]> git.kaiwu.me - nginx.git/commitdiff
SSL: added ability to set keys used for Session Tickets (RFC5077).
authorPiotr Sikora <piotr@cloudflare.com>
Fri, 11 Oct 2013 23:05:24 +0000 (16:05 -0700)
committerPiotr Sikora <piotr@cloudflare.com>
Fri, 11 Oct 2013 23:05:24 +0000 (16:05 -0700)
In order to support key rollover, ssl_session_ticket_key can be defined
multiple times. The first key will be used to issue and resume Session
Tickets, while the rest will be used only to resume them.

    ssl_session_ticket_key  session_tickets/current.key;
    ssl_session_ticket_key  session_tickets/prev-1h.key;
    ssl_session_ticket_key  session_tickets/prev-2h.key;

Please note that nginx supports Session Tickets even without explicit
configuration of the keys and this feature should be only used in setups
where SSL traffic is distributed across multiple nginx servers.

Signed-off-by: Piotr Sikora <piotr@cloudflare.com>
src/event/ngx_event_openssl.c
src/event/ngx_event_openssl.h
src/http/modules/ngx_http_ssl_module.c
src/http/modules/ngx_http_ssl_module.h
src/mail/ngx_mail_ssl_module.c
src/mail/ngx_mail_ssl_module.h

index 6a3a2b5db8cc12453954d997c380e88b7e47f3b5..e4bc1a2c774eb3e4d4815f20d7b94fef664f8c25 100644 (file)
@@ -38,6 +38,12 @@ static void ngx_ssl_expire_sessions(ngx_ssl_session_cache_t *cache,
 static void ngx_ssl_session_rbtree_insert_value(ngx_rbtree_node_t *temp,
     ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel);
 
+#ifdef SSL_CTRL_SET_TLSEXT_TICKET_KEY_CB
+static int ngx_ssl_session_ticket_key_callback(ngx_ssl_conn_t *ssl_conn,
+    unsigned char *name, unsigned char *iv, EVP_CIPHER_CTX *ectx,
+    HMAC_CTX *hctx, int enc);
+#endif
+
 static void *ngx_openssl_create_conf(ngx_cycle_t *cycle);
 static char *ngx_openssl_engine(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
 static void ngx_openssl_exit(ngx_cycle_t *cycle);
@@ -82,6 +88,7 @@ ngx_module_t  ngx_openssl_module = {
 int  ngx_ssl_connection_index;
 int  ngx_ssl_server_conf_index;
 int  ngx_ssl_session_cache_index;
+int  ngx_ssl_session_ticket_keys_index;
 int  ngx_ssl_certificate_index;
 int  ngx_ssl_stapling_index;
 
@@ -139,6 +146,14 @@ ngx_ssl_init(ngx_log_t *log)
         return NGX_ERROR;
     }
 
+    ngx_ssl_session_ticket_keys_index = SSL_CTX_get_ex_new_index(0, NULL, NULL,
+                                                                 NULL, NULL);
+    if (ngx_ssl_session_ticket_keys_index == -1) {
+        ngx_ssl_error(NGX_LOG_ALERT, log, 0,
+                      "SSL_CTX_get_ex_new_index() failed");
+        return NGX_ERROR;
+    }
+
     ngx_ssl_certificate_index = SSL_CTX_get_ex_new_index(0, NULL, NULL, NULL,
                                                          NULL);
     if (ngx_ssl_certificate_index == -1) {
@@ -2240,6 +2255,218 @@ ngx_ssl_session_rbtree_insert_value(ngx_rbtree_node_t *temp,
 }
 
