view src/mail/ngx_mail_ssl_module.c @ 5398:04e43d03e153

Mail: smtp pipelining support. Basically, this does the following two changes (and corresponding modifications of related code): 1. Does not reset session buffer unless it's reached it's end, and always wait for LF to terminate command (even if we detected invalid command). 2. Record command name to make it available for handlers (since now we can't assume that command starts from s->buffer->start).
author Maxim Dounin <mdounin@mdounin.ru>
date Mon, 30 Sep 2013 22:09:57 +0400
parents 0fbcfab0bfd7
children 09fc4598fc8e
line wrap: on
line source


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


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


#define NGX_DEFAULT_CIPHERS     "HIGH:!aNULL:!MD5"
#define NGX_DEFAULT_ECDH_CURVE  "prime256v1"


static void *ngx_mail_ssl_create_conf(ngx_conf_t *cf);
static char *ngx_mail_ssl_merge_conf(ngx_conf_t *cf, void *parent, void *child);

static char *ngx_mail_ssl_enable(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static char *ngx_mail_ssl_starttls(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static char *ngx_mail_ssl_session_cache(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);


static ngx_conf_enum_t  ngx_mail_starttls_state[] = {
    { ngx_string("off"), NGX_MAIL_STARTTLS_OFF },
    { ngx_string("on"), NGX_MAIL_STARTTLS_ON },
    { ngx_string("only"), NGX_MAIL_STARTTLS_ONLY },
    { ngx_null_string, 0 }
};



static ngx_conf_bitmask_t  ngx_mail_ssl_protocols[] = {
    { ngx_string("SSLv2"), NGX_SSL_SSLv2 },
    { ngx_string("SSLv3"), NGX_SSL_SSLv3 },
    { ngx_string("TLSv1"), NGX_SSL_TLSv1 },
    { ngx_string("TLSv1.1"), NGX_SSL_TLSv1_1 },
    { ngx_string("TLSv1.2"), NGX_SSL_TLSv1_2 },
    { ngx_null_string, 0 }
};


static ngx_command_t  ngx_mail_ssl_commands[] = {

    { ngx_string("ssl"),
      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_FLAG,
      ngx_mail_ssl_enable,
      NGX_MAIL_SRV_CONF_OFFSET,
      offsetof(ngx_mail_ssl_conf_t, enable),
      NULL },

    { ngx_string("starttls"),
      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1,
      ngx_mail_ssl_starttls,
      NGX_MAIL_SRV_CONF_OFFSET,
      offsetof(ngx_mail_ssl_conf_t, starttls),
      ngx_mail_starttls_state },

    { ngx_string("ssl_certificate"),
      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_str_slot,
      NGX_MAIL_SRV_CONF_OFFSET,
      offsetof(ngx_mail_ssl_conf_t, certificate),
      NULL },

    { ngx_string("ssl_certificate_key"),
      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_str_slot,
      NGX_MAIL_SRV_CONF_OFFSET,
      offsetof(ngx_mail_ssl_conf_t, certificate_key),
      NULL },

    { ngx_string("ssl_dhparam"),
      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_str_slot,
      NGX_MAIL_SRV_CONF_OFFSET,
      offsetof(ngx_mail_ssl_conf_t, dhparam),
      NULL },

    { ngx_string("ssl_ecdh_curve"),
      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_str_slot,
      NGX_MAIL_SRV_CONF_OFFSET,
      offsetof(ngx_mail_ssl_conf_t, ecdh_curve),
      NULL },

    { ngx_string("ssl_protocols"),
      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_1MORE,
      ngx_conf_set_bitmask_slot,
      NGX_MAIL_SRV_CONF_OFFSET,
      offsetof(ngx_mail_ssl_conf_t, protocols),
      &ngx_mail_ssl_protocols },

    { ngx_string("ssl_ciphers"),
      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_str_slot,
      NGX_MAIL_SRV_CONF_OFFSET,
      offsetof(ngx_mail_ssl_conf_t, ciphers),
      NULL },

