sshkeys-lint total rewrite, and gl-setup now uses it

...in "admin check" mode
This commit is contained in:
Sitaram Chamarty 2011-11-13 17:37:01 +05:30
parent ec93fc7601
commit c5f342a835
2 changed files with 158 additions and 89 deletions

View file

@ -136,3 +136,9 @@ gl-compile-conf -q
# now that the admin repo is created, you have to set the hooks properly; best # now that the admin repo is created, you have to set the hooks properly; best
# do it by running install again # do it by running install again
gl-install -q gl-install -q
# ----
# the never-ending quest to help with bloody ssh issues...
cd $GL_ADMINDIR/keydir
[ -n "$pubkey_file" ] && $GL_BINDIR/sshkeys-lint < $HOME/.ssh/authorized_keys -q -a $admin_name

View file

@ -1,109 +1,172 @@
#!/usr/bin/perl -w #!/usr/bin/perl
use strict; use strict;
our (%users, %linenos, %pubkeyfiles); use warnings;
my $thisbin = $0; # complete rewrite of the sshkeys-lint program. Usage has changed, see
$thisbin = "$ENV{PWD}/$thisbin" unless $thisbin =~ /^\//; # usage() function or run without arguments.
usage() unless $ARGV[0] and -f $ARGV[0]; use Getopt::Long;
my @authlines = filelines($ARGV[0]); my $admin = 0;
my $lineno = 0; my $quiet = 0;
for (@authlines) GetOptions('admin|a=s' => \$admin, 'quiet|q' => \$quiet);
{
$lineno++;
my $in_gs = (/^# gitolite start/ .. /^# gitolite end/);
next if /\# gitolite (start|end)/;
my $user = ""; use Data::Dumper;
$user = "host $1" if /^command=.*gl-mirror-shell (\S+?)"/; $Data::Dumper::Deepcopy = 1;
$user = "user $1" if /^command=.*gl-auth-command (\S+?)"/; $|++;
$user = "shell user $1" if /^command=.*gl-auth-command -s (\S+?)"/;
die "line $lineno: unrecognised line\n" unless /^(?:command=".*(?:gl-mirror-shell|gl-auth-command(?: -s)?) (?:\S+?)"\S+ )?(?:ssh-rsa|ssh-dss) (\S+)/; my $in_gl_section = 0;
my $key = $1; my $warnings = 0;
if ($linenos{$key}) {
warn "authkeys file line $lineno is repeat of line $linenos{$key}, will be ignored by server sshd\n"; sub dbg {
next; use Data::Dumper;
for my $i (@_) {
print STDERR "DBG: " . Dumper($i);
} }
$linenos{$key} = $lineno;
$users{$key} = ($user ? "maps to $user" : "gets you a command line");
} }
print "\n"; sub msg {
my $warning = shift;
return if $quiet and not $warning;
$warnings++ if $warning;
print "sshkeys-lint: " . ( $warning ? "WARNING: " : "" ) . $_ for @_;
}
# all *.pub in current dir should be exactly one line, starting with ssh-rsa @ARGV or not -t or usage();
# or ssh-dss our @pubkeyfiles = @ARGV; @ARGV = ();
my @pubkeys = sort glob("*.pub"); # ------------------------------------------------------------------------
die "no *.pub files here\n" unless @pubkeys;
for my $pub (@pubkeys) { my @authkeys;
my @lines = grep { ! /^\s*#/ } filelines($pub); my %seen_fprints;
die "$pub has more than one line\n" if @lines > 1; my %pkf_by_fp;
die "$pub does not start with ssh-rsa or ssh-dss\n" unless $lines[0] =~ /^(?:ssh-rsa|ssh-dss) (\S+)/; msg 0, "==== checking authkeys file:\n";
my $key = $1; fill_authkeys(); # uses up STDIN
print "$pub seems to be A COPY OF $pubkeyfiles{$key}\n" if $pubkeyfiles{$key};
$pubkeyfiles{$key} ||= $pub; if ($admin) {
if ($users{$key}) { my $fp = fprint("$admin.pub");
print "$pub $users{$key}\n"; my $fpu = ( $seen_fprints{$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://sitaramc.github.com/gitolite/.\n"
if $fpu ne "user $admin";
}