 
+#ifdef SSL_CTRL_SET_TLSEXT_TICKET_KEY_CB
+
+ngx_int_t
+ngx_ssl_session_ticket_keys(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_array_t *paths)
+{
+    u_char                         buf[48];
+    ssize_t                        n;
+    ngx_str_t                     *path;
+    ngx_file_t                     file;
+    ngx_uint_t                     i;
+    ngx_array_t                   *keys;
+    ngx_file_info_t                fi;
+    ngx_ssl_session_ticket_key_t  *key;
+
+    if (paths == NULL) {
+        return NGX_OK;
+    }
+
+    keys = ngx_array_create(cf->pool, paths->nelts,
+                            sizeof(ngx_ssl_session_ticket_key_t));
+    if (keys == NULL) {
+        return NGX_ERROR;
+    }
+
+    path = paths->elts;
+    for (i = 0; i < paths->nelts; i++) {
+
+        if (ngx_conf_full_name(cf->cycle, &path[i], 1) != NGX_OK) {
+            return NGX_ERROR;
+        }
+
+        ngx_memzero(&file, sizeof(ngx_file_t));
+        file.name = path[i];
+        file.log = cf->log;
+
+        file.fd = ngx_open_file(file.name.data, NGX_FILE_RDONLY, 0, 0);
+        if (file.fd == NGX_INVALID_FILE) {
+            ngx_conf_log_error(NGX_LOG_EMERG, cf, ngx_errno,
+                               ngx_open_file_n " \"%V\" failed", &file.name);
+            return NGX_ERROR;
+        }
+
+        if (ngx_fd_info(file.fd, &fi) == NGX_FILE_ERROR) {
+            ngx_conf_log_error(NGX_LOG_CRIT, cf, ngx_errno,
+                               ngx_fd_info_n " \"%V\" failed", &file.name);
+            goto failed;
+        }
+
+        if (ngx_file_size(&fi) != 48) {
+            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
+                               "\"%V\" must be 48 bytes", &file.name);
+            goto failed;
+        }
+
+        n = ngx_read_file(&file, buf, 48, 0);
+
+        if (n == NGX_ERROR) {
+            ngx_conf_log_error(NGX_LOG_CRIT, cf, ngx_errno,
+                               ngx_read_file_n " \"%V\" failed", &file.name);
+            goto failed;
+        }
+
+        if (n != 48) {
+            ngx_conf_log_error(NGX_LOG_CRIT, cf, 0,
+                               ngx_read_file_n " \"%V\" returned only "
+                               "%z bytes instead of 48", &file.name, n);
+            goto failed;
+        }
+
+        key = ngx_array_push(keys);
+        if (key == NULL) {
+            goto failed;
+        }
+
+        ngx_memcpy(key->name, buf, 16);
+        ngx_memcpy(key->aes_key, buf + 16, 16);
+        ngx_memcpy(key->hmac_key, buf + 32, 16);
+
+        if (ngx_close_file(file.fd) == NGX_FILE_ERROR) {
+            ngx_log_error(NGX_LOG_ALERT, cf->log, ngx_errno,
+                          ngx_close_file_n " \"%V\" failed", &file.name);
+        }
+    }
+
+    if (SSL_CTX_set_ex_data(ssl->ctx, ngx_ssl_session_ticket_keys_index, keys)
+        == 0)
+    {
+        ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
+                      "SSL_CTX_set_ex_data() failed");
+        return NGX_ERROR;
+    }
+
+    if (SSL_CTX_set_tlsext_ticket_key_cb(ssl->ctx,
+                                         ngx_ssl_session_ticket_key_callback)
+        == 0)
+    {
+        ngx_log_error(NGX_LOG_WARN, cf->log, 0,
+                      "nginx was built with Session Tickets support, however, "
+                      "now it is linked dynamically to an OpenSSL library "
