Conditionally compile XMSS code.
The XMSS code is currently experimental and, unlike the rest of OpenSSH
cannot currently be compiled with a c89 compiler.
diff --git a/xmss_fast.h b/xmss_fast.h
index 657cd27..52a83f8 100644
--- a/xmss_fast.h
+++ b/xmss_fast.h
@@ -1,3 +1,4 @@
+#ifdef WITH_XMSS
/*
xmss_fast.h version 20160722
Andreas Hülsing
@@ -106,4 +107,4 @@
*/
int xmssmt_sign_open(unsigned char *msg, unsigned long long *msglen, const unsigned char *sig_msg, unsigned long long sig_msg_len, const unsigned char *pk, const xmssmt_params *params);
#endif
-
+#endif /* WITH_XMSS */