Editing Transport Layer Security (section)

====Handshake protocol====
Most messages exchanged during the setup of the TLS session are based on this record, unless an error or warning occurs and needs to be signaled by an Alert protocol record (see below), or the encryption mode of the session is modified by another record (see ChangeCipherSpec protocol below).

{|class="wikitable"style=width:95%;text-align:center
|+TLS record format for handshake protocol
|-
!scope=col|Offset
!scope=col style=width:22%|Byte+0
!scope=col style=width:22%|Byte+1
!scope=col style=width:22%|Byte+2
!scope=col style=width:22%|Byte+3
|-
!scope=row|Byte<br />0
|style=background:#dfd|22
|colspan=3{{N/A}}
|-
!scope=row rowspan=2|Bytes<br />1–4
|colspan=2 style=background:#fdd|Legacy version
|colspan=2 style=background:#fdd|Length
|-style=background:#fdd
|''(Major)''
|''(Minor)''
|''(bits 15–8)''
|''(bits 7–0)''
|-
!scope=row rowspan=2|Bytes<br />5–8
|rowspan=2|Message type
|colspan=3|Handshake message data length
|-style=font-size:90%;line-height:1.2
|''(bits 23–16)''
|''(bits 15–8)''
|''(bits 7–0)''
|-
!scope=row|Bytes<br />9–(''n''−1)
|colspan=4|Handshake message data
|-
!scope=row rowspan=2|Bytes<br />''n''–(''n''+3)
|rowspan=2 style=background:#fdd|Message type
|colspan=3 style=background:#fdd|Handshake message data length
|-style=background:#fdd
|''(bits 23–16)''
|''(bits 15–8)''
|''(bits 7–0)''
|-
!scope=row|Bytes<br />(''n''+4)–
|colspan=4 style=background:#fdd|Handshake message data
|}

;Message type
:This field identifies the handshake message type.

{|class=wikitable
|+Message types
|-
!scope=col|Code
!scope=col|Description
|-
!scope=row|0
|HelloRequest
|-
!scope=row|1
|ClientHello
|-
!scope=row|2
|ServerHello
|-
!scope=row|4
|NewSessionTicket
|-
!scope=row|8
|EncryptedExtensions (TLS 1.3 only)
|-
!scope=row|11
|Certificate
|-
!scope=row|12
|ServerKeyExchange
|-
!scope=row|13
|CertificateRequest
|-
!scope=row|14
|ServerHelloDone
|-
!scope=row|15
|CertificateVerify
|-
!scope=row|16
|ClientKeyExchange
|-
!scope=row|20
|Finished
|}

;Handshake message data length
:This is a 3-byte field indicating the length of the handshake data, not including the header.

Note that multiple handshake messages may be combined within one record.