source4/auth/ntlmssp/ntlmssp_client.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 3.0
   4    handle NLTMSSP, client server side parsing
   5
   6    Copyright (C) Andrew Tridgell      2001
   7    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2001-2005
   8    Copyright (C) Stefan Metzmacher 2005
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 2 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program; if not, write to the Free Software
  22    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23 */
  24
  25 #include "includes.h"
  26 #include "auth/auth.h"
  27 #include "auth/ntlmssp/ntlmssp.h"
  28 #include "lib/crypto/crypto.h"
  29
  30 /*********************************************************************
  31  Client side NTLMSSP
  32 *********************************************************************/
  33
  34 /**
  35  * Next state function for the Initial packet
  36  *
  37  * @param ntlmssp_state NTLMSSP State
  38  * @param out_mem_ctx The DATA_BLOB *out will be allocated on this context
  39  * @param in A NULL data blob (input ignored)
  40  * @param out The initial negotiate request to the server, as an talloc()ed DATA_BLOB, on out_mem_ctx
  41  * @return Errors or NT_STATUS_OK.
  42  */
  43
  44 NTSTATUS ntlmssp_client_initial(struct gensec_security *gensec_security,
  45                                 TALLOC_CTX *out_mem_ctx,
  46                                 DATA_BLOB in, DATA_BLOB *out)
  47 {
  48         struct gensec_ntlmssp_state *gensec_ntlmssp_state = gensec_security->private_data;
  49
  50         if (gensec_ntlmssp_state->unicode) {
  51                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_UNICODE;
  52         } else {
  53                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_OEM;
  54         }
  55
  56         if (gensec_ntlmssp_state->use_ntlmv2) {
  57                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_NTLM2;
  58         }
  59
  60         /* generate the ntlmssp negotiate packet */
  61         msrpc_gen(out_mem_ctx,
  62                   out, "CddAA",
  63                   "NTLMSSP",
  64                   NTLMSSP_NEGOTIATE,
  65                   gensec_ntlmssp_state->neg_flags,
  66                   gensec_ntlmssp_state->get_domain(),
  67                   cli_credentials_get_workstation(gensec_security->credentials));
  68
  69         gensec_ntlmssp_state->expected_state = NTLMSSP_CHALLENGE;
  70
  71         return NT_STATUS_MORE_PROCESSING_REQUIRED;
  72 }
  73
  74 /**
  75  * Next state function for the Challenge Packet.  Generate an auth packet.
  76  *
  77  * @param gensec_security GENSEC state
  78  * @param out_mem_ctx Memory context for *out
  79  * @param in The server challnege, as a DATA_BLOB.  reply.data must be NULL
  80  * @param out The next request (auth packet) to the server, as an allocated DATA_BLOB, on the out_mem_ctx context
  81  * @return Errors or NT_STATUS_OK.
