Vendor github.com/lrstanley/girc

1 files changed, 639 insertions, 0 deletions

diff --git a/vendor/github.com/lrstanley/girc/cap.go b/vendor/github.com/lrstanley/girc/cap.go
new file mode 100644
index 00000000..751135b3
--- /dev/null
+++ b/vendor/github.com/lrstanley/girc/cap.go
@@ -0,0 +1,639 @@
+// Copyright (c) Liam Stanley <me@liamstanley.io>. All rights reserved. Use
+// of this source code is governed by the MIT license that can be found in
+// the LICENSE file.
+
+package girc
+
+import (
+	"bytes"
+	"encoding/base64"
+	"fmt"
+	"io"
+	"sort"
+	"strings"
+)
+
+var possibleCap = map[string][]string{
+	"account-notify":    nil,
+	"account-tag":       nil,
+	"away-notify":       nil,
+	"batch":             nil,
+	"cap-notify":        nil,
+	"chghost":           nil,
+	"extended-join":     nil,
+	"invite-notify":     nil,
+	"message-tags":      nil,
+	"multi-prefix":      nil,
+	"userhost-in-names": nil,
+}
+
+func (c *Client) listCAP() {
+	if !c.Config.disableTracking {
+		c.write(&Event{Command: CAP, Params: []string{CAP_LS, "302"}})
+	}
+}
+
+func possibleCapList(c *Client) map[string][]string {
+	out := make(map[string][]string)
+
+	if c.Config.SASL != nil {
+		out["sasl"] = nil
+	}
+
+	for k := range c.Config.SupportedCaps {
+		out[k] = c.Config.SupportedCaps[k]
+	}
+
+	for k := range possibleCap {
+		out[k] = possibleCap[k]
+	}
+
+	return out
+}
+
+func parseCap(raw string) map[string][]string {
+	out := make(map[string][]string)
+	parts := strings.Split(raw, " ")
+
+	var val int
+
+	for i := 0; i < len(parts); i++ {
+		val = strings.IndexByte(parts[i], prefixTagValue) // =
+
+		// No value splitter, or has splitter but no trailing value.
+		if val < 1 || len(parts[i]) < val+1 {
+			// The capability doesn't contain a value.
+			out[parts[i]] = nil
+			continue
+		}
+
+		out[parts[i][:val]] = strings.Split(parts[i][val+1:], ",")
+	}
+
+	return out
+}
+
+// handleCAP attempts to find out what IRCv3 capabilities the server supports.
+// This will lock further registration until we have acknowledged the
+// capabilities.
+func handleCAP(c *Client, e Event) {
+	if len(e.Params) >= 2 && (e.Params[1] == CAP_NEW || e.Params[1] == CAP_DEL) {
+		c.listCAP()
+		return
+	}
+
+	// We can assume there was a failure attempting to enable a capability.
+	if len(e.Params) == 2 && e.Params[1] == CAP_NAK {
+		// Let the server know that we're done.
+		c.write(&Event{Command: CAP, Params: []string{CAP_END}})
+		return
+	}
+
+	possible := possibleCapList(c)
+
+	if len(e.Params) >= 2 && len(e.Trailing) > 1 && e.Params[1] == CAP_LS {
+		c.state.Lock()
+
+		caps := parseCap(e.Trailing)
+
+		for k := range caps {
+			if _, ok := possible[k]; !ok {
+				continue
+			}
+
+			if len(possible[k]) == 0 || len(caps[k]) == 0 {
+				c.state.tmpCap = append(c.state.tmpCap, k)
+				continue
+			}
+
+			var contains bool
+			for i := 0; i < len(caps[k]); i++ {
+				for j := 0; j < len(possible[k]); j++ {
+					if caps[k][i] == possible[k][j] {
+						// Assume we have a matching split value.
+						contains = true
+						goto checkcontains
+					}
+				}
+			}
+
+		checkcontains:
+			if !contains {
+				continue
+			}
+
+			c.state.tmpCap = append(c.state.tmpCap, k)
+		}
+		c.state.Unlock()
+
+		// Indicates if this is a multi-line LS. (2 args means it's the
+		// last LS).
