Secure applications require a client to be authenticated as a valid application user and have authorization to access servlets and JSPs.
Applications with a secure web container may enforce the following security processes for clients:
Authenticate the caller
Authorize the caller for access to each servlet/JSP based on the applicable access control configuration
Authentication is the process of confirming an identity. Authorization means granting access to a restricted resource to an identity, and access control mechanisms enforce these restrictions. Authentication and authorization can be enforced by a number of security models and services.
Sun Java System Web Server 6.1 provides authentication and authorization support through the following mechanisms, which are discussed in this section:
ACL-based authentication and authorization
J2SE/Servlet-based authentication and authorization
Whether performed by the ACL subsystem or the J2SE/Servlet authentication subsystem, authentication and authorization are still the two fundamental operations that define secure web content.
ACL-based access control is described at length in the Sun Java System Web Server 6.1 Administrator’s Guide. This section provides a brief overview of the key concepts.
Sun Java System Web Server 6.1 supports authentication and authorization through the use of locally stored access control lists (ACLs), which describe what access rights a user has for a resource. For example, an entry in an ACL can grant a user named John read permission to a particular folder named misc:
acl "path=/export/user/990628.1/docs/misc/"; authenticate (user,group) { database = "default"; method = "basic"; }; deny (all) (user = "John"); allow (read); |
The core ACLs in Sun Java System Web Server 6.1 support three types of authentication: basic, certificate, and digest.
Basic authentication relies on lists of user names and passwords passed as cleartext. Certificates bind a name to a public key. Digest authentication uses encryption techniques to encrypt the user’s credentials.
The main features of the ACL-based access control model are described below:
ACL-based authentication uses the following configuration files:
server-install/httpacl/*.acl files
server-install/userdb/dbswitch.conf
server-install/config/server.xml
Authentication is performed by auth-db modules that are configured in the dbswitch.conf file.
Authorization is performed by access control rules set in the server-install/httpacl/*.acl files, if ACLs are configured.
In addition, the Sun Java System Web Server 6.1 SSL engine supports external crypto hardware to offload SSL processing and to provide optional tamper-resistant key storage.
For more information about access control and the use of external crypto hardware, see the Sun Java System Web Server 6.1 SP12 Administrator’s Guide.
Sun Java System Web Server 6.1, apart from providing ACL-based authentication, also leverages the security model defined in the J2SE 1.3 specification to provide several features that help you develop and deploy secure Java web applications.
A typical J2SE-based web application consists of the following parts, access to any or all of which can be restricted:
Servlets
JavaServer Pages (JSP) components
HTML documents
Miscellaneous resources, such as image files and compressed archives
The J2SE/Servlet-based access control infrastructure relies on the use of security realms. When a user tries to access the main page of an application through a web browser, the web container prompts for the user's credential information, and then passes it for verification to the realm that is currently active in the security service.
A realm, also called a security policy domain or security domain in the J2SE specification, is a scope over which a common security policy is defined and enforced by the security administrator of the security service.
The main features of the J2SE/Servlet-based access control model are described below:
J2SE/Servlet-based authentication uses the following configuration files:
The web application deployment descriptor files web.xml and sun-web.xml
server-install/config/server.xml
Authentication is performed by Java security realms that are configured through AUTHREALM entries in the server.xml file.
Authorization is performed by access control rules in the deployment descriptor file, web.xml, in case any such rules have been set.