Add HashFunction::copy_state

See GH #1037

2 files changed, 13 insertions, 0 deletions

diff --git a/src/lib/hash/par_hash/par_hash.cpp b/src/lib/hash/par_hash/par_hash.cpp
index 2a1ef7c9c..af43d6d97 100644
--- a/src/lib/hash/par_hash/par_hash.cpp
+++ b/src/lib/hash/par_hash/par_hash.cpp
@@ -56,6 +56,18 @@ HashFunction* Parallel::clone() const
    return new Parallel(hash_copies);
    }
 
+std::unique_ptr<HashFunction> Parallel::copy_state() const
+   {
+   std::vector<std::unique_ptr<HashFunction>> hash_clones;
+
+   for(const std::unique_ptr<HashFunction>& hash : m_hashes)
+      {
+      hash_clones.push_back(hash->copy_state());
+      }
+
+   return std::unique_ptr<HashFunction>(new Parallel(hash_clones));
+   }
+
 void Parallel::clear()
    {
    for(auto&& hash : m_hashes)
diff --git a/src/lib/hash/par_hash/par_hash.h b/src/lib/hash/par_hash/par_hash.h
index cf6f49af4..85bf49208 100644
--- a/src/lib/hash/par_hash/par_hash.h
+++ b/src/lib/hash/par_hash/par_hash.h
@@ -22,6 +22,7 @@ class BOTAN_DLL Parallel final : public HashFunction
       void clear() override;
       std::string name() const override;
       HashFunction* clone() const override;
+      std::unique_ptr<HashFunction> copy_state() const override;
 
       size_t output_length() const override;