details: http://hg.nginx.org/nginx/rev/1356a3b96924
branches:
changeset: 5425:1356a3b96924
user: Piotr Sikora <piotr@cloudflare.com>
date: Fri Oct 11 16:05:24 2013 -0700
description:
SSL: added ability to set keys used for Session Tickets (RFC5077).

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>

diffstat:

src/event/ngx_event_openssl.c | 227 +++++++++++++++++++++++++++++++++
src/event/ngx_event_openssl.h | 13 +
src/http/modules/ngx_http_ssl_module.c | 17 ++
src/http/modules/ngx_http_ssl_module.h | 2 +
src/mail/ngx_mail_ssl_module.c | 17 ++
src/mail/ngx_mail_ssl_module.h | 2 +
6 files changed, 278 insertions(+), 0 deletions(-)

diffs (truncated from 401 to 300 lines):

diff --git a/src/event/ngx_event_openssl.c b/src/event/ngx_event_openssl.c
--- a/src/event/ngx_event_openssl.c
+++ b/src/event/ngx_event_openssl.c
@@ -38,6 +38,12 @@ static void ngx_ssl_expire_sessions(ngx_
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_
}


+#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)
{
diff --git a/src/event/ngx_event_openssl.h b/src/event/ngx_event_openssl.h
--- a/src/event/ngx_event_openssl.h
+++ b/src/event/ngx_event_openssl.h
@@ -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_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;

diff --git a/src/http/modules/ngx_http_ssl_module.c b/src/http/modules/ngx_http_ssl_module.c
--- a/src/http/modules/ngx_http_ssl_module.c
+++ b/src/http/modules/ngx_http_ssl_module.c
@@ -153,6 +153,13 @@ static ngx_command_t ngx_http_ssl_comma
0,

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