source/libsmb/smbencrypt.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    SMB parameters and setup
   4    Copyright (C) Andrew Tridgell 1992-1998
   5    Modified by Jeremy Allison 1995.
   6    Copyright (C) Jeremy Allison 1995-2000.
   7    Copyright (C) Luke Kennethc Casson Leighton 1996-2000.
   8    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2002-2003
   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 "byteorder.h"
  27
  28 /*
  29    This implements the X/Open SMB password encryption
  30    It takes a password ('unix' string), a 8 byte "crypt key"
  31    and puts 24 bytes of encrypted password into p24 */
  32 void SMBencrypt(const char *passwd, const uchar *c8, uchar p24[24])
  33 {
  34         uchar p21[21];
  35
  36         memset(p21,'\0',21);
  37         E_deshash(passwd, p21);
  38
  39         SMBOWFencrypt(p21, c8, p24);
  40
  41 #ifdef DEBUG_PASSWORD
  42         DEBUG(100,("SMBencrypt: lm#, challenge, response\n"));
  43         dump_data(100, (char *)p21, 16);
  44         dump_data(100, (const char *)c8, 8);
  45         dump_data(100, (char *)p24, 24);
  46 #endif
  47 }
  48
  49 /**
  50  * Creates the MD4 Hash of the users password in NT UNICODE.
  51  * @param passwd password in 'unix' charset.
  52  * @param p16 return password hashed with md4, caller allocated 16 byte buffer
  53  */
  54
  55 void E_md4hash(const char *passwd, uchar p16[16])
  56 {
  57         int len;
  58         smb_ucs2_t wpwd[129];
  59
  60         /* Password must be converted to NT unicode - null terminated. */
  61         push_ucs2(NULL, wpwd, (const char *)passwd, 256, STR_UNICODE|STR_NOALIGN|STR_TERMINATE);
  62         /* Calculate length in bytes */
  63         len = strlen_w(wpwd) * sizeof(int16);
  64
  65         mdfour(p16, (unsigned char *)wpwd, len);
  66         ZERO_STRUCT(wpwd);
  67 }
  68
  69 /**
  70  * Creates the DES forward-only Hash of the users password in DOS ASCII charset
  71  * @param passwd password in 'unix' charset.
  72  * @param p16 return password hashed with DES, caller allocated 16 byte buffer
  73  */
  74
  75 void E_deshash(const char *passwd, uchar p16[16])
  76 {
  77         fstring dospwd;
  78         ZERO_STRUCT(dospwd);
  79         ZERO_STRUCTP(p16);
  80
  81         /* Password must be converted to DOS charset - null terminated, uppercase. */
  82         push_ascii(dospwd, (const char *)passwd, sizeof(dospwd), STR_UPPER|STR_TERMINATE);
  83
  84         /* Only the fisrt 14 chars are considered, password need not be null terminated. */
  85         E_P16(dospwd, p16);
  86
  87         ZERO_STRUCT(dospwd);
  88 }
  89
  90 /**
  91  * Creates the MD4 and DES (LM) Hash of the users password.
  92  * MD4 is of the NT Unicode, DES is of the DOS UPPERCASE password.
  93  * @param passwd password in 'unix' charset.
