From bec0a260e8ea978479895bb6d121686196ff03b2 Mon Sep 17 00:00:00 2001 From: Matt Corallo Date: Mon, 10 Feb 2020 18:32:57 -0500 Subject: [PATCH] Define a BLOCK_SIZE constant for chacha20 --- lightning/src/util/chacha20.rs | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/lightning/src/util/chacha20.rs b/lightning/src/util/chacha20.rs index 09e9a8475..8a8205f8d 100644 --- a/lightning/src/util/chacha20.rs +++ b/lightning/src/util/chacha20.rs @@ -56,6 +56,8 @@ mod real_chacha { } } + const BLOCK_SIZE: usize = 64; + #[derive(Clone,Copy)] struct ChaChaState { a: u32x4, @@ -67,7 +69,7 @@ mod real_chacha { #[derive(Copy)] pub struct ChaCha20 { state : ChaChaState, - output : [u8; 64], + output : [u8; BLOCK_SIZE], offset : usize, } @@ -135,7 +137,7 @@ mod real_chacha { assert!(key.len() == 16 || key.len() == 32); assert!(nonce.len() == 8 || nonce.len() == 12); - ChaCha20{ state: ChaCha20::expand(key, nonce), output: [0u8; 64], offset: 64 } + ChaCha20{ state: ChaCha20::expand(key, nonce), output: [0u8; BLOCK_SIZE], offset: 64 } } fn expand(key: &[u8], nonce: &[u8]) -> ChaChaState { @@ -197,7 +199,7 @@ mod real_chacha { } } - // put the the next 64 keystream bytes into self.output + // put the the next BLOCK_SIZE keystream bytes into self.output fn update(&mut self) { let mut state = self.state; @@ -234,12 +236,12 @@ mod real_chacha { while i < len { // If there is no keystream available in the output buffer, // generate the next block. - if self.offset == 64 { + if self.offset == BLOCK_SIZE { self.update(); } // Process the min(available keystream, remaining input length). - let count = cmp::min(64 - self.offset, len - i); + let count = cmp::min(BLOCK_SIZE - self.offset, len - i); // explicitly assert lengths to avoid bounds checks: assert!(output.len() >= i + count); assert!(input.len() >= i + count); @@ -258,12 +260,12 @@ mod real_chacha { while i < len { // If there is no keystream available in the output buffer, // generate the next block. - if self.offset == 64 { + if self.offset == BLOCK_SIZE { self.update(); } // Process the min(available keystream, remaining input length). - let count = cmp::min(64 - self.offset, len - i); + let count = cmp::min(BLOCK_SIZE - self.offset, len - i); // explicitly assert lengths to avoid bounds checks: assert!(input_output.len() >= i + count); assert!(self.output.len() >= self.offset + count); -- 2.39.5