xref: /third_party/curl/lib/vauth/spnego_gssapi.c (revision 13498266)
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 */
54bool 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 */
77CURLcode 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 */
209CURLcode 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 */
249void 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