 written through the filter is used verbatim: no canonical translation is performed.</p>

<p>It is possible to chain multiple BIOs to, for example, create a triple wrapped signed, enveloped, signed structure. In this case it is the applications responsibility to set the inner content type of any outer CMS_ContentInfo structures.</p>

<p>Large numbers of small writes through the chain should be avoided as this will produce an output consisting of lots of OCTET STRING structures. Prepending a BIO_f_buffer() b