+		if len(e.Params) == 2 {
+			// If we support no caps, just ack the CAP message and END.
+			if len(c.state.tmpCap) == 0 {
+				c.write(&Event{Command: CAP, Params: []string{CAP_END}})
+				return
+			}
+
+			// Let them know which ones we'd like to enable.
+			c.write(&Event{Command: CAP, Params: []string{CAP_REQ}, Trailing: strings.Join(c.state.tmpCap, " ")})
+
+			// Re-initialize the tmpCap, so if we get multiple 'CAP LS' requests
+			// due to cap-notify, we can re-evaluate what we can support.
+			c.state.Lock()
+			c.state.tmpCap = []string{}
+			c.state.Unlock()
+		}
+	}
+
+	if len(e.Params) == 2 && len(e.Trailing) > 1 && e.Params[1] == CAP_ACK {
+		c.state.Lock()
+		c.state.enabledCap = strings.Split(e.Trailing, " ")
+
+		// Do we need to do sasl auth?
+		wantsSASL := false
+		for i := 0; i < len(c.state.enabledCap); i++ {
+			if c.state.enabledCap[i] == "sasl" {
+				wantsSASL = true
+				break
+			}
+		}
+		c.state.Unlock()
+
+		if wantsSASL {
+			c.write(&Event{Command: AUTHENTICATE, Params: []string{c.Config.SASL.Method()}})
+			// Don't "CAP END", since we want to authenticate.
+			return
+		}
+
+		// Let the server know that we're done.
+		c.write(&Event{Command: CAP, Params: []string{CAP_END}})
+		return
+	}
+}
+
+// SASLMech is an representation of what a SASL mechanism should support.
+// See SASLExternal and SASLPlain for implementations of this.
+type SASLMech interface {
+	// Method returns the uppercase version of the SASL mechanism name.
+	Method() string
+	// Encode returns the response that the SASL mechanism wants to use. If
+	// the returned string is empty (e.g. the mechanism gives up), the handler
+	// will attempt to panic, as expectation is that if SASL authentication
+	// fails, the client will disconnect.
+	Encode(params []string) (output string)
+}
+
+// SASLExternal implements the "EXTERNAL" SASL type.
+type SASLExternal struct {
+	// Identity is an optional field which allows the client to specify
+	// pre-authentication identification. This means that EXTERNAL will
+	// supply this in the initial response. This usually isn't needed (e.g.
+	// CertFP).
+	Identity string `json:"identity"`
+}
+
+// Method identifies what type of SASL this implements.
+func (sasl *SASLExternal) Method() string {
+	return "EXTERNAL"
+}
+
+// Encode for external SALS authentication should really only return a "+",
+// unless the user has specified pre-authentication or identification data.
+// See https://tools.ietf.org/html/rfc4422#appendix-A for more info.
+func (sasl *SASLExternal) Encode(params []string) string {
+	if len(params) != 1 || params[0] != "+" {
+		return ""
+	}
+
+	if sasl.Identity != "" {
+		return sasl.Identity
+	}
+
+	return "+"
+}
+
+// SASLPlain contains the user and password needed for PLAIN SASL authentication.
+type SASLPlain struct {
+	User string `json:"user"` // User is the username for SASL.
+	Pass string `json:"pass"` // Pass is the password for SASL.
+}
+
+// Method identifies what type of SASL this implements.
+func (sasl *SASLPlain) Method() string {
+	return "PLAIN"
+}
+
+// Encode encodes the plain user+password into a SASL PLAIN implementation.
+// See https://tools.ietf.org/rfc/rfc4422.txt for more info.
+func (sasl *SASLPlain) Encode(params []string) string {
+	if len(params) != 1 || params[0] != "+" {
+		return ""
+	}
+
+	in := []byte(sasl.User)
+
+	in = append(in, 0x0)
+	in = append(in, []byte(sasl.User)...)
+	in = append(in, 0x0)
+	in = append(in, []byte(sasl.Pass)...)
