source3/libsmb/ntlmssp_parse.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    simple kerberos5/SPNEGO routines
   4    Copyright (C) Andrew Tridgell 2001
   5    Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2002
   6    Copyright (C) Andrew Bartlett 2002-2003
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22
  23 #include "includes.h"
  24
  25 /*
  26   this is a tiny msrpc packet generator. I am only using this to
  27   avoid tying this code to a particular varient of our rpc code. This
  28   generator is not general enough for all our rpc needs, its just
  29   enough for the spnego/ntlmssp code
  30
  31   format specifiers are:
  32
  33   U = unicode string (input is unix string)
  34   a = address (input is BOOL unicode, char *unix_string)
  35       (1 byte type, 1 byte length, unicode/ASCII string, all inline)
  36   A = ASCII string (input is unix string)
  37   B = data blob (pointer + length)
  38   b = data blob in header (pointer + length)
  39   D
  40   d = word (4 bytes)
  41   C = constant ascii string
  42  */
  43 BOOL msrpc_gen(DATA_BLOB *blob,
  44                const char *format, ...)
  45 {
  46         int i, n;
  47         va_list ap;
  48         char *s;
  49         uint8 *b;
  50         int head_size=0, data_size=0;
  51         int head_ofs, data_ofs;
  52         BOOL unicode;
  53
  54         /* first scan the format to work out the header and body size */
  55         va_start(ap, format);
  56         for (i=0; format[i]; i++) {
  57                 switch (format[i]) {
  58                 case 'U':
  59                         s = va_arg(ap, char *);
  60                         head_size += 8;
  61                         data_size += str_charnum(s) * 2;
  62                         break;
  63                 case 'A':
  64                         s = va_arg(ap, char *);
  65                         head_size += 8;
  66                         data_size += str_ascii_charnum(s);
  67                         break;
  68                 case 'a':
  69                         unicode = va_arg(ap, BOOL);
  70                         n = va_arg(ap, int);
  71                         s = va_arg(ap, char *);
  72                         if (unicode) {
  73                                 data_size += (str_charnum(s) * 2) + 4;
  74                         } else {
  75                                 data_size += (str_ascii_charnum(s)) + 4;
  76                         }
  77                         break;
  78                 case 'B':
  79                         b = va_arg(ap, uint8 *);
  80                         head_size += 8;
  81                         data_size += va_arg(ap, int);
  82                         break;
  83                 case 'b':
  84                         b = va_arg(ap, uint8 *);
  85                         head_size += va_arg(ap, int);
  86                         break;
  87                 case 'd':
  88                         n = va_arg(ap, int);
  89                         head_size += 4;
  90                         break;
  91                 case 'C':
  92                         s = va_arg(ap, char *);
  93                         head_size += str_charnum(s) + 1;
  94                         break;
  95                 }
  96         }
  97         va_end(ap);
  98
  99         /* allocate the space, then scan the format again to fill in the values */
 100         *blob = data_blob(NULL, head_size + data_size);
 101
 102         head_ofs = 0;
 103         data_ofs = head_size;
 104
 105         va_start(ap, format);
 106         for (i=0; format[i]; i++) {
 107                 switch (format[i]) {
 108                 case 'U':
 109                         s = va_arg(ap, char *);
 110                         n = str_charnum(s);
 111                         SSVAL(blob->data, head_ofs, n*2); head_ofs += 2;
 112                         SSVAL(blob->data, head_ofs, n*2); head_ofs += 2;
 113                         SIVAL(blob->data, head_ofs, data_ofs); head_ofs += 4;
 114                         push_string(NULL, blob->data+data_ofs, s, n*2, STR_UNICODE|STR_NOALIGN);
