105 lines
3.1 KiB
Go
105 lines
3.1 KiB
Go
// SPDX-FileCopyrightText: 2023 The Pion community <https://pion.ly>
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// SPDX-License-Identifier: MIT
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package dtls
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/*
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DTLS messages are grouped into a series of message flights, according
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to the diagrams below. Although each flight of messages may consist
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of a number of messages, they should be viewed as monolithic for the
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purpose of timeout and retransmission.
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https://tools.ietf.org/html/rfc4347#section-4.2.4
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Message flights for full handshake:
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Client Server
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------ ------
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Waiting Flight 0
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ClientHello --------> Flight 1
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<------- HelloVerifyRequest Flight 2
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ClientHello --------> Flight 3
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ServerHello \
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Certificate* \
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ServerKeyExchange* Flight 4
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CertificateRequest* /
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<-------- ServerHelloDone /
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Certificate* \
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ClientKeyExchange \
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CertificateVerify* Flight 5
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[ChangeCipherSpec] /
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Finished --------> /
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[ChangeCipherSpec] \ Flight 6
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<-------- Finished /
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Message flights for session-resuming handshake (no cookie exchange):
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Client Server
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------ ------
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Waiting Flight 0
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ClientHello --------> Flight 1
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ServerHello \
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[ChangeCipherSpec] Flight 4b
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<-------- Finished /
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[ChangeCipherSpec] \ Flight 5b
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Finished --------> /
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[ChangeCipherSpec] \ Flight 6
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<-------- Finished /
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*/
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type flightVal uint8
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const (
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flight0 flightVal = iota + 1
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flight1
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flight2
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flight3
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flight4
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flight4b
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flight5
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flight5b
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flight6
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)
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func (f flightVal) String() string {
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switch f {
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case flight0:
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return "Flight 0"
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case flight1:
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return "Flight 1"
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case flight2:
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return "Flight 2"
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case flight3:
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return "Flight 3"
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case flight4:
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return "Flight 4"
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case flight4b:
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return "Flight 4b"
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case flight5:
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return "Flight 5"
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case flight5b:
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return "Flight 5b"
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case flight6:
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return "Flight 6"
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default:
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return "Invalid Flight"
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}
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}
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func (f flightVal) isLastSendFlight() bool {
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return f == flight6 || f == flight5b
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}
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func (f flightVal) isLastRecvFlight() bool {
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return f == flight5 || f == flight4b
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}
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