source3/rpc_parse/parse_prs.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Samba memory buffer functions
   4    Copyright (C) Andrew Tridgell              1992-1997
   5    Copyright (C) Luke Kenneth Casson Leighton 1996-1997
   6    Copyright (C) Jeremy Allison               1999
   7    Copyright (C) Andrew Bartlett              2003.
   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
  25 #undef DBGC_CLASS
  26 #define DBGC_CLASS DBGC_RPC_PARSE
  27
  28 /**
  29  * Dump a prs to a file: from the current location through to the end.
  30  **/
  31 void prs_dump(const char *name, int v, prs_struct *ps)
  32 {
  33         prs_dump_region(name, v, ps, ps->data_offset, ps->buffer_size);
  34 }
  35
  36 /**
  37  * Dump from the start of the prs to the current location.
  38  **/
  39 void prs_dump_before(const char *name, int v, prs_struct *ps)
  40 {
  41         prs_dump_region(name, v, ps, 0, ps->data_offset);
  42 }
  43
  44 /**
  45  * Dump everything from the start of the prs up to the current location.
  46  **/
  47 void prs_dump_region(const char *name, int v, prs_struct *ps,
  48                      int from_off, int to_off)
  49 {
  50         int fd, i;
  51         char *fname = NULL;
  52         ssize_t sz;
  53         if (DEBUGLEVEL < 50) return;
  54         for (i=1;i<100;i++) {
  55                 if (v != -1) {
  56                         if (asprintf(&fname,"/tmp/%s_%d.%d.prs", name, v, i) < 0) {
  57                                 return;
  58                         }
  59                 } else {
  60                         if (asprintf(&fname,"/tmp/%s.%d.prs", name, i) < 0) {
  61                                 return;
  62                         }
  63                 }
  64                 fd = open(fname, O_WRONLY|O_CREAT|O_EXCL, 0644);
  65                 if (fd != -1 || errno != EEXIST) break;
  66         }
  67         if (fd != -1) {
  68                 sz = write(fd, ps->data_p + from_off, to_off - from_off);
  69                 i = close(fd);
  70                 if ( (sz != to_off-from_off) || (i != 0) ) {
  71                         DEBUG(0,("Error writing/closing %s: %ld!=%ld %d\n", fname, (unsigned long)sz, (unsigned long)to_off-from_off, i ));
  72                 } else {
  73                         DEBUG(0,("created %s\n", fname));
  74                 }
  75         }
  76         SAFE_FREE(fname);
  77 }
  78
  79 /*******************************************************************
  80  Debug output for parsing info
  81
  82  XXXX side-effect of this function is to increase the debug depth XXXX.
  83
  84 ********************************************************************/
  85
  86 void prs_debug(prs_struct *ps, int depth, const char *desc, const char *fn_name)
  87 {
  88         DEBUG(5+depth, ("%s%06x %s %s\n", tab_depth(5+depth,depth), ps->data_offset, fn_name, desc));
  89 }
  90
  91 /**
  92  * Initialise an expandable parse structure.
  93  *
  94  * @param size Initial buffer size.  If >0, a new buffer will be
  95  * created with malloc().
  96  *
  97  * @return False if allocation fails, otherwise True.
  98  **/
  99
 100 bool prs_init(prs_struct *ps, uint32 size, TALLOC_CTX *ctx, bool io)
 101 {
 102         ZERO_STRUCTP(ps);
 103         ps->io = io;
 104         ps->bigendian_data = RPC_LITTLE_ENDIAN;
 105         ps->align = RPC_PARSE_ALIGN;
 106         ps->is_dynamic = False;
 107         ps->data_offset = 0;
 108         ps->buffer_size = 0;
 109         ps->data_p = NULL;
 110         ps->mem_ctx = ctx;
 111
 112         if (size != 0) {
 113                 ps->buffer_size = size;
 114                 if((ps->data_p = (char *)SMB_MALLOC((size_t)size)) == NULL) {
 115                         DEBUG(0,("prs_init: malloc fail for %u bytes.\n", (unsigned int)size));
 116                         return False;
 117                 }
 118                 memset(ps->data_p, '\0', (size_t)size);
 119                 ps->is_dynamic = True; /* We own this memory. */
 120         } else if (MARSHALLING(ps)) {
 121                 /* If size is zero and we're marshalling we should allocate memory on demand. */
 122                 ps->is_dynamic = True;
 123         }
 124
 125         return True;
 126 }
 127
 128 /*******************************************************************
 129  Delete the memory in a parse structure - if we own it.
 130
 131  NOTE: Contrary to the somewhat confusing naming, this function is not
 132        intended for freeing memory allocated by prs_alloc_mem().  That memory
 133        is attached to the talloc context given by ps->mem_ctx.
 134  ********************************************************************/
 135
 136 void prs_mem_free(prs_struct *ps)
 137 {
 138         if(ps->is_dynamic)
 139                 SAFE_FREE(ps->data_p);
 140         ps->is_dynamic = False;
 141         ps->buffer_size = 0;
 142         ps->data_offset = 0;
 143 }
 144
 145 /*******************************************************************
 146  Clear the memory in a parse structure.
 147  ********************************************************************/
 148
 149 void prs_mem_clear(prs_struct *ps)
 150 {
 151         if (ps->buffer_size)
 152                 memset(ps->data_p, '\0', (size_t)ps->buffer_size);
 153 }
 154
 155 /*******************************************************************
 156  Allocate memory when unmarshalling... Always zero clears.
 157  ********************************************************************/
 158
 159 #if defined(PARANOID_MALLOC_CHECKER)
 160 char *prs_alloc_mem_(prs_struct *ps, size_t size, unsigned int count)
 161 #else
 162 char *prs_alloc_mem(prs_struct *ps, size_t size, unsigned int count)
 163 #endif
 164 {
 165         char *ret = NULL;
 166
 167         if (size && count) {
 168                 /* We can't call the type-safe version here. */
 169                 ret = (char *)_talloc_zero_array(ps->mem_ctx, size, count,
 170                                                  "parse_prs");
 171         }
 172         return ret;
 173 }
 174
 175 /*******************************************************************
 176  Return the current talloc context we're using.
 177  ********************************************************************/
 178
 179 TALLOC_CTX *prs_get_mem_context(prs_struct *ps)
 180 {
 181         return ps->mem_ctx;
