diff options
Diffstat (limited to 'vendor/github.com/mattn/go-xmpp/xmpp.go')
-rw-r--r-- | vendor/github.com/mattn/go-xmpp/xmpp.go | 881 |
1 files changed, 881 insertions, 0 deletions
diff --git a/vendor/github.com/mattn/go-xmpp/xmpp.go b/vendor/github.com/mattn/go-xmpp/xmpp.go new file mode 100644 index 00000000..a792e5a3 --- /dev/null +++ b/vendor/github.com/mattn/go-xmpp/xmpp.go @@ -0,0 +1,881 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// TODO(rsc): +// More precise error handling. +// Presence functionality. +// TODO(mattn): +// Add proxy authentication. + +// Package xmpp implements a simple Google Talk client +// using the XMPP protocol described in RFC 3920 and RFC 3921. +package xmpp + +import ( + "bufio" + "bytes" + "crypto/md5" + "crypto/rand" + "crypto/tls" + "encoding/base64" + "encoding/binary" + "encoding/xml" + "errors" + "fmt" + "io" + "math/big" + "net" + "net/http" + "net/url" + "os" + "strings" + "time" +) + +const ( + nsStream = "http://etherx.jabber.org/streams" + nsTLS = "urn:ietf:params:xml:ns:xmpp-tls" + nsSASL = "urn:ietf:params:xml:ns:xmpp-sasl" + nsBind = "urn:ietf:params:xml:ns:xmpp-bind" + nsClient = "jabber:client" + nsSession = "urn:ietf:params:xml:ns:xmpp-session" +) + +// Default TLS configuration options +var DefaultConfig tls.Config + +// Cookie is a unique XMPP session identifier +type Cookie uint64 + +func getCookie() Cookie { + var buf [8]byte + if _, err := rand.Reader.Read(buf[:]); err != nil { + panic("Failed to read random bytes: " + err.Error()) + } + return Cookie(binary.LittleEndian.Uint64(buf[:])) +} + +// Client holds XMPP connection opitons +type Client struct { + conn net.Conn // connection to server + jid string // Jabber ID for our connection + domain string + p *xml.Decoder +} + +func (c *Client) JID() string { + return c.jid +} + +func connect(host, user, passwd string) (net.Conn, error) { + addr := host + + if strings.TrimSpace(host) == "" { + a := strings.SplitN(user, "@", 2) + if len(a) == 2 { + addr = a[1] + } + } + a := strings.SplitN(host, ":", 2) + if len(a) == 1 { + addr += ":5222" + } + proxy := os.Getenv("HTTP_PROXY") + if proxy == "" { + proxy = os.Getenv("http_proxy") + } + if proxy != "" { + url, err := url.Parse(proxy) + if err == nil { + addr = url.Host + } + } + c, err := net.Dial("tcp", addr) + if err != nil { + return nil, err + } + + if proxy != "" { + fmt.Fprintf(c, "CONNECT %s HTTP/1.1\r\n", host) + fmt.Fprintf(c, "Host: %s\r\n", host) + fmt.Fprintf(c, "\r\n") + br := bufio.NewReader(c) + req, _ := http.NewRequest("CONNECT", host, nil) + resp, err := http.ReadResponse(br, req) + if err != nil { + return nil, err + } + if resp.StatusCode != 200 { + f := strings.SplitN(resp.Status, " ", 2) + return nil, errors.New(f[1]) + } + } + return c, nil +} + +// Options are used to specify additional options for new clients, such as a Resource. +type Options struct { + // Host specifies what host to connect to, as either "hostname" or "hostname:port" + // If host is not specified, the DNS SRV should be used to find the host from the domainpart of the JID. + // Default the port to 5222. + Host string + + // User specifies what user to authenticate to the remote server. + User string + + // Password supplies the password to use for authentication with the remote server. + Password string + + // Resource specifies an XMPP client resource, like "bot", instead of accepting one + // from the server. Use "" to let the server generate one for your client. + Resource string + + // OAuthScope provides go-xmpp the required