1 files changed, 355 insertions, 0 deletions
diff --git a/teleirc/matterbridge/vendor/github.com/lrstanley/girc/cap.go b/teleirc/matterbridge/vendor/github.com/lrstanley/girc/cap.go
new file mode 100644
index 0000000..631b925
--- /dev/null
+++ b/teleirc/matterbridge/vendor/github.com/lrstanley/girc/cap.go
@@ -0,0 +1,355 @@
+// 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 negotiation).
+		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:]
+			}
+		}
+	}
+
+	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)
+}