 182 }
 183
 184 /*******************************************************************
 185  Hand some already allocated memory to a prs_struct.
 186  ********************************************************************/
 187
 188 void prs_give_memory(prs_struct *ps, char *buf, uint32 size, bool is_dynamic)
 189 {
 190         ps->is_dynamic = is_dynamic;
 191         ps->data_p = buf;
 192         ps->buffer_size = size;
 193 }
 194
 195 /*******************************************************************
 196  Take some memory back from a prs_struct.
 197  ********************************************************************/
 198
 199 char *prs_take_memory(prs_struct *ps, uint32 *psize)
 200 {
 201         char *ret = ps->data_p;
 202         if(psize)
 203                 *psize = ps->buffer_size;
 204         ps->is_dynamic = False;
 205         prs_mem_free(ps);
 206         return ret;
 207 }
 208
 209 /*******************************************************************
 210  Set a prs_struct to exactly a given size. Will grow or tuncate if neccessary.
 211  ********************************************************************/
 212
 213 bool prs_set_buffer_size(prs_struct *ps, uint32 newsize)
 214 {
 215         if (newsize > ps->buffer_size)
 216                 return prs_force_grow(ps, newsize - ps->buffer_size);
 217
 218         if (newsize < ps->buffer_size) {
 219                 ps->buffer_size = newsize;
 220
 221                 /* newsize == 0 acts as a free and set pointer to NULL */
 222                 if (newsize == 0) {
 223                         SAFE_FREE(ps->data_p);
 224                 } else {
 225                         ps->data_p = (char *)SMB_REALLOC(ps->data_p, newsize);
 226
 227                         if (ps->data_p == NULL) {
 228                                 DEBUG(0,("prs_set_buffer_size: Realloc failure for size %u.\n",
 229                                         (unsigned int)newsize));
 230                                 DEBUG(0,("prs_set_buffer_size: Reason %s\n",strerror(errno)));
 231                                 return False;
 232                         }
 233                 }
 234         }
 235
 236         return True;
 237 }
 238
 239 /*******************************************************************
 240  Attempt, if needed, to grow a data buffer.
 241  Also depends on the data stream mode (io).
 242  ********************************************************************/
 243
 244 bool prs_grow(prs_struct *ps, uint32 extra_space)
 245 {
 246         uint32 new_size;
 247
 248         ps->grow_size = MAX(ps->grow_size, ps->data_offset + extra_space);
 249
 250         if(ps->data_offset + extra_space <= ps->buffer_size)
 251                 return True;
 252
 253         /*
 254          * We cannot grow the buffer if we're not reading
 255          * into the prs_struct, or if we don't own the memory.
 256          */
 257
 258         if(UNMARSHALLING(ps) || !ps->is_dynamic) {
 259                 DEBUG(0,("prs_grow: Buffer overflow - unable to expand buffer by %u bytes.\n",
 260                                 (unsigned int)extra_space));
 261                 return False;
 262         }
 263
 264         /*
 265          * Decide how much extra space we really need.
 266          */
 267
 268         extra_space -= (ps->buffer_size - ps->data_offset);
 269         if(ps->buffer_size == 0) {
 270
 271                 /*
 272                  * Start with 128 bytes (arbitrary value), enough for small rpc
 273                  * requests
 274                  */
 275                 new_size = MAX(128, extra_space);
 276
 277                 if((ps->data_p = (char *)SMB_MALLOC(new_size)) == NULL) {
 278                         DEBUG(0,("prs_grow: Malloc failure for size %u.\n", (unsigned int)new_size));
 279                         return False;
 280                 }
 281                 memset(ps->data_p, '\0', (size_t)new_size );
 282         } else {
 283                 /*
 284                  * If the current buffer size is bigger than the space needed,
 285                  * just double it, else add extra_space. Always keep 64 bytes
 286                  * more, so that after we added a large blob we don't have to
 287                  * realloc immediately again.
 288                  */
 289                 new_size = MAX(ps->buffer_size*2,
 290                                ps->buffer_size + extra_space + 64);
 291
 292                 if ((ps->data_p = (char *)SMB_REALLOC(ps->data_p, new_size)) == NULL) {
 293                         DEBUG(0,("prs_grow: Realloc failure for size %u.\n",
 294                                 (unsigned int)new_size));
 295                         return False;
 296                 }
 297
 298                 memset(&ps->data_p[ps->buffer_size], '\0', (size_t)(new_size - ps->buffer_size));
 299         }
 300         ps->buffer_size = new_size;
 301
 302         return True;
 303 }
 304
 305 /*******************************************************************
 306  Attempt to force a data buffer to grow by len bytes.
 307  This is only used when appending more data onto a prs_struct
 308  when reading an rpc reply, before unmarshalling it.
 309  ********************************************************************/
 310
 311 bool prs_force_grow(prs_struct *ps, uint32 extra_space)
 312 {
 313         uint32 new_size = ps->buffer_size + extra_space;
 314
 315         if(!UNMARSHALLING(ps) || !ps->is_dynamic) {
 316                 DEBUG(0,("prs_force_grow: Buffer overflow - unable to expand buffer by %u bytes.\n",
 317                                 (unsigned int)extra_space));
 318                 return False;
 319         }
 320
 321         if((ps->data_p = (char *)SMB_REALLOC(ps->data_p, new_size)) == NULL) {
 322                 DEBUG(0,("prs_force_grow: Realloc failure for size %u.\n",
 323                         (unsigned int)new_size));
 324                 return False;
 325         }
 326
 327         memset(&ps->data_p[ps->buffer_size], '\0', (size_t)(new_size - ps->buffer_size));
 328
 329         ps->buffer_size = new_size;
 330
 331         return True;
 332 }
 333
 334 /*******************************************************************
 335  Get the data pointer (external interface).
 336 ********************************************************************/
 337
 338 char *prs_data_p(prs_struct *ps)
 339 {
 340         return ps->data_p;
 341 }
 342
 343 /*******************************************************************
 344  Get the current data size (external interface).
 345  ********************************************************************/
 346
 347 uint32 prs_data_size(prs_struct *ps)
 348 {
 349         return ps->buffer_size;
 350 }
 351
 352 /*******************************************************************
 353  Fetch the current offset (external interface).
 354  ********************************************************************/
 355
 356 uint32 prs_offset(prs_struct *ps)
 357 {
 358         return ps->data_offset;
