I have internet facing 6 custom applications (in house developed using java) deployedon premise. Currently, application authentication is happening against application DB (username/ password stored in Oracle DB). We would like to integrate these 6 applications with Azure AD so that they can have seamless SSO between them. These application does not support open standards (SAML, OAuth/OIDC etc) also there is noon premise Active Directory in place.
I am looking for options to integrate these applications with Azure AD. I did some research and found below 2 options but not sure if they are the correctoptions. Here are my queries.
1) If I make these 6 applications to support SAML (these are custom applications I can code and make them as SP) will I be able to integrate with Azure AD (IdP)? Since these are Internet facing do I need Azure AD proxy connectoron premise for SAML integration?
2) Will I be able to integrate with header based authentication (using Azure AD proxy connector and ping access)?
3) Any other options integrate other than above two?