  94  * @param nt_p16 return password hashed with md4, caller allocated 16 byte buffer
  95  * @param p16 return password hashed with des, caller allocated 16 byte buffer
  96  */
  97
  98 /* Does both the NT and LM owfs of a user's password */
  99 void nt_lm_owf_gen(const char *pwd, uchar nt_p16[16], uchar p16[16])
 100 {
 101         /* Calculate the MD4 hash (NT compatible) of the password */
 102         memset(nt_p16, '\0', 16);
 103         E_md4hash(pwd, nt_p16);
 104
 105 #ifdef DEBUG_PASSWORD
 106         DEBUG(100,("nt_lm_owf_gen: pwd, nt#\n"));
 107         dump_data(120, pwd, strlen(pwd));
 108         dump_data(100, (char *)nt_p16, 16);
 109 #endif
 110
 111         E_deshash(pwd, (uchar *)p16);
 112
 113 #ifdef DEBUG_PASSWORD
 114         DEBUG(100,("nt_lm_owf_gen: pwd, lm#\n"));
 115         dump_data(120, pwd, strlen(pwd));
 116         dump_data(100, (char *)p16, 16);
 117 #endif
 118 }
 119
 120 /* Does both the NTLMv2 owfs of a user's password */
 121 BOOL ntv2_owf_gen(const uchar owf[16],
 122                   const char *user_in, const char *domain_in, uchar kr_buf[16])
 123 {
 124         smb_ucs2_t *user;
 125         smb_ucs2_t *domain;
 126
 127         size_t user_byte_len;
 128         size_t domain_byte_len;
 129
 130         HMACMD5Context ctx;
 131
 132         user_byte_len = push_ucs2_allocate(&user, user_in);
 133         if (user_byte_len == (size_t)-1) {
 134                 DEBUG(0, ("push_uss2_allocate() for user returned -1 (probably malloc() failure)\n"));
 135                 return False;
 136         }
 137
 138         domain_byte_len = push_ucs2_allocate(&domain, domain_in);
 139         if (domain_byte_len == (size_t)-1) {
 140                 DEBUG(0, ("push_uss2_allocate() for domain returned -1 (probably malloc() failure)\n"));
 141                 return False;
 142         }
 143
 144         strupper_w(user);
 145         strupper_w(domain);
 146
 147         SMB_ASSERT(user_byte_len >= 2);
 148         SMB_ASSERT(domain_byte_len >= 2);
 149
 150         /* We don't want null termination */
 151         user_byte_len = user_byte_len - 2;
 152         domain_byte_len = domain_byte_len - 2;
 153
 154         hmac_md5_init_limK_to_64(owf, 16, &ctx);
 155         hmac_md5_update((const unsigned char *)user, user_byte_len, &ctx);
 156         hmac_md5_update((const unsigned char *)domain, domain_byte_len, &ctx);
 157         hmac_md5_final(kr_buf, &ctx);
 158
 159 #ifdef DEBUG_PASSWORD
 160         DEBUG(100, ("ntv2_owf_gen: user, domain, owfkey, kr\n"));
 161         dump_data(100, (const char *)user, user_byte_len);
 162         dump_data(100, (const char *)domain, domain_byte_len);
 163         dump_data(100, owf, 16);
 164         dump_data(100, kr_buf, 16);
 165 #endif
 166
 167         SAFE_FREE(user);
 168         SAFE_FREE(domain);
 169         return True;
 170 }
 171
 172 /* Does the des encryption from the NT or LM MD4 hash. */
 173 void SMBOWFencrypt(const uchar passwd[16], const uchar *c8, uchar p24[24])
 174 {
 175         uchar p21[21];
 176
 177         ZERO_STRUCT(p21);
 178
 179         memcpy(p21, passwd, 16);
 180         E_P24(p21, c8, p24);
 181 }
 182
 183 /* Does the des encryption from the FIRST 8 BYTES of the NT or LM MD4 hash. */
 184 void NTLMSSPOWFencrypt(const uchar passwd[8], const uchar *ntlmchalresp, uchar p24[24])
 185 {
 186         uchar p21[21];
 187
 188         memset(p21,'\0',21);
 189         memcpy(p21, passwd, 8);
 190         memset(p21 + 8, 0xbd, 8);
 191
 192         E_P24(p21, ntlmchalresp, p24);
 193 #ifdef DEBUG_PASSWORD
 194         DEBUG(100,("NTLMSSPOWFencrypt: p21, c8, p24\n"));
 195         dump_data(100, (char *)p21, 21);
 196         dump_data(100, (const char *)ntlmchalresp, 8);
 197         dump_data(100, (char *)p24, 24);
 198 #endif
 199 }
 200
 201
 202 /* Does the NT MD4 hash then des encryption. */
 203
 204 void SMBNTencrypt(const char *passwd, uchar *c8, uchar *p24)
 205 {
 206         uchar p21[21];
 207
 208         memset(p21,'\0',21);
 209
 210         E_md4hash(passwd, p21);
 211         SMBOWFencrypt(p21, c8, p24);
 212
 213 #ifdef DEBUG_PASSWORD
 214         DEBUG(100,("SMBNTencrypt: nt#, challenge, response\n"));
 215         dump_data(100, (char *)p21, 16);
 216         dump_data(100, (char *)c8, 8);
 217         dump_data(100, (char *)p24, 24);
 218 #endif
 219 }
 220
 221 BOOL make_oem_passwd_hash(char data[516], const char *passwd, uchar old_pw_hash[16], BOOL unicode)
 222 {
 223         int new_pw_len = strlen(passwd) * (unicode ? 2 : 1);
 224
 225         if (new_pw_len > 512)
 226         {
 227                 DEBUG(0,("make_oem_passwd_hash: new password is too long.\n"));
 228                 return False;
 229         }
 230
 231         /*
 232          * Now setup the data area.
