Added sending of extra CONNECTION_CLOSE frames. According to quic-transport draft 28 section 10.3.1: When sending CONNECTION_CLOSE, the goal is to ensure that the peer will process the frame. Generally, this means sending the frame in a packet with the highest level of packet protection to avoid the packet being discarded. After the handshake is confirmed (see Section 4.1.2 of [QUIC-TLS]), an endpoint MUST send any CONNECTION_CLOSE frames in a 1-RTT packet. However, prior to confirming the handshake, it is possible that more advanced packet protection keys are not available to the peer, so another CONNECTION_CLOSE frame MAY be sent in a packet that uses a lower packet protection level.

/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_SHA1_H_INCLUDED_
#define _NGX_SHA1_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>


typedef struct {
    uint64_t  bytes;
    uint32_t  a, b, c, d, e, f;
    u_char    buffer[64];
} ngx_sha1_t;


void ngx_sha1_init(ngx_sha1_t *ctx);
void ngx_sha1_update(ngx_sha1_t *ctx, const void *data, size_t size);
void ngx_sha1_final(u_char result[20], ngx_sha1_t *ctx);


#endif /* _NGX_SHA1_H_INCLUDED_ */