SSL: ssl_conf_command directive.

With the ssl_conf_command directive it is now possible to set arbitrary OpenSSL configuration parameters as long as nginx is compiled with OpenSSL 1.0.2 or later. Full list of available configuration commands can be found in the SSL_CONF_cmd manual page (https://www.openssl.org/docs/man1.1.1/man3/SSL_CONF_cmd.html). In particular, this allows configuring PrioritizeChaCha option (ticket #1445): ssl_conf_command Options PrioritizeChaCha; It can be also used to configure TLSv1.3 ciphers in OpenSSL, which fails to configure them via the SSL_CTX_set_cipher_list() interface (ticket #1529): ssl_conf_command Ciphersuites TLS_CHACHA20_POLY1305_SHA256; Configuration commands are applied after nginx own configuration for SSL, so they can be used to override anything set by nginx. Note though that configuring OpenSSL directly with ssl_conf_command might result in a behaviour nginx does not expect, and should be done with care.
VKCOM · Oct 22, 2020 · 3f3d429 · 3f3d429
1 parent 23a5335
commit 3f3d429
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diff --git a/src/event/ngx_event_openssl.c b/src/event/ngx_event_openssl.c
@@ -1470,6 +1470,78 @@ ngx_ssl_early_data(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_uint_t enable)
 }
 
 
+ngx_int_t
+ngx_ssl_conf_commands(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_array_t *commands)
+{
+    if (commands == NULL) {
+        return NGX_OK;
+    }
+
+#ifdef SSL_CONF_FLAG_FILE
+    {
+    int            type;
+    u_char        *key, *value;
+    ngx_uint_t     i;
+    ngx_keyval_t  *cmd;
+    SSL_CONF_CTX  *cctx;
+
+    cctx = SSL_CONF_CTX_new();
+    if (cctx == NULL) {
+        ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
+                      "SSL_CONF_CTX_new() failed");
+        return NGX_ERROR;
+    }
+
+    SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_FILE);
+    SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_SERVER);
+    SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_CLIENT);
+    SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_CERTIFICATE);
+    SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_SHOW_ERRORS);
+
+    SSL_CONF_CTX_set_ssl_ctx(cctx, ssl->ctx);
+
+    cmd = commands->elts;
+    for (i = 0; i < commands->nelts; i++) {
+
+        key = cmd[i].key.data;
+        type = SSL_CONF_cmd_value_type(cctx, (char *) key);
+
+        if (type == SSL_CONF_TYPE_FILE || type == SSL_CONF_TYPE_DIR) {
+            if (ngx_conf_full_name(cf->cycle, &cmd[i].value, 1) != NGX_OK) {
+                SSL_CONF_CTX_free(cctx);
+                return NGX_ERROR;
+            }
+        }
+
+        value = cmd[i].value.data;
+
+        if (SSL_CONF_cmd(cctx, (char *) key, (char *) value) <= 0) {
+            ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
+                          "SSL_CONF_cmd(\"%s\", \"%s\") failed", key, value);
+            SSL_CONF_CTX_free(cctx);
+            return NGX_ERROR;
+        }
+    }
+
+    if (SSL_CONF_CTX_finish(cctx) != 1) {
+        ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
+                      "SSL_CONF_finish() failed");
+        SSL_CONF_CTX_free(cctx);
+        return NGX_ERROR;
+    }
+
+    SSL_CONF_CTX_free(cctx);
+
+    return NGX_OK;
+    }
+#else
+    ngx_log_error(NGX_LOG_EMERG, ssl->log, 0,
+                  "SSL_CONF_cmd() is not available on this platform");
+    return NGX_ERROR;
+#endif
+}
+
+
 ngx_int_t
 ngx_ssl_client_session_cache(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_uint_t enable)
 {