  82  */
  83
  84 NTSTATUS ntlmssp_client_challenge(struct gensec_security *gensec_security,
  85                                   TALLOC_CTX *out_mem_ctx,
  86                                   const DATA_BLOB in, DATA_BLOB *out)
  87 {
  88         struct gensec_ntlmssp_state *gensec_ntlmssp_state = gensec_security->private_data;
  89         uint32_t chal_flags, ntlmssp_command, unkn1, unkn2;
  90         DATA_BLOB server_domain_blob;
  91         DATA_BLOB challenge_blob;
  92         DATA_BLOB target_info = data_blob(NULL, 0);
  93         char *server_domain;
  94         const char *chal_parse_string;
  95         const char *auth_gen_string;
  96         DATA_BLOB lm_response = data_blob(NULL, 0);
  97         DATA_BLOB nt_response = data_blob(NULL, 0);
  98         DATA_BLOB session_key = data_blob(NULL, 0);
  99         DATA_BLOB lm_session_key = data_blob(NULL, 0);
 100         DATA_BLOB encrypted_session_key = data_blob(NULL, 0);
 101         NTSTATUS nt_status;
 102         int flags = 0;
 103         const char *user, *domain;
 104
 105         TALLOC_CTX *mem_ctx = talloc_new(out_mem_ctx);
 106         if (!mem_ctx) {
 107                 return NT_STATUS_NO_MEMORY;
 108         }
 109
 110         if (!msrpc_parse(mem_ctx,
 111                          &in, "CdBd",
 112                          "NTLMSSP",
 113                          &ntlmssp_command,
 114                          &server_domain_blob,
 115                          &chal_flags)) {
 116                 DEBUG(1, ("Failed to parse the NTLMSSP Challenge: (#1)\n"));
 117                 dump_data(2, in.data, in.length);
 118                 talloc_free(mem_ctx);
 119
 120                 return NT_STATUS_INVALID_PARAMETER;
 121         }
 122
 123         data_blob_free(&server_domain_blob);
 124
 125         DEBUG(3, ("Got challenge flags:\n"));
 126         debug_ntlmssp_flags(chal_flags);
 127
 128         ntlmssp_handle_neg_flags(gensec_ntlmssp_state, chal_flags, gensec_ntlmssp_state->allow_lm_key);
 129
 130         if (gensec_ntlmssp_state->unicode) {
 131                 if (chal_flags & NTLMSSP_CHAL_TARGET_INFO) {
 132                         chal_parse_string = "CdUdbddB";
 133                 } else {
 134                         chal_parse_string = "CdUdbdd";
 135                 }
 136                 auth_gen_string = "CdBBUUUBd";
 137         } else {
 138                 if (chal_flags & NTLMSSP_CHAL_TARGET_INFO) {
 139                         chal_parse_string = "CdAdbddB";
 140                 } else {
 141                         chal_parse_string = "CdAdbdd";
 142                 }
 143
 144                 auth_gen_string = "CdBBAAABd";
 145         }
 146
 147         if (!msrpc_parse(mem_ctx,
 148                          &in, chal_parse_string,
 149                          "NTLMSSP",
 150                          &ntlmssp_command,
 151                          &server_domain,
 152                          &chal_flags,
 153                          &challenge_blob, 8,
 154                          &unkn1, &unkn2,
 155                          &target_info)) {
 156                 DEBUG(1, ("Failed to parse the NTLMSSP Challenge: (#2)\n"));
 157                 dump_data(2, in.data, in.length);
 158                 talloc_free(mem_ctx);
 159                 return NT_STATUS_INVALID_PARAMETER;
 160         }
 161
 162         gensec_ntlmssp_state->server_domain = server_domain;
 163
 164         if (challenge_blob.length != 8) {
 165                 talloc_free(mem_ctx);
 166                 return NT_STATUS_INVALID_PARAMETER;
 167         }
 168
 169         cli_credentials_get_ntlm_username_domain(gensec_security->credentials, mem_ctx,
 170                                                  &user, &domain);
 171
 172         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 173                 flags |= CLI_CRED_NTLM2;
 174         }
 175         if (gensec_ntlmssp_state->use_ntlmv2) {
 176                 flags |= CLI_CRED_NTLMv2_AUTH;
 177         }
 178         if (gensec_ntlmssp_state->use_nt_response) {
 179                 flags |= CLI_CRED_NTLM_AUTH;
 180         }
 181         if (lp_client_lanman_auth()) {
 182                 flags |= CLI_CRED_LANMAN_AUTH;
 183         }
 184
 185         nt_status = cli_credentials_get_ntlm_response(gensec_security->credentials, mem_ctx,
