--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/curl/lib/vauth/krb5_gssapi.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,401 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 2014 - 2019, Steve Holme, <steve_holme@hotmail.com>.
+ * Copyright (C) 2015, 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.
+ *
+ * RFC4752 The Kerberos V5 ("GSSAPI") SASL Mechanism
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+#if defined(HAVE_GSSAPI) && defined(USE_KERBEROS5)
+
+#include <curl/curl.h>
+
+#include "vauth/vauth.h"
+#include "curl_sasl.h"
+#include "urldata.h"
+#include "curl_base64.h"
+#include "curl_gssapi.h"
+#include "sendf.h"
+#include "curl_printf.h"
+
+/* The last #include files should be: */
+#include "curl_memory.h"
+#include "memdebug.h"
+
+/*
+ * Curl_auth_is_gssapi_supported()
+ *
+ * This is used to evaluate if GSSAPI (Kerberos V5) is supported.
+ *
+ * Parameters: None
+ *
+ * Returns TRUE if Kerberos V5 is supported by the GSS-API library.
+ */
+bool Curl_auth_is_gssapi_supported(void)
+{
+  return TRUE;
+}
+
+/*
+ * Curl_auth_create_gssapi_user_message()
+ *
+ * This is used to generate an already encoded GSSAPI (Kerberos V5) user token
+ * message ready for sending to the recipient.
+ *
+ * Parameters:
+ *
+ * data        [in]     - The session handle.
+ * userp       [in]     - The user name.
+ * passwdp     [in]     - The user's password.
+ * service     [in]     - The service type such as http, smtp, pop or imap.
+ * host        [in[     - The host name.
+ * mutual_auth [in]     - Flag specifying whether or not mutual authentication
+ *                        is enabled.
+ * chlg64      [in]     - Pointer to the optional base64 encoded challenge
+ *                        message.
+ * krb5        [in/out] - The Kerberos 5 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_gssapi_user_message(struct Curl_easy *data,
+                                              const char *userp,
+                                              const char *passwdp,
+                                              const char *service,
+                                              const char *host,
+                                              const bool mutual_auth,
+                                              const char *chlg64,
+                                              struct kerberos5data *krb5,
+                                              char **outptr, size_t *outlen)
+{
+  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) userp;
+  (void) passwdp;
+
+  if(!krb5->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, &krb5->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, "GSSAPI 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;
+  }
+
+  major_status = Curl_gss_init_sec_context(data,
+                                           &minor_status,
+                                           &krb5->context,
+                                           krb5->spn,
+                                           &Curl_krb5_mech_oid,
+                                           GSS_C_NO_CHANNEL_BINDINGS,
+                                           &input_token,
+                                           &output_token,
+                                           mutual_auth,
+                                           NULL);
+
+  /* Free the decoded challenge as it is not required anymore */
+  free(input_token.value);
+
+  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) {
+    /* Base64 encode the response */
+    result = Curl_base64_encode(data, (char *) output_token.value,
+                                output_token.length, outptr, outlen);
+
+    gss_release_buffer(&unused_status, &output_token);
+  }
+  else if(mutual_auth) {
+    *outptr = strdup("");
+    if(!*outptr)
+      result = CURLE_OUT_OF_MEMORY;
+  }
+
+  return result;
+}
+
+/*
+ * Curl_auth_create_gssapi_security_message()
+ *
+ * This is used to generate an already encoded GSSAPI (Kerberos V5) security
+ * token message ready for sending to the recipient.
+ *
+ * Parameters:
+ *
+ * data    [in]     - The session handle.
+ * chlg64  [in]     - Pointer to the optional base64 encoded challenge message.
+ * krb5    [in/out] - The Kerberos 5 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_gssapi_security_message(struct Curl_easy *data,
+                                                  const char *chlg64,
+                                                  struct kerberos5data *krb5,
+                                                  char **outptr,
+                                                  size_t *outlen)
+{
+  CURLcode result = CURLE_OK;
+  size_t chlglen = 0;
+  size_t messagelen = 0;
+  unsigned char *chlg = NULL;
+  unsigned char *message = 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;
+  unsigned int indata = 0;
+  unsigned int outdata = 0;
+  gss_qop_t qop = GSS_C_QOP_DEFAULT;
+  unsigned int sec_layer = 0;
+  unsigned int max_size = 0;
+  gss_name_t username = GSS_C_NO_NAME;
+  gss_buffer_desc username_token;
+
+  /* Decode the base-64 encoded input message */
+  if(strlen(chlg64) && *chlg64 != '=') {
+    result = Curl_base64_decode(chlg64, &chlg, &chlglen);
+    if(result)
+      return result;
