OpenBSD 5.4 errata 15, Oct 1, 2014: Fix for the SSL session reuse
vulnerability (CVE-2014-3616).
Apply patch using:
cat 015_nginx.patch | (cd /usr/src && patch -p0)
Then build and install nginx:
cd /usr/src/usr.sbin/nginx
make -f Makefile.bsd-wrapper obj
make -f Makefile.bsd-wrapper
make -f Makefile.bsd-wrapper install
Index: usr.sbin/nginx/src/event/ngx_event_openssl.c
===================================================================
RCS file: /cvs/src/usr.sbin/nginx/src/event/ngx_event_openssl.c,v
retrieving revision 1.12
diff -u -p -u -r1.12 ngx_event_openssl.c
--- usr.sbin/nginx/src/event/ngx_event_openssl.c 1 Jun 2013 16:12:54 -0000 1.12
+++ usr.sbin/nginx/src/event/ngx_event_openssl.c 18 Sep 2014 14:18:24 -0000
@@ -27,6 +27,8 @@ static void ngx_ssl_connection_error(ngx
ngx_err_t err, char *text);
static void ngx_ssl_clear_error(ngx_log_t *log);
+static ngx_int_t ngx_ssl_session_id_context(ngx_ssl_t *ssl,
+ ngx_str_t *sess_ctx);
ngx_int_t ngx_ssl_session_cache_init(ngx_shm_zone_t *shm_zone, void *data);
static int ngx_ssl_new_session(ngx_ssl_conn_t *ssl_conn,
ngx_ssl_session_t *sess);
@@ -1659,13 +1661,15 @@ ngx_ssl_session_cache(ngx_ssl_t *ssl, ng
{
long cache_mode;
+ if (ngx_ssl_session_id_context(ssl, sess_ctx) != NGX_OK) {
+ return NGX_ERROR;
+ }
+
if (builtin_session_cache == NGX_SSL_NO_SCACHE) {
SSL_CTX_set_session_cache_mode(ssl->ctx, SSL_SESS_CACHE_OFF);
return NGX_OK;
}
- SSL_CTX_set_session_id_context(ssl->ctx, sess_ctx->data, sess_ctx->len);
-
if (builtin_session_cache == NGX_SSL_NONE_SCACHE) {
/*
@@ -1769,6 +1773,94 @@ ngx_ssl_session_cache_init(ngx_shm_zone_
return NGX_OK;
}
+static ngx_int_t
+ngx_ssl_session_id_context(ngx_ssl_t *ssl, ngx_str_t *sess_ctx)
+{
+ int n, i;
+ X509 *cert;
+ X509_NAME *name;
+ EVP_MD_CTX md;
+ unsigned int len;
+ STACK_OF(X509_NAME) *list;
+ u_char buf[EVP_MAX_MD_SIZE];
+
+ /*
+ * Session ID context is set based on the string provided,
+ * the server certificate, and the client CA list.
+ */
+
+ EVP_MD_CTX_init(&md);
+
+ if (EVP_DigestInit_ex(&md, EVP_sha1(), NULL) == 0) {
+ ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
+ "EVP_DigestInit_ex() failed");
+ goto failed;
+ }
+
+ if (EVP_DigestUpdate(&md, sess_ctx->data, sess_ctx->len) == 0) {
+ ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
+ "EVP_DigestUpdate() failed");
+ goto failed;
+ }
+
+ cert = SSL_CTX_get_ex_data(ssl->ctx, ngx_ssl_certificate_index);
+
+ if (X509_digest(cert, EVP_sha1(), buf, &len) == 0) {
+ ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
+ "X509_digest() failed");
+ goto failed;
+ }
+
+ if (EVP_DigestUpdate(&md, buf, len) == 0) {
+ ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
+ "EVP_DigestUpdate() failed");
+ goto failed;
+ }
+
+ list = SSL_CTX_get_client_CA_list(ssl->ctx);
+
+ if (list != NULL) {
+ n = sk_X509_NAME_num(list);
+
+ for (i = 0; i < n; i++) {
+ name = sk_X509_NAME_value(list, i);
+
+ if (X509_NAME_digest(name, EVP_sha1(), buf, &len) == 0) {
+ ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
+ "X509_NAME_digest() failed");
+ goto failed;
+ }
+
+ if (EVP_DigestUpdate(&md, buf, len) == 0) {
+ ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
+ "EVP_DigestUpdate() failed");
+ goto failed;
+ }
+ }
+ }
+
+ if (EVP_DigestFinal_ex(&md, buf, &len) == 0) {
+ ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
+ "EVP_DigestUpdate() failed");
+ goto failed;
+ }
+
+ EVP_MD_CTX_cleanup(&md);
+
+ if (SSL_CTX_set_session_id_context(ssl->ctx, buf, len) == 0) {
+ ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
+ "SSL_CTX_set_session_id_context() failed");
+ return NGX_ERROR;
+ }
+
+ return NGX_OK;
+
+failed:
+
+ EVP_MD_CTX_cleanup(&md);
+
+ return NGX_ERROR;
+}
/*
* The length of the session id is 16 bytes for SSLv2 sessions and
