lib/vauth/spnego_gssapi.c

   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  */
  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  * 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  */
  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_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   /* Free previous token */
 184   if(nego->output_token.length && nego->output_token.value)
 185     gss_release_buffer(&unused_status, &nego->output_token);
 186
 187   nego->output_token = output_token;
 188
 189   return CURLE_OK;
 190 }
 191
 192 /*
 193  * Curl_auth_create_spnego_message()
 194  *
 195  * This is used to generate an already encoded SPNEGO (Negotiate) response
 196  * message ready for sending to the recipient.
 197  *
 198  * Parameters:
 199  *
 200  * data        [in]     - The session handle.
 201  * nego        [in/out] - The Negotiate data struct being used and modified.
 202  * outptr      [in/out] - The address where a pointer to newly allocated memory
 203  *                        holding the result will be stored upon completion.
 204  * outlen      [out]    - The length of the output message.
 205  *
 206  * Returns CURLE_OK on success.
 207  */
 208 CURLcode Curl_auth_create_spnego_message(struct Curl_easy *data,
 209                                          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(data,
 217                               nego->output_token.value,
 218                               nego->output_token.length,
 219                               outptr, outlen);
 220
 221   if(result) {
 222     gss_release_buffer(&minor_status, &nego->output_token);
 223     nego->output_token.value = NULL;
 224     nego->output_token.length = 0;
 225
 226     return result;
 227   }
 228
 229   if(!*outptr || !*outlen) {
 230     gss_release_buffer(&minor_status, &nego->output_token);
 231     nego->output_token.value = NULL;
 232     nego->output_token.length = 0;
 233
 234     return CURLE_REMOTE_ACCESS_DENIED;
 235   }
 236
 237   return CURLE_OK;
 238 }
 239
 240 /*
 241  * Curl_auth_spnego_cleanup()
 242  *
 243  * This is used to clean up the SPNEGO (Negotiate) specific data.
 244  *
 245  * Parameters:
 246  *
 247  * nego     [in/out] - The Negotiate data struct being cleaned up.
 248  *
 249  */
 250 void Curl_auth_spnego_cleanup(struct negotiatedata *nego)
 251 {
 252   OM_uint32 minor_status;
 253
 254   /* Free our security context */
 255   if(nego->context != GSS_C_NO_CONTEXT) {
 256     gss_delete_sec_context(&minor_status, &nego->context, GSS_C_NO_BUFFER);
 257     nego->context = GSS_C_NO_CONTEXT;
 258   }
 259
 260   /* Free the output token */
 261   if(nego->output_token.value) {
 262     gss_release_buffer(&minor_status, &nego->output_token);
 263     nego->output_token.value = NULL;
 264     nego->output_token.length = 0;
 265
 266   }
 267
 268   /* Free the SPN */
 269   if(nego->spn != GSS_C_NO_NAME) {
 270     gss_release_name(&minor_status, &nego->spn);
 271     nego->spn = GSS_C_NO_NAME;
 272   }
 273
 274   /* Reset any variables */
 275   nego->status = 0;
 276 }
 277
 278 #endif /* HAVE_GSSAPI && USE_SPNEGO */