BUF_MEM_NEW(3)

💖 BUF_MEM_NEW(3) 💖

okay so welcome to the BUF_MEM_NEW(3) page from the Library Functions Manual — yes, the manual name is folded right in here, bestie, because we are not doing boring header-line energy today. This is the buffer-memory page: simple character arrays, but make it libcrypto. ✨

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🌸 NAME 🌸

BUF_MEM_new, BUF_MEM_free, BUF_MEM_grow, BUF_MEM_grow_clean — simple character arrays structure, and honestly that's the whole vibe.

✨ SYNOPSIS ✨

library “libcrypto” #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);

🎀 DESCRIPTION 🎀

The buffer library handles simple character arrays. Buffers are used for various purposes in the library, most notably memory BIOs. iykyk — memory BIOs are lowkey the main character here.

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 — that's the official count, periodt.

• BUF_MEM_new() — allocates a new buffer of zero size. Main character move: it arrives empty and ready to grow.
• 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. Security queen behavior, fr fr.
• 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).

🔥 SEE ALSO 🔥

• BIO_new(3)
• BIO_s_mem(3)

Go read these too, bestie — they're giving related lore. 💅

🦋 HISTORY 🦋

• BUF_MEM_new(), BUF_MEM_free(), and BUF_MEM_grow() first appeared in SSLeay 0.6.0. All these functions have been available since OpenBSD 2.4.
• BUF_MEM_grow_clean() first appeared in OpenSSL 0.9.7 and has been available since OpenBSD 3.2.

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xoxo, your Debian bestie 💖 — this page is dated June 8, 2025, and it's the BUF_MEM_NEW(3) page. Slay. ✨🎀🦋