source4/winbind/wb_pam_auth.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Authenticate a user
   5
   6    Copyright (C) Volker Lendecke 2005
   7    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 2 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; if not, write to the Free Software
  21    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 */
  23
  24 #include "includes.h"
  25 #include "libcli/composite/composite.h"
  26 #include "winbind/wb_server.h"
  27 #include "smbd/service_task.h"
  28 #include "auth/credentials/credentials.h"
  29 #include "libcli/auth/libcli_auth.h"
  30 #include "librpc/gen_ndr/ndr_netlogon.h"
  31 #include "librpc/gen_ndr/ndr_netlogon_c.h"
  32
  33 /* Oh, there is so much to keep an eye on when authenticating a user.  Oh my! */
  34 struct pam_auth_crap_state {
  35         struct composite_context *ctx;
  36         struct event_context *event_ctx;
  37         uint32_t logon_parameters;
  38         const char *domain_name;
  39         const char *user_name;
  40         char *unix_username;
  41         const char *workstation;
  42         DATA_BLOB chal, nt_resp, lm_resp;
  43
  44         struct creds_CredentialState *creds_state;
  45         struct netr_Authenticator auth, auth2;
  46         struct netr_NetworkInfo ninfo;
  47         struct netr_LogonSamLogon r;
  48
  49         struct netr_UserSessionKey user_session_key;
  50         struct netr_LMSessionKey lm_key;
  51         DATA_BLOB info3;
  52 };
  53
  54 /*
  55  * NTLM authentication.
  56 */
  57
  58 static void pam_auth_crap_recv_domain(struct composite_context *ctx);
  59 static void pam_auth_crap_recv_samlogon(struct rpc_request *req);
  60
  61 struct composite_context *wb_cmd_pam_auth_crap_send(TALLOC_CTX *mem_ctx,
  62                                                     struct wbsrv_service *service,
  63                                                     uint32_t logon_parameters,
  64                                                     const char *domain,
  65                                                     const char *user,
  66                                                     const char *workstation,
  67                                                     DATA_BLOB chal,
  68                                                     DATA_BLOB nt_resp,
  69                                                     DATA_BLOB lm_resp)
  70 {
  71         struct composite_context *result, *ctx;
  72         struct pam_auth_crap_state *state;
  73
  74         result = composite_create(mem_ctx, service->task->event_ctx);
  75         if (result == NULL) goto failed;
  76
  77         state = talloc(result, struct pam_auth_crap_state);
  78         if (state == NULL) goto failed;
  79         state->ctx = result;
  80         result->private_data = state;
  81
  82         state->logon_parameters = logon_parameters;
  83
  84         state->domain_name = talloc_strdup(state, domain);
  85         if (state->domain_name == NULL) goto failed;
  86
  87         state->user_name = talloc_strdup(state, user);
  88         if (state->user_name == NULL) goto failed;
  89
  90         state->unix_username = NULL;
  91
  92         state->workstation = talloc_strdup(state, workstation);
  93         if (state->workstation == NULL) goto failed;
  94
  95         state->chal = data_blob_talloc(state, chal.data, chal.length);
  96         if ((chal.data != NULL) && (state->chal.data == NULL)) goto failed;
  97
  98         state->nt_resp = data_blob_talloc(state, nt_resp.data, nt_resp.length);
  99         if ((nt_resp.data != NULL) &&
 100             (state->nt_resp.data == NULL)) goto failed;
 101
 102         state->lm_resp = data_blob_talloc(state, lm_resp.data, lm_resp.length);
 103         if ((lm_resp.data != NULL) &&
 104             (state->lm_resp.data == NULL)) goto failed;
 105
 106         ctx = wb_sid2domain_send(state, service, service->primary_sid);
 107         if (ctx == NULL) goto failed;
 108
 109         ctx->async.fn = pam_auth_crap_recv_domain;
 110         ctx->async.private_data = state;
 111         return result;
 112
 113  failed:
 114         talloc_free(result);
 115         return NULL;
