1/***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at https://curl.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 * RFC4178 Simple and Protected GSS-API Negotiation Mechanism
22 *
23 ***************************************************************************/
24
25#include "curl_setup.h"
26
27#if defined(USE_WINDOWS_SSPI) && defined(USE_SPNEGO)
28
29#include <curl/curl.h>
30
31#include "vauth/vauth.h"
32#include "urldata.h"
33#include "curl_base64.h"
34#include "warnless.h"
35#include "curl_multibyte.h"
36#include "sendf.h"
37#include "strerror.h"
38
39/* The last #include files should be: */
40#include "curl_memory.h"
41#include "memdebug.h"
42
43/*
44 * Curl_auth_is_spnego_supported()
45 *
46 * This is used to evaluate if SPNEGO (Negotiate) is supported.
47 *
48 * Parameters: None
49 *
50 * Returns TRUE if Negotiate is supported by Windows SSPI.
51 */
52bool Curl_auth_is_spnego_supported(void)
53{
54 PSecPkgInfo SecurityPackage;
55 SECURITY_STATUS status;
56
57 /* Query the security package for Negotiate */
58 status = s_pSecFn->QuerySecurityPackageInfo((TCHAR *)
59 TEXT(SP_NAME_NEGOTIATE),
60 &SecurityPackage);
61
62 /* Release the package buffer as it is not required anymore */
63 if(status == SEC_E_OK) {
64 s_pSecFn->FreeContextBuffer(SecurityPackage);
65 }
66
67
68 return (status == SEC_E_OK ? TRUE : FALSE);
69}
70
71/*
72 * Curl_auth_decode_spnego_message()
73 *
74 * This is used to decode an already encoded SPNEGO (Negotiate) challenge
75 * message.
76 *
77 * Parameters:
78 *
79 * data [in] - The session handle.
80 * user [in] - The user name in the format User or Domain\User.
81 * password [in] - The user's password.
82 * service [in] - The service type such as http, smtp, pop or imap.
83 * host [in] - The host name.
84 * chlg64 [in] - The optional base64 encoded challenge message.
85 * nego [in/out] - The Negotiate data struct being used and modified.
86 *
87 * Returns CURLE_OK on success.
88 */
89CURLcode Curl_auth_decode_spnego_message(struct Curl_easy *data,
90 const char *user,
91 const char *password,
92 const char *service,
93 const char *host,
94 const char *chlg64,
95 struct negotiatedata *nego)
96{
97 CURLcode result = CURLE_OK;
98 size_t chlglen = 0;
99 unsigned char *chlg = NULL;
100 PSecPkgInfo SecurityPackage;
101 SecBuffer chlg_buf[2];
102 SecBuffer resp_buf;
103 SecBufferDesc chlg_desc;
104 SecBufferDesc resp_desc;
105 unsigned long attrs;
106 TimeStamp expiry; /* For Windows 9x compatibility of SSPI calls */
107
108#if defined(CURL_DISABLE_VERBOSE_STRINGS)
109 (void) data;
110#endif
111
112 if(nego->context && nego->status == SEC_E_OK) {
113 /* We finished successfully our part of authentication, but server
114 * rejected it (since we're again here). Exit with an error since we
115 * can't invent anything better */
116 Curl_auth_cleanup_spnego(nego);
117 return CURLE_LOGIN_DENIED;
118 }
119
120 if(!nego->spn) {
121 /* Generate our SPN */
122 nego->spn = Curl_auth_build_spn(service, host, NULL);
123 if(!nego->spn)
124 return CURLE_OUT_OF_MEMORY;
125 }
126
127 if(!nego->output_token) {
128 /* Query the security package for Negotiate */
129 nego->status = s_pSecFn->QuerySecurityPackageInfo((TCHAR *)
130 TEXT(SP_NAME_NEGOTIATE),
131 &SecurityPackage);
132 if(nego->status != SEC_E_OK) {
133 failf(data, "SSPI: couldn't get auth info");
134 return CURLE_AUTH_ERROR;
135 }
136
137 nego->token_max = SecurityPackage->cbMaxToken;
138
