WIP: Limit TLV stream decoding to type ranges

Author: jkczyz

lightning/src/offers/invoice.rs

@@ -16,13 +16,14 @@ use core::time::Duration;
 use io;
 use ln::PaymentHash;
 use ln::features::OfferFeatures;
+use ln::msgs::DecodeError;
 use offers::merkle::{SignatureTlvStream, self};
 use offers::offer::OfferTlvStream;
 use offers::parse::{ParseError, SemanticError};
 use offers::payer::PayerTlvStream;
 use offers::invoice_request::{InvoiceRequestContents, InvoiceRequestTlvStream};
 use onion_message::BlindedPath;
-use util::ser::{HighZeroBytesDroppedBigSize, Readable, WithoutLength, Writeable, Writer};
+use util::ser::{HighZeroBytesDroppedBigSize, SeekReadable, WithoutLength, Writeable, Writer};
 
 use prelude::*;
 
@@ -83,12 +84,19 @@ impl TryFrom<Vec<u8>> for Invoice {
 	type Error = ParseError;
 
 	fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
-		let tlv_stream: FullInvoiceTlvStream = Readable::read(&mut &bytes[..])?;
+		let mut cursor = io::Cursor::new(bytes);
+		let tlv_stream: FullInvoiceTlvStream = SeekReadable::read(&mut cursor)?;
+
+		if cursor.position() < cursor.get_ref().len() as u64 {
+			return Err(ParseError::Decode(DecodeError::InvalidValue));
+		}
+
+		let bytes = cursor.into_inner();
 		Invoice::try_from((bytes, tlv_stream))
 	}
 }
 
-tlv_stream!(InvoiceTlvStream, InvoiceTlvStreamRef, {
+tlv_stream!(InvoiceTlvStream, InvoiceTlvStreamRef, 160..240, {
 	(160, paths: (Vec<BlindedPath>, WithoutLength)),
 	(162, payinfo: (Vec<BlindedPayInfo>, WithoutLength)),
 	(164, created_at: (u64, HighZeroBytesDroppedBigSize)),
@@ -136,6 +144,18 @@ type ParsedInvoice = (Vec<u8>, FullInvoiceTlvStream);
 type FullInvoiceTlvStream =
 	(PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, InvoiceTlvStream, SignatureTlvStream);
 
+impl SeekReadable for FullInvoiceTlvStream {
+	fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
+		let payer = SeekReadable::read(r)?;
+		let offer = SeekReadable::read(r)?;
+		let invoice_request = SeekReadable::read(r)?;
+		let invoice = SeekReadable::read(r)?;
+		let signature = SeekReadable::read(r)?;
+
+		Ok((payer, offer, invoice_request, invoice, signature))
+	}
+}
+
 type PartialInvoiceTlvStream =
 	(PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, InvoiceTlvStream);