 116 }
 117
 118 /*
 119     NTLM Authentication
 120
 121     Send of a SamLogon request to authenticate a user.
 122 */
 123 static void pam_auth_crap_recv_domain(struct composite_context *ctx)
 124 {
 125         struct pam_auth_crap_state *state =
 126                 talloc_get_type(ctx->async.private_data,
 127                                 struct pam_auth_crap_state);
 128         struct rpc_request *req;
 129         struct wbsrv_domain *domain;
 130
 131         state->ctx->status = wb_sid2domain_recv(ctx, &domain);
 132         state->creds_state =
 133                 cli_credentials_get_netlogon_creds(domain->schannel_creds);
 134
 135         creds_client_authenticator(state->creds_state, &state->auth);
 136
 137         state->ninfo.identity_info.account_name.string = state->user_name;
 138         state->ninfo.identity_info.domain_name.string =  state->domain_name;
 139         state->ninfo.identity_info.parameter_control = state->logon_parameters;
 140         state->ninfo.identity_info.logon_id_low = 0;
 141         state->ninfo.identity_info.logon_id_high = 0;
 142         state->ninfo.identity_info.workstation.string = state->workstation;
 143
 144         SMB_ASSERT(state->chal.length == sizeof(state->ninfo.challenge));
 145         memcpy(state->ninfo.challenge, state->chal.data,
 146                sizeof(state->ninfo.challenge));
 147
 148         state->ninfo.nt.length = state->nt_resp.length;
 149         state->ninfo.nt.data = state->nt_resp.data;
 150         state->ninfo.lm.length = state->lm_resp.length;
 151         state->ninfo.lm.data = state->lm_resp.data;
 152
 153         state->r.in.server_name = talloc_asprintf(
 154                 state, "\\\\%s", dcerpc_server_name(domain->netlogon_pipe));
 155         if (composite_nomem(state->r.in.server_name, state->ctx)) return;
 156
 157         ZERO_STRUCT(state->auth2);
 158
 159         state->r.in.computer_name =
 160                 cli_credentials_get_workstation(domain->schannel_creds);
 161         state->r.in.credential = &state->auth;
 162         state->r.in.return_authenticator = &state->auth2;
 163         state->r.in.logon_level = 2;
 164         state->r.in.validation_level = 3;
 165         state->r.in.logon.network = &state->ninfo;
 166         state->r.out.return_authenticator = NULL;
 167
 168         req = dcerpc_netr_LogonSamLogon_send(domain->netlogon_pipe, state,
 169                                              &state->r);
 170         composite_continue_rpc(state->ctx, req, pam_auth_crap_recv_samlogon,
 171                                state);
 172 }
 173
 174 /*
 175    NTLM Authentication
 176
 177    Check the SamLogon reply, decrypt and parse out the session keys and the
 178    info3 structure.
 179 */
 180 static void pam_auth_crap_recv_samlogon(struct rpc_request *req)
 181 {
 182         struct pam_auth_crap_state *state =
 183                 talloc_get_type(req->async.private,
 184                                 struct pam_auth_crap_state);
 185         struct netr_SamBaseInfo *base;
 186         DATA_BLOB tmp_blob;
 187
 188         state->ctx->status = dcerpc_ndr_request_recv(req);
 189         if (!composite_is_ok(state->ctx)) return;
 190
 191         if ((state->r.out.return_authenticator == NULL) ||
 192             (!creds_client_check(state->creds_state,
 193                                  &state->r.out.return_authenticator->cred))) {
 194                 DEBUG(0, ("Credentials check failed!\n"));
 195                 composite_error(state->ctx, NT_STATUS_ACCESS_DENIED);
 196                 return;
 197         }
 198
 199         state->ctx->status = state->r.out.result;
 200         if (!composite_is_ok(state->ctx)) return;
 201
 202         /* Decrypt the session keys before we reform the info3, so the
 203          * person on the other end of winbindd pipe doesn't have to.
 204          * They won't have the encryption key anyway */
 205         creds_decrypt_samlogon(state->creds_state,
 206                                state->r.in.validation_level,
 207                                &state->r.out.validation);
 208
 209         state->ctx->status = ndr_push_struct_blob(
 210                 &tmp_blob, state, state->r.out.validation.sam3,
 211                 (ndr_push_flags_fn_t)ndr_push_netr_SamInfo3);
 212         if (!composite_is_ok(state->ctx)) return;
 213
 214         /* The Samba3 protocol is a bit broken (due to non-IDL
 215          * heritage, so for compatability we must add a non-zero 4
 216          * bytes to the info3 */
 217         state->info3 = data_blob_talloc(state, NULL, tmp_blob.length+4);
 218         if (composite_nomem(state->info3.data, state->ctx)) return;
 219
 220         SIVAL(state->info3.data, 0, 1);
 221         memcpy(state->info3.data+4, tmp_blob.data, tmp_blob.length);
 222
 223         /* We actually only ask for level 3, and assume it above, but
 224          * anyway... */
 225
 226         base = NULL;
 227         switch(state->r.in.validation_level) {
 228         case 2:
 229                 base = &state->r.out.validation.sam2->base;
 230                 break;
 231         case 3:
 232                 base = &state->r.out.validation.sam3->base;
 233                 break;
 234         case 6:
 235                 base = &state->r.out.validation.sam6->base;
 236                 break;
 237         }
 238         if (base == NULL) {
 239                 composite_error(state->ctx, NT_STATUS_INTERNAL_ERROR);
 240                 return;
 241         }
 242
 243         state->user_session_key = base->key;
 244         state->lm_key = base->LMSessKey;
 245
 246         /* Give the caller the most accurate username possible.
