An application, library, or kernel module that obtains cryptographic services is called a consumer. An application that provides cryptographic services to consumers through the framework is referred to as a provider and also as a plug–in. The software that implements a cryptographic operation is called a mechanism. A mechanism is not just the algorithm but includes the way in which the algorithm is to be applied. For example, the DES algorithm when applied to authentication is considered a separate mechanism. DES when applied to block-by-block encryption would be a different mechanism.
A token is the abstraction of a device that can perform cryptography. In addition, tokens can store information for use in cryptographic operations. A single token can support one or more mechanisms. Tokens can represent hardware, as in an accelerator board. Tokens that represent pure software are referred to as soft tokens. A token can be plugged into a slot, which continues the physical metaphor. A slot is the connecting point for applications that use cryptographic services.
In addition to specific slots for providers, the Oracle Solaris implementation provides a special slot called the metaslot. The metaslot is a component of the Oracle Solaris cryptographic framework library (libpkcs11.so). The metaslot serves as a single virtual slot with the combined capabilities of all tokens and slots that have been installed in the framework. Effectively, the metaslot enables an application to transparently connect with any available cryptographic service through a single slot. When an application requests a cryptographic service, the metaslot points to the most appropriate slot, which simplifies the process of selecting a slot. In some cases, a different slot might be required, in which case the application must perform a separate search explicitly. The metaslot is automatically enabled and can only be disabled through explicit action by the system administrator.
A session is a connection between an application that use cryptographic services and a token. The PKCS #11 standard uses two kinds of objects: token objects and session objects. Session objects are ephemeral, that is, objects that last only for the duration of a session. Objects that persist beyond the length of a session are referred to as token objects.
The default location for token objects is $HOME/.sunw/pkcs11_softtoken. Alternatively, token objects can be stored in $SOFTTOKEN_DIR/pkcs11_softtoken. Private token objects are protected by personal identification numbers (PIN). To create or change a token object requires that the user be authenticated, unless the user is accessing a private token object.