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