go-xmpp/component.go
Mickael Remond c6f0d03f60 Add support for delegation namespace packet parsing
Refactor and clean up pubsub & pep files
2019-06-18 14:36:56 +02:00

258 lines
7.1 KiB
Go

package xmpp // import "gosrc.io/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'>"
type ComponentOptions struct {
// =================================
// Component Connection Info
// Domain is the XMPP server subdomain that the component will handle
Domain string
// Secret is the "password" used by the XMPP server to secure component access
Secret string
// Address is the XMPP Host and port to connect to. Host is of
// the form 'serverhost:port' i.e "localhost:8888"
Address string
// =================================
// Component discovery
// Component human readable name, that will be shown in XMPP discovery
Name string
// Typical categories and types: https://xmpp.org/registrar/disco-categories.html
Category string
Type string
// =================================
// Communication with developer client / StreamManager
// Packet channel
RecvChannel chan Packet
// Track and broadcast connection state
EventManager
}
// 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 {
ComponentOptions
router *Router
// TCP level connection
conn net.Conn
// read / write
socketProxy io.ReadWriter // TODO
decoder *xml.Decoder
}
func NewComponent(opts ComponentOptions, r *Router) (*Component, error) {
c := Component{ComponentOptions: opts, router: r}
// Create a default channel that developers can override
c.RecvChannel = make(chan Packet)
return &c, nil
}
// Connect triggers component connection to XMPP server component port.
// TODO: Failed handshake should be a permanent error
func (c *Component) Connect() error {
var conn net.Conn
var err error
if conn, err = net.DialTimeout("tcp", c.Address, time.Duration(5)*time.Second); err != nil {
return err
}
c.conn = conn
// 1. Send stream open tag
if _, err := fmt.Fprintf(conn, componentStreamOpen, c.Domain, NSComponent, NSStream); err != nil {
return errors.New("cannot send stream open " + err.Error())
}
c.decoder = xml.NewDecoder(conn)
// 2. Initialize xml decoder and extract streamID from reply
streamId, err := initDecoder(c.decoder)
if err != nil {
return errors.New("cannot init decoder " + err.Error())
}
// 3. Authentication
if _, err := fmt.Fprintf(conn, "<handshake>%s</handshake>", c.handshake(streamId)); err != nil {
return errors.New("cannot send handshake " + err.Error())
}
// 4. Check server response for authentication
val, err := next(c.decoder)
if err != nil {
return err
}
switch v := val.(type) {
case StreamError:
return errors.New("handshake failed " + v.Error.Local)
case Handshake:
// Start the receiver go routine
go c.recv()
return nil
default:
return errors.New("expecting handshake result, got " + v.Name())
}
}
func (c *Component) Disconnect() {
_ = c.SendRaw("</stream:stream>")
// TODO: Add a way to wait for stream close acknowledgement from the server for clean disconnect
_ = c.conn.Close()
}
func (c *Component) SetHandler(handler EventHandler) {
c.Handler = handler
}
// Recv abstracts receiving preparsed XMPP packets from a channel.
// Channel allow client to receive / dispatch packets in for range loop.
// TODO: Deprecate this function in favor of reading directly from the RecvChannel ?
/*
func (c *Component) Recv() <-chan Packet {
return c.RecvChannel
}
*/
// Receiver Go routine receiver
func (c *Component) recv() (err error) {
for {
val, err := next(c.decoder)
if err != nil {
c.updateState(StateDisconnected)
return err
}
// Handle stream errors
switch p := val.(type) {
case StreamError:
c.router.Route(c, val)
c.streamError(p.Error.Local, p.Text)
return errors.New("stream error: " + p.Error.Local)
}
c.router.Route(c, val)
}
}
// Send marshalls XMPP stanza and sends it to the server.
func (c *Component) Send(packet Packet) error {
data, err := xml.Marshal(packet)
if err != nil {
return errors.New("cannot marshal packet " + err.Error())
}
if _, err := fmt.Fprintf(c.conn, string(data)); err != nil {
return errors.New("cannot send packet " + err.Error())
}
return nil
}
// SendRaw sends an XMPP stanza as a string to the server.
// It can be invalid XML or XMPP content. In that case, the server will
// disconnect the component. It is up to the user of this method to
// carefully craft the XML content to produce valid XMPP.
func (c *Component) SendRaw(packet string) error {
var err error
_, err = fmt.Fprintf(c.conn, packet)
return err
}
// 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
}
// ============================================================================
// Handshake Stanza
// Handshake is a stanza used by XMPP components to authenticate on XMPP
// component port.
type Handshake struct {
XMLName xml.Name `xml:"jabber:component:accept handshake"`
// TODO Add handshake value with test for proper serialization
// Value string `xml:",innerxml"`
}
func (Handshake) Name() string {
return "component:handshake"
}
// Handshake decoding wrapper
type handshakeDecoder struct{}
var handshake handshakeDecoder
func (handshakeDecoder) decode(p *xml.Decoder, se xml.StartElement) (Handshake, error) {
var packet Handshake
err := p.DecodeElement(&packet, &se)
return packet, err
}
// ============================================================================
// Component delegation
// XEP-0355
// Delegation can be used both on message (for delegated) and IQ (for Forwarded),
// depending on the context.
type Delegation struct {
MsgExtension
XMLName xml.Name `xml:"urn:xmpp:delegation:1 delegation"`
Forwarded Forwarded // This is used in iq to wrap delegated iqs
Delegated Delegated // This is used in a message to confirm delegated namespace
}
func (d *Delegation) Namespace() string {
return d.XMLName.Space
}
type Forwarded struct {
XMLName xml.Name `xml:"urn:xmpp:forward:0 forwarded"`
IQ IQ
Message Message
Presence Presence
}
type Delegated struct {
XMLName xml.Name `xml:"delegated"`
Namespace string `xml:"namespace,attr,omitempty"`
}
func init() {
TypeRegistry.MapExtension(PKTMessage, xml.Name{"urn:xmpp:delegation:1", "delegation"}, Delegation{})
TypeRegistry.MapExtension(PKTIQ, xml.Name{"urn:xmpp:delegation:1", "delegation"}, Delegation{})
}
/*
TODO: Add support for discovery management directly in component
TODO: Support multiple identities on disco info
TODO: Support returning features on disco info
*/