[openssl-users] Version negotiation failure failure?

[Jordan Brown]

Any thoughts here?

On 8/31/2018 6:14 PM, Jordan Brown wrote:
>
> We're trying to nail down error reporting for TLS version mismatches,
> and we're seeing a couple of puzzling behaviors.
>
> First, and most puzzling... assume these two command lines:
>
>     $ openssl s_server -cert 2018.08.31.a.pem -key 2018.08.31.a.key
>     -no_tls1
>
>     $ openssl s_client -connect zel.us.oracle.com:4433 -tls1
>
> That is, I have a server that won't accept TLSv1.0, and a client that
> will only accept TLSv1.0.
>
> On the server side I see
>
>     1:error:14076102:SSL routines:SSL23_GET_CLIENT_HELLO:unsupported
>     protocol:s23_srvr.c:605:
>
> which makes perfect sense.  On the client side I see
>
>     4294956672:error:1409E0E5:SSL routines:ssl3_write_bytes:ssl
>     handshake failure:s3_pkt.c:659:
>
> which isn't as good, but is still sort of sensible.  But when I look
> at the packets exchanged, I see that the client sends a Client Hello,
> and the server responds with an ACK and then a FIN-ACK, with no data. 
> It just hangs up the phone.  This seems to violate RFC 5246 section
> E.1:  "If server supports (or is willing to use) only versions greater
> than client_version, it MUST send a "protocol_version" alert message
> and close the connection.".  Where's my protocol version alert?
>
> Of course my real case does not involve the sample client and server -
> it involves my own clients and servers - but I seem to see the same
> behavior with several servers (notably including the Apache httpd).
>
> This looks like it's the same as
> https://rt.openssl.org/Ticket/Display.html?id=2777 .  I'm using
> 1.0.2o.  (But I don't see anything relevant-looking in the 1.0.2p
> changes.)  I've seen similar behavior from 1.0.2o-fips.
>
> Am I missing something here, or is this a server-side bug?
>
>
> And then, on the client side...
>
> SSL_connect returns zero.  Exactly how that failure differs from a
> less-than-zero error is not clear, but OK.  The docs say to call
> SSL_get_error().  SSL_get_error() returns 5, SSL_ERROR_SYSCALL.  (That
> seems a little strange, since I don't think there's any system call
> errors here.)  The docs say to consult the error queue and errno. 
> ERR_peek_last_error( ) returns zero.  Errno is zero.  It failed, but
> nobody will tell me why.
>
> Am I missing something here, or is this a client library bug?
>
>
> (I have not tracked down exactly how the s_client tool ends up with a
> message.  It seems to use a more intricate mechanism than SSL_connect.)
>
>
> -- 
> Jordan Brown, Oracle Solaris
>
>

-- 
Jordan Brown, Oracle Solaris

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