1 files changed, 92 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/pubkey/xmss/xmss_signature.cpp b/comm/third_party/botan/src/lib/pubkey/xmss/xmss_signature.cpp
new file mode 100644
index 0000000000..98fadff358
--- /dev/null
+++ b/comm/third_party/botan/src/lib/pubkey/xmss/xmss_signature.cpp
@@ -0,0 +1,92 @@
+/*
+ * XMSS Signature
+ * (C) 2016,2017,2018 Matthias Gierlings
+ *
+ * Botan is released under the Simplified BSD License (see license.txt)
+ **/
+
+#include <botan/internal/xmss_signature.h>
+#include <iterator>
+
+namespace Botan {
+
+XMSS_Signature::XMSS_Signature(XMSS_Parameters::xmss_algorithm_t oid,
+                               const secure_vector<uint8_t>& raw_sig)
+   : m_leaf_idx(0), m_randomness(0, 0x00), m_tree_sig()
+   {
+   XMSS_Parameters xmss_params(oid);
+
+   if(raw_sig.size() != (xmss_params.len() + xmss_params.tree_height() + 1)
+                        * xmss_params.element_size() + sizeof(uint32_t))
+   {
+      throw Decoding_Error("XMSS signature size invalid.");
+   }
+
+   for(size_t i = 0; i < 4; i++)
+      { m_leaf_idx = ((m_leaf_idx << 8) | raw_sig[i]); }
+
+   if(m_leaf_idx >= (1ull << xmss_params.tree_height()))
+      {
+      throw Decoding_Error("XMSS signature leaf index out of bounds.");
+      }
+
+   auto begin = raw_sig.begin() + sizeof(uint32_t);
+   auto end = begin + xmss_params.element_size();
+   std::copy(begin, end, std::back_inserter(m_randomness));
+
+   for(size_t i = 0; i < xmss_params.len(); i++)
+      {
+      begin = end;
+      end = begin + xmss_params.element_size();
+      m_tree_sig.ots_signature().push_back(secure_vector<uint8_t>(0));
+      m_tree_sig.ots_signature().back().reserve(
+         xmss_params.element_size());
+      std::copy(begin,
+                end,
+                std::back_inserter(m_tree_sig.ots_signature().back()));
+      }
+
+   for(size_t i = 0; i < xmss_params.tree_height(); i++)
+      {
+      begin = end;
+      end = begin + xmss_params.element_size();
+      m_tree_sig.authentication_path().push_back(secure_vector<uint8_t>(0));
+      m_tree_sig.authentication_path().back().reserve(
+         xmss_params.element_size());
+      std::copy(begin,
+                end,
+                std::back_inserter(m_tree_sig.authentication_path().back()));
+      }
+   }
+
+secure_vector<uint8_t> XMSS_Signature::bytes() const
+   {
+   secure_vector<uint8_t> result
+      {
+      static_cast<uint8_t>(m_leaf_idx >> 24U),
+      static_cast<uint8_t>(m_leaf_idx >> 16U),
+      static_cast<uint8_t>(m_leaf_idx >>  8U),
+      static_cast<uint8_t>(m_leaf_idx)
+      };
+
+   std::copy(m_randomness.begin(),
+             m_randomness.end(),
+             std::back_inserter(result));
+
+   for(const auto& sig : tree().ots_signature())
+      {
+      std::copy(sig.begin(),
+                sig.end(),
+                std::back_inserter(result));
+      }
+
+   for(const auto& auth : tree().authentication_path())
+      {
+      std::copy(auth.begin(),
+                auth.end(),
+                std::back_inserter(result));
+      }
+   return result;
+   }
+
+}