pam_set_data

3 Linux-PAM Linux-PAM Manual

pam_set_data

set module internal data

         #include <security/pam_modules.h>

           int pam_set_data
           pam_handle_t *pamh
           const char *module_data_name
           void *data
           void (*cleanup)(pam_handle_t *pamh, void *data, int error_status)

## DESCRIPTION

The `pam_set_data` function associates a pointer to an object with the (hopefully) unique string module_data_name in the PAM context specified by the pamh argument.

PAM modules may be dynamically loadable objects. In general such files should not contain static variables. This function and its counterpart

pam_get_data

3 , provide a mechanism for a module to associate some data with the handle pamh. Typically a module will call the `pam_set_data` function to register some data under a (hopefully) unique module_data_name. The data is available for use by other modules too but not by an application. Since this functions stores only a pointer to the data, the module should not modify or free the content of it.

The function `cleanup()` is associated with the data and, if non-NULL, it is called when this data is over-written or following a call to

pam_end

3 .

The error_status argument is used to indicate to the module the sort of action it is to take in cleaning this data item. As an example, Kerberos creates a ticket file during the authentication phase, this file might be associated with a data item. When

pam_end

3 is called by the module, the error_status carries the return value of the

pam_authenticate

3 or other libpam function as appropriate. Based on this value the Kerberos module may choose to delete the ticket file (authentication failure) or leave it in place.

The error_status may have been logically OR'd with either of the following two values:

PAM_DATA_REPLACE

- When a data item is being replaced (through a second call to `pam_set_data`) this mask is used. Otherwise, the call is assumed to be from

  pam_end

  3 .

PAM_DATA_SILENT

- Which indicates that the process would prefer to perform the `cleanup()` quietly. That is, discourages logging/messages to the user. It is generally used to indicate that the current closing of the library is in a

  fork

  2 ed process, and that the parent will take care of cleaning up things that exist outside of the current process space (files etc.).

## RETURN VALUES

PAM_BUF_ERR

- Memory buffer error.

PAM_SUCCESS

- Data was successful stored.

PAM_SYSTEM_ERR

- A NULL pointer was submitted as PAM handle or the function was called by an application.

## SEE ALSO

pam_end

3 ,

pam_get_data

3 ,

pam_strerror

3