Security audit issues fixed (#1279)

* Restrict network key file permissions

* Check for overflow in str to bigint conversion

* RLP decoder overflow check

util/src/keys/directory.rs

@@ -18,6 +18,7 @@
 
 use common::*;
 use std::path::{PathBuf};
+use path::restrict_permissions_owner;
 
 const CURRENT_DECLARED_VERSION: u64 = 3;
 const MAX_KEY_FILE_LEN: u64 = 1024 * 80;
@@ -465,23 +466,6 @@ pub struct KeyDirectory {
 	cache_usage: RwLock<VecDeque<Uuid>>,
 }
 
-/// Restricts the permissions of given path only to the owner.
-#[cfg(not(windows))]
-pub fn restrict_permissions_owner(file_path: &Path) -> Result<(), i32>  {
-	let cstr = ::std::ffi::CString::new(file_path.to_str().unwrap()).unwrap();
-	match unsafe { ::libc::chmod(cstr.as_ptr(), ::libc::S_IWUSR | ::libc::S_IRUSR) } {
-		0 => Ok(()),
-		x => Err(x),
-	}
-}
-
-/// Restricts the permissions of given path only to the owner.
-#[cfg(windows)]
-pub fn restrict_permissions_owner(_file_path: &Path) -> Result<(), i32>  {
-	//TODO: implement me
-	Ok(())
-}
-
 impl KeyDirectory {
 	/// Initializes new cache directory context with a given `path`
 	pub fn new(path: &Path) -> KeyDirectory {

util/src/network/host.rs

@@ -41,6 +41,7 @@ use network::stats::NetworkStats;
 use network::error::{NetworkError, DisconnectReason};
 use network::discovery::{Discovery, TableUpdates, NodeEntry};
 use network::ip_utils::{map_external_address, select_public_address};
+use path::restrict_permissions_owner;
 
 type Slab<T> = ::slab::Slab<T, usize>;
 
@@ -946,13 +947,17 @@ fn save_key(path: &Path, key: &Secret) {
 		return;
 	};
 	path_buf.push("key");
-	let mut file = match fs::File::create(path_buf.as_path()) {
+	let path = path_buf.as_path();
+	let mut file = match fs::File::create(&path) {
 		Ok(file) => file,
 		Err(e) => {
 			warn!("Error creating key file: {:?}", e);
 			return;
 		}
 	};
+	if let Err(e) = restrict_permissions_owner(&path) {
+		warn!(target: "network", "Failed to modify permissions of the file (chmod: {})", e);
+	}
 	if let Err(e) = file.write(&key.hex().into_bytes()) {
 		warn!("Error writing key file: {:?}", e);
 	}

util/src/path.rs

@@ -15,6 +15,7 @@
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
 //! Path utilities
+use std::path::Path;
 
 /// Default ethereum paths
 pub mod ethereum {
@@ -62,3 +63,21 @@ pub mod ethereum {
 		pth
 	}
 }
+
+/// Restricts the permissions of given path only to the owner.
+#[cfg(not(windows))]
+pub fn restrict_permissions_owner(file_path: &Path) -> Result<(), i32>  {
+	let cstr = ::std::ffi::CString::new(file_path.to_str().unwrap()).unwrap();
+	match unsafe { ::libc::chmod(cstr.as_ptr(), ::libc::S_IWUSR | ::libc::S_IRUSR) } {
+		0 => Ok(()),
+		x => Err(x),
+	}
+}
+
+/// Restricts the permissions of given path only to the owner.
+#[cfg(windows)]
+pub fn restrict_permissions_owner(_file_path: &Path) -> Result<(), i32>  {
+	//TODO: implement me
+	Ok(())
+}
+

util/src/rlp/tests.rs

@@ -429,3 +429,10 @@ fn test_rlp_nested_empty_list_encode() {
 	assert_eq!(stream.drain()[..], [0xc2u8, 0xc0u8, 40u8][..]);
 }
 
+#[test]
+fn test_rlp_list_length_overflow() {
+	let data: Vec<u8> = vec![0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00];
+	let rlp = UntrustedRlp::new(&data);
+	let as_val: Result<String, DecoderError> = rlp.val_at(0);
+	assert_eq!(Err(DecoderError::RlpIsTooShort), as_val);
+}

util/src/rlp/untrusted_rlp.rs

@@ -334,9 +334,9 @@ impl<'a> BasicDecoder<'a> {
 	/// Return first item info.
 	fn payload_info(bytes: &[u8]) -> Result<PayloadInfo, DecoderError> {
 		let item = try!(PayloadInfo::from(bytes));
-		match item.header_len + item.value_len <= bytes.len() {
-			true => Ok(item),
-			false => Err(DecoderError::RlpIsTooShort),
+		match item.header_len.checked_add(item.value_len) { 
+			Some(x) if x <= bytes.len() => Ok(item), 
+			_ => Err(DecoderError::RlpIsTooShort), 
 		}
 	}
 }