=== modified file 'Makefile' --- Makefile 2011-07-27 17:58:27 +0000 +++ Makefile 2011-08-08 21:12:37 +0000 @@ -92,7 +92,7 @@ plugins.d/mandos-client.8mandos \ plugins.d/password-prompt.8mandos plugins.d/usplash.8mandos \ plugins.d/splashy.8mandos plugins.d/askpass-fifo.8mandos \ - plugins.d/plymouth.8mandos + plugins.d/plymouth.8mandos intro.8mandos htmldocs=$(addsuffix .xhtml,$(DOCS)) @@ -119,6 +119,11 @@ %.8mandos.xhtml: %.xml common.ent legalnotice.xml $(DOCBOOKTOHTML) +intro.8mandos: intro.xml common.ent legalnotice.xml + $(DOCBOOKTOMAN) +intro.8mandos.xhtml: intro.xml common.ent legalnotice.xml + $(DOCBOOKTOHTML) + mandos.8: mandos.xml common.ent mandos-options.xml overview.xml \ legalnotice.xml $(DOCBOOKTOMAN) === modified file 'README' --- README 2011-08-07 14:49:02 +0000 +++ README 2011-08-08 21:12:37 +0000 @@ -1,185 +1,10 @@ --*- org -*- - -* Mandos - - Have your cake and eat it too! - - You know how it is. You’ve heard of it happening. The Man comes - and takes away your servers, your friends’ servers, the servers of - everybody in the same hosting facility. The servers of their - neighbors, and their neighbors’ friends. The servers of people who - owe them money. And like *that*, they’re gone. And you doubt - you’ll ever see them again. - - That is why your servers have encrypted root file systems. However, - there’s a downside. There’s no going around it: rebooting is a - pain. Dragging out that rarely-used keyboard and screen and - unraveling cables behind your servers to plug them in to type in - that password is messy, especially if you have many servers. There - are some people who do clever things like using serial line consoles - and daisy-chain it to the next server, and keep all the servers - connected in a ring with serial cables, which will work, if your - servers are physically close enough. There are also other - out-of-band management solutions, but with *all* these, you still - have to be on hand and manually type in the password at boot time. - Otherwise the server just sits there, waiting for a password. - - Wouldn’t it be great if you could have the security of encrypted - root file systems and still have servers that could boot up - automatically if there was a short power outage while you were - asleep? That you could reboot at will, without having someone run - over to the server to type in the password? - - Well, with Mandos, you (almost) can! The gain in convenience will - only be offset by a small loss in security. The setup is as - follows: - - The server will still have its encrypted root file system. The - password to this file system will be stored on another computer - (henceforth known as the Mandos server) on the same local network. - The password will *not* be stored in plaintext, but encrypted with - OpenPGP. To decrypt this password, a key is needed. This key (the - Mandos client key) will not be stored there, but back on the - original server (henceforth known as the Mandos client) in the - initial RAM disk image. Oh, and all network Mandos client/server - communications will be encrypted, using TLS (SSL). - - So, at boot time, the Mandos client will ask for its encrypted data - over the network, decrypt it to get the password, use it to decrypt - the root file, and continue booting. - - Now, of course the initial RAM disk image is not on the encrypted - root file system, so anyone who had physical access could take the - Mandos client computer offline and read the disk with their own - tools to get the authentication keys used by a client. *But*, by - then the Mandos server should notice that the original server has - been offline for too long, and will no longer give out the encrypted - key. The timing here is the only real weak point, and the method, - frequency and timeout of the server’s checking can be adjusted to - any desired level of paranoia - - (The encrypted keys on the Mandos server is on its normal file - system, so those are safe, provided the root file system of *that* - server is encrypted.) - -* FAQ - couldn’t the security be defeated by... - -** Grabbing the Mandos client key from the initrd *really quickly*? - This, as mentioned above, is the only real weak point. But if you - set the timing values tight enough, this will be really difficult - to do. An attacker would have to physically disassemble the client - computer, extract the key from the initial RAM disk image, and then - connect to a *still online* Mandos server to get the encrypted key, - and do all this *before* the Mandos server timeout kicks in and the - Mandos server refuses to give out the key to anyone. - - Now, as the typical procedure seems to be to barge in and turn off - and grab *all* computers, to