source/passdb/smbpass.c

   1 #ifdef SMB_PASSWD
   2 /*
   3  * Unix SMB/Netbios implementation. Version 1.9. SMB parameters and setup
   4  * Copyright (C) Andrew Tridgell 1992-1995 Modified by Jeremy Allison 1995.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it under
   7  * the terms of the GNU General Public License as published by the Free
   8  * Software Foundation; either version 2 of the License, or (at your option)
   9  * any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14  * more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along with
  17  * this program; if not, write to the Free Software Foundation, Inc., 675
  18  * Mass Ave, Cambridge, MA 02139, USA.
  19  */
  20
  21 #include "includes.h"
  22
  23 extern int      DEBUGLEVEL;
  24
  25 int             gotalarm;
  26
  27 void
  28 gotalarm_sig()
  29 {
  30         gotalarm = 1;
  31 }
  32
  33 int
  34 do_pw_lock(int fd, int waitsecs, int type)
  35 {
  36         struct flock    lock;
  37         int             ret;
  38
  39         gotalarm = 0;
  40         signal(SIGALRM, SIGNAL_CAST gotalarm_sig);
  41
  42         lock.l_type = type;
  43         lock.l_whence = SEEK_SET;
  44         lock.l_start = 0;
  45         lock.l_len = 1;
  46         lock.l_pid = 0;
  47
  48         alarm(5);
  49         ret = fcntl(fd, F_SETLKW, &lock);
  50         alarm(0);
  51         signal(SIGALRM, SIGNAL_CAST SIG_DFL);
  52
  53         if (gotalarm) {
  54                 DEBUG(0, ("do_pw_lock: failed to %s SMB passwd file.\n",
  55                           type == F_UNLCK ? "unlock" : "lock"));
  56                 return -1;
  57         }
  58         return ret;
  59 }
  60
  61 int pw_file_lock(char *name, int type, int secs)
  62 {
  63         int             fd = open(name, O_RDWR | O_CREAT, 0666);
  64         if (fd < 0)
  65                 return (-1);
  66         if (do_pw_lock(fd, secs, type)) {
  67                 close(fd);
  68                 return -1;
  69         }
  70         return fd;
  71 }
  72
  73 int pw_file_unlock(int fd)
  74 {
  75         do_pw_lock(fd, 5, F_UNLCK);
  76         return close(fd);
  77 }
  78
  79 /*
  80  * Routine to get the next 32 hex characters and turn them
  81  * into a 16 byte array.
  82  */
  83
  84 static int gethexpwd(char *p, char *pwd)
  85 {
  86         int i;
  87         unsigned char   lonybble, hinybble;
  88         char           *hexchars = "0123456789ABCDEF";
  89         char           *p1, *p2;
  90
  91         for (i = 0; i < 32; i += 2) {
  92                 hinybble = toupper(p[i]);
  93                 lonybble = toupper(p[i + 1]);
  94
  95                 p1 = strchr(hexchars, hinybble);
  96                 p2 = strchr(hexchars, lonybble);
  97                 if (!p1 || !p2)
  98                         return (False);
  99                 hinybble = PTR_DIFF(p1, hexchars);
 100                 lonybble = PTR_DIFF(p2, hexchars);
 101
 102                 pwd[i / 2] = (hinybble << 4) | lonybble;
 103         }
 104         return (True);
 105 }
 106
 107 /*
 108  * Routine to search the smbpasswd file for an entry matching the username.
 109  */
 110 struct smb_passwd *get_smbpwnam(char *name)
 111 {
 112         /* Static buffers we will return. */
 113         static struct smb_passwd pw_buf;
 114         static pstring  user_name;
 115         static unsigned char smbpwd[16];
 116         static unsigned char smbntpwd[16];
 117         char            linebuf[256];
 118         char            readbuf[16 * 1024];
 119         unsigned char   c;
 120         unsigned char  *p;
 121         long            uidval;
 122         long            linebuf_len;
 123         FILE           *fp;
 124         int             lockfd;
 125         char           *pfile = lp_smb_passwd_file();
 126
 127         if (!*pfile) {
 128                 DEBUG(0, ("No SMB password file set\n"));
 129                 return (NULL);
 130         }
 131         DEBUG(10, ("get_smbpwnam: opening file %s\n", pfile));
 132
 133         fp = fopen(pfile, "r");
 134
 135         if (fp == NULL) {
 136                 DEBUG(0, ("get_smbpwnam: unable to open file %s\n", pfile));
 137                 return NULL;
 138         }
 139         /* Set a 16k buffer to do more efficient reads */
 140         setvbuf(fp, readbuf, _IOFBF, sizeof(readbuf));
 141
 142         if ((lockfd = pw_file_lock(pfile, F_RDLCK, 5)) < 0) {
 143                 DEBUG(0, ("get_smbpwnam: unable to lock file %s\n", pfile));
 144                 fclose(fp);
 145                 return NULL;
 146         }
 147         /* make sure it is only rw by the owner */
 148         chmod(pfile, 0600);
 149
 150         /* We have a read lock on the file. */
 151         /*
 152          * Scan the file, a line at a time and check if the name matches.
 153          */
 154         while (!feof(fp)) {
 155                 linebuf[0] = '\0';
 156
 157                 fgets(linebuf, 256, fp);
 158                 if (ferror(fp)) {
 159                         fclose(fp);
 160                         pw_file_unlock(lockfd);
 161                         return NULL;
 162                 }
 163                 /*
 164                  * Check if the string is terminated with a newline - if not
 165                  * then we must keep reading and discard until we get one.