+
+	return base64.StdEncoding.EncodeToString(in)
+}
+
+const saslChunkSize = 400
+
+func handleSASL(c *Client, e Event) {
+	if e.Command == RPL_SASLSUCCESS || e.Command == ERR_SASLALREADY {
+		// Let the server know that we're done.
+		c.write(&Event{Command: CAP, Params: []string{CAP_END}})
+		return
+	}
+
+	// Assume they want us to handle sending auth.
+	auth := c.Config.SASL.Encode(e.Params)
+
+	if auth == "" {
+		// Assume the SASL authentication method doesn't want to respond for
+		// some reason. The SASL spec and IRCv3 spec do not define a clear
+		// way to abort a SASL exchange, other than to disconnect, or proceed
+		// with CAP END.
+		c.rx <- &Event{Command: ERROR, Trailing: fmt.Sprintf(
+			"closing connection: invalid %s SASL configuration provided: %s",
+			c.Config.SASL.Method(), e.Trailing,
+		)}
+		return
+	}
+
+	// Send in "saslChunkSize"-length byte chunks. If the last chuck is
+	// exactly "saslChunkSize" bytes, send a "AUTHENTICATE +" 0-byte
+	// acknowledgement response to let the server know that we're done.
+	for {
+		if len(auth) > saslChunkSize {
+			c.write(&Event{Command: AUTHENTICATE, Params: []string{auth[0 : saslChunkSize-1]}, Sensitive: true})
+			auth = auth[saslChunkSize:]
+			continue
+		}
+
+		if len(auth) <= saslChunkSize {
+			c.write(&Event{Command: AUTHENTICATE, Params: []string{auth}, Sensitive: true})
+
+			if len(auth) == 400 {
+				c.write(&Event{Command: AUTHENTICATE, Params: []string{"+"}})
+			}
+			break
+		}
+	}
+	return
+}
+
+func handleSASLError(c *Client, e Event) {
+	if c.Config.SASL == nil {
+		c.write(&Event{Command: CAP, Params: []string{CAP_END}})
+		return
+	}
+
+	// Authentication failed. The SASL spec and IRCv3 spec do not define a
+	// clear way to abort a SASL exchange, other than to disconnect, or
+	// proceed with CAP END.
+	c.rx <- &Event{Command: ERROR, Trailing: "closing connection: " + e.Trailing}
+}
+
+// handleCHGHOST handles incoming IRCv3 hostname change events. CHGHOST is
+// what occurs (when enabled) when a servers services change the hostname of
+// a user. Traditionally, this was simply resolved with a quick QUIT and JOIN,
+// however CHGHOST resolves this in a much cleaner fashion.
+func handleCHGHOST(c *Client, e Event) {
+	if len(e.Params) != 2 {
+		return
+	}
+
+	c.state.Lock()
+	user := c.state.lookupUser(e.Source.Name)
+	if user != nil {
+		user.Ident = e.Params[0]
+		user.Host = e.Params[1]
+	}
+	c.state.Unlock()
+	c.state.notify(c, UPDATE_STATE)
+}
+
+// handleAWAY handles incoming IRCv3 AWAY events, for which are sent both
+// when users are no longer away, or when they are away.
+func handleAWAY(c *Client, e Event) {
+	c.state.Lock()
+	user := c.state.lookupUser(e.Source.Name)
+	if user != nil {
+		user.Extras.Away = e.Trailing
+	}
+	c.state.Unlock()
+	c.state.notify(c, UPDATE_STATE)
+}
+
+// handleACCOUNT handles incoming IRCv3 ACCOUNT events. ACCOUNT is sent when
+// a user logs into an account, logs out of their account, or logs into a
+// different account. The account backend is handled server-side, so this
+// could be NickServ, X (undernet?), etc.
+func handleACCOUNT(c *Client, e Event) {
+	if len(e.Params) != 1 {
+		return
+	}
+
+	account := e.Params[0]
+	if account == "*" {
+		account = ""
+	}
+
+	c.state.Lock()
+	user := c.state.lookupUser(e.Source.Name)
+	if user != nil {
+		user.Extras.Account = account
+	}
+	c.state.Unlock()
+	c.state.notify(c, UPDATE_STATE)
+}
+
+// handleTags handles any messages that have tags that will affect state. (e.g.
