new file mode 100644
--- /dev/null
+++ b/src/event/quic/ngx_event_quic_openssl_compat.h
@@ -0,0 +1,60 @@
+
+/*
+ * Copyright (C) Nginx, Inc.
+ */
+
+
+#ifndef _NGX_EVENT_QUIC_OPENSSL_COMPAT_H_INCLUDED_
+#define _NGX_EVENT_QUIC_OPENSSL_COMPAT_H_INCLUDED_
+
+#ifdef TLSEXT_TYPE_quic_transport_parameters
+#undef NGX_QUIC_OPENSSL_COMPAT
+#else
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+
+
+typedef struct ngx_quic_compat_s  ngx_quic_compat_t;
+
+
+enum ssl_encryption_level_t {
+    ssl_encryption_initial = 0,
+    ssl_encryption_early_data,
+    ssl_encryption_handshake,
+    ssl_encryption_application
+};
+
+
+typedef struct ssl_quic_method_st {
+    int (*set_read_secret)(SSL *ssl, enum ssl_encryption_level_t level,
+                           const SSL_CIPHER *cipher,
+                           const uint8_t *rsecret, size_t secret_len);
+    int (*set_write_secret)(SSL *ssl, enum ssl_encryption_level_t level,
+                            const SSL_CIPHER *cipher,
+                            const uint8_t *wsecret, size_t secret_len);
+    int (*add_handshake_data)(SSL *ssl, enum ssl_encryption_level_t level,
+                              const uint8_t *data, size_t len);
+    int (*flush_flight)(SSL *ssl);
+    int (*send_alert)(SSL *ssl, enum ssl_encryption_level_t level,
+                      uint8_t alert);
+} SSL_QUIC_METHOD;
+
+
+ngx_int_t ngx_quic_compat_init(ngx_conf_t *cf, SSL_CTX *ctx);
+
+int SSL_set_quic_method(SSL *ssl, const SSL_QUIC_METHOD *quic_method);
+int SSL_provide_quic_data(SSL *ssl, enum ssl_encryption_level_t level,
+    const uint8_t *data, size_t len);
+enum ssl_encryption_level_t SSL_quic_read_level(const SSL *ssl);
+enum ssl_encryption_level_t SSL_quic_write_level(const SSL *ssl);
+int SSL_set_quic_transport_params(SSL *ssl, const uint8_t *params,
+    size_t params_len);
+void SSL_get_peer_quic_transport_params(const SSL *ssl,
+    const uint8_t **out_params, size_t *out_params_len);
+
+
+#endif /* TLSEXT_TYPE_quic_transport_parameters */
+
+#endif /* _NGX_EVENT_QUIC_OPENSSL_COMPAT_H_INCLUDED_ */