progress: enable xmldsig and do other cleanups

xmlsec.go

@@ -0,0 +1,151 @@
+package xmlsec
+
+import (
+	"errors"
+	"unsafe"
+)
+
+// Note: on mac you need:
+//   brew install libxmlsec1 libxml2
+//   brew link libxml2 --force
+
+// #cgo pkg-config: xmlsec1
+// #include <xmlsec/xmlsec.h>
+// #include <xmlsec/xmltree.h>
+// #include <xmlsec/xmlenc.h>
+// #include <xmlsec/errors.h>
+// #include <xmlsec/templates.h>
+// #include <xmlsec/crypto.h>
+import "C"
+
+// #cgo pkg-config: libxml-2.0
+// #include <libxml/parser.h>
+// #include <libxml/parserInternals.h>
+// #include <libxml/xmlmemory.h>
+//
+// // xmlFree is a macro, so we need to wrap it in order to be able to call
+// // it from go code.
+// static inline void MY_xmlFree(void *p) {
+//   xmlFree(p);
+// }
+import "C"
+
+// void onError_cgo(char *file, int line, char *funcName, char *errorObject, char *errorSubject, int reason, char *msg);
+import "C"
+
+func init() {
+	C.xmlInitParser()
+
+	if rv := C.xmlSecInit(); rv < 0 {
+		panic("xmlsec failed to initialize")
+	}
+	if rv := C.xmlSecCryptoAppInit(nil); rv < 0 {
+		panic("xmlsec crypto initialization failed.")
+	}
+	if rv := C.xmlSecCryptoInit(); rv < 0 {
+		panic("xmlsec crypto initialization failed.")
+	}
+
+	C.xmlSecErrorsSetCallback((C.xmlSecErrorsCallback)(unsafe.Pointer(C.onError_cgo)))
+}
+
+func newDoc(buf []byte) (*C.xmlDoc, error) {
+	ctx := C.xmlCreateMemoryParserCtxt((*C.char)(unsafe.Pointer(&buf[0])),
+		C.int(len(buf)))
+	if ctx == nil {
+		return nil, errors.New("error creating parser")
+	}
+	defer C.xmlFreeParserCtxt(ctx)
+
+	//C.xmlCtxtUseOptions(ctx, C.int(p.Options))
+	C.xmlParseDocument(ctx)
+
+	if ctx.wellFormed == C.int(0) {
+		return nil, errors.New("malformed XML")
+	}
+
+	doc := ctx.myDoc
+	if doc == nil {
+		return nil, errors.New("parse failed")
+	}
+
+	return doc, nil
+}
+
+func newDoc2(buf []byte, opts DsigOptions) (*C.xmlDoc, error) {
+	ctx := C.xmlCreateMemoryParserCtxt((*C.char)(unsafe.Pointer(&buf[0])),
+		C.int(len(buf)))
+	if ctx == nil {
+		return nil, errors.New("error creating parser")
+	}
+	defer C.xmlFreeParserCtxt(ctx)
+
+	//C.xmlCtxtUseDsigOptions(ctx, C.int(p.DsigOptions))
+	C.xmlParseDocument(ctx)
+
+	if ctx.wellFormed == C.int(0) {
+		return nil, errors.New("malformed XML")
+	}
+
+	doc := ctx.myDoc
+	if doc == nil {
+		return nil, errors.New("parse failed")
+	}
+
+	for _, idattr := range opts.XMLID {
+		addIDAttr(C.xmlDocGetRootElement(doc),
+			idattr.AttributeName, idattr.ElementName, idattr.ElementNamespace)
+	}
+	return doc, nil
+}
+
+func addIDAttr(node *C.xmlNode, attrName, nodeName, nsHref string) {
+	// process children first because it does not matter much but does simplify code
+	cur := C.xmlSecGetNextElementNode(node.children)
+	for {
+		if cur == nil {
+			break
+		}
+		addIDAttr(cur, attrName, nodeName, nsHref)
+		cur = C.xmlSecGetNextElementNode(cur.next)
+	}
+
+	if C.GoString((*C.char)(unsafe.Pointer(node.name))) != nodeName {
+		return
+	}
+	if nsHref != "" && node.ns != nil && C.GoString((*C.char)(unsafe.Pointer(node.ns.href))) != nsHref {
+		return
+	}
+
+	// the attribute with name equal to attrName should exist
+	for attr := node.properties; attr != nil; attr = attr.next {
+		if C.GoString((*C.char)(unsafe.Pointer(attr.name))) == attrName {
+			id := C.xmlNodeListGetString(node.doc, attr.children, 1)
+			if id == nil {
+				continue
+			}
+			C.xmlAddID(nil, node.doc, id, attr)
+		}
+	}
+
+	return
+}
+func closeDoc(doc *C.xmlDoc) {
+	C.xmlFreeDoc(doc)
+}
+
+func dumpDoc(doc *C.xmlDoc) []byte {
+	var buffer *C.xmlChar
+	var bufferSize C.int
+	C.xmlDocDumpMemory(doc, &buffer, &bufferSize)
+	rv := C.GoStringN((*C.char)(unsafe.Pointer(buffer)), bufferSize)
+	C.MY_xmlFree(unsafe.Pointer(buffer))
+
+	// TODO(ross): this is totally nasty un-idiomatic, but I'm
+	// tired of googling how to copy a []byte from a char*
+	return []byte(rv)
+}
+
+func constXmlChar(s string) *C.xmlChar {
+	return (*C.xmlChar)(unsafe.Pointer(C.CString(s)))
+}