Stub out Sha256 calls when fuzzing

src/ln/chan_utils.rs

@@ -7,9 +7,10 @@ use secp256k1::Secp256k1;
 use secp256k1;
 
 use crypto::digest::Digest;
-use crypto::sha2::Sha256;
 use crypto::ripemd160::Ripemd160;
 
+use util::sha2::Sha256;
+
 // Various functions for key derivation and transaction creation for use within channels. Primarily
 // used in Channel and ChannelMonitor.
 

src/ln/channel.rs

@@ -13,7 +13,6 @@ use secp256k1;
 
 use crypto::digest::Digest;
 use crypto::hkdf::{hkdf_extract,hkdf_expand};
-use crypto::sha2::Sha256;
 
 use ln::msgs;
 use ln::msgs::{HandleError, MsgEncodable};
@@ -23,6 +22,7 @@ use ln::chan_utils::{TxCreationKeys,HTLCOutputInCommitment};
 use ln::chan_utils;
 use chain::chaininterface::{FeeEstimator,ConfirmationTarget};
 use util::{transaction_utils,rng};
+use util::sha2::Sha256;
 
 use std::default::Default;
 use std::cmp;

src/ln/channelmanager.rs

@@ -18,11 +18,11 @@ use ln::router::Route;
 use ln::msgs;
 use ln::msgs::{HandleError,ChannelMessageHandler,MsgEncodable,MsgDecodable};
 use util::{byte_utils, events, internal_traits, rng};
+use util::sha2::Sha256;
 
 use crypto::mac::{Mac,MacResult};
 use crypto::hmac::Hmac;
 use crypto::digest::Digest;
-use crypto::sha2::Sha256;
 use crypto::symmetriccipher::SynchronousStreamCipher;
 use crypto::chacha20::ChaCha20;
 

src/ln/channelmonitor.rs

@@ -4,7 +4,6 @@ use bitcoin::blockdata::script::Script;
 use bitcoin::util::hash::Sha256dHash;
 use bitcoin::util::bip143;
 
-use crypto::sha2::Sha256;
 use crypto::digest::Digest;
 
 use secp256k1::{Secp256k1,Message,Signature};
@@ -14,6 +13,7 @@ use ln::msgs::HandleError;
 use ln::chan_utils;
 use ln::chan_utils::HTLCOutputInCommitment;
 use chain::chaininterface::{ChainListener, ChainWatchInterface, BroadcasterInterface};
+use util::sha2::Sha256;
 
 use std::collections::HashMap;
 use std::sync::{Arc,Mutex};

src/ln/peer_channel_encryptor.rs

@@ -7,12 +7,12 @@ use secp256k1::ecdh::SharedSecret;
 
 use crypto::digest::Digest;
 use crypto::hkdf::{hkdf_extract,hkdf_expand};
-use crypto::sha2::Sha256;
 
 use crypto::aead::{AeadEncryptor, AeadDecryptor};
 
 use util::chacha20poly1305rfc::ChaCha20Poly1305RFC;
 use util::{byte_utils,rng};
+use util::sha2::Sha256;
 
 // Sha256("Noise_XK_secp256k1_ChaChaPoly_SHA256")
 const NOISE_CK: [u8; 32] = [0x26, 0x40, 0xf5, 0x2e, 0xeb, 0xcd, 0x9e, 0x88, 0x29, 0x58, 0x95, 0x1c, 0x79, 0x42, 0x50, 0xee, 0xdb, 0x28, 0x00, 0x2c, 0x05, 0xd7, 0xdc, 0x2e, 0xa0, 0xf1, 0x95, 0x40, 0x60, 0x42, 0xca, 0xf1];

src/util/mod.rs

@@ -5,6 +5,7 @@ pub(crate) mod byte_utils;
 pub(crate) mod chacha20poly1305rfc;
 pub(crate) mod internal_traits;
 pub(crate) mod rng;
+pub(crate) mod sha2;
 
 #[cfg(test)]
 pub(crate) mod test_utils;

src/util/sha2.rs

@@ -0,0 +1,37 @@
+#[cfg(not(feature = "fuzztarget"))]
+pub use crypto::sha2::Sha256;
+
+#[cfg(feature = "fuzztarget")]
+mod fuzzy_sha {
+	use crypto::digest::Digest;
+	use crypto::sha2;
+
+	#[derive(Clone, Copy)]
+	pub struct Sha256 {
+		state: sha2::Sha256,
+	}
+
+	impl Sha256 {
+		pub fn new() -> Sha256 {
+			Sha256 {
+				state: sha2::Sha256::new(),
+			}
+		}
+	}
+
+	impl Digest for Sha256 {
+		fn result(&mut self, data: &mut [u8]) {
+			self.state.result(data);
+			for i in 1..32 {
+				data[i] = 0;
+			}
+		}
+
+		fn input(&mut self, data: &[u8]) { self.state.input(data); }
+		fn reset(&mut self) { self.state.reset(); }
+		fn output_bits(&self) -> usize { self.state.output_bits() }
+		fn block_size(&self) -> usize { self.state.block_size() }
+	}
+}
+#[cfg(feature = "fuzztarget")]
+pub use self::fuzzy_sha::Sha256;