[ This question belongs on openssl-users, not openssl-dev. Please
reply only to openssl-users. ]
On Tue, Apr 26, 2016 at 05:17:46AM +0200, Alex Hultman wrote:
> SSL_write followed by SSL_shutdown does not actually send the data passed
> to SSL_write if the total data size sent is less than (on my system) 7-8
> bytes.
This does not happen in "openssl s_client". You're likely doing
something wrong.
In one window I start an openssl server:
$ cipher=ADH-DES-CBC3-SHA
$ seclev= # Make that seclev=":@SECLEVEL=0" with OpenSSL 1.1.0 or later
$ openssl s_server -quiet -cipher "$cipher$seclev" -nocert -accept 12345
I another window I start a client:
$ cipher=ADH-DES-CBC3-SHA
$ seclev= # Make that seclev=":@SECLEVEL=0" with OpenSSL 1.1.0 or later
echo XXX | openssl s_client -debug -no_ign_eof -cipher "$cipher$seclev" -connect localhost:12345
On the server side I see the expected output:
XXX
On the client side after lots of handshake messages:
>>> ??? [length 0005]
17 03 03 00 24
write to 0x7f7f8bd003d0 [0x7f7f8c80b203] (41 bytes => 41 (0x29))
0000 - 17 03 03 00 24 c2 19 ea-c6 f1 a8 c7 74 31 50 3d ....$.......t1P=
0010 - a1 2f fb f0 d5 4d 2e 85-e0 6a 18 86 27 6a 09 1d ./...M...j..'j..
0020 - de 98 4e 69 05 57 0f 4c-93 ..Ni.W.L.
DONE
>>> ??? [length 0005]
15 03 03 00 24
write to 0x7f7f8bd003d0 [0x7f7f8c80b203] (41 bytes => 41 (0x29))
0000 - 15 03 03 00 24 d2 94 f8-11 dd 69 81 f7 ab cc 8c ....$.....i.....
0010 - c4 13 4c 80 24 d7 50 10-b9 62 74 d7 21 86 16 78 ..L.$.P..bt.!..x
0020 - b4 83 87 da 5e 2f d9 5d-34 ....^/.]4
>>> TLS 1.2Alert [length 0002], warning close_notify
01 00
The first of these is the "XXX" encrypted to 16 bytes, and padded
with a 20-byte SHA1 MAC (the server and client negotiated TLS 1.2
with Encrypt-then-Mac). The second is the encrypted shutdown alert.
> Is this known behavior?
No.
--
Viktor.
