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