<i>sep</i> is the separator between the bytes, setting this to &#39;\0&#39; means that there is no separator. <i>str_n</i> gives the size of the of the string buffer. If <i>strlength</i> is not NULL, it is filled in with the result length. To find out how large the result will be, call this function with NULL for <i>str</i>.</p>

<p>OPENSSL_buf2hexstr() does the same thing as OPENSSL_buf2hexstr_ex(), but allocates the space for the result, and returns the result. It uses a default separator of &#39;:&#39;. 