SSL: ssl_reject_handshake directive (ticket #195). In some cases it might be needed to reject SSL handshake based on SNI server name provided, for example, to make sure an invalid certificate is not returned to clients trying to contact a name-based virtual server without SSL configured. Previously, a "ssl_ciphers aNULL;" was used for this. This workaround, however, is not compatible with TLSv1.3, in particular, when using BoringSSL, where it is not possible to configure TLSv1.3 ciphers at all. With this change, the ssl_reject_handshake directive is introduced, which instructs nginx to reject SSL handshakes with an "unrecognized_name" alert in a particular server block. For example, to reject handshake with names other than example.com, one can use the following configuration: server { listen 443 ssl; ssl_reject_handshake on; } server { listen 443 ssl; server_name example.com; ssl_certificate example.com.crt; ssl_certificate_key example.com.key; } The following configuration can be used to reject all SSL handshakes without SNI server name provided: server { listen 443 ssl; ssl_reject_handshake on; } server { listen 443 ssl; server_name ~^; ssl_certificate example.crt; ssl_certificate_key example.key; } Additionally, the ssl_reject_handshake directive makes configuring certificates for the default server block optional. If no certificates are configured in the default server for a given listening socket, certificates must be defined in all non-default server blocks with the listening socket in question.

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


#ifndef _NGX_MAIL_SMTP_MODULE_H_INCLUDED_
#define _NGX_MAIL_SMTP_MODULE_H_INCLUDED_


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


typedef struct {
    ngx_msec_t   greeting_delay;

    size_t       client_buffer_size;

    ngx_str_t    capability;
    ngx_str_t    starttls_capability;
    ngx_str_t    starttls_only_capability;

    ngx_str_t    server_name;
    ngx_str_t    greeting;

    ngx_uint_t   auth_methods;

    ngx_array_t  capabilities;
} ngx_mail_smtp_srv_conf_t;


void ngx_mail_smtp_init_session(ngx_mail_session_t *s, ngx_connection_t *c);
void ngx_mail_smtp_init_protocol(ngx_event_t *rev);
void ngx_mail_smtp_auth_state(ngx_event_t *rev);
ngx_int_t ngx_mail_smtp_parse_command(ngx_mail_session_t *s);


extern ngx_module_t  ngx_mail_smtp_module;


#endif /* _NGX_MAIL_SMTP_MODULE_H_INCLUDED_ */