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split out sasl and tag handling

This commit is contained in:
Liam Stanley 2018-02-04 15:16:43 -05:00
parent 9e7aa2b446
commit a0910c7504
3 changed files with 457 additions and 439 deletions
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441
cap.go
View File

@ -5,11 +5,6 @@
package girc
import (
"bytes"
"encoding/base64"
"fmt"
"io"
"sort"
"strings"
)
@ -90,8 +85,8 @@ func parseCap(raw string) map[string][]string {
}
// handleCAP attempts to find out what IRCv3 capabilities the server supports.
// This will lock further registration until we have acknowledged the
// capabilities.
// This will lock further registration until we have acknowledged (or denied)
// 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()
@ -188,133 +183,6 @@ func handleCAP(c *Client, e Event) {
}
}
// 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,
@ -368,308 +236,3 @@ func handleACCOUNT(c *Client, e Event) {
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 = '@'
prefixTagValue byte = '='
prefixUserTag byte = '+'
tagSeparator byte = ';'
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())
}
// Equals compares two Tags for equality. With the msgid IRCv3 spec +\
// echo-message (amongst others), we may receive events that have msgid's,
// whereas our local events will not have the msgid. As such, don't compare
// all tags, only the necessary/important tags.
func (t Tags) Equals(tt Tags) bool {
// The only tag which is important at this time.
taccount, _ := t.Get("account")
ttaccount, _ := tt.Get("account")
return taccount == ttaccount
}
// Keys returns a slice of (unsorted) tag keys.
func (t Tags) Keys() (keys []string) {
keys = make([]string, 0, t.Count())
for key := range t {
keys = append(keys, key)
}
return keys
}
// 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] < 'A' || name[i] > 'Z') && (name[i] < 'a' || name[i] > 'z') && (name[i] < '-' || name[i] > '9') && name[i] != '_' {
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] < '!' || value[i] > '~' || value[i] == ';' {
return false
}
}
return true
}

137
cap_sasl.go Normal file
View File

@ -0,0 +1,137 @@
// 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 (
"encoding/base64"
"fmt"
)
// 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}
}

318
cap_tags.go Normal file
View File

@ -0,0 +1,318 @@
// 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"
"fmt"
"io"
"sort"
"strings"
)
// 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 = '@'
prefixTagValue byte = '='
prefixUserTag byte = '+'
tagSeparator byte = ';'
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())
}
// Equals compares two Tags for equality. With the msgid IRCv3 spec +\
// echo-message (amongst others), we may receive events that have msgid's,
// whereas our local events will not have the msgid. As such, don't compare
// all tags, only the necessary/important tags.
func (t Tags) Equals(tt Tags) bool {
// The only tag which is important at this time.
taccount, _ := t.Get("account")
ttaccount, _ := tt.Get("account")
return taccount == ttaccount
}
// Keys returns a slice of (unsorted) tag keys.
func (t Tags) Keys() (keys []string) {
keys = make([]string, 0, t.Count())
for key := range t {
keys = append(keys, key)
}
return keys
}
// 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] < 'A' || name[i] > 'Z') && (name[i] < 'a' || name[i] > 'z') && (name[i] < '-' || name[i] > '9') && name[i] != '_' {
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] < '!' || value[i] > '~' || value[i] == ';' {
return false
}
}
return true
}