BUF_MEM_new(3ssl)

BUF_MEM_new3ssl

Simple character array structure

Usage

 #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);

Overview

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. If the argument is NULL, nothing is done.

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).

Releases

12 releases since Debian 3.1 (Sarge); the text changed 11 times.

  1. 3.1
  2. 4.0
  3. 5.0
  4. 6.0
  5. 7
  6. 8
  7. 9
  8. 10
  9. 11
  10. 12
  11. 13
  12. Arch

History

The BUF_MEM_new_ex() function was added in OpenSSL 1.1.0.

From openssl 3.6.5-1 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.