+  }
+
+  /* Ensure we have a valid challenge message */
+  if(!chlg) {
+    infof(data, "GSSAPI handshake failure (empty security message)\n");
+
+    return CURLE_BAD_CONTENT_ENCODING;
+  }
+
+  /* Get the fully qualified username back from the context */
+  major_status = gss_inquire_context(&minor_status, krb5->context,
+                                     &username, NULL, NULL, NULL, NULL,
+                                     NULL, NULL);
+  if(GSS_ERROR(major_status)) {
+    Curl_gss_log_error(data, "gss_inquire_context() failed: ",
+                       major_status, minor_status);
+
+    free(chlg);
+
+    return CURLE_AUTH_ERROR;
+  }
+
+  /* Convert the username from internal format to a displayable token */
+  major_status = gss_display_name(&minor_status, username,
+                                  &username_token, NULL);
+  if(GSS_ERROR(major_status)) {
+    Curl_gss_log_error(data, "gss_display_name() failed: ",
+                       major_status, minor_status);
+
+    free(chlg);
+
+    return CURLE_AUTH_ERROR;
+  }
+
+  /* Setup the challenge "input" security buffer */
+  input_token.value = chlg;
+  input_token.length = chlglen;
+
+  /* Decrypt the inbound challenge and obtain the qop */
+  major_status = gss_unwrap(&minor_status, krb5->context, &input_token,
+                            &output_token, NULL, &qop);
+  if(GSS_ERROR(major_status)) {
+    Curl_gss_log_error(data, "gss_unwrap() failed: ",
+                       major_status, minor_status);
+
+    gss_release_buffer(&unused_status, &username_token);
+    free(chlg);
+
+    return CURLE_BAD_CONTENT_ENCODING;
+  }
+
+  /* Not 4 octets long so fail as per RFC4752 Section 3.1 */
+  if(output_token.length != 4) {
+    infof(data, "GSSAPI handshake failure (invalid security data)\n");
+
+    gss_release_buffer(&unused_status, &username_token);
+    free(chlg);
+
+    return CURLE_BAD_CONTENT_ENCODING;
+  }
+
+  /* Copy the data out and free the challenge as it is not required anymore */
+  memcpy(&indata, output_token.value, 4);
+  gss_release_buffer(&unused_status, &output_token);
+  free(chlg);
+
+  /* Extract the security layer */
+  sec_layer = indata & 0x000000FF;
+  if(!(sec_layer & GSSAUTH_P_NONE)) {
+    infof(data, "GSSAPI handshake failure (invalid security layer)\n");
+
+    gss_release_buffer(&unused_status, &username_token);
+
+    return CURLE_BAD_CONTENT_ENCODING;
+  }
+
+  /* Extract the maximum message size the server can receive */
+  max_size = ntohl(indata & 0xFFFFFF00);
+  if(max_size > 0) {
+    /* The server has told us it supports a maximum receive buffer, however, as
+       we don't require one unless we are encrypting data, we tell the server
+       our receive buffer is zero. */
+    max_size = 0;
+  }
+
+  /* Allocate our message */
+  messagelen = sizeof(outdata) + username_token.length + 1;
+  message = malloc(messagelen);
+  if(!message) {
+    gss_release_buffer(&unused_status, &username_token);
+
+    return CURLE_OUT_OF_MEMORY;
+  }
+
+  /* Populate the message with the security layer, client supported receive
+     message size and authorization identity including the 0x00 based
+     terminator. Note: Despite RFC4752 Section 3.1 stating "The authorization
+     identity is not terminated with the zero-valued (%x00) octet." it seems
+     necessary to include it. */
+  outdata = htonl(max_size) | sec_layer;
+  memcpy(message, &outdata, sizeof(outdata));
+  memcpy(message + sizeof(outdata), username_token.value,
+         username_token.length);
+  message[messagelen - 1] = '\0';
+
+  /* Free the username token as it is not required anymore */
+  gss_release_buffer(&unused_status, &username_token);
+
+  /* Setup the "authentication data" security buffer */
+  input_token.value = message;
+  input_token.length = messagelen;
+
+  /* Encrypt the data */
+  major_status = gss_wrap(&minor_status, krb5->context, 0,
+                          GSS_C_QOP_DEFAULT, &input_token, NULL,
+                          &output_token);
+  if(GSS_ERROR(major_status)) {
+    Curl_gss_log_error(data, "gss_wrap() failed: ",
+                       major_status, minor_status);
+
+    free(message);
+
+    return CURLE_AUTH_ERROR;
+  }
+
+  /* Base64 encode the response */
+  result = Curl_base64_encode(data, (char *) output_token.value,
+                              output_token.length, outptr, outlen);
+
+  /* Free the output buffer */
+  gss_release_buffer(&unused_status, &output_token);
+
+  /* Free the message buffer */
+  free(message);
+
+  return result;
+}
+
+/*
+ * Curl_auth_cleanup_gssapi()
+ *
+ * This is used to clean up the GSSAPI (Kerberos V5) specific data.
+ *
+ * Parameters:
+ *
+ * krb5     [in/out] - The Kerberos 5 data struct being cleaned up.
+ *
+ */
+void Curl_auth_cleanup_gssapi(struct kerberos5data *krb5)
+{
+  OM_uint32 minor_status;
+
+  /* Free our security context */
+  if(krb5->context != GSS_C_NO_CONTEXT) {
+    gss_delete_sec_context(&minor_status, &krb5->context, GSS_C_NO_BUFFER);
+    krb5->context = GSS_C_NO_CONTEXT;
+  }
+
+  /* Free the SPN */
+  if(krb5->spn != GSS_C_NO_NAME) {
+    gss_release_name(&minor_status, &krb5->spn);
+    krb5->spn = GSS_C_NO_NAME;
+  }
+}
+
+#endif /* HAVE_GSSAPI && USE_KERBEROS5 */