ngx_mail_ssl_module.c
/*
* 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 "prime256v1"
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_session_cache(ngx_conf_t *cf, ngx_command_t *cmd,
void *conf);
static ngx_conf_enum_t ngx_http_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_null_string, 0 }
};
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),
NULL },
{ 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_http_starttls_state },
{ ngx_string("ssl_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, certificate),
NULL },
{ ngx_string("ssl_certificate_key"),
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, certificate_key),
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_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_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->protocols = 0;
* scf->certificate = { 0, NULL };
* scf->certificate_key = { 0, NULL };
* scf->dhparam = { 0, NULL };
* scf->ecdh_curve = { 0, NULL };
* scf->ciphers = { 0, NULL };
* scf->shm_zone = NULL;
*/
scf->enable = NGX_CONF_UNSET;
scf->starttls = NGX_CONF_UNSET_UINT;
scf->prefer_server_ciphers = NGX_CONF_UNSET;
scf->builtin_session_cache = NGX_CONF_UNSET;
scf->session_timeout = NGX_CONF_UNSET;
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_SSLv3|NGX_SSL_TLSv1
|NGX_SSL_TLSv1_1|NGX_SSL_TLSv1_2));
ngx_conf_merge_str_value(conf->certificate, prev->certificate, "");
ngx_conf_merge_str_value(conf->certificate_key, prev->certificate_key, "");
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->ciphers, prev->ciphers, NGX_DEFAULT_CIPHERS);
conf->ssl.log = cf->log;
if (conf->enable) {
mode = "ssl";
} else if (conf->starttls != NGX_MAIL_STARTTLS_OFF) {
mode = "starttls";
} else {
mode = "";
}
if (conf->file == NULL) {
conf->file = prev->file;
conf->line = prev->line;
}
if (*mode) {
if (conf->certificate.len == 0) {
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_key.len == 0) {
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;
}
} else {
if (conf->certificate.len == 0) {
return NGX_CONF_OK;
}
if (conf->certificate_key.len == 0) {
ngx_log_error(NGX_LOG_EMERG, cf->log, 0,
"no \"ssl_certificate_key\" is defined "
"for certificate \"%V\"",
&conf->certificate);
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) {
return NGX_CONF_ERROR;
}
cln->handler = ngx_ssl_cleanup_ctx;
cln->data = &conf->ssl;
if (ngx_ssl_certificate(cf, &conf->ssl, &conf->certificate,
&conf->certificate_key)
!= NGX_OK)
{
return NGX_CONF_ERROR;
}
if (conf->ciphers.len) {
if (SSL_CTX_set_cipher_list(conf->ssl.ctx,
(const char *) conf->ciphers.data)
== 0)
{
ngx_ssl_error(NGX_LOG_EMERG, cf->log, 0,
"SSL_CTX_set_cipher_list(\"%V\") failed",
&conf->ciphers);
}
}
if (conf->prefer_server_ciphers) {
SSL_CTX_set_options(conf->ssl.ctx, SSL_OP_CIPHER_SERVER_PREFERENCE);
}
SSL_CTX_set_tmp_rsa_callback(conf->ssl.ctx, ngx_ssl_rsa512_key_callback);
if (ngx_ssl_dhparam(cf, &conf->ssl, &conf->dhparam) != 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->builtin_session_cache,
conf->shm_zone, conf->session_timeout)
!= 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_WARN, cf, 0,
"\"starttls\" directive conflicts with \"ssl on\"");
return NGX_CONF_ERROR;
}
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_WARN, cf, 0,
"\"ssl\" directive conflicts with \"starttls\"");
return NGX_CONF_ERROR;
}
scf->file = cf->conf_file->file.name.data;
scf->line = cf->conf_file->line;
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;
}
