+# ifndef OPENSSL_NO_SOCK
+int DTLSv1_listen(SSL *s, BIO_ADDR *client);
+# endif
+
+# ifndef OPENSSL_NO_CT
+
+/*
+ * A callback for verifying that the received SCTs are sufficient.
+ * Expected to return 1 if they are sufficient, otherwise 0.
+ * May return a negative integer if an error occurs.
+ * A connection should be aborted if the SCTs are deemed insufficient.
+ */
+typedef int(*ssl_ct_validation_cb)(const CT_POLICY_EVAL_CTX *ctx,
+ const STACK_OF(SCT) *scts, void *arg);
+
+/*
+ * Sets a |callback| that is invoked upon receipt of ServerHelloDone to validate
+ * the received SCTs.
+ * If the callback returns a non-positive result, the connection is terminated.
+ * Call this function before beginning a handshake.
+ * If a NULL |callback| is provided, SCT validation is disabled.
+ * |arg| is arbitrary userdata that will be passed to the callback whenever it
+ * is invoked. Ownership of |arg| remains with the caller.
+ *
+ * NOTE: A side-effect of setting a CT callback is that an OCSP stapled response
+ * will be requested.
+ */
+int SSL_set_ct_validation_callback(SSL *s, ssl_ct_validation_cb callback,
+ void *arg);
+int SSL_CTX_set_ct_validation_callback(SSL_CTX *ctx,
+ ssl_ct_validation_cb callback,
+ void *arg);
+#define SSL_disable_ct(s) \
+ ((void) SSL_set_validation_callback((s), NULL, NULL))
+#define SSL_CTX_disable_ct(ctx) \
+ ((void) SSL_CTX_set_validation_callback((ctx), NULL, NULL))
+
+/*
+ * The validation type enumerates the available behaviours of the built-in SSL
+ * CT validation callback selected via SSL_enable_ct() and SSL_CTX_enable_ct().
+ * The underlying callback is a static function in libssl.
+ */
+enum {
+ SSL_CT_VALIDATION_PERMISSIVE = 0,
+ SSL_CT_VALIDATION_STRICT
+};
+
+/*
+ * Enable CT by setting up a callback that implements one of the built-in
+ * validation variants. The SSL_CT_VALIDATION_PERMISSIVE variant always
+ * continues the handshake, the application can make appropriate decisions at
+ * handshake completion. The SSL_CT_VALIDATION_STRICT variant requires at
+ * least one valid SCT, or else handshake termination will be requested. The
+ * handshake may continue anyway if SSL_VERIFY_NONE is in effect.
+ */
+int SSL_enable_ct(SSL *s, int validation_mode);
+int SSL_CTX_enable_ct(SSL_CTX *ctx, int validation_mode);
+
+/*
+ * Report whether a non-NULL callback is enabled.
+ */
+int SSL_ct_is_enabled(const SSL *s);
+int SSL_CTX_ct_is_enabled(const SSL_CTX *ctx);
+
+/* Gets the SCTs received from a connection */
+const STACK_OF(SCT) *SSL_get0_peer_scts(SSL *s);
+
+/*
+ * Loads the CT log list from the default location.
+ * If a CTLOG_STORE has previously been set using SSL_CTX_set_ctlog_store,
+ * the log information loaded from this file will be appended to the
+ * CTLOG_STORE.
+ * Returns 1 on success, 0 otherwise.
+ */
+int SSL_CTX_set_default_ctlog_list_file(SSL_CTX *ctx);
+
+/*
+ * Loads the CT log list from the specified file path.
+ * If a CTLOG_STORE has previously been set using SSL_CTX_set_ctlog_store,
+ * the log information loaded from this file will be appended to the
+ * CTLOG_STORE.
+ * Returns 1 on success, 0 otherwise.
+ */
+int SSL_CTX_set_ctlog_list_file(SSL_CTX *ctx, const char *path);
+
+/*
+ * Sets the CT log list used by all SSL connections created from this SSL_CTX.
+ * Ownership of the CTLOG_STORE is transferred to the SSL_CTX.
+ */
+void SSL_CTX_set0_ctlog_store(SSL_CTX *ctx, CTLOG_STORE *logs);
+
+/*
+ * Gets the CT log list used by all SSL connections created from this SSL_CTX.
+ * This will be NULL unless one of the following functions has been called:
+ * - SSL_CTX_set_default_ctlog_list_file
+ * - SSL_CTX_set_ctlog_list_file
+ * - SSL_CTX_set_ctlog_store
+ */
+const CTLOG_STORE *SSL_CTX_get0_ctlog_store(const SSL_CTX *ctx);
+
+# endif /* OPENSSL_NO_CT */
+