NAME

       BUF_MEM_new, BUF_MEM_new_ex, BUF_MEM_free, BUF_MEM_grow, BUF_MEM_grow_clean, BUF_reverse - simple
       character array structure

SYNOPSIS

        #include <openssl/buffer.h>

        BUF_MEM *BUF_MEM_new(void);

        BUF_MEM *BUF_MEM_new_ex(unsigned long flags);

        void BUF_MEM_free(BUF_MEM *a);

        int BUF_MEM_grow(BUF_MEM *str, int len);
        size_t BUF_MEM_grow_clean(BUF_MEM *str, size_t len);

        void BUF_reverse(unsigned char *out, const unsigned char *in, size_t size);

DESCRIPTION

       The buffer library handles simple character arrays. Buffers are used for various purposes in the library,
       most notably memory BIOs.

       BUF_MEM_new() allocates a new buffer of zero size.

       BUF_MEM_new_ex() allocates a buffer with the specified flags.  The flag BUF_MEM_FLAG_SECURE specifies
       that the data pointer should be allocated on the secure heap; see CRYPTO_secure_malloc(3).

       BUF_MEM_free() frees up an already existing buffer. The data is zeroed before freeing up in case the
       buffer contains sensitive data.

       BUF_MEM_grow() changes the size of an already existing buffer to len. Any data already in the buffer is
       preserved if it increases in size.

       BUF_MEM_grow_clean() is similar to BUF_MEM_grow() but it sets any free'd or additionally-allocated memory
       to zero.

       BUF_reverse() reverses size bytes at in into out.  If in is NULL, the array is reversed in-place.

RETURN VALUES

       BUF_MEM_new() returns the buffer or NULL on error.

       BUF_MEM_free() has no return value.

       BUF_MEM_grow() and BUF_MEM_grow_clean() return zero on error or the new size (i.e., len).

SEE ALSO

       bio(7), CRYPTO_secure_malloc(3).

HISTORY

       BUF_MEM_new_ex() was added in OpenSSL 1.1.0.

COPYRIGHT

       Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the OpenSSL license (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>.