NAME

       SSL_free_buffers, SSL_alloc_buffers - manage SSL structure buffers

SYNOPSIS

        #include <openssl/ssl.h>

        int SSL_free_buffers(SSL *ssl);
        int SSL_alloc_buffers(SSL *ssl);

DESCRIPTION

       SSL_free_buffers() frees the read and write buffers of the given ssl.  SSL_alloc_buffers() allocates the
       read and write buffers of the given ssl.

       The SSL_MODE_RELEASE_BUFFERS mode releases read or write buffers whenever the buffers have been drained.
       These functions allow applications to manually control when buffers are freed and allocated.

       After freeing the buffers, the buffers are automatically reallocated upon a new read or write. The
       SSL_alloc_buffers() does not need to be called, but can be used to make sure the buffers are
       preallocated. This can be used to avoid allocation during data processing or with
       CRYPTO_set_mem_functions() to control where and how buffers are allocated.

RETURN VALUES

       The following return values can occur:

       0 (Failure)
           The  SSL_free_buffers()  function  returns  0  when  there is pending data to be read or written. The
           SSL_alloc_buffers() function returns 0 when there is an allocation failure.

       1 (Success)
           The SSL_free_buffers() function returns 1 if the buffers have been freed. This value is also returned
           if the buffers had been freed before calling SSL_free_buffers().   The  SSL_alloc_buffers()  function
           returns  1  if  the buffers have been allocated.  This value is also returned if the buffers had been
           allocated before calling SSL_alloc_buffers().

SEE ALSO

       ssl(7), SSL_free(3), SSL_clear(3), SSL_new(3), SSL_CTX_set_mode(3), CRYPTO_set_mem_functions(3)

COPYRIGHT

       Copyright 2017-2020 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the Apache License 2.0 (the "License").  You may not use this file  except  in  compliance
       with  the  License.   You  can  obtain  a  copy  in  the  file  LICENSE  in the source distribution or at
       <https://www.openssl.org/source/license.html>.

3.0.13                                             2025-09-18                            SSL_ALLOC_BUFFERS(3SSL)