+
+
+void
+Socket::start_read_digest ()
+{
+ DCPOMATIC_ASSERT (!_read_digester);
+ _read_digester.reset (new Digester());
+}
+
+void
+Socket::start_write_digest ()
+{
+ DCPOMATIC_ASSERT (!_write_digester);
+ _write_digester.reset (new Digester());
+}
+
+
+Socket::ReadDigestScope::ReadDigestScope (shared_ptr<Socket> socket)
+ : _socket (socket)
+{
+ socket->start_read_digest ();
+}
+
+
+bool
+Socket::ReadDigestScope::check ()
+{
+ shared_ptr<Socket> sp = _socket.lock ();
+ if (!sp) {
+ return false;
+ }
+
+ return sp->check_read_digest ();
+}
+
+
+Socket::WriteDigestScope::WriteDigestScope (shared_ptr<Socket> socket)
+ : _socket (socket)
+{
+ socket->start_write_digest ();
+}
+
+
+Socket::WriteDigestScope::~WriteDigestScope ()
+{
+ shared_ptr<Socket> sp = _socket.lock ();
+ if (sp) {
+ try {
+ sp->finish_write_digest ();
+ } catch (...) {
+ /* If we can't write our digest, something bad has happened
+ * so let's just let it happen.
+ */
+ }
+ }
+}
+
+
+bool
+Socket::check_read_digest ()
+{
+ DCPOMATIC_ASSERT (_read_digester);
+ int const size = _read_digester->size ();
+
+ uint8_t ref[size];
+ _read_digester->get (ref);
+
+ /* Make sure _read_digester is gone before we call read() so that the digest
+ * isn't itself digested.
+ */
+ _read_digester.reset ();
+
+ uint8_t actual[size];
+ read (actual, size);
+
+ return memcmp(ref, actual, size) == 0;
+}
+
+void
+Socket::finish_write_digest ()
+{
+ DCPOMATIC_ASSERT (_write_digester);
+ int const size = _write_digester->size();
+
+ uint8_t buffer[size];
+ _write_digester->get (buffer);
+
+ /* Make sure _write_digester is gone before we call write() so that the digest
+ * isn't itself digested.
+ */
+ _write_digester.reset ();
+
+ write (buffer, size);
+}
+