msg 0, "==== checking pubkeys:\n" if @pubkeyfiles;
for my $pkf (@pubkeyfiles) {
my $fp = fprint($pkf);
msg 1, "$pkf appears to be a COPY of $pkf_by_fp{$fp}\n" if $pkf_by_fp{$fp};
$pkf_by_fp{$fp} ||= $pkf;
my $fpu = ( $seen_fprints{$fp}{user} || 'no access' );
msg 0, "$pkf 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=.*gl-auth-command (.*?)"/;
$user ||= "host $1" if /^command=.*gl-mirror-shell (.*?)"/;
$user ||= "unknown command" if /^command/;
$user ||= "shell access" if /^ssh-(rsa|dss)/;
return $user;
}
sub ak_comment {
my $_ = 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 {
my $_ = shift;
my ($fh, $tempfn, $in);
if (/ssh-(dss|rsa) /) {
# an actual key was passed. Since ssh-keygen requires an actual file,
# make a temp file to take the data and pass on to ssh-keygen
s/^.* (ssh-dss|ssh-rsa)/$1/;
use File::Temp qw(tempfile);
($fh, $tempfn) = tempfile();
$in = $tempfn;
print $fh $_;
close $fh;
} else { } else {
print "$pub has NO ACCESS to the server\n"; # a filename was passed
$in = $_;
} }
# dbg("in = $in");
-f $in or die "file not found: $in\n";
open($fh, "ssh-keygen -l -f $in |") or die "could not fork: $!\n";
my $fp = <$fh>;
# dbg("fp = $fp");
close $fh;
unlink $tempfn if $tempfn;
die "fprint failed\n" unless $fp =~ /([0-9a-f][0-9a-f](:[0-9a-f][0-9a-f])+)/;
return $1;
} }
print <<INFO; # ------------------------------------------------------------------------
sub usage {
print <<EOF;
==== sshkeys-lint expects
- the contents of an authorized_keys file via STDIN
- one or more pubkey filenames as arguments
Git operations using a pubkey that gets you a command line will BYPASS sample use to check all keys on gitolite server:
gitolite completely. This means: cd ~/.gitolite/keydir
cat ~/.ssh/authorized_keys | sshkeys-lint `find . -name "*.pub"`
# or supply only one pubkey file to check only that:
cat ~/.ssh/authorized_keys | sshkeys-lint YourName.pub
- using "git clone git\@server:reponame" will get you the "does not appear to Note that it runs ssh-keygen -l for each line in the authkeys file and each
be a git repository" message pubkey in the argument list, so be wary of running it on something huge. This
- using "git clone git\@server:repositories/reponame" [assuming default value is meant for troubleshooting.
of \$REPO_BASE) will work but subsequent push will fail
----
Now you know what pubkey gets you what access.
To see what key is *actually* being used when you run your commands, try "ssh
-v git\@server" or "ssh -v gitolite", and look for a line saying "Offering
public key". If there are more than one such lines, the last one is what
counts.
If at any time you are asked for a password (password, not passphrase; see
doc/6 for the difference, if needed), then none of this applies anyway.
INFO
sub filelines
{
my $f;
my $fn = shift;
open ($f, "<", $fn) or die "open $fn failed: $!\n";
return <$f>;
}
sub usage
{
print STDERR <<EOF;
On your *client*:
- copy the server's ~/.ssh/authorized_keys file to your *client*'s
/tmp/foo (maybe using "scp" or whatever)
- cd to the ~/.ssh directory (which contains all the pub keys this client
can use)
- run "$thisbin /tmp/foo"
Note: people who have so many keypairs they keep them in *sub*-directories of
~/.ssh [you know who you are ;-)] can figure it out themselves; you clearly
know enough about ssh not to need my help!
EOF EOF
exit 1;
exit 1;
} }