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1 /***************************************************************************
2  *                                  _   _ ____  _
3  *  Project                     ___| | | |  _ \| |
4  *                             / __| | | | |_) | |
5  *                            | (__| |_| |  _ <| |___
6  *                             \___|\___/|_| \_\_____|
7  *
8  * Copyright (C) 1998 - 2016, 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.haxx.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 
38 /* The last #include files should be: */
39 #include "curl_memory.h"
40 #include "memdebug.h"
41 
42 /*
43  * Curl_auth_is_spnego_supported()
44  *
45  * This is used to evaluate if SPNEGO (Negotiate) is supported.
46  *
47  * Parameters: None
48  *
49  * Returns TRUE if Negotiate is supported by Windows SSPI.
50  */
Curl_auth_is_spnego_supported(void)51 bool Curl_auth_is_spnego_supported(void)
52 {
53   PSecPkgInfo SecurityPackage;
54   SECURITY_STATUS status;
55 
56   /* Query the security package for Negotiate */
57   status = s_pSecFn->QuerySecurityPackageInfo((TCHAR *)
58                                               TEXT(SP_NAME_NEGOTIATE),
59                                               &SecurityPackage);
60 
61   return (status == SEC_E_OK ? TRUE : FALSE);
62 }
63 
64 /*
65  * Curl_auth_decode_spnego_message()
66  *
67  * This is used to decode an already encoded SPNEGO (Negotiate) challenge
68  * message.
69  *
70  * Parameters:
71  *
72  * data        [in]     - The session handle.
73  * userp       [in]     - The user name in the format User or Domain\User.
74  * passdwp     [in]     - The user's password.
75  * service     [in]     - The service type such as http, smtp, pop or imap.
76  * host        [in]     - The host name.
77  * chlg64      [in]     - The optional base64 encoded challenge message.
78  * nego        [in/out] - The Negotiate data struct being used and modified.
79  *
80  * Returns CURLE_OK on success.
81  */
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)82 CURLcode Curl_auth_decode_spnego_message(struct Curl_easy *data,
83                                          const char *user,
84                                          const char *password,
85                                          const char *service,
86                                          const char *host,
87                                          const char *chlg64,
88                                          struct negotiatedata *nego)
89 {
90   CURLcode result = CURLE_OK;
91   size_t chlglen = 0;
92   unsigned char *chlg = NULL;
93   PSecPkgInfo SecurityPackage;
94   SecBuffer chlg_buf;
95   SecBuffer resp_buf;
96   SecBufferDesc chlg_desc;
97   SecBufferDesc resp_desc;
98   unsigned long attrs;
99   TimeStamp expiry; /* For Windows 9x compatibility of SSPI calls */
100 
101 #if defined(CURL_DISABLE_VERBOSE_STRINGS)
102   (void) data;
103 #endif
104 
105   if(nego->context && nego->status == SEC_E_OK) {
106     /* We finished successfully our part of authentication, but server
107      * rejected it (since we're again here). Exit with an error since we
108      * can't invent anything better */
109     Curl_auth_spnego_cleanup(nego);
110     return CURLE_LOGIN_DENIED;
111   }
112 
113   if(!nego->spn) {
114     /* Generate our SPN */
115     nego->spn = Curl_auth_build_spn(service, host, NULL);
116     if(!nego->spn)
117       return CURLE_OUT_OF_MEMORY;
118   }
119 
120   if(!nego->output_token) {
121     /* Query the security package for Negotiate */
122     nego->status = s_pSecFn->QuerySecurityPackageInfo((TCHAR *)
123                                                       TEXT(SP_NAME_NEGOTIATE),
124                                                       &SecurityPackage);
125     if(nego->status != SEC_E_OK)
126       return CURLE_NOT_BUILT_IN;
127 
128     nego->token_max = SecurityPackage->cbMaxToken;
129 
130     /* Release the package buffer as it is not required anymore */
131     s_pSecFn->FreeContextBuffer(SecurityPackage);
132 
133     /* Allocate our output buffer */
134     nego->output_token = malloc(nego->token_max);
135     if(!nego->output_token)
136       return CURLE_OUT_OF_MEMORY;
137  }
138 
139   if(!nego->credentials) {
140     /* Do we have credientials to use or are we using single sign-on? */
141     if(user && *user) {
142       /* Populate our identity structure */
143       result = Curl_create_sspi_identity(user, password, &nego->identity);
144       if(result)
145         return result;
146 
147       /* Allow proper cleanup of the identity structure */
148       nego->p_identity = &nego->identity;
149     }
150     else
151       /* Use the current Windows user */
152       nego->p_identity = NULL;
153 
154     /* Allocate our credentials handle */
155     nego->credentials = malloc(sizeof(CredHandle));
156     if(!nego->credentials)
157       return CURLE_OUT_OF_MEMORY;
158 
159     memset(nego->credentials, 0, sizeof(CredHandle));
160 
161     /* Acquire our credentials handle */
162     nego->status =
163       s_pSecFn->AcquireCredentialsHandle(NULL,
164                                          (TCHAR *)TEXT(SP_NAME_NEGOTIATE),
165                                          SECPKG_CRED_OUTBOUND, NULL,
166                                          nego->p_identity, NULL, NULL,
167                                          nego->credentials, &expiry);