 233          * We need to generate a random fill
 234          * for this area to make it harder to
 235          * decrypt. JRA.
 236          */
 237         generate_random_buffer((unsigned char *)data, 516, False);
 238         push_string(NULL, &data[512 - new_pw_len], passwd, new_pw_len,
 239                     STR_NOALIGN | (unicode?STR_UNICODE:STR_ASCII));
 240         SIVAL(data, 512, new_pw_len);
 241
 242 #ifdef DEBUG_PASSWORD
 243         DEBUG(100,("make_oem_passwd_hash\n"));
 244         dump_data(100, data, 516);
 245 #endif
 246         SamOEMhash( (unsigned char *)data, (unsigned char *)old_pw_hash, 516);
 247
 248         return True;
 249 }
 250
 251 /* Does the md5 encryption from the NT hash for NTLMv2. */
 252 void SMBOWFencrypt_ntv2(const uchar kr[16],
 253                         const DATA_BLOB srv_chal,
 254                         const DATA_BLOB cli_chal,
 255                         uchar resp_buf[16])
 256 {
 257         HMACMD5Context ctx;
 258
 259         hmac_md5_init_limK_to_64(kr, 16, &ctx);
 260         hmac_md5_update(srv_chal.data, srv_chal.length, &ctx);
 261         hmac_md5_update(cli_chal.data, cli_chal.length, &ctx);
 262         hmac_md5_final(resp_buf, &ctx);
 263
 264 #ifdef DEBUG_PASSWORD
 265         DEBUG(100, ("SMBOWFencrypt_ntv2: srv_chal, cli_chal, resp_buf\n"));
 266         dump_data(100, srv_chal.data, srv_chal.length);
 267         dump_data(100, cli_chal.data, cli_chal.length);
 268         dump_data(100, resp_buf, 16);
 269 #endif
 270 }
 271
 272 void SMBsesskeygen_ntv2(const uchar kr[16],
 273                         const uchar * nt_resp, uint8 sess_key[16])
 274 {
 275         HMACMD5Context ctx;
 276
 277         hmac_md5_init_limK_to_64(kr, 16, &ctx);
 278         hmac_md5_update(nt_resp, 16, &ctx);
 279         hmac_md5_final((unsigned char *)sess_key, &ctx);
 280
 281 #ifdef DEBUG_PASSWORD
 282         DEBUG(100, ("SMBsesskeygen_ntv2:\n"));
 283         dump_data(100, sess_key, 16);
 284 #endif
 285 }
 286
 287 void SMBsesskeygen_ntv1(const uchar kr[16],
 288                         const uchar * nt_resp, uint8 sess_key[16])
 289 {
 290         mdfour((unsigned char *)sess_key, kr, 16);
 291
 292 #ifdef DEBUG_PASSWORD
 293         DEBUG(100, ("SMBsesskeygen_ntv1:\n"));
 294         dump_data(100, sess_key, 16);
 295 #endif
 296 }
 297
 298 DATA_BLOB NTLMv2_generate_response(uchar ntlm_v2_hash[16],
 299                                    DATA_BLOB server_chal, size_t client_chal_length)
 300 {
 301         uchar ntlmv2_response[16];
 302         DATA_BLOB ntlmv2_client_data;
 303         DATA_BLOB final_response;
 304
 305         /* NTLMv2 */
 306
 307         /* We also get to specify some random data */
 308         ntlmv2_client_data = data_blob(NULL, client_chal_length);
 309         generate_random_buffer(ntlmv2_client_data.data, ntlmv2_client_data.length, False);
 310
 311         /* Given that data, and the challenge from the server, generate a response */
 312         SMBOWFencrypt_ntv2(ntlm_v2_hash, server_chal, ntlmv2_client_data, ntlmv2_response);
 313
 314         /* put it into nt_response, for the code below to put into the packet */
 315         final_response = data_blob(NULL, ntlmv2_client_data.length + sizeof(ntlmv2_response));
 316         memcpy(final_response.data, ntlmv2_response, sizeof(ntlmv2_response));
 317         /* after the first 16 bytes is the random data we generated above, so the server can verify us with it */
 318         memcpy(final_response.data + sizeof(ntlmv2_response), ntlmv2_client_data.data, ntlmv2_client_data.length);
 319         data_blob_free(&ntlmv2_client_data);
 320
 321         return final_response;
 322 }
 323
 324 BOOL SMBNTLMv2encrypt(const char *user, const char *domain, const char *password,
 325                       const DATA_BLOB server_chal,
 326                       DATA_BLOB *lm_response, DATA_BLOB *nt_response,
 327                       DATA_BLOB *session_key)
 328 {
 329         uchar nt_hash[16];
 330         uchar ntlm_v2_hash[16];
 331         E_md4hash(password, nt_hash);
 332
 333         /* We don't use the NT# directly.  Instead we use it mashed up with
 334            the username and domain.
