--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/curl/lib/vauth/spnego_gssapi.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,282 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2019, 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.haxx.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.
+ *
+ * RFC4178 Simple and Protected GSS-API Negotiation Mechanism
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+#if defined(HAVE_GSSAPI) && defined(USE_SPNEGO)
+
+#include <curl/curl.h>
+
+#include "vauth/vauth.h"
+#include "urldata.h"
+#include "curl_base64.h"
+#include "curl_gssapi.h"
+#include "warnless.h"
+#include "curl_multibyte.h"
+#include "sendf.h"
+
+/* The last #include files should be: */
+#include "curl_memory.h"
+#include "memdebug.h"
+
+/*
+ * 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 user name 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 host name.
+ * 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,
+                                         const char *user,
+                                         const char *password,
+                                         const char *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 spn_token = GSS_C_EMPTY_BUFFER;
+  gss_buffer_desc input_token = GSS_C_EMPTY_BUFFER;
+  gss_buffer_desc output_token = GSS_C_EMPTY_BUFFER;
+
+  (void) user;
+  (void) password;
+
+  if(nego->context && nego->status == GSS_S_COMPLETE) {
+    /* We finished successfully our part of authentication, but server
+     * rejected it (since we're again here). Exit with an error since we
+     * can't invent anything better */
+    Curl_auth_cleanup_spnego(nego);
+    return CURLE_LOGIN_DENIED;
+  }
+
+  if(!nego->spn) {
+    /* Generate our SPN */
+    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);
+
+      free(spn);
+
+      return CURLE_AUTH_ERROR;
+    }
+
+    free(spn);
+  }
+
+  if(chlg64 && *chlg64) {
+    /* Decode the base-64 encoded challenge message */
+    if(*chlg64 != '=') {
+      result = Curl_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)\n");
+
+      return CURLE_BAD_CONTENT_ENCODING;
+    }
+
+    /* Setup the challenge "input" security buffer */
+    input_token.value = chlg;
+    input_token.length = chlglen;
+  }
+
+  /* Generate our challenge-response message */
+  major_status = Curl_gss_init_sec_context(data,
+                                           &minor_status,
+                                           &nego->context,
+                                           nego->spn,
+                                           &Curl_spnego_mech_oid,
+                                           GSS_C_NO_CHANNEL_BINDINGS,
+                                           &input_token,
+                                           &output_token,
+                                           TRUE,
+                                           NULL);
+
+  /* Free the decoded challenge as it is not required anymore */
+  Curl_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 will be stored upon completion.
+ * outlen      [out]    - The length of the output message.
+ *
+ * Returns CURLE_OK on success.
+ */
+CURLcode Curl_auth_create_spnego_message(struct Curl_easy *data,
+                                         struct negotiatedata *nego,
+                                         char **outptr, size_t *outlen)
+{
+  CURLcode result;
+  OM_uint32 minor_status;
+
+  /* Base64 encode the already generated response */
+  result = Curl_base64_encode(data,
+                              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) {
+    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;
+}
+
+#endif /* HAVE_GSSAPI && USE_SPNEGO */