Parse torrent and fetch peers

torrent/torrent.go

@@ -0,0 +1,65 @@
+package torrent
+
+import (
+	"bytes"
+	"crypto/rand"
+	"crypto/sha1"
+	"fmt"
+	"io"
+
+	"github.com/jackpal/bencode-go"
+)
+
+const port = 6881
+
+// Info info
+type Info struct {
+	Pieces      string `bencode:"pieces"`
+	PieceLength int    `bencode:"piece length"`
+	Length      int    `bencode:"length"`
+	Name        string `bencode:"name"`
+}
+
+// Torrent torrent
+type Torrent struct {
+	Announce string `bencode:"announce"`
+	Info     Info   `bencode:"info"`
+}
+
+// Download downloads a torrent
+func (to *Torrent) Download() error {
+	peerID := make([]byte, 20)
+	_, err := rand.Read(peerID)
+	if err != nil {
+		return err
+	}
+
+	tracker := Tracker{
+		PeerID:  peerID,
+		Torrent: to,
+		Port:    port,
+	}
+	peers, err := tracker.getPeers()
+	fmt.Println(peers)
+	return nil
+}
+
+// Open parses a torrent file
+func Open(r io.Reader) (*Torrent, error) {
+	to := Torrent{}
+	err := bencode.Unmarshal(r, &to)
+	if err != nil {
+		return nil, err
+	}
+	return &to, nil
+}
+
+func (i *Info) hash() ([]byte, error) {
+	var buf bytes.Buffer
+	err := bencode.Marshal(&buf, *i)
+	if err != nil {
+		return nil, err
+	}
+	h := sha1.Sum(buf.Bytes())
+	return h[:], nil
+}