NAME    [Toc]    [Back]

       buffer,     BUF_MEM_new,    BUF_MEM_free,    BUF_MEM_grow,
       BUF_strdup - Simple character arrays structure

SYNOPSIS    [Toc]    [Back]

       #include <openssl/buffer.h>

       BUF_MEM *BUF_MEM_new(
               void ); void BUF_MEM_free(
               BUF_MEM *a ); int   BUF_MEM_grow(
               BUF_MEM *str, int len ); char * BUF_strdup(
               const char *str );

DESCRIPTION    [Toc]    [Back]

       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
        {
               int length;     /* current number of bytes */
               char *data;
               int max;        /* size of buffer */
        } BUF_MEM;

       The 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.

       The BUF_MEM_new() function allocates a new buffer of  zero
       size.

       The  BUF_MEM_free()  function frees up an already existing
       buffer. The data is zeroed before freeing up in  case  the
       buffer contains sensitive data.

       The BUF_MEM_grow() function changes the size of an already
       existing buffer to len. Any data already in the buffer  is
       preserved if it increases in size.

       The  BUF_strdup() function copies a null terminated string
       into a block of allocated memory and returns a pointer  to
       the   allocated  block.  Unlike  the  standard  C  library
       strdup(), this function uses OPENSSL_malloc().  It  should
       be  used  in  preference  to the standard library strdup()
       because it can be used for memory leak checking or replacing
 the malloc() function.

       The memory allocated from the BUF_strdup() function should
       be freed up using the OPENSSL_free() function.

RETURN VALUES    [Toc]    [Back]

       The BUF_MEM_new() function returns the buffer or  NULL  on
       error.

       The BUF_MEM_free() function has no return value.

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

HISTORY    [Toc]    [Back]

       The  BUF_MEM_new(),  BUF_MEM_free(),  and   BUF_MEM_grow()
       functions  are  available  in  all  versions of SSLeay and
       OpenSSL. The BUF_strdup() function  was  added  in  SSLeay
       0.8.

SEE ALSO    [Toc]    [Back]

       Function: bio(3)



                                                        buffer(3)