 359 }
 360
 361 /*******************************************************************
 362  Set the current offset (external interface).
 363  ********************************************************************/
 364
 365 bool prs_set_offset(prs_struct *ps, uint32 offset)
 366 {
 367         if ((offset > ps->data_offset)
 368             && !prs_grow(ps, offset - ps->data_offset)) {
 369                 return False;
 370         }
 371
 372         ps->data_offset = offset;
 373         return True;
 374 }
 375
 376 /*******************************************************************
 377  Append the data from one parse_struct into another.
 378  ********************************************************************/
 379
 380 bool prs_append_prs_data(prs_struct *dst, prs_struct *src)
 381 {
 382         if (prs_offset(src) == 0)
 383                 return True;
 384
 385         if(!prs_grow(dst, prs_offset(src)))
 386                 return False;
 387
 388         memcpy(&dst->data_p[dst->data_offset], src->data_p, (size_t)prs_offset(src));
 389         dst->data_offset += prs_offset(src);
 390
 391         return True;
 392 }
 393
 394 /*******************************************************************
 395  Append some data from one parse_struct into another.
 396  ********************************************************************/
 397
 398 bool prs_append_some_data(prs_struct *dst, void *src_base, uint32_t start,
 399                           uint32_t len)
 400 {
 401         if (len == 0) {
 402                 return true;
 403         }
 404
 405         if(!prs_grow(dst, len)) {
 406                 return false;
 407         }
 408
 409         memcpy(&dst->data_p[dst->data_offset], ((char *)src_base) + start, (size_t)len);
 410         dst->data_offset += len;
 411         return true;
 412 }
 413
 414 bool prs_append_some_prs_data(prs_struct *dst, prs_struct *src, int32 start,
 415                               uint32 len)
 416 {
 417         return prs_append_some_data(dst, src->data_p, start, len);
 418 }
 419
 420 /*******************************************************************
 421  Append the data from a buffer into a parse_struct.
 422  ********************************************************************/
 423
 424 bool prs_copy_data_in(prs_struct *dst, const char *src, uint32 len)
 425 {
 426         if (len == 0)
 427                 return True;
 428
 429         if(!prs_grow(dst, len))
 430                 return False;
 431
 432         memcpy(&dst->data_p[dst->data_offset], src, (size_t)len);
 433         dst->data_offset += len;
 434
 435         return True;
 436 }
 437
 438 /*******************************************************************
 439  Copy some data from a parse_struct into a buffer.
 440  ********************************************************************/
 441
 442 bool prs_copy_data_out(char *dst, prs_struct *src, uint32 len)
 443 {
 444         if (len == 0)
 445                 return True;
 446
 447         if(!prs_mem_get(src, len))
 448                 return False;
 449
 450         memcpy(dst, &src->data_p[src->data_offset], (size_t)len);
 451         src->data_offset += len;
 452
 453         return True;
 454 }
 455
 456 /*******************************************************************
 457  Copy all the data from a parse_struct into a buffer.
 458  ********************************************************************/
 459
 460 bool prs_copy_all_data_out(char *dst, prs_struct *src)
 461 {
 462         uint32 len = prs_offset(src);
 463
 464         if (!len)
 465                 return True;
 466
 467         prs_set_offset(src, 0);
 468         return prs_copy_data_out(dst, src, len);
 469 }
 470
 471 /*******************************************************************
 472  Set the data as X-endian (external interface).
 473  ********************************************************************/
 474
 475 void prs_set_endian_data(prs_struct *ps, bool endian)
 476 {
 477         ps->bigendian_data = endian;
 478 }
 479
 480 /*******************************************************************
 481  Align a the data_len to a multiple of align bytes - filling with
 482  zeros.
 483  ********************************************************************/
 484
 485 bool prs_align(prs_struct *ps)
 486 {
 487         uint32 mod = ps->data_offset & (ps->align-1);
 488
 489         if (ps->align != 0 && mod != 0) {
 490                 uint32 extra_space = (ps->align - mod);
 491                 if(!prs_grow(ps, extra_space))
 492                         return False;
 493                 memset(&ps->data_p[ps->data_offset], '\0', (size_t)extra_space);
 494                 ps->data_offset += extra_space;
 495         }
 496
 497         return True;
 498 }
 499
 500 /******************************************************************
 501  Align on a 2 byte boundary
 502  *****************************************************************/
 503
 504 bool prs_align_uint16(prs_struct *ps)
 505 {
 506         bool ret;
 507         uint8 old_align = ps->align;
 508
 509         ps->align = 2;
 510         ret = prs_align(ps);
 511         ps->align = old_align;
 512
 513         return ret;
 514 }
 515
 516 /******************************************************************
 517  Align on a 8 byte boundary
 518  *****************************************************************/
 519
 520 bool prs_align_uint64(prs_struct *ps)
 521 {
 522         bool ret;
 523         uint8 old_align = ps->align;
 524
 525         ps->align = 8;
 526         ret = prs_align(ps);
 527         ps->align = old_align;
 528
 529         return ret;
 530 }
 531
 532 /******************************************************************
 533  Align on a specific byte boundary
 534  *****************************************************************/
 535
 536 bool prs_align_custom(prs_struct *ps, uint8 boundary)
 537 {
 538         bool ret;
 539         uint8 old_align = ps->align;
 540
 541         ps->align = boundary;
 542         ret = prs_align(ps);
 543         ps->align = old_align;
 544
 545         return ret;
 546 }
 547
 548
 549
 550 /*******************************************************************
 551  Align only if required (for the unistr2 string mainly)
 552  ********************************************************************/
 553
 554 bool prs_align_needed(prs_struct *ps, uint32 needed)
 555 {
 556         if (needed==0)
 557                 return True;
 558         else
 559                 return prs_align(ps);
 560 }
 561
 562 /*******************************************************************
 563  Ensure we can read/write to a given offset.
 564  ********************************************************************/
 565
 566 char *prs_mem_get(prs_struct *ps, uint32 extra_size)
 567 {
 568         if(UNMARSHALLING(ps)) {
 569                 /*
 570                  * If reading, ensure that we can read the requested size item.
 571                  */
 572                 if (ps->data_offset + extra_size > ps->buffer_size) {
 573                         DEBUG(0,("prs_mem_get: reading data of size %u would overrun "
 574                                 "buffer by %u bytes.\n",
 575                                 (unsigned int)extra_size,
 576                                 (unsigned int)(ps->data_offset + extra_size - ps->buffer_size) ));
 577                         return NULL;
 578                 }
 579         } else {
 580                 /*
 581                  * Writing - grow the buffer if needed.