maybe look at them months later, this - is not likely. If someone does that, the whole system *will* lock - itself up completely, since Mandos servers are no longer running. - - For sophisticated attackers who *could* do the clever thing, *and* - had physical access to the server for enough time, it would be - simpler to get a key for an encrypted file system by using hardware - memory scanners and reading it right off the memory bus. - -** Replay attacks? - Nope, the network stuff is all done over TLS, which provides - protection against that. - -** Man-in-the-middle? - No. The server only gives out the passwords to clients which have - *in the TLS handshake* proven that they do indeed hold the OpenPGP - private key corresponding to that client. - -** Physically grabbing the Mandos server computer? - You could protect *that* computer the old-fashioned way, with a - must-type-in-the-password-at-boot method. Or you could have two - computers be the Mandos server for each other. - - Multiple Mandos servers can coexist on a network without any - trouble. They do not clash, and clients will try all available - servers. This means that if just one reboots then the other can - bring it back up, but if both reboot at the same time they will - stay down until someone types in the password on one of them. - -** Faking ping replies? - The default for the server is to use "fping", the replies to which - could be faked to eliminate the timeout. But this could easily be - changed to any shell command, with any security measures you like. - It could, for instance, be changed to an SSH command with strict - keychecking, which could not be faked. Or IPsec could be used for - the ping packets, making them secure. - -* Security Summary - So, in summary: The only weakness in the Mandos system is from - people who have: - 1. The power to come in and physically take your servers, *and* - 2. The cunning and patience to do it carefully, one at a time, and - *quickly*, faking Mandos client/server responses for each one - before the timeout. - - While there are some who may be threatened by people who have *both* - these attributes, they do not, probably, constitute the majority. - - If you *do* face such opponents, you must figure that they could - just as well open your servers and read the file system keys right - off the memory by running wires to the memory bus. - - What Mandos is designed to protect against is *not* such determined, - focused, and competent attacks, but against the early morning knock - on your door and the sudden absence of all the servers in your - server room. Which it does nicely. - -* The Plugin System - In the early designs, the mandos-client(8mandos) program (which - retrieves a password from the Mandos server) also prompted for a - password on the terminal, in case a Mandos server could not be - found. Other ways of retrieving a password could easily be - envisoned, but this multiplicity of purpose was seen to be too - complex to be a viable way to continue. Instead, the original - program was separated into mandos-client(8mandos) and - password-prompt(8mandos), and a plugin-runner(8mandos) exist to run - them both in parallel, allowing the first successful plugin to - provide the password. This opened up for any number of additional - plugins to run, all competing to be the first to find a password and - provide it to the plugin runner. - - Four additional plugins are provided: - * plymouth(8mandos) - This prompts for a password when using plymouth(8). - * usplash(8mandos) - This prompts for a password when using usplash(8). - * splashy(8mandos) - This prompts for a password when using splashy(8). - * askpass-fifo(8mandos) - To provide compatibility with the "askpass" program from - cryptsetup, this plugin listens to the same FIFO as askpass would - do. - - More plugins can easily be written and added by the system - administrator; see the section called "WRITING PLUGINS" in - plugin-runner(8mandos) to learn the plugin requirements. - -* Copyright - - Copyright © 2008-2011 Teddy Hogeborn - Copyright © 2008-2011 Björn Påhlsson - -** License: - - This program is free software: you can redistribute it and/or - modify it under the terms of the GNU General Public License as - published by the Free Software Foundation, either version 3 of the - License, or (at your option) any later version. - - This program is distributed in the hope that it will be useful, but - WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program. If not, see - . - - -#+STARTUP: showall +Please see: http://www.fukt.bsnet.se/mandos/man/intro.8mandos + +This information previously in this file has been moved to the +intro(8mandos) manual page. Go to the above