kg_allocate_iov
krb5_error_code kg_allocate_iov(gss_iov_buffer_t iov, size_t size);
code = kg_allocate_iov(header, k5_headerlen);
code = kg_allocate_iov(padding, gss_padlen);
code = kg_allocate_iov(header, (size_t) gss_headerlen);
code = kg_allocate_iov(trailer, (size_t) gss_trailerlen);
code = kg_allocate_iov(header, (size_t) gss_headerlen);
code = kg_allocate_iov(trailer, (size_t) gss_trailerlen);
code = kg_allocate_iov(tdata, tdata->buffer.length);