+                      "which has no tlsext support, therefore Session Tickets "
+                      "are not available");
+    }
+
+    return NGX_OK;
+
+failed:
+
+    if (ngx_close_file(file.fd) == NGX_FILE_ERROR) {
+        ngx_log_error(NGX_LOG_ALERT, cf->log, ngx_errno,
+                      ngx_close_file_n " \"%V\" failed", &file.name);
+    }
+
+    return NGX_ERROR;
+}
+
+
+#ifdef OPENSSL_NO_SHA256
+#define ngx_ssl_session_ticket_md  EVP_sha1
+#else
+#define ngx_ssl_session_ticket_md  EVP_sha256
+#endif
+
+
+static int
+ngx_ssl_session_ticket_key_callback(ngx_ssl_conn_t *ssl_conn,
+    unsigned char *name, unsigned char *iv, EVP_CIPHER_CTX *ectx,
+    HMAC_CTX *hctx, int enc)
+{
+    SSL_CTX                       *ssl_ctx;
+    ngx_uint_t                     i;
+    ngx_array_t                   *keys;
+    ngx_ssl_session_ticket_key_t  *key;
+#if (NGX_DEBUG)
+    u_char                         buf[32];
+    ngx_connection_t              *c;
+#endif
+
+    ssl_ctx = SSL_get_SSL_CTX(ssl_conn);
+
+    keys = SSL_CTX_get_ex_data(ssl_ctx, ngx_ssl_session_ticket_keys_index);
+    if (keys == NULL) {
+        return -1;
+    }
+
+    key = keys->elts;
+
+#if (NGX_DEBUG)
+    c = ngx_ssl_get_connection(ssl_conn);
+#endif
+
+    if (enc == 1) {
+        /* encrypt session ticket */
+
+        ngx_log_debug3(NGX_LOG_DEBUG_HTTP, c->log, 0,
+                       "ssl session ticket encrypt, key: \"%*s\" (%s session)",
+                       ngx_hex_dump(buf, key[0].name, 16) - buf, buf,
+                       SSL_session_reused(ssl_conn) ? "reused" : "new");
+
+        RAND_pseudo_bytes(iv, 16);
+        EVP_EncryptInit_ex(ectx, EVP_aes_128_cbc(), NULL, key[0].aes_key, iv);
+        HMAC_Init_ex(hctx, key[0].hmac_key, 16,
+                     ngx_ssl_session_ticket_md(), NULL);
+        memcpy(name, key[0].name, 16);
+
+        return 0;
+
+    } else {
+        /* decrypt session ticket */
+
+        for (i = 0; i < keys->nelts; i++) {
+            if (ngx_memcmp(name, key[i].name, 16) == 0) {
+                goto found;
+            }
+        }
+
+        ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0,
+                       "ssl session ticket decrypt, key: \"%*s\" not found",
+                       ngx_hex_dump(buf, name, 16) - buf, buf);
+
+        return 0;
+
+    found:
+
+        ngx_log_debug3(NGX_LOG_DEBUG_HTTP, c->log, 0,
+                       "ssl session ticket decrypt, key: \"%*s\"%s",
+                       ngx_hex_dump(buf, key[i].name, 16) - buf, buf,
+                       (i == 0) ? " (default)" : "");
+
+        HMAC_Init_ex(hctx, key[i].hmac_key, 16,
+                     ngx_ssl_session_ticket_md(), NULL);
+        EVP_DecryptInit_ex(ectx, EVP_aes_128_cbc(), NULL, key[i].aes_key, iv);
+
+        return (i == 0) ? 1 : 2 /* renew */;
+    }
+}
+
+#else
+
+ngx_int_t
+ngx_ssl_session_ticket_keys(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_array_t *paths)
+{
+    if (paths) {
+        ngx_log_error(NGX_LOG_WARN, ssl->log, 0,
+                      "\"ssl_session_ticket_keys\" ignored, not supported");
+    }
+
+    return NGX_OK;
+}
+
+#endif
+
+
 void
 ngx_ssl_cleanup_ctx(void *data)
 {
index cca01c67947f4cd8e3add9931bf24d7044377732..841e825698e7acd9d44d1291bd9eb422be0f911a 100644 (file)
@@ -83,6 +83,16 @@ typedef struct {
 } ngx_ssl_session_cache_t;
 
