docs/htmldocs/smbpasswd.5.html

   1 <HTML
   2 ><HEAD
   3 ><TITLE
   4 >smbpasswd</TITLE
   5 ><META
   6 NAME="GENERATOR"
   7 CONTENT="Modular DocBook HTML Stylesheet Version 1.57"></HEAD
   8 ><BODY
   9 CLASS="REFENTRY"
  10 BGCOLOR="#FFFFFF"
  11 TEXT="#000000"
  12 LINK="#0000FF"
  13 VLINK="#840084"
  14 ALINK="#0000FF"
  15 ><H1
  16 ><A
  17 NAME="SMBPASSWD"
  18 >smbpasswd</A
  19 ></H1
  20 ><DIV
  21 CLASS="REFNAMEDIV"
  22 ><A
  23 NAME="AEN5"
  24 ></A
  25 ><H2
  26 >Name</H2
  27 >smbpasswd&nbsp;--&nbsp;The Samba encrypted password file</DIV
  28 ><DIV
  29 CLASS="REFSYNOPSISDIV"
  30 ><A
  31 NAME="AEN8"
  32 ></A
  33 ><H2
  34 >Synopsis</H2
  35 ><P
  36 ><TT
  37 CLASS="FILENAME"
  38 >smbpasswd</TT
  39 ></P
  40 ></DIV
  41 ><DIV
  42 CLASS="REFSECT1"
  43 ><A
  44 NAME="AEN11"
  45 ></A
  46 ><H2
  47 >DESCRIPTION</H2
  48 ><P
  49 >This tool is part of the <A
  50 HREF="samba.7.html"
  51 TARGET="_top"
  52 >       Samba</A
  53 > suite.</P
  54 ><P
  55 >smbpasswd is the Samba encrypted password file. It contains
  56         the username, Unix user id and the SMB hashed passwords of the
  57         user, as well as account flag information and the time the
  58         password was last changed. This file format has been evolving with
  59         Samba and has had several different formats in the past. </P
  60 ></DIV
  61 ><DIV
  62 CLASS="REFSECT1"
  63 ><A
  64 NAME="AEN16"
  65 ></A
  66 ><H2
  67 >FILE FORMAT</H2
  68 ><P
  69 >The format of the smbpasswd file used by Samba 2.2
  70         is very similar to the familiar Unix <TT
  71 CLASS="FILENAME"
  72 >passwd(5)</TT
  73 >
  74         file. It is an ASCII file containing one line for each user. Each field
  75         ithin each line is separated from the next by a colon. Any entry
  76         beginning with '#' is ignored. The smbpasswd file contains the
  77         following information for each user: </P
  78 ><P
  79 ></P
  80 ><DIV
  81 CLASS="VARIABLELIST"
  82 ><DL
  83 ><DT
  84 >name</DT
  85 ><DD
  86 ><P
  87 > This is the user name. It must be a name that
  88                 already exists in the standard UNIX passwd file. </P
  89 ></DD
  90 ><DT
  91 >uid</DT
  92 ><DD
  93 ><P
  94 >This is the UNIX uid. It must match the uid
  95                 field for the same user entry in the standard UNIX passwd file.
  96                 If this does not match then Samba will refuse to recognize
  97                 this smbpasswd file entry as being valid for a user.
  98                 </P
  99 ></DD
 100 ><DT
 101 >Lanman Password Hash</DT
 102 ><DD
 103 ><P
 104 >This is the LANMAN hash of the users password,
 105                 encoded as 32 hex digits.  The LANMAN hash is created by DES
 106                 encrypting a well known string with the users password as the
 107                 DES key. This is the same password used by Windows 95/98 machines.
 108                 Note that this password hash is regarded as weak as it is
 109                 vulnerable to dictionary attacks and if two users choose the
 110                 same password this entry will be identical (i.e. the password
 111                 is not "salted" as the UNIX password is). If the user has a
 112                 null password this field will contain the characters "NO PASSWORD"
 113                 as the start of the hex string. If the hex string is equal to
 114                 32 'X' characters then the users account is marked as
 115                 <TT
 116 CLASS="CONSTANT"
 117 >disabled</TT
 118 > and the user will not be able to
 119                 log onto the Samba server. </P
 120 ><P
 121 ><EM
 122 >WARNING !!</EM
 123 > Note that, due to
 124                 the challenge-response nature of the SMB/CIFS authentication
 125                 protocol, anyone with a knowledge of this password hash will
 126                 be able to impersonate the user on the network. For this
 127                 reason these hashes are known as <EM
 128 >plain text
 129                 equivalents</EM
 130 > and must <EM
 131 >NOT</EM
 132 > be made
 133                 available to anyone but the root user. To protect these passwords
 134                 the smbpasswd file is placed in a directory with read and
 135                 traverse access only to the root user and the smbpasswd file
 136                 itself must be set to be read/write only by root, with no
 137                 other access. </P
 138 ></DD
 139 ><DT
 140 >NT Password Hash</DT
 141 ><DD
 142 ><P
 143 >This is the Windows NT hash of the users
 144                 password, encoded as 32 hex digits.  The Windows NT hash is
 145                 created by taking the users password as represented in
 146                 16-bit, little-endian UNICODE and then applying the MD4
 147                 (internet rfc1321) hashing algorithm to it. </P
 148 ><P
 149 >This password hash is considered more secure than
 150                 the Lanman Password Hash as it preserves the case of the
 151                 password and uses a much higher quality hashing algorithm.
