Don't return error while converting hash to v1

Mark clientapproval as broken because of incorrect client_id parsing

bittorrent/bittorrent.go

@@ -13,7 +13,6 @@ import (
 )
 
 // PeerID represents a peer ID.
-// TODO: check if torrentV2 also changed this field size
 type PeerID [20]byte
 
 // PeerIDFromBytes creates a PeerID from a byte slice.
@@ -61,17 +60,14 @@ const(
 )
 
 var invalidHashSize = errors.New("InfoHash must be either 20 (for torrent V1) or 32 (V2) bytes")
-var isNotV1Hash = errors.New("InfoHash is not V1 (SHA1)")
 
 // BytesV1 returns 20-bytes length array of the corresponding InfoHash.
-// If InfoHash is not 20-bytes long (is torrent V2 hash) zeroed array and error returned
-func (i InfoHash) BytesV1() ([InfoHashV1Len]byte, error){
+// If InfoHash is V2 (32 bytes), it will be truncated to 20 bytes
+// according to BEP52.
+func (i InfoHash) BytesV1() [InfoHashV1Len]byte{
 	var bb [InfoHashV1Len]byte
-	if len(i) != InfoHashV1Len {
-		return bb, isNotV1Hash
-	}
 	copy(bb[:], i)
-	return bb, nil
+	return bb
 }
 
 // ValidateInfoHash validates input bytes size and returns it

bittorrent/client_id.go

@@ -1,22 +0,0 @@
-package bittorrent
-
-// ClientID represents the part of a PeerID that identifies a Peer's client
-// software.
-type ClientID [6]byte
-
-// NewClientID parses a ClientID from a PeerID.
-func NewClientID(pid PeerID) ClientID {
-	var cid ClientID
-	length := len(pid)
-	if length >= 6 {
-		if pid[0] == '-' {
-			if length >= 7 {
-				copy(cid[:], pid[1:7])
-			}
-		} else {
-			copy(cid[:], pid[:6])
-		}
-	}
-
-	return cid
-}

middleware/clientapproval/client_id.go

@@ -0,0 +1,27 @@
+// Package clientapproval XXX: implementation is broken, client ID is NOT 6 static bytes
+// refer:
+// - https://wiki.theory.org/BitTorrentSpecification#peer_id
+// - https://github.com/webtorrent/bittorrent-peerid/blob/master/lib/utils.js
+package clientapproval
+
+import "github.com/chihaya/chihaya/bittorrent"
+
+// ClientID represents the part of a PeerID that identifies a Peer's client
+// software.
+type ClientID [6]byte
+
+// NewClientID parses a ClientID from a PeerID.
+func NewClientID(pid bittorrent.PeerID) ClientID {
+	var cid ClientID
+	if pid[0] == '-' {
+		copy(cid[:], pid[1:7])
+	} else {
+		copy(cid[:], pid[:6])
+	}
+
+	return cid
+}
+
+func (cid ClientID) String() string {
+	return string(cid[:])
+}

middleware/clientapproval/client_id_test.go

@@ -1,6 +1,7 @@
-package bittorrent
+package clientapproval
 
 import (
+	"github.com/chihaya/chihaya/bittorrent"
 	"testing"
 )
 
@@ -45,8 +46,8 @@ func TestClientID(t *testing.T) {
 	for _, tt := range clientTable {
 		t.Run(tt.peerID, func(t *testing.T) {
 			var clientID ClientID
-			copy(clientID[:], []byte(tt.clientID))
-			parsedID := NewClientID(PeerIDFromString(tt.peerID))
+			copy(clientID[:], tt.clientID)
+			parsedID := NewClientID(bittorrent.PeerIDFromString(tt.peerID))
 			if parsedID != clientID {
 				t.Error("Incorrectly parsed peer ID", tt.peerID, "as", parsedID)
 			}

middleware/clientapproval/clientapproval.go

@@ -44,15 +44,15 @@ type Config struct {
 }
 
 type hook struct {
-	approved   map[bittorrent.ClientID]struct{}
-	unapproved map[bittorrent.ClientID]struct{}
+	approved   map[ClientID]struct{}
+	unapproved map[ClientID]struct{}
 }
 
 // NewHook returns an instance of the client approval middleware.
 func NewHook(cfg Config) (middleware.Hook, error) {
 	h := &hook{
-		approved:   make(map[bittorrent.ClientID]struct{}),
-		unapproved: make(map[bittorrent.ClientID]struct{}),
+		approved:   make(map[ClientID]struct{}),
+		unapproved: make(map[ClientID]struct{}),
 	}
 
 	if len(cfg.Whitelist) > 0 && len(cfg.Blacklist) > 0 {
@@ -64,7 +64,7 @@ func NewHook(cfg Config) (middleware.Hook, error) {
 		if len(cidBytes) != 6 {
 			return nil, errors.New("client ID " + cidString + " must be 6 bytes")
 		}
-		var cid bittorrent.ClientID
+		var cid ClientID
 		copy(cid[:], cidBytes)
 		h.approved[cid] = struct{}{}
 	}
@@ -74,7 +74,7 @@ func NewHook(cfg Config) (middleware.Hook, error) {
 		if len(cidBytes) != 6 {
 			return nil, errors.New("client ID " + cidString + " must be 6 bytes")
 		}
-		var cid bittorrent.ClientID
+		var cid ClientID
 		copy(cid[:], cidBytes)
 		h.unapproved[cid] = struct{}{}
 	}
@@ -83,7 +83,7 @@ func NewHook(cfg Config) (middleware.Hook, error) {
 }
 
 func (h *hook) HandleAnnounce(ctx context.Context, req *bittorrent.AnnounceRequest, resp *bittorrent.AnnounceResponse) (context.Context, error) {
-	clientID := bittorrent.NewClientID(req.Peer.ID)
+	clientID := NewClientID(req.Peer.ID)
 
 	if len(h.approved) > 0 {
 		if _, found := h.approved[clientID]; !found {

storage/storage_bench.go

@@ -16,14 +16,10 @@ type benchData struct {
 }
 
 func generateInfohashes() (a [1000]bittorrent.InfoHash) {
-	r := rand.New(rand.NewSource(0))
 	for i := range a {
-		b := [20]byte{}
-		n, err := r.Read(b[:])
-		if err != nil || n != 20 {
-			panic("unable to create random bytes")
-		}
-		a[i] = bittorrent.InfoHash(b)
+		b := make([]byte, 20)
+		rand.Read(b)
+		a[i], _ = bittorrent.InfoHashFromBytes(b)
 	}
 
 	return
@@ -44,7 +40,7 @@ func generatePeers() (a [1000]bittorrent.Peer) {
 		}
 		port := uint16(r.Uint32())
 		a[i] = bittorrent.Peer{
-			ID:   bittorrent.PeerID(id),
+			ID:   id,
 			IP:   bittorrent.IP{IP: net.IP(ip), AddressFamily: bittorrent.IPv4},
 			Port: port,
 		}