URL, or run this command: + + make intro.8mandos && man -l intro.8mandos + +In short, this is the Mandos system; it allows computers to have +encrypted root file systems and at the same time be capable of remote +and/or unattended reboots. === modified file 'TODO' --- TODO 2011-07-31 13:05:34 +0000 +++ TODO 2011-08-08 21:12:37 +0000 @@ -4,8 +4,6 @@ * mandos-applet -* Convert README into intro(8mandos) man page - * mandos-client ** TODO [#B] Use capabilities instead of seteuid(). ** TODO [#B] Use struct sockaddr_storage instead of a union === added file 'intro.xml' --- intro.xml 1970-01-01 00:00:00 +0000 +++ intro.xml 2011-08-08 21:12:37 +0000 @@ -0,0 +1,410 @@ + + + +%common; +]> + + + + Mandos Manual + + Mandos + &version; + &TIMESTAMP; + + + Björn + Påhlsson +
+ belorn@fukt.bsnet.se +
+ + + Teddy + Hogeborn +
+ teddy@fukt.bsnet.se +
+ + + + 2011 + Teddy Hogeborn + Björn Påhlsson + + + + + + intro + 8mandos + + + + intro + + Introduction to the Mandos system + + + + + DESCRIPTION + + This is the the Mandos system, which allows computers to have + encrypted root file systems and at the same time be capable of + remote and/or unattended reboots. + + + The computers run a small client program in the initial RAM disk + environment which will communicate with a server over a network. + All network communication is encrypted using TLS. The clients + are identified by the server using an OpenPGP key; each client + has one unique to it. The server sends the clients an encrypted + password. The encrypted password is decrypted by the clients + using the same OpenPGP key, and the password is then used to + unlock the root file system, whereupon the computers can + continue booting normally. + + + + + INTRODUCTION + + You know how it is. You’ve heard of it happening. The Man + comes and takes away your servers, your friends’ servers, the + servers of everybody in the same hosting facility. The servers + of their neighbors, and their neighbors’ friends. The servers + of people who owe them money. And like + that, they’re gone. And you doubt you’ll + ever see them again. + + + That is why your servers have encrypted root file systems. + However, there’s a downside. There’s no going around it: + rebooting is a pain. Dragging out that rarely-used keyboard and + screen and unraveling cables behind your servers to plug them in + to type in that password is messy, especially if you have many + servers. There are some people who do clever things like using + serial line consoles and daisy-chain it to the next server, and + keep all the servers connected in a ring with serial cables, + which will work, if your servers are physically close enough. + There are also other out-of-band management solutions, but with + all these, you still have to be on hand and + manually type in the password at boot time. Otherwise the + server just sits there, waiting for a password. + + + Wouldn’t it be great if you could have the security of encrypted + root file systems and still have servers that could boot up + automatically if there was a short power outage while you were + asleep? That you could reboot at will, without having someone + run over to the server to type in the password? + + + Well, with Mandos, you (almost) can! The gain in convenience + will only be offset by a small loss in security. The setup is + as follows: + + + The server will still have its encrypted root file system. The + password to this file system will be stored on another computer + (henceforth known as the Mandos server) on the same local + network. The password will not be stored + in plaintext, but encrypted with OpenPGP. To decrypt this + password, a key is needed. This key (the Mandos client key) + will not be stored there, but back on the original server + (henceforth known as the Mandos client) in the initial RAM disk + image. Oh, and all network Mandos client/server communications + will be encrypted, using TLS (SSL). + + + So, at boot time, the Mandos client will ask for its encrypted + data over the network, decrypt it to get the password, use it to + decrypt the root file, and continue booting. + + + Now, of course the initial RAM disk image is not on the + encrypted root file system, so anyone who had physical access + could take the Mandos client computer offline and read the disk + with their own tools to get the authentication keys used by a + client. But, by then the Mandos server + should notice that the original server has been offline for too + long, and will no longer give out the encrypted key. The timing + here is the only real weak point, and the method, frequency and + timeout of the server’s checking can be adjusted to any desired + level of paranoia + + + (The