IMO, the error is clear: can't open file. Aleksey > > func=xmlSecTransformInputURIOpen:file=..\src\io.c:line=423:obj=input-uri:subj=opencallback:error=7:io > function failed:uri=file:///sample.xml;errno=2 > > Does it mean that sinature is invalid or it can't find a file? > Is URI "_file:///myfile.doc_" OK? (detached signature in separate file)