1 files changed, 51 insertions, 0 deletions
diff --git a/src/kdf/kdf2/kdf2.cpp b/src/kdf/kdf2/kdf2.cpp
new file mode 100644
index 000000000..fa975ccb9
--- /dev/null
+++ b/src/kdf/kdf2/kdf2.cpp
@@ -0,0 +1,51 @@
+/*************************************************
+* KDF2 Source File                               *
+* (C) 1999-2007 Jack Lloyd                       *
+*************************************************/
+
+#include <botan/kdf2.h>
+#include <botan/lookup.h>
+#include <botan/loadstor.h>
+#include <memory>
+
+namespace Botan {
+
+/*************************************************
+* KDF2 Key Derivation Mechanism                  *
+*************************************************/
+SecureVector<byte> KDF2::derive(u32bit out_len,
+                                const byte secret[], u32bit secret_len,
+                                const byte P[], u32bit P_len) const
+   {
+   SecureVector<byte> output;
+   u32bit counter = 1;
+
+   std::auto_ptr<HashFunction> hash(get_hash(hash_name));
+   while(out_len && counter)
+      {
+      hash->update(secret, secret_len);
+      for(u32bit j = 0; j != 4; ++j)
+         hash->update(get_byte(j, counter));
+      hash->update(P, P_len);
+      SecureVector<byte> hash_result = hash->final();
+
+      u32bit added = std::min(hash_result.size(), out_len);
+      output.append(hash_result, added);
+      out_len -= added;
+
+      ++counter;
+      }
+
+   return output;
+   }
+
+/*************************************************
+* KDF2 Constructor                               *
+*************************************************/
+KDF2::KDF2(const std::string& h_name) : hash_name(h_name)
+   {
+   if(!have_hash(hash_name))
+      throw Algorithm_Not_Found(hash_name);
+   }
+
+}