Implements changes from XMSS review

- Removes custom XMSS_Hash assignment operator.
- Changes mutex type used in XMSS_Index_Registryfrom std::mutex to
  Botan::mutex_type, changes lock_guard accordingly.
- Removes singleton and endianess detection from XMSS_Tools, changes
  XMSS_Tools::concat() to be a static method.
- XMSS/XMSS_WOTS check_key() now always returns true.

13 files changed, 18 insertions, 82 deletions

diff --git a/src/lib/pubkey/xmss/info.txt b/src/lib/pubkey/xmss/info.txt
index a92b06beb..bab541625 100644
--- a/src/lib/pubkey/xmss/info.txt
+++ b/src/lib/pubkey/xmss/info.txt
@@ -9,7 +9,6 @@ xmss_privatekey.cpp
 xmss_publickey.cpp
 xmss_signature.cpp
 xmss_signature_operation.cpp
-xmss_tools.cpp
 xmss_verification_operation.cpp
 xmss_wots_parameters.cpp
 xmss_wots_privatekey.cpp
diff --git a/src/lib/pubkey/xmss/xmss_hash.cpp b/src/lib/pubkey/xmss/xmss_hash.cpp
index 15cdab509..2dfcabbbc 100644
--- a/src/lib/pubkey/xmss/xmss_hash.cpp
+++ b/src/lib/pubkey/xmss/xmss_hash.cpp
@@ -76,13 +76,4 @@ XMSS_Hash::h_msg(const secure_vector<byte>& randomness,
    return m_msg_hash->final();
    }
 
-XMSS_Hash& XMSS_Hash::operator=(XMSS_Hash hash)
-   {
-   std::swap(m_hash, hash.m_hash);
-   std::swap(m_msg_hash, hash.m_msg_hash);
-   std::swap(m_output_length, hash.m_output_length);
-   std::swap(m_zero_padding, hash.m_zero_padding);
-   return *this;
-   }
-
 }
diff --git a/src/lib/pubkey/xmss/xmss_hash.h b/src/lib/pubkey/xmss/xmss_hash.h
index da059fb7b..1af9feb25 100644
--- a/src/lib/pubkey/xmss/xmss_hash.h
+++ b/src/lib/pubkey/xmss/xmss_hash.h
@@ -26,7 +26,6 @@ class XMSS_Hash
    public:
       XMSS_Hash(const std::string& h_func_name);
       XMSS_Hash(const XMSS_Hash& hash);
-      XMSS_Hash& operator=(XMSS_Hash hash);
 
       /**
        * Pseudoranom function creating a hash out of a key and data using
diff --git a/src/lib/pubkey/xmss/xmss_index_registry.cpp b/src/lib/pubkey/xmss/xmss_index_registry.cpp
index f7f4ec470..a85bc7c9f 100644
--- a/src/lib/pubkey/xmss/xmss_index_registry.cpp
+++ b/src/lib/pubkey/xmss/xmss_index_registry.cpp
@@ -63,7 +63,7 @@ size_t XMSS_Index_Registry::get(uint64_t id) const
 
 size_t XMSS_Index_Registry::add(uint64_t id, size_t last_unused)
    {
-   std::lock_guard<std::mutex> lock(m_mutex);
+   lock_guard_type<mutex_type> lock(m_mutex);
    size_t pos = get(id);
    if(pos < m_key_ids.size())
       {
diff --git a/src/lib/pubkey/xmss/xmss_index_registry.h b/src/lib/pubkey/xmss/xmss_index_registry.h
index 5dcb6d31b..8759ca03b 100644
--- a/src/lib/pubkey/xmss/xmss_index_registry.h
+++ b/src/lib/pubkey/xmss/xmss_index_registry.h
@@ -12,12 +12,12 @@
 #include <cstddef>
 #include <limits>
 #include <memory>
-#include <mutex>
 #include <string>
 #include <botan/hash.h>
 #include <botan/secmem.h>
 #include <botan/types.h>
 #include <botan/atomic.h>
+#include <botan/mutex.h>
 
 namespace Botan {
 
@@ -101,7 +101,7 @@ class XMSS_Index_Registry
 
       std::vector<uint64_t> m_key_ids;
       std::vector<std::shared_ptr<Atomic<size_t>>> m_leaf_indices;
-      std::mutex m_mutex;
+      mutex_type m_mutex;
    };
 
