go-xmpp/component.go

105 lines
2.6 KiB
Go

package xmpp
import (
"crypto/sha1"
"encoding/hex"
"encoding/xml"
"errors"
"fmt"
"io"
"net"
"time"
)
const componentStreamOpen = "<?xml version='1.0'?><stream:stream to='%s' xmlns='%s' xmlns:stream='%s'>"
// Component implements an XMPP extension allowing to extend XMPP server
// using external components. Component specifications are defined
// in XEP-0114, XEP-0355 and XEP-0356.
type Component struct {
Host string
Secret string
// TCP level connection
conn net.Conn
// read / write
socketProxy io.ReadWriter // TODO
decoder *xml.Decoder
}
type Handshake struct {
XMLName xml.Name `xml:"jabber:component:accept handshake"`
}
// Handshake generates an authentication token based on StreamID and shared secret.
func (c *Component) Handshake(streamId string) string {
// 1. Concatenate the Stream ID received from the server with the shared secret.
concatStr := streamId + c.Secret
// 2. Hash the concatenated string according to the SHA1 algorithm, i.e., SHA1( concat (sid, password)).
h := sha1.New()
h.Write([]byte(concatStr))
hash := h.Sum(nil)
// 3. Ensure that the hash output is in hexadecimal format, not binary or base64.
// 4. Convert the hash output to all lowercase characters.
encodedStr := hex.EncodeToString(hash)
return encodedStr
}
// TODO Helper to prepare connection string
func Open(connStr string) error {
c := Component{Host: connStr, Secret: "mypass"}
var conn net.Conn
var err error
if conn, err = net.DialTimeout("tcp", "localhost:8888", time.Duration(5)*time.Second); err != nil {
return err
}
c.conn = conn
// TODO send stream open and check for reply
// Send stream open tag
componentHost := connStr // TODO Fix me: Extract componentID + secret
if _, err := fmt.Fprintf(conn, componentStreamOpen, componentHost, NSComponent, NSStream); err != nil {
fmt.Println("cannot send stream open.")
return err
}
c.decoder = xml.NewDecoder(conn)
// Initialize xml decoder and extract streamID from reply
streamId, err := initDecoder(c.decoder)
if err != nil {
fmt.Println("cannot init decoder")
return err
}
fmt.Println("StreamID = ", streamId)
// Authentication
if _, err := fmt.Fprintf(conn, "<handshake>%s</handshake>", c.Handshake(streamId)); err != nil {
fmt.Println("cannot send stream open.")
return err
}
// Next message should be either success or failure.
name, val, err := next(c.decoder)
if err != nil {
fmt.Println(err)
return err
}
switch v := val.(type) {
case *StreamError:
fmt.Printf("error: %s", v.Error.Local)
case *Handshake:
fmt.Println("Component connected")
default:
return errors.New("unexpected packet, got " + name.Local + " in " + name.Space)
}
return nil
}