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         DEBUG(3, ("NTLMSSP: Set final flags:\n"));
 148         debug_ntlmssp_flags(gensec_ntlmssp_state->neg_flags);
 149
 150         if (!msrpc_parse(mem_ctx,
 151                          &in, chal_parse_string,
 152                          "NTLMSSP",
 153                          &ntlmssp_command,
 154                          &server_domain,
 155                          &chal_flags,
 156                          &challenge_blob, 8,
 157                          &unkn1, &unkn2,
 158                          &target_info)) {
 159                 DEBUG(1, ("Failed to parse the NTLMSSP Challenge: (#2)\n"));
 160                 dump_data(2, in.data, in.length);
 161                 talloc_free(mem_ctx);
 162                 return NT_STATUS_INVALID_PARAMETER;
 163         }
 164
 165         gensec_ntlmssp_state->server_domain = server_domain;
 166
 167         if (challenge_blob.length != 8) {
 168                 talloc_free(mem_ctx);
 169                 return NT_STATUS_INVALID_PARAMETER;
 170         }
 171
 172         cli_credentials_get_ntlm_username_domain(gensec_security->credentials, mem_ctx,
 173                                                  &user, &domain);
 174
 175         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 176                 flags |= CLI_CRED_NTLM2;
 177         }
 178         if (gensec_ntlmssp_state->use_ntlmv2) {
 179                 flags |= CLI_CRED_NTLMv2_AUTH;
 180         }
 181         if (gensec_ntlmssp_state->use_nt_response) {
 182                 flags |= CLI_CRED_NTLM_AUTH;
 183         }
 184         if (lp_client_lanman_auth()) {
 185                 flags |= CLI_CRED_LANMAN_AUTH;
 186         }
 187
 188         nt_status = cli_credentials_get_ntlm_response(gensec_security->credentials, mem_ctx,
 189                                                       &flags, challenge_blob, target_info,
 190                                                       &lm_response, &nt_response,
 191                                                       &lm_session_key, &session_key);
 192
 193         if (!NT_STATUS_IS_OK(nt_status)) {
 194                 return nt_status;
 195         }
 196
 197         if (!(flags & CLI_CRED_LANMAN_AUTH)) {
 198                 /* LM Key is incompatible... */
 199                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
 200         }
 201
 202         if (!(flags & CLI_CRED_NTLM2)) {
 203                 /* NTLM2 is incompatible... */
 204                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_NTLM2;
 205         }
 206
 207         if ((gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_LM_KEY)
 208             && lp_client_lanman_auth() && lm_session_key.length == 16) {
 209                 DATA_BLOB new_session_key = data_blob_talloc(mem_ctx, NULL, 16);
 210                 if (lm_response.length == 24) {
 211                         SMBsesskeygen_lm_sess_key(lm_session_key.data, lm_response.data,
 212                                                   new_session_key.data);
 213                 } else {
 214                         static const uint8_t zeros[24];
 215                         SMBsesskeygen_lm_sess_key(lm_session_key.data, zeros,
 216                                                   new_session_key.data);
 217                 }
 218                 new_session_key.length = 16;
 219                 session_key = new_session_key;
 220                 dump_data_pw("LM session key\n", session_key.data, session_key.length);
 221         }
 222
 223
 224         /* Key exchange encryptes a new client-generated session key with
 225            the password-derived key */
 226         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
 227                 /* Make up a new session key */
 228                 uint8_t client_session_key[16];
 229                 generate_random_buffer(client_session_key, sizeof(client_session_key));
 230
 231                 /* Encrypt the new session key with the old one */
 232                 encrypted_session_key = data_blob_talloc(gensec_ntlmssp_state,
 233                                                          client_session_key, sizeof(client_session_key));
 234                 dump_data_pw("KEY_EXCH session key:\n", encrypted_session_key.data, encrypted_session_key.length);
 235                 arcfour_crypt(encrypted_session_key.data, session_key.data, encrypted_session_key.length);
 236                 dump_data_pw("KEY_EXCH session key (enc):\n", encrypted_session_key.data, encrypted_session_key.length);
 237
 238                 /* Mark the new session key as the 'real' session key */
 239                 session_key = data_blob_talloc(mem_ctx, client_session_key, sizeof(client_session_key));