 166                  */
 167                 linebuf_len = strlen(linebuf);
 168                 if (linebuf[linebuf_len - 1] != '\n') {
 169                         c = '\0';
 170                         while (!ferror(fp) && !feof(fp)) {
 171                                 c = fgetc(fp);
 172                                 if (c == '\n')
 173                                         break;
 174                         }
 175                 } else
 176                         linebuf[linebuf_len - 1] = '\0';
 177
 178 #ifdef DEBUG_PASSWORD
 179                 DEBUG(100, ("get_smbpwnam: got line |%s|\n", linebuf));
 180 #endif
 181                 if ((linebuf[0] == 0) && feof(fp)) {
 182                         DEBUG(4, ("get_smbpwnam: end of file reached\n"));
 183                         break;
 184                 }
 185                 /*
 186                  * The line we have should be of the form :-
 187                  *
 188                  * username:uid:[32hex bytes]:....other flags presently
 189                  * ignored....
 190                  *
 191                  * or,
 192                  *
 193                  * username:uid:[32hex bytes]:[32hex bytes]:....ignored....
 194                  *
 195                  * if Windows NT compatible passwords are also present.
 196                  */
 197
 198                 if (linebuf[0] == '#' || linebuf[0] == '\0') {
 199                         DEBUG(6, ("get_smbpwnam: skipping comment or blank line\n"));
 200                         continue;
 201                 }
 202                 p = (unsigned char *) strchr(linebuf, ':');
 203                 if (p == NULL) {
 204                         DEBUG(0, ("get_smbpwnam: malformed password entry (no :)\n"));
 205                         continue;
 206                 }
 207                 /*
 208                  * As 256 is shorter than a pstring we don't need to check
 209                  * length here - if this ever changes....
 210                  */
 211                 strncpy(user_name, linebuf, PTR_DIFF(p, linebuf));
 212                 user_name[PTR_DIFF(p, linebuf)] = '\0';
 213                 if (!strequal(user_name, name))
 214                         continue;
 215
 216                 /* User name matches - get uid and password */
 217                 p++;            /* Go past ':' */
 218                 if (!isdigit(*p)) {
 219                         DEBUG(0, ("get_smbpwnam: malformed password entry (uid not number)\n"));
 220                         fclose(fp);
 221                         pw_file_unlock(lockfd);
 222                         return NULL;
 223                 }
 224                 uidval = atoi((char *) p);
 225                 while (*p && isdigit(*p))
 226                         p++;
 227                 if (*p != ':') {
 228                         DEBUG(0, ("get_smbpwnam: malformed password entry (no : after uid)\n"));
 229                         fclose(fp);
 230                         pw_file_unlock(lockfd);
 231                         return NULL;
 232                 }
 233                 /*
 234                  * Now get the password value - this should be 32 hex digits
 235                  * which are the ascii representations of a 16 byte string.
 236                  * Get two at a time and put them into the password.
 237                  */
 238                 p++;
 239                 if (*p == '*' || *p == 'X') {
 240                         /* Password deliberately invalid - end here. */
 241                         DEBUG(10, ("get_smbpwnam: entry invalidated for user %s\n", user_name));
 242                         fclose(fp);
 243                         pw_file_unlock(lockfd);
 244                         return NULL;
 245                 }
 246                 if (linebuf_len < (PTR_DIFF(p, linebuf) + 33)) {
 247                         DEBUG(0, ("get_smbpwnam: malformed password entry (passwd too short)\n"));
 248                         fclose(fp);
 249                         pw_file_unlock(lockfd);
 250                         return (False);
 251                 }
 252                 if (p[32] != ':') {
 253                         DEBUG(0, ("get_smbpwnam: malformed password entry (no terminating :)\n"));
 254                         fclose(fp);
 255                         pw_file_unlock(lockfd);
 256                         return NULL;
 257                 }
 258                 if (!strncasecmp((char *) p, "NO PASSWORD", 11)) {
 259                         pw_buf.smb_passwd = NULL;
 260                 } else {
 261                         if(!gethexpwd((char *)p,(char *)smbpwd)) {
 262                                 DEBUG(0, ("Malformed Lanman password entry (non hex chars)\n"));
 263                                 fclose(fp);
 264                                 pw_file_unlock(lockfd);
 265                                 return NULL;
 266                         }
 267                         pw_buf.smb_passwd = smbpwd;
 268                 }
 269                 pw_buf.smb_name = user_name;
 270                 pw_buf.smb_userid = uidval;
 271                 pw_buf.smb_nt_passwd = NULL;
 272
 273                 /* Now check if the NT compatible password is
 274                         available. */
 275                 p += 33; /* Move to the first character of the line after
 276                                         the lanman password. */
 277                 if ((linebuf_len >= (PTR_DIFF(p, linebuf) + 33)) && (p[32] == ':')) {
 278                         if (*p != '*' && *p != 'X') {
 279                                 if(gethexpwd((char *)p,(char *)smbntpwd))
 280                                         pw_buf.smb_nt_passwd = smbntpwd;
 281                         }
 282                 }
 283
 284                 fclose(fp);
 285                 pw_file_unlock(lockfd);
 286                 DEBUG(5, ("get_smbpwname: returning passwd entry for user %s, uid %d\n",
 287                           user_name, uidval));
 288                 return &pw_buf;
 289         }
 290
 291         fclose(fp);
 292         pw_file_unlock(lockfd);
 293         return NULL;
 294 }
 295 #else
 296  void smbpass_dummy(void)
 297 {
 298 }                               /* To avoid compiler complaints */
 299 #endif