+// 'account' tags.)
+func handleTags(c *Client, e Event) {
+	if len(e.Tags) == 0 {
+		return
+	}
+
+	account, ok := e.Tags.Get("account")
+	if !ok {
+		return
+	}
+
+	c.state.Lock()
+	user := c.state.lookupUser(e.Source.Name)
+	if user != nil {
+		user.Extras.Account = account
+	}
+	c.state.Unlock()
+	c.state.notify(c, UPDATE_STATE)
+}
+
+const (
+	prefixTag      byte = 0x40 // @
+	prefixTagValue byte = 0x3D // =
+	prefixUserTag  byte = 0x2B // +
+	tagSeparator   byte = 0x3B // ;
+	maxTagLength   int  = 511  // 510 + @ and " " (space), though space usually not included.
+)
+
+// Tags represents the key-value pairs in IRCv3 message tags. The map contains
+// the encoded message-tag values. If the tag is present, it may still be
+// empty. See Tags.Get() and Tags.Set() for use with getting/setting
+// information within the tags.
+//
+// Note that retrieving and setting tags are not concurrent safe. If this is
+// necessary, you will need to implement it yourself.
+type Tags map[string]string
+
+// ParseTags parses out the key-value map of tags. raw should only be the tag
+// data, not a full message. For example:
+//   @aaa=bbb;ccc;example.com/ddd=eee
+// NOT:
+//   @aaa=bbb;ccc;example.com/ddd=eee :nick!ident@host.com PRIVMSG me :Hello
+func ParseTags(raw string) (t Tags) {
+	t = make(Tags)
+
+	if len(raw) > 0 && raw[0] == prefixTag {
+		raw = raw[1:]
+	}
+
+	parts := strings.Split(raw, string(tagSeparator))
+	var hasValue int
+
+	for i := 0; i < len(parts); i++ {
+		hasValue = strings.IndexByte(parts[i], prefixTagValue)
+
+		// The tag doesn't contain a value or has a splitter with no value.
+		if hasValue < 1 || len(parts[i]) < hasValue+1 {
+			if !validTag(parts[i]) {
+				continue
+			}
+
+			t[parts[i]] = ""
+			continue
+		}
+
+		// Check if tag key or decoded value are invalid.
+		if !validTag(parts[i][:hasValue]) || !validTagValue(tagDecoder.Replace(parts[i][hasValue+1:])) {
+			continue
+		}
+
+		t[parts[i][:hasValue]] = parts[i][hasValue+1:]
+	}
+
+	return t
+}
+
+// Len determines the length of the bytes representation of this tag map. This
+// does not include the trailing space required when creating an event, but
+// does include the tag prefix ("@").
+func (t Tags) Len() (length int) {
+	if t == nil {
+		return 0
+	}
+
+	return len(t.Bytes())
+}
+
+// Count finds how many total tags that there are.
+func (t Tags) Count() int {
+	if t == nil {
+		return 0
+	}
+
+	return len(t)
+}
+
+// Bytes returns a []byte representation of this tag map, including the tag
+// prefix ("@"). Note that this will return the tags sorted, regardless of
+// the order of how they were originally parsed.
+func (t Tags) Bytes() []byte {
+	if t == nil {
+		return []byte{}
+	}
+
+	max := len(t)
+	if max == 0 {
+		return nil
+	}
+
+	buffer := new(bytes.Buffer)
+	buffer.WriteByte(prefixTag)
+
+	var current int
+
+	// Sort the writing of tags so we can at least guarantee that they will
+	// be in order, and testable.
+	var names []string
+	for tagName := range t {
+		names = append(names, tagName)
+	}
+	sort.Strings(names)
+
+	for i := 0; i < len(names); i++ {
+		// Trim at max allowed chars.
+		if (buffer.Len() + len(names[i]) + len(t[names[i]]) + 2) > maxTagLength {
+			return buffer.Bytes()
+		}
+
+		buffer.WriteString(names[i])
+
+		// Write the value as necessary.
