Re: ncat reverse ssl does not work, "terminating subprocesses"

Thanks Daniel,  I'll wait for the next release.

--sctp does not work on Windows 7, it might be an openssl issue, but
I'm not sure:

libnsock nsock_trace_handler_callback(): Callback: SSL-CONNECT ERROR [The reques
ted protocol has not been configured into the system, or no implementation for i
t exists.  (10043)] for EID 9 [peer unspecified]
Ncat: The requested protocol has not been configured into the system, or no impl
ementation for it exists. .




On Tue, Mar 21, 2017 at 11:43 AM, Daniel Miller <[email protected]> wrote:
> Olivia,
>
> Thanks for reporting this. We have a similar bug in our tracker [1] that we
> think may be related. We also recently put in a fix for a similar issue, so
> I think this will be resolved in the next release. Until then, a few users
> have reported a successful workaround by using the --sctp option on both
> ends.
>
> The underlying cause is a failure in Ncat's server mode to correctly handle
> some return values of OpenSSL's SSL_read call, which are usually caused by a
> renegotiation in the SSL/TLS layer. Because of the way SCTP works and its
> differences with TCP, these return values do not occur when using the SCTP
> transport.
>
> If the --sctp workaround works for you, please let us know. Otherwise, I
> hope you can make do until the next Ncat release, which shouldn't be too far
> off.
>
> Dan
>
> On Mon, Mar 20, 2017 at 7:33 PM, Olivia Nelson <[email protected]>
> wrote:
>>
>> The client is a windows 7 machine, run cmd.exe and connect back to a
>> ubuntu server
>>
>> When I execute a command, the connection interrupts immediately.
>>
>> Any ideas?
>>
>> ==== server ====
>>
>> # ./ncat.linux -l -p 8888 --ssl -vv
>> Ncat: Version 7.40 ( https://nmap.org/ncat )
>> Ncat: Generating a temporary 1024-bit RSA key. Use --ssl-key and
>> --ssl-cert to use a permanent one.
>> Ncat: SHA-1 fingerprint: CC5E 8A28 A19F 9254 2BC5 869C DFDC 47C0 D566 4D87
>> Ncat: Listening on :::8888
>> Ncat: Listening on 0.0.0.0:8888
>> Ncat: Connection from 172.16.177.30.
>> Ncat: Connection from 172.16.177.30:49180.
>> Microsoft Windows [Version 6.1.7601]
>> Copyright (c) 2009 Microsoft Corporation.  All rights reserved.
>>
>> x:\>dir
>> NCAT DEBUG: Closing connection.
>>
>> ==== client ====
>>
>> x:>ncat 172.16.177.200 8888 -e cmd --ssl -vv
>> Ncat: Version 7.40 ( https://nmap.org/ncat )
>> NCAT DEBUG: Using trusted CA certificates from x:\ca-bundle.crt.
>> NCAT DEBUG: Unable to load trusted CA certificates from x:\ca-bundle.cr
>> t: error:02001002:system library:fopen:No such file or directory
>> NCAT DEBUG: Not doing certificate verification.
>> libnsock nsock_iod_new2(): nsock_iod_new (IOD #1)
>> libnsock nsock_connect_ssl(): SSL connection requested to
>> 172.16.177.200:8888/tc
>> p (IOD #1) EID 9
>> Ncat: Subject: CN=localhost
>> Ncat: Issuer: CN=localhost
>> Ncat: SHA-1 fingerprint: CC5E 8A28 A19F 9254 2BC5 869C DFDC 47C0 D566 4D87
>> Ncat: Certificate verification failed (self signed certificate).
>> libnsock nsock_trace_handler_callback(): Callback: SSL-CONNECT SUCCESS for
>> EID 9
>>  [172.16.177.200:8888]
>> Ncat: SSL connection to 172.16.177.200:8888.
>> Ncat: SHA-1 fingerprint: CC5E 8A28 A19F 9254 2BC5 869C DFDC 47C0 D566 4D87
>> libnsock nsock_iod_new2(): nsock_iod_new (IOD #2)
>> NCAT DEBUG: Executing: cmd
>> NCAT DEBUG: Terminating subprocesses
>> _______________________________________________
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>> https://nmap.org/mailman/listinfo/dev
>> Archived at http://seclists.org/nmap-dev/
>
>
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