Mercurial > hg > nginx
view src/mail/ngx_mail_ssl_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 | 3bff3f397c05 |
| children | 7ce28b4cc57e |
line wrap: on
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/* * 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 "auto" 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_password_file(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 char *ngx_mail_ssl_conf_command_check(ngx_conf_t *cf, void *post, void *data); 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_string("TLSv1.3"), NGX_SSL_TLSv1_3 }, { ngx_null_string, 0 } }; static ngx_conf_enum_t ngx_mail_ssl_verify[] = { { ngx_string("off"), 0 }, { ngx_string("on"), 1 }, { ngx_string("optional"), 2 }, { ngx_string("optional_no_ca"), 3 }, { ngx_null_string, 0 } }; static ngx_conf_deprecated_t ngx_mail_ssl_deprecated = { ngx_conf_deprecated, "ssl", "listen ... ssl" }; static ngx_conf_post_t ngx_mail_ssl_conf_command_post = { ngx_mail_ssl_conf_command_check }; 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), &ngx_mail_ssl_deprecated }, { 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_array_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, certificates), NULL }, { ngx_string("ssl_certificate_key"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_conf_set_str_array_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, certificate_keys), NULL }, { ngx_string("ssl_password_file"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_mail_ssl_password_file, NGX_MAIL_SRV_CONF_OFFSET, 0, 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_tickets"), 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, session_tickets), NULL }, { ngx_string("ssl_session_ticket_key"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_conf_set_str_array_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, session_ticket_keys), 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_string("ssl_verify_client"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_conf_set_enum_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, verify), &ngx_mail_ssl_verify }, { ngx_string("ssl_verify_depth"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_conf_set_num_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, verify_depth), NULL }, { ngx_string("ssl_client_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, client_certificate), NULL }, { ngx_string("ssl_trusted_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, trusted_certificate), NULL }, { ngx_string("ssl_crl"), 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, crl), NULL }, { ngx_string("ssl_conf_command"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE2, ngx_conf_set_keyval_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, conf_commands), &ngx_mail_ssl_conf_command_post }, 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->listen = 0; * scf->protocols = 0; * scf->dhparam = { 0, NULL }; * scf->ecdh_curve = { 0, NULL }; * scf->client_certificate = { 0, NULL }; * scf->trusted_certificate = { 0, NULL }; * scf->crl = { 0, NULL }; * scf->ciphers = { 0, NULL }; * scf->shm_zone = NULL; */ scf->enable = NGX_CONF_UNSET; scf->starttls = NGX_CONF_UNSET_UINT; scf->certificates = NGX_CONF_UNSET_PTR; scf->certificate_keys = NGX_CONF_UNSET_PTR; scf->passwords = NGX_CONF_UNSET_PTR; scf->conf_commands = NGX_CONF_UNSET_PTR; scf->prefer_server_ciphers = NGX_CONF_UNSET; scf->verify = NGX_CONF_UNSET_UINT; scf->verify_depth = NGX_CONF_UNSET_UINT; scf->builtin_session_cache = NGX_CONF_UNSET; scf->session_timeout = NGX_CONF_UNSET; scf->session_tickets = NGX_CONF_UNSET; scf->session_ticket_keys = NGX_CONF_UNSET_PTR; 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_TLSv1 |NGX_SSL_TLSv1_1|NGX_SSL_TLSv1_2)); ngx_conf_merge_uint_value(conf->verify, prev->verify, 0); ngx_conf_merge_uint_value(conf->verify_depth, prev->verify_depth, 