RT2272: Add old-style hash to c_rehash

In addition to Matthias's change, I also added -n to
not remove links. And updated the manpage.
Reviewed-by: NTim Hudson <tjh@openssl.org>

doc/apps/c_rehash.pod

@@ -10,6 +10,10 @@ c_rehash - Create symbolic links to files named by the hash values
 =head1 SYNOPSIS
 
 B<c_rehash>
+B<[-old]>
+B<[-h]>
+B<[-n]>
+B<[-v]>
 [ I<directory>...]
 
 =head1 DESCRIPTION
@@ -18,6 +22,7 @@ B<c_rehash> scans directories and calculates a hash value of each
 C<.pem>, C<.crt>, C<.cer>, or C<.crl>
 file in the specified directory list and creates symbolic links
 for each file, where the name of the link is the hash value.
+(If the platform does not support symbolic links, a copy is made.)
 This utility is useful as many programs that use OpenSSL require
 directories to be set up like this in order to find certificates.
 
@@ -35,6 +40,7 @@ is a hexadecimal character and B<D> is a single decimal digit.
 When processing a directory, B<c_rehash> will first remove all links
 that have a name in that syntax. If you have links in that format
 used for other purposes, they will be removed.
+To skip the removal step, use the B<-n> flag.
 Hashes for CRL's look similar except the letter B<r> appears after
 the period, like this: C<HHHHHHHH.rD>.
 
@@ -52,13 +58,39 @@ B<OPENSSL> environment variable to the full pathname.
 Any program can be used, it will be invoked as follows for either
 a certificate or CRL:
 
-  $OPENSSL x509 -hash -fingerprint -noout -in FFFFFF
-  $OPENSSL crl -hash -fingerprint -noout -in FFFFFF
+  $OPENSSL x509 -hash -fingerprint -noout -in FILENAME
+  $OPENSSL crl -hash -fingerprint -noout -in FILENAME
 
-where B<FFFFFF> is the filename. It must output the hash of the
+where B<FILENAME> is the filename. It must output the hash of the
 file on the first line, and the fingerprint on the second,
 optionally prefixed with some text and an equals sign.
 
+=head1 OPTIONS
+
+=over 4
+
+=item B<-old>
+
+Use old-style hashing (MD5, as opposed to SHA-1) for generating
+links for releases before 1.0.0.  Note that current versions will
+not use the old style.
+
+=item B<-h>
+
+Display a brief usage message.
+
+=item B<-n>
+
+Do not remove existing links.
+This is needed when keeping new and old-style links in the same directory.
+
+=item B<-v>
+
+Print messages about old links removed and new links created.
+By default, B<c_rehash> only lists each directory as it is processed.
+
+=back
+
 =head1 ENVIRONMENT
 
 =over

tools/c_rehash.in

 #!/usr/local/bin/perl
 
-
 # Perl c_rehash script, scan all files in a directory
 # and add symbolic links to their hash values.
 
-my $openssl;
-
 my $dir;
 my $prefix;
 
-if(defined $ENV{OPENSSL}) {
-	$openssl = $ENV{OPENSSL};
-} else {
-	$openssl = "openssl";
-	$ENV{OPENSSL} = $openssl;
+my $openssl = $ENV{OPENSSL} || "openssl";
+my $pwd;
+my $x509hash = "-subject_hash";
+my $crlhash = "-hash";
+my $verbose = 0;
+my $symlink_exists=eval {symlink("",""); 1};
+my $removelinks = 1;
+
+##  Parse flags.
+while ( $ARGV[0] =~ '-.*' ) {
+    my $flag = shift @ARGV;
+    last if ( $flag eq '--');
+    if ( $flag =~ /-old/) {
+	    $x509hash = "-subject_hash_old";
+	    $crlhash = "-hash_old";
+    } elsif ( $flag =~ /-h/) {
+	    help();
+    } elsif ( $flag eq '-n' ) {
+	    $removelinks = 0;
+    } elsif ( $flag eq '-v' ) {
+	    $verbose++;
+    }
+    else {
+	    print STDERR "Usage error; try -help.\n";
+	    exit 1;
+    }
+}
+
+sub help {
+	print "Usage: c_rehash [-old] [-h] [-v] [dirs...]\n";
+	print "   -old use old-style digest\n";
+	print "   -h print this help text\n";
+	print "   -v print files removed and linked\n";
+	exit 0;
 }
 