 115                         data_ofs += n*2;
 116                         break;
 117                 case 'A':
 118                         s = va_arg(ap, char *);
 119                         n = str_ascii_charnum(s);
 120                         SSVAL(blob->data, head_ofs, n); head_ofs += 2;
 121                         SSVAL(blob->data, head_ofs, n); head_ofs += 2;
 122                         SIVAL(blob->data, head_ofs, data_ofs); head_ofs += 4;
 123                         push_string(NULL, blob->data+data_ofs, s, n, STR_ASCII|STR_NOALIGN);
 124                         data_ofs += n;
 125                         break;
 126                 case 'a':
 127                         unicode = va_arg(ap, BOOL);
 128                         n = va_arg(ap, int);
 129                         SSVAL(blob->data, data_ofs, n); data_ofs += 2;
 130                         s = va_arg(ap, char *);
 131                         if (unicode) {
 132                                 n = str_charnum(s);
 133                                 SSVAL(blob->data, data_ofs, n*2); data_ofs += 2;
 134                                 if (0 < n) {
 135                                         push_string(NULL, blob->data+data_ofs, s, n*2,
 136                                                     STR_UNICODE|STR_NOALIGN);
 137                                 }
 138                                 data_ofs += n*2;
 139                         } else {
 140                                 n = str_ascii_charnum(s);
 141                                 SSVAL(blob->data, data_ofs, n); data_ofs += 2;
 142                                 if (0 < n) {
 143                                         push_string(NULL, blob->data+data_ofs, s, n,
 144                                                     STR_ASCII|STR_NOALIGN);
 145                                 }
 146                                 data_ofs += n;
 147                         }
 148                         break;
 149
 150                 case 'B':
 151                         b = va_arg(ap, uint8 *);
 152                         n = va_arg(ap, int);
 153                         SSVAL(blob->data, head_ofs, n); head_ofs += 2;
 154                         SSVAL(blob->data, head_ofs, n); head_ofs += 2;
 155                         SIVAL(blob->data, head_ofs, data_ofs); head_ofs += 4;
 156                         if (n && b) /* don't follow null pointers... */
 157                                 memcpy(blob->data+data_ofs, b, n);
 158                         data_ofs += n;
 159                         break;
 160                 case 'd':
 161                         n = va_arg(ap, int);
 162                         SIVAL(blob->data, head_ofs, n); head_ofs += 4;
 163                         break;
 164                 case 'b':
 165                         b = va_arg(ap, uint8 *);
 166                         n = va_arg(ap, int);
 167                         memcpy(blob->data + head_ofs, b, n);
 168                         head_ofs += n;
 169                         break;
 170                 case 'C':
 171                         s = va_arg(ap, char *);
 172                         head_ofs += push_string(NULL, blob->data+head_ofs, s, -1,
 173                                                 STR_ASCII|STR_TERMINATE);
 174                         break;
 175                 }
 176         }
 177         va_end(ap);
 178
 179         return True;
 180 }
 181
 182
 183 /* a helpful macro to avoid running over the end of our blob */
 184 #define NEED_DATA(amount) \
 185 if ((head_ofs + amount) > blob->length) { \
 186         return False; \
 187 }
 188
 189 /*
 190   this is a tiny msrpc packet parser. This the the partner of msrpc_gen
 191
 192   format specifiers are:
 193
 194   U = unicode string (output is unix string)
 195   A = ascii string
 196   B = data blob
 197   b = data blob in header
 198   d = word (4 bytes)
 199   C = constant ascii string
 200  */
 201
 202 BOOL msrpc_parse(const DATA_BLOB *blob,
 203                  const char *format, ...)