    { ngx_string("ssl_prefer_server_ciphers"),
      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_FLAG,
      ngx_conf_set_flag_slot,
      NGX_MAIL_SRV_CONF_OFFSET,
      offsetof(ngx_mail_ssl_conf_t, prefer_server_ciphers),
      NULL },

    { ngx_string("ssl_session_cache"),
      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE12,
      ngx_mail_ssl_session_cache,
      NGX_MAIL_SRV_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("ssl_session_timeout"),
      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_sec_slot,
      NGX_MAIL_SRV_CONF_OFFSET,
      offsetof(ngx_mail_ssl_conf_t, session_timeout),
      NULL },

      ngx_null_command
};


static ngx_mail_module_t  ngx_mail_ssl_module_ctx = {
    NULL,                                  /* protocol */

    NULL,                                  /* create main configuration */
    NULL,                                  /* init main configuration */

    ngx_mail_ssl_create_conf,              /* create server configuration */
    ngx_mail_ssl_merge_conf                /* merge server configuration */
};


ngx_module_t  ngx_mail_ssl_module = {
    NGX_MODULE_V1,
    &ngx_mail_ssl_module_ctx,              /* module context */
    ngx_mail_ssl_commands,                 /* module directives */
    NGX_MAIL_MODULE,                       /* module type */
    NULL,                                  /* init master */
    NULL,                                  /* init module */
    NULL,                                  /* init process */
    NULL,                                  /* init thread */
    NULL,                                  /* exit thread */
    NULL,                                  /* exit process */
    NULL,                                  /* exit master */
    NGX_MODULE_V1_PADDING
};


static ngx_str_t ngx_mail_ssl_sess_id_ctx = ngx_string("MAIL");


static void *
ngx_mail_ssl_create_conf(ngx_conf_t *cf)
{
    ngx_mail_ssl_conf_t  *scf;

    scf = ngx_pcalloc(cf->pool, sizeof(ngx_mail_ssl_conf_t));
    if (scf == NULL) {
        return NULL;
    }

    /*
     * set by ngx_pcalloc():
     *
     *     scf->protocols = 0;
     *     scf->certificate = { 0, NULL };
     *     scf->certificate_key = { 0, NULL };
     *     scf->dhparam = { 0, NULL };
     *     scf->ecdh_curve = { 0, NULL };
     *     scf->ciphers = { 0, NULL };
     *     scf->shm_zone = NULL;
     */

    scf->enable = NGX_CONF_UNSET;
    scf->starttls = NGX_CONF_UNSET_UINT;
    scf->prefer_server_ciphers = NGX_CONF_UNSET;
    scf->builtin_session_cache = NGX_CONF_UNSET;
    scf->session_timeout = NGX_CONF_UNSET;

    return scf;
}


static char *
ngx_mail_ssl_merge_conf(ngx_conf_t *cf, void *parent, void *child)
{
    ngx_mail_ssl_conf_t *prev = parent;
    ngx_mail_ssl_conf_t *conf = child;

    char                *mode;
    ngx_pool_cleanup_t  *cln;

    ngx_conf_merge_value(conf->enable, prev->enable, 0);
    ngx_conf_merge_uint_value(conf->starttls, prev->starttls,
                         NGX_MAIL_STARTTLS_OFF);

    ngx_conf_merge_value(conf->session_timeout,
                         prev->session_timeout, 300);

    ngx_conf_merge_value(conf->prefer_server_ciphers,
                         prev->prefer_server_ciphers, 0);

    ngx_conf_merge_bitmask_value(conf->protocols, prev->protocols,
                         (NGX_CONF_BITMASK_SET|NGX_SSL_SSLv3|NGX_SSL_TLSv1
                          |NGX_SSL_TLSv1_1|NGX_SSL_TLSv1_2));

    ngx_conf_merge_str_value(conf->certificate, prev->certificate, "");
    ngx_conf_merge_str_value(conf->certificate_key, prev->certificate_key, "");

    ngx_conf_merge_str_value(conf->dhparam, prev->dhparam, "");

    ngx_conf_merge_str_value(conf->ecdh_curve, prev->ecdh_curve,
                         NGX_DEFAULT_ECDH_CURVE);

    ngx_conf_merge_str_value(conf->ciphers, prev->ciphers, NGX_DEFAULT_CIPHERS);


    conf->ssl.log = cf->log;

    if (conf->enable) {
       mode = "ssl";

