[nginx] SSL: avoid SSL_CTX_set_tmp_rsa_callback() call with Libr...

[Maxim Dounin]

details:   http://hg.nginx.org/nginx/rev/a84267233877
branches:  
changeset: 6035:a84267233877
user:      Maxim Dounin <mdounin at mdounin.ru>
date:      Mon Mar 23 02:42:34 2015 +0300
description:
SSL: avoid SSL_CTX_set_tmp_rsa_callback() call with LibreSSL.

LibreSSL removed support for export ciphers and a call to
SSL_CTX_set_tmp_rsa_callback() results in an error left in the error
queue.  This caused alerts "ignoring stale global SSL error (...called
a function you should not call) while SSL handshaking" on a first connection
in each worker process.

diffstat:

 src/http/modules/ngx_http_ssl_module.c |  2 ++
 src/mail/ngx_mail_ssl_module.c         |  2 ++
 2 files changed, 4 insertions(+), 0 deletions(-)

diffs (27 lines):

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
@@ -715,8 +715,10 @@ ngx_http_ssl_merge_srv_conf(ngx_conf_t *
         SSL_CTX_set_options(conf->ssl.ctx, SSL_OP_CIPHER_SERVER_PREFERENCE);
     }
 
+#ifndef LIBRESSL_VERSION_NUMBER
     /* a temporary 512-bit RSA key is required for export versions of MSIE */
     SSL_CTX_set_tmp_rsa_callback(conf->ssl.ctx, ngx_ssl_rsa512_key_callback);
+#endif
 
     if (ngx_ssl_dhparam(cf, &conf->ssl, &conf->dhparam) != NGX_OK) {
         return NGX_CONF_ERROR;
diff --git a/src/mail/ngx_mail_ssl_module.c b/src/mail/ngx_mail_ssl_module.c
--- a/src/mail/ngx_mail_ssl_module.c
+++ b/src/mail/ngx_mail_ssl_module.c
@@ -421,7 +421,9 @@ ngx_mail_ssl_merge_conf(ngx_conf_t *cf, 
         SSL_CTX_set_options(conf->ssl.ctx, SSL_OP_CIPHER_SERVER_PREFERENCE);
     }
 
+#ifndef LIBRESSL_VERSION_NUMBER
     SSL_CTX_set_tmp_rsa_callback(conf->ssl.ctx, ngx_ssl_rsa512_key_callback);
+#endif
 
     if (ngx_ssl_dhparam(cf, &conf->ssl, &conf->dhparam) != NGX_OK) {
         return NGX_CONF_ERROR;