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/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2022, 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(USE_WINDOWS_SSPI) && defined(USE_SPNEGO)
#include <curl/curl.h>
#include "vauth/vauth.h"
#include "urldata.h"
#include "curl_base64.h"
#include "warnless.h"
#include "curl_multibyte.h"
#include "sendf.h"
#include "strerror.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 is supported by Windows SSPI.
*/
bool Curl_auth_is_spnego_supported(void)
{
PSecPkgInfo SecurityPackage;
SECURITY_STATUS status;
/* Query the security package for Negotiate */
status = s_pSecFn->QuerySecurityPackageInfo((TCHAR *)
TEXT(SP_NAME_NEGOTIATE),
&SecurityPackage);
/* Release the package buffer as it is not required anymore */
if(status == SEC_E_OK) {
s_pSecFn->FreeContextBuffer(SecurityPackage);
}
return (status == SEC_E_OK ? TRUE : FALSE);
}
/*
* Curl_auth_decode_spnego_message()
*
* This is used to decode an already encoded SPNEGO (Negotiate) challenge
* message.
*
* Parameters:
*
* data [in] - The session handle.
* user [in] - The user name in the format User or Domain\User.
* password [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;
PSecPkgInfo SecurityPackage;
SecBuffer chlg_buf[2];
SecBuffer resp_buf;
SecBufferDesc chlg_desc;
SecBufferDesc resp_desc;
unsigned long attrs;
TimeStamp expiry; /* For Windows 9x compatibility of SSPI calls */
#if defined(CURL_DISABLE_VERBOSE_STRINGS)
(void) data;
#endif
if(nego->context && nego->status == SEC_E_OK) {
/* 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 */
nego->spn = Curl_auth_build_spn(service, host, NULL);
if(!nego->spn)
return CURLE_OUT_OF_MEMORY;
}
if(!nego->output_token) {
/* Query the security package for Negotiate */
nego->status = s_pSecFn->QuerySecurityPackageInfo((TCHAR *)
TEXT(SP_NAME_NEGOTIATE),
&SecurityPackage);
if(nego->status != SEC_E_OK) {
failf(data, "SSPI: couldn't get auth info");
return CURLE_AUTH_ERROR;
}
nego->token_max = SecurityPackage->cbMaxToken;
/* Release the package buffer as it is not required anymore */
s_pSecFn->FreeContextBuffer(SecurityPackage);
/* Allocate our output buffer */
nego->output_token = malloc(nego->token_max);
if(!nego->output_token)
return CURLE_OUT_OF_MEMORY;
}
if(!nego->credentials) {
/* Do we have credentials to use or are we using single sign-on? */
if(user && *user) {
/* Populate our identity structure */
result = Curl_create_sspi_identity(user, password, &nego->identity);
if(result)
return result;
/* Allow proper cleanup of the identity structure */
nego->p_identity = &nego->identity;
}
else
/* Use the current Windows user */
nego->p_identity = NULL;
/* Allocate our credentials handle */
nego->credentials = calloc(1, sizeof(CredHandle));
if(!nego->credentials)
return CURLE_OUT_OF_MEMORY;
/* Acquire our credentials handle */
nego->status =
s_pSecFn->AcquireCredentialsHandle(NULL,
(TCHAR *)TEXT(SP_NAME_NEGOTIATE),
SECPKG_CRED_OUTBOUND, NULL,
nego->p_identity, NULL, NULL,
nego->credentials, &expiry);
if(nego->status != SEC_E_OK)
return CURLE_AUTH_ERROR;
/* Allocate our new context handle */
nego->context = calloc(1, sizeof(CtxtHandle));
if(!nego->context)
return CURLE_OUT_OF_MEMORY;
}
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)");
return CURLE_BAD_CONTENT_ENCODING;
}
/* Setup the challenge "input" security buffer */
chlg_desc.ulVersion = SECBUFFER_VERSION;
chlg_desc.cBuffers = 1;
chlg_desc.pBuffers = &chlg_buf[0];
chlg_buf[0].BufferType = SECBUFFER_TOKEN;
chlg_buf[0].pvBuffer = chlg;
chlg_buf[0].cbBuffer = curlx_uztoul(chlglen);
#ifdef SECPKG_ATTR_ENDPOINT_BINDINGS
/* ssl context comes from Schannel.
