curl/lib/vauth/spnego_gssapi.c
Viktor Szakats d169ad68fa
gssapi: add support for Apple GSS Framework
Add support for the native GSS Framework on Apple targets, which is
Apple's fork of Heimdal. This option allows to drop Apple's deprecated
MIT Kerberos compatibility shim "mit-krb5/1.7-prerelease".

Source code uses different headers, other than that no source changes
are necessary.

You can enable by configuring with:
autotools: `--enable-gssapi-apple`
CMake: `-DCURL_USE_GSSAPI=ON -DCURL_GSS_FLAVOR=Apple`

These options are experimental, and may receive breaking updates till
the GSS backend selection logic settles, for Apple and also for the GNU
and MIT implementation.

Version string:
```
curl 8.21.0-DEV (aarch64-apple-darwin25.4.0) libcurl/8.21.0-DEV
  OpenSSL/3.6.2 zlib/1.2.12 AppleIDN AppleGSS OpenLDAP/2.4.28/Apple
```

Also:
- drop in-source deprecation warning suppressions when using AppleGSS.
- GHA/macos: enable Apple GSS in CI jobs.

Supported by:
iOS 5.0+, iPadOS 5.0+, Mac Catalyst 13.0+, macOS 10.14+, visionOS 1.0+

Ref: https://developer.apple.com/documentation/gss
Ref: #19109

Closes #22052
2026-07-04 01:21:57 +02:00

295 lines
9 KiB
C

/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
* SPDX-License-Identifier: curl
*
* RFC4178 Simple and Protected GSS-API Negotiation Mechanism
*
***************************************************************************/
#include "curl_setup.h"
#if defined(HAVE_GSSAPI) && defined(USE_SPNEGO)
#include "vauth/vauth.h"
#include "curlx/base64.h"
#include "curl_gssapi.h"
#include "curl_trc.h"
#if defined(CURL_HAVE_DIAG) && defined(__APPLE__) && !defined(HAVE_GSSAPPLE)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
#endif
/*
* Curl_auth_is_spnego_supported()
*
* This is used to evaluate if SPNEGO (Negotiate) is supported.
*
* Parameters: None
*
* Returns TRUE if Negotiate supported by the GSS-API library.
*/
bool Curl_auth_is_spnego_supported(void)
{
return TRUE;
}
/*
* Curl_auth_decode_spnego_message()
*
* This is used to decode an already encoded SPNEGO (Negotiate) challenge
* message.
*
* Parameters:
*
* data [in] - The session handle.
* userp [in] - The username in the format User or Domain\User.
* passwdp [in] - The user's password.
* service [in] - The service type such as http, smtp, pop or imap.
* host [in] - The hostname.
* chlg64 [in] - The optional base64 encoded challenge message.
* nego [in/out] - The Negotiate data struct being used and modified.
*
* Returns CURLE_OK on success.
*/
CURLcode Curl_auth_decode_spnego_message(struct Curl_easy *data,
struct Curl_creds *creds,
const char *default_service,
const char *host,
const char *chlg64,
struct negotiatedata *nego)
{
CURLcode result = CURLE_OK;
size_t chlglen = 0;
unsigned char *chlg = NULL;
OM_uint32 major_status;
OM_uint32 minor_status;
OM_uint32 unused_status;
gss_buffer_desc input_token = GSS_C_EMPTY_BUFFER;
gss_buffer_desc output_token = GSS_C_EMPTY_BUFFER;
gss_channel_bindings_t chan_bindings = GSS_C_NO_CHANNEL_BINDINGS;
#ifdef GSS_C_CHANNEL_BOUND_FLAG
struct gss_channel_bindings_struct chan;
#endif
(void)creds;
if(nego->context && nego->status == GSS_S_COMPLETE) {
/* We finished successfully our part of authentication, but server
* rejected it (since we are again here). Exit with an error since we
* cannot invent anything better */
Curl_auth_cleanup_spnego(nego);
return CURLE_LOGIN_DENIED;
}
if(!nego->spn) {
gss_buffer_desc spn_token = GSS_C_EMPTY_BUFFER;
/* Generate our SPN */
const char *service = Curl_creds_has_sasl_service(creds) ?
Curl_creds_sasl_service(creds) : default_service;
char *spn = Curl_auth_build_spn(service, NULL, host);
if(!spn)
return CURLE_OUT_OF_MEMORY;
/* Populate the SPN structure */
spn_token.value = spn;
spn_token.length = strlen(spn);
/* Import the SPN */
major_status = gss_import_name(&minor_status, &spn_token,
GSS_C_NT_HOSTBASED_SERVICE,
&nego->spn);
if(GSS_ERROR(major_status)) {
Curl_gss_log_error(data, "gss_import_name() failed: ",
major_status, minor_status);
curlx_free(spn);
