# pam_start(3) - phpMan

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



**NAME**
       pam_start, pam_start_confdir - initialization of PAM transaction

**SYNOPSIS**
       **#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_**);**

       **int** **pam**___**start**___**confdir(const** **char** *****_service_name_**,** **const** **char** *****_user_**,**
                             **const** **struct** **pam**___**conv** *****_pam_conversation_**,**
                             **const** **char** *****_confdir_**,** **pam**___**handle**___**t** ******_pamh_**);**

**DESCRIPTION**
       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 multiple authentications at the same time as
       long as **pam**___**end** was not called on it before.

       The **pam**___**start**___**confdir** function behaves like the **pam**___**start** function but
       it also allows setting _confdir_ argument with a path to a directory to
       override the default (/etc/pam.d) path for service policy files. If the
       _confdir_ is NULL, the function works exactly the same as **pam**___**start**.

**RETURN** **VALUES**
       PAM_ABORT
           General failure.

       PAM_BUF_ERR
           Memory buffer error.

       PAM_SUCCESS
           Transaction was successfully started.

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

**SEE** **ALSO**
       **pam**___**get**___**[data**(3)], **pam**___**set**___**[data**(3)], **pam**___**[end**(3)], **pam**___**[strerror**(3)]



Linux-PAM Manual                  06/08/2020                      [PAM_START(3)]