spnego_gssapi.c revision d15eaac64ca1a7244824d660ea84e8815a23d058 
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_decode_spnego_message()
45 *
46 * This is used to decode an already encoded SPNEGO (Negotiate) challenge
47 * message.
48 *
49 * Parameters:
50 *
51 * data        [in]     - The session handle.
52 * userp       [in]     - The user name in the format User or Domain\User.
53 * passdwp     [in]     - The user's password.
54 * service     [in]     - The service type such as http, smtp, pop or imap.
55 * host        [in]     - The host name.
56 * chlg64      [in]     - The optional base64 encoded challenge message.
57 * nego        [in/out] - The Negotiate data struct being used and modified.
58 *
59 * Returns CURLE_OK on success.
60 */
61CURLcode Curl_auth_decode_spnego_message(struct SessionHandle *data,
62                                         const char *user,
63                                         const char *password,
64                                         const char *service,
65                                         const char *host,
66                                         const char *chlg64,
67                                         struct negotiatedata *nego)
68{
69  CURLcode result = CURLE_OK;
70  size_t chlglen = 0;
71  unsigned char *chlg = NULL;
72  OM_uint32 major_status;
73  OM_uint32 minor_status;
74  OM_uint32 unused_status;
75  gss_buffer_desc spn_token = GSS_C_EMPTY_BUFFER;
76  gss_buffer_desc input_token = GSS_C_EMPTY_BUFFER;
77  gss_buffer_desc output_token = GSS_C_EMPTY_BUFFER;
78
79  (void) user;
80  (void) password;
81
82  if(nego->context && nego->status == GSS_S_COMPLETE) {
83    /* We finished successfully our part of authentication, but server
84     * rejected it (since we're again here). Exit with an error since we
85     * can't invent anything better */
86    Curl_auth_spnego_cleanup(nego);
87    return CURLE_LOGIN_DENIED;
88  }
89
90  if(!nego->spn) {
91    /* Generate our SPN */
92    char *spn = Curl_auth_build_spn(service, NULL, host);
93    if(!spn)
94      return CURLE_OUT_OF_MEMORY;
95
96    /* Populate the SPN structure */
97    spn_token.value = spn;
98    spn_token.length = strlen(spn);
99
100    /* Import the SPN */
101    major_status = gss_import_name(&minor_status, &spn_token,
102                                   GSS_C_NT_HOSTBASED_SERVICE,
103                                   &nego->spn);
104    if(GSS_ERROR(major_status)) {
105      Curl_gss_log_error(data, "gss_import_name() failed: ",
106                         major_status, minor_status);
107
108      free(spn);
109
110      return CURLE_OUT_OF_MEMORY;
111    }
112
113    free(spn);
114  }
115
116  if(chlg64 && *chlg64) {
117    /* Decode the base-64 encoded challenge message */
118    if(*chlg64 != '=') {
119      result = Curl_base64_decode(chlg64, &chlg, &chlglen);
120      if(result)
121        return result;
122    }
123
124    /* Ensure we have a valid challenge message */
125    if(!chlg) {
126      infof(data, "SPNEGO handshake failure (empty challenge message)\n");
127
128      return CURLE_BAD_CONTENT_ENCODING;
129    }
130
131    /* Setup the challenge "input" security buffer */
132    input_token.value = chlg;
133    input_token.length = chlglen;
134  }
135
136  /* Generate our challenge-response message */
137  major_status = Curl_gss_init_sec_context(data,
138                                           &minor_status,
139                                           &nego->context,
140                                           nego->spn,
141                                           &Curl_spnego_mech_oid,
142                                           GSS_C_NO_CHANNEL_BINDINGS,
143                                           &input_token,
144                                           &output_token,
145                                           TRUE,
146                                           NULL);
147
148  /* Free the decoded challenge as it is not required anymore */
149  Curl_safefree(input_token.value);
150
151  nego->status = major_status;
152  if(GSS_ERROR(major_status)) {
153    if(output_token.value)
154      gss_release_buffer(&unused_status, &output_token);
155
156    Curl_gss_log_error(data, "gss_init_sec_context() failed: ",
157                       major_status, minor_status);
158
159    return CURLE_OUT_OF_MEMORY;
160  }
161
162  if(!output_token.value || !output_token.length) {
163    if(output_token.value)
164      gss_release_buffer(&unused_status, &output_token);
165
166    return CURLE_OUT_OF_MEMORY;
167  }
168
169  nego->output_token = output_token;
170
171  return CURLE_OK;
172}
173
174/*
175 * Curl_auth_create_spnego_message()
176 *
177 * This is used to generate an already encoded SPNEGO (Negotiate) response
178 * message ready for sending to the recipient.
179 *
180 * Parameters:
181 *
182 * data        [in]     - The session handle.
183 * nego        [in/out] - The Negotiate data struct being used and modified.
184 * outptr      [in/out] - The address where a pointer to newly allocated memory
185 *                        holding the result will be stored upon completion.
186 * outlen      [out]    - The length of the output message.
187 *
188 * Returns CURLE_OK on success.
189 */
190CURLcode Curl_auth_create_spnego_message(struct SessionHandle *data,
191                                         struct negotiatedata *nego,
192                                         char **outptr, size_t *outlen)
193{
194  CURLcode result;
195  OM_uint32 minor_status;
196
197  /* Base64 encode the already generated response */
198  result = Curl_base64_encode(data,
199                              nego->output_token.value,
200                              nego->output_token.length,
201                              outptr, outlen);
202
203  if(result) {
204    gss_release_buffer(&minor_status, &nego->output_token);
205    nego->output_token.value = NULL;
206    nego->output_token.length = 0;
207
208    return result;
209  }
210
211  if(!*outptr || !*outlen) {
212    gss_release_buffer(&minor_status, &nego->output_token);
213    nego->output_token.value = NULL;
214    nego->output_token.length = 0;
215
216    return CURLE_REMOTE_ACCESS_DENIED;
217  }
218
219  return CURLE_OK;
220}
221
222/*
223 * Curl_auth_spnego_cleanup()
224 *
225 * This is used to clean up the SPNEGO (Negotiate) specific data.
226 *
227 * Parameters:
228 *
229 * nego     [in/out] - The Negotiate data struct being cleaned up.
230 *
231 */
232void Curl_auth_spnego_cleanup(struct negotiatedata* nego)
233{
234  OM_uint32 minor_status;
235
236  /* Free our security context */
237  if(nego->context != GSS_C_NO_CONTEXT) {
238    gss_delete_sec_context(&minor_status, &nego->context, GSS_C_NO_BUFFER);
239    nego->context = GSS_C_NO_CONTEXT;
240  }
241
242  /* Free the output token */
243  if(nego->output_token.value) {
244    gss_release_buffer(&minor_status, &nego->output_token);
245    nego->output_token.value = NULL;
246    nego->output_token.length = 0;
247
248  }
249
250  /* Free the SPN */
251  if(nego->spn != GSS_C_NO_NAME) {
252    gss_release_name(&minor_status, &nego->spn);
253    nego->spn = GSS_C_NO_NAME;
254  }
255
256  /* Reset any variables */
257  nego->status = 0;
258}
259
260#endif /* HAVE_GSSAPI && USE_SPNEGO */
261