1); ngx_conf_merge_ptr_value(conf->certificates, prev->certificates, NULL); ngx_conf_merge_ptr_value(conf->certificate_keys, prev->certificate_keys, NULL); ngx_conf_merge_ptr_value(conf->passwords, prev->passwords, NULL); 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->client_certificate, prev->client_certificate, ""); ngx_conf_merge_str_value(conf->trusted_certificate, prev->trusted_certificate, ""); ngx_conf_merge_str_value(conf->crl, prev->crl, ""); ngx_conf_merge_str_value(conf->ciphers, prev->ciphers, NGX_DEFAULT_CIPHERS); ngx_conf_merge_ptr_value(conf->conf_commands, prev->conf_commands, NULL); conf->ssl.log = cf->log; if (conf->listen) { mode = "listen ... ssl"; } else if (conf->enable) { mode = "ssl"; } else if (conf->starttls != NGX_MAIL_STARTTLS_OFF) { mode = "starttls"; } else { return NGX_CONF_OK; } if (conf->file == NULL) { conf->file = prev->file; conf->line = prev->line; } if (conf->certificates == NULL) { 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_keys == NULL) { 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; } if (conf->certificate_keys->nelts < conf->certificates->nelts) { ngx_log_error(NGX_LOG_EMERG, cf->log, 0, "no \"ssl_certificate_key\" is defined " "for certificate \"%V\" and " "the \"%s\" directive in %s:%ui", ((ngx_str_t *) conf->certificates->elts) + conf->certificates->nelts - 1, mode, conf->file, conf->line); 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) { ngx_ssl_cleanup_ctx(&conf->ssl); return NGX_CONF_ERROR; } cln->handler = ngx_ssl_cleanup_ctx; cln->data = &conf->ssl; if (ngx_ssl_certificates(cf, &conf->ssl, conf->certificates, conf->certificate_keys, conf->passwords) != NGX_OK) { return NGX_CONF_ERROR; } if (conf->verify) { if (conf->client_certificate.len == 0 && conf->verify != 3) { ngx_log_error(NGX_LOG_EMERG, cf->log, 0, "no ssl_client_certificate for ssl_verify_client"); return NGX_CONF_ERROR; } if (ngx_ssl_client_certificate(cf, &conf->ssl, &conf->client_certificate, conf->verify_depth) != NGX_OK) { return NGX_CONF_ERROR; } if (ngx_ssl_trusted_certificate(cf, &conf->ssl, &conf->trusted_certificate, conf->verify_depth) != NGX_OK) { return NGX_CONF_ERROR; } if (ngx_ssl_crl(cf, &conf->ssl, &conf->crl) != NGX_OK) { return NGX_CONF_ERROR; } } if (ngx_ssl_ciphers(cf, &conf->ssl, &conf->ciphers, conf->prefer_server_ciphers) != NGX_OK) { return NGX_CONF_ERROR; } 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->certificates, conf->builtin_session_cache, conf->shm_zone, conf->session_timeout) != NGX_OK) { return NGX_CONF_ERROR; } ngx_conf_merge_value(conf->session_tickets, prev->session_tickets, 1); #ifdef SSL_OP_NO_TICKET if (!conf->session_tickets) { SSL_CTX_set_options(conf->ssl.ctx, SSL_OP_NO_TICKET); } #endif ngx_conf_merge_ptr_value(conf->session_ticket_keys, prev->session_ticket_keys, NULL); if (ngx_ssl_session_ticket_keys(cf, &conf->ssl, conf->session_ticket_keys) != NGX_OK) { return NGX_CONF_ERROR; } if (ngx_ssl_conf_commands(cf, &conf->ssl, conf->conf_commands) != 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_EMERG, cf, 0, "\"starttls\" directive conflicts with \"ssl on\""); return NGX_CONF_ERROR; } if (!scf->listen) { 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_EMERG, cf, 0, "\"ssl\" directive conflicts with \"starttls\""); return NGX_CONF_ERROR; } if (!scf->listen) { scf->file = cf->conf_file->file.name.data; scf->line = cf->conf_file->line; } return NGX_CONF_OK; } static char * ngx_mail_ssl_password_file(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_mail_ssl_conf_t *scf = conf; ngx_str_t *value; if (scf->passwords != NGX_CONF_UNSET_PTR) { return "is duplicate"; } value = cf->args->elts; scf->passwords = ngx_ssl_read_password_file(cf, &value[1]); if (scf->passwords == NULL) { return NGX_CONF_ERROR; } 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; } static char * ngx_mail_ssl_conf_command_check(ngx_conf_t *cf, void *post, void *data) { #ifndef SSL_CONF_FLAG_FILE return "is not supported on this platform"; #endif return NGX_CONF_OK; }