Re: perl scripts for PGP

23 Jan 1993

...
...
Marc,
when you were here in DC, you mentioned some perl scripts that processed
PGP output. Can you please send me a copy?
yeah, and I'm cc'ing cypherpunks, since I think you all might be
interested, too.

This script has three functions.  All take the output of pgp -kvv as
input.

1) it "inverts" a pgp file, listing all the keys signed by a given
key, as compared to giving all the keys which have signed a given key.

2) given -kvv output (and it can merge several files of input
automatically, since it hashes on key id), it lists all the keys which
you (or any other key) have a path of signatures to, and the length of
the shortest such path.  So, the specified key has a path length 0.
All keys signed by that key have a path length 1, all keys signed by
those keys have path length 2, etc.

3) Optionally, it will list one of these paths for each key you can
reach.  There may be many paths, so this is only for interest; to
enumerate all paths would be painful.

The most interesting use for this script is to see what your "radius"
is (maximum distance to any key), and to see how big your "world" is.
Needless to say, I wouldn't trust keys which have a long path length
too much, if at all.  There are 155 keys in my "world" (out of a
keyring of about 350).  My current radius is 7.  Tom, if you're in
Boston anytime, my radius would decrease to 5 if I signed your key.
That would be cool :-)

		Marc

#!/afs/athena/contrib/perl/perl

#
# $Id: pgputil.pl,v 1.7 1993/01/23 07:29:27 marc Exp $
#

## pgputil.pl. Copyright 1993, Marc Horowitz <marc@mit.edu>
## 
## This program may be freely redistributed and used as long as the RCS
## Id, copyright, and this message are left intact.  It may also be used
## as the basis for other programs, as long as this program is
## acknowledged in the code and documentation, and it is made clear that
## the new program is a derivative work, and not the original.  Although
## not required, it would be nice if any modifications were sent back to
## me.

$save = "";

sub next {
    local($ret);

    return() if !defined($save);

    while(1) {
	$_ = $save || <>;
	$save = "";
	if (! $_) {
	    undef $save;
	    return($ret);
	} elsif (/^\s/) {
	    $ret .= $_;
	} elsif ($ret) {
	    $save = $_;
	    return($ret);
	} else {
	    $ret = $_;
	}
    }
}

sub parsekvv {
    local($keyid,$ring,$lastpub);

    while($_ = &next()) {
	if (/^Key ring:\s+'(.*)'$/) {
	    $ring = $1;
	} elsif (m!^pub\s+\d+/([0-9A-F]+)\s+\d+/\d+/\d+\s+!) {
	    $lastpub = $1;
	    $publine{$lastpub} = $_;
	    ($pubindent{$lastpub} = $_) =~ s!\d{4}/\d\d/\d\d!$&  !;
	} elsif (/^sig\s+([0-9A-F]+)/) {
	    $keyid = $1;
	    $sigindent{$keyid} = $_;
	    ($sigline{$keyid} = $_) =~ s/^(sig\s+[0-9A-F]{6})\s\s/$1/;
	    $siglist{$keyid} .= $lastpub." " if $siglist{$keyid} !~ /$lastpub/;
	}
    }
}

sub findsigned {
    local($level,@from) = @_;
    local($tmp,@next);

    foreach $hash (@from) {
	next if (defined $depth{$hash});

	$depth{$hash} = $level;
	for $nexth (split(' ',$siglist{$hash})) {
	    push(@next,$nexth);
	    $signedby{$nexth} = $hash if !defined $signedby{$nexth};
	}
    }

    if (@next) {
	&findsigned($level+1,@next);
    }
}

($zero = $0) =~ s!^.*/([^/]+)$!$1!;

sub usage {
    die  "usage: $zero signators [ file ... ]\n"
	,"       $zero recurse [ -v ] <keyid> [ file ... ]\n";
}

sub signators {
    &parsekvv();

    print "Type bits/keyID   Date       User ID\n";

    foreach $hash (keys %siglist) {
	next if ($sigline{$hash} =~ /Unknown signator/);

	print $sigline{$hash};
	foreach $pubhash (split(' ',$siglist{$hash})) {
	    print $pubindent{$pubhash};
	}
    }
}

sub recurse {
    for (@ARGV) {
	if (/^-v/) {
	    $verbose++;
	} else {
	    push(@newargv, $_);
	}
    }
    @ARGV = @newargv;
    $keyid = shift(@ARGV);

    if ($keyid !~ /^[0-9A-F]{6}$/) { &usage; }

    &parsekvv();
    $signedby{$keyid} = "";
    &findsigned(0, $keyid);

    foreach $pubhash (keys %depth) {
	$out{sprintf("%02d%s",$depth{$pubhash},$pubhash)} = 
	    sprintf("%2d %s",$depth{$pubhash},$publine{$pubhash});
    }

    foreach $k (sort keys %out) {
	print $out{$k};

	if ($verbose) {
	    $sig = $signedby{substr($k,2,6)};

	    while($sig) {
		($x = $pubindent{$sig}) =~ 
		print "   ",$x;
		$sig = $signedby{$sig};
	    }
	}
    }
}

## dispatch

$cmd = shift(@ARGV) || &usage();

if ($cmd =~ /^s/) {
    &signators();
} elsif ($cmd =~ /^r/) {
    &recurse();
} else {
    &usage();
}