upstream: Add experimental support for PQC XMSS keys (Extended

Hash-Based Signatures) The code is not compiled in by default (see WITH_XMSS
in Makefile.inc) Joint work with stefan-lukas_gazdag at genua.eu See
https://tools.ietf.org/html/draft-irtf-cfrg-xmss-hash-based-signatures-12 ok
djm@

OpenBSD-Commit-ID: ef3eccb96762a5d6f135d7daeef608df7776a7ac
diff --git a/xmss_hash_address.c b/xmss_hash_address.c
new file mode 100644
index 0000000..223c6f8
--- /dev/null
+++ b/xmss_hash_address.c
@@ -0,0 +1,59 @@
+/*
+hash_address.c version 20160722
+Andreas Hülsing
+Joost Rijneveld
+Public domain.
+*/
+#include <stdint.h>
+#include "xmss_hash_address.h"	/* prototypes */
+
+void setLayerADRS(uint32_t adrs[8], uint32_t layer){
+  adrs[0] = layer;
+}
+
+void setTreeADRS(uint32_t adrs[8], uint64_t tree){
+  adrs[1] = (uint32_t) (tree >> 32);
+  adrs[2] = (uint32_t) tree;
+}
+
+void setType(uint32_t adrs[8], uint32_t type){
+  adrs[3] = type;
+  int i;
+  for(i = 4; i < 8; i++){
+    adrs[i] = 0;
+  }
+}
+
+void setKeyAndMask(uint32_t adrs[8], uint32_t keyAndMask){
+  adrs[7] = keyAndMask;
+}
+
+// OTS
+
+void setOTSADRS(uint32_t adrs[8], uint32_t ots){
+  adrs[4] = ots;
+}
+
+void setChainADRS(uint32_t adrs[8], uint32_t chain){
+  adrs[5] = chain;
+}
+
+void setHashADRS(uint32_t adrs[8], uint32_t hash){
+  adrs[6] = hash;
+}
+
+// L-tree
+
+void setLtreeADRS(uint32_t adrs[8], uint32_t ltree){
+  adrs[4] = ltree;
+}
+
+// Hash Tree & L-tree
+
+void setTreeHeight(uint32_t adrs[8], uint32_t treeHeight){
+  adrs[5] = treeHeight;
+}
+
+void setTreeIndex(uint32_t adrs[8], uint32_t treeIndex){
+  adrs[6] = treeIndex;
+}