Re: Getting "Unexpected EOF from the server" when trying to connect to MS SQL Server 2014

2016-04-25 15:38 GMT+01:00 Pulver, Alex <[email protected]>:
> Thanks Frediano! Your input helped to resolve this :)
>
> The problem was combination of two things:
> * Our current FreeTDS installation was compiled with OpenSSL 0.9.8, and probably the server was using a newer version for handshake.
> * I was trying to use TDSVER=7.0 in all recent attempts, and didn't try to bump it again.
>
> To summarize, the following worked:
> * Compile FreeTDS with OpenSSL 1.0.1: ./configure --with-openssl=/.../openssl/1.0.1/bin/openssl
> * Try connecting with TDSVER=7.2 (8.0 also works of course): env TDSVER=8.0 /.../tsql -H <host> -p <port> -U <username> -P <password> -D <database>
>
> Regards,
> Alex
>

Great!

Please don't use 8.0 as a version. Microsoft renamed 8.0 to 7.1 quite
a while ago. In FreeTDS 1.0 we removed support for this old
(compatible) "8.0" version. So 7.2/7.3/7.4 are newer than the "8.0"
(which is the MS SQL Server 2000 protocol).

Frediano

>
> -----Original Message-----
> From: FreeTDS [mailto:[email protected]] On Behalf Of Frediano Ziglio
> Sent: Monday, April 25, 2016 17:14
> To: FreeTDS Development Group <[email protected]>
> Subject: Re: [freetds] Getting "Unexpected EOF from the server" when trying to connect to MS SQL Server 2014
>
> 2016-04-25 13:26 GMT+01:00 Pulver, Alex <[email protected]>:
>> Hi all,
>>
>> I am trying to connect to MS SQL 2014 Server from SLES11 host, using FreeTDS 0.95.51 version and its tsql utility. The server uses "Standard Mode" (SQL Server Authentication) and I am able to connect from Windows using SQL Server 2014 Management Studio.
>> Before sending this email I've read through FreeTDS troubleshooting, FAQ, domains page, config page, archives and various SO questions - tried the recommended configurations but with no luck (details below).
>>
>> The command being run is:
>> env TDSVER=7.0 TDSDUMP=/tmp/tdsdump.log TDSDUMPCONFIG=/tmp/tdsdumpconfig.log ./src/apps/tsql -H <host> -p <port> -U <username> -P <password> -D <database>
>>
>
> I would try with at least 7.2 version.
>
>> The output:
>> locale is "C"
>> locale charset is "ANSI_X3.4-1968"
>> using default charset "ISO-8859-1"
>> Setting <database> as default database in login packet
>> Error 20017 (severity 9):
>>         Unexpected EOF from the server
>> ...
>>
>> Tailing TDSDUMP along with the execution shows that error is happening after the login packet is sent and FreeTDS tries to process the login tokens:
>> login.c:852:quietly sending TDS 7+ login packet
>> token.c:327:tds_process_login_tokens()
>> <<
>> Error 20017 (severity 9):
>>         Unexpected EOF from the server
>>>>
>> query.c:3772:tds_disconnect()
>>
>> Looking on strace seems to confirm that server disconnects after login packet is received (poll() returns positive after sendto(), but recvfrom() returns 0):
>> write(5, "login.c:852:quietly sending TDS "..., 48) = 48
>> ...
>> poll([{fd=6, events=POLLOUT}, {fd=4, events=POLLIN}], 2, -1) = 1 ([{fd=6, revents=POLLOUT}])
>> sendto(6, "\20\1\0012\0\0\0\0*\1\0\0\0\0\0p\0\20\0\0\6\203\362\370U\354\0\0\0\0\0\0"..., 306, MSG_NOSIGNAL, NULL, 0) = 306
>> write(5, "token.c:327:tds_process_login_to"..., 39) = 39
>
> This means that server rejected the login. Like user/password wrong.
> Are you using Kerberos/SSPI or SQL logins?
>
>> poll([{fd=6, events=POLLIN}, {fd=4, events=POLLIN}], 2, -1) = 1 ([{fd=6, revents=POLLIN}])
>> recvfrom(6, "", 8, MSG_NOSIGNAL, NULL, NULL) = 0
>> write(5, "query.c:3772:tds_disconnect() \n", 31) = 31
>>
>> Things I tried listed in no particular order (assuming the issue is with authentication and not network):
>> * Use UTF-8 encoding
>
> This would change if you have extra ASCII in your username/password.
>
>> * Disable SSPI: ./configure --disable-sspi (so that trusted authentication will not be triggered)
>
> SSPI is supported only in Windows so it's not affecting your build.
>
>> * Compile with latest OpenSSL version we have installed: ./configure --with-openssl=/.../openssl/1.0.1/bin/openssl
>> * Explicitly disable OpenSSL: ./configure --without-openssl
>> * Modifying the code in ./src/tds/mem.c to disable check_ssl_hostname by setting it to 0 in both places it appears (assuming it triggers checking server's SSL certificate and fails to authenticate). Verified using debugger that *((tds)->login) object has check_ssl_hostname set to 0
>> * Modifying the code in ./src/tds/tls.c to change location of certificates pointed by ca_directory[] to a directory I know we have updated internal certificates
>>
>
> No, the check is done by FreeTDS, in this case the server is disconnecting.
>
>> Things I still need to check with MS SQL Server admins:
>> * Try to see if they can give me access to server-side log for my connection attempts
>> * Check if server requires two-way authentication for SQL Server Authentication - doesn't seem like it, but I will check
>>
>> If someone has any other ideas as to why the connection drops, or other things I can do to investigate further, I would really appreciate that!
>>
>
> You could try increasing the log level (see "debug flags" in
> http://www.freetds.org/userguide/freetdsconf.htm).
> Also I would try the "use ntlmv2" flag (same page above).
>
>> Thanks!
>> Alex
>
> Frediano
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