diff --git a/src/event/ngx_event_openssl.h b/src/event/ngx_event_openssl.h
@@ -203,6 +203,9 @@ ngx_int_t ngx_ssl_dhparam(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *file);
 ngx_int_t ngx_ssl_ecdh_curve(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *name);
 ngx_int_t ngx_ssl_early_data(ngx_conf_t *cf, ngx_ssl_t *ssl,
     ngx_uint_t enable);
+ngx_int_t ngx_ssl_conf_commands(ngx_conf_t *cf, ngx_ssl_t *ssl,
+    ngx_array_t *commands);
+
 ngx_int_t ngx_ssl_client_session_cache(ngx_conf_t *cf, ngx_ssl_t *ssl,
     ngx_uint_t enable);
 ngx_int_t ngx_ssl_session_cache(ngx_ssl_t *ssl, ngx_str_t *sess_ctx,
@@ -211,6 +214,7 @@ ngx_int_t ngx_ssl_session_cache(ngx_ssl_t *ssl, ngx_str_t *sess_ctx,
 ngx_int_t ngx_ssl_session_ticket_keys(ngx_conf_t *cf, ngx_ssl_t *ssl,
     ngx_array_t *paths);
 ngx_int_t ngx_ssl_session_cache_init(ngx_shm_zone_t *shm_zone, void *data);
+
 ngx_int_t ngx_ssl_create_connection(ngx_ssl_t *ssl, ngx_connection_t *c,
     ngx_uint_t flags);
 

diff --git a/src/http/modules/ngx_http_ssl_module.c b/src/http/modules/ngx_http_ssl_module.c
@@ -53,6 +53,9 @@ static char *ngx_http_ssl_session_cache(ngx_conf_t *cf, ngx_command_t *cmd,
 static char *ngx_http_ssl_ocsp_cache(ngx_conf_t *cf, ngx_command_t *cmd,
     void *conf);
 
+static char *ngx_http_ssl_conf_command_check(ngx_conf_t *cf, void *post,
+    void *data);
+
 static ngx_int_t ngx_http_ssl_init(ngx_conf_t *cf);
 
 
@@ -89,6 +92,10 @@ static ngx_conf_deprecated_t  ngx_http_ssl_deprecated = {
 };
 
 
+static ngx_conf_post_t  ngx_http_ssl_conf_command_post =
+    { ngx_http_ssl_conf_command_check };
+
+
 static ngx_command_t  ngx_http_ssl_commands[] = {
 
     { ngx_string("ssl"),
@@ -280,6 +287,13 @@ static ngx_command_t  ngx_http_ssl_commands[] = {
       offsetof(ngx_http_ssl_srv_conf_t, early_data),
       NULL },
 
+    { ngx_string("ssl_conf_command"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE2,
+      ngx_conf_set_keyval_slot,
+      NGX_HTTP_SRV_CONF_OFFSET,
+      offsetof(ngx_http_ssl_srv_conf_t, conf_commands),
+      &ngx_http_ssl_conf_command_post },
+
       ngx_null_command
 };
 
@@ -606,6 +620,7 @@ ngx_http_ssl_create_srv_conf(ngx_conf_t *cf)
     sscf->certificates = NGX_CONF_UNSET_PTR;
     sscf->certificate_keys = NGX_CONF_UNSET_PTR;
     sscf->passwords = NGX_CONF_UNSET_PTR;
+    sscf->conf_commands = NGX_CONF_UNSET_PTR;
     sscf->builtin_session_cache = NGX_CONF_UNSET;
     sscf->session_timeout = NGX_CONF_UNSET;
     sscf->session_tickets = NGX_CONF_UNSET;
@@ -675,6 +690,8 @@ ngx_http_ssl_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child)
 
     ngx_conf_merge_str_value(conf->ciphers, prev->ciphers, NGX_DEFAULT_CIPHERS);
 
+    ngx_conf_merge_ptr_value(conf->conf_commands, prev->conf_commands, NULL);
+
     ngx_conf_merge_uint_value(conf->ocsp, prev->ocsp, 0);
     ngx_conf_merge_str_value(conf->ocsp_responder, prev->ocsp_responder, "");
     ngx_conf_merge_ptr_value(conf->ocsp_cache_zone,
@@ -913,6 +930,10 @@ ngx_http_ssl_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child)
         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;
 }
 
@@ -1235,6 +1256,17 @@ ngx_http_ssl_ocsp_cache(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
 }
 
