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
  80         /* Password must be converted to DOS charset - null terminated, uppercase. */
  81         push_ascii(dospwd, passwd, sizeof(dospwd), STR_UPPER|STR_TERMINATE);
  82
  83         /* Only the fisrt 14 chars are considered, password need not be null terminated. */
  84         E_P16(dospwd, p16);
  85
  86         ZERO_STRUCT(dospwd);
  87 }
  88
  89 /**
  90  * Creates the MD4 and DES (LM) Hash of the users password.
  91  * MD4 is of the NT Unicode, DES is of the DOS UPPERCASE password.
  92  * @param passwd password in 'unix' charset.
  93  * @param nt_p16 return password hashed with md4, caller allocated 16 byte buffer
  94  * @param p16 return password hashed with des, caller allocated 16 byte buffer
  95  */
  96
  97 /* Does both the NT and LM owfs of a user's password */
  98 void nt_lm_owf_gen(const char *pwd, uchar nt_p16[16], uchar p16[16])
  99 {
 100         /* Calculate the MD4 hash (NT compatible) of the password */
 101         memset(nt_p16, '\0', 16);
 102         E_md4hash(pwd, nt_p16);
 103
 104 #ifdef DEBUG_PASSWORD
 105         DEBUG(100,("nt_lm_owf_gen: pwd, nt#\n"));
 106         dump_data(120, pwd, strlen(pwd));
 107         dump_data(100, (char *)nt_p16, 16);
 108 #endif
 109
 110         E_deshash(pwd, (uchar *)p16);
 111
 112 #ifdef DEBUG_PASSWORD
 113         DEBUG(100,("nt_lm_owf_gen: pwd, lm#\n"));
 114         dump_data(120, pwd, strlen(pwd));
 115         dump_data(100, (char *)p16, 16);
 116 #endif
 117 }
 118
 119 /* Does both the NTLMv2 owfs of a user's password */
 120 BOOL ntv2_owf_gen(const uchar owf[16],
 121                   const char *user_in, const char *domain_in, uchar kr_buf[16])
 122 {
 123         smb_ucs2_t *user;
 124         smb_ucs2_t *domain;
 125
 126         size_t user_byte_len;
 127         size_t domain_byte_len;
 128
 129         HMACMD5Context ctx;
 130
 131         user_byte_len = push_ucs2_allocate(&user, user_in);
 132         if (user_byte_len == (size_t)-1) {
 133                 DEBUG(0, ("push_uss2_allocate() for user returned -1 (probably malloc() failure)\n"));
 134                 return False;
 135         }
 136
 137         domain_byte_len = push_ucs2_allocate(&domain, domain_in);
 138         if (domain_byte_len == (size_t)-1) {
 139                 DEBUG(0, ("push_uss2_allocate() for domain returned -1 (probably malloc() failure)\n"));
 140                 return False;
 141         }
 142
 143         strupper_w(user);
 144         strupper_w(domain);
 145
 146         SMB_ASSERT(user_byte_len >= 2);
 147         SMB_ASSERT(domain_byte_len >= 2);
 148
 149         /* We don't want null termination */
 150         user_byte_len = user_byte_len - 2;
 151         domain_byte_len = domain_byte_len - 2;
 152
 153         hmac_md5_init_limK_to_64(owf, 16, &ctx);
 154         hmac_md5_update((const unsigned char *)user, user_byte_len, &ctx);
 155         hmac_md5_update((const unsigned char *)domain, domain_byte_len, &ctx);
 156         hmac_md5_final(kr_buf, &ctx);
 157
 158 #ifdef DEBUG_PASSWORD
 159         DEBUG(100, ("ntv2_owf_gen: user, domain, owfkey, kr\n"));
 160         dump_data(100, (const char *)user, user_byte_len);
 161         dump_data(100, (const char *)domain, domain_byte_len);
 162         dump_data(100, owf, 16);
 163         dump_data(100, kr_buf, 16);
 164 #endif
 165
 166         SAFE_FREE(user);
 167         SAFE_FREE(domain);
 168         return True;
 169 }
 170
 171 /* Does the des encryption from the NT or LM MD4 hash. */
 172 void SMBOWFencrypt(const uchar passwd[16], const uchar *c8, uchar p24[24])
 173 {
 174         uchar p21[21];
 175
 176         ZERO_STRUCT(p21);
 177
 178         memcpy(p21, passwd, 16);
 179         E_P24(p21, c8, p24);
 180 }
 181
 182 /* Does the des encryption from the FIRST 8 BYTES of the NT or LM MD4 hash. */
 183 void NTLMSSPOWFencrypt(const uchar passwd[8], const uchar *ntlmchalresp, uchar p24[24])
 184 {
 185         uchar p21[21];
 186
 187         memset(p21,'\0',21);
 188         memcpy(p21, passwd, 8);
 189         memset(p21 + 8, 0xbd, 8);
 190
 191         E_P24(p21, ntlmchalresp, p24);
 192 #ifdef DEBUG_PASSWORD
 193         DEBUG(100,("NTLMSSPOWFencrypt: p21, c8, p24\n"));
 194         dump_data(100, (char *)p21, 21);
 195         dump_data(100, (const char *)ntlmchalresp, 8);