 152                 However, it is still the case that if two users choose the same
 153                 password this entry will be identical (i.e. the password is
 154                 not "salted" as the UNIX password is). </P
 155 ><P
 156 ><EM
 157 >WARNING !!</EM
 158 >. Note that, due to
 159                 the challenge-response nature of the SMB/CIFS authentication
 160                 protocol, anyone with a knowledge of this password hash will
 161                 be able to impersonate the user on the network. For this
 162                 reason these hashes are known as <EM
 163 >plain text
 164                 equivalents</EM
 165 > and must <EM
 166 >NOT</EM
 167 > be made
 168                 available to anyone but the root user. To protect these passwords
 169                 the smbpasswd file is placed in a directory with read and
 170                 traverse access only to the root user and the smbpasswd file
 171                 itself must be set to be read/write only by root, with no
 172                 other access. </P
 173 ></DD
 174 ><DT
 175 >Account Flags</DT
 176 ><DD
 177 ><P
 178 >This section contains flags that describe
 179                 the attributes of the users account. In the Samba 2.2 release
 180                 this field is bracketed by '[' and ']' characters and is always
 181                 13 characters in length (including the '[' and ']' characters).
 182                 The contents of this field may be any of the characters.
 183                 </P
 184 ><P
 185 ></P
 186 ><UL
 187 ><LI
 188 ><P
 189 ><EM
 190 >U</EM
 191 > - This means
 192                         this is a "User" account, i.e. an ordinary user. Only User
 193                         and Workstation Trust accounts are currently supported
 194                         in the smbpasswd file. </P
 195 ></LI
 196 ><LI
 197 ><P
 198 ><EM
 199 >N</EM
 200 > - This means the
 201                         account has no password (the passwords in the fields Lanman
 202                         Password Hash and NT Password Hash are ignored). Note that this
 203                         will only allow users to log on with no password if the <TT
 204 CLASS="PARAMETER"
 205 ><I
 206 >                       null passwords</I
 207 ></TT
 208 > parameter is set in the <A
 209 HREF="smb.conf.5.html#NULLPASSWORDS"
 210 TARGET="_top"
 211 ><TT
 212 CLASS="FILENAME"
 213 >smb.conf(5)
 214                         </TT
 215 ></A
 216 > config file. </P
 217 ></LI
 218 ><LI
 219 ><P
 220 ><EM
 221 >D</EM
 222 > - This means the account
 223                         is disabled and no SMB/CIFS logins  will be     allowed for
 224                         this user. </P
 225 ></LI
 226 ><LI
 227 ><P
 228 ><EM
 229 >W</EM
 230 > - This means this account
 231                         is a "Workstation Trust" account. This kind of account is used
 232                         in the Samba PDC code stream to allow Windows NT Workstations
 233                         and Servers to join a Domain hosted by a Samba PDC. </P
 234 ></LI
 235 ></UL
 236 ><P
 237 >Other flags may be added as the code is extended in future.
 238                 The rest of this field space is filled in with spaces. </P
 239 ></DD
 240 ><DT
 241 >Last Change Time</DT
 242 ><DD
 243 ><P
 244 >This field consists of the time the account was
 245                 last modified. It consists of the characters 'LCT-' (standing for
 246                 "Last Change Time") followed by a numeric encoding of the UNIX time
 247                 in seconds since the epoch (1970) that the last change was made.
 248                 </P
 249 ></DD
 250 ></DL
 251 ></DIV
 252 ><P
 253 >All other colon separated fields are ignored at this time.</P
 254 ></DIV
 255 ><DIV
 256 CLASS="REFSECT1"
 257 ><A
 258 NAME="AEN73"
 259 ></A
 260 ><H2
 261 >VERSION</H2
 262 ><P
 263 >This man page is correct for version 2.2 of
 264         the Samba suite.</P
 265 ></DIV
 266 ><DIV
 267 CLASS="REFSECT1"
 268 ><A
 269 NAME="AEN76"
 270 ></A
 271 ><H2
 272 >SEE ALSO</H2
 273 ><P
 274 ><A
 275 HREF="smbpasswd.8.html"
 276 TARGET="_top"
 277 ><B
 278 CLASS="COMMAND"
 279 >smbpasswd(8)</B
 280 ></A
 281 >,
 282         <A
 283 HREF="samba.7.html"
 284 TARGET="_top"
 285 >samba(7)</A
 286 >, and
 287         the Internet RFC1321 for details on the MD4 algorithm.
 288         </P
 289 ></DIV
 290 ><DIV
 291 CLASS="REFSECT1"
 292 ><A
 293 NAME="AEN82"
 294 ></A
 295 ><H2
 296 >AUTHOR</H2
 297 ><P
 298 >The original Samba software and related utilities
 299         were created by Andrew Tridgell. Samba is now developed
 300         by the Samba Team as an Open Source project similar
 301         to the way the Linux kernel is developed.</P
 302 ><P
 303 >The original Samba man pages were written by Karl Auer.
 304         The man page sources were converted to YODL format (another
 305         excellent piece of Open Source software, available at
 306         <A
 307 HREF="ftp://ftp.icce.rug.nl/pub/unix/"
 308 TARGET="_top"
 309 >       ftp://ftp.icce.rug.nl/pub/unix/</A
 310 >) and updated for the Samba 2.0
 311         release by Jeremy Allison.  The conversion to DocBook for
 312         Samba 2.2 was done by Gerald Carter</P
 313 ></DIV
 314 ></BODY
 315 ></HTML
 316 >