X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Futil%2Fchacha20.rs;h=c23856b60c8d69fb412e04f2eb3934b8ac29ff35;hb=0d75a63ead0601ae36e7141834f67c881c31eb85;hp=dd90b20f694587f754e1f6e7fe16ecc13db4892d;hpb=88fef649b15fa030cb91de76d58346a0bc408834;p=rust-lightning

diff --git a/lightning/src/util/chacha20.rs b/lightning/src/util/chacha20.rs
index dd90b20f..c23856b6 100644
--- a/lightning/src/util/chacha20.rs
+++ b/lightning/src/util/chacha20.rs
@@ -2,12 +2,14 @@
 // Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
+//
+// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
+// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
+// You may not use this file except in accordance with one or both of these
+// licenses.
 
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
+use std::io;
 
 #[cfg(not(feature = "fuzztarget"))]
 mod real_chacha {
@@ -54,6 +56,8 @@ mod real_chacha {
 		}
 	}
 
+	const BLOCK_SIZE: usize = 64;
+
 	#[derive(Clone,Copy)]
 	struct ChaChaState {
 		a: u32x4,
@@ -65,7 +69,7 @@ mod real_chacha {
 	#[derive(Copy)]
 	pub struct ChaCha20 {
 		state  : ChaChaState,
-		output : [u8; 64],
+		output : [u8; BLOCK_SIZE],
 		offset : usize,
 	}
 
@@ -133,7 +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 {
@@ -195,7 +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;
 
@@ -224,6 +228,7 @@ mod real_chacha {
 			self.offset = 0;
 		}
 
+		#[inline] // Useful cause input may be 0s on stack that should be optimized out
 		pub fn process(&mut self, input: &[u8], output: &mut [u8]) {
 			assert!(input.len() == output.len());
 			let len = input.len();
@@ -231,12 +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);
@@ -248,6 +253,29 @@ mod real_chacha {
 				self.offset += count;
 			}
 		}
+
+		pub fn process_in_place(&mut self, input_output: &mut [u8]) {
+			let len = input_output.len();
+			let mut i = 0;
+			while i < len {
+				// If there is no keystream available in the output buffer,
+				// generate the next block.
+				if self.offset == BLOCK_SIZE {
+					self.update();
+				}
+
+				// Process the min(available keystream, remaining input length).
+				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);
+				for j in 0..count {
+					input_output[i + j] ^= self.output[self.offset + j];
+				}
+				i += count;
+				self.offset += count;
+			}
+		}
 	}
 }
 #[cfg(not(feature = "fuzztarget"))]
@@ -267,11 +295,27 @@ mod fuzzy_chacha {
 		pub fn process(&mut self, input: &[u8], output: &mut [u8]) {
 			output.copy_from_slice(input);
 		}
+
+		pub fn process_in_place(&mut self, _input_output: &mut [u8]) {}
 	}
 }
 #[cfg(feature = "fuzztarget")]
 pub use self::fuzzy_chacha::ChaCha20;
 
+pub(crate) struct ChaChaReader<'a, R: io::Read> {
+	pub chacha: &'a mut ChaCha20,
+	pub read: R,
+}
+impl<'a, R: io::Read> io::Read for ChaChaReader<'a, R> {
+	fn read(&mut self, dest: &mut [u8]) -> Result<usize, io::Error> {
+		let res = self.read.read(dest)?;
+		if res > 0 {
+			self.chacha.process_in_place(&mut dest[0..res]);
+		}
+		Ok(res)
+	}
+}
+
 #[cfg(test)]
 mod test {
 	use std::iter::repeat;
@@ -284,7 +328,7 @@ mod test {
 			key:   [u8; 32],
 			nonce: [u8; 8],
 			keystream: Vec<u8>,
-		};
+		}
 		// taken from http://tools.ietf.org/html/draft-agl-tls-chacha20poly1305-04
 		let test_vectors = vec!(
 			TestVector{
@@ -419,7 +463,7 @@ mod test {
 			key:   [u8; 32],
 			nonce: [u8; 12],
 			keystream: Vec<u8>,
-		};
+		}
 		// taken from http://tools.ietf.org/html/draft-agl-tls-chacha20poly1305-04
 		let test_vectors = vec!(
 			TestVector{