 196         dump_data(100, (char *)p24, 24);
 197 #endif
 198 }
 199
 200
 201 /* Does the NT MD4 hash then des encryption. */
 202
 203 void SMBNTencrypt(const char *passwd, uchar *c8, uchar *p24)
 204 {
 205         uchar p21[21];
 206
 207         memset(p21,'\0',21);
 208
 209         E_md4hash(passwd, p21);
 210         SMBOWFencrypt(p21, c8, p24);
 211
 212 #ifdef DEBUG_PASSWORD
 213         DEBUG(100,("SMBNTencrypt: nt#, challenge, response\n"));
 214         dump_data(100, (char *)p21, 16);
 215         dump_data(100, (char *)c8, 8);
 216         dump_data(100, (char *)p24, 24);
 217 #endif
 218 }
 219
 220 BOOL make_oem_passwd_hash(char data[516], const char *passwd, uchar old_pw_hash[16], BOOL unicode)
 221 {
 222         int new_pw_len = strlen(passwd) * (unicode ? 2 : 1);
 223
 224         if (new_pw_len > 512)
 225         {
 226                 DEBUG(0,("make_oem_passwd_hash: new password is too long.\n"));
 227                 return False;
 228         }
 229
 230         /*
 231          * Now setup the data area.
 232          * We need to generate a random fill
 233          * for this area to make it harder to
 234          * decrypt. JRA.
 235          */
 236         generate_random_buffer((unsigned char *)data, 516, False);
 237         push_string(NULL, &data[512 - new_pw_len], passwd, new_pw_len,
 238                     STR_NOALIGN | (unicode?STR_UNICODE:STR_ASCII));
 239         SIVAL(data, 512, new_pw_len);
 240
 241 #ifdef DEBUG_PASSWORD
 242         DEBUG(100,("make_oem_passwd_hash\n"));
 243         dump_data(100, data, 516);
 244 #endif
 245         SamOEMhash( (unsigned char *)data, (unsigned char *)old_pw_hash, 516);
 246
 247         return True;
 248 }
 249
 250 /* Does the md5 encryption from the NT hash for NTLMv2. */
 251 void SMBOWFencrypt_ntv2(const uchar kr[16],
 252                         const DATA_BLOB *srv_chal,
 253                         const DATA_BLOB *cli_chal,
 254                         uchar resp_buf[16])
 255 {
 256         HMACMD5Context ctx;
 257
 258         hmac_md5_init_limK_to_64(kr, 16, &ctx);
 259         hmac_md5_update(srv_chal->data, srv_chal->length, &ctx);
 260         hmac_md5_update(cli_chal->data, cli_chal->length, &ctx);
 261         hmac_md5_final(resp_buf, &ctx);
 262
 263 #ifdef DEBUG_PASSWORD
 264         DEBUG(100, ("SMBOWFencrypt_ntv2: srv_chal, cli_chal, resp_buf\n"));
 265         dump_data(100, srv_chal->data, srv_chal->length);
 266         dump_data(100, cli_chal->data, cli_chal->length);
 267         dump_data(100, resp_buf, 16);
 268 #endif
 269 }
 270
 271 void SMBsesskeygen_ntv2(const uchar kr[16],
 272                         const uchar * nt_resp, uint8 sess_key[16])
 273 {
 274         /* a very nice, 128 bit, variable session key */
 275
 276         HMACMD5Context ctx;
 277
 278         hmac_md5_init_limK_to_64(kr, 16, &ctx);
 279         hmac_md5_update(nt_resp, 16, &ctx);
 280         hmac_md5_final((unsigned char *)sess_key, &ctx);
 281
 282 #ifdef DEBUG_PASSWORD
 283         DEBUG(100, ("SMBsesskeygen_ntv2:\n"));
 284         dump_data(100, sess_key, 16);
 285 #endif
 286 }
 287
 288 void SMBsesskeygen_ntv1(const uchar kr[16],
 289                         const uchar * nt_resp, uint8 sess_key[16])
 290 {
 291         /* yes, this session key does not change - yes, this
 292            is a problem - but it is 128 bits */
 293
 294         mdfour((unsigned char *)sess_key, kr, 16);
 295
 296 #ifdef DEBUG_PASSWORD
 297         DEBUG(100, ("SMBsesskeygen_ntv1:\n"));
 298         dump_data(100, sess_key, 16);
 299 #endif
 300 }
 301
 302 void SMBsesskeygen_lmv1(const uchar lm_hash[16],
 303                         const uchar lm_resp[24], /* only uses 8 */
 304                         uint8 sess_key[16])
 305 {
 306         /* Calculate the LM session key (effective length 40 bits,
 307            but changes with each session) */
 308
 309         uchar p24[24];
 310         uchar partial_lm_hash[16];
 311
 312         memcpy(partial_lm_hash, lm_hash, 8);
 313         memset(partial_lm_hash + 8, 0xbd, 8);
 314
 315         SMBOWFencrypt(lm_hash, lm_resp, p24);
 316
 317         memcpy(sess_key, p24, 16);
 318         sess_key[5] = 0xe5;
 319         sess_key[6] = 0x38;
 320         sess_key[7] = 0xb0;
 321
 322 #ifdef DEBUG_PASSWORD
 323         DEBUG(100, ("SMBsesskeygen_lmv1:\n"));
