I have got one theoretical question related to extensions of X509 Certificate. More precisely I have question about what is happening when issuer signs subject's certificate with has several extensions, especially I am interested in three extensions, certificate policies, issuer alternative names and basic constraints.
Is Issuer Alternative Names extension being filled with issuer's Subject Alternative Names extension when signing certificate?
Is Certificate Policies extension being unchanged when sign is done by issuer?
EDIT: I have given only an interface of application, where I should implement logic behind it. So I am given extensions fields which I can fill only when I generate initial self-signed certificate. Basic constraints comes with "is critical" checkbox, "is CA" checkbox and "path length" integer field. So I am confused when I fill those data when I generate self-signed, and when Issuer after that signs my previous certificate, what is happening with this extension.