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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_decode_spnego_message()
44  *
45  * This is used to decode an already encoded SPNEGO (Negotiate) challenge
46  * message.
47  *
48  * Parameters:
49  *
50  * data        [in]     - The session handle.
51  * userp       [in]     - The user name in the format User or Domain\User.
52  * passdwp     [in]     - The user's password.
53  * service     [in]     - The service type such as http, smtp, pop or imap.
54  * host        [in]     - The host name.
55  * chlg64      [in]     - The optional base64 encoded challenge message.
56  * nego        [in/out] - The Negotiate data struct being used and modified.
57  *
58  * Returns CURLE_OK on success.
59  */
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)60 CURLcode Curl_auth_decode_spnego_message(struct Curl_easy *data,
61                                          const char *user,
62                                          const char *password,
63                                          const char *service,
64                                          const char *host,
65                                          const char *chlg64,
66                                          struct negotiatedata *nego)
67 {
68   CURLcode result = CURLE_OK;
69   size_t chlglen = 0;
70   unsigned char *chlg = NULL;
71   PSecPkgInfo SecurityPackage;
72   SecBuffer chlg_buf;
73   SecBuffer resp_buf;
74   SecBufferDesc chlg_desc;
75   SecBufferDesc resp_desc;
76   unsigned long attrs;
77   TimeStamp expiry; /* For Windows 9x compatibility of SSPI calls */
78 
79 #if defined(CURL_DISABLE_VERBOSE_STRINGS)
80   (void) data;
81 #endif
82 
83   if(nego->context && nego->status == SEC_E_OK) {
84     /* We finished successfully our part of authentication, but server
85      * rejected it (since we're again here). Exit with an error since we
86      * can't invent anything better */
87     Curl_auth_spnego_cleanup(nego);
88     return CURLE_LOGIN_DENIED;
89   }
90 
91   if(!nego->spn) {
92     /* Generate our SPN */
93     nego->spn = Curl_auth_build_spn(service, host, NULL);
94     if(!nego->spn)
95       return CURLE_OUT_OF_MEMORY;
96   }
97 
98   if(!nego->output_token) {
99     /* Query the security package for Negotiate */
100     nego->status = s_pSecFn->QuerySecurityPackageInfo((TCHAR *)
101                                                       TEXT(SP_NAME_NEGOTIATE),
102                                                       &SecurityPackage);
103     if(nego->status != SEC_E_OK)
104       return CURLE_NOT_BUILT_IN;
105 
106     nego->token_max = SecurityPackage->cbMaxToken;
107 
108     /* Release the package buffer as it is not required anymore */
109     s_pSecFn->FreeContextBuffer(SecurityPackage);
110 
111     /* Allocate our output buffer */
112     nego->output_token = malloc(nego->token_max);
113     if(!nego->output_token)
114       return CURLE_OUT_OF_MEMORY;
115  }
116 
117   if(!nego->credentials) {
118     /* Do we have credientials to use or are we using single sign-on? */
119     if(user && *user) {
120       /* Populate our identity structure */
121       result = Curl_create_sspi_identity(user, password, &nego->identity);
122       if(result)
123         return result;
124 
125       /* Allow proper cleanup of the identity structure */
126       nego->p_identity = &nego->identity;
127     }
128     else
129       /* Use the current Windows user */
130       nego->p_identity = NULL;
131 
132     /* Allocate our credentials handle */
133     nego->credentials = malloc(sizeof(CredHandle));
134     if(!nego->credentials)
135       return CURLE_OUT_OF_MEMORY;
136 
137     memset(nego->credentials, 0, sizeof(CredHandle));
138 
139     /* Acquire our credentials handle */
140     nego->status =
141       s_pSecFn->AcquireCredentialsHandle(NULL,
142                                          (TCHAR *)TEXT(SP_NAME_NEGOTIATE),
143                                          SECPKG_CRED_OUTBOUND, NULL,
144                                          nego->p_identity, NULL, NULL,
145                                          nego->credentials, &expiry);
146     if(nego->status != SEC_E_OK)
147       return CURLE_LOGIN_DENIED;
148 
149     /* Allocate our new context handle */
150     nego->context = malloc(sizeof(CtxtHandle));
151     if(!nego->context)
152       return CURLE_OUT_OF_MEMORY;
153 
154     memset(nego->context, 0, sizeof(CtxtHandle));
155   }
156 
157   if(chlg64 && *chlg64) {
158     /* Decode the base-64 encoded challenge message */
159     if(*chlg64 != '=') {
160       result = Curl_base64_decode(chlg64, &chlg, &chlglen);
161       if(result)
162         return result;
163     }
164 
165     /* Ensure we have a valid challenge message */
