long length checks & indentation

util/src/rlp/tests.rs

@@ -361,3 +361,17 @@ fn test_rlp_data_length_check()
 	let as_val: Result<String, DecoderError> = rlp.as_val();
 	assert_eq!(Err(DecoderError::RlpInconsistentLengthAndData), as_val);
 }
+
+#[test]
+fn test_rlp_long_data_length_check()
+{
+	let mut data: Vec<u8> = vec![0xb8, 255];
+	for _ in 0..253 {
+		data.push(b'c');
+	}
+
+	let rlp = UntrustedRlp::new(&data);
+
+	let as_val: Result<String, DecoderError> = rlp.as_val();
+	assert_eq!(Err(DecoderError::RlpInconsistentLengthAndData), as_val);
+}

util/src/rlp/untrusted_rlp.rs

@@ -346,8 +346,16 @@ impl<'a> Decoder for BasicDecoder<'a> {
 			Some(l @ 0xb8...0xbf) => {
 				let len_of_len = l as usize - 0xb7;
 				let begin_of_value = 1 as usize + len_of_len;
+				if bytes.len() < begin_of_value {
+					return Err(DecoderError::RlpInconsistentLengthAndData);
+				}
 				let len = try!(usize::from_bytes(&bytes[1..begin_of_value]));
-				Ok(try!(f(&bytes[begin_of_value..begin_of_value + len])))
+
+				let last_index_of_value = begin_of_value + len;
+				if bytes.len() < last_index_of_value {
+					return Err(DecoderError::RlpInconsistentLengthAndData);
+				}
+				Ok(try!(f(&bytes[begin_of_value..last_index_of_value])))
 			}
 			// we are reading value, not a list!
 			_ => Err(DecoderError::RlpExpectedToBeData)