C14N10 REC Canonicalizer does not follow

[adamdecaf]

Taking Example 3.3 from the REC-xml-c14n-20010315 specification does not properly canonicalize the document.

--- FAIL: TestC14N10RecCanonicalizer (0.00s)
    canonicalize_test.go:31: 
        	Error Trace:	canonicalize_test.go:31
        	            				canonicalize_test.go:118
        	Error:      	Not equal: 
        	            	expected: "<doc>\n   <e1></e1>\n   <e2></e2>\n   <e3 id=\"elem3\" name=\"elem3\"></e3>\n   <e4 id=\"elem4\" name=\"elem4\"></e4>\n   <e5 xmlns=\"http://example.org\" xmlns:a=\"http://www.w3.org\" xmlns:b=\"http://www.ietf.org\" attr=\"I'm\" attr2=\"all\" b:attr=\"sorted\" a:attr=\"out\"></e5>\n   <e6 xmlns:a=\"http://www.w3.org\">\n      <e7 xmlns=\"http://www.ietf.org\">\n         <e8 xmlns=\"\">\n            <e9 xmlns:a=\"http://www.ietf.org\" attr=\"default\"></e9>\n         </e8>\n      </e7>\n   </e6>\n</doc>"
        	            	actual  : "<doc>\n   <e1></e1>\n   <e2></e2>\n   <e3 id=\"elem3\" name=\"elem3\"></e3>\n   <e4 id=\"elem4\" name=\"elem4\"></e4>\n   <e5 xmlns=\"http://example.org\" xmlns:a=\"http://www.w3.org\" xmlns:b=\"http://www.ietf.org\" attr=\"I'm\" attr2=\"all\" b:attr=\"sorted\" a:attr=\"out\"></e5>\n   <e6 xmlns=\"\" xmlns:a=\"http://www.w3.org\">\n      <e7 xmlns=\"http://www.ietf.org\">\n         <e8 xmlns=\"\">\n            <e9 xmlns=\"\"></e9>\n         </e8>\n      </e7>\n   </e6>\n</doc>"
        	            	
        	            	Diff:
        	            	--- Expected
        	            	+++ Actual
        	            	@@ -6,6 +6,6 @@
        	            	    <e5 xmlns="http://example.org" xmlns:a="http://www.w3.org" xmlns:b="http://www.ietf.org" attr="I'm" attr2="all" b:attr="sorted" a:attr="out"></e5>
        	            	-   <e6 xmlns:a="http://www.w3.org">
        	            	+   <e6 xmlns="" xmlns:a="http://www.w3.org">
        	            	       <e7 xmlns="http://www.ietf.org">
        	            	          <e8 xmlns="">
        	            	-            <e9 xmlns:a="http://www.ietf.org" attr="default"></e9>
        	            	+            <e9 xmlns=""></e9>
        	            	          </e8>
        	Test:       	TestC14N10RecCanonicalizer
FAIL
FAIL	github.com/russellhaering/goxmldsig	1.175s

It appears we are injecting empty xmlns attributes into the response.