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(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 */
52bool 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 * passdwp     [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 */
75CURLcode 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_spnego_cleanup(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_OUT_OF_MEMORY;
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)\n");
141
142      return CURLE_BAD_CONTENT_ENCODING;
143    }
144
145    /* Setup the challenge "input" security buffer */
146    input_token.value = chlg;
147    input_token.length = chlglen;
148  }
149
150  /* Generate our challenge-response message */
151  major_status = Curl_gss_init_sec_context(data,
152                                           &minor_status,
153                                           &nego->context,
154                                           nego->spn,
155                                           &Curl_spnego_mech_oid,
156                                           GSS_C_NO_CHANNEL_BINDINGS,
157                                           &input_token,
158                                           &output_token,
159                                           TRUE,
160                                           NULL);
161
162  /* Free the decoded challenge as it is not required anymore */
163  Curl_safefree(input_token.value);
164
165  nego->status = major_status;
166  if(GSS_ERROR(major_status)) {
167    if(output_token.value)
168      gss_release_buffer(&unused_status, &output_token);
169
170    Curl_gss_log_error(data, "gss_init_sec_context() failed: ",
171                       major_status, minor_status);
172
173    return CURLE_OUT_OF_MEMORY;
174  }
175
176  if(!output_token.value || !output_token.length) {
177    if(output_token.value)
178      gss_release_buffer(&unused_status, &output_token);
179
180    return CURLE_OUT_OF_MEMORY;
181  }
182
183  nego->output_token = output_token;
184
185  return CURLE_OK;
186}
187
188/*
189 * Curl_auth_create_spnego_message()
190 *
191 * This is used to generate an already encoded SPNEGO (Negotiate) response
192 * message ready for sending to the recipient.
193 *
194 * Parameters:
195 *
196 * data        [in]     - The session handle.
197 * nego        [in/out] - The Negotiate data struct being used and modified.
198 * outptr      [in/out] - The address where a pointer to newly allocated memory
199 *                        holding the result will be stored upon completion.
200 * outlen      [out]    - The length of the output message.
201 *
202 * Returns CURLE_OK on success.
203 */
204CURLcode Curl_auth_create_spnego_message(struct Curl_easy *data,
205                                         struct negotiatedata *nego,
206                                         char **outptr, size_t *outlen)
207{
208  CURLcode result;
209  OM_uint32 minor_status;
210
211  /* Base64 encode the already generated response */
212  result = Curl_base64_encode(data,
213                              nego->output_token.value,
214                              nego->output_token.length,
215                              outptr, outlen);
216
217  if(result) {
218    gss_release_buffer(&minor_status, &nego->output_token);
219    nego->output_token.value = NULL;
220    nego->output_token.length = 0;
221
222    return result;
223  }
224
225  if(!*outptr || !*outlen) {
226    gss_release_buffer(&minor_status, &nego->output_token);
227    nego->output_token.value = NULL;
228    nego->output_token.length = 0;
229
230    return CURLE_REMOTE_ACCESS_DENIED;
231  }
232
233  return CURLE_OK;
234}
235
236/*
237 * Curl_auth_spnego_cleanup()
238 *
239 * This is used to clean up the SPNEGO (Negotiate) specific data.
240 *
241 * Parameters:
242 *
243 * nego     [in/out] - The Negotiate data struct being cleaned up.
244 *
245 */
246void Curl_auth_spnego_cleanup(struct negotiatedata *nego)
247{
248  OM_uint32 minor_status;
249
250  /* Free our security context */
251  if(nego->context != GSS_C_NO_CONTEXT) {
252    gss_delete_sec_context(&minor_status, &nego->context, GSS_C_NO_BUFFER);
253    nego->context = GSS_C_NO_CONTEXT;
254  }
255
256  /* Free the output token */
257  if(nego->output_token.value) {
258    gss_release_buffer(&minor_status, &nego->output_token);
259    nego->output_token.value = NULL;
260    nego->output_token.length = 0;
261
262  }
263
264  /* Free the SPN */
265  if(nego->spn != GSS_C_NO_NAME) {
266    gss_release_name(&minor_status, &nego->spn);
267    nego->spn = GSS_C_NO_NAME;
268  }
269
270  /* Reset any variables */
271  nego->status = 0;
272}
273
274#endif /* HAVE_GSSAPI && USE_SPNEGO */
275