 582                  */
 583                 if(!prs_grow(ps, extra_size))
 584                         return NULL;
 585         }
 586         return &ps->data_p[ps->data_offset];
 587 }
 588
 589 /*******************************************************************
 590  Change the struct type.
 591  ********************************************************************/
 592
 593 void prs_switch_type(prs_struct *ps, bool io)
 594 {
 595         if ((ps->io ^ io) == True)
 596                 ps->io=io;
 597 }
 598
 599 /*******************************************************************
 600  Force a prs_struct to be dynamic even when it's size is 0.
 601  ********************************************************************/
 602
 603 void prs_force_dynamic(prs_struct *ps)
 604 {
 605         ps->is_dynamic=True;
 606 }
 607
 608 /*******************************************************************
 609  Associate a session key with a parse struct.
 610  ********************************************************************/
 611
 612 void prs_set_session_key(prs_struct *ps, const char sess_key[16])
 613 {
 614         ps->sess_key = sess_key;
 615 }
 616
 617 /*******************************************************************
 618  Stream a uint8.
 619  ********************************************************************/
 620
 621 bool prs_uint8(const char *name, prs_struct *ps, int depth, uint8 *data8)
 622 {
 623         char *q = prs_mem_get(ps, 1);
 624         if (q == NULL)
 625                 return False;
 626
 627         if (UNMARSHALLING(ps))
 628                 *data8 = CVAL(q,0);
 629         else
 630                 SCVAL(q,0,*data8);
 631
 632         DEBUGADD(5,("%s%04x %s: %02x\n", tab_depth(5,depth), ps->data_offset, name, *data8));
 633
 634         ps->data_offset += 1;
 635
 636         return True;
 637 }
 638
 639 /*******************************************************************
 640  Stream a uint16.
 641  ********************************************************************/
 642
 643 bool prs_uint16(const char *name, prs_struct *ps, int depth, uint16 *data16)
 644 {
 645         char *q = prs_mem_get(ps, sizeof(uint16));
 646         if (q == NULL)
 647                 return False;
 648
 649         if (UNMARSHALLING(ps)) {
 650                 if (ps->bigendian_data)
 651                         *data16 = RSVAL(q,0);
 652                 else
 653                         *data16 = SVAL(q,0);
 654         } else {
 655                 if (ps->bigendian_data)
 656                         RSSVAL(q,0,*data16);
 657                 else
 658                         SSVAL(q,0,*data16);
 659         }
 660
 661         DEBUGADD(5,("%s%04x %s: %04x\n", tab_depth(5,depth), ps->data_offset, name, *data16));
 662
 663         ps->data_offset += sizeof(uint16);
 664
 665         return True;
 666 }
 667
 668 /*******************************************************************
 669  Stream a uint32.
 670  ********************************************************************/
 671
 672 bool prs_uint32(const char *name, prs_struct *ps, int depth, uint32 *data32)
 673 {
 674         char *q = prs_mem_get(ps, sizeof(uint32));
 675         if (q == NULL)
 676                 return False;
 677
 678         if (UNMARSHALLING(ps)) {
 679                 if (ps->bigendian_data)
 680                         *data32 = RIVAL(q,0);
 681                 else
 682                         *data32 = IVAL(q,0);
 683         } else {
 684                 if (ps->bigendian_data)
 685                         RSIVAL(q,0,*data32);
 686                 else
 687                         SIVAL(q,0,*data32);
 688         }
 689
 690         DEBUGADD(5,("%s%04x %s: %08x\n", tab_depth(5,depth), ps->data_offset, name, *data32));
 691
 692         ps->data_offset += sizeof(uint32);
 693
 694         return True;
 695 }
 696
 697 /*******************************************************************
 698  Stream an int32.
 699  ********************************************************************/
 700
 701 bool prs_int32(const char *name, prs_struct *ps, int depth, int32 *data32)
 702 {
 703         char *q = prs_mem_get(ps, sizeof(int32));
 704         if (q == NULL)
 705                 return False;
 706
 707         if (UNMARSHALLING(ps)) {
 708                 if (ps->bigendian_data)
 709                         *data32 = RIVALS(q,0);
 710                 else
 711                         *data32 = IVALS(q,0);
 712         } else {
 713                 if (ps->bigendian_data)
 714                         RSIVALS(q,0,*data32);
 715                 else
 716                         SIVALS(q,0,*data32);
 717         }
 718
 719         DEBUGADD(5,("%s%04x %s: %08x\n", tab_depth(5,depth), ps->data_offset, name, *data32));
 720
 721         ps->data_offset += sizeof(int32);
 722
 723         return True;
 724 }
 725
 726 /*******************************************************************
 727  Stream a uint64_struct
 728  ********************************************************************/
 729 bool prs_uint64(const char *name, prs_struct *ps, int depth, uint64 *data64)
 730 {
 731         if (UNMARSHALLING(ps)) {
 732                 uint32 high, low;
 733
 734                 if (!prs_uint32(name, ps, depth+1, &low))
 735                         return False;
 736
 737                 if (!prs_uint32(name, ps, depth+1, &high))
 738                         return False;
 739
 740                 *data64 = ((uint64_t)high << 32) + low;
 741
 742                 return True;
 743         } else {
 744                 uint32 high = (*data64) >> 32, low = (*data64) & 0xFFFFFFFF;
 745                 return prs_uint32(name, ps, depth+1, &low) &&
 746                            prs_uint32(name, ps, depth+1, &high);
 747         }
 748 }
 749
 750 /*******************************************************************
 751  Stream a DCE error code
 752  ********************************************************************/
 753
 754 bool prs_dcerpc_status(const char *name, prs_struct *ps, int depth, NTSTATUS *status)
 755 {
 756         char *q = prs_mem_get(ps, sizeof(uint32));
 757         if (q == NULL)
 758                 return False;
 759
 760         if (UNMARSHALLING(ps)) {
 761                 if (ps->bigendian_data)
 762                         *status = NT_STATUS(RIVAL(q,0));
 763                 else
 764                         *status = NT_STATUS(IVAL(q,0));
 765         } else {
 766                 if (ps->bigendian_data)
 767                         RSIVAL(q,0,NT_STATUS_V(*status));
 768                 else
 769                         SIVAL(q,0,NT_STATUS_V(*status));
 770         }
 771
 772         DEBUGADD(5,("%s%04x %s: %s\n", tab_depth(5,depth), ps->data_offset, name,
 773                  dcerpc_errstr(debug_ctx(), NT_STATUS_V(*status))));
 774
 775         ps->data_offset += sizeof(uint32);
 776
 777         return True;