 324         dump_data(100, sess_key, 16);
 325 #endif
 326 }
 327
 328 DATA_BLOB NTLMv2_generate_names_blob(const char *hostname,
 329                                      const char *domain)
 330 {
 331         DATA_BLOB names_blob = data_blob(NULL, 0);
 332
 333         msrpc_gen(&names_blob, "aaa",
 334                   True, NTLMSSP_NAME_TYPE_DOMAIN, domain,
 335                   True, NTLMSSP_NAME_TYPE_SERVER, hostname,
 336                   True, 0, "");
 337         return names_blob;
 338 }
 339
 340 static DATA_BLOB NTLMv2_generate_client_data(const DATA_BLOB *names_blob)
 341 {
 342         uchar client_chal[8];
 343         DATA_BLOB response = data_blob(NULL, 0);
 344         char long_date[8];
 345
 346         generate_random_buffer(client_chal, sizeof(client_chal), False);
 347
 348         put_long_date(long_date, time(NULL));
 349
 350         /* See http://www.ubiqx.org/cifs/SMB.html#SMB.8.5 */
 351
 352         msrpc_gen(&response, "ddbbdb",
 353                   0x00000101,     /* Header  */
 354                   0,              /* 'Reserved'  */
 355                   long_date, 8,   /* Timestamp */
 356                   client_chal, 8, /* client challenge */
 357                   0,              /* Unknown */
 358                   names_blob->data, names_blob->length);        /* End of name list */
 359
 360         return response;
 361 }
 362
 363 static DATA_BLOB NTLMv2_generate_response(const uchar ntlm_v2_hash[16],
 364                                           const DATA_BLOB *server_chal,
 365                                           const DATA_BLOB *names_blob)
 366 {
 367         uchar ntlmv2_response[16];
 368         DATA_BLOB ntlmv2_client_data;
 369         DATA_BLOB final_response;
 370
 371         /* NTLMv2 */
 372         /* generate some data to pass into the response function - including
 373            the hostname and domain name of the server */
 374         ntlmv2_client_data = NTLMv2_generate_client_data(names_blob);
 375
 376         /* Given that data, and the challenge from the server, generate a response */
 377         SMBOWFencrypt_ntv2(ntlm_v2_hash, server_chal, &ntlmv2_client_data, ntlmv2_response);
 378
 379         final_response = data_blob(NULL, sizeof(ntlmv2_response) + ntlmv2_client_data.length);
 380
 381         memcpy(final_response.data, ntlmv2_response, sizeof(ntlmv2_response));
 382
 383         memcpy(final_response.data+sizeof(ntlmv2_response),
 384                ntlmv2_client_data.data, ntlmv2_client_data.length);
 385
 386         data_blob_free(&ntlmv2_client_data);
 387
 388         return final_response;
 389 }
 390
 391 static DATA_BLOB LMv2_generate_response(const uchar ntlm_v2_hash[16],
 392                                         const DATA_BLOB *server_chal)
 393 {
 394         uchar lmv2_response[16];
 395         DATA_BLOB lmv2_client_data = data_blob(NULL, 8);
 396         DATA_BLOB final_response = data_blob(NULL, 24);
 397
 398         /* LMv2 */
 399         /* client-supplied random data */
 400         generate_random_buffer(lmv2_client_data.data, lmv2_client_data.length, False);
 401
 402         /* Given that data, and the challenge from the server, generate a response */
 403         SMBOWFencrypt_ntv2(ntlm_v2_hash, server_chal, &lmv2_client_data, lmv2_response);
 404         memcpy(final_response.data, lmv2_response, sizeof(lmv2_response));
 405
 406         /* after the first 16 bytes is the random data we generated above,
 407            so the server can verify us with it */
 408         memcpy(final_response.data+sizeof(lmv2_response),
 409                lmv2_client_data.data, lmv2_client_data.length);
 410
 411         data_blob_free(&lmv2_client_data);
 412
 413         return final_response;
 414 }
 415
 416 BOOL SMBNTLMv2encrypt(const char *user, const char *domain, const char *password,
 417                       const DATA_BLOB *server_chal,
 418                       const DATA_BLOB *names_blob,
 419                       DATA_BLOB *lm_response, DATA_BLOB *nt_response,
 420                       DATA_BLOB *nt_session_key)
 421 {
 422         uchar nt_hash[16];
 423         uchar ntlm_v2_hash[16];
 424         E_md4hash(password, nt_hash);
 425
 426         /* We don't use the NT# directly.  Instead we use it mashed up with
 427            the username and domain.