 247          * Assists where case sensitive comparisons may be done by our
 248          * ntlm_auth callers */
 249         if (base->account_name.string) {
 250                 state->user_name = base->account_name.string;
 251                 talloc_steal(state, base->account_name.string);
 252         }
 253         if (base->domain.string) {
 254                 state->domain_name = base->domain.string;
 255                 talloc_steal(state, base->domain.string);
 256         }
 257
 258         state->unix_username = talloc_asprintf(state, "%s%s%s",
 259                                                state->domain_name,
 260                                                lp_winbind_separator(),
 261                                                state->user_name);
 262         if (composite_nomem(state->unix_username, state->ctx)) return;
 263
 264         composite_done(state->ctx);
 265 }
 266
 267 /* Having received a NTLM authentication reply, parse out the useful
 268  * reply data for the caller */
 269 NTSTATUS wb_cmd_pam_auth_crap_recv(struct composite_context *c,
 270                                    TALLOC_CTX *mem_ctx,
 271                                    DATA_BLOB *info3,
 272                                    struct netr_UserSessionKey *user_session_key,
 273                                    struct netr_LMSessionKey *lm_key,
 274                                    char **unix_username)
 275 {
 276         struct pam_auth_crap_state *state =
 277                 talloc_get_type(c->private_data, struct pam_auth_crap_state);
 278         NTSTATUS status = composite_wait(c);
 279         if (NT_STATUS_IS_OK(status)) {
 280                 info3->length = state->info3.length;
 281                 info3->data = talloc_steal(mem_ctx, state->info3.data);
 282                 *user_session_key = state->user_session_key;
 283                 *lm_key = state->lm_key;
 284                 *unix_username = talloc_steal(mem_ctx, state->unix_username);
 285         }
 286         talloc_free(state);
 287         return status;
 288 }
 289
 290 /* Handle plaintext authentication, by encrypting the password and
 291  * then sending via the NTLM calls */
 292
 293 struct composite_context *wb_cmd_pam_auth_send(TALLOC_CTX *mem_ctx,
 294                                                struct wbsrv_service *service,
 295                                                const char *domain,
 296                                                const char *user,
 297                                                const char *password)
 298 {
 299         struct cli_credentials *credentials;
 300         const char *workstation;
 301         NTSTATUS status;
 302
 303         DATA_BLOB chal, nt_resp, lm_resp, names_blob;
 304         int flags = CLI_CRED_NTLM_AUTH;
 305         if (lp_client_lanman_auth()) {
 306                 flags |= CLI_CRED_LANMAN_AUTH;
 307         }
 308
 309         if (lp_client_ntlmv2_auth()) {
 310                 flags |= CLI_CRED_NTLMv2_AUTH;
 311         }
 312
 313         DEBUG(5, ("wbsrv_samba3_pam_auth called\n"));
 314
 315         credentials = cli_credentials_init(mem_ctx);
 316         if (!credentials) {
 317                 return NULL;
 318         }
 319         cli_credentials_set_conf(credentials);
 320         cli_credentials_set_domain(credentials, domain, CRED_SPECIFIED);
 321         cli_credentials_set_username(credentials, user, CRED_SPECIFIED);
 322
 323         cli_credentials_set_password(credentials, password, CRED_SPECIFIED);
 324
 325         chal = data_blob_talloc(mem_ctx, NULL, 8);
 326         if (!chal.data) {
 327                 return NULL;
 328         }
 329         generate_random_buffer(chal.data, chal.length);
 330         cli_credentials_get_ntlm_username_domain(credentials, mem_ctx,
 331                                                  &user, &domain);
 332         /* for best compatability with multiple vitual netbios names
 333          * on the host, this should be generated from the
 334          * cli_credentials associated with the machine account */
 335         workstation = cli_credentials_get_workstation(credentials);
 336
 337         names_blob = NTLMv2_generate_names_blob(
 338                 mem_ctx,
 339                 cli_credentials_get_workstation(credentials),
 340                 cli_credentials_get_domain(credentials));
 341
 342         status = cli_credentials_get_ntlm_response(
 343                 credentials, mem_ctx, &flags, chal, names_blob,
 344                 &lm_resp, &nt_resp, NULL, NULL);
 345         if (!NT_STATUS_IS_OK(status)) {
 346                 return NULL;
 347         }
 348         return wb_cmd_pam_auth_crap_send(mem_ctx, service,
 349                                          0 /* logon parameters */,
 350                                          domain, user, workstation,
 351                                          chal, nt_resp, lm_resp);
 352 }
 353
 354 NTSTATUS wb_cmd_pam_auth_recv(struct composite_context *c)
 355 {
 356        struct pam_auth_crap_state *state =
 357                talloc_get_type(c->private_data, struct pam_auth_crap_state);
 358        NTSTATUS status = composite_wait(c);
 359        talloc_free(state);
 360        return status;
 361 }