1 files changed, 49 insertions, 0 deletions
diff --git a/src/stream/ctr/ctr.h b/src/stream/ctr/ctr.h
new file mode 100644
index 000000000..f60f21b5a
--- /dev/null
+++ b/src/stream/ctr/ctr.h
@@ -0,0 +1,49 @@
+/*
+* CTR-BE Mode
+* (C) 1999-2007 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_CTR_BE_H__
+#define BOTAN_CTR_BE_H__
+
+#include <botan/block_cipher.h>
+#include <botan/stream_cipher.h>
+
+namespace Botan {
+
+/*
+* CTR-BE (Counter, big-endian)
+*/
+class BOTAN_DLL CTR_BE : public StreamCipher
+   {
+   public:
+      void cipher(const byte in[], byte out[], u32bit length);
+
+      void set_iv(const byte iv[], u32bit iv_len);
+
+      bool valid_iv_length(u32bit iv_len) const
+         { return (iv_len <= permutation->BLOCK_SIZE); }
+
+      std::string name() const;
+
+      CTR_BE* clone() const
+         { return new CTR_BE(permutation->clone()); }
+
+      void clear() throw();
+
+      CTR_BE(BlockCipher*);
+      ~CTR_BE();
+   private:
+      void key_schedule(const byte key[], u32bit key_len);
+      void increment_counter();
+
+      BlockCipher* permutation;
+      SecureVector<byte> counter, buffer;
+      u32bit position;
+   };
+
+}
+
+#endif