Try to make our PGP signing more useful:

* All the PuTTY tools for Windows and Unix now contain the fingerprints of
   the Master Keys. The method for accessing them is crude but universal:
   a new "-pgpfp" command-line option. (Except Unix PuTTYgen, which takes
   "--pgpfp" just to be awkward.)

 * Move the key policy discussion from putty-website/keys.html to
   putty/doc/pgpkeys.but, and autogenerate the former from the latter.
   Also tweak the text somewhat and include the fingerprints of the
   Master Keys themselves.
   (I've merged the existing autogeneration scripts into a single new
   one; I've left the old scripts and keys.html around until such time
   as the webmonster reviews the changes and plumbs in the new script;
   he should remove the old files then.)

[originally from svn r5524]
[this svn revision also touched putty-website]

doc/Makefile

@@ -35,7 +35,7 @@ VERSIONIDS=vids
 endif
 
 CHAPTERS := $(SITE) blurb intro gs using config pscp psftp plink pubkey
-CHAPTERS += pageant errors faq feedback licence udp
+CHAPTERS += pageant errors faq feedback licence udp pgpkeys
 CHAPTERS += index $(VERSIONIDS)
 
 INPUTS = $(patsubst %,%.but,$(CHAPTERS))

doc/index.but

@@ -109,6 +109,7 @@ saved sessions from
 \IM{-1} \c{-1} command-line option
 \IM{-2} \c{-2} command-line option
 \IM{-i} \c{-i} command-line option
+\IM{-pgpfp} \c{-pgpfp} command-line option
 
 \IM{removing registry entries} removing registry entries
 \IM{removing registry entries} registry entries, removing

doc/man-pg.but

@@ -142,6 +142,18 @@ fingerprint. Otherwise, the \c{\-o} option is required.
 
 \dd Synonym for \q{\cw{-O public}}.
 
+The following options do not run PuTTYgen as normal, but print
+informational messages and then quit:
+
+\dt \cw{\-\-help}
+
+\dd Display a message summarizing the available options.
+
+\dt \cw{\-\-pgpfp}
+
+\dd Display the fingerprints of the PuTTY PGP Master Keys, to aid
+in verifying new files released by the PuTTY team.
+
 \S{puttygen-manpage-examples} EXAMPLES
 
 To generate an SSH-2 RSA key pair and save it in PuTTY's own format

doc/man-pl.but

@@ -23,6 +23,11 @@ The command-line options supported by \cw{plink} are:
 
 \dd Show version information and exit.
 
+\dt \cw{-pgpfp}
+
+\dd Display the fingerprints of the PuTTY PGP Master Keys and exit,
+to aid in verifying new files released by the PuTTY team.
+
 \dt \cw{-v}
 
 \dd Show verbose messages.

doc/man-pscp.but

@@ -28,6 +28,11 @@ The command-line options supported by \e{pscp} are:
 
 \dd Show version information and exit.
 
+\dt \cw{-pgpfp}
+
+\dd Display the fingerprints of the PuTTY PGP Master Keys and exit,
+to aid in verifying new files released by the PuTTY team.
+
 \dt \cw{-ls}
 
 \dd Remote directory listing.

doc/man-psft.but

@@ -24,6 +24,11 @@ The command-line options supported by \cw{psftp} are:
 
 \dd Show version information and exit.
 
+\dt \cw{-pgpfp}
+
+\dd Display the fingerprints of the PuTTY PGP Master Keys and exit,
+to aid in verifying new files released by the PuTTY team.
+
 \dt \cw{-b} \e{batchfile}
 
 \dd Use specified batchfile.

doc/man-ptel.but

@@ -149,6 +149,11 @@ keys.
 
 \dd Display a message summarizing the available options.
 
+\dt \cw{\-pgpfp}
+
+\dd Display the fingerprints of the PuTTY PGP Master Keys, to aid
+in verifying new files released by the PuTTY team.
+
 \dt \cw{\-load} \e{session}
 
 \dd Load a saved session by name. This allows you to run a saved session

doc/man-pter.but

@@ -205,6 +205,11 @@ example:
 
 \dd Display a message summarizing the available options.
 
