From dca45a9b1846a59cd3c471294891b89c9d77db7b Mon Sep 17 00:00:00 2001
From: zzz <zzz@mail.i2p>
Date: Wed, 16 Sep 2020 14:42:11 +0000
Subject: [PATCH] i2psnark: Defensive checks for v2 format files and magnet
links
---
.../i2psnark/java/src/org/klomp/snark/MagnetURI.java | 8 ++++++++
apps/i2psnark/java/src/org/klomp/snark/MetaInfo.java | 12 +++++++++++-
apps/i2psnark/java/src/org/klomp/snark/Peer.java | 7 +++----
.../src/org/klomp/snark/web/I2PSnarkServlet.java | 4 ++++
4 files changed, 26 insertions(+), 5 deletions(-)
diff --git a/apps/i2psnark/java/src/org/klomp/snark/MagnetURI.java b/apps/i2psnark/java/src/org/klomp/snark/MagnetURI.java
index dadba5849d..2baa06436c 100644
--- a/apps/i2psnark/java/src/org/klomp/snark/MagnetURI.java
+++ b/apps/i2psnark/java/src/org/klomp/snark/MagnetURI.java
@@ -24,6 +24,13 @@ public class MagnetURI {
public static final String MAGNET_FULL = MAGNET + "?xt=urn:btih:";
/** http://sponge.i2p/files/maggotspec.txt */
public static final String MAGGOT = "maggot://";
+ /**
+ * https://blog.libtorrent.org/2020/09/bittorrent-v2/
+ * TODO, dup param parsing, as a dual v1/v2 link
+ * will contain two xt params
+ * @since 0.9.48
+ */
+ public static final String MAGNET_FULL_V2 = MAGNET + "?xt=urn:btmh:";
/**
* @param url non-null
@@ -35,6 +42,7 @@ public class MagnetURI {
if (url.startsWith(MAGNET)) {
// magnet:?xt=urn:btih:0691e40aae02e552cfcb57af1dca56214680c0c5&tr=http://tracker2.postman.i2p/announce.php
String xt = getParam("xt", url);
+ // TODO btmh
if (xt == null || !xt.startsWith("urn:btih:"))
throw new IllegalArgumentException();
ihash = xt.substring("urn:btih:".length());
diff --git a/apps/i2psnark/java/src/org/klomp/snark/MetaInfo.java b/apps/i2psnark/java/src/org/klomp/snark/MetaInfo.java
index 8e72164889..f4aeb21f4f 100644
--- a/apps/i2psnark/java/src/org/klomp/snark/MetaInfo.java
+++ b/apps/i2psnark/java/src/org/klomp/snark/MetaInfo.java
@@ -238,8 +238,18 @@ public class MetaInfo
piece_length = val.getInt();
val = info.get("pieces");
- if (val == null)
+ if (val == null) {
+ // BEP 52
+ // We do the check here because a torrent file could be combined v1/v2,
+ // so a version 2 value isn't by itself fatal
+ val = info.get("meta version");
+ if (val != null) {
+ int version = val.getInt();
+ if (version != 1)
+ throw new InvalidBEncodingException("Version " + version + " torrent file not supported");
+ }
throw new InvalidBEncodingException("Missing piece bytes");
+ }
piece_hashes = val.getBytes();
val = info.get("length");
diff --git a/apps/i2psnark/java/src/org/klomp/snark/Peer.java b/apps/i2psnark/java/src/org/klomp/snark/Peer.java
index 580d61bafe..ba633cb18f 100644
--- a/apps/i2psnark/java/src/org/klomp/snark/Peer.java
+++ b/apps/i2psnark/java/src/org/klomp/snark/Peer.java
@@ -81,15 +81,14 @@ public class Peer implements Comparable<Peer>
private long downloaded_old[] = {-1,-1,-1};
private static final byte[] HANDSHAKE = DataHelper.getASCII("BitTorrent protocol");
+ // See BEP 4 for definitions
// bytes per bt spec: 0011223344556677
private static final long OPTION_EXTENSION = 0x0000000000100000l;
private static final long OPTION_FAST = 0x0000000000000004l;
//private static final long OPTION_DHT = 0x0000000000000001l;
- /** we use a different bit since the compact format is different */
-/* no, let's use an extension message
- static final long OPTION_I2P_DHT = 0x0000000040000000l;
-*/
//private static final long OPTION_AZMP = 0x1000000000000000l;
+ // hybrid support TODO
+ private static final long OPTION_V2 = 0x0000000000000010L;
private long options;
private final boolean _isIncoming;
private int _totalCommentsSent;
diff --git a/apps/i2psnark/java/src/org/klomp/snark/web/I2PSnarkServlet.java b/apps/i2psnark/java/src/org/klomp/snark/web/I2PSnarkServlet.java
index a06470abd9..b4737ee610 100644
--- a/apps/i2psnark/java/src/org/klomp/snark/web/I2PSnarkServlet.java
+++ b/apps/i2psnark/java/src/org/klomp/snark/web/I2PSnarkServlet.java
@@ -2801,6 +2801,10 @@ public class I2PSnarkServlet extends BasicServlet {
* @since 0.8.4
*/
private void addMagnet(String url, File dataDir) {
+ if (url.startsWith(MagnetURI.MAGNET_FULL_V2)) {
+ _manager.addMessage("Version 2 magnet links are not supported");
+ return;
+ }
try {
MagnetURI magnet = new MagnetURI(_manager.util(), url);
String name = magnet.getName();
--
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