Merging r4034, r4186, r4187, r4229, r4235, r4237: SSL related fixes: *) Better handling of various per-server ssl options with SNI. SSL_set_SSL_CTX() doesn't touch values cached within ssl connection structure, it only changes certificates (at least as of now, OpenSSL 1.0.0d and earlier). As a result settings like ssl_verify_client, ssl_verify_depth, ssl_prefer_server_ciphers are only configurable on per-socket basis while with SNI it should be possible to specify them different for two servers listening on the same socket. Workaround is to explicitly re-apply settings we care about from context to ssl connection in servername callback. Note that SSL_clear_options() is only available in OpenSSL 0.9.8m+. I.e. with older versions it is not possible to clear ssl_prefer_server_ciphers option if it's set in default server for a socket. *) Disabling SSL compression. This saves about 300K per SSL connection. The SSL_OP_NO_COMPRESSION option is available since OpenSSL 1.0.0. *) Releasing memory of idle SSL connection. This saves about 34K per SSL connection. The SSL_MODE_RELEASE_BUFFERS option is available since OpenSSL 1.0.0d. *) Decrease of log level of some SSL handshake errors. *) Fixed segfault on configuration testing with ssl (ticket #37). The following config caused segmentation fault due to conf->file not being properly set if "ssl on" was inherited from the http level: http { ssl on; server { } } *) Silently ignoring a stale global SSL error left after disabled renegotiation.

/*
 * Copyright (C) Igor Sysoev
 */


#ifndef _NGX_MAIL_SSL_H_INCLUDED_
#define _NGX_MAIL_SSL_H_INCLUDED_


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


#define NGX_MAIL_STARTTLS_OFF   0
#define NGX_MAIL_STARTTLS_ON    1
#define NGX_MAIL_STARTTLS_ONLY  2


typedef struct {
    ngx_flag_t       enable;
    ngx_flag_t       prefer_server_ciphers;

    ngx_ssl_t        ssl;

    ngx_uint_t       starttls;
    ngx_uint_t       protocols;

    ssize_t          builtin_session_cache;

    time_t           session_timeout;

    ngx_str_t        certificate;
    ngx_str_t        certificate_key;
    ngx_str_t        dhparam;
    ngx_str_t        ecdh_curve;

    ngx_str_t        ciphers;

    ngx_shm_zone_t  *shm_zone;

    u_char          *file;
    ngx_uint_t       line;
} ngx_mail_ssl_conf_t;


extern ngx_module_t  ngx_mail_ssl_module;


#endif /* _NGX_MAIL_SSL_H_INCLUDED_ */