view src/http/modules/ngx_http_degradation_module.c @ 7361:c09c7d47acb9

SSL: logging level of "no suitable signature algorithm". The "no suitable signature algorithm" errors are reported by OpenSSL 1.1.1 when using TLSv1.3 if there are no shared signature algorithms. In particular, this can happen if the client limits available signature algorithms to something we don't have a certificate for, or to an empty list. For example, the following command: openssl s_client -connect 127.0.0.1:8443 -sigalgs rsa_pkcs1_sha1 will always result in the "no suitable signature algorithm" error as the "rsa_pkcs1_sha1" algorithm refers solely to signatures which appear in certificates and not defined for use in TLS 1.3 handshake messages. The SSL_R_NO_COMMON_SIGNATURE_ALGORITHMS error is what BoringSSL returns in the same situation.
author Maxim Dounin <mdounin@mdounin.ru>
date Tue, 25 Sep 2018 14:00:04 +0300
parents 67653855682e
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


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


typedef struct {
    size_t      sbrk_size;
} ngx_http_degradation_main_conf_t;


typedef struct {
    ngx_uint_t  degrade;
} ngx_http_degradation_loc_conf_t;


static ngx_conf_enum_t  ngx_http_degrade[] = {
    { ngx_string("204"), 204 },
    { ngx_string("444"), 444 },
    { ngx_null_string, 0 }
};


static void *ngx_http_degradation_create_main_conf(ngx_conf_t *cf);
static void *ngx_http_degradation_create_loc_conf(ngx_conf_t *cf);
static char *ngx_http_degradation_merge_loc_conf(ngx_conf_t *cf, void *parent,
    void *child);
static char *ngx_http_degradation(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static ngx_int_t ngx_http_degradation_init(ngx_conf_t *cf);


static ngx_command_t  ngx_http_degradation_commands[] = {

    { ngx_string("degradation"),
      NGX_HTTP_MAIN_CONF|NGX_CONF_TAKE1,
      ngx_http_degradation,
      NGX_HTTP_MAIN_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("degrade"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_enum_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_degradation_loc_conf_t, degrade),
      &ngx_http_degrade },

      ngx_null_command
};


static ngx_http_module_t  ngx_http_degradation_module_ctx = {
    NULL,                                  /* preconfiguration */
    ngx_http_degradation_init,             /* postconfiguration */

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

    NULL,                                  /* create server configuration */
    NULL,                                  /* merge server configuration */

    ngx_http_degradation_create_loc_conf,  /* create location configuration */
    ngx_http_degradation_merge_loc_conf    /* merge location configuration */
};


ngx_module_t  ngx_http_degradation_module = {
    NGX_MODULE_V1,
    &ngx_http_degradation_module_ctx,      /* module context */
    ngx_http_degradation_commands,         /* module directives */
    NGX_HTTP_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_http_degradation_handler(ngx_http_request_t *r)
{
    ngx_http_degradation_loc_conf_t  *dlcf;

    dlcf = ngx_http_get_module_loc_conf(r, ngx_http_degradation_module);

    if (dlcf->degrade && ngx_http_degraded(r)) {
        return dlcf->degrade;
    }

    return NGX_DECLINED;
}


ngx_uint_t
ngx_http_degraded(ngx_http_request_t *r)
{
    time_t                             now;
    ngx_uint_t                         log;
    static size_t                      sbrk_size;
    static time_t                      sbrk_time;
    ngx_http_degradation_main_conf_t  *dmcf;

    dmcf = ngx_http_get_module_main_conf(r, ngx_http_degradation_module);

    if (dmcf->sbrk_size) {

        log = 0;
        now = ngx_time();

        /* lock mutex */

        if (now != sbrk_time) {

            /*
             * ELF/i386 is loaded at 0x08000000, 128M
             * ELF/amd64 is loaded at 0x00400000, 4M
             *
             * use a function address to subtract the loading address
             */

            sbrk_size = (size_t) sbrk(0) - ((uintptr_t) ngx_palloc & ~0x3FFFFF);
            sbrk_time = now;
            log = 1;
        }

        /* unlock mutex */

        if (sbrk_size >= dmcf->sbrk_size) {
            if (log) {
                ngx_log_error(NGX_LOG_NOTICE, r->connection->log, 0,
                              "degradation sbrk:%uzM",
                              sbrk_size / (1024 * 1024));
            }

            return 1;
        }
    }

    return 0;
}


static void *
ngx_http_degradation_create_main_conf(ngx_conf_t *cf)
{
    ngx_http_degradation_main_conf_t  *dmcf;

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

    return dmcf;
}


static void *
ngx_http_degradation_create_loc_conf(ngx_conf_t *cf)
{
    ngx_http_degradation_loc_conf_t  *conf;

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

    conf->degrade = NGX_CONF_UNSET_UINT;

    return conf;
}


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

    ngx_conf_merge_uint_value(conf->degrade, prev->degrade, 0);

    return NGX_CONF_OK;
}


static char *
ngx_http_degradation(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_http_degradation_main_conf_t  *dmcf = conf;

    ngx_str_t  *value, s;

    value = cf->args->elts;

    if (ngx_strncmp(value[1].data, "sbrk=", 5) == 0) {

        s.len = value[1].len - 5;
        s.data = value[1].data + 5;

        dmcf->sbrk_size = ngx_parse_size(&s);
        if (dmcf->sbrk_size == (size_t) NGX_ERROR) {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "invalid sbrk size \"%V\"", &value[1]);
            return NGX_CONF_ERROR;
        }

        return NGX_CONF_OK;
    }

    ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                       "invalid parameter \"%V\"", &value[1]);

    return NGX_CONF_ERROR;
}


static ngx_int_t
ngx_http_degradation_init(ngx_conf_t *cf)
{
    ngx_http_handler_pt        *h;
    ngx_http_core_main_conf_t  *cmcf;

    cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module);

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

    *h = ngx_http_degradation_handler;

    return NGX_OK;
}