 335            This prevents username swapping during the auth exchange
 336         */
 337         if (!ntv2_owf_gen(nt_hash, user, domain, ntlm_v2_hash)) {
 338                 return False;
 339         }
 340
 341         *nt_response = NTLMv2_generate_response(ntlm_v2_hash, server_chal, 64 /* pick a number, > 8 */);
 342
 343         /* LMv2 */
 344
 345         *lm_response = NTLMv2_generate_response(ntlm_v2_hash, server_chal, 8);
 346
 347         *session_key = data_blob(NULL, 16);
 348
 349         /* The NTLMv2 calculations also provide a session key, for signing etc later */
 350         /* use only the first 16 bytes of nt_response for session key */
 351         SMBsesskeygen_ntv2(ntlm_v2_hash, nt_response->data, session_key->data);
 352
 353         return True;
 354 }
 355
 356 /***********************************************************
 357  encode a password buffer.  The caller gets to figure out
 358  what to put in it.
 359 ************************************************************/
 360 BOOL encode_pw_buffer(char buffer[516], char *new_pw, int new_pw_length)
 361 {
 362         generate_random_buffer((unsigned char *)buffer, 516, True);
 363
 364         memcpy(&buffer[512 - new_pw_length], new_pw, new_pw_length);
 365
 366         /*
 367          * The length of the new password is in the last 4 bytes of
 368          * the data buffer.
 369          */
 370         SIVAL(buffer, 512, new_pw_length);
 371
 372         return True;
 373 }
 374
 375 /***********************************************************
 376  decode a password buffer
 377  *new_pw_len is the length in bytes of the possibly mulitbyte
 378  returned password including termination.
 379 ************************************************************/
 380 BOOL decode_pw_buffer(char in_buffer[516], char *new_pwrd,
 381                       int new_pwrd_size, uint32 *new_pw_len)
 382 {
 383         int byte_len=0;
 384
 385         /*
 386           Warning !!! : This function is called from some rpc call.
 387           The password IN the buffer is a UNICODE string.
 388           The password IN new_pwrd is an ASCII string
 389           If you reuse that code somewhere else check first.
 390         */
 391
 392         /* The length of the new password is in the last 4 bytes of the data buffer. */
 393
 394         byte_len = IVAL(in_buffer, 512);
 395
 396 #ifdef DEBUG_PASSWORD
 397         dump_data(100, in_buffer, 516);
 398 #endif
 399
 400         /* Password cannot be longer than 128 characters */
 401         if ( (byte_len < 0) || (byte_len > new_pwrd_size - 1)) {
 402                 DEBUG(0, ("decode_pw_buffer: incorrect password length (%d).\n", byte_len));
 403                 DEBUG(0, ("decode_pw_buffer: check that 'encrypt passwords = yes'\n"));
 404                 return False;
 405         }
 406
 407         /* decode into the return buffer.  Buffer must be a pstring */
 408         *new_pw_len = pull_string(NULL, new_pwrd, &in_buffer[512 - byte_len], new_pwrd_size, byte_len, STR_UNICODE);
 409
 410 #ifdef DEBUG_PASSWORD
 411         DEBUG(100,("decode_pw_buffer: new_pwrd: "));
 412         dump_data(100, (char *)new_pwrd, *new_pw_len);
 413         DEBUG(100,("multibyte len:%d\n", *new_pw_len));
 414         DEBUG(100,("original char len:%d\n", byte_len/2));
 415 #endif
 416
 417         return True;