 428            This prevents username swapping during the auth exchange
 429         */
 430         if (!ntv2_owf_gen(nt_hash, user, domain, ntlm_v2_hash)) {
 431                 return False;
 432         }
 433
 434         if (nt_response) {
 435                 *nt_response = NTLMv2_generate_response(ntlm_v2_hash, server_chal,
 436                                                         names_blob);
 437                 if (nt_session_key) {
 438                         *nt_session_key = data_blob(NULL, 16);
 439
 440                         /* The NTLMv2 calculations also provide a session key, for signing etc later */
 441                         /* use only the first 16 bytes of nt_response for session key */
 442                         SMBsesskeygen_ntv2(ntlm_v2_hash, nt_response->data, nt_session_key->data);
 443                 }
 444         }
 445
 446         /* LMv2 */
 447
 448         if (lm_response) {
 449                 *lm_response = LMv2_generate_response(ntlm_v2_hash, server_chal);
 450         }
 451
 452         return True;
 453 }
 454
 455 /***********************************************************
 456  encode a password buffer.  The caller gets to figure out
 457  what to put in it.
 458 ************************************************************/
 459 BOOL encode_pw_buffer(char buffer[516], char *new_pw, int new_pw_length)
 460 {
 461         generate_random_buffer((unsigned char *)buffer, 516, True);
 462
 463         memcpy(&buffer[512 - new_pw_length], new_pw, new_pw_length);
 464
 465         /*
 466          * The length of the new password is in the last 4 bytes of
 467          * the data buffer.
 468          */
 469         SIVAL(buffer, 512, new_pw_length);
 470
 471         return True;
 472 }
 473
 474 /***********************************************************
 475  decode a password buffer
 476  *new_pw_len is the length in bytes of the possibly mulitbyte
 477  returned password including termination.
 478 ************************************************************/
 479 BOOL decode_pw_buffer(char in_buffer[516], char *new_pwrd,
 480                       int new_pwrd_size, uint32 *new_pw_len)
 481 {
 482         int byte_len=0;
 483
 484         /*
 485           Warning !!! : This function is called from some rpc call.
 486           The password IN the buffer is a UNICODE string.
 487           The password IN new_pwrd is an ASCII string
 488           If you reuse that code somewhere else check first.
 489         */
 490
 491         /* The length of the new password is in the last 4 bytes of the data buffer. */
 492
 493         byte_len = IVAL(in_buffer, 512);
 494
 495 #ifdef DEBUG_PASSWORD
 496         dump_data(100, in_buffer, 516);
 497 #endif
 498
 499         /* Password cannot be longer than 128 characters */
 500         if ( (byte_len < 0) || (byte_len > new_pwrd_size - 1)) {
 501                 DEBUG(0, ("decode_pw_buffer: incorrect password length (%d).\n", byte_len));
 502                 DEBUG(0, ("decode_pw_buffer: check that 'encrypt passwords = yes'\n"));
 503                 return False;
 504         }
 505
 506         /* decode into the return buffer.  Buffer must be a pstring */
 507         *new_pw_len = pull_string(NULL, new_pwrd, &in_buffer[512 - byte_len], new_pwrd_size, byte_len, STR_UNICODE);
 508
 509 #ifdef DEBUG_PASSWORD
 510         DEBUG(100,("decode_pw_buffer: new_pwrd: "));
 511         dump_data(100, (char *)new_pwrd, *new_pw_len);
 512         DEBUG(100,("multibyte len:%d\n", *new_pw_len));
 513         DEBUG(100,("original char len:%d\n", byte_len/2));
 514 #endif
 515
 516         return True;
 517 }