    } else if (conf->starttls != NGX_MAIL_STARTTLS_OFF) {
       mode = "starttls";

    } else {
       mode = "";
    }

    if (*mode) {

        if (conf->certificate.len == 0) {
            ngx_log_error(NGX_LOG_EMERG, cf->log, 0,
                          "no \"ssl_certificate\" is defined for "
                          "the \"%s\" directive in %s:%ui",
                          mode, conf->file, conf->line);
            return NGX_CONF_ERROR;
        }

        if (conf->certificate_key.len == 0) {
            ngx_log_error(NGX_LOG_EMERG, cf->log, 0,
                          "no \"ssl_certificate_key\" is defined for "
                          "the \"%s\" directive in %s:%ui",
                          mode, conf->file, conf->line);
            return NGX_CONF_ERROR;
        }

    } else {

        if (conf->certificate.len == 0) {
            return NGX_CONF_OK;
        }

        if (conf->certificate_key.len == 0) {
            ngx_log_error(NGX_LOG_EMERG, cf->log, 0,
                          "no \"ssl_certificate_key\" is defined "
                          "for certificate \"%V\"",
                          &conf->certificate);
            return NGX_CONF_ERROR;
        }
    }

    if (ngx_ssl_create(&conf->ssl, conf->protocols, NULL) != NGX_OK) {
        return NGX_CONF_ERROR;
    }

    cln = ngx_pool_cleanup_add(cf->pool, 0);
    if (cln == NULL) {
        return NGX_CONF_ERROR;
    }

    cln->handler = ngx_ssl_cleanup_ctx;
    cln->data = &conf->ssl;

    if (ngx_ssl_certificate(cf, &conf->ssl, &conf->certificate,
                            &conf->certificate_key)
        != NGX_OK)
    {
        return NGX_CONF_ERROR;
    }

    if (SSL_CTX_set_cipher_list(conf->ssl.ctx,
                                (const char *) conf->ciphers.data)
        == 0)
    {
        ngx_ssl_error(NGX_LOG_EMERG, cf->log, 0,
                      "SSL_CTX_set_cipher_list(\"%V\") failed",
                      &conf->ciphers);
        return NGX_CONF_ERROR;
    }

    if (conf->prefer_server_ciphers) {
        SSL_CTX_set_options(conf->ssl.ctx, SSL_OP_CIPHER_SERVER_PREFERENCE);
    }

    SSL_CTX_set_tmp_rsa_callback(conf->ssl.ctx, ngx_ssl_rsa512_key_callback);

    if (ngx_ssl_dhparam(cf, &conf->ssl, &conf->dhparam) != NGX_OK) {
        return NGX_CONF_ERROR;
    }

    if (ngx_ssl_ecdh_curve(cf, &conf->ssl, &conf->ecdh_curve) != NGX_OK) {
        return NGX_CONF_ERROR;
    }

    ngx_conf_merge_value(conf->builtin_session_cache,
                         prev->builtin_session_cache, NGX_SSL_NONE_SCACHE);

    if (conf->shm_zone == NULL) {
        conf->shm_zone = prev->shm_zone;
    }

    if (ngx_ssl_session_cache(&conf->ssl, &ngx_mail_ssl_sess_id_ctx,
                              conf->builtin_session_cache,
                              conf->shm_zone, conf->session_timeout)
        != NGX_OK)
    {
        return NGX_CONF_ERROR;
    }

    return NGX_CONF_OK;
}


static char *
ngx_mail_ssl_enable(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_mail_ssl_conf_t  *scf = conf;

    char  *rv;

    rv = ngx_conf_set_flag_slot(cf, cmd, conf);

