libcli/http/http_auth.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    HTTP library
   5
   6    Copyright (C) 2014 Samuel Cabrero <samuelcabrero@kernevil.me>
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "http.h"
  24 #include "http_internal.h"
  25 #include "lib/util/tevent_ntstatus.h"
  26 #include "lib/param/param.h"
  27 #include "tevent.h"
  28 #include "auth/gensec/gensec.h"
  29 #include "auth/credentials/credentials.h"
  30 #include "lib/util/data_blob.h"
  31
  32 #undef strcasecmp
  33 #undef strncasecmp
  34
  35 /**
  36  * Copy the request headers from src to dst
  37  */
  38 static NTSTATUS http_copy_header(const struct http_request *src,
  39                                  struct http_request *dst)
  40 {
  41         struct http_header *h;
  42
  43         dst->type = src->type;
  44         dst->major = src->major;
  45         dst->minor = src->minor;
  46         dst->uri = talloc_strdup(dst, src->uri);
  47
  48         for (h = src->headers; h != NULL; h = h->next) {
  49                 http_add_header(dst, &dst->headers, h->key, h->value);
  50         }
  51         dst->headers_size = src->headers_size;
  52
  53         return NT_STATUS_OK;
  54 }
  55
  56 /*
  57  * Retrieve the WWW-Authenticate header from server response based on the
  58  * authentication scheme being used.
  59  */
  60 static NTSTATUS http_parse_auth_response(const DATA_BLOB prefix,
  61                                          struct http_request *auth_response,
  62                                          DATA_BLOB *in)
  63 {
  64         struct http_header *h;
  65
  66         for (h = auth_response->headers; h != NULL; h = h->next) {
  67                 int cmp;
  68
  69                 cmp = strcasecmp(h->key, "WWW-Authenticate");
  70                 if (cmp != 0) {
  71                         continue;
  72                 }
  73
  74                 cmp = strncasecmp(h->value,
  75                                   (const char *)prefix.data,
  76                                   prefix.length);
  77                 if (cmp != 0) {
  78                         continue;
  79                 }
  80
  81                 *in = data_blob_string_const(h->value);
  82                 return NT_STATUS_OK;
  83         }
  84
  85         return NT_STATUS_NOT_SUPPORTED;
  86 }
  87
  88 struct http_auth_state {
  89         struct tevent_context *ev;
  90
  91         struct http_conn *http_conn;
  92
  93         enum http_auth_method auth;
  94         DATA_BLOB prefix;
  95
  96         struct gensec_security *gensec_ctx;
  97         NTSTATUS gensec_status;
  98
  99         const struct http_request *original_request;
 100         struct http_request *next_request;
 101         struct http_request *auth_response;
 102 };
 103
 104
 105 static void http_send_auth_request_gensec_done(struct tevent_req *subreq);
 106 static void http_send_auth_request_http_req_done(struct tevent_req *subreq);
 107 static void http_send_auth_request_http_rep_done(struct tevent_req *subreq);
 108
 109 struct tevent_req *http_send_auth_request_send(TALLOC_CTX *mem_ctx,
 110                                                struct tevent_context *ev,
 111                                                struct http_conn *http_conn,
 112                                                const struct http_request *original_request,
 113                                                struct cli_credentials *credentials,
 114                                                struct loadparm_context *lp_ctx,
 115                                                enum http_auth_method auth)
 116 {
 117         struct tevent_req *req = NULL;
 118         struct http_auth_state *state = NULL;
 119         struct tevent_req *subreq = NULL;
 120         DATA_BLOB gensec_in = data_blob_null;
 121         NTSTATUS status;
 122         struct http_header *h = NULL;
 123         const char *mech_name = NULL;
 124
 125         req = tevent_req_create(mem_ctx, &state, struct http_auth_state);
 126         if (req == NULL) {
 127                 return NULL;
 128         }
 129         state->ev = ev;
 130         state->http_conn = http_conn;
 131         state->auth = auth;
 132         state->original_request = original_request;
