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