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)