168     if(nego->status != SEC_E_OK)
169       return CURLE_LOGIN_DENIED;
170 
171     /* Allocate our new context handle */
172     nego->context = malloc(sizeof(CtxtHandle));
173     if(!nego->context)
174       return CURLE_OUT_OF_MEMORY;
175 
176     memset(nego->context, 0, sizeof(CtxtHandle));
177   }
178 
179   if(chlg64 && *chlg64) {
180     /* Decode the base-64 encoded challenge message */
181     if(*chlg64 != '=') {
182       result = Curl_base64_decode(chlg64, &chlg, &chlglen);
183       if(result)
184         return result;
185     }
186 
187     /* Ensure we have a valid challenge message */
188     if(!chlg) {
189       infof(data, "SPNEGO handshake failure (empty challenge message)\n");
190 
191       return CURLE_BAD_CONTENT_ENCODING;
192     }
193 
194     /* Setup the challenge "input" security buffer */
195     chlg_desc.ulVersion = SECBUFFER_VERSION;
196     chlg_desc.cBuffers  = 1;
197     chlg_desc.pBuffers  = &chlg_buf;
198     chlg_buf.BufferType = SECBUFFER_TOKEN;
199     chlg_buf.pvBuffer   = chlg;
200     chlg_buf.cbBuffer   = curlx_uztoul(chlglen);
201   }
202 
203   /* Setup the response "output" security buffer */
204   resp_desc.ulVersion = SECBUFFER_VERSION;
205   resp_desc.cBuffers  = 1;
206   resp_desc.pBuffers  = &resp_buf;
207   resp_buf.BufferType = SECBUFFER_TOKEN;
208   resp_buf.pvBuffer   = nego->output_token;
209   resp_buf.cbBuffer   = curlx_uztoul(nego->token_max);
210 
211   /* Generate our challenge-response message */
212   nego->status = s_pSecFn->InitializeSecurityContext(nego->credentials,
213                                                      chlg ? nego->context :
214                                                             NULL,
215                                                      nego->spn,
216                                                      ISC_REQ_CONFIDENTIALITY,
217                                                      0, SECURITY_NATIVE_DREP,
218                                                      chlg ? &chlg_desc : NULL,
219                                                      0, nego->context,
220                                                      &resp_desc, &attrs,
221                                                      &expiry);
222 
223   /* Free the decoded challenge as it is not required anymore */
224   free(chlg);
225 
226   if(GSS_ERROR(nego->status)) {
227     return CURLE_OUT_OF_MEMORY;
228   }
229 
230   if(nego->status == SEC_I_COMPLETE_NEEDED ||
231      nego->status == SEC_I_COMPLETE_AND_CONTINUE) {
232     nego->status = s_pSecFn->CompleteAuthToken(nego->context, &resp_desc);
233     if(GSS_ERROR(nego->status)) {
234       return CURLE_RECV_ERROR;
235     }
236   }
237 
238   nego->output_token_length = resp_buf.cbBuffer;
239 
240   return result;
241 }
242 
243 /*
244  * Curl_auth_create_spnego_message()
245  *
246  * This is used to generate an already encoded SPNEGO (Negotiate) response
247  * message ready for sending to the recipient.
248  *
249  * Parameters:
250  *
251  * data        [in]     - The session handle.
252  * nego        [in/out] - The Negotiate data struct being used and modified.
253  * outptr      [in/out] - The address where a pointer to newly allocated memory
254  *                        holding the result will be stored upon completion.
255  * outlen      [out]    - The length of the output message.
256  *
257  * Returns CURLE_OK on success.
258  */
Curl_auth_create_spnego_message(struct Curl_easy * data,struct negotiatedata * nego,char ** outptr,size_t * outlen)259 CURLcode Curl_auth_create_spnego_message(struct Curl_easy *data,
260                                          struct negotiatedata *nego,
261                                          char **outptr, size_t *outlen)
262 {
263   CURLcode result;
264 
265   /* Base64 encode the already generated response */
266   result = Curl_base64_encode(data,
267                               (const char *) nego->output_token,
268                               nego->output_token_length,
269                               outptr, outlen);
270 
271   if(result)
272     return result;
273 
274   if(!*outptr || !*outlen) {
275     free(*outptr);
276     return CURLE_REMOTE_ACCESS_DENIED;
277   }
278 
279   return CURLE_OK;
280 }
281 
282 /*
283  * Curl_auth_spnego_cleanup()
284  *
285  * This is used to clean up the SPNEGO (Negotiate) specific data.
286  *
287  * Parameters:
288  *
289  * nego     [in/out] - The Negotiate data struct being cleaned up.
290  *
291  */
Curl_auth_spnego_cleanup(struct negotiatedata * nego)292 void Curl_auth_spnego_cleanup(struct negotiatedata *nego)
293 {
294   /* Free our security context */
295   if(nego->context) {
296     s_pSecFn->DeleteSecurityContext(nego->context);
297     free(nego->context);
298     nego->context = NULL;
299   }
300 
301   /* Free our credentials handle */
302   if(nego->credentials) {
303     s_pSecFn->FreeCredentialsHandle(nego->credentials);
304     free(nego->credentials);
305     nego->credentials = NULL;
306   }
307 
308   /* Free our identity */
309   Curl_sspi_free_identity(nego->p_identity);
310   nego->p_identity = NULL;
311 
312   /* Free the SPN and output token */
313   Curl_safefree(nego->spn);
314   Curl_safefree(nego->output_token);
315 
316   /* Reset any variables */
317   nego->status = 0;
318   nego->token_max = 0;
319 }
320 
321 #endif /* USE_WINDOWS_SSPI && USE_SPNEGO */
322