 778 }
 779
 780 /******************************************************************
 781  Stream an array of uint8s. Length is number of uint8s.
 782  ********************************************************************/
 783
 784 bool prs_uint8s(bool charmode, const char *name, prs_struct *ps, int depth, uint8 *data8s, int len)
 785 {
 786         int i;
 787         char *q = prs_mem_get(ps, len);
 788         if (q == NULL)
 789                 return False;
 790
 791         if (UNMARSHALLING(ps)) {
 792                 for (i = 0; i < len; i++)
 793                         data8s[i] = CVAL(q,i);
 794         } else {
 795                 for (i = 0; i < len; i++)
 796                         SCVAL(q, i, data8s[i]);
 797         }
 798
 799         DEBUGADD(5,("%s%04x %s: ", tab_depth(5,depth), ps->data_offset ,name));
 800         if (charmode)
 801                 print_asc(5, (unsigned char*)data8s, len);
 802         else {
 803                 for (i = 0; i < len; i++)
 804                         DEBUGADD(5,("%02x ", data8s[i]));
 805         }
 806         DEBUGADD(5,("\n"));
 807
 808         ps->data_offset += len;
 809
 810         return True;
 811 }
 812
 813 /******************************************************************
 814  Stream an array of uint16s. Length is number of uint16s.
 815  ********************************************************************/
 816
 817 bool prs_uint16s(bool charmode, const char *name, prs_struct *ps, int depth, uint16 *data16s, int len)
 818 {
 819         int i;
 820         char *q = prs_mem_get(ps, len * sizeof(uint16));
 821         if (q == NULL)
 822                 return False;
 823
 824         if (UNMARSHALLING(ps)) {
 825                 if (ps->bigendian_data) {
 826                         for (i = 0; i < len; i++)
 827                                 data16s[i] = RSVAL(q, 2*i);
 828                 } else {
 829                         for (i = 0; i < len; i++)
 830                                 data16s[i] = SVAL(q, 2*i);
 831                 }
 832         } else {
 833                 if (ps->bigendian_data) {
 834                         for (i = 0; i < len; i++)
 835                                 RSSVAL(q, 2*i, data16s[i]);
 836                 } else {
 837                         for (i = 0; i < len; i++)
 838                                 SSVAL(q, 2*i, data16s[i]);
 839                 }
 840         }
 841
 842         DEBUGADD(5,("%s%04x %s: ", tab_depth(5,depth), ps->data_offset, name));
 843         if (charmode)
 844                 print_asc(5, (unsigned char*)data16s, 2*len);
 845         else {
 846                 for (i = 0; i < len; i++)
 847                         DEBUGADD(5,("%04x ", data16s[i]));
 848         }
 849         DEBUGADD(5,("\n"));
 850
 851         ps->data_offset += (len * sizeof(uint16));
 852
 853         return True;
 854 }
 855
 856 /******************************************************************
 857  Stream an array of uint32s. Length is number of uint32s.
 858  ********************************************************************/
 859
 860 bool prs_uint32s(bool charmode, const char *name, prs_struct *ps, int depth, uint32 *data32s, int len)
 861 {
 862         int i;
 863         char *q = prs_mem_get(ps, len * sizeof(uint32));
 864         if (q == NULL)
 865                 return False;
 866
 867         if (UNMARSHALLING(ps)) {
 868                 if (ps->bigendian_data) {
 869                         for (i = 0; i < len; i++)
 870                                 data32s[i] = RIVAL(q, 4*i);
 871                 } else {
 872                         for (i = 0; i < len; i++)
 873                                 data32s[i] = IVAL(q, 4*i);
 874                 }
 875         } else {
 876                 if (ps->bigendian_data) {
 877                         for (i = 0; i < len; i++)
 878                                 RSIVAL(q, 4*i, data32s[i]);
 879                 } else {
 880                         for (i = 0; i < len; i++)
 881                                 SIVAL(q, 4*i, data32s[i]);
 882                 }
 883         }
 884
 885         DEBUGADD(5,("%s%04x %s: ", tab_depth(5,depth), ps->data_offset, name));
 886         if (charmode)
 887                 print_asc(5, (unsigned char*)data32s, 4*len);
 888         else {
 889                 for (i = 0; i < len; i++)
 890                         DEBUGADD(5,("%08x ", data32s[i]));
 891         }
 892         DEBUGADD(5,("\n"));
 893
 894         ps->data_offset += (len * sizeof(uint32));
 895
 896         return True;
 897 }
 898
 899 /*******************************************************************
 900  Stream a unicode  null-terminated string. As the string is already
 901  in little-endian format then do it as a stream of bytes.
 902  ********************************************************************/
 903
 904 bool prs_unistr(const char *name, prs_struct *ps, int depth, UNISTR *str)
 905 {
 906         unsigned int len = 0;
 907         unsigned char *p = (unsigned char *)str->buffer;
 908         uint8 *start;
 909         char *q;
 910         uint32 max_len;
 911         uint16* ptr;
 912
 913         if (MARSHALLING(ps)) {
 914
 915                 for(len = 0; str->buffer[len] != 0; len++)
 916                         ;
 917
 918                 q = prs_mem_get(ps, (len+1)*2);
 919                 if (q == NULL)
 920                         return False;
 921
 922                 start = (uint8*)q;
 923
 924                 for(len = 0; str->buffer[len] != 0; len++) {
 925                         if(ps->bigendian_data) {
 926                                 /* swap bytes - p is little endian, q is big endian. */
 927                                 q[0] = (char)p[1];
 928                                 q[1] = (char)p[0];
 929                                 p += 2;
 930                                 q += 2;
 931                         }
 932                         else
 933                         {
 934                                 q[0] = (char)p[0];
 935                                 q[1] = (char)p[1];
 936                                 p += 2;
 937                                 q += 2;
 938                         }
 939                 }
 940
 941                 /*
 942                  * even if the string is 'empty' (only an \0 char)
 943                  * at this point the leading \0 hasn't been parsed.