 
+#ifdef SSL_CTRL_SET_TLSEXT_TICKET_KEY_CB
+
+typedef struct {
+    u_char                      name[16];
+    u_char                      aes_key[16];
+    u_char                      hmac_key[16];
+} ngx_ssl_session_ticket_key_t;
+
+#endif
+
 
 #define NGX_SSL_SSLv2    0x0002
 #define NGX_SSL_SSLv3    0x0004
@@ -116,6 +126,8 @@ 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_session_cache(ngx_ssl_t *ssl, ngx_str_t *sess_ctx,
     ssize_t builtin_session_cache, ngx_shm_zone_t *shm_zone, time_t timeout);
+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);
@@ -173,6 +185,7 @@ void ngx_ssl_cleanup_ctx(void *data);
 extern int  ngx_ssl_connection_index;
 extern int  ngx_ssl_server_conf_index;
 extern int  ngx_ssl_session_cache_index;
+extern int  ngx_ssl_session_ticket_keys_index;
 extern int  ngx_ssl_certificate_index;
 extern int  ngx_ssl_stapling_index;
 
index 75dd7f4b041a2336a4ca90a967f8c371d0c0e3a7..7ac96c6216ec2d0af1b549fa1a65682d8dfcbb6c 100644 (file)
@@ -153,6 +153,13 @@ static ngx_command_t  ngx_http_ssl_commands[] = {
       0,
       NULL },
 
+    { ngx_string("ssl_session_ticket_key"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_str_array_slot,
+      NGX_HTTP_SRV_CONF_OFFSET,
+      offsetof(ngx_http_ssl_srv_conf_t, session_ticket_keys),
+      NULL },
+
     { ngx_string("ssl_session_timeout"),
       NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
       ngx_conf_set_sec_slot,
@@ -421,6 +428,7 @@ ngx_http_ssl_create_srv_conf(ngx_conf_t *cf)
     sscf->verify_depth = NGX_CONF_UNSET_UINT;
     sscf->builtin_session_cache = NGX_CONF_UNSET;
     sscf->session_timeout = NGX_CONF_UNSET;
+    sscf->session_ticket_keys = NGX_CONF_UNSET_PTR;
     sscf->stapling = NGX_CONF_UNSET;
     sscf->stapling_verify = NGX_CONF_UNSET;
 
@@ -623,6 +631,15 @@ ngx_http_ssl_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child)
         return NGX_CONF_ERROR;
     }
 
+    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 (conf->stapling) {
 
         if (ngx_ssl_stapling(cf, &conf->ssl, &conf->stapling_file,
index c4c576ef63be9c51f4af06faa4c38890e8cd78fd..3feb4b6d27b21ec377b1475b61e9195c25ad08f2 100644 (file)
@@ -42,6 +42,8 @@ typedef struct {
 
     ngx_shm_zone_t                 *shm_zone;
 
+    ngx_array_t                    *session_ticket_keys;
+
     ngx_flag_t                      stapling;
     ngx_flag_t                      stapling_verify;
     ngx_str_t                       stapling_file;
index 18fd66aed3a35b406d8eb151d662f17ad14e729a..94c015700e78a3761e40dd326fc7aad4073c005c 100644 (file)
@@ -116,6 +116,13 @@ static ngx_command_t  ngx_mail_ssl_commands[] = {
       0,
       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,
@@ -184,6 +191,7 @@ ngx_mail_ssl_create_conf(ngx_conf_t *cf)
     scf->prefer_server_ciphers = NGX_CONF_UNSET;
     scf->builtin_session_cache = NGX_CONF_UNSET;
     scf->session_timeout = NGX_CONF_UNSET;
+    scf->session_ticket_keys = NGX_CONF_UNSET_PTR;
 
     return scf;
 }
@@ -331,6 +339,15 @@ ngx_mail_ssl_merge_conf(ngx_conf_t *cf, void *parent, void *child)
         return NGX_CONF_ERROR;
     }
 
+    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;
+    }
+
     return NGX_CONF_OK;
 }
 
index 7f59b38ae39b2db7b00f040f68105387662f3f2a..54e057721945186e2c3b4735d009e38540218580 100644 (file)
@@ -41,6 +41,8 @@ typedef struct {
 
     ngx_shm_zone_t  *shm_zone;
 
+    ngx_array_t     *session_ticket_keys;
+
     u_char          *file;
     ngx_uint_t       line;
 } ngx_mail_ssl_conf_t;