scope for OAuth2 authentication. + OAuthScope string + + // OAuthToken provides go-xmpp with the required OAuth2 token used to authenticate + OAuthToken string + + // OAuthXmlNs provides go-xmpp with the required namespaced used for OAuth2 authentication. This is + // provided to the server as the xmlns:auth attribute of the OAuth2 authentication request. + OAuthXmlNs string + + // TLS Config + TLSConfig *tls.Config + + // InsecureAllowUnencryptedAuth permits authentication over a TCP connection that has not been promoted to + // TLS by STARTTLS; this could leak authentication information over the network, or permit man in the middle + // attacks. + InsecureAllowUnencryptedAuth bool + + // NoTLS directs go-xmpp to not use TLS initially to contact the server; instead, a plain old unencrypted + // TCP connection should be used. (Can be combined with StartTLS to support STARTTLS-based servers.) + NoTLS bool + + // StartTLS directs go-xmpp to STARTTLS if the server supports it; go-xmpp will automatically STARTTLS + // if the server requires it regardless of this option. + StartTLS bool + + // Debug output + Debug bool + + // Use server sessions + Session bool + + // Presence Status + Status string + + // Status message + StatusMessage string +} + +// NewClient establishes a new Client connection based on a set of Options. +func (o Options) NewClient() (*Client, error) { + host := o.Host + c, err := connect(host, o.User, o.Password) + if err != nil { + return nil, err + } + + if strings.LastIndex(o.Host, ":") > 0 { + host = host[:strings.LastIndex(o.Host, ":")] + } + + client := new(Client) + if o.NoTLS { + client.conn = c + } else { + var tlsconn *tls.Conn + if o.TLSConfig != nil { + tlsconn = tls.Client(c, o.TLSConfig) + } else { + DefaultConfig.ServerName = host + tlsconn = tls.Client(c, &DefaultConfig) + } + if err = tlsconn.Handshake(); err != nil { + return nil, err + } + insecureSkipVerify := DefaultConfig.InsecureSkipVerify + if o.TLSConfig != nil { + insecureSkipVerify = o.TLSConfig.InsecureSkipVerify + } + if !insecureSkipVerify { + if err = tlsconn.VerifyHostname(host); err != nil { + return nil, err + } + } + client.conn = tlsconn + } + + if err := client.init(&o); err != nil { + client.Close() + return nil, err + } + + return client, nil +} + +// NewClient creates a new connection to a host given as "hostname" or "hostname:port". +// If host is not specified, the DNS SRV should be used to find the host from the domainpart of the JID. +// Default the port to 5222. +func NewClient(host, user, passwd string, debug bool) (*Client, error) { + opts := Options{ + Host: host, + User: user, + Password: passwd, + Debug: debug, + Session: false, + } + return opts.NewClient() +} + +// NewClientNoTLS creates a new client without TLS +func NewClientNoTLS(host, user, passwd string, debug bool) (*Client, error) { + opts := Options{ + Host: host, + User: user, + Password: passwd, + NoTLS: true, + Debug: debug, + Session: false, + } + return opts.NewClient() +} + +// Close closes the XMPP connection +func (c *Client) Close() error { + if c.conn != (*tls.Conn)(nil) { + return c.conn.Close() + } + return nil +} + +func saslDigestResponse(username, realm, passwd, nonce, cnonceStr, authenticate, digestURI, nonceCountStr string) string { + h := func(text string) []byte { + h := md5.New() + h.Write([]byte(text)) + return h.Sum(nil) + } + hex := func(bytes []byte) string { + return fmt.Sprintf("%x", bytes) + } + kd := func(secret, data string) []byte { + return h(secret + ":" + data) + } + + a1 := string(h(username+":"+realm+":"+passwd)) + ":" + nonce + ":" + cnonceStr + a2 := authenticate + ":" + digestURI + response := hex(kd(hex(h(a1)), nonce+":"+nonceCountStr+":"+cnonceStr+":auth:"+hex(h(a2)))) + return response +} + +func cnonce() string { + randSize := big.NewInt(0) + randSize.Lsh(big.NewInt(1), 64) + cn, err := rand.Int(rand.Reader, randSize) + if err != nil { + return "" + } + return fmt.Sprintf("%016x", cn) +} + +func (c *Client) init(o *Options) error { + + var domain string + var user string + a := strings.SplitN(o.User, "@", 2) + if len(o.User) > 0 { + if len(a) != 2 { + return errors.New("xmpp: invalid username (want user@domain): " + o.User) + } + user = a[0] + domain = a[1] + } // Otherwise, we'll be attempting ANONYMOUS + + // Declare intent to be a jabber client and gather stream features. + f, err := c.startStream(o, domain) + if err != nil { + return err + } + + // If the server requires we STARTTLS, attempt to do so. + if f, err = c.startTLSIfRequired(f, o, domain); err != nil { + return err + } + + if o.User == "" && o.Password == "" { + foundAnonymous := false + for _, m := range f.Mechanisms.Mechanism { + if m == "ANONYMOUS" { + fmt.Fprintf(c.conn, "<auth xmlns='%s' mechanism='ANONYMOUS' />\n", nsSASL) + foundAnonymous = true + break + } + } + if !foundAnonymous { + return fmt.Errorf("ANONYMOUS authentication is not an option and username and password were not specified") + } + } else { + // Even digest forms of authentication are unsafe if we do not know that the host + // we are talking to is the actual server, and not a man in the middle playing + // proxy. + if !c.IsEncrypted() && !o.InsecureAllowUnencryptedAuth { + return errors.New("refusing to authenticate over unencrypted TCP connection") + } + + mechanism := "" + for _, m := range f.Mechanisms.Mechanism { + if m == "X-OAUTH2" && o.OAuthToken != "" && o.OAuthScope != "" { + mechanism = m + // Oauth authentication: send base64-encoded \x00 user \x00 token. + raw := "\x00" + user + "\x00" + o.OAuthToken + enc := make([]byte, base64.StdEncoding.EncodedLen(len(raw))) + base64.StdEncoding.Encode(enc, []byte(raw)) + fmt.Fprintf(c.conn, "<auth xmlns='%s' mechanism='X-OAUTH2' auth:service='oauth2' "+ + "xmlns:auth='%s'>%s</auth>\n", nsSASL, o.OAuthXmlNs, enc) + break + } + if m == "PLAIN" { + mechanism = m + // Plain authentication: send base64-encoded \x00 user \x00 password. + raw := "\x00" + user + "\x00" + o.Password + enc := make([]byte, base64.StdEncoding.EncodedLen(len(raw))) + base64.StdEncoding.Encode(enc, []byte(raw)) + fmt.Fprintf(c.conn, "<auth xmlns='%s' mechanism='PLAIN'>%s</auth>\n", nsSASL, enc) + break + } + if m == "DIGEST-MD5" { + mechanism = m + // Digest-MD5 authentication + fmt.Fprintf(c.conn, "<auth xmlns='%s' mechanism='DIGEST-MD5'/>\n", nsSASL) + var ch saslChallenge + if err = c.p.DecodeElement(&ch, nil); err != nil { + return errors.New("unmarshal <challenge>: " + err.Error()) + } + b, err := base64.StdEncoding.DecodeString(string(ch)) + if err != nil { + return err + } + tokens := map[string]string{} + for _, token := range strings.Split(string(b), ",") { + kv := strings.SplitN(strings.TrimSpace(token), "=", 2) + if len(kv) == 2 { + if kv[1][0] == '"' && kv[1][len(kv[1])-1] == '"' { + kv[1] = kv[1][1 : len(kv[1])-1] + } + tokens[kv[0]] = kv[1] + } + } + realm, _ := tokens["realm"] + nonce, _ := tokens["nonce"] + qop, _ := tokens["qop"] + charset, _ := tokens["charset"] + cnonceStr := cnonce() + digestURI := "xmpp/" + domain + nonceCount := fmt.Sprintf("%08x", 1) + digest := saslDigestResponse(user, realm, o.Password, nonce, cnonceStr, "AUTHENTICATE", digestURI, nonceCount) + message := "username=\"" + user + "\", realm=\"" + realm + "\", nonce=\"" + nonce + "\", cnonce=\"" + cnonceStr + + "\", nc=" + nonceCount + ", qop=" + qop + ", digest-uri=\"" + digestURI + "\", response=" + digest + ", charset=" + charset + + fmt.Fprintf(c.conn, "<response xmlns='%s'>%s</response>\n", nsSASL, base64.StdEncoding.EncodeToString([]byte(message))) + + var rspauth saslRspAuth + if err = c.p.DecodeElement(&rspauth, nil); err != nil { + return errors.New("unmarshal <challenge>: " + err.Error()) + } + b, err = base64.StdEncoding.DecodeString(string(rspauth)) + if err != nil { + return err + } + fmt.Fprintf(c.conn, "<response xmlns='%s'/>\n", nsSASL) + break + } + } + if mechanism == "" { + return fmt.Errorf("PLAIN authentication is not an option: %v", f.Mechanisms.Mechanism) + } + } + // Next message should be either success or failure. + name, val, err := next(c.p) + if err != nil { + return err + } + switch v := val.(type) { + case *saslSuccess: + case *saslFailure: + // v.Any is type of sub-element in failure, + // which gives a description of what failed. + return errors.New("auth failure: " + v.Any.Local) + default: + return errors.New("expected <success> or <failure>, got <" + name.Local + "> in " + name.Space) + } + + // Now that we're authenticated, we're supposed to start the stream over again. + // Declare intent to be a jabber client. + if f, err = c.startStream(o, domain); err != nil { + return err + } + + // Generate a unique cookie + cookie := getCookie() + + // Send IQ message asking to bind to the local user name. + if o.Resource == "" { + fmt.Fprintf(c.conn, "<iq type='set' id='%x'><bind xmlns='%s'></bind></iq>\n", cookie, nsBind) + } else { + fmt.Fprintf(c.conn, "<iq type='set' id='%x'><bind xmlns='%s'><resource>%s</resource></bind></iq>\n", cookie, nsBind, o.Resource) + } + var iq clientIQ + if err = c.p.DecodeElement(&iq, nil); err != nil { + return errors.New("unmarshal <iq>: " + err.Error()) + } + if &iq.Bind == nil { + return errors.New("<iq> result missing <bind>") + } + c.jid = iq.Bind.Jid // our local id + c.domain = domain + + if o.Session { + //if server support session, open it + fmt.Fprintf(c.conn, "<iq to='%s' type='set' id='%x'><session xmlns='%s'/></iq>", xmlEscape(domain), cookie, nsSession) + } + + // We're connected and can now receive and send messages. + fmt.Fprintf(c.conn, "<presence xml:lang='en'><show>%s</show><status>%s</status></presence>", o.Status, o.StatusMessage) + + return nil +} + +// startTlsIfRequired examines the server's stream features and, if STARTTLS is required or supported, performs the TLS handshake. +// f will be updated if the handshake completes, as the new stream's features are typically different from the original. +func (c *Client) startTLSIfRequired(f *streamFeatures, o *Options, domain string) (*streamFeatures, error) { + // whether we start tls is a matter of opinion: the server's and the user's. + switch { + case f.StartTLS == nil: + // the server does not support STARTTLS + return f, nil + case f.StartTLS.Required != nil: + // the server requires STARTTLS. + case !o.StartTLS: + // the user wants STARTTLS and the server supports it. + } + var err error + + fmt.Fprintf(c.conn, "<starttls xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>\n") + var k tlsProceed + if err = c.p.DecodeElement(&k, nil); err != nil { + return f, errors.New("unmarshal <proceed>: " + err.Error()) + } + + tc := o.TLSConfig + if tc == nil { + tc = new(tls.Config) + *tc = DefaultConfig + //TODO(scott): we should consider using the server's address or reverse lookup + tc.ServerName = domain + } + t := tls.Client(c.conn, tc) + + if err = t.Handshake(); err != nil { + return f, errors.New("starttls handshake: " + err.Error()) + } + c.conn = t + + // restart our declaration of XMPP stream intentions. + tf, err := c.startStream(o, domain) + if err != nil { + return f, err + } + return tf, nil +} + +// startStream will start a new XML decoder for the connection, signal the start of a stream to the server and verify that the server has +// also started the stream; if o.Debug is true, startStream will tee decoded XML data to stderr. The features advertised by the server +// will be returned. +func (c *Client) startStream(o *Options, domain string) (*streamFeatures, error) { + if o.Debug { + c.p = xml.NewDecoder(tee{c.conn, os.Stderr}) + } else { + c.p = xml.NewDecoder(c.conn) + } + + _, err := fmt.Fprintf(c.conn, "<?xml version='1.0'?>\n"+ + "<stream:stream to='%s' xmlns='%s'\n"+ + " xmlns:stream='%s' version='1.0'>\n", + xmlEscape(domain), nsClient, nsStream) + if err != nil { + return nil, err + } + + // We expect the server to start a <stream>. + se, err := nextStart(c.p) + if err != nil { + return nil, err + } + if se.Name.Space != nsStream || se.Name.Local != "stream" { + return nil, fmt.Errorf("expected <stream> but got <%v> in %v", se.Name.Local, se.Name.Space) + } + + // Now we're in the stream and can use Unmarshal. + // Next message should be <features> to tell us authentication options. + // See section 4.6 in RFC 3920. + f := new(streamFeatures) + if err = c.p.DecodeElement(f, nil); err != nil { + return f, errors.New("unmarshal <features>: " + err.Error()) + } + return f, nil +} + +// IsEncrypted will return true if the client is connected using a TLS transport, either because it used. +// TLS to connect from the outset, or because it successfully used STARTTLS to promote a TCP connection to TLS. +func (c *Client) IsEncrypted() bool { + _, ok := c.conn.(*tls.Conn) + return ok +} + +// Chat is an incoming or outgoing XMPP chat message. +type Chat struct { + Remote string + Type string + Text string + Roster Roster + Other []string + Stamp time.Time +} + +type Roster []Contact + +type Contact struct { + Remote string + Name string + Group []string +} + +// Presence is an XMPP presence notification. +type Presence struct { + From string + To string + Type string + Show string + Status string +} + +type IQ struct { + ID string + From string + To string + Type string + Query []byte +} + +// Recv waits to receive the next XMPP stanza. +// Return type is either a presence notification or a chat message. +func (c *Client) Recv() (stanza interface{}, err error) { + for { + _, val, err := next(c.p) + if err != nil { + return Chat{}, err + } + switch v := val.(type) { + case *clientMessage: + stamp, _ := time.Parse( + "2006-01-02T15:04:05Z", + v.Delay.Stamp, + ) + chat := Chat{ + Remote: v.From, + Type: v.Type, + Text: v.Body, + Other: v.Other, + Stamp: stamp, + } + return chat, nil + case *clientQuery: + var r Roster + for _, item := range v.Item { + r = append(r, Contact{item.Jid, item.Name, item.Group}) + } + return Chat{Type: "roster", Roster: r}, nil + case *clientPresence: + return Presence{v.From, v.To, v.Type, v.Show, v.Status}, nil + case *clientIQ: + return IQ{ID: v.ID, From: v.From, To: v.To, Type: v.Type, Query: v.Query}, nil + } + } +} + +// Send sends the message wrapped inside an XMPP message