 186                                                       &flags, challenge_blob, target_info,
 187                                                       &lm_response, &nt_response,
 188                                                       &lm_session_key, &session_key);
 189
 190         if (!NT_STATUS_IS_OK(nt_status)) {
 191                 return nt_status;
 192         }
 193
 194         if (!(flags & CLI_CRED_LANMAN_AUTH)) {
 195                 /* LM Key is incompatible... */
 196                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
 197         }
 198
 199         if (!(flags & CLI_CRED_NTLM2)) {
 200                 /* NTLM2 is incompatible... */
 201                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_NTLM2;
 202         }
 203
 204         if ((gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_LM_KEY)
 205             && lp_client_lanman_auth() && lm_session_key.length == 16) {
 206                 DATA_BLOB new_session_key = data_blob_talloc(mem_ctx, NULL, 16);
 207                 if (lm_response.length == 24) {
 208                         SMBsesskeygen_lm_sess_key(lm_session_key.data, lm_response.data,
 209                                                   new_session_key.data);
 210                 } else {
 211                         static const uint8_t zeros[24];
 212                         SMBsesskeygen_lm_sess_key(lm_session_key.data, zeros,
 213                                                   new_session_key.data);
 214                 }
 215                 session_key = new_session_key;
 216                 dump_data_pw("LM session key\n", session_key.data, session_key.length);
 217         }
 218
 219
 220         /* Key exchange encryptes a new client-generated session key with
 221            the password-derived key */
 222         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
 223                 /* Make up a new session key */
 224                 uint8_t client_session_key[16];
 225                 generate_random_buffer(client_session_key, sizeof(client_session_key));
 226
 227                 /* Encrypt the new session key with the old one */
 228                 encrypted_session_key = data_blob_talloc(gensec_ntlmssp_state,
 229                                                          client_session_key, sizeof(client_session_key));
 230                 dump_data_pw("KEY_EXCH session key:\n", encrypted_session_key.data, encrypted_session_key.length);
 231                 arcfour_crypt(encrypted_session_key.data, session_key.data, encrypted_session_key.length);
 232                 dump_data_pw("KEY_EXCH session key (enc):\n", encrypted_session_key.data, encrypted_session_key.length);
 233
 234                 /* Mark the new session key as the 'real' session key */
 235                 session_key = data_blob_talloc(mem_ctx, client_session_key, sizeof(client_session_key));
 236         }
 237
 238         DEBUG(3, ("NTLMSSP: Set final flags:\n"));
 239         debug_ntlmssp_flags(gensec_ntlmssp_state->neg_flags);
 240
 241         /* this generates the actual auth packet */
 242         if (!msrpc_gen(mem_ctx,
 243                        out, auth_gen_string,
 244                        "NTLMSSP",
 245                        NTLMSSP_AUTH,
 246                        lm_response.data, lm_response.length,
 247                        nt_response.data, nt_response.length,
 248                        domain,
 249                        user,
 250                        cli_credentials_get_workstation(gensec_security->credentials),
 251                        encrypted_session_key.data, encrypted_session_key.length,
 252                        gensec_ntlmssp_state->neg_flags)) {
 253                 talloc_free(mem_ctx);
 254                 return NT_STATUS_NO_MEMORY;
 255         }
 256
 257         gensec_ntlmssp_state->session_key = session_key;
 258         talloc_steal(gensec_ntlmssp_state, session_key.data);
 259
 260         talloc_steal(out_mem_ctx, out->data);
 261
 262         /* The client might be using 56 or 40 bit weakened keys */
 263         ntlmssp_weaken_keys(gensec_ntlmssp_state);
 264
 265         gensec_ntlmssp_state->chal = challenge_blob;
 266         gensec_ntlmssp_state->lm_resp = lm_response;
 267         talloc_steal(gensec_ntlmssp_state->lm_resp.data, lm_response.data);
