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diff --git a/docs/htmldocs/pwencrypt.html b/docs/htmldocs/pwencrypt.html new file mode 100644 index 0000000000..9414399bf4 --- /dev/null +++ b/docs/htmldocs/pwencrypt.html @@ -0,0 +1,434 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> +<HTML +><HEAD +><TITLE +>LanMan and NT Password Encryption in Samba</TITLE +><META +NAME="GENERATOR" +CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ +"><LINK +REL="HOME" +TITLE="SAMBA Project Documentation" +HREF="samba-howto-collection.html"><LINK +REL="UP" +TITLE="General installation" +HREF="introduction.html"><LINK +REL="PREVIOUS" +TITLE="Quick Cross Subnet Browsing / Cross Workgroup Browsing guide" +HREF="browsing-quick.html"><LINK +REL="NEXT" +TITLE="Type of installation" +HREF="type.html"></HEAD +><BODY +CLASS="CHAPTER" +BGCOLOR="#FFFFFF" +TEXT="#000000" +LINK="#0000FF" +VLINK="#840084" +ALINK="#0000FF" +><DIV +CLASS="NAVHEADER" +><TABLE +SUMMARY="Header navigation table" +WIDTH="100%" +BORDER="0" +CELLPADDING="0" +CELLSPACING="0" +><TR +><TH +COLSPAN="3" +ALIGN="center" +>SAMBA Project Documentation</TH +></TR +><TR +><TD +WIDTH="10%" +ALIGN="left" +VALIGN="bottom" +><A +HREF="browsing-quick.html" +ACCESSKEY="P" +>Prev</A +></TD +><TD +WIDTH="80%" +ALIGN="center" +VALIGN="bottom" +></TD +><TD +WIDTH="10%" +ALIGN="right" +VALIGN="bottom" +><A +HREF="type.html" +ACCESSKEY="N" +>Next</A +></TD +></TR +></TABLE +><HR +ALIGN="LEFT" +WIDTH="100%"></DIV +><DIV +CLASS="CHAPTER" +><H1 +><A +NAME="PWENCRYPT">Chapter 4. LanMan and NT Password Encryption in Samba</H1 +><DIV +CLASS="SECT1" +><H1 +CLASS="SECT1" +><A +NAME="AEN457">4.1. Introduction</H1 +><P +>Newer windows clients send encrypted passwords over + the wire, instead of plain text passwords. The newest clients + will only send encrypted passwords and refuse to send plain text + passwords, unless their registry is tweaked.</P +><P +>These passwords can't be converted to unix style encrypted + passwords. Because of that you can't use the standard unix + user database, and you have to store the Lanman and NT hashes + somewhere else. For more information, see the documentation + about the <B +CLASS="COMMAND" +>passdb backend = </B +> parameter. + </P +></DIV +><DIV +CLASS="SECT1" +><H1 +CLASS="SECT1" +><A +NAME="AEN462">4.2. Important Notes About Security</H1 +><P +>The unix and SMB password encryption techniques seem similar + on the surface. This similarity is, however, only skin deep. The unix + scheme typically sends clear text passwords over the network when + logging in. This is bad. The SMB encryption scheme never sends the + cleartext password over the network but it does store the 16 byte + hashed values on disk. This is also bad. Why? Because the 16 byte hashed + values are a "password equivalent". You cannot derive the user's + password from them, but they could potentially be used in a modified + client to gain access to a server. This would require considerable + technical knowledge on behalf of the attacker but is perfectly possible. + You should thus treat the smbpasswd file as though it contained the + cleartext passwords of all your users. Its contents must be kept + secret, and the file should be protected accordingly.</P +><P +>Ideally we would like a password scheme which neither requires + plain text passwords on the net or on disk. Unfortunately this + is not available as Samba is stuck with being compatible with + other SMB systems (WinNT, WfWg, Win95 etc). </P +><DIV +CLASS="WARNING" +><P +></P +><TABLE +CLASS="WARNING" +WIDTH="100%" +BORDER="0" +><TR +><TD +WIDTH="25" +ALIGN="CENTER" +VALIGN="TOP" +><IMG +SRC="../images/warning.gif" +HSPACE="5" +ALT="Warning"></TD +><TD +ALIGN="LEFT" +VALIGN="TOP" +><P +>Note that Windows NT 4.0 Service pack 3 changed the + default for permissible authentication so that plaintext + passwords are <SPAN +CLASS="emphasis" +><I +CLASS="EMPHASIS" +>never</I +></SPAN +> sent over the wire. + The solution to this is either to switch to encrypted passwords + with Samba or edit the Windows NT registry to re-enable plaintext + passwords. See the document WinNT.txt for details on how to do + this.</P +><P +>Other Microsoft operating systems which also exhibit + this behavior includes</P +><P +></P +><UL +><LI +><P +>MS DOS Network client 3.0 with + the basic network redirector installed</P +></LI +><LI +><P +>Windows 95 with the network redirector + update installed</P +></LI +><LI +><P +>Windows 98 [se]</P +></LI +><LI +><P +>Windows 2000</P +></LI +></UL +><P +><SPAN +CLASS="emphasis" +><I +CLASS="EMPHASIS" +>Note :</I +></SPAN +>All current release of + Microsoft SMB/CIFS clients support authentication via the + SMB Challenge/Response mechanism described here. Enabling + clear text authentication does not disable the ability + of the client to participate in encrypted authentication.