 240         }
 241
 242         /* this generates the actual auth packet */
 243         if (!msrpc_gen(mem_ctx,
 244                        out, auth_gen_string,
 245                        "NTLMSSP",
 246                        NTLMSSP_AUTH,
 247                        lm_response.data, lm_response.length,
 248                        nt_response.data, nt_response.length,
 249                        domain,
 250                        user,
 251                        cli_credentials_get_workstation(gensec_security->credentials),
 252                        encrypted_session_key.data, encrypted_session_key.length,
 253                        gensec_ntlmssp_state->neg_flags)) {
 254                 talloc_free(mem_ctx);
 255                 return NT_STATUS_NO_MEMORY;
 256         }
 257
 258         gensec_ntlmssp_state->session_key = session_key;
 259         talloc_steal(gensec_ntlmssp_state, session_key.data);
 260
 261         talloc_steal(out_mem_ctx, out->data);
 262
 263         /* The client might be using 56 or 40 bit weakened keys */
 264         ntlmssp_weaken_keys(gensec_ntlmssp_state);
 265
 266         gensec_ntlmssp_state->chal = challenge_blob;
 267         gensec_ntlmssp_state->lm_resp = lm_response;
 268         talloc_steal(gensec_ntlmssp_state->lm_resp.data, lm_response.data);
 269         gensec_ntlmssp_state->nt_resp = nt_response;
 270         talloc_steal(gensec_ntlmssp_state->nt_resp.data, nt_response.data);
 271
 272         gensec_ntlmssp_state->expected_state = NTLMSSP_DONE;
 273
 274         if (gensec_security->want_features & (GENSEC_FEATURE_SIGN|GENSEC_FEATURE_SEAL)) {
 275                 nt_status = ntlmssp_sign_init(gensec_ntlmssp_state);
 276                 if (!NT_STATUS_IS_OK(nt_status)) {
 277                         DEBUG(1, ("Could not setup NTLMSSP signing/sealing system (error was: %s)\n",
 278                                   nt_errstr(nt_status)));
 279                         talloc_free(mem_ctx);
 280                         return nt_status;
 281                 }
 282         }
 283
 284         talloc_free(mem_ctx);
 285         return NT_STATUS_OK;
 286 }
 287
 288 NTSTATUS gensec_ntlmssp_client_start(struct gensec_security *gensec_security)
 289 {
 290         struct gensec_ntlmssp_state *gensec_ntlmssp_state;
 291         NTSTATUS nt_status;
 292
 293         nt_status = gensec_ntlmssp_start(gensec_security);
 294         NT_STATUS_NOT_OK_RETURN(nt_status);
 295
 296         gensec_ntlmssp_state = gensec_security->private_data;
 297
 298         gensec_ntlmssp_state->role = NTLMSSP_CLIENT;
 299
 300         gensec_ntlmssp_state->get_domain = lp_workgroup;
 301
 302         gensec_ntlmssp_state->unicode = lp_parm_bool(-1, "ntlmssp_client", "unicode", True);
 303
 304         gensec_ntlmssp_state->use_nt_response = lp_parm_bool(-1, "ntlmssp_client", "send_nt_reponse", True);
 305
 306         gensec_ntlmssp_state->allow_lm_key = (lp_client_lanman_auth()
 307                                           && lp_parm_bool(-1, "ntlmssp_client", "allow_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", "keyexchange", True)) {
 322                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_KEY_EXCH;
 323         }
 324
 325         if (lp_parm_bool(-1, "ntlmssp_client", "ntlm2", True)) {
 326                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_NTLM2;
 327         } else {
 328                 /* apparently we can't do ntlmv2 if we don't do ntlm2 */
 329                 gensec_ntlmssp_state->use_ntlmv2 = False;
 330         }
 331
 332         if (gensec_security->want_features & GENSEC_FEATURE_SESSION_KEY) {
 333                 /*
 334                  * We need to set this to allow a later SetPassword
 335                  * via the SAMR pipe to succeed. Strange.... We could
 336                  * also add  NTLMSSP_NEGOTIATE_SEAL here. JRA.
 337                  *
 338                  * Without this, Windows will not create the master key
 339                  * that it thinks is only used for NTLMSSP signing and
 340                  * sealing.  (It is actually pulled out and used directly)
 341                  */
 342                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SIGN;
 343         }
 344         if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
 345                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SIGN;
 346         }
 347         if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
 348                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SEAL;
 349         }
 350
 351         gensec_security->private_data = gensec_ntlmssp_state;
 352
 353         return NT_STATUS_OK;
 354 }
 355