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/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2020, 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.
*
* 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 */
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