Compiled for cygwin - client_converse: receive: unexpected internal error

[denniskniep]

Hello,

first of all thanks for your awesome work!

I am using your released binaries v2.0.0 with gitforwindows with OpenSSH_8.4p1 and it worked like a charm.

Now I am trying to make it running with MobaXTerm (cygwin)

What i have done so far:

• cloned repo on tag v2.0.0
• ./setup-x86.exe -root <path> -q -P gcc-core -P gcc-g++ -P libssl-deve -P automake -P autoconf -P libtool
• autoconf --install
• ./configure
• make
• Copied src/.libs/winhello.dll

Executed
SSH_SK_PROVIDER=<path>/winhello.dll ssh-keygen -vvv -t ecdsa-sk -f ./fido

After a warning (already read in other issues, that this should be no problem):
WinHello API Error: Is User available=0, User=0

Then the following error is returned:

client_converse: receive: unexpected internal error
debug3: reap_helper: pid=7640
reap_helper: helper exited abnormally
Key enrollment failed: unexpected internal error

Any ideas what could be the problem?

[tavrez]

Hello, thanks for reporting.
Could you provide more log output? I need to see some lines before client_converse line.

[denniskniep]

sure, hope the complete log helps:

SSH_SK_PROVIDER=<path>/winhello.dll ssh-keygen -vvv -t ecdsa-sk -f ./fido

Generating public/private ecdsa-sk key pair.
You may need to touch your authenticator to authorize key generation.
debug3: start_helper: started pid=7640
debug3: ssh_msg_send: type 5
debug3: ssh_msg_recv entering
debug1: start_helper: starting /usr/sbin/ssh-sk-helper
debug1: sshsk_enroll: provider "<path>/winhello.dll", device "(null)", application "ssh:", userid "(null)", flags 0x01, challenge len 0
debug1: sshsk_enroll: using random challenge
debug1: sshsk_open: provider <path>/winhello.dll implements version 0x00070000
init_winhello: WARNING! This should not be like this! WinHello API Error: Is user available=0, User=0.
client_converse: receive: unexpected internal error
debug3: reap_helper: pid=7640
reap_helper: helper exited abnormally
Key enrollment failed: unexpected internal error

[tavrez]

Seems like helper is terminated without doing anything, do you have libfido2 and libcbor installed in your cygwin environment? Winhello do not need them but they are dependencies of ssh-sk-helper so they need to be installed correctly.

…

On Sat, Jan 23, 2021 at 7:22 PM denniskniep ***@***.***> wrote: sure, hope the complete log helps: SSH_SK_PROVIDER=<path>/winhello.dll ssh-keygen -vvv -t ecdsa-sk -f ./fido Generating public/private ecdsa-sk key pair. You may need to touch your authenticator to authorize key generation. debug3: start_helper: started pid=7640 debug3: ssh_msg_send: type 5 debug3: ssh_msg_recv entering debug1: start_helper: starting /usr/sbin/ssh-sk-helper debug1: sshsk_enroll: provider "<path>/winhello.dll", device "(null)", application "ssh:", userid "(null)", flags 0x01, challenge len 0 debug1: sshsk_enroll: using random challenge debug1: sshsk_open: provider <path>/winhello.dll implements version 0x00070000 init_winhello: WARNING! This should not be like this! WinHello API Error: Is user available=0, User=0. client_converse: receive: unexpected internal error debug3: reap_helper: pid=7640 reap_helper: helper exited abnormally Key enrollment failed: unexpected internal error — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#8 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACFM2DPLS3GTJS2P6XLDDRLS3LWCXANCNFSM4WPXHCMQ> .

[denniskniep]

Yes, they are both installed:

[tavrez]

I think it is because of mobaXterm launching terminal as a child process, but I'm not sure
Can you add some debug print like this(change msg number each time):

skdebug(__func__, "debug msg 1");

in src/winhello.c before line 296, after line 296 and after line 298 and re-compile and re-run it to see how far my code is going before crash?

[denniskniep]

Added statements here:

        skdebug(__func__, "debug msg 1");

        HWND hWnd = GetForegroundWindow();

        skdebug(__func__, "debug msg 1");

        HRESULT hr = webAuthNAuthenticatorMakeCredential(hWnd, &rpInfo, &userInfo, &WebAuthNCredentialParameters, &WebAuthNClientData, &WebAuthNCredentialOptions, &pWebAuthNCredentialAttestation);

Debug statements not showing up.
I added further debug lines to make sure modifications are compiled

sk_enroll: START
init_winhello: TEST v1
init_winhello: WARNING! This should not be like this! WinHello API Error: Is user available=0, User=0.
client_converse: receive: unexpected internal error
debug3: reap_helper: pid=13470
reap_helper: helper exited abnormally
Key enrollment failed: unexpected internal error

[tavrez]

Weird, all the lines between init and GetForegroundWindow are just memory allocation and variable assignments. If you can, add a debug line between all the lines to be able to specify exactly which line is causing the crash.

…

On Sat, Jan 23, 2021 at 11:27 PM denniskniep ***@***.***> wrote: Debug statements not showing up. I added further debug lines to make sure modifications are compiled sk_enroll: START init_winhello: TEST v1 init_winhello: WARNING! This should not be like this! WinHello API Error: Is user available=0, User=0. client_converse: receive: unexpected internal error debug3: reap_helper: pid=13470 reap_helper: helper exited abnormally Key enrollment failed: unexpected internal error — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#8 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACFM2DP76SOMK6AJ3FEOZXTS3MS4HANCNFSM4WPXHCMQ> .

[tavrez]

Also please verify that your compiled file and openssh has same architecture(x86 or x64)

[denniskniep]

compiled file and openssh has same architecture (checked with file)

/usr/bin/ssh.exe: PE32 executable (console) Intel 80386, for MS Windows
winhello.dll: PE32 executable (DLL) (console) Intel 80386, for MS Windows

Added following debug statements:

        skdebug(__func__, "debug msg 4");
        if (init_winhello() != 0)
        {
                skdebug(__func__, "debug msg 4a");
                return SSH_SK_ERR_UNSUPPORTED;
        }

        skdebug(__func__, "debug msg 4b");

and

        skdebug(__func__, "TEST v1");
        if (isUserAvailable == 0 && user == 1)
                return 0;
        /* FIXME: As MS said, this should not happen, but it's happening! Contacted them but got no answer...
         * Related issue link: https://github.com/tavrez/openssh-sk-winhello/issues/1
         */
        skdebug(__func__, "WARNING! This should not be like this! WinHello API Error: Is user available=%d, User=%d.", isUserAvailable, user);
        return 0;

Result is:

debug1: sshsk_open: provider <path>/winhello.dll implements version 0x00070000
sk_enroll: START
sk_enroll: debug msg 1
sk_enroll: debug msg 2
sk_enroll: debug msg 3
sk_enroll: debug msg 4
init_winhello: TEST v1
init_winhello: WARNING! This should not be like this! WinHello API Error: Is user available=0, User=0.
client_converse: receive: unexpected internal error

....really weird

[tavrez]

I'll try to check it when I have more time.
For now, you can try using the internal implementation of OpenSSH(be sure to run mobaXterm as administrator)

[denniskniep]

Thanks a lot for your help!

I have to make a correction:
I used autoreconf --install during build and not autoconf --install as I mentioned above.

Sorry for that, but that should not make any trouble, right?

[tavrez]

autoreconf is correct, without it I think you can't compile at all.

[denniskniep]

Hi @tavrez,
did you find some time to check whats the problem?
Thanks

[tavrez]

Hey,
I'm going to release a new version soon(small bug fixes). I'll check for this before releasing