 944                  * so parse it now
 945                  */
 946
 947                 q[0] = 0;
 948                 q[1] = 0;
 949                 q += 2;
 950
 951                 len++;
 952
 953                 DEBUGADD(5,("%s%04x %s: ", tab_depth(5,depth), ps->data_offset, name));
 954                 print_asc(5, (unsigned char*)start, 2*len);
 955                 DEBUGADD(5, ("\n"));
 956         }
 957         else { /* unmarshalling */
 958
 959                 uint32 alloc_len = 0;
 960                 q = ps->data_p + prs_offset(ps);
 961
 962                 /*
 963                  * Work out how much space we need and talloc it.
 964                  */
 965                 max_len = (ps->buffer_size - ps->data_offset)/sizeof(uint16);
 966
 967                 /* the test of the value of *ptr helps to catch the circumstance
 968                    where we have an emtpty (non-existent) string in the buffer */
 969                 for ( ptr = (uint16 *)q; *ptr++ && (alloc_len <= max_len); alloc_len++)
 970                         /* do nothing */
 971                         ;
 972
 973                 if (alloc_len < max_len)
 974                         alloc_len += 1;
 975
 976                 /* should we allocate anything at all? */
 977                 str->buffer = PRS_ALLOC_MEM(ps,uint16,alloc_len);
 978                 if ((str->buffer == NULL) && (alloc_len > 0))
 979                         return False;
 980
 981                 p = (unsigned char *)str->buffer;
 982
 983                 len = 0;
 984                 /* the (len < alloc_len) test is to prevent us from overwriting
 985                    memory that is not ours...if we get that far, we have a non-null
 986                    terminated string in the buffer and have messed up somewhere */
 987                 while ((len < alloc_len) && (*(uint16 *)q != 0)) {
 988                         if(ps->bigendian_data)
 989                         {
 990                                 /* swap bytes - q is big endian, p is little endian. */
 991                                 p[0] = (unsigned char)q[1];
 992                                 p[1] = (unsigned char)q[0];
 993                                 p += 2;
 994                                 q += 2;
 995                         } else {
 996
 997                                 p[0] = (unsigned char)q[0];
 998                                 p[1] = (unsigned char)q[1];
 999                                 p += 2;
1000                                 q += 2;
1001                         }
1002
1003                         len++;
1004                 }
1005                 if (len < alloc_len) {
1006                         /* NULL terminate the UNISTR */
1007                         str->buffer[len++] = '\0';
1008                 }
1009
1010                 DEBUGADD(5,("%s%04x %s: ", tab_depth(5,depth), ps->data_offset, name));
1011                 print_asc(5, (unsigned char*)str->buffer, 2*len);
1012                 DEBUGADD(5, ("\n"));
1013         }
1014
1015         /* set the offset in the prs_struct; 'len' points to the
1016            terminiating NULL in the UNISTR so we need to go one more
1017            uint16 */
1018         ps->data_offset += (len)*2;
1019
1020         return True;
1021 }
1022
1023
1024 /*******************************************************************
1025  Stream a null-terminated string.  len is strlen, and therefore does
1026  not include the null-termination character.
1027  ********************************************************************/
1028
1029 bool prs_string(const char *name, prs_struct *ps, int depth, char *str, int max_buf_size)
1030 {
1031         char *q;
1032         int i;
1033         int len;
1034
1035         if (UNMARSHALLING(ps))
1036                 len = strlen(&ps->data_p[ps->data_offset]);
1037         else
1038                 len = strlen(str);
1039
1040         len = MIN(len, (max_buf_size-1));
1041
1042         q = prs_mem_get(ps, len+1);
1043         if (q == NULL)
1044                 return False;
1045
1046         for(i = 0; i < len; i++) {
1047                 if (UNMARSHALLING(ps))
1048                         str[i] = q[i];
1049                 else
1050                         q[i] = str[i];
1051         }
1052
1053         /* The terminating null. */
1054         str[i] = '\0';
1055
1056         if (MARSHALLING(ps)) {
1057                 q[i] = '\0';
1058         }
1059
1060         ps->data_offset += len+1;
1061
1062         dump_data(5+depth, (uint8 *)q, len);
1063
1064         return True;
1065 }
1066
1067 /*******************************************************************
1068  Create a digest over the entire packet (including the data), and
1069  MD5 it with the session key.
1070  ********************************************************************/
1071
1072 static void schannel_digest(struct schannel_auth_struct *a,
1073                           enum pipe_auth_level auth_level,
1074                           RPC_AUTH_SCHANNEL_CHK * verf,
1075                           char *data, size_t data_len,
1076                           uchar digest_final[16])
1077 {
1078         uchar whole_packet_digest[16];
1079         uchar zeros[4];
1080         struct MD5Context ctx3;
1081
1082         ZERO_STRUCT(zeros);
1083
1084         /* verfiy the signature on the packet by MD5 over various bits */
1085         MD5Init(&ctx3);
1086         /* use our sequence number, which ensures the packet is not
1087            out of order */
1088         MD5Update(&ctx3, zeros, sizeof(zeros));
1089         MD5Update(&ctx3, verf->sig, sizeof(verf->sig));
1090         if (auth_level == PIPE_AUTH_LEVEL_PRIVACY) {
1091                 MD5Update(&ctx3, verf->confounder, sizeof(verf->confounder));
1092         }
1093         MD5Update(&ctx3, (const unsigned char *)data, data_len);
1094         MD5Final(whole_packet_digest, &ctx3);
1095         dump_data_pw("whole_packet_digest:\n", whole_packet_digest, sizeof(whole_packet_digest));
1096
1097         /* MD5 this result and the session key, to prove that
1098            only a valid client could had produced this */
1099         hmac_md5(a->sess_key, whole_packet_digest, sizeof(whole_packet_digest), digest_final);
1100 }
1101
1102 /*******************************************************************
1103  Calculate the key with which to encode the data payload