return CURLE_AUTH_ERROR;
}
curlx_free(spn);
}
if(chlg64 && *chlg64) {
/* Decode the base-64 encoded challenge message */
if(*chlg64 != '=') {
result = curlx_base64_decode(chlg64, &chlg, &chlglen);
if(result)
return result;
}
/* Ensure we have a valid challenge message */
if(!chlg) {
infof(data, "SPNEGO handshake failure (empty challenge message)");
return CURLE_BAD_CONTENT_ENCODING;
}
/* Setup the challenge "input" security buffer */
input_token.value = chlg;
input_token.length = chlglen;
}
/* Set channel binding data if available */
#ifdef GSS_C_CHANNEL_BOUND_FLAG
if(curlx_dyn_len(&nego->channel_binding_data)) {
memset(&chan, 0, sizeof(struct gss_channel_bindings_struct));
chan.application_data.length = curlx_dyn_len(&nego->channel_binding_data);
chan.application_data.value = curlx_dyn_ptr(&nego->channel_binding_data);
chan_bindings = &chan;
}
#endif
/* Generate our challenge-response message */
major_status = Curl_gss_init_sec_context(data,
&minor_status,
&nego->context,
nego->spn,
&Curl_spnego_mech_oid,
chan_bindings,
&input_token,
&output_token,
TRUE,
NULL);
/* Free the decoded challenge as it is not required anymore */
curlx_safefree(input_token.value);
nego->status = major_status;
if(GSS_ERROR(major_status)) {
if(output_token.value)
gss_release_buffer(&unused_status, &output_token);
Curl_gss_log_error(data, "gss_init_sec_context() failed: ",
major_status, minor_status);
return CURLE_AUTH_ERROR;
}
if(!output_token.value || !output_token.length) {
if(output_token.value)
gss_release_buffer(&unused_status, &output_token);
return CURLE_AUTH_ERROR;
}
/* Free previous token */
if(nego->output_token.length && nego->output_token.value)
gss_release_buffer(&unused_status, &nego->output_token);
nego->output_token = output_token;
return CURLE_OK;
}
/*
* Curl_auth_create_spnego_message()
*
* This is used to generate an already encoded SPNEGO (Negotiate) response
* message ready for sending to the recipient.
*
* Parameters:
*
* data [in] - The session handle.
* nego [in/out] - The Negotiate data struct being used and modified.
* outptr [in/out] - The address where a pointer to newly allocated memory
* holding the result is stored upon completion.
* outlen [out] - The length of the output message.
*
* Returns CURLE_OK on success.
*/
CURLcode Curl_auth_create_spnego_message(struct negotiatedata *nego,
char **outptr, size_t *outlen)
{
CURLcode result;
OM_uint32 minor_status;
/* Base64 encode the already generated response */
result = curlx_base64_encode(nego->output_token.value,
nego->output_token.length,
outptr, outlen);
if(result) {
gss_release_buffer(&minor_status, &nego->output_token);
nego->output_token.value = NULL;
nego->output_token.length = 0;
return result;
}
if(!*outptr || !*outlen) {
gss_release_buffer(&minor_status, &nego->output_token);
nego->output_token.value = NULL;
nego->output_token.length = 0;
return CURLE_REMOTE_ACCESS_DENIED;
}
return CURLE_OK;
}
/*
* Curl_auth_cleanup_spnego()
*
* This is used to clean up the SPNEGO (Negotiate) specific data.
*
* Parameters:
*
* nego [in/out] - The Negotiate data struct being cleaned up.
*
*/
void Curl_auth_cleanup_spnego(struct negotiatedata *nego)
{
OM_uint32 minor_status;
/* Free our security context */
if(nego->context != GSS_C_NO_CONTEXT) {
Curl_gss_delete_sec_context(&minor_status, &nego->context,
GSS_C_NO_BUFFER);
nego->context = GSS_C_NO_CONTEXT;
}
/* Free the output token */
if(nego->output_token.value) {
gss_release_buffer(&minor_status, &nego->output_token);
nego->output_token.value = NULL;
nego->output_token.length = 0;
}
/* Free the SPN */
if(nego->spn != GSS_C_NO_NAME) {
gss_release_name(&minor_status, &nego->spn);
nego->spn = GSS_C_NO_NAME;
}
/* Reset any variables */
nego->status = 0;
nego->noauthpersist = FALSE;
nego->havenoauthpersist = FALSE;
nego->havenegdata = FALSE;
nego->havemultiplerequests = FALSE;
}
#if defined(CURL_HAVE_DIAG) && defined(__APPLE__) && !defined(HAVE_GSSAPPLE)
#pragma GCC diagnostic pop
#endif
#endif /* HAVE_GSSAPI && USE_SPNEGO */