libressl-BUF_MEM_new3
Simple character arrays structure
Usage
Crypto Library (libcrypto, -lcrypto)
#include <openssl/buffer.h>
BUF_MEM *
BUF_MEM_new(void);
void
BUF_MEM_free(BUF_MEM *a);
int
BUF_MEM_grow(BUF_MEM *str, size_t len);
int
BUF_MEM_grow_clean(BUF_MEM *str, size_t len);
Overview
The buffer library handles simple character arrays. Buffers are used for various purposes in the library, most notably memory BIOs.
The library uses the BUF_MEM structure defined in buffer.h:
typedef struct buf_mem_st {
size_t length; /* current number of bytes */
char *data;
size_t max; /* size of buffer */
} BUF_MEM;
length is the current size of the buffer in bytes; max is the amount of memory allocated to the buffer. There are three functions which handle these and one miscellaneous function.
BUF_MEM_new() allocates a new buffer of zero size.
BUF_MEM_free() frees up an already existing buffer. The data is zeroed before freeing up in case the buffer contains sensitive data. If a is a NULL pointer, no action occurs.
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 freed or additionally allocated memory to zero.
Return values
BUF_MEM_new() returns the buffer or NULL on error.
BUF_MEM_grow() and BUF_MEM_grow_clean() return zero on error or the new size (i.e. len).