GSS-API Data Types and Values

This section describes various types of GSS-API data types and values. Some data types, such as gss_cred_id_t or gss_name_t, are opaque to the user. These data types do not need to be discussed. This section explains the following topics:

• Basic GSS-API Data Types – Shows the definitions of the OM_uint32, gss_buffer_desc, gss_OID_desc, gss_OID_set_desc_struct, and gss_channel_bindings_struct data types.

• Name Types – Shows the various name formats recognized by the GSS-API for specifying names.

• Address Types for Channel Bindings – Shows the various values that can be used as the initiator_addrtype and acceptor_addrtype fields of the gss_channel_bindings_t structure.

Basic GSS-API Data Types

This section describes data types that are used by GSS-API.

OM_uint32

The OM_uint32 is a platform-independent 32–bit unsigned integer.

gss_buffer_desc

The definition of the gss_buffer_desc with the gss_buffer_t pointer takes the following form:

typedef struct gss_buffer_desc_struct {
        size_t length;
        void *value;
} gss_buffer_desc, *gss_buffer_t;

gss_OID_desc

The definition of the gss_OID_desc with the gss_OID pointer takes the following form:

typedef struct gss_OID_desc_struct {
        OM_uint32 length;
        void*elements;
} gss_OID_desc, *gss_OID;

gss_OID_set_desc

The definition of the gss_OID_set_desc with the gss_OID_set pointer takes the following form:

typedef struct gss_OID_set_desc_struct  {
        size_t  count;
        gss_OID elements;
} gss_OID_set_desc, *gss_OID_set;

gss_channel_bindings_struct

The definition of the gss_channel_bindings_struct structure and the gss_channel_bindings_t pointer has the following form:

typedef struct gss_channel_bindings_struct {
        OM_uint32 initiator_addrtype;
        gss_buffer_desc initiator_address;
        OM_uint32 acceptor_addrtype;
        gss_buffer_desc acceptor_address;
        gss_buffer_desc application_data;
} *gss_channel_bindings_t;

Name Types

A name type indicates the format of the associated name. See Names in GSS-API and GSS-API OIDs for more on names and name types. The GSS-API supports the gss_OID name types in the following table.

GSS_C_NO_NAME

The symbolic name GSS_C_NO_NAME is recommended as a parameter value to indicate that no value is supplied in the transfer of names.

GSS_C_NO_OID

This value corresponds to a null input value instead of an actual object identifier. Where specified, the value indicates interpretation of an associated name that is based on a mechanism-specific default printable syntax.

GSS_C_NT_ANONYMOUS

A means to identify anonymous names. This value can be compared with to determine in a mechanism-independent fashion whether a name refers to an anonymous principal.

GSS_C_NT_EXPORT_NAME

A name that has been exported with the gss_export_name() function.

GSS_C_NT_HOSTBASED_SERVICE

Used to represent services that are associated with host computers. This name form is constructed using two elements, service and hostname, as follows: service@hostname.

GSS_C_NT_MACHINE_UID_NAME

Used to indicate a numeric user identifier corresponding to a user on a local system. The interpretation of this value is OS-specific. The gss_import_name() function resolves this UID into a user name, which is then treated as the User Name Form.

GSS_C_NT_STRING_STRING_UID_NAME

Used to indicate a string of digits that represents the numeric user identifier of a user on a local system. The interpretation of this value is OS-specific. This name type is similar to the Machine UID Form, except that the buffer contains a string that represents the user ID.

GSS_C_NT_USER_NAME

A named user on a local system. The interpretation of this value is OS-specific. The value takes the form: username.

Address Types for Channel Bindings

The following table shows the possible values for the initiator_addrtype and acceptor_addrtype fields of the gss_channel_bindings_struct structure. These fields indicate the format that a name can take, for example, ARPAnet IMP address or AppleTalk address. Channel bindings are discussed in Using Channel Bindings in GSS-API.

Table C-4 Channel Binding Address Types