166     if(!chlg) {
167       infof(data, "SPNEGO handshake failure (empty challenge message)\n");
168 
169       return CURLE_BAD_CONTENT_ENCODING;
170     }
171 
172     /* Setup the challenge "input" security buffer */
173     chlg_desc.ulVersion = SECBUFFER_VERSION;
174     chlg_desc.cBuffers  = 1;
175     chlg_desc.pBuffers  = &chlg_buf;
176     chlg_buf.BufferType = SECBUFFER_TOKEN;
177     chlg_buf.pvBuffer   = chlg;
178     chlg_buf.cbBuffer   = curlx_uztoul(chlglen);
179   }
180 
181   /* Setup the response "output" security buffer */
182   resp_desc.ulVersion = SECBUFFER_VERSION;
183   resp_desc.cBuffers  = 1;
184   resp_desc.pBuffers  = &resp_buf;
185   resp_buf.BufferType = SECBUFFER_TOKEN;
186   resp_buf.pvBuffer   = nego->output_token;
187   resp_buf.cbBuffer   = curlx_uztoul(nego->token_max);
188 
189   /* Generate our challenge-response message */
190   nego->status = s_pSecFn->InitializeSecurityContext(nego->credentials,
191                                                      chlg ? nego->context :
192                                                             NULL,
193                                                      nego->spn,
194                                                      ISC_REQ_CONFIDENTIALITY,
195                                                      0, SECURITY_NATIVE_DREP,
196                                                      chlg ? &chlg_desc : NULL,
197                                                      0, nego->context,
198                                                      &resp_desc, &attrs,
199                                                      &expiry);
200 
201   /* Free the decoded challenge as it is not required anymore */
202   free(chlg);
203 
204   if(GSS_ERROR(nego->status)) {
205     return CURLE_OUT_OF_MEMORY;
206   }
207 
208   if(nego->status == SEC_I_COMPLETE_NEEDED ||
209      nego->status == SEC_I_COMPLETE_AND_CONTINUE) {
210     nego->status = s_pSecFn->CompleteAuthToken(nego->context, &resp_desc);
211     if(GSS_ERROR(nego->status)) {
212       return CURLE_RECV_ERROR;
213     }
214   }
215 
216   nego->output_token_length = resp_buf.cbBuffer;
217 
218   return result;
219 }
220 
221 /*
222  * Curl_auth_create_spnego_message()
223  *
224  * This is used to generate an already encoded SPNEGO (Negotiate) response
225  * message ready for sending to the recipient.
226  *
227  * Parameters:
228  *
229  * data        [in]     - The session handle.
230  * nego        [in/out] - The Negotiate data struct being used and modified.
231  * outptr      [in/out] - The address where a pointer to newly allocated memory
232  *                        holding the result will be stored upon completion.
233  * outlen      [out]    - The length of the output message.
234  *
235  * Returns CURLE_OK on success.
236  */
Curl_auth_create_spnego_message(struct Curl_easy * data,struct negotiatedata * nego,char ** outptr,size_t * outlen)237 CURLcode Curl_auth_create_spnego_message(struct Curl_easy *data,
238                                          struct negotiatedata *nego,
239                                          char **outptr, size_t *outlen)
240 {
241   CURLcode result;
242 
243   /* Base64 encode the already generated response */
244   result = Curl_base64_encode(data,
245                               (const char*) nego->output_token,
246                               nego->output_token_length,
247                               outptr, outlen);
248 
249   if(result)
250     return result;
251 
252   if(!*outptr || !*outlen)
253     return CURLE_REMOTE_ACCESS_DENIED;
254 
255   return CURLE_OK;
256 }
257 
258 /*
259  * Curl_auth_spnego_cleanup()
260  *
261  * This is used to clean up the SPNEGO (Negotiate) specific data.
262  *
263  * Parameters:
264  *
265  * nego     [in/out] - The Negotiate data struct being cleaned up.
266  *
267  */
Curl_auth_spnego_cleanup(struct negotiatedata * nego)268 void Curl_auth_spnego_cleanup(struct negotiatedata *nego)
269 {
270   /* Free our security context */
271   if(nego->context) {
272     s_pSecFn->DeleteSecurityContext(nego->context);
273     free(nego->context);
274     nego->context = NULL;
275   }
276 
277   /* Free our credentials handle */
278   if(nego->credentials) {
279     s_pSecFn->FreeCredentialsHandle(nego->credentials);
280     free(nego->credentials);
281     nego->credentials = NULL;
282   }
283 
284   /* Free our identity */
285   Curl_sspi_free_identity(nego->p_identity);
286   nego->p_identity = NULL;
287 
288   /* Free the SPN and output token */
289   Curl_safefree(nego->spn);
290   Curl_safefree(nego->output_token);
291 
292   /* Reset any variables */
293   nego->status = 0;
294   nego->token_max = 0;
295 }
296 
297 #endif /* USE_WINDOWS_SSPI && USE_SPNEGO */
298