---
name: "sasl_client_step"
section: "3"
platform: "linux"
package: "libsasl2-dev"
version: "2.1.28+dfsg1-9"
release: "Debian 13 (Trixie)"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/sasl_client_step"
---

# sasl\_client\_step(3)

Cyrus SASL documentation

## NAME

sasl\_client\_step - Cyrus SASL documentation

## SYNOPSIS

```
#include <sasl/sasl.h>
int sasl_client_step(sasl_conn_t *conn,
               const char *serverin,
               unsigned serverinlen,
               sasl_interact_t ** prompt_need,
               const char ** clientout,
               unsigned * clientoutlen);
```

## DESCRIPTION

- **int sasl\_client\_step(sasl\_conn\_t \*conn,**

  - **const char \*serverin,**

  - **unsigned serverinlen,**

  - **sasl\_interact\_t \*\* prompt\_need,**

  - **const char \*\* clientout,**

  - **unsigned \* clientoutlen);**

  **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).

  - **Parameters**

    - •

      **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*

    - •

      **clientout** – 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) nec‐ essary needs to be done by the client.

    - •

      **clientoutlen** – length of *clientout*.

## RETURN VALUE

SASL  callback  functions should return SASL return codes. See sasl.h for a complete list. *SASL\_CONTINUE* indicates success and that there are more steps needed in the authentication. *SASL\_OK* indicates that the authentication is complete.

Other return codes indicate errors and should either be handled or the authentication session should be quit.

## SEE ALSO

*RFC 4422*,:saslman:*[sasl(3)](/sasl/3.md)*, *[sasl\_callbacks(3)](/sasl_callbacks/3.md)*, *[sasl\_client\_init(3)](/sasl_client_init/3.md)*, *[sasl\_client\_new(3)](/sasl_client_new/3.md)*, *[sasl\_client\_start(3)](/sasl_client_start/3.md)*, *[sasl\_errors(3)](/sasl_errors/3.md)*

## AUTHOR

The Cyrus Team

## COPYRIGHT

1993-2016, The Cyrus Team