NAME

       sasl_client_start - Begin an authentication negotiation

SYNOPSIS

       #include <sasl/sasl.h>

       int sasl_client_start(sasl_conn_t * conn,
                       const char * mechlist,
                       sasl_interact_t ** prompt_need,
                       const char ** clientout,
                       unsigned * clientoutlen,
                       const char ** mech);

DESCRIPTION

       sasl_client_start()  selects  a mechanism for authentication and starts the authentication
       session. The mechlist is the list  of  mechanisms  the  client  might  like  to  use.  The
       mechanisms  in  the  list  are not necessarily supported by the client or even valid. SASL
       determines which of these to use based upon the security  preferences  specified  earlier.
       The list of mechanisms is typically a list of mechanisms the server supports acquired from
       a capability request.

       If SASL_INTERACT is returned the library needs some values to be filled in before  it  can
       proceed. The prompt_need structure will be filled in with requests. The application should
       fulfill these requests and call sasl_client_start again  with  identical  parameters  (the
       prompt_need  parameter  will  be  the  same  pointer  as  before  but  filled  in  by  the
       application).

       mechlist is a list of mechanisms the server has available. Punctuation is ignored.

       prompt_need is filled in with a list of prompts needed to continue (if necessary).

       clientout and clientoutlen is created. It is the initial client response to  send  to  the
       server.  It  is  the  job  of  the  client to send it over the network to the server.  Any
       protocol specific encoding (such as base64 encoding) necessary needs to  be  done  by  the
       client.

       If the protocol lacks client-send-first capability, then set clientout to NULL.

       If there is no initial client-send, then *clientout will be set to NULL on return.

       mech contains the name of the chosen SASL mechanism (on success)

RETURN VALUE

       sasl_client_start  returns  an  integer  which  corresponds to one of the following codes.
       SASL_CONTINUE  indicates  success  and  that  there  are  more   steps   needed   in   the
       authentication. All other return codes indicate errors and should either be handled or the
       authentication session should be quit.

CONFORMING TO

       RFC 4422

SEE ALSO

       sasl(3),  sasl_callbacks(3),  sasl_errors(3),   sasl_client_init(3),   sasl_client_new(3),
       sasl_client_step(3)