#!perl

# Perl c_rehash script, scan all files in a directory
# and add symbolic links to their hash values.

my $openssl;

my $dir = "/usr/lib/ssl";
my $prefix = "/usr";

if(defined $ENV{OPENSSL}) {
        $openssl = $ENV{OPENSSL};
} else {
        $openssl = "openssl";
        $ENV{OPENSSL} = $openssl;
}

my $pwd;
eval "require Cwd";
if (defined(&Cwd::getcwd)) {
        $pwd=Cwd::getcwd();
} else {
        $pwd=`pwd`; chomp($pwd);
}
my $path_delim = ($pwd =~ /^[a-z]\:/i) ? ';' : ':'; # DOS/Win32 or Unix delimiter?

$ENV{PATH} = "$prefix/bin" . ($ENV{PATH} ? $path_delim . $ENV{PATH} : ""); # prefix our path

if(! -x $openssl) {
        my $found = 0;
        foreach (split /$path_delim/, $ENV{PATH}) {
                if(-x "$_/$openssl") {
                        $found = 1;
                        $openssl = "$_/$openssl";
                        last;
                }       
        }
        if($found == 0) {
                print STDERR "c_rehash: rehashing skipped ('openssl' program not available)\n";
                exit 0;
        }
}

if(@ARGV) {
        @dirlist = @ARGV;
} elsif($ENV{SSL_CERT_DIR}) {
        @dirlist = split /$path_delim/, $ENV{SSL_CERT_DIR};
} else {
        $dirlist[0] = "$dir/certs";
}

if (-d $dirlist[0]) {
        chdir $dirlist[0];
        $openssl="$pwd/$openssl" if (!-x $openssl);
        chdir $pwd;
}

foreach (@dirlist) {
        if(-d $_ and -w $_) {
                hash_dir($_);
        }
}

sub hash_dir {
        my %hashlist;
        print "Doing $_[0]\n";
        chdir $_[0];
        opendir(DIR, ".");
        my @flist = readdir(DIR);
        # Delete any existing symbolic links
        foreach (grep {/^[\da-f]+\.r{0,1}\d+$/} @flist) {
                if(-l $_) {
                        unlink $_;
                }
        }
        closedir DIR;
        FILE: foreach $fname (grep {/\.pem$|\.crt$/} @flist) {
                # Check to see if certificates and/or CRLs present.
                my ($cert, $crl) = check_file($fname);
                if(!$cert && !$crl) {
                        ($cert, $crl) = check_file("$openssl x509 -in \"$fname\" -inform der  -outform pem | ");
                        if(!$cert && !$crl) {
                                print STDERR "WARNING: $fname does not contain a certificate or CRL: skipping\n";
                                next;
                        }
                }
                link_hash_cert($fname) if($cert);
                link_hash_cert_old($fname) if($cert);
                link_hash_crl($fname) if($crl);
        }
}

sub check_file {
        my ($is_cert, $is_crl) = (0,0);
        my $fname = $_[0];
        open IN, $fname;
        while(<IN>) {
                if(/^-----BEGIN (.*)-----/) {
                        my $hdr = $1;
                        if($hdr =~ /^(X509 |TRUSTED |)CERTIFICATE$/) {
                                $is_cert = 1;
                                last if($is_crl);
                        } elsif($hdr eq "X509 CRL") {
                                $is_crl = 1;
                                last if($is_cert);
                        }
                }
        }
        close IN;
        return ($is_cert, $is_crl);
}


# Link a certificate to its subject name hash value, each hash is of
# the form <hash>.<n> where n is an integer. If the hash value already exists
# then we need to up the value of n, unless its a duplicate in which
# case we skip the link. We check for duplicates by comparing the
# certificate fingerprints

use File::Temp qw/ tempfile /;
sub link_hash_cert {
                my $fname = $_[0];
                my $hashopt = $_[1] || '-subject_hash';
                $fname =~ s/'/'\\''/g;
                open my $in_fh, '<', $fname or die "can't open $fname for read";
                my $cert = eval {local $/ = undef; <$in_fh>};
                close $in_fh;
                OUTERLOOP:
                while ($cert =~ /^(-----BEGIN CERTIFICATE-----.*?-----END CERTIFICATE-----)$/gms)
                {
                   my $part = $1;
                   my (undef, $tfile) = tempfile();
                   #my $tfile = `tempfile`;
                   chomp $tfile;
                   open my $tfile_fh, '>', $tfile or die "can't open $tfile for write";
                   print {$tfile_fh} "$part\n";
                   close $tfile_fh;

                   my ($hash, $fprint) = `"$openssl" x509 $hashopt -fingerprint -noout -in "$tfile"`;
                   chomp $hash;
                   chomp $fprint;
                   $fprint =~ s/^.*=//;
                   $fprint =~ tr/://d;
                   my $suffix = 0;
                   # Search for an unused hash filename
                   while(exists $hashlist{"$hash.$suffix"}) {
                           # Hash matches: if fingerprint matches its a duplicate cert
                           if($hashlist{"$hash.$suffix"} eq $fprint) {
                                   print STDERR "WARNING: Skipping duplicate certificate $fname\n";
                                   unlink $tfile;
                                   next OUTERLOOP;
                           }
                           $suffix++;
                   }
                   $hash .= ".$suffix";
                   print "$fname => $hash\n";
                   $symlink_exists=eval {symlink("",""); 1};
                   if ($symlink_exists) {
                           symlink $fname, $hash;
                   } else {
                           open IN,"<$tfile" or die "can't open $tfile for read";
                           open OUT,">$hash" or die "can't open $hash for write";
                           print OUT <IN>;      # does the job for small text files
                           close OUT;
                           close IN;
                   }
                   $hashlist{$hash} = $fprint;
                   unlink $tfile;
                } ## end while ($cert =~ /^(-----BEGIN ...
}

sub link_hash_cert_old {
                link_hash_cert($_[0], '-subject_hash_old');
}

# Same as above except for a CRL. CRL links are of the form <hash>.r<n>

sub link_hash_crl {
                my $fname = $_[0];
                $fname =~ s/'/'\\''/g;
                my ($hash, $fprint) = `"$openssl" crl -hash -fingerprint -noout -in '$fname'`;
                if(!$hash || !$fprint) {
                        ($hash, $fprint) = `"$openssl" crl -hash -fingerprint -noout -in '$fname' -inform der`;
                }
                chomp $hash;
                chomp $fprint;
                $fprint =~ s/^.*=//;
                $fprint =~ tr/://d;
                my $suffix = 0;
                # Search for an unused hash filename
                while(exists $hashlist{"$hash.r$suffix"}) {
                        # Hash matches: if fingerprint matches its a duplicate cert
                        if($hashlist{"$hash.r$suffix"} eq $fprint) {
                                print STDERR "WARNING: Skipping duplicate CRL $fname\n";
                                return;
                        }
                        $suffix++;
                }
                $hash .= ".r$suffix";
                print "$fname => $hash\n";
                $symlink_exists=eval {symlink("",""); 1};
                if ($symlink_exists) {
                        symlink $fname, $hash;
                } else {
                        system ("cp", $fname, $hash);
                }
                $hashlist{$hash} = $fprint;
}