Advanced SSL Topics - Implementing SSL/TLS Using Cryptography and PKI - page 428

21:54:05.568432 IP localhost.8443 > localhost.37289: Flags [P.], ack 83, win
256, options [nop,nop,TS val 274087 ecr 274087], length 130

0x0000: 4500 00b6 f2e1 4000 4006 495e 7f00 0001 E.....@.@.I^....
0x0010: 7f00 0001 20fb 91a9 d260 dc47 d246 a65c .........`.G.F.\

Headshake
Header

TLS Header

0x0020: 8018 0100 feaa 0000 0101 080a 0004 2ea7 ................
0x0030: 0004 2ea7 1603 0100 4a02 0000 4603 014c ........J...F..L

0x0040: 743f 7dc9 fc4e af63 d94b e2e0 672e 5a0d t?}..N.c.K..g.Z.
0x0050: ea6b 91da 9e2f 2f48 f733 23d5 4b0d 8720 .k...//H.3#.K...

Same Session
Id

0x0060: be2e b988 f5bc 6412 5981 35f7 7e3b 2128 ......d.Y.5.~;!(
0x0070: f8cc 4e6f fc52 77fd a687 2ac5 0f1e cbbb ..No.Rw...*.....
0x0080: 000a 0014 0301 0001 0116 0301 0028 1d95 .............(..

Change Cipher
Spec

Finished
Message

0x0090: a8c8 56f3 841b 0046 4e40 29d9 6b83 036b ..V....FN@).k..k
0x00a0: c30f 624e c3b9 fc32 d8f2 9d1e 8ae5 6b18 ..bN...2......k.

0x00b0: cb75 d7a7 d311 .u....

The server responds with a server hello message containing the identical ses-
sion ID. If the session ID is different here, the client should begin negotiating a
new connection. If the session ID is the same, however, the client should expect
the server hello to be followed immediately by a change cipher spec message,
followed by a server fi nished.
The client follows up with its own change cipher spec and server fi nished mes-
sage; this is followed immediately by encrypted application data, as shown here:

21:54:05.572924 IP localhost.37289 > localhost.8443: Flags [P.], ack 131, win
265, options [nop,nop,TS val 274088 ecr 274087], length 6
0x0000: 4500 003a 88b2 4000 4006 b409 7f00 0001 E..:..@.@.......
0x0010: 7f00 0001 91a9 20fb d246 a65c d260 dcc9 .........F.\.`..
0x0020: 8018 0109 fe2e 0000 0101 080a 0004 2ea8 ................
0x0030: 0004 2ea7 1403 0100 0101 ..........
21:54:05.613696 IP localhost.37289 > localhost.8443: Flags [P.], ack 131, win
265, options [nop,nop,TS val 274098 ecr 274098], length 196
0x0000: 4500 00f8 88b3 4000 4006 b34a 7f00 0001 E.....@.@..J....
0x0010: 7f00 0001 91a9 20fb d246 a662 d260 dcc9 .........F.b.`..
0x0020: 8018 0109 feec 0000 0101 080a 0004 2eb2 ................
0x0030: 0004 2eb2 1603 0100 2892 32f1 da76 4138 ........(.2..vA8
0x0040: cb21 3a05 15f0 803b 34d3 e308 f12c 7aee .!:....;4....,z.
0x0050: 634f 9246 924d f6bd d646 9c92 3879 a882 cO.F.M...F..8y..
0x0060: 2e17 0301 0030 0127 7be8 e387 2b97 5f9c .....0.'{...+._.
0x0070: 8d2b 02fe 8587 a91a ef3a fa53 fb54 d577 .+.......:.S.T.w
0x0080: e62a 44fd 5e0d eaf1 769f c2a2 619c 27aa .*D.^...v...a.'.
0x0090: d619 fc02 3d81
…

Adding Session Resumption on the Server Side

How about supporting session resumption on the server side? The server has
to do quite a bit more work than the client. It must remember each session ID
it assigns and the master key associated with each.