view src/stream/ngx_stream_return_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 56fc55e32f23
children
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/*
 * Copyright (C) Roman Arutyunyan
 * Copyright (C) Nginx, Inc.
 */


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


typedef struct {
    ngx_stream_complex_value_t   text;
} ngx_stream_return_srv_conf_t;


typedef struct {
    ngx_chain_t                 *out;
} ngx_stream_return_ctx_t;


static void ngx_stream_return_handler(ngx_stream_session_t *s);
static void ngx_stream_return_write_handler(ngx_event_t *ev);

static void *ngx_stream_return_create_srv_conf(ngx_conf_t *cf);
static char *ngx_stream_return(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);


static ngx_command_t  ngx_stream_return_commands[] = {

    { ngx_string("return"),
      NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_stream_return,
      NGX_STREAM_SRV_CONF_OFFSET,
      0,
      NULL },

      ngx_null_command
};


static ngx_stream_module_t  ngx_stream_return_module_ctx = {
    NULL,                                  /* preconfiguration */
    NULL,                                  /* postconfiguration */

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

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


ngx_module_t  ngx_stream_return_module = {
    NGX_MODULE_V1,
    &ngx_stream_return_module_ctx,         /* module context */
    ngx_stream_return_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 void
ngx_stream_return_handler(ngx_stream_session_t *s)
{
    ngx_str_t                      text;
    ngx_buf_t                     *b;
    ngx_connection_t              *c;
    ngx_stream_return_ctx_t       *ctx;
    ngx_stream_return_srv_conf_t  *rscf;

    c = s->connection;

    c->log->action = "returning text";

    rscf = ngx_stream_get_module_srv_conf(s, ngx_stream_return_module);

    if (ngx_stream_complex_value(s, &rscf->text, &text) != NGX_OK) {
        ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
        return;
    }

    ngx_log_debug1(NGX_LOG_DEBUG_STREAM, c->log, 0,
                   "stream return text: \"%V\"", &text);

    if (text.len == 0) {
        ngx_stream_finalize_session(s, NGX_STREAM_OK);
        return;
    }

    ctx = ngx_pcalloc(c->pool, sizeof(ngx_stream_return_ctx_t));
    if (ctx == NULL) {
        ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
        return;
    }

    ngx_stream_set_ctx(s, ctx, ngx_stream_return_module);

    b = ngx_calloc_buf(c->pool);
    if (b == NULL) {
        ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
        return;
    }

    b->memory = 1;
    b->pos = text.data;
    b->last = text.data + text.len;
    b->last_buf = 1;

    ctx->out = ngx_alloc_chain_link(c->pool);
    if (ctx->out == NULL) {
        ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
        return;
    }

    ctx->out->buf = b;
    ctx->out->next = NULL;

    c->write->handler = ngx_stream_return_write_handler;

    ngx_stream_return_write_handler(c->write);
}


static void
ngx_stream_return_write_handler(ngx_event_t *ev)
{
    ngx_connection_t         *c;
    ngx_stream_session_t     *s;
    ngx_stream_return_ctx_t  *ctx;

    c = ev->data;
    s = c->data;

    if (ev->timedout) {
        ngx_connection_error(c, NGX_ETIMEDOUT, "connection timed out");
        ngx_stream_finalize_session(s, NGX_STREAM_OK);
        return;
    }

    ctx = ngx_stream_get_module_ctx(s, ngx_stream_return_module);

    if (ngx_stream_top_filter(s, ctx->out, 1) == NGX_ERROR) {
        ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
        return;
    }

    ctx->out = NULL;

    if (!c->buffered) {
        ngx_log_debug0(NGX_LOG_DEBUG_STREAM, c->log, 0,
                       "stream return done sending");
        ngx_stream_finalize_session(s, NGX_STREAM_OK);
        return;
    }

    if (ngx_handle_write_event(ev, 0) != NGX_OK) {
        ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
        return;
    }

    ngx_add_timer(ev, 5000);
}


static void *
ngx_stream_return_create_srv_conf(ngx_conf_t *cf)
{
    ngx_stream_return_srv_conf_t  *conf;

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

    return conf;
}


static char *
ngx_stream_return(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_stream_return_srv_conf_t *rscf = conf;

    ngx_str_t                           *value;
    ngx_stream_core_srv_conf_t          *cscf;
    ngx_stream_compile_complex_value_t   ccv;

    if (rscf->text.value.data) {
        return "is duplicate";
    }

    value = cf->args->elts;

    ngx_memzero(&ccv, sizeof(ngx_stream_compile_complex_value_t));

    ccv.cf = cf;
    ccv.value = &value[1];
    ccv.complex_value = &rscf->text;

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

    cscf = ngx_stream_conf_get_module_srv_conf(cf, ngx_stream_core_module);

    cscf->handler = ngx_stream_return_handler;

    return NGX_CONF_OK;
}