Method declaration not found

[Gnorxan]

When I 'make' crudesaml, I get a warning
"saml.c:383:11: warning: implicit declaration of function ‘lasso_provider_verify_saml_signature’ [-Wimplicit-function-declaration]
error = lasso_provider_verify_saml_signature(idp, node, doc);"

The method declaration is in lasso/id-ff/providerprivate.h which is not public.