139 /* Release the package buffer as it is not required anymore */
140 s_pSecFn->FreeContextBuffer(SecurityPackage);
141
142 /* Allocate our output buffer */
143 nego->output_token = malloc(nego->token_max);
144 if(!nego->output_token)
145 return CURLE_OUT_OF_MEMORY;
146 }
147
148 if(!nego->credentials) {
149 /* Do we have credentials to use or are we using single sign-on? */
150 if(user && *user) {
151 /* Populate our identity structure */
152 result = Curl_create_sspi_identity(user, password, &nego->identity);
153 if(result)
154 return result;
155
156 /* Allow proper cleanup of the identity structure */
157 nego->p_identity = &nego->identity;
158 }
159 else
160 /* Use the current Windows user */
161 nego->p_identity = NULL;
162
163 /* Allocate our credentials handle */
164 nego->credentials = calloc(1, sizeof(CredHandle));
165 if(!nego->credentials)
166 return CURLE_OUT_OF_MEMORY;
167
168 /* Acquire our credentials handle */
169 nego->status =
170 s_pSecFn->AcquireCredentialsHandle(NULL,
171 (TCHAR *)TEXT(SP_NAME_NEGOTIATE),
172 SECPKG_CRED_OUTBOUND, NULL,
173 nego->p_identity, NULL, NULL,
174 nego->credentials, &expiry);
175 if(nego->status != SEC_E_OK)
176 return CURLE_AUTH_ERROR;
177
178 /* Allocate our new context handle */
179 nego->context = calloc(1, sizeof(CtxtHandle));
180 if(!nego->context)
181 return CURLE_OUT_OF_MEMORY;
182 }
183
184 if(chlg64 && *chlg64) {
185 /* Decode the base-64 encoded challenge message */
186 if(*chlg64 != '=') {
187 result = Curl_base64_decode(chlg64, &chlg, &chlglen);
188 if(result)
189 return result;
190 }
191
192 /* Ensure we have a valid challenge message */
193 if(!chlg) {
194 infof(data, "SPNEGO handshake failure (empty challenge message)");
195 return CURLE_BAD_CONTENT_ENCODING;
196 }
197
198 /* Setup the challenge "input" security buffer */
199 chlg_desc.ulVersion = SECBUFFER_VERSION;
200 chlg_desc.cBuffers = 1;
201 chlg_desc.pBuffers = &chlg_buf[0];
202 chlg_buf[0].BufferType = SECBUFFER_TOKEN;
203 chlg_buf[0].pvBuffer = chlg;
204 chlg_buf[0].cbBuffer = curlx_uztoul(chlglen);
205
206#ifdef SECPKG_ATTR_ENDPOINT_BINDINGS
207 /* ssl context comes from Schannel.
208 * When extended protection is used in IIS server,
209 * we have to pass a second SecBuffer to the SecBufferDesc
210 * otherwise IIS will not pass the authentication (401 response).
211 * Minimum supported version is Windows 7.
212 * https://docs.microsoft.com/en-us/security-updates
213 * /SecurityAdvisories/2009/973811
214 */
215 if(nego->sslContext) {
216 SEC_CHANNEL_BINDINGS channelBindings;
217 SecPkgContext_Bindings pkgBindings;
218 pkgBindings.Bindings = &channelBindings;
219 nego->status = s_pSecFn->QueryContextAttributes(
220 nego->sslContext,
221 SECPKG_ATTR_ENDPOINT_BINDINGS,
222 &pkgBindings
223 );
224 if(nego->status == SEC_E_OK) {
225 chlg_desc.cBuffers++;
226 chlg_buf[1].BufferType = SECBUFFER_CHANNEL_BINDINGS;
227 chlg_buf[1].cbBuffer = pkgBindings.BindingsLength;
228 chlg_buf[1].pvBuffer = pkgBindings.Bindings;
229 }
230 }
231#endif
232 }
233
234 /* Setup the response "output" security buffer */
235 resp_desc.ulVersion = SECBUFFER_VERSION;
236 resp_desc.cBuffers = 1;
237 resp_desc.pBuffers = &resp_buf;
238 resp_buf.BufferType = SECBUFFER_TOKEN;
239 resp_buf.pvBuffer = nego->output_token;
240 resp_buf.cbBuffer = curlx_uztoul(nego->token_max);
241
242 /* Generate our challenge-response message */
243 nego->status = s_pSecFn->InitializeSecurityContext(nego->credentials,
