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(HAVE_GSSAPI) && 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 "curl_gssapi.h"
35 #include "warnless.h"
36 #include "curl_multibyte.h"
37 #include "sendf.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 supported by the GSS-API library.
51 */
Curl_auth_is_spnego_supported(void)52 bool Curl_auth_is_spnego_supported(void)
53 {
54 return TRUE;
55 }
56
57 /*
58 * Curl_auth_decode_spnego_message()
59 *
60 * This is used to decode an already encoded SPNEGO (Negotiate) challenge
61 * message.
62 *
63 * Parameters:
64 *
65 * data [in] - The session handle.
66 * userp [in] - The user name in the format User or Domain\User.
67 * passwdp [in] - The user's password.
68 * service [in] - The service type such as http, smtp, pop or imap.
69 * host [in] - The host name.
70 * chlg64 [in] - The optional base64 encoded challenge message.
71 * nego [in/out] - The Negotiate data struct being used and modified.
72 *
73 * Returns CURLE_OK on success.
74 */
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)75 CURLcode Curl_auth_decode_spnego_message(struct Curl_easy *data,
76 const char *user,
77 const char *password,
78 const char *service,
79 const char *host,
80 const char *chlg64,
81 struct negotiatedata *nego)
82 {
83 CURLcode result = CURLE_OK;
84 size_t chlglen = 0;
85 unsigned char *chlg = NULL;
86 OM_uint32 major_status;
87 OM_uint32 minor_status;
88 OM_uint32 unused_status;
89 gss_buffer_desc spn_token = GSS_C_EMPTY_BUFFER;
90 gss_buffer_desc input_token = GSS_C_EMPTY_BUFFER;
91 gss_buffer_desc output_token = GSS_C_EMPTY_BUFFER;
92
93 (void) user;
94 (void) password;
95
96 if(nego->context && nego->status == GSS_S_COMPLETE) {
97 /* We finished successfully our part of authentication, but server
98 * rejected it (since we're again here). Exit with an error since we
99 * can't invent anything better */
100 Curl_auth_cleanup_spnego(nego);
101 return CURLE_LOGIN_DENIED;
102 }
103
104 if(!nego->spn) {
105 /* Generate our SPN */
106 char *spn = Curl_auth_build_spn(service, NULL, host);
107 if(!spn)
108 return CURLE_OUT_OF_MEMORY;
109
110 /* Populate the SPN structure */
111 spn_token.value = spn;
112 spn_token.length = strlen(spn);
113
114 /* Import the SPN */
115 major_status = gss_import_name(&minor_status, &spn_token,
116 GSS_C_NT_HOSTBASED_SERVICE,
117 &nego->spn);
118 if(GSS_ERROR(major_status)) {
119 Curl_gss_log_error(data, "gss_import_name() failed: ",
120 major_status, minor_status);
121
122 free(spn);
123
124 return CURLE_AUTH_ERROR;
125 }
126
127 free(spn);
128 }
129
130 if(chlg64 && *chlg64) {
131 /* Decode the base-64 encoded challenge message */
132 if(*chlg64 != '=') {
133 result = Curl_base64_decode(chlg64, &chlg, &chlglen);
134 if(result)
135 return result;
136 }
137
138 /* Ensure we have a valid challenge message */
139 if(!chlg) {
140 infof(data, "SPNEGO handshake failure (empty challenge message)");
141 return CURLE_BAD_CONTENT_ENCODING;
142 }
143
144 /* Setup the challenge "input" security buffer */
145 input_token.value = chlg;
146 input_token.length = chlglen;
147 }
148
149 /* Generate our challenge-response message */
150 major_status = Curl_gss_init_sec_context(data,
151 &minor_status,
152 &nego->context,
153 nego->spn,
154 &Curl_spnego_mech_oid,
155 GSS_C_NO_CHANNEL_BINDINGS,
156 &input_token,
157 &output_token,
158 TRUE,
159 NULL);
160
161 /* Free the decoded challenge as it is not required anymore */
162 Curl_safefree(input_token.value);
163
164 nego->status = major_status;
165 if(GSS_ERROR(major_status)) {
166 if(output_token.value)
167 gss_release_buffer(&unused_status, &output_token);
168
169 Curl_gss_log_error(data, "gss_init_sec_context() failed: ",
170 major_status, minor_status);
171
172 return CURLE_AUTH_ERROR;
173 }
174
175 if(!output_token.value || !output_token.length) {
176 if(output_token.value)
177 gss_release_buffer(&unused_status, &output_token);
178
179 return CURLE_AUTH_ERROR;
180 }
181
182 /* Free previous token */
183 if(nego->output_token.length && nego->output_token.value)
184 gss_release_buffer(&unused_status, &nego->output_token);
185
186 nego->output_token = output_token;
187
188 return CURLE_OK;
189 }
190
191 /*
192 * Curl_auth_create_spnego_message()
193 *
194 * This is used to generate an already encoded SPNEGO (Negotiate) response
195 * message ready for sending to the recipient.
196 *
197 * Parameters:
198 *
199 * data [in] - The session handle.
200 * nego [in/out] - The Negotiate data struct being used and modified.
201 * outptr [in/out] - The address where a pointer to newly allocated memory
202 * holding the result will be stored upon completion.
203 * outlen [out] - The length of the output message.
204 *
205 * Returns CURLE_OK on success.
206 */
Curl_auth_create_spnego_message(struct Curl_easy * data,struct negotiatedata * nego,char ** outptr,size_t * outlen)207 CURLcode Curl_auth_create_spnego_message(struct Curl_easy *data,
208 struct negotiatedata *nego,
209 char **outptr, size_t *outlen)
210 {
211 CURLcode result;
212 OM_uint32 minor_status;
213
214 /* Base64 encode the already generated response */
215 result = Curl_base64_encode(data,
216 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