RE: spnego sspi delegation [windows 7]

>-----Original Message-----
>From: curl-library <curl-library-bounces_at_cool.haxx.se> On Behalf Of Claudio
>via curl-library
>Sent: Wednesday, July 03, 2019 1:56 PM
>To: curl-library_at_cool.haxx.se
>Cc: Rinaldi, Claudio: Quants (LDN) <claudio.rinaldi_at_barclays.com>
>Subject: spnego sspi delegation [windows 7]
>
>
>This mail originated from outside our organisation - curl-library_at_cool.haxx.se
>
>Hello Everyone,
>
>I have a problem with curl lib in window which I have managed to quick fix it
>but I would need some further insight from experts.
>I am using curllib (or curl command) with --negotiate authentication on
>Windows and "--delegation always" (or policy) parameter. We use Kerberos
>authentication for what I know.
>The server I connect to will forward the request to a back end system and my
>credential must be provided to be authorized. In Linux seems to work out of
>the box but in windows I had always had an error like
>
>"Could not impersonate INTRANET\XXXX as authentication token was not
>provided".
>
>The ticket stored in my box for the server I connect to includes the following
>attribute
>
>Ticket Flags -> forwardable renewable pre_authent ok_as_delegate
>
>I have managed to make it work via adding the flag ISC_REQ_DELEGATE to the
>call in spnego_sspi.c (around line 250)
>
> nego->status = s_pSecFn->InitializeSecurityContext(nego->credentials,
> chlg ? nego->context :
> NULL,
> nego->spn,
> ISC_REQ_DELEGATE | ISC_REQ_CONFIDENTIALITY,
>// <== CODE CHANGE added flag ISC_REQ_DELEGATE
> 0, SECURITY_NATIVE_DREP,
> chlg ? &chlg_desc : NULL,
> 0, nego->context,
> &resp_desc, &attrs,
> &expiry);
>
>Now what I wanted to do is to handle the parameter --delegation properly.
>First of all I wound need to see in the security package support DELEGATION.
>Hence I have checked if the
>
>nego->status = s_pSecFn->QuerySecurityPackageInfo((TCHAR *)
>
>TEXT(SP_NAME_NEGOTIATE),
> &SecurityPackage);
>
>unsigned long isc_flags = ISC_REQ_CONFIDENTIALITY; if (SecurityPackage-
>>fCapabilities & SECPKG_FLAG_DELEGATION) {
>
> if (data->set.gssapi_delegation &
>CURLGSSAPI_DELEGATION_POLICY_FLAG)
> {
> isc_flags |= ISC_REQ_DELEGATE;
> }
> else if (data->set.gssapi_delegation & CURLGSSAPI_DELEGATION_FLAG)
> {
> // error not supported ???
> }
> }
>
>
>Of course is not a gssapi_delegation but I assume sspi should mimic the gssapi
>interface/functionality so we could in theory use the same flag.
>
>Question 1: Is there a way to force the delegation using sspi ? or
>CURLGSSAPI_DELEGATION_FLAG is not supported e.g. there is no way to
>force if the Active directory does not allow it?
>
>Question 2: When I Iook at the fCapability flags in the SecurityPackage
>structure for the loaded package (secur32) I have the info below back (which I
>have pretty printed). The SECPKG_FLAG_DELEGATION is false so I am a bit
>puzzled. I can make it work but the library tells me the delegation is not
>supported.
>
>Now my knowledge in here is very limited.
>If I want to reuse the delegation option what flag do I need to check to know
>If this functionality is supported ? If It is GSS COMPATIBLE ?
>
>Thanks for any help you could provide.
>
>Best Regards
>Claudio Rinaldi
>
>Security Package: Negotiate
>Security Package supported flags: 83bb3
>Comment: Microsoft Package Negotiator
>============================================
>
> SUPPORTED [SECPKG_FLAG_INTEGRITY]
> SUPPORTED [SECPKG_FLAG_PRIVACY]
>NOT SUPPORTED [SECPKG_FLAG_TOKEN_ONLY]
>NOT SUPPORTED [SECPKG_FLAG_DATAGRAM]
> SUPPORTED [SECPKG_FLAG_CONNECTION]
> SUPPORTED [SECPKG_FLAG_MULTI_REQUIRED] NOT SUPPORTED
>[SECPKG_FLAG_CLIENT_ONLY]
> SUPPORTED [SECPKG_FLAG_EXTENDED_ERROR]
> SUPPORTED [SECPKG_FLAG_IMPERSONATION]
> SUPPORTED [SECPKG_FLAG_ACCEPT_WIN32_NAME] NOT SUPPORTED
>[SECPKG_FLAG_STREAM]
> SUPPORTED [SECPKG_FLAG_NEGOTIABLE]
> SUPPORTED [SECPKG_FLAG_GSS_COMPATIBLE]
> SUPPORTED [SECPKG_FLAG_LOGON]
>NOT SUPPORTED [SECPKG_FLAG_ASCII_BUFFERS] NOT SUPPORTED
>[SECPKG_FLAG_FRAGMENT] NOT SUPPORTED
>[SECPKG_FLAG_MUTUAL_AUTH]
>
>NOT SUPPORTED [SECPKG_FLAG_DELEGATION]
>
>NOT SUPPORTED [SECPKG_FLAG_READONLY_WITH_CHECKSUM]
> SUPPORTED [SECPKG_FLAG_RESTRICTED_TOKENS] NOT SUPPORTED
>[SECPKG_FLAG_NEGO_EXTENDER] NOT SUPPORTED
>[SECPKG_FLAG_NEGOTIABLE2] NOT SUPPORTED
>[SECPKG_FLAG_APPCONTAINER_PASSTHROUGH]
>NOT SUPPORTED [SECPKG_FLAG_APPCONTAINER_CHECKS]

Hi Everyone,

A couple of month ago I sent the above email but unfortunately I did not get any answer . I have fixed the code locally and it works but it would be good to get this in an official release as a proper fix.

Best regards
Claudio

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Received on 2019-10-10