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>.