 133
 134         status = gensec_init();
 135         if (tevent_req_nterror(req, status)) {
 136                 return tevent_req_post(req, ev);
 137         }
 138
 139         status = gensec_client_start(state, &state->gensec_ctx,
 140                                      lpcfg_gensec_settings(state, lp_ctx));
 141         if (tevent_req_nterror(req, status)) {
 142                 return tevent_req_post(req, ev);
 143         }
 144
 145         status = gensec_set_credentials(state->gensec_ctx, credentials);
 146         if (tevent_req_nterror(req, status)) {
 147                 return tevent_req_post(req, ev);
 148         }
 149
 150         for (h = original_request->headers; h != NULL; h = h->next) {
 151                 int cmp;
 152
 153                 cmp = strcasecmp(h->key, "Host");
 154                 if (cmp != 0) {
 155                         continue;
 156                 }
 157
 158                 status = gensec_set_target_service(state->gensec_ctx, "http");
 159                 if (tevent_req_nterror(req, status)) {
 160                         return tevent_req_post(req, ev);
 161                 }
 162
 163                 status = gensec_set_target_hostname(state->gensec_ctx, h->value);
 164                 if (tevent_req_nterror(req, status)) {
 165                         return tevent_req_post(req, ev);
 166                 }
 167                 break;
 168         }
 169
 170         switch (state->auth) {
 171         case HTTP_AUTH_BASIC:
 172                 mech_name = "http_basic";
 173                 state->prefix = data_blob_string_const("Basic");
 174                 break;
 175         case HTTP_AUTH_NTLM:
 176                 mech_name = "http_ntlm";
 177                 state->prefix = data_blob_string_const("NTLM");
 178                 break;
 179         case HTTP_AUTH_NEGOTIATE:
 180                 mech_name = "http_negotiate";
 181                 state->prefix = data_blob_string_const("Negotiate");
 182                 break;
 183         default:
 184                 tevent_req_nterror(req, NT_STATUS_NOT_SUPPORTED);
 185                 return tevent_req_post(req, ev);
 186         }
 187
 188         status = gensec_start_mech_by_name(state->gensec_ctx, mech_name);
 189         if (tevent_req_nterror(req, status)) {
 190                 return tevent_req_post(req, ev);
 191         }
 192
 193         subreq = gensec_update_send(state, state->ev,
 194                                     state->gensec_ctx,
 195                                     gensec_in);
 196         if (tevent_req_nomem(subreq, req)) {
 197                 return tevent_req_post(req, ev);
 198         }
 199         tevent_req_set_callback(subreq, http_send_auth_request_gensec_done, req);
 200
 201         return req;
 202 }
 203
 204 static void http_send_auth_request_gensec_done(struct tevent_req *subreq)
 205 {
 206         struct tevent_req *req =
 207                 tevent_req_callback_data(subreq,
 208                 struct tevent_req);
 209         struct http_auth_state *state =
 210                 tevent_req_data(req,
 211                 struct http_auth_state);
 212         DATA_BLOB gensec_out = data_blob_null;
 213         NTSTATUS status;
 214         int ret;
 215
 216         TALLOC_FREE(state->auth_response);
 217
 218         status = gensec_update_recv(subreq, state, &gensec_out);
 219         TALLOC_FREE(subreq);
 220         state->gensec_status = status;
 221         if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 222                 status = NT_STATUS_OK;
 223         }
 224         if (tevent_req_nterror(req, status)) {
 225                 return;
 226         }
 227
 228         state->next_request = talloc_zero(state, struct http_request);
 229         if (tevent_req_nomem(state->next_request, req)) {
 230                 return;
 231         }
 232
 233         status = http_copy_header(state->original_request, state->next_request);
 234         if (tevent_req_nterror(req, status)) {
 235                 return;
 236         }
 237
 238         if (!NT_STATUS_IS_OK(state->gensec_status)) {
 239                 /*
 240                  * More preprocessing required before we
 241                  * can include the content.
