include/openssl/buf.h

// Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef OPENSSL_HEADER_BUFFER_H
#define OPENSSL_HEADER_BUFFER_H

#include <openssl/base.h>   // IWYU pragma: export

#if defined(__cplusplus)
extern "C" {
#endif


// Memory and string functions, see also mem.h.


// buf_mem_st (aka `BUF_MEM`) is a generic buffer object used by OpenSSL.
struct buf_mem_st {
  size_t length;  // current number of bytes
  char *data;
  size_t max;  // size of buffer
};

// BUF_MEM_new creates a new BUF_MEM which has no allocated data buffer.
OPENSSL_EXPORT BUF_MEM *BUF_MEM_new(void);

// BUF_MEM_free frees `buf->data` if needed and then frees `buf` itself.
OPENSSL_EXPORT void BUF_MEM_free(BUF_MEM *buf);

// BUF_MEM_reserve ensures `buf` has capacity `cap` and allocates memory if
// needed. It returns one on success and zero on error.
OPENSSL_EXPORT int BUF_MEM_reserve(BUF_MEM *buf, size_t cap);

// BUF_MEM_grow ensures that `buf` has length `len` and allocates memory if
// needed. If the length of `buf` increased, the new bytes are filled with
// zeros. It returns the length of `buf`, or zero if there's an error.
OPENSSL_EXPORT size_t BUF_MEM_grow(BUF_MEM *buf, size_t len);

// BUF_MEM_grow_clean calls `BUF_MEM_grow`. BoringSSL always zeros memory
// allocated memory on free.
OPENSSL_EXPORT size_t BUF_MEM_grow_clean(BUF_MEM *buf, size_t len);

// BUF_MEM_append appends `in` to `buf`. It returns one on success and zero on
// error.
OPENSSL_EXPORT int BUF_MEM_append(BUF_MEM *buf, const void *in, size_t len);


// Deprecated functions.

// BUF_strdup calls `OPENSSL_strdup`.
OPENSSL_EXPORT char *BUF_strdup(const char *str);

// BUF_strnlen calls `OPENSSL_strnlen`.
OPENSSL_EXPORT size_t BUF_strnlen(const char *str, size_t max_len);

// BUF_strndup calls `OPENSSL_strndup`.
OPENSSL_EXPORT char *BUF_strndup(const char *str, size_t size);

// BUF_memdup calls `OPENSSL_memdup`.
OPENSSL_EXPORT void *BUF_memdup(const void *data, size_t size);

// BUF_strlcpy calls `OPENSSL_strlcpy`.
OPENSSL_EXPORT size_t BUF_strlcpy(char *dst, const char *src, size_t dst_size);

// BUF_strlcat calls `OPENSSL_strlcat`.
OPENSSL_EXPORT size_t BUF_strlcat(char *dst, const char *src, size_t dst_size);


#if defined(__cplusplus)
}  // extern C

extern "C++" {

BSSL_NAMESPACE_BEGIN

BORINGSSL_MAKE_DELETER(BUF_MEM, BUF_MEM_free)

BSSL_NAMESPACE_END

}  // extern C++

#endif

#endif  // OPENSSL_HEADER_BUFFER_H