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#!/usr/bin/perl
use strict;
use warnings;
# complete rewrite of the sshkeys-lint program. Usage has changed, see
# usage() function or run without arguments.
use lib $ENV{GL_LIBDIR};
use Gitolite::Common;
use Getopt::Long;
my $admin = 0;
my $quiet = 0;
my $help = 0;
GetOptions( 'admin|a=s' => \$admin, 'quiet|q' => \$quiet, 'help|h' => \$help );
use Data::Dumper;
$Data::Dumper::Deepcopy = 1;
$|++;
my $in_gl_section = 0;
my $warnings = 0;
my $KEYTYPE_REGEX = qr/\b(?:ssh-(?:rsa|dss|ed25519)|ecdsa-sha2-nistp(?:256|384|521))\b/;
sub msg {
my $warning = shift;
return if $quiet and not $warning;
$warnings++ if $warning;
print "sshkeys-lint: " . ( $warning ? "WARNING: " : "" ) . $_ for @_;
}
usage() if $help;
our @pubkeyfiles = @ARGV; @ARGV = ();
my $kd = "$ENV{HOME}/.gitolite/keydir";
if ( not @pubkeyfiles ) {
chomp( @pubkeyfiles = `find $kd -type f -name "*.pub" | sort` );
}
if ( -t STDIN ) {
@ARGV = ("$ENV{HOME}/.ssh/authorized_keys");
}
# ------------------------------------------------------------------------
my @authkeys;
my %seen_fprints;
my %pkf_by_fp;
msg 0, "==== checking authkeys file:\n";
fill_authkeys(); # uses up STDIN
if ($admin) {
my $fp = fprint("$admin.pub");
my $fpu = ( $fp && $seen_fprints{$fp}{user} || 'no access' );
# dbg("fpu = $fpu, admin=$admin");
#<<<
die "\t\t*** FATAL ***\n" .
"$admin.pub maps to $fpu, not $admin.\n" .
"You will not be able to access gitolite with this key.\n" .
"Look for the 'ssh troubleshooting' link in http://gitolite.com/gitolite/ssh.html.\n"
if $fpu ne "user $admin";
#>>>
}
msg 0, "==== checking pubkeys:\n" if @pubkeyfiles;
for my $pkf (@pubkeyfiles) {
# get the short name for the pubkey file
( my $pkfsn = $pkf ) =~ s(^$kd/)();
my $fp = fprint($pkf);
next unless $fp;
msg 1, "$pkfsn appears to be a COPY of $pkf_by_fp{$fp}\n" if $pkf_by_fp{$fp};
$pkf_by_fp{$fp} ||= $pkfsn;
my $fpu = ( $seen_fprints{$fp}{user} || 'no access' );
msg 0, "$pkfsn maps to $fpu\n";
}
if ($warnings) {
print "\n$warnings warnings found\n";
}
exit $warnings;
# ------------------------------------------------------------------------
sub fill_authkeys {
while (<>) {
my $seq = $.;
next if ak_comment($_); # also sets/clears $in_gl_section global
my $fp = fprint($_);
my $user = user($_);
check( $seq, $fp, $user );
$authkeys[$seq]{fprint} = $fp;
$authkeys[$seq]{ustatus} = $user;
}
}
sub check {
my ( $seq, $fp, $user ) = @_;
msg 1, "line $seq, $user key found *outside* gitolite section!\n"
if $user =~ /^user / and not $in_gl_section;
msg 1, "line $seq, $user key found *inside* gitolite section!\n"
if $user !~ /^user / and $in_gl_section;
if ( $seen_fprints{$fp} ) {
#<<<
msg 1, "authkeys line $seq ($user) will be ignored by sshd; " .
"same key found on line " .
$seen_fprints{$fp}{seq} . " (" .
$seen_fprints{$fp}{user} . ")\n";
return;
#>>>
}
$seen_fprints{$fp}{seq} = $seq;
$seen_fprints{$fp}{user} = $user;
}
sub user {
my $user = '';
$user ||= "user $1" if /^command=.*gitolite-shell (.*?)"/;
$user ||= "unknown command" if /^command/;
$user ||= "shell access" if /$KEYTYPE_REGEX/;
return $user;
}
sub ak_comment {
local $_ = shift;
$in_gl_section = 1 if /^# gitolite start/;
$in_gl_section = 0 if /^# gitolite end/;
die "gitosis? what's that?\n" if /^#.*gitosis/;
return /^\s*(#|$)/;
}
sub fprint {
local $_ = shift;
my ($fp, $output);
if ( /$KEYTYPE_REGEX/ ) {
# an actual key was passed. ssh-keygen CAN correctly handle options on
# the front of the key, so don't bother to strip them at all.
($fp, $output) = ssh_fingerprint_line($_);
} else {
# a filename was passed
($fp, $output) = ssh_fingerprint_file($_);
# include the line of input as well, as it won't always be included by the ssh-keygen command
warn "Bad line: $_\n" unless $fp;
}
# sshkeys-lint should only be run by a trusted admin, so we can give the output here.
warn "$output\n" unless $fp;
return $fp;
}
# ------------------------------------------------------------------------
=for usage
Usage: gitolite sshkeys-lint [-q] [optional list of pubkey filenames]
(optionally, STDIN can be a pipe or redirected from a file; see below)
Look for potential problems in ssh keys.
sshkeys-lint expects:
- the contents of an authorized_keys file via STDIN, otherwise it uses
\$HOME/.ssh/authorized_keys
- one or more pubkey filenames as arguments, otherwise it uses all the keys
found (recursively) in \$HOME/.gitolite/keydir
The '-q' option will print only warnings instead of all mappings.
Note that this runs ssh-keygen -l for each line in the authkeys file and each
pubkey in the argument list, so be wary of running it on something huge. This
is meant for troubleshooting.
=cut
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