NAME

       BIO_new_ex, BIO_new, BIO_up_ref, BIO_free, BIO_vfree, BIO_free_all - BIO allocation and
       freeing functions

SYNOPSIS

        #include <openssl/bio.h>

        BIO *BIO_new_ex(OSSL_LIB_CTX *libctx, const BIO_METHOD *type);
        BIO *BIO_new(const BIO_METHOD *type);
        int BIO_up_ref(BIO *a);
        int BIO_free(BIO *a);
        void BIO_vfree(BIO *a);
        void BIO_free_all(BIO *a);

DESCRIPTION

       The BIO_new_ex() function returns a new BIO using method type associated with the library
       context libctx (see OSSL_LIB_CTX(3)). The library context may be NULL to indicate the
       default library context.

       The BIO_new() is the same as BIO_new_ex() except the default library context is always
       used.

       BIO_up_ref() increments the reference count associated with the BIO object.

       BIO_free() frees up a single BIO, BIO_vfree() also frees up a single BIO but it does not
       return a value.  If a is NULL nothing is done.  Calling BIO_free() may also have some
       effect on the underlying I/O structure, for example it may close the file being referred
       to under certain circumstances. For more details see the individual BIO_METHOD
       descriptions.

       BIO_free_all() frees up an entire BIO chain, it does not halt if an error occurs freeing
       up an individual BIO in the chain.  If a is NULL nothing is done.

RETURN VALUES

       BIO_new_ex() and BIO_new() return a newly created BIO or NULL if the call fails.

       BIO_up_ref() and BIO_free() return 1 for success and 0 for failure.

       BIO_free_all() and BIO_vfree() do not return values.

NOTES

       If BIO_free() is called on a BIO chain it will only free one BIO resulting in a memory
       leak.

       Calling BIO_free_all() on a single BIO has the same effect as calling BIO_free() on it
       other than the discarded return value.

HISTORY

       BIO_set() was removed in OpenSSL 1.1.0 as BIO type is now opaque.

       BIO_new_ex() was added in OpenSSL 3.0.

EXAMPLES

       Create a memory BIO:

        BIO *mem = BIO_new(BIO_s_mem());

COPYRIGHT

       Copyright 2000-2021 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>.