* When extended protection is used in IIS server,
* we have to pass a second SecBuffer to the SecBufferDesc
* otherwise IIS will not pass the authentication (401 response).
* Minimum supported version is Windows 7.
* https://docs.microsoft.com/en-us/security-updates
* /SecurityAdvisories/2009/973811
*/
if(nego->sslContext) {
SEC_CHANNEL_BINDINGS channelBindings;
SecPkgContext_Bindings pkgBindings;
pkgBindings.Bindings = &channelBindings;
nego->status = s_pSecFn->QueryContextAttributes(
nego->sslContext,
SECPKG_ATTR_ENDPOINT_BINDINGS,
&pkgBindings
);
if(nego->status == SEC_E_OK) {
chlg_desc.cBuffers++;
chlg_buf[1].BufferType = SECBUFFER_CHANNEL_BINDINGS;
chlg_buf[1].cbBuffer = pkgBindings.BindingsLength;
chlg_buf[1].pvBuffer = pkgBindings.Bindings;
}
}
#endif
}
/* Setup the response "output" security buffer */
resp_desc.ulVersion = SECBUFFER_VERSION;
resp_desc.cBuffers = 1;
resp_desc.pBuffers = &resp_buf;
resp_buf.BufferType = SECBUFFER_TOKEN;
resp_buf.pvBuffer = nego->output_token;
resp_buf.cbBuffer = curlx_uztoul(nego->token_max);
/* Generate our challenge-response message */
nego->status = s_pSecFn->InitializeSecurityContext(nego->credentials,
chlg ? nego->context :
NULL,
nego->spn,
ISC_REQ_CONFIDENTIALITY,
0, SECURITY_NATIVE_DREP,
chlg ? &chlg_desc : NULL,
0, nego->context,
&resp_desc, &attrs,
&expiry);
/* Free the decoded challenge as it is not required anymore */
free(chlg);
if(GSS_ERROR(nego->status)) {
char buffer[STRERROR_LEN];
failf(data, "InitializeSecurityContext failed: %s",
Curl_sspi_strerror(nego->status, buffer, sizeof(buffer)));
if(nego->status == (DWORD)SEC_E_INSUFFICIENT_MEMORY)
return CURLE_OUT_OF_MEMORY;
return CURLE_AUTH_ERROR;
}
if(nego->status == SEC_I_COMPLETE_NEEDED ||
nego->status == SEC_I_COMPLETE_AND_CONTINUE) {
nego->status = s_pSecFn->CompleteAuthToken(nego->context, &resp_desc);
if(GSS_ERROR(nego->status)) {
char buffer[STRERROR_LEN];
failf(data, "CompleteAuthToken failed: %s",
Curl_sspi_strerror(nego->status, buffer, sizeof(buffer)));
if(nego->status == (DWORD)SEC_E_INSUFFICIENT_MEMORY)
return CURLE_OUT_OF_MEMORY;
return CURLE_AUTH_ERROR;
}
}
nego->output_token_length = resp_buf.cbBuffer;
return result;
}
/*
* 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 negotiatedata *nego,
char **outptr, size_t *outlen)
{
/* Base64 encode the already generated response */
CURLcode result = Curl_base64_encode((const char *) nego->output_token,
nego->output_token_length, outptr,
outlen);
if(!result && (!*outptr || !*outlen)) {
free(*outptr);
result = CURLE_REMOTE_ACCESS_DENIED;
}
return result;
}
/*
* 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)
{
/* Free our security context */
if(nego->context) {
s_pSecFn->DeleteSecurityContext(nego->context);
free(nego->context);
nego->context = NULL;
}
/* Free our credentials handle */
if(nego->credentials) {
s_pSecFn->FreeCredentialsHandle(nego->credentials);
free(nego->credentials);
nego->credentials = NULL;
}
/* Free our identity */
Curl_sspi_free_identity(nego->p_identity);
nego->p_identity = NULL;
/* Free the SPN and output token */
Curl_safefree(nego->spn);
Curl_safefree(nego->output_token);
/* Reset any variables */
nego->status = 0;
nego->token_max = 0;
nego->noauthpersist = FALSE;
nego->havenoauthpersist = FALSE;
nego->havenegdata = FALSE;
nego->havemultiplerequests = FALSE;
}
#endif /* USE_WINDOWS_SSPI && USE_SPNEGO */