+		if len(t[names[i]]) > 0 {
+			buffer.WriteByte(prefixTagValue)
+			buffer.WriteString(t[names[i]])
+		}
+
+		// add the separator ";" between tags.
+		if current < max-1 {
+			buffer.WriteByte(tagSeparator)
+		}
+
+		current++
+	}
+
+	return buffer.Bytes()
+}
+
+// String returns a string representation of this tag map.
+func (t Tags) String() string {
+	if t == nil {
+		return ""
+	}
+
+	return string(t.Bytes())
+}
+
+// writeTo writes the necessary tag bytes to an io.Writer, including a trailing
+// space-separator.
+func (t Tags) writeTo(w io.Writer) (n int, err error) {
+	b := t.Bytes()
+	if len(b) == 0 {
+		return n, err
+	}
+
+	n, err = w.Write(b)
+	if err != nil {
+		return n, err
+	}
+
+	var j int
+	j, err = w.Write([]byte{eventSpace})
+	n += j
+
+	return n, err
+}
+
+// tagDecode are encoded -> decoded pairs for replacement to decode.
+var tagDecode = []string{
+	"\\:", ";",
+	"\\s", " ",
+	"\\\\", "\\",
+	"\\r", "\r",
+	"\\n", "\n",
+}
+var tagDecoder = strings.NewReplacer(tagDecode...)
+
+// tagEncode are decoded -> encoded pairs for replacement to decode.
+var tagEncode = []string{
+	";", "\\:",
+	" ", "\\s",
+	"\\", "\\\\",
+	"\r", "\\r",
+	"\n", "\\n",
+}
+var tagEncoder = strings.NewReplacer(tagEncode...)
+
+// Get returns the unescaped value of given tag key. Note that this is not
+// concurrent safe.
+func (t Tags) Get(key string) (tag string, success bool) {
+	if t == nil {
+		return "", false
+	}
+
+	if _, ok := t[key]; ok {
+		tag = tagDecoder.Replace(t[key])
+		success = true
+	}
+
+	return tag, success
+}
+
+// Set escapes given value and saves it as the value for given key. Note that
+// this is not concurrent safe.
+func (t Tags) Set(key, value string) error {
+	if t == nil {
+		t = make(Tags)
+	}
+
+	if !validTag(key) {
+		return fmt.Errorf("tag key %q is invalid", key)
+	}
+
+	value = tagEncoder.Replace(value)
+
+	if len(value) > 0 && !validTagValue(value) {
+		return fmt.Errorf("tag value %q of key %q is invalid", value, key)
+	}
+
+	// Check to make sure it's not too long here.
+	if (t.Len() + len(key) + len(value) + 2) > maxTagLength {
+		return fmt.Errorf("unable to set tag %q [value %q]: tags too long for message", key, value)
+	}
+
+	t[key] = value
+
+	return nil
+}
+
+// Remove deletes the tag frwom the tag map.
+func (t Tags) Remove(key string) (success bool) {
+	if t == nil {
+		return false
+	}
+
+	if _, success = t[key]; success {
+		delete(t, key)
+	}
+
+	return success
+}
+
+// validTag validates an IRC tag.
+func validTag(name string) bool {
+	if len(name) < 1 {
+		return false
+	}
+
+	// Allow user tags to be passed to validTag.
+	if len(name) >= 2 && name[0] == prefixUserTag {
+		name = name[1:]
+	}
+
+	for i := 0; i < len(name); i++ {
+		// A-Z, a-z, 0-9, -/._
+		if (name[i] < 0x41 || name[i] > 0x5A) && (name[i] < 0x61 || name[i] > 0x7A) && (name[i] < 0x2D || name[i] > 0x39) && name[i] != 0x5F {
+			return false
+		}
+	}
+
+	return true
+}
+
+// validTagValue valids a decoded IRC tag value. If the value is not decoded
+// with tagDecoder first, it may be seen as invalid.
+func validTagValue(value string) bool {
+	for i := 0; i < len(value); i++ {
+		// Don't allow any invisible chars within the tag, or semicolons.
+		if value[i] < 0x21 || value[i] > 0x7E || value[i] == 0x3B {
+			return false
+		}
+	}
+	return true
+}