pam_start(3) — Linux manual page


PAM_START(3)                  Linux-PAM Manual                  PAM_START(3)

NAME         top

       pam_start - initialization of PAM transaction

SYNOPSIS         top

       #include <security/pam_appl.h>

       int pam_start(const char *service_name, const char *user,
                     const struct pam_conv *pam_conversation,
                     pam_handle_t **pamh);

DESCRIPTION         top

       The pam_start function creates the PAM context and initiates the PAM
       transaction. It is the first of the PAM functions that needs to be
       called by an application. The transaction state is contained entirely
       within the structure identified by this handle, so it is possible to
       have multiple transactions in parallel. But it is not possible to use
       the same handle for different transactions, a new one is needed for
       every new context.

       The service_name argument specifies the name of the service to apply
       and will be stored as PAM_SERVICE item in the new context. The policy
       for the service will be read from the file /etc/pam.d/service_name
       or, if that file does not exist, from /etc/pam.conf.

       The user argument can specify the name of the target user and will be
       stored as PAM_USER item. If the argument is NULL, the module has to
       ask for this item if necessary.

       The pam_conversation argument points to a struct pam_conv describing
       the conversation function to use. An application must provide this
       for direct communication between a loaded module and the application.

       Following a successful return (PAM_SUCCESS) the contents of pamh is a
       handle that contains the PAM context for successive calls to the PAM
       functions. In an error case is the content of pamh undefined.

       The pam_handle_t is a blind structure and the application should not
       attempt to probe it directly for information. Instead the PAM library
       provides the functions pam_set_item(3) and pam_get_item(3). The PAM
       handle cannot be used for mulitiple authentications at the same time
       as long as pam_end was not called on it before.

RETURN VALUES         top

           General failure.

           Memory buffer error.

           Transaction was successful created.

           System error, for example a NULL pointer was submitted instead of
           a pointer to data.

SEE ALSO         top

       pam_get_data(3), pam_set_data(3), pam_end(3), pam_strerror(3)

COLOPHON         top

       This page is part of the linux-pam (Pluggable Authentication Modules
       for Linux) project.  Information about the project can be found at 
       ⟨⟩.  If you have a bug report for this manual
       page, see ⟨//⟩.  This page was obtained from the
       tarball Linux-PAM-1.3.0.tar.bz2 fetched from
       ⟨⟩ on 2020-09-18.  If you discover
       any rendering problems in this HTML version of the page, or you
       believe there is a better or more up-to-date source for the page, or
       you have corrections or improvements to the information in this
       COLOPHON (which is not part of the original manual page), send a mail

Linux-PAM Manual                 04/01/2016                     PAM_START(3)

Pages that refer to this page: pam(3)pam_acct_mgmt(3)pam_authenticate(3)pam_chauthtok(3)pam_conv(3)pam_end(3)pam_fail_delay(3)pam_getenv(3)pam_getenvlist(3)pam_get_user(3)pam_putenv(3)pam_xauth_data(3)pam.conf(5)pam.d(5)