Mercurial > hg > nginx
view src/mail/ngx_mail_smtp_module.c @ 7360:8f25a44d9add
SSL: logging level of "no suitable key share".
The "no suitable key share" errors are reported by OpenSSL 1.1.1 when
using TLSv1.3 if there are no shared groups (that is, elliptic curves).
In particular, it is easy enough to trigger by using only a single
curve in ssl_ecdh_curve:
ssl_ecdh_curve secp384r1;
and using a different curve in the client:
openssl s_client -connect 127.0.0.1:443 -curves prime256v1
On the client side it is seen as "sslv3 alert handshake failure",
"SSL alert number 40":
0:error:14094410:SSL routines:ssl3_read_bytes:sslv3 alert handshake failure:ssl/record/rec_layer_s3.c:1528:SSL alert number 40
It can be also triggered with default ssl_ecdh_curve by using a curve
which is not in the default list (X25519, prime256v1, X448, secp521r1,
secp384r1):
openssl s_client -connect 127.0.0.1:8443 -curves brainpoolP512r1
Given that many clients hardcode prime256v1, these errors might become
a common problem with TLSv1.3 if ssl_ecdh_curve is redefined. Previously
this resulted in not using ECDH with such clients, but with TLSv1.3 it
is no longer possible and will result in a handshake failure.
The SSL_R_NO_SHARED_GROUP error is what BoringSSL returns in the same
situation.
Seen at:
https://serverfault.com/questions/932102/nginx-ssl-handshake-error-no-suitable-key-share
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Tue, 25 Sep 2018 13:59:53 +0300 |
parents | f18c285c2e59 |
children | dc955d274130 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #include <ngx_mail.h> #include <ngx_mail_smtp_module.h> static void *ngx_mail_smtp_create_srv_conf(ngx_conf_t *cf); static char *ngx_mail_smtp_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_conf_bitmask_t ngx_mail_smtp_auth_methods[] = { { ngx_string("plain"), NGX_MAIL_AUTH_PLAIN_ENABLED }, { ngx_string("login"), NGX_MAIL_AUTH_LOGIN_ENABLED }, { ngx_string("cram-md5"), NGX_MAIL_AUTH_CRAM_MD5_ENABLED }, { ngx_string("external"), NGX_MAIL_AUTH_EXTERNAL_ENABLED }, { ngx_string("none"), NGX_MAIL_AUTH_NONE_ENABLED }, { ngx_null_string, 0 } }; static ngx_str_t ngx_mail_smtp_auth_methods_names[] = { ngx_string("PLAIN"), ngx_string("LOGIN"), ngx_null_string, /* APOP */ ngx_string("CRAM-MD5"), ngx_string("EXTERNAL"), ngx_null_string /* NONE */ }; static ngx_mail_protocol_t ngx_mail_smtp_protocol = { ngx_string("smtp"), { 25, 465, 587, 0 }, NGX_MAIL_SMTP_PROTOCOL, ngx_mail_smtp_init_session, ngx_mail_smtp_init_protocol, ngx_mail_smtp_parse_command, ngx_mail_smtp_auth_state, ngx_string("451 4.3.2 Internal server error" CRLF), ngx_string("421 4.7.1 SSL certificate error" CRLF), ngx_string("421 4.7.1 No required SSL certificate" CRLF) }; static ngx_command_t ngx_mail_smtp_commands[] = { { ngx_string("smtp_client_buffer"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_conf_set_size_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_smtp_srv_conf_t, client_buffer_size), NULL }, { ngx_string("smtp_greeting_delay"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_conf_set_msec_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_smtp_srv_conf_t, greeting_delay), NULL }, { ngx_string("smtp_capabilities"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_1MORE, ngx_mail_capabilities, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_smtp_srv_conf_t, capabilities), NULL }, { ngx_string("smtp_auth"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_1MORE, ngx_conf_set_bitmask_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_smtp_srv_conf_t, auth_methods), &ngx_mail_smtp_auth_methods }, ngx_null_command }; static ngx_mail_module_t ngx_mail_smtp_module_ctx = { &ngx_mail_smtp_protocol, /* protocol */ NULL, /* create main configuration */ NULL, /* init main configuration */ ngx_mail_smtp_create_srv_conf, /* create server configuration */ ngx_mail_smtp_merge_srv_conf /* merge server configuration */ }; ngx_module_t ngx_mail_smtp_module = { NGX_MODULE_V1, &ngx_mail_smtp_module_ctx, /* module context */ ngx_mail_smtp_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 void * ngx_mail_smtp_create_srv_conf(ngx_conf_t *cf) { ngx_mail_smtp_srv_conf_t *sscf; sscf = ngx_pcalloc(cf->pool, sizeof(ngx_mail_smtp_srv_conf_t)); if (sscf == NULL) { return NULL; } sscf->client_buffer_size = NGX_CONF_UNSET_SIZE; sscf->greeting_delay = NGX_CONF_UNSET_MSEC; if (ngx_array_init(&sscf->capabilities, cf->pool, 4, sizeof(ngx_str_t)) != NGX_OK) { return NULL; } return sscf; } static char * ngx_mail_smtp_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_mail_smtp_srv_conf_t *prev = parent; ngx_mail_smtp_srv_conf_t *conf = child; u_char *p, *auth, *last; size_t size; ngx_str_t *c; ngx_uint_t i, m, auth_enabled; ngx_mail_core_srv_conf_t *cscf; ngx_conf_merge_size_value(conf->client_buffer_size, prev->client_buffer_size, (size_t) ngx_pagesize); ngx_conf_merge_msec_value(conf->greeting_delay, prev->greeting_delay, 0); ngx_conf_merge_bitmask_value(conf->auth_methods, prev->auth_methods, (NGX_CONF_BITMASK_SET |NGX_MAIL_AUTH_PLAIN_ENABLED |NGX_MAIL_AUTH_LOGIN_ENABLED)); cscf = ngx_mail_conf_get_module_srv_conf(cf, ngx_mail_core_module); size = sizeof("220 ESMTP ready" CRLF) - 1 + cscf->server_name.len; p = ngx_pnalloc(cf->pool, size); if (p == NULL) { return NGX_CONF_ERROR; } conf->greeting.len = size; conf->greeting.data = p; *p++ = '2'; *p++ = '2'; *p++ = '0'; *p++ = ' '; p = ngx_cpymem(p, cscf->server_name.data, cscf->server_name.len); ngx_memcpy(p, " ESMTP ready" CRLF, sizeof(" ESMTP ready" CRLF) - 1); size = sizeof("250 " CRLF) - 1 + cscf->server_name.len; p = ngx_pnalloc(cf->pool, size); if (p == NULL) { return NGX_CONF_ERROR; } conf->server_name.len = size; conf->server_name.data = p; *p++ = '2'; *p++ = '5'; *p++ = '0'; *p++ = ' '; p = ngx_cpymem(p, cscf->server_name.data, cscf->server_name.len); *p++ = CR; *p = LF; if (conf->capabilities.nelts == 0) { conf->capabilities = prev->capabilities; } size = sizeof("250-") - 1 + cscf->server_name.len + sizeof(CRLF) - 1; c = conf->capabilities.elts; for (i = 0; i < conf->capabilities.nelts; i++) { size += sizeof("250 ") - 1 + c[i].len + sizeof(CRLF) - 1; } auth_enabled = 0; for (m = NGX_MAIL_AUTH_PLAIN_ENABLED, i = 0; m <= NGX_MAIL_AUTH_EXTERNAL_ENABLED; m <<= 1, i++) { if (m & conf->auth_methods) { size += 1 + ngx_mail_smtp_auth_methods_names[i].len; auth_enabled = 1; } } if (auth_enabled) { size += sizeof("250 AUTH") - 1 + sizeof(CRLF) - 1; } p = ngx_pnalloc(cf->pool, size); if (p == NULL) { return NGX_CONF_ERROR; } conf->capability.len = size; conf->capability.data = p; last = p; *p++ = '2'; *p++ = '5'; *p++ = '0'; *p++ = '-'; p = ngx_cpymem(p, cscf->server_name.data, cscf->server_name.len); *p++ = CR; *p++ = LF; for (i = 0; i < conf->capabilities.nelts; i++) { last = p; *p++ = '2'; *p++ = '5'; *p++ = '0'; *p++ = '-'; p = ngx_cpymem(p, c[i].data, c[i].len); *p++ = CR; *p++ = LF; } auth = p; if (auth_enabled) { last = p; *p++ = '2'; *p++ = '5'; *p++ = '0'; *p++ = ' '; *p++ = 'A'; *p++ = 'U'; *p++ = 'T'; *p++ = 'H'; for (m = NGX_MAIL_AUTH_PLAIN_ENABLED, i = 0; m <= NGX_MAIL_AUTH_EXTERNAL_ENABLED; m <<= 1, i++) { if (m & conf->auth_methods) { *p++ = ' '; p = ngx_cpymem(p, ngx_mail_smtp_auth_methods_names[i].data, ngx_mail_smtp_auth_methods_names[i].len); } } *p++ = CR; *p = LF; } else { last[3] = ' '; } size += sizeof("250 STARTTLS" CRLF) - 1; p = ngx_pnalloc(cf->pool, size); if (p == NULL) { return NGX_CONF_ERROR; } conf->starttls_capability.len = size; conf->starttls_capability.data = p; p = ngx_cpymem(p, conf->capability.data, conf->capability.len); ngx_memcpy(p, "250 STARTTLS" CRLF, sizeof("250 STARTTLS" CRLF) - 1); p = conf->starttls_capability.data + (last - conf->capability.data) + 3; *p = '-'; size = (auth - conf->capability.data) + sizeof("250 STARTTLS" CRLF) - 1; p = ngx_pnalloc(cf->pool, size); if (p == NULL) { return NGX_CONF_ERROR; } conf->starttls_only_capability.len = size; conf->starttls_only_capability.data = p; p = ngx_cpymem(p, conf->capability.data, auth - conf->capability.data); ngx_memcpy(p, "250 STARTTLS" CRLF, sizeof("250 STARTTLS" CRLF) - 1); if (last < auth) { p = conf->starttls_only_capability.data + (last - conf->capability.data) + 3; *p = '-'; } return NGX_CONF_OK; }