Better tests for SIV

Correct errors in the AEAD tests that assumed process/update always
return something - that isn't true for SIV

Minor optimizations in CMAC and CTR to cache the block size instead
of making a zillion virtual calls for it.

Generalize SIV slightly to where it could support a non-128 bit
cipher, but don't pull the trigger on it since I can't find any
implementations to crosscheck with.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/lib/mac/cmac/cmac.h b/src/lib/mac/cmac/cmac.h
index 7c81272e8..9867c7d0e 100644
--- a/src/lib/mac/cmac/cmac.h
+++ b/src/lib/mac/cmac/cmac.h
@@ -20,7 +20,7 @@ class BOTAN_PUBLIC_API(2,0) CMAC final : public MessageAuthenticationCode
    {
    public:
       std::string name() const override;
-      size_t output_length() const override { return m_cipher->block_size(); }
+      size_t output_length() const override { return m_block_size; }
       MessageAuthenticationCode* clone() const override;
 
       void clear() override;
@@ -50,6 +50,7 @@ class BOTAN_PUBLIC_API(2,0) CMAC final : public MessageAuthenticationCode
 
       std::unique_ptr<BlockCipher> m_cipher;
       secure_vector<uint8_t> m_buffer, m_state, m_B, m_P;
+      const size_t m_block_size;
       size_t m_position;
    };