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

       The BUF_MEM_new_ex() function was added in OpenSSL 1.1.0.

COPYRIGHT

       Copyright 2000-2018 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>.