SSL: clear error queue after SSL_CTX_load_verify_locations().

The SSL_CTX_load_verify_locations() may leave errors in the error queue
while returning success (e.g. if there are duplicate certificates in the file
specified), resulting in "ignoring stale global SSL error" alerts later
at runtime.

diff --git a/src/event/ngx_event_openssl.c b/src/event/ngx_event_openssl.c
index 50746e7ac257eca79f454c524d849370a3d0f06e..f2419e46622b48ee1b37440c2b3a003e15120ba3 100644 (file)
--- a/src/event/ngx_event_openssl.c
+++ b/src/event/ngx_event_openssl.c
@@ -363,6 +363,13 @@ ngx_ssl_client_certificate(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *cert,
         return NGX_ERROR;
     }
 
+    /*
+     * SSL_CTX_load_verify_locations() may leave errors in the error queue
+     * while returning success
+     */
+
+    ERR_clear_error();
+
     list = SSL_load_client_CA_file((char *) cert->data);
 
     if (list == NULL) {
@@ -407,6 +414,13 @@ ngx_ssl_trusted_certificate(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *cert,
         return NGX_ERROR;
     }
 
+    /*
+     * SSL_CTX_load_verify_locations() may leave errors in the error queue
+     * while returning success
+     */
+
+    ERR_clear_error();
+
     return NGX_OK;
 }