Update comments

3 files changed, 9 insertions, 1 deletions

diff --git a/chacha.cpp b/chacha.cpp
index 321ebbaf..fcea81ec 100644
--- a/chacha.cpp
+++ b/chacha.cpp
@@ -316,6 +316,7 @@ std::string ChaCha_Policy::AlgorithmProvider() const
 void ChaCha_Policy::CipherSetKey(const NameValuePairs &params, const byte *key, size_t length)

 {

     CRYPTOPP_ASSERT(key); CRYPTOPP_ASSERT(length == 16 || length == 32);

+    CRYPTOPP_UNUSED(key); CRYPTOPP_UNUSED(length);

 

     m_rounds = params.GetIntValueWithDefault(Name::Rounds(), 20);

     if (m_rounds != 20 && m_rounds != 12 && m_rounds != 8)

@@ -337,7 +338,7 @@ void ChaCha_Policy::CipherSetKey(const NameValuePairs &params, const byte *key,
 void ChaCha_Policy::CipherResynchronize(byte *keystreamBuffer, const byte *IV, size_t length)

 {

     CRYPTOPP_UNUSED(keystreamBuffer), CRYPTOPP_UNUSED(length);

-    CRYPTOPP_ASSERT(length==8);

+    CRYPTOPP_ASSERT(length==8); CRYPTOPP_UNUSED(length);

 

     GetBlock<word32, LittleEndian> get(IV);

     m_state[12] = m_state[13] = 0;

diff --git a/chachapoly.cpp b/chachapoly.cpp
index 6d4d395e..8daff99d 100644
--- a/chachapoly.cpp
+++ b/chachapoly.cpp
@@ -8,6 +8,12 @@
 

 NAMESPACE_BEGIN(CryptoPP)

 

+// RekeyCipherAndMac is heavier-weight than we like. The Authenc framework was

+// predicated on BlcokCiphers, where the key and key schedule could be

+// calculated independent of the IV being used. However, the ChaCha and

+// ChaCha20Poly1305 construction cannot disgorge key setup and IV. Even a

+// simple Resync() forces us to regenerate the initial state for both

+// ChaCha20 and Poly1305.

 void ChaCha20Poly1305_Base::RekeyCipherAndMac(const byte *userKey, size_t keylength, const NameValuePairs &params)

 {

 	// Derive MAC key

diff --git a/chachapoly.h b/chachapoly.h
index 5f7e92e6..01637671 100644
--- a/chachapoly.h
+++ b/chachapoly.h
@@ -120,6 +120,7 @@ protected:
 };

 

 /// \brief ChaCha20Poly1305 cipher final implementation

+/// \tparam T_ForwardTransform flag indicating cipher direction

 /// \details ChaCha20Poly1305 is an authenticated encryption scheme that combines

 ///  ChaCha20TLS and Poly1305TLS. The scheme is defined in RFC 8439, section 2.8,

 ///  AEAD_CHACHA20_POLY1305 construction, and uses the IETF versions of ChaCha