 418 }
 419
 420 /***********************************************************
 421  SMB signing - setup the MAC key.
 422 ************************************************************/
 423
 424 void cli_calculate_mac_key(struct cli_state *cli, const uchar user_session_key[16], const DATA_BLOB response)
 425 {
 426
 427         memcpy(&cli->sign_info.mac_key[0], user_session_key, 16);
 428         memcpy(&cli->sign_info.mac_key[16],response.data, MIN(response.length, 40 - 16));
 429         cli->sign_info.mac_key_len = MIN(response.length + 16, 40);
 430         cli->sign_info.use_smb_signing = True;
 431
 432         /* These calls are INCONPATIBLE with SMB signing */
 433         cli->readbraw_supported = False;
 434         cli->writebraw_supported = False;
 435
 436         /* Reset the sequence number in case we had a previous (aborted) attempt */
 437         cli->sign_info.send_seq_num = 2;
 438 }
 439
 440 /***********************************************************
 441  SMB signing - calculate a MAC to send.
 442 ************************************************************/
 443
 444 void cli_caclulate_sign_mac(struct cli_state *cli)
 445 {
 446         unsigned char calc_md5_mac[16];
 447         struct MD5Context md5_ctx;
 448
 449         if (cli->sign_info.temp_smb_signing) {
 450                 memcpy(&cli->outbuf[smb_ss_field], "SignRequest", 8);
 451                 cli->sign_info.temp_smb_signing = False;
 452                 return;
 453         }
 454
 455         if (!cli->sign_info.use_smb_signing) {
 456                 return;
 457         }
 458
 459         /*
 460          * Firstly put the sequence number into the first 4 bytes.
 461          * and zero out the next 4 bytes.
 462          */
 463         SIVAL(cli->outbuf, smb_ss_field, cli->sign_info.send_seq_num);
 464         SIVAL(cli->outbuf, smb_ss_field + 4, 0);
 465
 466         /* Calculate the 16 byte MAC and place first 8 bytes into the field. */
 467         MD5Init(&md5_ctx);
 468         MD5Update(&md5_ctx, cli->sign_info.mac_key, cli->sign_info.mac_key_len);
 469         MD5Update(&md5_ctx, cli->outbuf + 4, smb_len(cli->outbuf));
 470         MD5Final(calc_md5_mac, &md5_ctx);
 471
 472         memcpy(&cli->outbuf[smb_ss_field], calc_md5_mac, 8);
 473
 474 /*      cli->outbuf[smb_ss_field+2]=0;
 475         Uncomment this to test if the remote server actually verifies signitures...*/
 476         cli->sign_info.send_seq_num++;
 477         cli->sign_info.reply_seq_num = cli->sign_info.send_seq_num;
 478         cli->sign_info.send_seq_num++;
 479 }
 480
 481 /***********************************************************
 482  SMB signing - check a MAC sent by server.
 483 ************************************************************/
 484
 485 BOOL cli_check_sign_mac(struct cli_state *cli)
 486 {
 487         unsigned char calc_md5_mac[16];
 488         unsigned char server_sent_mac[8];
 489         struct MD5Context md5_ctx;
 490
 491         if (cli->sign_info.temp_smb_signing) {
 492                 return True;
 493         }
 494
 495         if (!cli->sign_info.use_smb_signing) {
 496                 return True;
 497         }
 498
 499         /*
 500          * Firstly put the sequence number into the first 4 bytes.
 501          * and zero out the next 4 bytes.
 502          */
 503
 504         memcpy(server_sent_mac, &cli->inbuf[smb_ss_field], sizeof(server_sent_mac));
 505
 506         SIVAL(cli->inbuf, smb_ss_field, cli->sign_info.reply_seq_num);
 507         SIVAL(cli->inbuf, smb_ss_field + 4, 0);
 508
 509         /* Calculate the 16 byte MAC and place first 8 bytes into the field. */
 510         MD5Init(&md5_ctx);
 511         MD5Update(&md5_ctx, cli->sign_info.mac_key, cli->sign_info.mac_key_len);
 512         MD5Update(&md5_ctx, cli->inbuf + 4, smb_len(cli->inbuf));
 513         MD5Final(calc_md5_mac, &md5_ctx);
 514
 515         return (memcmp(server_sent_mac, calc_md5_mac, 8) == 0);
 516 }