NAME    [Toc]    [Back]

       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;

       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.

       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_strdup() 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() and so 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 BUF_strdup() should be freed up
       using the OPENSSL_free() function.

RETURN VALUES    [Toc]    [Back]

       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    [Toc]    [Back]

       bio(3)

HISTORY    [Toc]    [Back]

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


OpenBSD 3.6                 2000-12-14                          2