 
+static char *
+ngx_http_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;
+}
+
+
 static ngx_int_t
 ngx_http_ssl_init(ngx_conf_t *cf)
 {

diff --git a/src/http/modules/ngx_http_ssl_module.h b/src/http/modules/ngx_http_ssl_module.h
@@ -48,6 +48,7 @@ typedef struct {
     ngx_str_t                       ciphers;
 
     ngx_array_t                    *passwords;
+    ngx_array_t                    *conf_commands;
 
     ngx_shm_zone_t                 *shm_zone;
 

diff --git a/src/mail/ngx_mail_ssl_module.c b/src/mail/ngx_mail_ssl_module.c
@@ -26,6 +26,9 @@ static char *ngx_mail_ssl_password_file(ngx_conf_t *cf, ngx_command_t *cmd,
 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 },
@@ -61,6 +64,10 @@ static ngx_conf_deprecated_t  ngx_mail_ssl_deprecated = {
 };
 
 
+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"),
@@ -196,6 +203,13 @@ static ngx_command_t  ngx_mail_ssl_commands[] = {
       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
 };
 
@@ -259,6 +273,7 @@ ngx_mail_ssl_create_conf(ngx_conf_t *cf)
     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;
@@ -316,6 +331,8 @@ ngx_mail_ssl_merge_conf(ngx_conf_t *cf, void *parent, void *child)
 
     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;
 
@@ -461,6 +478,10 @@ ngx_mail_ssl_merge_conf(ngx_conf_t *cf, void *parent, void *child)
         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;
 }
 
@@ -654,3 +675,14 @@ ngx_mail_ssl_session_cache(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
 
     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;
+}
diff --git a/src/mail/ngx_mail_ssl_module.h b/src/mail/ngx_mail_ssl_module.h
@@ -48,6 +48,7 @@ typedef struct {
     ngx_str_t        ciphers;
 
     ngx_array_t     *passwords;
+    ngx_array_t     *conf_commands;
 
     ngx_shm_zone_t  *shm_zone;
 

diff --git a/src/stream/ngx_stream_ssl_module.c b/src/stream/ngx_stream_ssl_module.c
@@ -45,6 +45,10 @@ static char *ngx_stream_ssl_password_file(ngx_conf_t *cf, ngx_command_t *cmd,
     void *conf);
 static char *ngx_stream_ssl_session_cache(ngx_conf_t *cf, ngx_command_t *cmd,
     void *conf);
+
+static char *ngx_stream_ssl_conf_command_check(ngx_conf_t *cf, void *post,
+    void *data);
+
 static ngx_int_t ngx_stream_ssl_init(ngx_conf_t *cf);
 
 
@@ -68,6 +72,10 @@ static ngx_conf_enum_t  ngx_stream_ssl_verify[] = {
 };
 
 
+static ngx_conf_post_t  ngx_stream_ssl_conf_command_post =
+    { ngx_stream_ssl_conf_command_check };
+
+
 static ngx_command_t  ngx_stream_ssl_commands[] = {
 
     { ngx_string("ssl_handshake_timeout"),
@@ -196,6 +204,13 @@ static ngx_command_t  ngx_stream_ssl_commands[] = {
       offsetof(ngx_stream_ssl_conf_t, crl),
       NULL },
 
+    { ngx_string("ssl_conf_command"),
+      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE2,
+      ngx_conf_set_keyval_slot,
+      NGX_STREAM_SRV_CONF_OFFSET,
+      offsetof(ngx_stream_ssl_conf_t, conf_commands),
+      &ngx_stream_ssl_conf_command_post },
+
       ngx_null_command
 };
 
@@ -595,6 +610,7 @@ ngx_stream_ssl_create_conf(ngx_conf_t *cf)
     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;
@@ -650,6 +666,8 @@ ngx_stream_ssl_merge_conf(ngx_conf_t *cf, void *parent, void *child)
 
     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;
 
@@ -811,6 +829,10 @@ ngx_stream_ssl_merge_conf(ngx_conf_t *cf, void *parent, void *child)
         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;
 }
 
@@ -1034,6 +1056,17 @@ ngx_stream_ssl_session_cache(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
 }
 
 
+static char *
+ngx_stream_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;
+}
+
+
 static ngx_int_t
 ngx_stream_ssl_init(ngx_conf_t *cf)
 {

diff --git a/src/stream/ngx_stream_ssl_module.h b/src/stream/ngx_stream_ssl_module.h
@@ -46,6 +46,7 @@ typedef struct {
     ngx_str_t        ciphers;
 
     ngx_array_t     *passwords;
+    ngx_array_t     *conf_commands;
 
     ngx_shm_zone_t  *shm_zone;