pam_start.3 (2010 09)

pam_start(3) pam_start(3)

The maximum size of the message and the response string is

PAM_MAX_MSG_SIZE

deﬁned in

The structure pam_response is used by the authentication service to get the user’s response back from the

application or user. The storage used by pam_response has to be allocated by the application and freed

by the PAM modules. The pam_response structure has the following entries:

struct pam_response{

char *resp;

int resp_retcode; /* currently not used, should be set to 0 */

};

It is the responsibility of the conversation function to strip off newline characters for

PAM_PROMPT_ECHO_OFF

and PAM_PROMPT_ECHO_ON

message styles, and to add newline characters

(if appropriate) for

PAM_ERROR_MSG

and PAM_TEXT_INFO

message styles.

appdata_ptr is an application data pointer which is passed by the application to the PAM service

modules. Since the PAM modules pass it back through the conversation function, the applications can

use this pointer to point to any application-speciﬁc data.

pam_end() is called to terminate the authentication transaction identiﬁed by pamh and to free any

storage area allocated by the authentication module. The argument, status , is passed to the

cleanup()

function stored within the pam handle, and is used to determine what module speciﬁc state must be

purged. A cleanup function is attached to the handle by the underlying PAM modules through a call to

pam_set_item (3) to free module speciﬁc data.

APPLICATION USAGE

Refer to pam(3) for information on thread-safety of PAM interfaces.

RETURN VALUE

Refer to pam(3) for information on error related return values.