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(HAVE_GSSAPI) && 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 "curl_gssapi.h"
37 #include "warnless.h"
38 #include "curl_multibyte.h"
39 #include "sendf.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 supported by the GSS-API library.
53 */
Curl_auth_is_spnego_supported(void)54 bool Curl_auth_is_spnego_supported(void)
55 {
56 return TRUE;
57 }
58
59 /*
60 * Curl_auth_decode_spnego_message()
61 *
62 * This is used to decode an already encoded SPNEGO (Negotiate) challenge
63 * message.
64 *
65 * Parameters:
66 *
67 * data [in] - The session handle.
68 * userp [in] - The user name in the format User or Domain\User.
69 * passwdp [in] - The user's password.
70 * service [in] - The service type such as http, smtp, pop or imap.
71 * host [in] - The host name.
72 * chlg64 [in] - The optional base64 encoded challenge message.
73 * nego [in/out] - The Negotiate data struct being used and modified.
74 *
75 * Returns CURLE_OK on success.
76 */
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)77 CURLcode Curl_auth_decode_spnego_message(struct Curl_easy *data,
78 const char *user,
79 const char *password,
80 const char *service,
81 const char *host,
82 const char *chlg64,
83 struct negotiatedata *nego)
84 {
85 CURLcode result = CURLE_OK;
86 size_t chlglen = 0;
87 unsigned char *chlg = NULL;
88 OM_uint32 major_status;
89 OM_uint32 minor_status;
90 OM_uint32 unused_status;
91 gss_buffer_desc spn_token = GSS_C_EMPTY_BUFFER;
92 gss_buffer_desc input_token = GSS_C_EMPTY_BUFFER;
93 gss_buffer_desc output_token = GSS_C_EMPTY_BUFFER;
94
95 (void) user;
96 (void) password;
97
98 if(nego->context && nego->status == GSS_S_COMPLETE) {
99 /* We finished successfully our part of authentication, but server
100 * rejected it (since we're again here). Exit with an error since we
101 * can't invent anything better */
102 Curl_auth_cleanup_spnego(nego);
103 return CURLE_LOGIN_DENIED;
104 }
105
106 if(!nego->spn) {
107 /* Generate our SPN */
108 char *spn = Curl_auth_build_spn(service, NULL, host);
109 if(!spn)
110 return CURLE_OUT_OF_MEMORY;
111
112 /* Populate the SPN structure */
113 spn_token.value = spn;
114 spn_token.length = strlen(spn);
115
116 /* Import the SPN */
117 major_status = gss_import_name(&minor_status, &spn_token,
118 GSS_C_NT_HOSTBASED_SERVICE,
119 &nego->spn);
120 if(GSS_ERROR(major_status)) {
121 Curl_gss_log_error(data, "gss_import_name() failed: ",
122 major_status, minor_status);
123
124 free(spn);
125
126 return CURLE_AUTH_ERROR;
127 }
128
129 free(spn);
130 }
131
132 if(chlg64 && *chlg64) {
133 /* Decode the base-64 encoded challenge message */
134 if(*chlg64 != '=') {
135 result = Curl_base64_decode(chlg64, &chlg, &chlglen);
136 if(result)
137 return result;
138 }
139
140 /* Ensure we have a valid challenge message */
141 if(!chlg) {
142 infof(data, "SPNEGO handshake failure (empty challenge message)");
143 return CURLE_BAD_CONTENT_ENCODING;
144 }
145
146 /* Setup the challenge "input" security buffer */
147 input_token.value = chlg;
148 input_token.length = chlglen;
149 }
150
151 /* Generate our challenge-response message */
152 major_status = Curl_gss_init_sec_context(data,
153 &minor_status,
154 &nego->context,
155 nego->spn,
156 &Curl_spnego_mech_oid,
157 GSS_C_NO_CHANNEL_BINDINGS,
158 &input_token,
159 &output_token,
160 TRUE,
161 NULL);
162
163 /* Free the decoded challenge as it is not required anymore */
164 Curl_safefree(input_token.value);
165
166 nego->status = major_status;
167 if(GSS_ERROR(major_status)) {
168 if(output_token.value)
169 gss_release_buffer(&unused_status, &output_token);
170
171 Curl_gss_log_error(data, "gss_init_sec_context() failed: ",
172 major_status, minor_status);
173
174 return CURLE_AUTH_ERROR;
175 }
176
177 if(!output_token.value || !output_token.length) {
178 if(output_token.value)
179 gss_release_buffer(&unused_status, &output_token);
180
181 return CURLE_AUTH_ERROR;
182 }
183
184 /* Free previous token */
185 if(nego->output_token.length && nego->output_token.value)
186 gss_release_buffer(&unused_status, &nego->output_token);
187
188 nego->output_token = output_token;
189
190 return CURLE_OK;
191 }
192
193 /*
194 * Curl_auth_create_spnego_message()
195 *
196 * This is used to generate an already encoded SPNEGO (Negotiate) response
197 * message ready for sending to the recipient.
