Mercurial > hg > nginx
view src/mail/ngx_mail_handler.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 | 7f955d3b9a0d |
children | da0a85e91587 |
line wrap: on
line source
/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #include <ngx_mail.h> static void ngx_mail_init_session(ngx_connection_t *c); #if (NGX_MAIL_SSL) static void ngx_mail_ssl_init_connection(ngx_ssl_t *ssl, ngx_connection_t *c); static void ngx_mail_ssl_handshake_handler(ngx_connection_t *c); static ngx_int_t ngx_mail_verify_cert(ngx_mail_session_t *s, ngx_connection_t *c); #endif void ngx_mail_init_connection(ngx_connection_t *c) { size_t len; ngx_uint_t i; ngx_mail_port_t *port; struct sockaddr *sa; struct sockaddr_in *sin; ngx_mail_log_ctx_t *ctx; ngx_mail_in_addr_t *addr; ngx_mail_session_t *s; ngx_mail_addr_conf_t *addr_conf; ngx_mail_core_srv_conf_t *cscf; u_char text[NGX_SOCKADDR_STRLEN]; #if (NGX_HAVE_INET6) struct sockaddr_in6 *sin6; ngx_mail_in6_addr_t *addr6; #endif /* find the server configuration for the address:port */ port = c->listening->servers; if (port->naddrs > 1) { /* * There are several addresses on this port and one of them * is the "*:port" wildcard so getsockname() is needed to determine * the server address. * * AcceptEx() already gave this address. */ if (ngx_connection_local_sockaddr(c, NULL, 0) != NGX_OK) { ngx_mail_close_connection(c); return; } sa = c->local_sockaddr; switch (sa->sa_family) { #if (NGX_HAVE_INET6) case AF_INET6: sin6 = (struct sockaddr_in6 *) sa; addr6 = port->addrs; /* the last address is "*" */ for (i = 0; i < port->naddrs - 1; i++) { if (ngx_memcmp(&addr6[i].addr6, &sin6->sin6_addr, 16) == 0) { break; } } addr_conf = &addr6[i].conf; break; #endif default: /* AF_INET */ sin = (struct sockaddr_in *) sa; addr = port->addrs; /* the last address is "*" */ for (i = 0; i < port->naddrs - 1; i++) { if (addr[i].addr == sin->sin_addr.s_addr) { break; } } addr_conf = &addr[i].conf; break; } } else { switch (c->local_sockaddr->sa_family) { #if (NGX_HAVE_INET6) case AF_INET6: addr6 = port->addrs; addr_conf = &addr6[0].conf; break; #endif default: /* AF_INET */ addr = port->addrs; addr_conf = &addr[0].conf; break; } } s = ngx_pcalloc(c->pool, sizeof(ngx_mail_session_t)); if (s == NULL) { ngx_mail_close_connection(c); return; } s->signature = NGX_MAIL_MODULE; s->main_conf = addr_conf->ctx->main_conf; s->srv_conf = addr_conf->ctx->srv_conf; s->addr_text = &addr_conf->addr_text; c->data = s; s->connection = c; cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); ngx_set_connection_log(c, cscf->error_log); len = ngx_sock_ntop(c->sockaddr, c->socklen, text, NGX_SOCKADDR_STRLEN, 1); ngx_log_error(NGX_LOG_INFO, c->log, 0, "*%uA client %*s connected to %V", c->number, len, text, s->addr_text); ctx = ngx_palloc(c->pool, sizeof(ngx_mail_log_ctx_t)); if (ctx == NULL) { ngx_mail_close_connection(c); return; } ctx->client = &c->addr_text; ctx->session = s; c->log->connection = c->number; c->log->handler = ngx_mail_log_error; c->log->data = ctx; c->log->action = "sending client greeting line"; c->log_error = NGX_ERROR_INFO; #if (NGX_MAIL_SSL) { ngx_mail_ssl_conf_t *sslcf; sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module); if (sslcf->enable || addr_conf->ssl) { c->log->action = "SSL handshaking"; ngx_mail_ssl_init_connection(&sslcf->ssl, c); return; } } #endif ngx_mail_init_session(c); } #if (NGX_MAIL_SSL) void ngx_mail_starttls_handler(ngx_event_t *rev) { ngx_connection_t *c; ngx_mail_session_t *s; ngx_mail_ssl_conf_t *sslcf; c = rev->data; s = c->data; s->starttls = 1; c->log->action = "in starttls state"; sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module); ngx_mail_ssl_init_connection(&sslcf->ssl, c); } static void ngx_mail_ssl_init_connection(ngx_ssl_t *ssl, ngx_connection_t *c) { ngx_mail_session_t *s; ngx_mail_core_srv_conf_t *cscf; if (ngx_ssl_create_connection(ssl, c, 0) != NGX_OK) { ngx_mail_close_connection(c); return; } if (ngx_ssl_handshake(c) == NGX_AGAIN) { s = c->data; cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); ngx_add_timer(c->read, cscf->timeout); c->ssl->handler = ngx_mail_ssl_handshake_handler; return; } ngx_mail_ssl_handshake_handler(c); } static void ngx_mail_ssl_handshake_handler(ngx_connection_t *c) { ngx_mail_session_t *s; ngx_mail_core_srv_conf_t *cscf; if (c->ssl->handshaked) { s = c->data; if (ngx_mail_verify_cert(s, c) != NGX_OK) { return; } if (s->starttls) { cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); c->read->handler = cscf->protocol->init_protocol; c->write->handler = ngx_mail_send; cscf->protocol->init_protocol(c->read); return; } c->read->ready = 0; ngx_mail_init_session(c); return; } ngx_mail_close_connection(c); } static ngx_int_t ngx_mail_verify_cert(ngx_mail_session_t *s, ngx_connection_t *c) { long rc; X509 *cert; ngx_mail_ssl_conf_t *sslcf; ngx_mail_core_srv_conf_t *cscf; sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module); if (!sslcf->verify) { return NGX_OK; } rc = SSL_get_verify_result(c->ssl->connection); if (rc != X509_V_OK && (sslcf->verify != 3 || !ngx_ssl_verify_error_optional(rc))) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client SSL certificate verify error: (%l:%s)", rc, X509_verify_cert_error_string(rc)); ngx_ssl_remove_cached_session(c->ssl->session_ctx, (SSL_get0_session(c->ssl->connection))); cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); s->out = cscf->protocol->cert_error; s->quit = 1; c->write->handler = ngx_mail_send; ngx_mail_send(s->connection->write); return NGX_ERROR; } if (sslcf->verify == 1) { cert = SSL_get_peer_certificate(c->ssl->connection); if (cert == NULL) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent no required SSL certificate"); ngx_ssl_remove_cached_session(c->ssl->session_ctx, (SSL_get0_session(c->ssl->connection))); cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); s->out = cscf->protocol->no_cert; s->quit = 1; c->write->handler = ngx_mail_send; ngx_mail_send(s->connection->write); return NGX_ERROR; } X509_free(cert); } return NGX_OK; } #endif static void ngx_mail_init_session(ngx_connection_t *c) { ngx_mail_session_t *s; ngx_mail_core_srv_conf_t *cscf; s = c->data; cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); s->protocol = cscf->protocol->type; s->ctx = ngx_pcalloc(c->pool, sizeof(void *) * ngx_mail_max_module); if (s->ctx == NULL) { ngx_mail_session_internal_server_error(s); return; } c->write->handler = ngx_mail_send; cscf->protocol->init_session(s, c); } ngx_int_t ngx_mail_salt(ngx_mail_session_t *s, ngx_connection_t *c, ngx_mail_core_srv_conf_t *cscf) { s->salt.data = ngx_pnalloc(c->pool, sizeof(" <18446744073709551616.@>" CRLF) - 1 + NGX_TIME_T_LEN + cscf->server_name.len); if (s->salt.data == NULL) { return NGX_ERROR; } s->salt.len = ngx_sprintf(s->salt.data, "<%ul.%T@%V>" CRLF, ngx_random(), ngx_time(), &cscf->server_name) - s->salt.data; return NGX_OK; } #if (NGX_MAIL_SSL) ngx_int_t ngx_mail_starttls_only(ngx_mail_session_t *s, ngx_connection_t *c) { ngx_mail_ssl_conf_t *sslcf; if (c->ssl) { return 0; } sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module); if (sslcf->starttls == NGX_MAIL_STARTTLS_ONLY) { return 1; } return 0; } #endif ngx_int_t ngx_mail_auth_plain(ngx_mail_session_t *s, ngx_connection_t *c, ngx_uint_t n) { u_char *p, *last; ngx_str_t *arg, plain; arg = s->args.elts; #if (NGX_DEBUG_MAIL_PASSWD) ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth plain: \"%V\"", &arg[n]); #endif plain.data = ngx_pnalloc(c->pool, ngx_base64_decoded_length(arg[n].len)); if (plain.data == NULL) { return NGX_ERROR; } if (ngx_decode_base64(&plain, &arg[n]) != NGX_OK) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent invalid base64 encoding in AUTH PLAIN command"); return NGX_MAIL_PARSE_INVALID_COMMAND; } p = plain.data; last = p + plain.len; while (p < last && *p++) { /* void */ } if (p == last) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent invalid login in AUTH PLAIN command"); return NGX_MAIL_PARSE_INVALID_COMMAND; } s->login.data = p; while (p < last && *p) { p++; } if (p == last) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent invalid password in AUTH PLAIN command"); return NGX_MAIL_PARSE_INVALID_COMMAND; } s->login.len = p++ - s->login.data; s->passwd.len = last - p; s->passwd.data = p; #if (NGX_DEBUG_MAIL_PASSWD) ngx_log_debug2(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth plain: \"%V\" \"%V\"", &s->login, &s->passwd); #endif return NGX_DONE; } ngx_int_t ngx_mail_auth_login_username(ngx_mail_session_t *s, ngx_connection_t *c, ngx_uint_t n) { ngx_str_t *arg; arg = s->args.elts; ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth login username: \"%V\"", &arg[n]); s->login.data = ngx_pnalloc(c->pool, ngx_base64_decoded_length(arg[n].len)); if (s->login.data == NULL) { return NGX_ERROR; } if (ngx_decode_base64(&s->login, &arg[n]) != NGX_OK) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent invalid base64 encoding in AUTH LOGIN command"); return NGX_MAIL_PARSE_INVALID_COMMAND; } ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth login username: \"%V\"", &s->login); return NGX_OK; } ngx_int_t ngx_mail_auth_login_password(ngx_mail_session_t *s, ngx_connection_t *c) { ngx_str_t *arg; arg = s->args.elts; #if (NGX_DEBUG_MAIL_PASSWD) ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth login password: \"%V\"", &arg[0]); #endif s->passwd.data = ngx_pnalloc(c->pool, ngx_base64_decoded_length(arg[0].len)); if (s->passwd.data == NULL) { return NGX_ERROR; } if (ngx_decode_base64(&s->passwd, &arg[0]) != NGX_OK) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent invalid base64 encoding in AUTH LOGIN command"); return NGX_MAIL_PARSE_INVALID_COMMAND; } #if (NGX_DEBUG_MAIL_PASSWD) ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth login password: \"%V\"", &s->passwd); #endif return NGX_DONE; } ngx_int_t ngx_mail_auth_cram_md5_salt(ngx_mail_session_t *s, ngx_connection_t *c, char *prefix, size_t len) { u_char *p; ngx_str_t salt; ngx_uint_t n; p = ngx_pnalloc(c->pool, len + ngx_base64_encoded_length(s->salt.len) + 2); if (p == NULL) { return NGX_ERROR; } salt.data = ngx_cpymem(p, prefix, len); s->salt.len -= 2; ngx_encode_base64(&salt, &s->salt); s->salt.len += 2; n = len + salt.len; p[n++] = CR; p[n++] = LF; s->out.len = n; s->out.data = p; return NGX_OK; } ngx_int_t ngx_mail_auth_cram_md5(ngx_mail_session_t *s, ngx_connection_t *c) { u_char *p, *last; ngx_str_t *arg; arg = s->args.elts; ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth cram-md5: \"%V\"", &arg[0]); s->login.data = ngx_pnalloc(c->pool, ngx_base64_decoded_length(arg[0].len)); if (s->login.data == NULL) { return NGX_ERROR; } if (ngx_decode_base64(&s->login, &arg[0]) != NGX_OK) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent invalid base64 encoding in AUTH CRAM-MD5 command"); return NGX_MAIL_PARSE_INVALID_COMMAND; } p = s->login.data; last = p + s->login.len; while (p < last) { if (*p++ == ' ') { s->login.len = p - s->login.data - 1; s->passwd.len = last - p; s->passwd.data = p; break; } } if (s->passwd.len != 32) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent invalid CRAM-MD5 hash in AUTH CRAM-MD5 command"); return NGX_MAIL_PARSE_INVALID_COMMAND; } ngx_log_debug2(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth cram-md5: \"%V\" \"%V\"", &s->login, &s->passwd); s->auth_method = NGX_MAIL_AUTH_CRAM_MD5; return NGX_DONE; } ngx_int_t ngx_mail_auth_external(ngx_mail_session_t *s, ngx_connection_t *c, ngx_uint_t n) { ngx_str_t *arg, external; arg = s->args.elts; ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth external: \"%V\"", &arg[n]); external.data = ngx_pnalloc(c->pool, ngx_base64_decoded_length(arg[n].len)); if (external.data == NULL) { return NGX_ERROR; } if (ngx_decode_base64(&external, &arg[n]) != NGX_OK) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent invalid base64 encoding in AUTH EXTERNAL command"); return NGX_MAIL_PARSE_INVALID_COMMAND; } s->login.len = external.len; s->login.data = external.data; ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth external: \"%V\"", &s->login); s->auth_method = NGX_MAIL_AUTH_EXTERNAL; return NGX_DONE; } void ngx_mail_send(ngx_event_t *wev) { ngx_int_t n; ngx_connection_t *c; ngx_mail_session_t *s; ngx_mail_core_srv_conf_t *cscf; c = wev->data; s = c->data; if (wev->timedout) { ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out"); c->timedout = 1; ngx_mail_close_connection(c); return; } if (s->out.len == 0) { if (ngx_handle_write_event(c->write, 0) != NGX_OK) { ngx_mail_close_connection(c); } return; } n = c->send(c, s->out.data, s->out.len); if (n > 0) { s->out.data += n; s->out.len -= n; if (s->out.len != 0) { goto again; } if (wev->timer_set) { ngx_del_timer(wev); } if (s->quit) { ngx_mail_close_connection(c); return; } if (s->blocked) { c->read->handler(c->read); } return; } if (n == NGX_ERROR) { ngx_mail_close_connection(c); return; } /* n == NGX_AGAIN */ again: cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); ngx_add_timer(c->write, cscf->timeout); if (ngx_handle_write_event(c->write, 0) != NGX_OK) { ngx_mail_close_connection(c); return; } } ngx_int_t ngx_mail_read_command(ngx_mail_session_t *s, ngx_connection_t *c) { ssize_t n; ngx_int_t rc; ngx_str_t l; ngx_mail_core_srv_conf_t *cscf; n = c->recv(c, s->buffer->last, s->buffer->end - s->buffer->last); if (n == NGX_ERROR || n == 0) { ngx_mail_close_connection(c); return NGX_ERROR; } if (n > 0) { s->buffer->last += n; } if (n == NGX_AGAIN) { if (ngx_handle_read_event(c->read, 0) != NGX_OK) { ngx_mail_session_internal_server_error(s); return NGX_ERROR; } if (s->buffer->pos == s->buffer->last) { return NGX_AGAIN; } } cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); rc = cscf->protocol->parse_command(s); if (rc == NGX_AGAIN) { if (s->buffer->last < s->buffer->end) { return rc; } l.len = s->buffer->last - s->buffer->start; l.data = s->buffer->start; ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent too long command \"%V\"", &l); s->quit = 1; return NGX_MAIL_PARSE_INVALID_COMMAND; } if (rc == NGX_IMAP_NEXT || rc == NGX_MAIL_PARSE_INVALID_COMMAND) { return rc; } if (rc == NGX_ERROR) { ngx_mail_close_connection(c); return NGX_ERROR; } return NGX_OK; } void ngx_mail_auth(ngx_mail_session_t *s, ngx_connection_t *c) { s->args.nelts = 0; if (s->buffer->pos == s->buffer->last) { s->buffer->pos = s->buffer->start; s->buffer->last = s->buffer->start; } s->state = 0; if (c->read->timer_set) { ngx_del_timer(c->read); } s->login_attempt++; ngx_mail_auth_http_init(s); } void ngx_mail_session_internal_server_error(ngx_mail_session_t *s) { ngx_mail_core_srv_conf_t *cscf; cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); s->out = cscf->protocol->internal_server_error; s->quit = 1; ngx_mail_send(s->connection->write); } void ngx_mail_close_connection(ngx_connection_t *c) { ngx_pool_t *pool; ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "close mail connection: %d", c->fd); #if (NGX_MAIL_SSL) if (c->ssl) { if (ngx_ssl_shutdown(c) == NGX_AGAIN) { c->ssl->handler = ngx_mail_close_connection; return; } } #endif #if (NGX_STAT_STUB) (void) ngx_atomic_fetch_add(ngx_stat_active, -1); #endif c->destroyed = 1; pool = c->pool; ngx_close_connection(c); ngx_destroy_pool(pool); } u_char * ngx_mail_log_error(ngx_log_t *log, u_char *buf, size_t len) { u_char *p; ngx_mail_session_t *s; ngx_mail_log_ctx_t *ctx; if (log->action) { p = ngx_snprintf(buf, len, " while %s", log->action); len -= p - buf; buf = p; } ctx = log->data; p = ngx_snprintf(buf, len, ", client: %V", ctx->client); len -= p - buf; buf = p; s = ctx->session; if (s == NULL) { return p; } p = ngx_snprintf(buf, len, "%s, server: %V", s->starttls ? " using starttls" : "", s->addr_text); len -= p - buf; buf = p; if (s->login.len == 0) { return p; } p = ngx_snprintf(buf, len, ", login: \"%V\"", &s->login); len -= p - buf; buf = p; if (s->proxy == NULL) { return p; } p = ngx_snprintf(buf, len, ", upstream: %V", s->proxy->upstream.name); return p; }