encrypted keys on the Mandos server is on its normal file + system, so those are safe, provided the root file system of + that server is encrypted.) + + + + + FREQUENTLY ASKED QUESTIONS + + Couldn’t the security be defeated by… + + + Grabbing the Mandos client key from the + initrd <emphasis>really quickly</emphasis>? + + This, as mentioned above, is the only real weak point. But if + you set the timing values tight enough, this will be really + difficult to do. An attacker would have to physically + disassemble the client computer, extract the key from the + initial RAM disk image, and then connect to a still + online Mandos server to get the encrypted key, and do + all this before the Mandos server timeout + kicks in and the Mandos server refuses to give out the key to + anyone. + + + Now, as the typical procedure seems to be to barge in and turn + off and grab all computers, to maybe look + at them months later, this is not likely. If someone does that, + the whole system will lock itself up + completely, since Mandos servers are no longer running. + + + For sophisticated attackers who could do + the clever thing, and had physical access + to the server for enough time, it would be simpler to get a key + for an encrypted file system by using hardware memory scanners + and reading it right off the memory bus. + + + + + Replay attacks? + + Nope, the network stuff is all done over TLS, which provides + protection against that. + + + + + Man-in-the-middle? + + No. The server only gives out the passwords to clients which + have in the TLS handshake proven that + they do indeed hold the OpenPGP private key corresponding to + that client. + + + + + Physically grabbing the Mandos server computer? + + You could protect that computer the + old-fashioned way, with a must-type-in-the-password-at-boot + method. Or you could have two computers be the Mandos server + for each other. + + + Multiple Mandos servers can coexist on a network without any + trouble. They do not clash, and clients will try all + available servers. This means that if just one reboots then + the other can bring it back up, but if both reboot at the same + time they will stay down until someone types in the password + on one of them. + + + + + Faking ping replies? + + The default for the server is to use + fping, the replies to which + could be faked to eliminate the timeout. But this could + easily be changed to any shell command, with any security + measures you like. It could, for instance, be changed to an + SSH command with strict keychecking, which could not be faked. + Or IPsec could be used for the ping packets, making them + secure. + + + + + + SECURITY + + So, in summary: The only weakness in the Mandos system is from + people who have: + + + + + The power to come in and physically take your servers, + and + + + + + The cunning and patience to do it carefully, one at a time, + and quickly, faking Mandos + client/server responses for each one before the timeout. + + + + + While there are some who may be threatened by people who have + both these attributes, they do not, + probably, constitute the majority. + + + If you do face such opponents, you must + figure that they could just as well open your servers and read + the file system keys right off the memory by running wires to + the memory bus. + + + What Mandos is designed to protect against is + not such determined, focused, and competent + attacks, but against the early morning knock on your door and + the sudden absence of all the servers in your server room. + Which it does nicely. + + + + + PLUGINS + + In the early designs, the + mandos-client8mandos program (which + retrieves a password from the Mandos server) also prompted for a + password on the terminal, in case a Mandos server could not be + found. Other ways of retrieving a password could easily be + envisoned, but this multiplicity of purpose was seen to be too + complex to be a viable way to continue. Instead, the original + program was separated into mandos-client8mandos and password-prompt8mandos, and a plugin-runner8mandos exist to run them both in parallel, allowing + the first successful plugin to provide the password. This + opened up for any number of additional plugins to run, all + competing to be the first to find a password and provide it to + the plugin runner. + + + Four additional plugins are provided: + + + + + plymouth + 8mandos + + + + This prompts for a password when using + plymouth8. + + + + + + usplash + 8mandos + + + + This prompts for a password when using + usplash8. + + + + + + splashy + 8mandos + + + + This prompts for a password when using + splashy8. + + + + + + askpass-fifo + 8mandos + + + + To provide compatibility with the "askpass" program from + cryptsetup, this plugin listens to the same FIFO as + askpass would do. + + + + + + More plugins can easily be written and added by the system + administrator; see the section called "WRITING PLUGINS" in + plugin-runner + 8mandos to learn the + plugin requirements. + + + + + SEE ALSO + + mandos + 8, + mandos.conf + 5, + mandos-clients.conf + 5, + mandos-ctl + 8, + mandos-monitor + 8, + plugin-runner + 8mandos, + mandos-client + 8mandos, + password-prompt + 8mandos, + plymouth + 8mandos, + usplash + 8mandos, + splashy + 8mandos, + askpass-fifo + 8mandos, + mandos-keygen + 8 + + + + + Mandos + + + + The Mandos home page. + + + + + + + + + + + === modified file 'mandos-clients.conf.xml' --- mandos-clients.conf.xml 2011-02-27 17:26:35 +0000 +++ mandos-clients.conf.xml 2011-08-08 21:12:37 +0000 @@ -3,7 +3,7 @@ "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [ /etc/mandos/clients.conf"> - + %common; ]> @@ -460,6 +460,8 @@ SEE ALSO + intro + 8mandos, mandos-keygen 8, mandos.conf === modified file 'mandos-ctl.xml' --- mandos-ctl.xml 2011-02-27 17:26:35 +0000 +++ mandos-ctl.xml 2011-08-08 21:12:37 +0000 @@ -2,7 +2,7 @@ - + %common; ]> @@ -554,6 +554,8 @@ SEE ALSO + intro + 8mandos, mandos 8, mandos-clients.conf === modified file 'mandos-keygen.xml' --- mandos-keygen.xml 2009-01-04 21:54:55 +0000 +++ mandos-keygen.xml 2011-08-08 21:12:37 +0000 @@ -2,7 +2,7 @@ - + %common; ]> @@ -33,6 +33,7 @@ 2008 2009 + 2011 Teddy Hogeborn Björn Påhlsson @@ -492,6 +493,8 @@ SEE ALSO + intro + 8mandos, gpg 1, mandos-clients.conf === modified file 'mandos-monitor.xml' --- mandos-monitor.xml 2011-02-27 17:26:35 +0000 +++ mandos-monitor.xml 2011-08-08 21:12:37 +0000 @@ -2,7 +2,7 @@ - + %common; ]> @@ -219,6 +219,8 @@ SEE ALSO + intro + 8mandos, mandos 8, mandos-ctl === modified file 'mandos.conf.xml' --- mandos.conf.xml 2009-02-25 01:14:29 +0000 +++ mandos.conf.xml 2011-08-08 21:12:37 +0000 @@ -3,7 +3,7 @@ "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [ /etc/mandos/mandos.conf"> - + %common; ]> @@ -34,6 +34,7 @@ 2008 2009 + 2011 Teddy Hogeborn Björn Påhlsson @@ -204,6 +205,8 @@ SEE ALSO + intro + 8mandos, gnutls_priority_init3, mandos === modified file 'mandos.xml' --- mandos.xml 2011-02-27 17:26:35 +0000 +++ mandos.xml 2011-08-08 21:12:37 +0000 @@ -2,7 +2,7 @@ - + %common; ]> @@ -610,15 +610,16 @@ SEE ALSO - - mandos-clients.conf - 5, - mandos.conf - 5, - mandos-client - 8mandos, - sh1 - + intro + 8mandos, + mandos-clients.conf + 5, + mandos.conf + 5, + mandos-client + 8mandos, + sh + 1 === modified file 'plugin-runner.xml' --- plugin-runner.xml 2009-01-18 06:41:57 +0000 +++ plugin-runner.xml 2011-08-08 21:12:37 +0000 @@ -2,7 +2,7 @@ - + %common; ]> @@ -33,6 +33,7 @@ 2008 2009 + 2011 Teddy Hogeborn Björn Påhlsson @@ -617,6 +618,8 @@ SEE ALSO + intro + 8mandos, cryptsetup 8, crypttab === modified file 'plugins.d/askpass-fifo.xml' --- plugins.d/askpass-fifo.xml 2009-01-04 21:54:55 +0000 +++ plugins.d/askpass-fifo.xml 2011-08-08 21:12:37 +0000 @@ -2,7 +2,7 @@ - + %common; ]> @@ -33,6 +33,7 @@ 2008 2009 + 2011 Teddy Hogeborn Björn Påhlsson @@ -148,6 +149,8 @@ SEE ALSO + intro + 8mandos, fifo 7, plugin-runner === modified file 'plugins.d/mandos-client.xml' --- plugins.d/mandos-client.xml 2011-07-31 13:05:34 +0000 +++ plugins.d/mandos-client.xml 2011-08-08 21:12:37 +0000 @@ -2,7 +2,7 @@ - + %common; ]> @@ -33,6 +33,7 @@ 2008 2009 + 2011 Teddy Hogeborn Björn Påhlsson @@ -535,6 +536,8 @@ SEE ALSO + intro + 8mandos, cryptsetup 8, crypttab === modified file 'plugins.d/password-prompt.xml' --- plugins.d/password-prompt.xml 2009-10-30 16:23:43 +0000 +++ plugins.d/password-prompt.xml 2011-08-08 21:12:37 +0000 @@ -2,7 +2,7 @@ - + %common; ]> @@ -33,6 +33,7 @@ 2008 2009 + 2011 Teddy Hogeborn Björn Påhlsson @@ -292,6 +293,8 @@ SEE ALSO + intro + 8mandos crypttab 5 mandos-client === modified file 'plugins.d/plymouth.xml' --- plugins.d/plymouth.xml 2011-02-27 17:26:35 +0000 +++ plugins.d/plymouth.xml 2011-08-08 21:12:37 +0000 @@ -2,7 +2,7 @@ - + %common; ]> @@ -261,6 +261,8 @@ SEE ALSO + intro + 8mandos, crypttab 5, plugin-runner === modified file 'plugins.d/splashy.xml' --- plugins.d/splashy.xml 2009-01-04 21:54:55 +0000 +++ plugins.d/splashy.xml 2011-08-08 21:12:37 +0000 @@ -2,7 +2,7 @@ - + %common; ]> @@ -33,6 +33,7 @@ 2008 2009 + 2011 Teddy Hogeborn Björn Påhlsson @@ -263,6 +264,8 @@ SEE ALSO + intro + 8mandos, crypttab 5, plugin-runner === modified file 'plugins.d/usplash.xml' --- plugins.d/usplash.xml 2009-01-04 21:54:55 +0000 +++ plugins.d/usplash.xml 2011-08-08 21:12:37 +0000 @@ -2,7 +2,7 @@ - + %common; ]> @@ -33,6 +33,7 @@ 2008 2009 + 2011 Teddy Hogeborn Björn Påhlsson @@ -277,6 +278,8 @@ SEE ALSO + intro + 8mandos, crypttab 5, fifo