1104  ********************************************************************/
1105
1106 static void schannel_get_sealing_key(struct schannel_auth_struct *a,
1107                                    RPC_AUTH_SCHANNEL_CHK *verf,
1108                                    uchar sealing_key[16])
1109 {
1110         uchar zeros[4];
1111         uchar digest2[16];
1112         uchar sess_kf0[16];
1113         int i;
1114
1115         ZERO_STRUCT(zeros);
1116
1117         for (i = 0; i < sizeof(sess_kf0); i++) {
1118                 sess_kf0[i] = a->sess_key[i] ^ 0xf0;
1119         }
1120
1121         dump_data_pw("sess_kf0:\n", sess_kf0, sizeof(sess_kf0));
1122
1123         /* MD5 of sess_kf0 and 4 zero bytes */
1124         hmac_md5(sess_kf0, zeros, 0x4, digest2);
1125         dump_data_pw("digest2:\n", digest2, sizeof(digest2));
1126
1127         /* MD5 of the above result, plus 8 bytes of sequence number */
1128         hmac_md5(digest2, verf->seq_num, sizeof(verf->seq_num), sealing_key);
1129         dump_data_pw("sealing_key:\n", sealing_key, 16);
1130 }
1131
1132 /*******************************************************************
1133  Encode or Decode the sequence number (which is symmetric)
1134  ********************************************************************/
1135
1136 static void schannel_deal_with_seq_num(struct schannel_auth_struct *a,
1137                                      RPC_AUTH_SCHANNEL_CHK *verf)
1138 {
1139         uchar zeros[4];
1140         uchar sequence_key[16];
1141         uchar digest1[16];
1142
1143         ZERO_STRUCT(zeros);
1144
1145         hmac_md5(a->sess_key, zeros, sizeof(zeros), digest1);
1146         dump_data_pw("(sequence key) digest1:\n", digest1, sizeof(digest1));
1147
1148         hmac_md5(digest1, verf->packet_digest, 8, sequence_key);
1149
1150         dump_data_pw("sequence_key:\n", sequence_key, sizeof(sequence_key));
1151
1152         dump_data_pw("seq_num (before):\n", verf->seq_num, sizeof(verf->seq_num));
1153         arcfour_crypt(verf->seq_num, sequence_key, 8);
1154         dump_data_pw("seq_num (after):\n", verf->seq_num, sizeof(verf->seq_num));
1155 }
1156
1157 /*******************************************************************
1158 creates an RPC_AUTH_SCHANNEL_CHK structure.
1159 ********************************************************************/
1160
1161 static bool init_rpc_auth_schannel_chk(RPC_AUTH_SCHANNEL_CHK * chk,
1162                               const uchar sig[8],
1163                               const uchar packet_digest[8],
1164                               const uchar seq_num[8], const uchar confounder[8])
1165 {
1166         if (chk == NULL)
1167                 return False;
1168
1169         memcpy(chk->sig, sig, sizeof(chk->sig));
1170         memcpy(chk->packet_digest, packet_digest, sizeof(chk->packet_digest));
1171         memcpy(chk->seq_num, seq_num, sizeof(chk->seq_num));
1172         memcpy(chk->confounder, confounder, sizeof(chk->confounder));
1173
1174         return True;
1175 }
1176
1177 /*******************************************************************
1178  Encode a blob of data using the schannel alogrithm, also produceing
1179  a checksum over the original data.  We currently only support
1180  signing and sealing togeather - the signing-only code is close, but not
1181  quite compatible with what MS does.
1182  ********************************************************************/
1183
1184 void schannel_encode(struct schannel_auth_struct *a, enum pipe_auth_level auth_level,
1185                    enum schannel_direction direction,
1186                    RPC_AUTH_SCHANNEL_CHK * verf,
1187                    char *data, size_t data_len)
1188 {
1189         uchar digest_final[16];
1190         uchar confounder[8];
1191         uchar seq_num[8];
1192         static const uchar nullbytes[8] = { 0, };
1193
1194         static const uchar schannel_seal_sig[8] = SCHANNEL_SEAL_SIGNATURE;
1195         static const uchar schannel_sign_sig[8] = SCHANNEL_SIGN_SIGNATURE;
1196         const uchar *schannel_sig = NULL;
1197
1198         DEBUG(10,("SCHANNEL: schannel_encode seq_num=%d data_len=%lu\n", a->seq_num, (unsigned long)data_len));
1199
1200         if (auth_level == PIPE_AUTH_LEVEL_PRIVACY) {
1201                 schannel_sig = schannel_seal_sig;
1202         } else {
1203                 schannel_sig = schannel_sign_sig;
1204         }
1205
1206         /* fill the 'confounder' with random data */
1207         generate_random_buffer(confounder, sizeof(confounder));
1208
1209         dump_data_pw("a->sess_key:\n", a->sess_key, sizeof(a->sess_key));
1210
1211         RSIVAL(seq_num, 0, a->seq_num);
1212
1213         switch (direction) {
1214         case SENDER_IS_INITIATOR:
1215                 SIVAL(seq_num, 4, 0x80);
1216                 break;
1217         case SENDER_IS_ACCEPTOR:
1218                 SIVAL(seq_num, 4, 0x0);
1219                 break;
1220         }
1221
1222         dump_data_pw("verf->seq_num:\n", seq_num, sizeof(verf->seq_num));
1223
1224         init_rpc_auth_schannel_chk(verf, schannel_sig, nullbytes,
1225                                  seq_num, confounder);
1226
1227         /* produce a digest of the packet to prove it's legit (before we seal it) */
1228         schannel_digest(a, auth_level, verf, data, data_len, digest_final);
1229         memcpy(verf->packet_digest, digest_final, sizeof(verf->packet_digest));
1230
1231         if (auth_level == PIPE_AUTH_LEVEL_PRIVACY) {
1232                 uchar sealing_key[16];
1233
1234                 /* get the key to encode the data with */
1235                 schannel_get_sealing_key(a, verf, sealing_key);
1236
1237                 /* encode the verification data */
1238                 dump_data_pw("verf->confounder:\n", verf->confounder, sizeof(verf->confounder));
1239                 arcfour_crypt(verf->confounder, sealing_key, 8);
1240
1241                 dump_data_pw("verf->confounder_enc:\n", verf->confounder, sizeof(verf->confounder));
1242
1243                 /* encode the packet payload */
1244                 dump_data_pw("data:\n", (const unsigned char *)data, data_len);
1245                 arcfour_crypt((unsigned char *)data, sealing_key, data_len);
1246                 dump_data_pw("data_enc:\n", (const unsigned char *)data, data_len);
1247         }
1248
1249         /* encode the sequence number (key based on packet digest) */
