+/*
+ * A callback for logging out TLS key material. This callback should log out
+ * |line| followed by a newline.
+ */
+typedef void (*SSL_CTX_keylog_cb_func)(const SSL *ssl, const char *line);
+
+/*
+ * SSL_CTX_set_keylog_callback configures a callback to log key material. This
+ * is intended for debugging use with tools like Wireshark. The cb function
+ * should log line followed by a newline.
+ */
+void SSL_CTX_set_keylog_callback(SSL_CTX *ctx, SSL_CTX_keylog_cb_func cb);
+
+/*
+ * SSL_CTX_get_keylog_callback returns the callback configured by
+ * SSL_CTX_set_keylog_callback.
+ */
+SSL_CTX_keylog_cb_func SSL_CTX_get_keylog_callback(const SSL_CTX *ctx);
+