gitolite/gl-auth-command
2009-08-25 11:06:03 +05:30

111 lines
3.8 KiB
Perl
Executable file

#!/usr/bin/perl -w
use strict;
# === auth-command ===
# the command that GL users actually run
# part of the gitosis-lite (GL) suite
# how run: via sshd, being listed in "command=" in ssh authkeys
# when: every login by a GL user
# input: $1 is GL username, plus $SSH_ORIGINAL_COMMAND
# output:
# security:
# - currently, we just make some basic checks, copied from gitosis
# robustness:
# other notes:
# ----------------------------------------------------------------------------
# common definitions
# ----------------------------------------------------------------------------
our $GL_ADMINDIR;
our $GL_CONF;
our $GL_KEYDIR;
our $GL_CONF_COMPILED;
our $REPO_BASE;
our %repos;
my $glrc = $ENV{HOME} . "/.gitosis-lite.rc";
unless (my $ret = do $glrc)
{
die "parse $glrc failed: $@" if $@;
die "couldn't do $glrc: $!" unless defined $ret;
die "couldn't run $glrc" unless $ret;
}
die "couldnt do perms file" unless (my $ret = do $GL_CONF_COMPILED);
# ----------------------------------------------------------------------------
# definitions specific to this program
# ----------------------------------------------------------------------------
my $R_COMMANDS=qr/^git[ -]upload-pack$/;
my $W_COMMANDS=qr/^git[ -]receive-pack$/;
my $REPONAME_PATT=qr(^[0-9a-zA-Z][0-9a-zA-Z._/-]*$); # very simple pattern
# ----------------------------------------------------------------------------
# start...
# ----------------------------------------------------------------------------
# first, fix the biggest gripe I have with gitosis, a 1-line change
my $user=$ENV{GL_USER}=shift; # there; now that's available everywhere!
# ----------------------------------------------------------------------------
# sanity checks on SSH_ORIGINAL_COMMAND
# ----------------------------------------------------------------------------
# SSH_ORIGINAL_COMMAND must exist. Since we also captured $user, we print
# that in the message so people saying "ssh git@server" can see which gitosis
# user he is being recognised as
my $cmd = $ENV{SSH_ORIGINAL_COMMAND}
or die "no SSH_ORIGINAL_COMMAND? I'm not a shell, $user!";
# we don't like newlines or semicolons in SSH_ORIGINAL_COMMAND
die "$cmd??? you're a funny guy..."
if $cmd =~ /[;\n]/;
# split into command and arguments; the pattern allows old style as well as
# new style: "git-subcommand arg" or "git subcommand arg", just like gitosis
# does, although I'm not sure how necessary that is
#
# keep in mind this is how git sends across the command:
# git-receive-pack 'reponame.git'
# including the single quotes
my ($verb, $repo) = ($cmd =~ /^\s*(git\s+\S+|\S+)\s+'(.*).git'/);
die "$verb? I don't do odd jobs, sorry..."
unless $verb =~ $R_COMMANDS or $verb =~ $W_COMMANDS;
die "I don't like the look of $repo, sorry!"
unless $repo =~ $REPONAME_PATT;
# ----------------------------------------------------------------------------
# first level permissions check
# ----------------------------------------------------------------------------
# we know the user and repo; we just need to know what perm he's trying
my $perm = ($verb =~ $R_COMMANDS ? 'R' : 'W');
die "access denied" unless $repos{$repo}{$perm}{$user};
# ----------------------------------------------------------------------------
# over to git now
# ----------------------------------------------------------------------------
# ( but first save the reponame; we can save some time later in the hook )
$ENV{GL_REPO}=$repo;
# if log failure isn't important enough to block access, get rid of all the
# error checking
open my $log_fh, ">>", "$GL_ADMINDIR/log"
or die "open log failed: $!";
print $log_fh "\n", scalar(localtime), " $ENV{SSH_ORIGINAL_COMMAND} $user\n";
close $log_fh or die "close log failed: $!";
$repo = "'$REPO_BASE/$repo.git'";
exec("git", "shell", "-c", "$verb $repo");