    if (rv != NGX_CONF_OK) {
        return rv;
    }

    if (scf->enable && (ngx_int_t) scf->starttls > NGX_MAIL_STARTTLS_OFF) {
        ngx_conf_log_error(NGX_LOG_WARN, cf, 0,
                           "\"starttls\" directive conflicts with \"ssl on\"");
        return NGX_CONF_ERROR;
    }

    scf->file = cf->conf_file->file.name.data;
    scf->line = cf->conf_file->line;

    return NGX_CONF_OK;
}


static char *
ngx_mail_ssl_starttls(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_mail_ssl_conf_t  *scf = conf;

    char  *rv;

    rv = ngx_conf_set_enum_slot(cf, cmd, conf);

    if (rv != NGX_CONF_OK) {
        return rv;
    }

    if (scf->enable == 1 && (ngx_int_t) scf->starttls > NGX_MAIL_STARTTLS_OFF) {
        ngx_conf_log_error(NGX_LOG_WARN, cf, 0,
                           "\"ssl\" directive conflicts with \"starttls\"");
        return NGX_CONF_ERROR;
    }

    scf->file = cf->conf_file->file.name.data;
    scf->line = cf->conf_file->line;

    return NGX_CONF_OK;
}


static char *
ngx_mail_ssl_session_cache(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_mail_ssl_conf_t  *scf = conf;

    size_t       len;
    ngx_str_t   *value, name, size;
    ngx_int_t    n;
    ngx_uint_t   i, j;

    value = cf->args->elts;

    for (i = 1; i < cf->args->nelts; i++) {

        if (ngx_strcmp(value[i].data, "off") == 0) {
            scf->builtin_session_cache = NGX_SSL_NO_SCACHE;
            continue;
        }

        if (ngx_strcmp(value[i].data, "none") == 0) {
            scf->builtin_session_cache = NGX_SSL_NONE_SCACHE;
            continue;
        }

        if (ngx_strcmp(value[i].data, "builtin") == 0) {
            scf->builtin_session_cache = NGX_SSL_DFLT_BUILTIN_SCACHE;
            continue;
        }

        if (value[i].len > sizeof("builtin:") - 1
            && ngx_strncmp(value[i].data, "builtin:", sizeof("builtin:") - 1)
               == 0)
        {
            n = ngx_atoi(value[i].data + sizeof("builtin:") - 1,
                         value[i].len - (sizeof("builtin:") - 1));

            if (n == NGX_ERROR) {
                goto invalid;
            }

            scf->builtin_session_cache = n;

            continue;
        }

        if (value[i].len > sizeof("shared:") - 1
            && ngx_strncmp(value[i].data, "shared:", sizeof("shared:") - 1)
               == 0)
        {
            len = 0;

            for (j = sizeof("shared:") - 1; j < value[i].len; j++) {
                if (value[i].data[j] == ':') {
                    break;
                }

                len++;
            }

            if (len == 0) {
                goto invalid;
            }

            name.len = len;
            name.data = value[i].data + sizeof("shared:") - 1;

            size.len = value[i].len - j - 1;
            size.data = name.data + len + 1;

            n = ngx_parse_size(&size);

            if (n == NGX_ERROR) {
                goto invalid;
            }

            if (n < (ngx_int_t) (8 * ngx_pagesize)) {
                ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                   "session cache \"%V\" is too small",
                                   &value[i]);

                return NGX_CONF_ERROR;
            }

            scf->shm_zone = ngx_shared_memory_add(cf, &name, n,
                                                   &ngx_mail_ssl_module);
            if (scf->shm_zone == NULL) {
                return NGX_CONF_ERROR;
            }

            scf->shm_zone->init = ngx_ssl_session_cache_init;

            continue;
        }

        goto invalid;
    }

    if (scf->shm_zone && scf->builtin_session_cache == NGX_CONF_UNSET) {
        scf->builtin_session_cache = NGX_SSL_NO_BUILTIN_SCACHE;
    }

    return NGX_CONF_OK;

invalid:

    ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                       "invalid session cache \"%V\"", &value[i]);

    return NGX_CONF_ERROR;
}