 204 {
 205         int i;
 206         va_list ap;
 207         char **ps, *s;
 208         DATA_BLOB *b;
 209         size_t head_ofs = 0;
 210         uint16 len1, len2;
 211         uint32 ptr;
 212         uint32 *v;
 213         pstring p;
 214
 215         va_start(ap, format);
 216         for (i=0; format[i]; i++) {
 217                 switch (format[i]) {
 218                 case 'U':
 219                         NEED_DATA(8);
 220                         len1 = SVAL(blob->data, head_ofs); head_ofs += 2;
 221                         len2 = SVAL(blob->data, head_ofs); head_ofs += 2;
 222                         ptr =  IVAL(blob->data, head_ofs); head_ofs += 4;
 223
 224                         ps = va_arg(ap, char **);
 225                         if (len1 == 0 && len2 == 0) {
 226                                 *ps = smb_xstrdup("");
 227                         } else {
 228                                 /* make sure its in the right format - be strict */
 229                                 if ((len1 != len2) || (ptr + len1 < ptr) || (ptr + len1 < len1) || (ptr + len1 > blob->length)) {
 230                                         return False;
 231                                 }
 232                                 if (len1 & 1) {
 233                                         /* if odd length and unicode */
 234                                         return False;
 235                                 }
 236
 237                                 if (0 < len1) {
 238                                         pull_string(NULL, p, blob->data + ptr, sizeof(p),
 239                                                     len1,
 240                                                     STR_UNICODE|STR_NOALIGN);
 241                                         (*ps) = smb_xstrdup(p);
 242                                 } else {
 243                                         (*ps) = smb_xstrdup("");
 244                                 }
 245                         }
 246                         break;
 247                 case 'A':
 248                         NEED_DATA(8);
 249                         len1 = SVAL(blob->data, head_ofs); head_ofs += 2;
 250                         len2 = SVAL(blob->data, head_ofs); head_ofs += 2;
 251                         ptr =  IVAL(blob->data, head_ofs); head_ofs += 4;
 252
 253                         ps = va_arg(ap, char **);
 254                         /* make sure its in the right format - be strict */
 255                         if (len1 == 0 && len2 == 0) {
 256                                 *ps = smb_xstrdup("");
 257                         } else {
 258                                 if ((len1 != len2) || (ptr + len1 < ptr) || (ptr + len1 < len1) || (ptr + len1 > blob->length)) {
 259                                         return False;
 260                                 }
 261
 262                                 if (0 < len1) {
 263                                         pull_string(NULL, p, blob->data + ptr, sizeof(p),
 264                                                     len1,
 265                                                     STR_ASCII|STR_NOALIGN);
 266                                         (*ps) = smb_xstrdup(p);
 267                                 } else {
 268                                         (*ps) = smb_xstrdup("");
 269                                 }
 270                         }
 271                         break;
 272                 case 'B':
 273                         NEED_DATA(8);
 274                         len1 = SVAL(blob->data, head_ofs); head_ofs += 2;
 275                         len2 = SVAL(blob->data, head_ofs); head_ofs += 2;
 276                         ptr =  IVAL(blob->data, head_ofs); head_ofs += 4;
 277
 278                         b = (DATA_BLOB *)va_arg(ap, void *);
 279                         if (len1 == 0 && len2 == 0) {
 280                                 *b = data_blob(NULL, 0);
 281                         } else {
 282                                 /* make sure its in the right format - be strict */
 283                                 if ((len1 != len2) || (ptr + len1 < ptr) || (ptr + len1 < len1) || (ptr + len1 > blob->length)) {
 284                                         return False;
 285                                 }
 286                                 *b = data_blob(blob->data + ptr, len1);
 287                         }
 288                         break;
 289                 case 'b':
 290                         b = (DATA_BLOB *)va_arg(ap, void *);
 291                         len1 = va_arg(ap, unsigned);
 292                         /* make sure its in the right format - be strict */
 293                         NEED_DATA(len1);
 294                         *b = data_blob(blob->data + head_ofs, len1);
 295                         head_ofs += len1;
 296                         break;
 297                 case 'd':
 298                         v = va_arg(ap, uint32 *);
 299                         NEED_DATA(4);
 300                         *v = IVAL(blob->data, head_ofs); head_ofs += 4;
 301                         break;
 302                 case 'C':
 303                         s = va_arg(ap, char *);
 304                         head_ofs += pull_string(NULL, p, blob->data+head_ofs, sizeof(p),
 305                                                 blob->length - head_ofs,
 306                                                 STR_ASCII|STR_TERMINATE);
 307                         if (strcmp(s, p) != 0) {
 308                                 return False;
 309                         }
 310                         break;
 311                 }
 312         }
 313         va_end(ap);
 314
 315         return True;
 316 }