OpenSSL

Cryptography and SSL/TLS Toolkit

buffer

NAME

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

standard C library equivalents

SYNOPSIS

 #include <openssl/buffer.h>

 BUF_MEM *BUF_MEM_new(void);

 #define BUF_MEM_FLAG_SECURE

 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);

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.

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.

RETURN VALUES

BUF_MEM_new() returns the buffer or NULL on error.

BUF_MEM_free() has no return value.

BUF_MEM_grow() returns zero on error or the new size (i.e. len).

SEE ALSO

bio, CRYPTO_secure_malloc.

HISTORY

BUF_MEM_new_ex() was added in OpenSSL 1.1.0.