-my $pwd;
 eval "require Cwd";
 if (defined(&Cwd::getcwd)) {
 	$pwd=Cwd::getcwd();
 } else {
-	$pwd=`pwd`; chomp($pwd);
+	$pwd=`pwd`;
+	chomp($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
+# DOS/Win32 or Unix delimiter?  Prefix our installdir, then search.
+my $path_delim = ($pwd =~ /^[a-z]\:/i) ? ';' : ':';
+$ENV{PATH} = "$prefix/bin" . ($ENV{PATH} ? $path_delim . $ENV{PATH} : "");
 
 if(! -x $openssl) {
 	my $found = 0;
@@ -66,16 +93,19 @@ sub hash_dir {
 	my %hashlist;
 	print "Doing $_[0]\n";
 	chdir $_[0];
+	if ( $removelinks ) {
 		opendir(DIR, ".");
 		my @flist = readdir(DIR);
+		closedir DIR;
 		# Delete any existing symbolic links
 		foreach (grep {/^[\da-f]+\.r{0,1}\d+$/} @flist) {
 			if(-l $_) {
 				unlink $_;
+				print "unlink $_" if $verbose;
 			}
 		}
-	closedir DIR;
-	FILE: foreach $fname (grep {/\.(pem|crt|cer|crl)$/} @flist) {
+	}
+	FILE: foreach $fname (grep {/\.(pem)|(crt)|(cer)|(crl)$/} @flist) {
 		# Check to see if certificates and/or CRLs present.
 		my ($cert, $crl) = check_file($fname);
 		if(!$cert && !$crl) {
@@ -117,7 +147,7 @@ sub check_file {
 sub link_hash_cert {
 		my $fname = $_[0];
 		$fname =~ s/'/'\\''/g;
-		my ($hash, $fprint) = `"$openssl" x509 -hash -fingerprint -noout -in "$fname"`;
+		my ($hash, $fprint) = `"$openssl" x509 $x509hash -fingerprint -noout -in "$fname"`;
 		chomp $hash;
 		chomp $fprint;
 		$fprint =~ s/^.*=//;
@@ -133,16 +163,16 @@ sub link_hash_cert {
 			$suffix++;
 		}
 		$hash .= ".$suffix";
-		print "$fname => $hash\n";
-		$symlink_exists=eval {symlink("",""); 1};
 		if ($symlink_exists) {
 			symlink $fname, $hash;
+			print "link $fname -> $hash\n" if $verbose;
 		} else {
 			open IN,"<$fname" or die "can't open $fname for read";
 			open OUT,">$hash" or die "can't open $hash for write";
 			print OUT <IN>;	# does the job for small text files
 			close OUT;
 			close IN;
+			print "copy $fname -> $hash\n" if $verbose;
 		}
 		$hashlist{$hash} = $fprint;
 }
@@ -152,7 +182,7 @@ sub link_hash_cert {
 sub link_hash_crl {
 		my $fname = $_[0];
 		$fname =~ s/'/'\\''/g;
-		my ($hash, $fprint) = `"$openssl" crl -hash -fingerprint -noout -in '$fname'`;
+		my ($hash, $fprint) = `"$openssl" crl $crlhash -fingerprint -noout -in '$fname'`;
 		chomp $hash;
 		chomp $fprint;
 		$fprint =~ s/^.*=//;
@@ -168,12 +198,12 @@ sub link_hash_crl {
 			$suffix++;
 		}
 		$hash .= ".r$suffix";
-		print "$fname => $hash\n";
-		$symlink_exists=eval {symlink("",""); 1};
 		if ($symlink_exists) {
 			symlink $fname, $hash;
+			print "link $fname -> $hash\n" if $verbose;
 		} else {
 			system ("cp", $fname, $hash);
+			print "cp $fname -> $hash\n" if $verbose;
 		}
 		$hashlist{$hash} = $fprint;
 }