/usr/share/gocode/src/github.com/twstrike/otr3/receive.go is in golang-github-twstrike-otr3-dev 0.0~git20161015.0.744856d-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 | package otr3
// Receive handles a message from a peer. It returns a human readable message and zero or more messages to send back to the peer.
func (c *Conversation) Receive(m ValidMessage) (plain MessagePlaintext, toSend []ValidMessage, err error) {
return c.receiveUnit(m, true)
}
// Receive handles a message from a peer. It returns a human readable message and zero or more messages to send back to the peer.
func (c *Conversation) receiveUnit(m ValidMessage, forgetFragments bool) (plain MessagePlaintext, toSend []ValidMessage, err error) {
message := makeCopy(m)
defer wipeBytes(message)
if !c.Policies.isOTREnabled() {
return c.receiveWithoutOTR(message)
}
msgType := guessMessageType(message)
var messagesToSend []messageWithHeader
shouldForgetFragment := true
switch msgType {
case msgGuessError:
return c.withInjectionsPlain(c.receiveErrorMessage(message))
case msgGuessQuery:
messagesToSend, err = c.receiveQueryMessage(message)
case msgGuessTaggedPlaintext:
plain, messagesToSend, err = c.receiveTaggedPlaintext(message)
case msgGuessNotOTR:
plain, messagesToSend, err = c.receivePlaintext(message)
case msgGuessV1KeyExch:
return nil, nil, errUnsupportedOTRVersion
case msgGuessFragment:
shouldForgetFragment = false
c.fragmentationContext, err = c.receiveFragment(c.fragmentationContext, message)
if fragmentsFinished(c.fragmentationContext) {
return c.withInjectionsPlain(c.receiveUnit(c.fragmentationContext.frag, false))
}
case msgGuessUnknown:
c.messageEvent(MessageEventReceivedMessageUnrecognized)
case msgGuessDHCommit, msgGuessDHKey, msgGuessRevealSig, msgGuessSignature, msgGuessData:
plain, messagesToSend, err = c.receiveEncoded(encodedMessage(message))
}
if shouldForgetFragment && forgetFragments {
c.fragmentationContext = forgetFragment()
}
return c.withInjectionsPlain(c.toSendEncoded(plain, messagesToSend, err))
}
func (c *Conversation) receiveWithoutOTR(message ValidMessage) (MessagePlaintext, []ValidMessage, error) {
return MessagePlaintext(message), nil, nil
}
func withoutPotentialSpaceStart(msg []byte) []byte {
if len(msg) > 0 && msg[0] == ' ' {
return msg[1:]
}
return msg
}
func (c *Conversation) receiveErrorMessage(message ValidMessage) (plain MessagePlaintext, toSend []ValidMessage, err error) {
msg := MessagePlaintext(makeCopy(message[len(errorMarker):]))
if c.Policies.has(errorStartAKE) {
toSend = []ValidMessage{c.QueryMessage()}
}
if c.msgState == encrypted {
c.updateMayRetransmitTo(retransmitWithPrefix)
}
c.messageEventWithMessage(MessageEventReceivedMessageGeneralError, withoutPotentialSpaceStart(msg))
return
}
func (c *Conversation) encodeAndCombine(toSend []messageWithHeader) []ValidMessage {
var result []ValidMessage
for _, ts := range toSend {
result = append(result, c.fragEncode(ts)...)
}
return result
}
func (c *Conversation) toSendEncoded(plain MessagePlaintext, toSend []messageWithHeader, err error) (MessagePlaintext, []ValidMessage, error) {
if err != nil || len(toSend) == 0 || len(toSend[0]) == 0 {
return plain, nil, err
}
return plain, c.encodeAndCombine(toSend), err
}
func (c *Conversation) receiveEncoded(message encodedMessage) (MessagePlaintext, []messageWithHeader, error) {
decodedMessage, err := c.decode(message)
if err != nil {
return nil, nil, err
}
return c.receiveDecoded(decodedMessage)
}
func (c *Conversation) checkPlaintextPolicies(plain MessagePlaintext) {
if c.whitespaceState == whitespaceSent {
c.whitespaceState = whitespaceRejected
}
if c.msgState != plainText || c.Policies.has(requireEncryption) {
c.messageEventWithMessage(MessageEventReceivedMessageUnencrypted, plain)
}
}
func (c *Conversation) receivePlaintext(message ValidMessage) (plain MessagePlaintext, toSend []messageWithHeader, err error) {
p := makeCopy(message)
plain = MessagePlaintext(p)
c.checkPlaintextPolicies(plain)
return
}
func (c *Conversation) receiveTaggedPlaintext(message ValidMessage) (plain MessagePlaintext, toSend []messageWithHeader, err error) {
plain, toSend, err = c.processWhitespaceTag(message)
c.checkPlaintextPolicies(plain)
return
}
func removeOTRMsgEnvelope(msg encodedMessage) []byte {
return msg[len(msgMarker) : len(msg)-1]
}
func (c *Conversation) decode(encoded encodedMessage) (messageWithHeader, error) {
encoded = removeOTRMsgEnvelope(encoded)
msg, err := b64decode(encoded)
if err != nil {
return nil, errInvalidOTRMessage
}
return msg, nil
}
func (c *Conversation) receiveDecoded(message messageWithHeader) (plain MessagePlaintext, toSend []messageWithHeader, err error) {
if err = c.checkVersion(message); err != nil {
return
}
var messageHeader, messageBody []byte
if messageHeader, messageBody, err = c.parseMessageHeader(message); err != nil {
if err == errReceivedMessageForOtherInstance {
err = nil
}
return
}
msgType := messageHeader[2]
switch msgType {
case msgTypeData:
return c.receiveDataMessage(messageHeader, messageBody)
default:
return c.receiveAKEMessage(msgType, messageBody)
}
}
func (c *Conversation) receiveAKEMessage(msgType byte, messageBody []byte) (plain MessagePlaintext, toSend []messageWithHeader, err error) {
toSend, err = c.potentialAuthError(c.processAKE(msgType, messageBody))
return
}
func (c *Conversation) receiveDataMessage(messageHeader, messageBody []byte) (plain MessagePlaintext, toSend []messageWithHeader, err error) {
plain, toSend, err = c.maybeHeartbeat(c.processDataMessage(messageHeader, messageBody))
if err != nil {
c.notifyDataMessageError(err)
}
return
}
func (c *Conversation) notifyDataMessageError(err error) {
var e ErrorCode
if err == errMessageNotInPrivate {
return
}
if isConflict(err) {
c.messageEvent(MessageEventReceivedMessageUnreadable)
e = ErrorCodeMessageUnreadable
} else {
c.messageEvent(MessageEventReceivedMessageMalformed)
e = ErrorCodeMessageMalformed
}
c.generatePotentialErrorMessage(e)
}
|