 }
diff --git a/src/lib/pubkey/xmss/xmss_publickey.h b/src/lib/pubkey/xmss/xmss_publickey.h
index faa35d80a..a18c70836 100644
--- a/src/lib/pubkey/xmss/xmss_publickey.h
+++ b/src/lib/pubkey/xmss/xmss_publickey.h
@@ -198,7 +198,7 @@ class BOTAN_DLL XMSS_PublicKey : public virtual Public_Key
 
       virtual bool check_key(RandomNumberGenerator&, bool) const override
          {
-         BOTAN_ASSERT(false, "No key strength check implemented for XMSS.");
+         return true;
          }
 
       virtual std::unique_ptr<PK_Ops::Verification>
@@ -212,17 +212,7 @@ class BOTAN_DLL XMSS_PublicKey : public virtual Public_Key
 
       virtual size_t max_input_bits() const override
          {
-         return std::numeric_limits<size_t>::infinity();
-         }
-
-      virtual size_t message_part_size() const override
-         {
-         return std::numeric_limits<size_t>::infinity();
-         }
-
-      virtual size_t message_parts() const override
-         {
-         return std::numeric_limits<size_t>::infinity();
+         throw Not_Implemented("XMSS doesn't support max_input_bits().");
          }
 
       /**
diff --git a/src/lib/pubkey/xmss/xmss_signature_operation.cpp b/src/lib/pubkey/xmss/xmss_signature_operation.cpp
index d223ddef0..07121db14 100644
--- a/src/lib/pubkey/xmss/xmss_signature_operation.cpp
+++ b/src/lib/pubkey/xmss/xmss_signature_operation.cpp
@@ -97,10 +97,10 @@ void XMSS_Signature_Operation::initialize()
    m_leaf_idx = m_priv_key.reserve_unused_leaf_index();
 
    // write prefix for message hashing into buffer.
-   XMSS_Tools::get().concat(index_bytes, m_leaf_idx, 32);
+   XMSS_Tools::concat(index_bytes, m_leaf_idx, 32);
    m_randomness = m_hash.prf(m_priv_key.prf(), index_bytes);
    index_bytes.clear();
-   XMSS_Tools::get().concat(index_bytes, m_leaf_idx,
+   XMSS_Tools::concat(index_bytes, m_leaf_idx,
                             m_priv_key.xmss_parameters().element_size());
    m_hash.h_msg_init(m_randomness,
                      m_priv_key.root(),
diff --git a/src/lib/pubkey/xmss/xmss_tools.cpp b/src/lib/pubkey/xmss/xmss_tools.cpp
deleted file mode 100644
index 13e66759c..000000000
--- a/src/lib/pubkey/xmss/xmss_tools.cpp
+++ /dev/null
@@ -1,32 +0,0 @@
-/**
- * XMSS Tools
- * Contains some helper functions.
- * (C) 2016 Matthias Gierlings
- *
- * Botan is released under the Simplified BSD License (see license.txt)
- **/
-#include <botan/xmss_tools.h>
-
-namespace Botan {
-
-XMSS_Tools::XMSS_Tools()
-   {
-#if defined(BOTAN_TARGET_CPU_HAS_KNOWN_ENDIANESS)
-#if defined(BOTAN_TARGET_CPU_IS_LITTLE_ENDIAN)
-           m_is_little_endian = true;
-#else
-           m_is_little_endian = false;
-#endif
-#else
-       uint16_t data = 0x01;
-       m_is_little_endian = reinterpret_cast<const byte*>(&data)[0] == 0x01;
-#endif
-   }
-
-const XMSS_Tools& XMSS_Tools::get()
-   {
-   static const XMSS_Tools self;
-   return self;
-   }
-
-}
diff --git a/src/lib/pubkey/xmss/xmss_tools.h b/src/lib/pubkey/xmss/xmss_tools.h
index 07e36ea71..773953fae 100644
--- a/src/lib/pubkey/xmss/xmss_tools.h
+++ b/src/lib/pubkey/xmss/xmss_tools.h
@@ -11,6 +11,7 @@
 #include <stdint.h>
 #include <iterator>
 #include <type_traits>
+#include <botan/cpuid.h>
 #include <botan/types.h>
 #include <botan/secmem.h>
 
@@ -26,16 +27,6 @@ namespace Botan {
       XMSS_Tools(const XMSS_Tools&) = delete;
       void operator=(const XMSS_Tools&) = delete;
 
-      static const XMSS_Tools& get();
-
-      /**
-       * Retrieves information about endianess
-       *
-       * @return true if machine uses little-endian byte order, false
-       *         otherwise.
-       **/
-      inline bool is_little_endian() const { return m_is_little_endian; }
-
       /**
        * Concatenates the byte representation in big-endian order of any
        * integral value to a secure_vector.
@@ -47,7 +38,7 @@ namespace Botan {
       template<typename T,
                typename U = typename std::enable_if<std::is_integral<T>::value,
                                                     void>::type>
-      void concat(secure_vector<byte>& target, const T& src) const;
+      static void concat(secure_vector<byte>& target, const T& src);
 
