sasl_client_step() performs a step in the authentication negotiation. It returns SASL_OK
if the whole negotiation is successful and SASL_CONTINUE if this step
is ok but at least one more step is needed. A client should not assume
an authentication negotiation is successful just because the server
signaled success via protocol (i.e. if the server said ". OK
Authentication succeeded" in IMAP sasl_client_step should still be
called one more time with a serverinlen of zero.
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).
conn is the SASL connection context
serverin is the data given by the server (decoded if the protocol encodes requests sent over the wire)
serverinlen is the length of serverin
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.