DOKK / manpages / debian 10 / libsasl2-dev / sasl_server_start.3.en
SASL_SERVER_START(3) Cyrus SASL SASL_SERVER_START(3)

sasl_server_start - Cyrus SASL documentation

#include <sasl/sasl.h>
int sasl_server_start(sasl_conn_t * conn,

const char * mech,
const char * clientin,
unsigned clientinlen,
const char ** serverout,
unsigned * serveroutlen);

sasl_server_start() begins the authentication with the mechanism specified with mech. This fails if the mechanism is not supported.
  • conn – is the SASL connection context
  • mech – is the mechanism name that the client requested
  • clientin – is the client initial response, NULL if the protocol lacks support for client‐send‐first or if the other end did not have an initial send. Note that no initial client send is distinct from an initial send of a null string, and the protocol MUST account for this difference.
  • clientinlen – is the length of initial response
  • serverout – is created by the plugin library. It is the initial server response to send to the client. This is allocated/freed by the library and it is the job of the client to send it over the network to the server. Also protocol specific encoding (such as base64 encoding) must needs to be done by the server.
  • serveroutlen – is set to the length of initial server challenge



SASL callback functions should return SASL return codes. See sasl.h for a complete list. SASL_OK is returned if the authentication is complete and the user is authenticated. SASL_CONTINUE is returned if one or more steps are still required in the authentication.

All other return values indicate errors and should be handled or the authentication session should be quit.

RFC 4422,:saslman:sasl(3), sasl_server_init(3), sasl_server_new(3), sasl_server_step(3), sasl_errors(3)

The Cyrus Team

1993-2022, The Cyrus Team

February 25, 2022 2.1.27