1250         /* needs to be done after the sealing, as the original version
1251            is used in the sealing stuff... */
1252         schannel_deal_with_seq_num(a, verf);
1253
1254         return;
1255 }
1256
1257 /*******************************************************************
1258  Decode a blob of data using the schannel alogrithm, also verifiying
1259  a checksum over the original data.  We currently can verify signed messages,
1260  as well as decode sealed messages
1261  ********************************************************************/
1262
1263 bool schannel_decode(struct schannel_auth_struct *a, enum pipe_auth_level auth_level,
1264                    enum schannel_direction direction,
1265                    RPC_AUTH_SCHANNEL_CHK * verf, char *data, size_t data_len)
1266 {
1267         uchar digest_final[16];
1268
1269         static const uchar schannel_seal_sig[8] = SCHANNEL_SEAL_SIGNATURE;
1270         static const uchar schannel_sign_sig[8] = SCHANNEL_SIGN_SIGNATURE;
1271         const uchar *schannel_sig = NULL;
1272
1273         uchar seq_num[8];
1274
1275         DEBUG(10,("SCHANNEL: schannel_decode seq_num=%d data_len=%lu\n", a->seq_num, (unsigned long)data_len));
1276
1277         if (auth_level == PIPE_AUTH_LEVEL_PRIVACY) {
1278                 schannel_sig = schannel_seal_sig;
1279         } else {
1280                 schannel_sig = schannel_sign_sig;
1281         }
1282
1283         /* Create the expected sequence number for comparison */
1284         RSIVAL(seq_num, 0, a->seq_num);
1285
1286         switch (direction) {
1287         case SENDER_IS_INITIATOR:
1288                 SIVAL(seq_num, 4, 0x80);
1289                 break;
1290         case SENDER_IS_ACCEPTOR:
1291                 SIVAL(seq_num, 4, 0x0);
1292                 break;
1293         }
1294
1295         DEBUG(10,("SCHANNEL: schannel_decode seq_num=%d data_len=%lu\n", a->seq_num, (unsigned long)data_len));
1296         dump_data_pw("a->sess_key:\n", a->sess_key, sizeof(a->sess_key));
1297
1298         dump_data_pw("seq_num:\n", seq_num, sizeof(seq_num));
1299
1300         /* extract the sequence number (key based on supplied packet digest) */
1301         /* needs to be done before the sealing, as the original version
1302            is used in the sealing stuff... */
1303         schannel_deal_with_seq_num(a, verf);
1304
1305         if (memcmp(verf->seq_num, seq_num, sizeof(seq_num))) {
1306                 /* don't even bother with the below if the sequence number is out */
1307                 /* The sequence number is MD5'ed with a key based on the whole-packet
1308                    digest, as supplied by the client.  We check that it's a valid
1309                    checksum after the decode, below
1310                 */
1311                 DEBUG(2, ("schannel_decode: FAILED: packet sequence number:\n"));
1312                 dump_data(2, verf->seq_num, sizeof(verf->seq_num));
1313                 DEBUG(2, ("should be:\n"));
1314                 dump_data(2, seq_num, sizeof(seq_num));
1315
1316                 return False;
1317         }
1318
1319         if (memcmp(verf->sig, schannel_sig, sizeof(verf->sig))) {
1320                 /* Validate that the other end sent the expected header */
1321                 DEBUG(2, ("schannel_decode: FAILED: packet header:\n"));
1322                 dump_data(2, verf->sig, sizeof(verf->sig));
1323                 DEBUG(2, ("should be:\n"));
1324                 dump_data(2, schannel_sig, sizeof(schannel_sig));
1325                 return False;
1326         }
1327
1328         if (auth_level == PIPE_AUTH_LEVEL_PRIVACY) {
1329                 uchar sealing_key[16];
1330
1331                 /* get the key to extract the data with */
1332                 schannel_get_sealing_key(a, verf, sealing_key);
1333
1334                 /* extract the verification data */
1335                 dump_data_pw("verf->confounder:\n", verf->confounder,
1336                              sizeof(verf->confounder));
1337                 arcfour_crypt(verf->confounder, sealing_key, 8);
1338
1339                 dump_data_pw("verf->confounder_dec:\n", verf->confounder,
1340                              sizeof(verf->confounder));
1341
1342                 /* extract the packet payload */
1343                 dump_data_pw("data   :\n", (const unsigned char *)data, data_len);
1344                 arcfour_crypt((unsigned char *)data, sealing_key, data_len);
1345                 dump_data_pw("datadec:\n", (const unsigned char *)data, data_len);
1346         }
1347
1348         /* digest includes 'data' after unsealing */
1349         schannel_digest(a, auth_level, verf, data, data_len, digest_final);
1350
1351         dump_data_pw("Calculated digest:\n", digest_final,
1352                      sizeof(digest_final));
1353         dump_data_pw("verf->packet_digest:\n", verf->packet_digest,
1354                      sizeof(verf->packet_digest));
1355
1356         /* compare - if the client got the same result as us, then
1357            it must know the session key */
1358         return (memcmp(digest_final, verf->packet_digest,
1359                        sizeof(verf->packet_digest)) == 0);
1360 }
1361
1362 /*******************************************************************
1363 creates a new prs_struct containing a DATA_BLOB
1364 ********************************************************************/
1365 bool prs_init_data_blob(prs_struct *prs, DATA_BLOB *blob, TALLOC_CTX *mem_ctx)
1366 {
1367         if (!prs_init( prs, RPC_MAX_PDU_FRAG_LEN, mem_ctx, MARSHALL ))
1368                 return False;
1369
1370
1371         if (!prs_copy_data_in(prs, (char *)blob->data, blob->length))
1372                 return False;
1373
1374         return True;
1375 }
1376
1377 /*******************************************************************
1378 return the contents of a prs_struct in a DATA_BLOB
1379 ********************************************************************/
1380 bool prs_data_blob(prs_struct *prs, DATA_BLOB *blob, TALLOC_CTX *mem_ctx)
1381 {
1382         blob->length = prs_data_size(prs);
1383         blob->data = (uint8 *)TALLOC_ZERO_SIZE(mem_ctx, blob->length);
1384
1385         /* set the pointer at the end of the buffer */
1386         prs_set_offset( prs, prs_data_size(prs) );
1387
1388         if (!prs_copy_all_data_out((char *)blob->data, prs))
1389                 return False;
1390
1391         return True;
1392 }