Adding StreamCipher::seek interface, supporting seek in ChaCha, and also adding ChaCha8 support

2 files changed, 6 insertions, 0 deletions

diff --git a/src/lib/stream/ctr/ctr.cpp b/src/lib/stream/ctr/ctr.cpp
index f5301c099..43609ba2d 100644
--- a/src/lib/stream/ctr/ctr.cpp
+++ b/src/lib/stream/ctr/ctr.cpp
@@ -125,4 +125,8 @@ void CTR_BE::increment_counter()
    m_pad_pos = 0;
    }
 
+void CTR_BE::seek(u64bit)
+   {
+   throw Not_Implemented("CTR_BE::seek");
+   }
 }
diff --git a/src/lib/stream/ctr/ctr.h b/src/lib/stream/ctr/ctr.h
index 003297b92..5d5556254 100644
--- a/src/lib/stream/ctr/ctr.h
+++ b/src/lib/stream/ctr/ctr.h
@@ -46,6 +46,8 @@ class BOTAN_DLL CTR_BE final : public StreamCipher
       explicit CTR_BE(BlockCipher* cipher);
 
       CTR_BE(BlockCipher* cipher, size_t ctr_size);
+
+      void seek(u64bit offset) override;
    private:
       void key_schedule(const byte key[], size_t key_len) override;
       void increment_counter();