6E3F2F9

Correct answer: WJd%2BKxmFxGWdbw4xQJZXd3%2FHkFQ%3d
My answer: knIVr6wIt6%2Fl7mBJPTTbwQoTIb8%3d

Both are Base64 encoded and then URL encoded.

Answer 1

Doing an HMAC-SHA1 thing myself. Best I can say is that I found this old function. Has worked great for what I am doing thus far. Forgot where I found it though so I can't credit the author.

For your Base 64 stuff... run this function on your encryption, then just do a cfset newString = toBase64(oldString) on what is returned.

<cffunction name="hmacEncrypt" returntype="binary" access="public" output="false">
   <cfargument name="signKey" type="string" required="true" />
   <cfargument name="signMessage" type="string" required="true" />

   <cfset var jMsg = JavaCast("string",arguments.signMessage).getBytes("iso-8859-1") />
   <cfset var jKey = JavaCast("string",arguments.signKey).getBytes("iso-8859-1") />

   <cfset var key = createObject("java","javax.crypto.spec.SecretKeySpec") />
   <cfset var mac = createObject("java","javax.crypto.Mac") />

   <cfset key = key.init(jKey,"HmacSHA1") />

   <cfset mac = mac.getInstance(key.getAlgorithm()) />
   <cfset mac.init(key) />
   <cfset mac.update(jMsg) />

   <cfreturn mac.doFinal() />
</cffunction>

Answer 2

Steve - Thanks for your response. I actually was using the hmacEncrypt function already. I did figure out my issue though. I was passing in a HEX key instead of a string. It accepted the key because technically it was a string. To get it back to a string I used another function along with the one above. The one below changes the HEX into a string. I didn't write the function below nor do I remember where it came from to get the author credit, but it worked great.

<cffunction name="Hex2Bin" returntype="any" hint="Converts a Hex string to binary">
    <cfargument name="inputString" type="string" required="true" hint="The hexadecimal string to be written.">
    <cfset var outStream = CreateObject("java", "java.io.ByteArrayOutputStream").init()>
    <cfset var inputLength = Len(arguments.inputString)>
    <cfset var outputString = "">
    <cfset var i = 0>
    <cfset var ch = "">
    <cfif inputLength mod 2 neq 0>
    <cfset arguments.inputString = "0" & inputString>
    </cfif>
    <cfloop from="1" to="#inputLength#" index="i" step="2">
        <cfset ch = Mid(inputString, i, 2)>
        <cfset outStream.write(javacast("int", InputBaseN(ch, 16)))>
    </cfloop>
    <cfset outStream.flush()>
    <cfset outStream.close()> 
    <cfreturn outStream.toByteArray()>
</cffunction> 

Answer 3

Wow - I wrote Hex2Bin years ago for someone on the CFC mailing list! Just as an FYI, as of CF7, you can now do this:

BinaryDecode(inputString, "hex")

It's much simpler (and more performant) since they added the built-in function.