       /**
        * Concatenates the last n bytes of the byte representation in big-endian
@@ -62,19 +53,17 @@ namespace Botan {
       template <typename T,
                 typename U = typename std::enable_if<std::is_integral<T>::value,
                 void>::type>
-      void concat(secure_vector<byte>& target, const T& src, size_t len) const;
+      static void concat(secure_vector<byte>& target, const T& src, size_t len);
 
    private:
       XMSS_Tools();
-
-      bool m_is_little_endian;
    };
 
 template <typename T, typename U>
-void XMSS_Tools::concat(secure_vector<byte>& target, const T& src) const
+void XMSS_Tools::concat(secure_vector<byte>& target, const T& src)
    {
    const byte* src_bytes = reinterpret_cast<const byte*>(&src);
-   if(is_little_endian())
+   if(CPUID::is_little_endian())
       std::reverse_copy(src_bytes,
                         src_bytes + sizeof(src),
                         std::back_inserter(target));
@@ -88,7 +77,7 @@ void XMSS_Tools::concat(secure_vector<byte>& target, const T& src) const
 template <typename T, typename U>
 void XMSS_Tools::concat(secure_vector<byte>& target,
                         const T& src,
-                        size_t len) const
+                        size_t len)
    {
    size_t c = static_cast<size_t>(std::min(len, sizeof(src)));
    if(len > sizeof(src))
@@ -97,7 +86,7 @@ void XMSS_Tools::concat(secure_vector<byte>& target,
       }
 
    const byte* src_bytes = reinterpret_cast<const byte*>(&src);
-   if(is_little_endian())
+   if(CPUID::is_little_endian())
       std::reverse_copy(src_bytes,
                         src_bytes + c,
                         std::back_inserter(target));
diff --git a/src/lib/pubkey/xmss/xmss_verification_operation.cpp b/src/lib/pubkey/xmss/xmss_verification_operation.cpp
index 20945e8ca..79bd61d17 100644
--- a/src/lib/pubkey/xmss/xmss_verification_operation.cpp
+++ b/src/lib/pubkey/xmss/xmss_verification_operation.cpp
@@ -77,7 +77,7 @@ XMSS_Verification_Operation::verify(const XMSS_Signature& sig,
    {
    XMSS_Address adrs;
    secure_vector<byte> index_bytes;
-   XMSS_Tools::get().concat(index_bytes,
+   XMSS_Tools::concat(index_bytes,
                             sig.unused_leaf_index(),
                             m_xmss_params.element_size());
    secure_vector<byte> msg_digest =
diff --git a/src/lib/pubkey/xmss/xmss_wots_parameters.cpp b/src/lib/pubkey/xmss/xmss_wots_parameters.cpp
index b908afeb4..903885d72 100644
--- a/src/lib/pubkey/xmss/xmss_wots_parameters.cpp
+++ b/src/lib/pubkey/xmss/xmss_wots_parameters.cpp
@@ -109,7 +109,7 @@ XMSS_WOTS_Parameters::base_w(size_t value) const
    size_t len_2_bytes = static_cast<size_t>(
       ceil(static_cast<float>(m_len_2 * m_lg_w) / 8.f));
    secure_vector<byte> result;
-   XMSS_Tools::get().concat(result, value, len_2_bytes);
+   XMSS_Tools::concat(result, value, len_2_bytes);
    return base_w(result, m_len_2);
    }
 
diff --git a/src/lib/pubkey/xmss/xmss_wots_privatekey.cpp b/src/lib/pubkey/xmss/xmss_wots_privatekey.cpp
index f94ba3612..1a68b187d 100644
--- a/src/lib/pubkey/xmss/xmss_wots_privatekey.cpp
+++ b/src/lib/pubkey/xmss/xmss_wots_privatekey.cpp
@@ -20,7 +20,7 @@ XMSS_WOTS_PrivateKey::generate(const secure_vector<byte>& priv_seed)
 
    for(size_t i = 0; i < m_wots_params.len(); i++)
       {
-      XMSS_Tools::get().concat<size_t>(priv_key[i], i, 32);
+      XMSS_Tools::concat<size_t>(priv_key[i], i, 32);
       m_hash.prf(priv_key[i], priv_seed, priv_key[i]);
       }
    return priv_key;
diff --git a/src/lib/pubkey/xmss/xmss_wots_privatekey.h b/src/lib/pubkey/xmss/xmss_wots_privatekey.h
index 422d014f4..2c38faad6 100644
--- a/src/lib/pubkey/xmss/xmss_wots_privatekey.h
+++ b/src/lib/pubkey/xmss/xmss_wots_privatekey.h
@@ -118,7 +118,7 @@ class BOTAN_DLL XMSS_WOTS_PrivateKey : public virtual XMSS_WOTS_PublicKey,
       wots_keysig_t operator[](size_t i)
          {
          secure_vector<byte> idx_bytes;
-         XMSS_Tools::get().concat(idx_bytes, i, m_wots_params.element_size());
+         XMSS_Tools::concat(idx_bytes, i, m_wots_params.element_size());
          m_hash.h(idx_bytes, m_private_seed, idx_bytes);
          return generate(idx_bytes);
          }