1 files changed, 137 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/pubkey/xmss/xmss_wots_parameters.cpp b/comm/third_party/botan/src/lib/pubkey/xmss/xmss_wots_parameters.cpp
new file mode 100644
index 0000000000..ef89c081c0
--- /dev/null
+++ b/comm/third_party/botan/src/lib/pubkey/xmss/xmss_wots_parameters.cpp
@@ -0,0 +1,137 @@
+/*
+ * XMSS WOTS Parameters
+ * Descibes a signature method for XMSS Winternitz One Time Signatures,
+ * as defined in:
+ * [1] XMSS: Extended Hash-Based Signatures,
+ *     Request for Comments: 8391
+ *     Release: May 2018.
+ *     https://datatracker.ietf.org/doc/rfc8391/
+ *
+ * (C) 2016,2017,2018 Matthias Gierlings
+ *
+ * Botan is released under the Simplified BSD License (see license.txt)
+ **/
+
+#include <botan/xmss_wots.h>
+#include <botan/internal/xmss_tools.h>
+#include <botan/exceptn.h>
+#include <cmath>
+
+namespace Botan {
+
+XMSS_WOTS_Parameters::ots_algorithm_t
+XMSS_WOTS_Parameters::xmss_wots_id_from_string(const std::string& param_set)
+   {
+   if(param_set == "WOTSP-SHA2_256")
+      { return WOTSP_SHA2_256; }
+   if(param_set == "WOTSP-SHA2_512")
+      { return WOTSP_SHA2_512; }
+   if(param_set == "WOTSP-SHAKE_256")
+      { return WOTSP_SHAKE_256; }
+   if(param_set == "WOTSP-SHAKE_512")
+      { return WOTSP_SHAKE_512; }
+   throw Invalid_Argument("Unknown XMSS-WOTS algorithm param '" + param_set + "'");
+   }
+
+XMSS_WOTS_Parameters::XMSS_WOTS_Parameters(const std::string& param_set)
+   : XMSS_WOTS_Parameters(xmss_wots_id_from_string(param_set))
+   {}
+
+XMSS_WOTS_Parameters::XMSS_WOTS_Parameters(ots_algorithm_t oid)
+   : m_oid(oid)
+   {
+   switch(oid)
+      {
+      case WOTSP_SHA2_256:
+         m_element_size = 32;
+         m_w = 16;
+         m_len = 67;
+         m_name = "WOTSP-SHA2_256";
+         m_hash_name = "SHA-256";
+         m_strength = 256;
+         break;
+      case WOTSP_SHA2_512:
+         m_element_size = 64;
+         m_w = 16;
+         m_len = 131;
+         m_name = "WOTSP-SHA2_512";
+         m_hash_name = "SHA-512";
+         m_strength = 512;
+         break;
+      case WOTSP_SHAKE_256:
+         m_element_size = 32;
+         m_w = 16;
+         m_len = 67;
+         m_name = "WOTSP-SHAKE_256";
+         m_hash_name = "SHAKE-128(256)";
+         m_strength = 256;
+         break;
+      case WOTSP_SHAKE_512:
+         m_element_size = 64;
+         m_w = 16;
+         m_len = 131;
+         m_name = "WOTSP-SHAKE_512";
+         m_hash_name = "SHAKE-256(512)";
+         m_strength = 512;
+         break;
+      default:
+         throw Not_Implemented("Algorithm id does not match any known XMSS WOTS algorithm id.");
+         break;
+      }
+
+   m_lg_w = (m_w == 16) ? 4 : 2;
+   m_len_1 = static_cast<size_t>(std::ceil((8 * element_size()) / m_lg_w));
+   m_len_2 = static_cast<size_t>(
+                floor(log2(m_len_1 * (wots_parameter() - 1)) / m_lg_w) + 1);
+   BOTAN_ASSERT(m_len == m_len_1 + m_len_2, "Invalid XMSS WOTS parameter "
+                "\"len\" detedted.");
+   }
+
+secure_vector<uint8_t>
+XMSS_WOTS_Parameters::base_w(const secure_vector<uint8_t>& msg, size_t out_size) const
+   {
+   secure_vector<uint8_t> result;
+   size_t in = 0;
+   size_t total = 0;
+   size_t bits = 0;
+
+   for(size_t i = 0; i < out_size; i++)
+      {
+      if(bits == 0)
+         {
+         total = msg[in];
+         in++;
+         bits += 8;
+         }
+      bits -= m_lg_w;
+      result.push_back(static_cast<uint8_t>((total >> bits) & (m_w - 1)));
+      }
+   return result;
+   }
+
+secure_vector<uint8_t>
+XMSS_WOTS_Parameters::base_w(size_t value) const
+   {
+   value <<= (8 - ((m_len_2 * m_lg_w) % 8));
+   size_t len_2_bytes = static_cast<size_t>(
+                           std::ceil(static_cast<float>(m_len_2 * m_lg_w) / 8.f));
+   secure_vector<uint8_t> result;
+   XMSS_Tools::concat(result, value, len_2_bytes);
+   return base_w(result, m_len_2);
+   }
+
+void
+XMSS_WOTS_Parameters::append_checksum(secure_vector<uint8_t>& data)
+   {
+   size_t csum = 0;
+
+   for(size_t i = 0; i < data.size(); i++)
+      {
+      csum += wots_parameter() - 1 - data[i];
+      }
+
+   secure_vector<uint8_t> csum_bytes = base_w(csum);
+   std::move(csum_bytes.begin(), csum_bytes.end(), std::back_inserter(data));
+   }
+
+}