openssl: Ensure the thread ID is never zero

This might otherwise cause problems because OpenSSL tries to lock
mutexes recursively if it assumes the lock is held by a different
thread e.g. during FIPS initialization.

diff --git a/src/libstrongswan/plugins/openssl/openssl_plugin.c b/src/libstrongswan/plugins/openssl/openssl_plugin.c
index 5a114122a17648072384a3ab3460362de22fbfe5..7daa92bef5f01d9936d430bc274fec09f40463c7 100644 (file)
--- a/src/libstrongswan/plugins/openssl/openssl_plugin.c
+++ b/src/libstrongswan/plugins/openssl/openssl_plugin.c
@@ -129,7 +129,9 @@ static void destroy_function(struct CRYPTO_dynlock_value *lock,
  */
 static unsigned long id_function(void)
 {
-       return (unsigned long)thread_current_id();
+       /* ensure the thread ID is never zero, otherwise OpenSSL might try to
+        * acquire locks recursively */
+       return 1 + (unsigned long)thread_current_id();
 }
 
 /**