// 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 (
"fmt"
"strconv"
"strings"
"time"
)
// Something not in the list? Depending on the type of capability, you can
// enable it using Config.SupportedCaps.
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,
"msgid": nil,
"multi-prefix": nil,
"server-time": nil,
"userhost-in-names": nil,
// Supported draft versions, some may be duplicated above, this is for backwards
// compatibility.
"draft/message-tags-0.2": nil,
"draft/msgid": nil,
// sts, sasl, etc are enabled dynamically/depending on client configuration,
// so aren't included on this list.
// "echo-message" is supported, but it's not enabled by default. This is
// to prevent unwanted confusion and utilize less traffic if it's not needed.
// echo messages aren't sent to girc.PRIVMSG and girc.NOTICE handlers,
// rather they are only sent to girc.ALL_EVENTS handlers (this is to prevent
// each handler to have to check these types of things for each message).
// You can compare events using Event.Equals() to see if they are the same.
}
// https://ircv3.net/specs/extensions/server-time-3.2.html
// <value> ::= YYYY-MM-DDThh:mm:ss.sssZ
const capServerTimeFormat = "2006-01-02T15:04:05.999Z"
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
}
if !c.Config.DisableSTS && !c.Config.SSL {
// If fallback supported, and we failed recently, don't try negotiating STS.
// ONLY do this fallback if we're expired (primarily useful during the first
// sts negotation).
if time.Since(c.state.sts.lastFailed) < 5*time.Minute && !c.Config.DisableSTSFallback {
c.debug.Println("skipping strict transport policy negotiation; failed within the last 5 minutes")
} else {
out["sts"] = 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]map[string]string {
out := make(map[string]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]] = make(map[string]string)
for _, option := range strings.Split(parts[i][val+1:], ",") {
j := strings.Index(option, "=")
if j < 0 {
out[parts[i][:val]][option] = ""
} else {
out[parts[i][:val]][option[:j]] = option[j+1 : len(option)]
}
}
}
return out
}
// handleCAP attempts to find out what IRCv3 capabilities the server supports.
// This will lock further registration until we have acknowledged (or denied)
// the capabilities.
func handleCAP(c *Client, e Event) {
c.state.Lock()
defer c.state.Unlock()
if len(e.Params) >= 2 && e.Params[1] == CAP_DEL {
caps := parseCap(e.Last())
for cap := range caps {
// TODO: test the deletion.
delete(c.state.enabledCap, cap)
}
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)
// TODO: test the addition.
if len(e.Params) >= 3 && (e.Params[1] == CAP_LS || e.Params[1] == CAP_NEW) {
caps := parseCap(e.Last())
for capName := range caps {
if _, ok := possible[capName]; !ok {
continue
}
if len(possible[capName]) == 0 || len(caps[capName]) == 0 {
c.state.tmpCap[capName] = caps[capName]
continue
}
var contains bool
for capAttr := range caps[capName] {
for i := 0; i < len(possible[capName]); i++ {
if _, ok := caps[capName][capAttr]; ok {
// Assuming we have a matching attribute for the capability.
contains = true
goto checkcontains
}
}
}
checkcontains:
if !contains {
continue
}
c.state.tmpCap[capName] = caps[capName]
}
// Indicates if this is a multi-line LS. (3 args means it's the
// last LS).
if len(e.Params) == 3 {
// 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.
reqKeys := make([]string, len(c.state.tmpCap))
i := 0
for k := range c.state.tmpCap {
reqKeys[i] = k
i++
}
c.write(&Event{Command: CAP, Params: []string{CAP_REQ, strings.Join(reqKeys, " ")}})
}
}
if len(e.Params) == 3 && e.Params[1] == CAP_ACK {
enabled := strings.Split(e.Last(), " ")
for _, cap := range enabled {
if val, ok := c.state.tmpCap[cap]; ok {
c.state.enabledCap[cap] = val
} else {
c.state.enabledCap[cap] = nil
}
}
// Anything client side that needs to be setup post-capability-acknowledgement,
// should be done here.
// Handle STS, and only if it's something specifically we enabled (client
// may choose to disable girc automatic STS, and do it themselves).
if sts, sok := c.state.enabledCap["sts"]; sok && !c.Config.DisableSTS {
var isError bool
// Some things are updated in the policy depending on if the current
// connection is over tls or not.
var hasTLSConnection bool
if tlsState, _ := c.TLSConnectionState(); tlsState != nil {
hasTLSConnection = true
}
// "This key indicates the port number for making a secure connection.
// This key’s value MUST be a single port number. If the client is not
// already connected securely to the server at the requested hostname,
// it MUST close the insecure connection and reconnect securely on the
// stated port.
//
// To enforce an STS upgrade policy, servers MUST send this key to
// insecurely connected clients. Servers MAY send this key to securely
// connected clients, but it will be ignored."
//
// See: https://ircv3.net/specs/extensions/sts#the-port-key
if !hasTLSConnection {
if port, ok := sts["port"]; ok {
c.state.sts.upgradePort, _ = strconv.Atoi(port)
if c.state.sts.upgradePort < 21 {
isError = true
}
} else {
isError = true
}
}
// "This key is used on secure connections to indicate how long clients
// MUST continue to use secure connections when connecting to the server
// at the requested hostname. The value of this key MUST be given as a
// single integer which represents the number of seconds until the persistence
// policy expires.
//
// To enforce an STS persistence policy, servers MUST send this key to
// securely connected clients. Servers MAY send this key to all clients,
// but insecurely connected clients MUST ignore it."
//
// See: https://ircv3.net/specs/extensions/sts#the-duration-key
if hasTLSConnection {
if duration, ok := sts["duration"]; ok {
c.state.sts.persistenceDuration, _ = strconv.Atoi(duration)
c.state.sts.persistenceReceived = time.Now()
} else {
isError = true
}
}
// See: https://ircv3.net/specs/extensions/sts#the-preload-key
if hasTLSConnection {
if preload, ok := sts["preload"]; ok {
c.state.sts.preload, _ = strconv.ParseBool(preload)
}
}
if isError {
c.rx <- &Event{Command: ERROR, Params: []string{
fmt.Sprintf("closing connection: strict transport policy provided by server is invalid; possible MITM? config: %#v", sts),
}}
return
}
// Only upgrade if not already upgraded.
if !hasTLSConnection {
c.state.sts.beginUpgrade = true
c.RunHandlers(&Event{Command: STS_UPGRADE_INIT})
c.debug.Println("strict transport security policy provided by server; closing connection to begin upgrade...")
c.Close()
return
}
}
// 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.tmpCap = make(map[string]map[string]string)
if _, ok := c.state.enabledCap["sasl"]; ok && c.Config.SASL != nil {
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
}
}
// 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.Last()
}
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)
}