// Sign returns a version of doc signed with key according to
// the XMLDSIG standard. doc is a template document meaning
// that it contains an `http://www.w3.org/2000/09/xmldsig#Signature`
// element whose properties define how and what to sign.
func Sign(key []byte, doc []byte, opts SignatureOptions) ([]byte, error) {
startProcessingXML()
defer stopProcessingXML()
ctx := C.xmlSecDSigCtxCreate(nil)
if ctx == nil {
return nil, errors.New("failed to create signature context")
}
defer C.xmlSecDSigCtxDestroy(ctx)
ctx.signKey = C.xmlSecCryptoAppKeyLoadMemory(
(*C.xmlSecByte)(unsafe.Pointer(&key[0])),
C.xmlSecSize(len(key)),
C.xmlSecKeyDataFormatPem,
nil, nil, nil)
if ctx.signKey == nil {
return nil, errors.New("failed to load pem key")
}
parsedDoc, err := newDoc(doc, opts.XMLID)
if err != nil {
return nil, err
}
defer closeDoc(parsedDoc)
node := C.xmlSecFindNode(C.xmlDocGetRootElement(parsedDoc),
(*C.xmlChar)(unsafe.Pointer(&C.xmlSecNodeSignature)),
(*C.xmlChar)(unsafe.Pointer(&C.xmlSecDSigNs)))
if node == nil {
return nil, errors.New("cannot find start node")
}
if rv := C.xmlSecDSigCtxSign(ctx, node); rv < 0 {
return nil, errors.New("failed to sign")
}
return dumpDoc(parsedDoc), nil
}
func xmlSecDSigCtxSignRaw(ctxptr *C.xmlSecDSigCtx, nodeptr *C.xmlNode) error {
if C.xmlSecDSigCtxSign(ctxptr, nodeptr) < C.int(0) {
return errors.New("failed to sign node")
}
return nil
}