Modify checkhash.pl so it can be run standalone or included as a funtion

in another perl script.

util/checkhash.pl

@@ -1,5 +1,20 @@
 #!/usr/local/bin/perl -w
 
+my $package = caller;
+
+if (!(defined $package))
+	{
+	my $retval = check_hashes(@ARGV);
+	exit $retval;
+	}
+
+1;
+
+sub check_hashes
+	{
+
+	my @args = @_;
+
 	my $change_dir = "";
 	my $check_program = "sha1/fips_standalone_sha1";
 
@@ -12,47 +27,48 @@ my $recurse = 0;
 
 	my @fingerprint_files;
 
-while (@ARGV)
+	while (@args)
 		{
-	my $arg = $ARGV[0];
+		my $arg = $args[0];
 		if ($arg eq "-chdir")
 			{
-		shift @ARGV;
+			shift @args;
-		$change_dir = shift @ARGV;
+			$change_dir = shift @args;
 			}
 		elsif ($arg eq "-rebuild")
 			{
-		shift @ARGV;
+			shift @args;
 			$rebuild = 1;
 			}
 		elsif ($arg eq "-verbose")
 			{
-		shift @ARGV;
+			shift @args;
 			$verbose = 1;
 			}
 		elsif ($arg eq "-force-rewrite")
 			{
-		shift @ARGV;
+			shift @args;
 			$force_rewrite = 1;
 			}
 		elsif ($arg eq "-hash_file")
 			{
-		shift @ARGV;
+			shift @args;
-		$hash_file = shift @ARGV;
+			$hash_file = shift @args;
 			}
 		elsif ($arg eq "-recurse")
 			{
-		shift @ARGV;
+			shift @args;
 			$recurse = 1;
 			}
 		elsif ($arg eq "-program_path")
 			{
-		shift @ARGV;
+			shift @args;
-		$check_program = shift @ARGV;
+			$check_program = shift @args;
 			}
 		else
 			{
-		die "Unknown Option $arg";
+			print STDERR "Unknown Option $arg";
+			return 1;
 			}
 
 		}
@@ -71,7 +87,11 @@ else
 
 	foreach $fp (@fingerprint_files)
 		{
-	open(IN, "$fp") || die "Can't open file $fp";
+		if (!open(IN, "$fp"))
+			{
+			print STDERR "Can't open file $fp";
+			return 1;
+			}
 		print STDERR "Opening Fingerprint file $fp\n" if $verbose;
 		my $dir = $fp;
 		$dir =~ s/[^\/]*$//;
@@ -83,22 +103,26 @@ foreach $fp (@fingerprint_files)
 				print STDERR "FATAL: Invalid syntax in file $fp\n";
 				print STDERR "Line:\n$_\n";
 				fatal_error();
+				return 1;
 				}
 			if (!$rebuild && length($hash) != 40)
 				{
 				print STDERR "FATAL: Invalid hash length in $fp for file $file\n";
 				fatal_error();
+				return 1;
 				}
 			push @hashed_files, "$dir$file";
 			if (exists $hashes{"$dir$file"})
 				{
 				print STDERR "FATAL: Duplicate Hash file $dir$file\n";
 				fatal_error();
+				return 1;
 				}
 			if (! -r "$dir$file")
 				{
 				print STDERR "FATAL: Can't access $dir$file\n";
 				fatal_error();
+				return 1;
 				}
 			$hashes{"$dir$file"} = $hash;
 			}
@@ -111,12 +135,14 @@ if ($? != 0)
 		{
 		print STDERR "Error running hash program $check_program\n";
 		fatal_error();
+		return 1;
 		}
 
 	if (@checked_hashes != @hashed_files)
 		{
 		print STDERR "FATAL: hash count incorrect\n";
 		fatal_error();
+		return 1;
 		}
 
 	foreach (@checked_hashes)
@@ -127,11 +153,13 @@ foreach (@checked_hashes)
 			print STDERR "FATAL: Invalid syntax in file $fp\n";
 			print STDERR "Line:\n$_\n";
 			fatal_error();
+			return 1;
 			}
 		if (length($hash) != 40)
 			{
 			print STDERR "FATAL: Invalid hash length for file $file\n";
 			fatal_error();
+			return 1;
 			}
 		if ($hash ne $hashes{$file})
 			{
@@ -155,12 +183,17 @@ if ($badfiles && !$rebuild)
 		{
 		print STDERR "FATAL: hash mismatch on $badfiles files\n";
 		fatal_error();
+		return 1;
 		}
 
 	if ($badfiles || $force_rewrite)
 		{
 		print "Updating Hash file $hash_file\n";
-	open OUT, ">$hash_file" || die "Error rewriting $hash_file";
+		if (!open(OUT, ">$hash_file"))
+			{
+			print STDERR "Error rewriting $hash_file";
+			return 1;
+			}
 		foreach (@hashed_files)
 			{
 			print OUT "HMAC-SHA1($_)= $hashes{$_}\n";
@@ -173,9 +206,12 @@ if (!$badfiles)
 		print "FIPS hash check successful\n";
 		}
 
+	}
+
 
 sub fatal_error
 	{
 	print STDERR "*** Your source code does not match the FIPS validated source ***\n";
-	exit 1;
 	}
+
+