+\dt \cw{\-pgpfp}
+
+\dd Display the fingerprints of the PuTTY PGP Master Keys, to aid
+in verifying new files released by the PuTTY team.
+
 \S{pterm-manpage-x-resources} X RESOURCES
 
 \cw{pterm} can be more completely configured by means of X

doc/man-putt.but

@@ -149,6 +149,11 @@ keys.
 
 \dd Display a message summarizing the available options.
 
+\dt \cw{\-pgpfp}
+
+\dd Display the fingerprints of the PuTTY PGP Master Keys, to aid
+in verifying new files released by the PuTTY team.
+
 \dt \cw{\-load} \e{session}
 
 \dd Load a saved session by name. This allows you to run a saved session

doc/pgpkeys.but

@@ -0,0 +1,157 @@
+\define{versionidpgpkeys} \versionid $Id$
+
+\A{pgpkeys} PuTTY download keys and signatures
+
+\cfg{winhelp-topic}{pgpfingerprints}
+
+We create \i{PGP signatures} for all the PuTTY
+files distributed from our web site, so that users can be confident
+that the files have not been tampered with. Here we identify
+our public keys, and explain our signature policy so you can have an
+accurate idea of what each signature guarantees.
+This description is provided as both a web page on the PuTTY site, and
+an appendix in the PuTTY manual.
+
+As of the next release, all of the PuTTY executables will contain
+\#{XXX-REMOVE-BEFORE-RELEASE: fix this up for forthcoming release
+As of release 0.58, all of the PuTTY executables contain}
+fingerprint material (usually accessed via the \i\c{-pgpfp}
+command-line option), such that if you have an executable you trust,
+you can use it to establish a trust path, for instance to a newer
+version downloaded from the Internet.
+
+(Note that none of the keys, signatures, etc mentioned here have
+anything to do with keys used with SSH - they are purely for verifying
+the origin of files distributed by the PuTTY team.)
+
+\H{pgpkeys-pubkey} Public keys
+
+We supply two complete sets of keys. We supply a set of RSA keys,
+compatible with both \W{http://www.gnupg.org/}{GnuPG} and PGP2,
+and also a set of DSA keys compatible with GnuPG.
+
+In each format, we have three keys:
+
+\b A Development Snapshots key, used to sign the nightly builds.
+
+\b A Releases key, used to sign actual releases.
+
+\b A Master Key. The Master Key is used to sign the other two keys, and
+they sign it in return.
+
+Therefore, we have six public keys in total:
+
+\b RSA:
+
+\lcont{
+
+\b \W{http://www.chiark.greenend.org.uk/~sgtatham/putty/keys/master-rsa.asc}{Master Key}
+
+\lcont{
+1024-bit; fingerprint:
+\cw{8F\_15\_97\_DA\_25\_30\_AB\_0D\_\_88\_D1\_92\_54\_11\_CF\_0C\_4C}
+}
+
+\b \W{http://www.chiark.greenend.org.uk/~sgtatham/putty/keys/release-rsa.asc}{Release key}
+
+\b \W{http://www.chiark.greenend.org.uk/~sgtatham/putty/keys/snapshot-rsa.asc}{Snapshot key}
+
+}
+
+\b DSA:
+
+\lcont{
+
+\b \W{http://www.chiark.greenend.org.uk/~sgtatham/putty/keys/master-dsa.asc}{Master Key}
+
+\lcont{
+1024-bit; fingerprint:
+\cw{313C\_3E76\_4B74\_C2C5\_F2AE\_\_83A8\_4F5E\_6DF5\_6A93\_B34E}
+}
+
+\b \W{http://www.chiark.greenend.org.uk/~sgtatham/putty/keys/release-dsa.asc}{Release key}
+
+\b \W{http://www.chiark.greenend.org.uk/~sgtatham/putty/keys/snapshot-dsa.asc}{Snapshot key}
+
+}
+
+\H{pgpkeys-security} Security details
+
+The various keys have various different security levels. This
+section explains what those security levels are, and how far you can
+expect to trust each key.
+
+\S{pgpkeys-snapshot} The Development Snapshots keys
+
+These keys are stored \e{without passphrases}. This is
+necessary, because the snapshots are generated every night without
+human intervention, so nobody would be able to type a passphrase.
+
+The actual snapshots are built on a team member's home Windows box.
+The keys themselves are stored on an independently run Unix box
+(the same one that hosts our Subversion repository). After
+being built, the binaries are uploaded to this Unix box and then
+signed automatically.
+
+Therefore, a signature from one of the Development Snapshots keys
+\e{DOES} protect you against:
+
+\b People tampering with the PuTTY binaries between the PuTTY web site
+and you.
+
+But it \e{DOES NOT} protect you against:
+
+\b People tampering with the binaries before they are uploaded to the
+independent Unix box.
+
+\b The sysadmin of the independent Unix box using his root privilege to
+steal the private keys and abuse them, or tampering with the
+binaries before they are signed.
+
+\b Somebody getting root on the Unix box.
+
+Of course, we don't believe any of those things is very likely. We
+know our sysadmin personally and trust him (both to be competent and
+to be non-malicious), and we take all reasonable precautions to
+guard the build machine. But when you see a signature, you should
+always be certain of precisely what it guarantees and precisely what
+it does not.
+
+\S{pgpkeys-release} The Releases keys
+
+The Release keys have passphrases and we can be more careful about
+how we use them.
+
+The Release keys are kept safe on the developers' own local
+machines, and only used to sign releases that have been built by
+hand. A signature from a Release key protects you from almost any
+plausible attack.
+
+(Some of the developers' machines have cable modem connections and
+might in theory be crackable, but of course the private keys are
+still encrypted, so the crack would have to go unnoticed for long
+enough to steal a passphrase.)
+
+\S{pgpkeys-master} The Master Keys
+
+The Master Keys sign almost nothing. Their purpose is to bind the
+other keys together and certify that they are all owned by the same
+people and part of the same integrated setup. The only signatures
+produced by the Master Keys, \e{ever}, should be the signatures
+on the other keys.
+
+We intend to arrange for the Master Keys to sign each other, to
+certify that the DSA keys and RSA keys are part of the same setup.
+We have not yet got round to this at the time of writing.
+
+We have collected a few third-party signatures on the Master Keys,
+in order to increase the chances that you can find a suitable trust
+path to them. We intend to collect more. (Note that the keys on the
+keyservers appear to have also collected some signatures from people
+who haven't performed any verification of the Master Keys.) 
+
+We have uploaded our various keys to public keyservers, so that
+even if you don't know any of the people who have signed our
+keys, you can still be reasonably confident that an attacker would
+find it hard to substitute fake keys on all the public keyservers at
+once.