stanza body. +func (c *Client) Send(chat Chat) (n int, err error) { + return fmt.Fprintf(c.conn, "<message to='%s' type='%s' xml:lang='en'>"+"<body>%s</body></message>", + xmlEscape(chat.Remote), xmlEscape(chat.Type), xmlEscape(chat.Text)) +} + +// SendOrg sends the original text without being wrapped in an XMPP message stanza. +func (c *Client) SendOrg(org string) (n int, err error) { + return fmt.Fprint(c.conn, org) +} + +func (c *Client) SendPresence(presence Presence) (n int, err error) { + return fmt.Fprintf(c.conn, "<presence from='%s' to='%s'/>", xmlEscape(presence.From), xmlEscape(presence.To)) +} + +// SendHtml sends the message as HTML as defined by XEP-0071 +func (c *Client) SendHtml(chat Chat) (n int, err error) { + return fmt.Fprintf(c.conn, "<message to='%s' type='%s' xml:lang='en'>"+ + "<body>%s</body>"+ + "<html xmlns='http://jabber.org/protocol/xhtml-im'><body xmlns='http://www.w3.org/1999/xhtml'>%s</body></html></message>", + xmlEscape(chat.Remote), xmlEscape(chat.Type), xmlEscape(chat.Text), chat.Text) +} + +// Roster asks for the chat roster. +func (c *Client) Roster() error { + fmt.Fprintf(c.conn, "<iq from='%s' type='get' id='roster1'><query xmlns='jabber:iq:roster'/></iq>\n", xmlEscape(c.jid)) + return nil +} + +// RFC 3920 C.1 Streams name space +type streamFeatures struct { + XMLName xml.Name `xml:"http://etherx.jabber.org/streams features"` + StartTLS *tlsStartTLS + Mechanisms saslMechanisms + Bind bindBind + Session bool +} + +type streamError struct { + XMLName xml.Name `xml:"http://etherx.jabber.org/streams error"` + Any xml.Name + Text string +} + +// RFC 3920 C.3 TLS name space +type tlsStartTLS struct { + XMLName xml.Name `xml:"urn:ietf:params:xml:ns:xmpp-tls starttls"` + Required *string `xml:"required"` +} + +type tlsProceed struct { + XMLName xml.Name `xml:"urn:ietf:params:xml:ns:xmpp-tls proceed"` +} + +type tlsFailure struct { + XMLName xml.Name `xml:"urn:ietf:params:xml:ns:xmpp-tls failure"` +} + +// RFC 3920 C.4 SASL name space +type saslMechanisms struct { + XMLName xml.Name `xml:"urn:ietf:params:xml:ns:xmpp-sasl mechanisms"` + Mechanism []string `xml:"mechanism"` +} + +type saslAuth struct { + XMLName xml.Name `xml:"urn:ietf:params:xml:ns:xmpp-sasl auth"` + Mechanism string `xml:",attr"` +} + +type saslChallenge string + +type saslRspAuth string + +type saslResponse string + +type saslAbort struct { + XMLName xml.Name `xml:"urn:ietf:params:xml:ns:xmpp-sasl abort"` +} + +type saslSuccess struct { + XMLName xml.Name `xml:"urn:ietf:params:xml:ns:xmpp-sasl success"` +} + +type saslFailure struct { + XMLName xml.Name `xml:"urn:ietf:params:xml:ns:xmpp-sasl failure"` + Any xml.Name `xml:",any"` +} + +// RFC 3920 C.5 Resource binding name space +type bindBind struct { + XMLName xml.Name `xml:"urn:ietf:params:xml:ns:xmpp-bind bind"` + Resource string + Jid string `xml:"jid"` +} + +// RFC 3921 B.1 jabber:client +type clientMessage struct { + XMLName xml.Name `xml:"jabber:client message"` + From string `xml:"from,attr"` + ID string `xml:"id,attr"` + To string `xml:"to,attr"` + Type string `xml:"type,attr"` // chat, error, groupchat, headline, or normal + + // These should technically be []clientText, but string is much more convenient. + Subject string `xml:"subject"` + Body string `xml:"body"` + Thread string `xml:"thread"` + + // Any hasn't matched element + Other []string `xml:",any"` + + Delay Delay `xml:"delay"` +} + +type Delay struct { + Stamp string `xml:"stamp,attr"` +} + +type clientText struct { + Lang string `xml:",attr"` + Body string `xml:"chardata"` +} + +type clientPresence struct { + XMLName xml.Name `xml:"jabber:client presence"` + From string `xml:"from,attr"` + ID string `xml:"id,attr"` + To string `xml:"to,attr"` + Type string `xml:"type,attr"` // error, probe, subscribe, subscribed, unavailable, unsubscribe, unsubscribed + Lang string `xml:"lang,attr"` + + Show string `xml:"show"` // away, chat, dnd, xa + Status string `xml:"status"` // sb []clientText + Priority string `xml:"priority,attr"` + Error *clientError +} + +type clientIQ struct { // info/query + XMLName xml.Name `xml:"jabber:client iq"` + From string `xml:"from,attr"` + ID string `xml:"id,attr"` + To string `xml:"to,attr"` + Type string `xml:"type,attr"` // error, get, result, set + Query []byte `xml:",innerxml"` + Error clientError + Bind bindBind +} + +type clientError struct { + XMLName xml.Name `xml:"jabber:client error"` + Code string `xml:",attr"` + Type string `xml:",attr"` + Any xml.Name + Text string +} + +type clientQuery struct { + Item []rosterItem +} + +type rosterItem struct { + XMLName xml.Name `xml:"jabber:iq:roster item"` + Jid string `xml:",attr"` + Name string `xml:",attr"` + Subscription string `xml:",attr"` + Group []string +} + +// Scan XML token stream to find next StartElement. +func nextStart(p *xml.Decoder) (xml.StartElement, error) { + for { + t, err := p.Token() + if err != nil && err != io.EOF || t == nil { + return xml.StartElement{}, err + } + switch t := t.(type) { + case xml.StartElement: + return t, nil + } + } +} + +// Scan XML token stream for next element and save into val. +// If val == nil, allocate new element based on proto map. +// Either way, return val. +func next(p *xml.Decoder) (xml.Name, interface{}, error) { + // Read start element to find out what type we want. + se, err := nextStart(p) + if err != nil { + return xml.Name{}, nil, err + } + + // Put it in an interface and allocate one. + var nv interface{} + switch se.Name.Space + " " + se.Name.Local { + case nsStream + " features": + nv = &streamFeatures{} + case nsStream + " error": + nv = &streamError{} + case nsTLS + " starttls": + nv = &tlsStartTLS{} + case nsTLS + " proceed": + nv = &tlsProceed{} + case nsTLS + " failure": + nv = &tlsFailure{} + case nsSASL + " mechanisms": + nv = &saslMechanisms{} + case nsSASL + " challenge": + nv = "" + case nsSASL + " response": + nv = "" + case nsSASL + " abort": + nv = &saslAbort{} + case nsSASL + " success": + nv = &saslSuccess{} + case nsSASL + " failure": + nv = &saslFailure{} + case nsBind + " bind": + nv = &bindBind{} + case nsClient + " message": + nv = &clientMessage{} + case nsClient + " presence": + nv = &clientPresence{} + case nsClient + " iq": + nv = &clientIQ{} + case nsClient + " error": + nv = &clientError{} + default: + return xml.Name{}, nil, errors.New("unexpected XMPP message " + + se.Name.Space + " <" + se.Name.Local + "/>") + } + + // Unmarshal into that storage. + if err = p.DecodeElement(nv, &se); err != nil { + return xml.Name{}, nil, err + } + + return se.Name, nv, err +} + +var xmlSpecial = map[byte]string{ + '<': "<", + '>': ">", + '"': """, + '\'': "'", + '&': "&", +} + +func xmlEscape(s string) string { + var b bytes.Buffer + for i := 0; i < len(s); i++ { + c := s[i] + if s, ok := xmlSpecial[c]; ok { + b.WriteString(s) + } else { + b.WriteByte(c) + } + } + return b.String() +} + +type tee struct { + r io.Reader + w io.Writer +} + +func (t tee) Read(p []byte) (n int, err error) { + n, err = t.r.Read(p) + if n > 0 { + t.w.Write(p[0:n]) + t.w.Write([]byte("\n")) + } + return +} |