198 *
199 * Parameters:
200 *
201 * data [in] - The session handle.
202 * nego [in/out] - The Negotiate data struct being used and modified.
203 * outptr [in/out] - The address where a pointer to newly allocated memory
204 * holding the result will be stored upon completion.
205 * outlen [out] - The length of the output message.
206 *
207 * Returns CURLE_OK on success.
208 */
Curl_auth_create_spnego_message(struct negotiatedata * nego,char ** outptr,size_t * outlen)209 CURLcode Curl_auth_create_spnego_message(struct negotiatedata *nego,
210 char **outptr, size_t *outlen)
211 {
212 CURLcode result;
213 OM_uint32 minor_status;
214
215 /* Base64 encode the already generated response */
216 result = Curl_base64_encode(nego->output_token.value,
217 nego->output_token.length,
218 outptr, outlen);
219
220 if(result) {
221 gss_release_buffer(&minor_status, &nego->output_token);
222 nego->output_token.value = NULL;
223 nego->output_token.length = 0;
224
225 return result;
226 }
227
228 if(!*outptr || !*outlen) {
229 gss_release_buffer(&minor_status, &nego->output_token);
230 nego->output_token.value = NULL;
231 nego->output_token.length = 0;
232
233 return CURLE_REMOTE_ACCESS_DENIED;
234 }
235
236 return CURLE_OK;
237 }
238
239 /*
240 * Curl_auth_cleanup_spnego()
241 *
242 * This is used to clean up the SPNEGO (Negotiate) specific data.
243 *
244 * Parameters:
245 *
246 * nego [in/out] - The Negotiate data struct being cleaned up.
247 *
248 */
Curl_auth_cleanup_spnego(struct negotiatedata * nego)249 void Curl_auth_cleanup_spnego(struct negotiatedata *nego)
250 {
251 OM_uint32 minor_status;
252
253 /* Free our security context */
254 if(nego->context != GSS_C_NO_CONTEXT) {
255 gss_delete_sec_context(&minor_status, &nego->context, GSS_C_NO_BUFFER);
256 nego->context = GSS_C_NO_CONTEXT;
257 }
258
259 /* Free the output token */
260 if(nego->output_token.value) {
261 gss_release_buffer(&minor_status, &nego->output_token);
262 nego->output_token.value = NULL;
263 nego->output_token.length = 0;
264
265 }
266
267 /* Free the SPN */
268 if(nego->spn != GSS_C_NO_NAME) {
269 gss_release_name(&minor_status, &nego->spn);
270 nego->spn = GSS_C_NO_NAME;
271 }
272
273 /* Reset any variables */
274 nego->status = 0;
275 nego->noauthpersist = FALSE;
276 nego->havenoauthpersist = FALSE;
277 nego->havenegdata = FALSE;
278 nego->havemultiplerequests = FALSE;
279 }
280
281 #endif /* HAVE_GSSAPI && USE_SPNEGO */
282