doc/plink.but

@@ -47,7 +47,8 @@ use Plink:
 \c Usage: plink [options] [user@]host [command]
 \c        ("host" can also be a PuTTY saved session name)
 \c Options:
-\c   -V        print version information
+\c   -V        print version information and exit
+\c   -pgpfp    print PGP key fingerprints and exit
 \c   -v        show verbose messages
 \c   -load sessname  Load settings from saved session
 \c   -ssh -telnet -rlogin -raw

doc/pscp.but

@@ -46,6 +46,8 @@ use PSCP:
 \c        pscp [options] source [source...] [user@]host:target
 \c        pscp [options] -ls [user@]host:filespec
 \c Options:
+\c   -V        print version information and exit
+\c   -pgpfp    print PGP key fingerprints and exit
 \c   -p        preserve file attributes
 \c   -q        quiet, don't show statistics
 \c   -r        copy directories recursively
@@ -60,7 +62,6 @@ use PSCP:
 \c   -i key    private key file for authentication
 \c   -batch    disable all interactive prompts
 \c   -unsafe   allow server-side wildcards (DANGEROUS)
-\c   -V        print version information
 \c   -sftp     force use of SFTP protocol
 \c   -scp      force use of SCP protocol
 

doc/using.but

@@ -782,3 +782,9 @@ For general information on \i{public-key authentication}, see
 This option is equivalent to the \q{Private key file for
 authentication} box in the Auth panel of the PuTTY configuration box
 (see \k{config-ssh-privkey}).
+
+\S2{using-cmdline-pgpfp} \i\c{-pgpfp}: display PGP key fingerprints
+
+This option causes the PuTTY tools not to run as normal, but instead
+to display the fingerprints of the PuTTY PGP Master Keys, in order to
+aid with verifying new versions. See \k{pgpkeys} for more information.