 268         gensec_ntlmssp_state->nt_resp = nt_response;
 269         talloc_steal(gensec_ntlmssp_state->nt_resp.data, nt_response.data);
 270
 271         gensec_ntlmssp_state->expected_state = NTLMSSP_DONE;
 272
 273         if (gensec_security->want_features & (GENSEC_FEATURE_SIGN|GENSEC_FEATURE_SEAL)) {
 274                 nt_status = ntlmssp_sign_init(gensec_ntlmssp_state);
 275                 if (!NT_STATUS_IS_OK(nt_status)) {
 276                         DEBUG(1, ("Could not setup NTLMSSP signing/sealing system (error was: %s)\n",
 277                                   nt_errstr(nt_status)));
 278                         talloc_free(mem_ctx);
 279                         return nt_status;
 280                 }
 281         }
 282
 283         talloc_free(mem_ctx);
 284         return NT_STATUS_OK;
 285 }
 286
 287 NTSTATUS gensec_ntlmssp_client_start(struct gensec_security *gensec_security)
 288 {
 289         struct gensec_ntlmssp_state *gensec_ntlmssp_state;
 290         NTSTATUS nt_status;
 291
 292         nt_status = gensec_ntlmssp_start(gensec_security);
 293         NT_STATUS_NOT_OK_RETURN(nt_status);
 294
 295         gensec_ntlmssp_state = gensec_security->private_data;
 296
 297         gensec_ntlmssp_state->role = NTLMSSP_CLIENT;
 298
 299         gensec_ntlmssp_state->get_domain = lp_workgroup;
 300
 301         gensec_ntlmssp_state->unicode = lp_parm_bool(-1, "ntlmssp_client", "unicode", True);
 302
 303         gensec_ntlmssp_state->use_nt_response = lp_parm_bool(-1, "ntlmssp_client", "send_nt_reponse", True);
 304
 305         gensec_ntlmssp_state->allow_lm_key = (lp_client_lanman_auth()
 306                                               && (lp_parm_bool(-1, "ntlmssp_client", "allow_lm_key", False)
 307                                                   || lp_parm_bool(-1, "ntlmssp_client", "lm_key", False)));
 308
 309         gensec_ntlmssp_state->use_ntlmv2 = lp_client_ntlmv2_auth();
 310
 311         gensec_ntlmssp_state->expected_state = NTLMSSP_INITIAL;
 312
 313         gensec_ntlmssp_state->neg_flags =
 314                 NTLMSSP_NEGOTIATE_NTLM |
 315                 NTLMSSP_REQUEST_TARGET;
 316
 317         if (lp_parm_bool(-1, "ntlmssp_client", "128bit", True)) {
 318                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_128;
 319         }
 320
 321         if (lp_parm_bool(-1, "ntlmssp_client", "56bit", False)) {
 322                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_56;
 323         }
 324
 325         if (lp_parm_bool(-1, "ntlmssp_client", "lm_key", False)) {
 326                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_LM_KEY;
 327         }
 328
 329         if (lp_parm_bool(-1, "ntlmssp_client", "keyexchange", True)) {
 330                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_KEY_EXCH;
 331         }
 332
 333         if (lp_parm_bool(-1, "ntlmssp_client", "ntlm2", True)) {
 334                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_NTLM2;
 335         } else {
 336                 /* apparently we can't do ntlmv2 if we don't do ntlm2 */
 337                 gensec_ntlmssp_state->use_ntlmv2 = False;
 338         }
 339
 340         if (gensec_security->want_features & GENSEC_FEATURE_SESSION_KEY) {
 341                 /*
 342                  * We need to set this to allow a later SetPassword
 343                  * via the SAMR pipe to succeed. Strange.... We could
 344                  * also add  NTLMSSP_NEGOTIATE_SEAL here. JRA.
 345                  *
 346                  * Without this, Windows will not create the master key
 347                  * that it thinks is only used for NTLMSSP signing and
 348                  * sealing.  (It is actually pulled out and used directly)
 349                  */
 350                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SIGN;
 351         }
 352         if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
 353                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SIGN;
 354         }
 355         if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
 356                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SEAL;
 357         }
 358
 359         gensec_security->private_data = gensec_ntlmssp_state;
 360
 361         return NT_STATUS_OK;
 362 }
 363