.ptr</span> <span>&#45;&gt;</span> Unsigned.size_t</code></dt><dd><p><code>sha256_length util</code></p><p>The length of the buffer needed to hold the SHA-256 hash.</p></dd></dl><dl><dt class="spec value" id="val-sha256"><a href="#val-sha256" class="anchor"></a><code><span class="keyword">val</span> sha256 : <span><a href="../Types/Utility/index.html#type-t">Types.Utility.t</a> Ctypes_static.ptr</span> <span>&#45;&gt;</span> <span>unit Ctypes_static.ptr</span> <span>&#45;&gt;</span> Unsigned.size_t <span>&#