 242                  */
 243                 ret = http_replace_header(state->next_request,
 244                                           &state->next_request->headers,
 245                                           "Content-Length", "0");
 246                 if (ret != 0) {
 247                         tevent_req_oom(req);
 248                         return;
 249                 }
 250         } else {
 251                 state->next_request->body = state->original_request->body;
 252         }
 253
 254         if (gensec_out.length > 0) {
 255                 ret = http_add_header(state->next_request,
 256                                       &state->next_request->headers,
 257                                       "Authorization",
 258                                       (char *)gensec_out.data);
 259                 if (ret != 0) {
 260                         tevent_req_oom(req);
 261                         return;
 262                 }
 263                 data_blob_free(&gensec_out);
 264         }
 265
 266         subreq = http_send_request_send(state, state->ev,
 267                                         state->http_conn,
 268                                         state->next_request);
 269         if (tevent_req_nomem(subreq, req)) {
 270                 return;
 271         }
 272         tevent_req_set_callback(subreq,
 273                                 http_send_auth_request_http_req_done,
 274                                 req);
 275 }
 276
 277 static void http_send_auth_request_http_req_done(struct tevent_req *subreq)
 278 {
 279         struct tevent_req *req =
 280                 tevent_req_callback_data(subreq,
 281                 struct tevent_req);
 282         struct http_auth_state *state =
 283                 tevent_req_data(req,
 284                 struct http_auth_state);
 285         NTSTATUS status;
 286
 287         TALLOC_FREE(state->next_request);
 288
 289         status = http_send_request_recv(subreq);
 290         TALLOC_FREE(subreq);
 291         if (tevent_req_nterror(req, status)) {
 292                 return;
 293         }
 294
 295         /*
 296          * If no more processing required, it is done
 297          *
 298          * The caller will use http_read_response_send/recv
 299          * in order to get the high level response.
 300          */
 301         if (NT_STATUS_IS_OK(state->gensec_status)) {
 302                 tevent_req_done(req);
 303                 return;
 304         }
 305
 306         /*
 307          * If more processing required, read the response from server
 308          *
 309          * We may get an empty RPCH Echo packet from the server
 310          * on the "RPC_OUT_DATA" path. We need to consume this
 311          * from the socket, but for now we just ignore the bytes.
 312          */
 313         subreq = http_read_response_send(state, state->ev,
 314                                          state->http_conn,
 315                                          UINT16_MAX);
 316         if (tevent_req_nomem(subreq, req)) {
 317                 return;
 318         }
 319         tevent_req_set_callback(subreq,
 320                                 http_send_auth_request_http_rep_done,
 321                                 req);
 322 }
 323
 324 static void http_send_auth_request_http_rep_done(struct tevent_req *subreq)
 325 {
 326         struct tevent_req *req =
 327                 tevent_req_callback_data(subreq,
 328                 struct tevent_req);
 329         struct http_auth_state *state =
 330                 tevent_req_data(req,
 331                 struct http_auth_state);
 332         DATA_BLOB gensec_in = data_blob_null;
 333         NTSTATUS status;
 334
 335         status = http_read_response_recv(subreq, state,
 336                                          &state->auth_response);
 337         TALLOC_FREE(subreq);
 338         if (tevent_req_nterror(req, status)) {
 339                 return;
 340         }
 341
 342         /*
 343          * We we asked for up to UINT16_MAX bytes of
 344          * content, we don't expect
 345          * state->auth_response->remaining_content_length
 346          * to be set.
 347          *
 348          * For now we just ignore any bytes in
 349          * state->auth_response->body.
 350          */
 351         if (state->auth_response->remaining_content_length != 0) {
 352                 tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
 353                 return;
 354         }
 355
 356         status = http_parse_auth_response(state->prefix,
 357                                           state->auth_response,
 358                                           &gensec_in);
 359         if (tevent_req_nterror(req, status)) {
 360                 return;
 361         }
 362
 363         subreq = gensec_update_send(state, state->ev,
 364                                     state->gensec_ctx,
 365                                     gensec_in);
 366         if (tevent_req_nomem(subreq, req)) {
 367                 return;
 368         }
 369         tevent_req_set_callback(subreq, http_send_auth_request_gensec_done, req);
 370 }
 371
 372 NTSTATUS http_send_auth_request_recv(struct tevent_req *req)
 373 {
 374         NTSTATUS status;
 375
 376         if (tevent_req_is_nterror(req, &status)) {
 377                 tevent_req_received(req);
 378                 return status;
 379         }
 380         tevent_req_received(req);
 381
 382         return NT_STATUS_OK;
 383 }