</P +></TD +></TR +></TABLE +></DIV +><DIV +CLASS="SECT2" +><H2 +CLASS="SECT2" +><A +NAME="AEN481">4.2.1. Advantages of SMB Encryption</H2 +><P +></P +><UL +><LI +><P +>plain text passwords are not passed across + the network. Someone using a network sniffer cannot just + record passwords going to the SMB server.</P +></LI +><LI +><P +>WinNT doesn't like talking to a server + that isn't using SMB encrypted passwords. It will refuse + to browse the server if the server is also in user level + security mode. It will insist on prompting the user for the + password on each connection, which is very annoying. The + only things you can do to stop this is to use SMB encryption. + </P +></LI +></UL +></DIV +><DIV +CLASS="SECT2" +><H2 +CLASS="SECT2" +><A +NAME="AEN488">4.2.2. Advantages of non-encrypted passwords</H2 +><P +></P +><UL +><LI +><P +>plain text passwords are not kept + on disk. </P +></LI +><LI +><P +>uses same password file as other unix + services such as login and ftp</P +></LI +><LI +><P +>you are probably already using other + services (such as telnet and ftp) which send plain text + passwords over the net, so sending them for SMB isn't + such a big deal.</P +></LI +></UL +></DIV +></DIV +><DIV +CLASS="SECT1" +><H1 +CLASS="SECT1" +><A +NAME="AEN497">4.3. The smbpasswd Command</H1 +><P +>The smbpasswd command maintains the two 32 byte password fields + in the smbpasswd file. If you wish to make it similar to the unix + <B +CLASS="COMMAND" +>passwd</B +> or <B +CLASS="COMMAND" +>yppasswd</B +> programs, + install it in <TT +CLASS="FILENAME" +>/usr/local/samba/bin/</TT +> (or your + main Samba binary directory).</P +><P +><B +CLASS="COMMAND" +>smbpasswd</B +> now works in a client-server mode + where it contacts the local smbd to change the user's password on its + behalf. This has enormous benefits - as follows.</P +><P +><B +CLASS="COMMAND" +>smbpasswd</B +> now has the capability + to change passwords on Windows NT servers (this only works when + the request is sent to the NT Primary Domain Controller if you + are changing an NT Domain user's password).</P +><P +>To run smbpasswd as a normal user just type :</P +><P +><TT +CLASS="PROMPT" +>$ </TT +><TT +CLASS="USERINPUT" +><B +>smbpasswd</B +></TT +></P +><P +><TT +CLASS="PROMPT" +>Old SMB password: </TT +><TT +CLASS="USERINPUT" +><B +><type old value here - + or hit return if there was no old password></B +></TT +></P +><P +><TT +CLASS="PROMPT" +>New SMB Password: </TT +><TT +CLASS="USERINPUT" +><B +><type new value> + </B +></TT +></P +><P +><TT +CLASS="PROMPT" +>Repeat New SMB Password: </TT +><TT +CLASS="USERINPUT" +><B +><re-type new value + </B +></TT +></P +><P +>If the old value does not match the current value stored for + that user, or the two new values do not match each other, then the + password will not be changed.</P +><P +>If invoked by an ordinary user it will only allow the user + to change his or her own Samba password.</P +><P +>If run by the root user smbpasswd may take an optional + argument, specifying the user name whose SMB password you wish to + change. Note that when run as root smbpasswd does not prompt for + or check the old password value, thus allowing root to set passwords + for users who have forgotten their passwords.</P +><P +><B +CLASS="COMMAND" +>smbpasswd</B +> is designed to work in the same way + and be familiar to UNIX users who use the <B +CLASS="COMMAND" +>passwd</B +> or + <B +CLASS="COMMAND" +>yppasswd</B +> commands.</P +><P +>For more details on using <B +CLASS="COMMAND" +>smbpasswd</B +> refer + to the man page which will always be the definitive reference.</P +></DIV +></DIV +><DIV +CLASS="NAVFOOTER" +><HR +ALIGN="LEFT" +WIDTH="100%"><TABLE +SUMMARY="Footer navigation table" +WIDTH="100%" +BORDER="0" +CELLPADDING="0" +CELLSPACING="0" +><TR +><TD +WIDTH="33%" +ALIGN="left" +VALIGN="top" +><A +HREF="browsing-quick.html" +ACCESSKEY="P" +>Prev</A +></TD +><TD +WIDTH="34%" +ALIGN="center" +VALIGN="top" +><A +HREF="samba-howto-collection.html" +ACCESSKEY="H" +>Home</A +></TD +><TD +WIDTH="33%" +ALIGN="right" +VALIGN="top" +><A +HREF="type.html" +ACCESSKEY="N" +>Next</A +></TD +></TR +><TR +><TD +WIDTH="33%" +ALIGN="left" +VALIGN="top" +>Quick Cross Subnet Browsing / Cross Workgroup Browsing guide</TD +><TD +WIDTH="34%" +ALIGN="center" +VALIGN="top" +><A +HREF="introduction.html" +ACCESSKEY="U" +>Up</A +></TD +><TD +WIDTH="33%" +ALIGN="right" +VALIGN="top" +>Type of installation</TD +></TR +></TABLE +></DIV +></BODY +></HTML +>
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