SASL_CLIENT_START(3SASL)
Simple Authentication Security Layer Library Functions

NAME

sasl_client_start - perform a step in the authentication negotiation

SYNOPSIS

cc [ flag ... ] file ... -lsasl [ library ... ]
#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

Use the sasl_client_start() interface to select a mechanism for
authentication and start the authentication session. The mechlist
parameter holds the list of mechanisms that the client might like to
use. The mechanisms in the list are not necessarily supported by the
client, nor are the mechanisms necessarily valid. SASL determines
which of the mechanisms to use based upon the security preferences
specified earlier. The list of mechanisms is typically a list of
mechanisms that 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 is filled
in with requests. The application fullfills these requests and calls
sasl_client_start() again with identical parameters. The prompt_need
parameter is the same pointer as before, but it is filled in by the
application.

PARAMETERS

conn
The SASL connection context.


mechlist
A list of mechanism that the server has available.
Punctuation is ignored.


prompt_need
A list of prompts that are needed to continue, if
necessary.


clientout
clientoutlen
clientout and clientoutlen are created. They contain
the initial client response to send to the server. It
is the job of the client to send them over the
network to the server. Any protocol specific
encodingthat is necessary, for example base64
encoding, must 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, upon
success.

RETURN VALUES

sasl_client_start() returns an integer that corresponds to a SASL
error code.

ERRORS

SASL_CONTINUE
The call to sasl_client_start() was successful, and
more steps are needed in the authentication.


All other error codes indicate an error situation that must be
handled, or the authentication session should be quit. See
sasl_errors(3SASL) for information on SASL error codes.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Evolving |
+--------------------+-----------------+
|MT-Level | Safe |
+--------------------+-----------------+

SEE ALSO

sasl_errors(3SASL), attributes(7)

May 13, 2017 SASL_CLIENT_START(3SASL)