From 779e28a9b0ced5eb7a16c79a318501d5f04e6a13 Mon Sep 17 00:00:00 2001 From: Jeffrey Walton Date: Fri, 25 Jan 2019 19:04:34 -0500 Subject: [PATCH] Update comments --- chacha.cpp | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/chacha.cpp b/chacha.cpp index 3676eaf7..2514aeb1 100644 --- a/chacha.cpp +++ b/chacha.cpp @@ -79,10 +79,11 @@ typedef word32 WordType; enum {BYTES_PER_ITERATION=64}; // MultiBlockSafe detects a condition that can arise in the SIMD -// implementations where we overflow one of the 32-bit state words -// during addition in an intermediate result. Conditions to trigger -// issue include a user seeks to around 2^32 blocks (256 GB of data). -// https://github.com/weidai11/cryptopp/issues/732 +// implementations where we overflow one of the 32-bit state words during +// addition in an intermediate result. Preconditions for the issue include +// a user seeks to around 2^32 blocks (256 GB of data) for ChaCha; or a +// user specifies an arbitrarily large initial counter block for ChaChaTLS. +// Also see https://github.com/weidai11/cryptopp/issues/732. inline bool MultiBlockSafe(unsigned int ctrLow, unsigned int blocks) { return 0xffffffff - ctrLow > blocks;