244 chlg ? nego->context :
245 NULL,
246 nego->spn,
247 ISC_REQ_CONFIDENTIALITY,
248 0, SECURITY_NATIVE_DREP,
249 chlg ? &chlg_desc : NULL,
250 0, nego->context,
251 &resp_desc, &attrs,
252 &expiry);
253
254 /* Free the decoded challenge as it is not required anymore */
255 free(chlg);
256
257 if(GSS_ERROR(nego->status)) {
258 char buffer[STRERROR_LEN];
259 failf(data, "InitializeSecurityContext failed: %s",
260 Curl_sspi_strerror(nego->status, buffer, sizeof(buffer)));
261
262 if(nego->status == (DWORD)SEC_E_INSUFFICIENT_MEMORY)
263 return CURLE_OUT_OF_MEMORY;
264
265 return CURLE_AUTH_ERROR;
266 }
267
268 if(nego->status == SEC_I_COMPLETE_NEEDED ||
269 nego->status == SEC_I_COMPLETE_AND_CONTINUE) {
270 nego->status = s_pSecFn->CompleteAuthToken(nego->context, &resp_desc);
271 if(GSS_ERROR(nego->status)) {
272 char buffer[STRERROR_LEN];
273 failf(data, "CompleteAuthToken failed: %s",
274 Curl_sspi_strerror(nego->status, buffer, sizeof(buffer)));
275
276 if(nego->status == (DWORD)SEC_E_INSUFFICIENT_MEMORY)
277 return CURLE_OUT_OF_MEMORY;
278
279 return CURLE_AUTH_ERROR;
280 }
281 }
282
283 nego->output_token_length = resp_buf.cbBuffer;
284
285 return result;
286}
287
288/*
289 * Curl_auth_create_spnego_message()
290 *
291 * This is used to generate an already encoded SPNEGO (Negotiate) response
292 * message ready for sending to the recipient.
293 *
294 * Parameters:
295 *
296 * data [in] - The session handle.
297 * nego [in/out] - The Negotiate data struct being used and modified.
298 * outptr [in/out] - The address where a pointer to newly allocated memory
299 * holding the result will be stored upon completion.
300 * outlen [out] - The length of the output message.
301 *
302 * Returns CURLE_OK on success.
303 */
304CURLcode Curl_auth_create_spnego_message(struct Curl_easy *data,
305 struct negotiatedata *nego,
306 char **outptr, size_t *outlen)
307{
308 CURLcode result;
309
310 /* Base64 encode the already generated response */
311 result = Curl_base64_encode(data,
312 (const char *) nego->output_token,
313 nego->output_token_length,
314 outptr, outlen);
315
316 if(result)
317 return result;
318
319 if(!*outptr || !*outlen) {
320 free(*outptr);
321 return CURLE_REMOTE_ACCESS_DENIED;
322 }
323
324 return CURLE_OK;
325}
326
327/*
328 * Curl_auth_cleanup_spnego()
329 *
330 * This is used to clean up the SPNEGO (Negotiate) specific data.
331 *
332 * Parameters:
333 *
334 * nego [in/out] - The Negotiate data struct being cleaned up.
335 *
336 */
337void Curl_auth_cleanup_spnego(struct negotiatedata *nego)
338{
339 /* Free our security context */
340 if(nego->context) {
341 s_pSecFn->DeleteSecurityContext(nego->context);
342 free(nego->context);
343 nego->context = NULL;
344 }
345
346 /* Free our credentials handle */
347 if(nego->credentials) {
348 s_pSecFn->FreeCredentialsHandle(nego->credentials);
349 free(nego->credentials);
350 nego->credentials = NULL;
351 }
352
353 /* Free our identity */
354 Curl_sspi_free_identity(nego->p_identity);
355 nego->p_identity = NULL;
356
357 /* Free the SPN and output token */
358 Curl_safefree(nego->spn);
359 Curl_safefree(nego->output_token);
360
361 /* Reset any variables */
362 nego->status = 0;
363 nego->token_max = 0;
364 nego->noauthpersist = FALSE;
365 nego->havenoauthpersist = FALSE;
366 nego->havenegdata = FALSE;
367 nego->havemultiplerequests = FALSE;
368}
369
370#endif /* USE_WINDOWS_SSPI && USE_SPNEGO */
371