view src/stream/ngx_stream_set_module.c @ 7732:59e1c73fe02b

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.
author Maxim Dounin <mdounin@mdounin.ru>
date Thu, 22 Oct 2020 18:02:28 +0300
parents 45e9281c6c5b
children
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/*
 * Copyright (C) Pavel Pautov
 * Copyright (C) Nginx, Inc.
 */


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


typedef struct {
    ngx_int_t                   index;
    ngx_stream_set_variable_pt  set_handler;
    uintptr_t                   data;
    ngx_stream_complex_value_t  value;
} ngx_stream_set_cmd_t;


typedef struct {
    ngx_array_t                 commands;
} ngx_stream_set_srv_conf_t;


static ngx_int_t ngx_stream_set_handler(ngx_stream_session_t *s);
static ngx_int_t ngx_stream_set_var(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_stream_set_init(ngx_conf_t *cf);
static void *ngx_stream_set_create_srv_conf(ngx_conf_t *cf);
static char *ngx_stream_set(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);


static ngx_command_t  ngx_stream_set_commands[] = {

    { ngx_string("set"),
      NGX_STREAM_SRV_CONF|NGX_CONF_TAKE2,
      ngx_stream_set,
      NGX_STREAM_SRV_CONF_OFFSET,
      0,
      NULL },

      ngx_null_command
};


static ngx_stream_module_t  ngx_stream_set_module_ctx = {
    NULL,                                  /* preconfiguration */
    ngx_stream_set_init,                   /* postconfiguration */

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

    ngx_stream_set_create_srv_conf,        /* create server configuration */
    NULL                                   /* merge server configuration */
};


ngx_module_t  ngx_stream_set_module = {
    NGX_MODULE_V1,
    &ngx_stream_set_module_ctx,            /* module context */
    ngx_stream_set_commands,               /* module directives */
    NGX_STREAM_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_int_t
ngx_stream_set_handler(ngx_stream_session_t *s)
{
    ngx_str_t                     str;
    ngx_uint_t                    i;
    ngx_stream_set_cmd_t         *cmds;
    ngx_stream_set_srv_conf_t    *scf;
    ngx_stream_variable_value_t   vv;

    scf = ngx_stream_get_module_srv_conf(s, ngx_stream_set_module);
    cmds = scf->commands.elts;
    vv = ngx_stream_variable_null_value;

    for (i = 0; i < scf->commands.nelts; i++) {
        if (ngx_stream_complex_value(s, &cmds[i].value, &str) != NGX_OK) {
            return NGX_ERROR;
        }

        if (cmds[i].set_handler != NULL) {
            vv.len = str.len;
            vv.data = str.data;
            cmds[i].set_handler(s, &vv, cmds[i].data);

        } else {
            s->variables[cmds[i].index].len = str.len;
            s->variables[cmds[i].index].valid = 1;
            s->variables[cmds[i].index].no_cacheable = 0;
            s->variables[cmds[i].index].not_found = 0;
            s->variables[cmds[i].index].data = str.data;
        }
    }

    return NGX_DECLINED;
}


static ngx_int_t
ngx_stream_set_var(ngx_stream_session_t *s, ngx_stream_variable_value_t *v,
    uintptr_t data)
{
    *v = ngx_stream_variable_null_value;

    return NGX_OK;
}


static ngx_int_t
ngx_stream_set_init(ngx_conf_t *cf)
{
    ngx_stream_handler_pt        *h;
    ngx_stream_core_main_conf_t  *cmcf;

    cmcf = ngx_stream_conf_get_module_main_conf(cf, ngx_stream_core_module);

    h = ngx_array_push(&cmcf->phases[NGX_STREAM_PREACCESS_PHASE].handlers);
    if (h == NULL) {
        return NGX_ERROR;
    }

    *h = ngx_stream_set_handler;

    return NGX_OK;
}


static void *
ngx_stream_set_create_srv_conf(ngx_conf_t *cf)
{
    ngx_stream_set_srv_conf_t  *conf;

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

    /*
     * set by ngx_pcalloc():
     *
     *     conf->commands = { NULL };
     */

    return conf;
}


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

    ngx_str_t                           *args;
    ngx_int_t                            index;
    ngx_stream_set_cmd_t                *set_cmd;
    ngx_stream_variable_t               *v;
    ngx_stream_compile_complex_value_t   ccv;

    args = cf->args->elts;

    if (args[1].data[0] != '$') {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "invalid variable name \"%V\"", &args[1]);
        return NGX_CONF_ERROR;
    }

    args[1].len--;
    args[1].data++;

    v = ngx_stream_add_variable(cf, &args[1],
                                NGX_STREAM_VAR_CHANGEABLE|NGX_STREAM_VAR_WEAK);
    if (v == NULL) {
        return NGX_CONF_ERROR;
    }

    index = ngx_stream_get_variable_index(cf, &args[1]);
    if (index == NGX_ERROR) {
        return NGX_CONF_ERROR;
    }

    if (v->get_handler == NULL) {
        v->get_handler = ngx_stream_set_var;
    }

    if (scf->commands.elts == NULL) {
        if (ngx_array_init(&scf->commands, cf->pool, 1,
                           sizeof(ngx_stream_set_cmd_t))
            != NGX_OK)
        {
            return NGX_CONF_ERROR;
        }
    }

    set_cmd = ngx_array_push(&scf->commands);
    if (set_cmd == NULL) {
        return NGX_CONF_ERROR;
    }

    set_cmd->index = index;
    set_cmd->set_handler = v->set_handler;
    set_cmd->data = v->data;

    ngx_memzero(&ccv, sizeof(ngx_stream_compile_complex_value_t));

    ccv.cf = cf;
    ccv.value = &args[2];
    ccv.complex_value = &set_cmd->value;

    if (ngx_stream_compile_complex_value(&ccv) != NGX_OK) {
        return NGX_CONF_ERROR;
    }

    return NGX_CONF_OK;
}