git-cvsserver: use a password file cvsserver pserver

If a git repository is shared via HTTP, the config file is typically
visible.  Use an external file instead.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-cvsserver.txt

@@ -100,16 +100,27 @@ looks like
 ------
 
 Only anonymous access is provided by pserve by default. To commit you
-will have to create pserver accounts, simply add a [gitcvs.users]
-section to the repositories you want to access, for example:
+will have to create pserver accounts, simply add a gitcvs.authdb
+setting in the config file of the repositories you want the cvsserver
+to allow writes to, for example:
 
 ------
 
-   [gitcvs.users]
-	someuser = somepassword
-	otheruser = otherpassword
+   [gitcvs]
+	authdb = /etc/cvsserver/passwd
+
+------
+The format of these files is username followed by the crypted password,
+for example:
 
 ------
+   myuser:$1Oyx5r9mdGZ2
+   myuser:$1$BA)@$vbnMJMDym7tA32AamXrm./
+------
+You can use the 'htpasswd' facility that comes with Apache to make these
+files, but Apache's MD5 crypt method differs from the one used by most C
+library's crypt() function, so don't use the -m option.
+
 Then provide your password via the pserver method, for example:
 ------
    cvs -d:pserver:someuser:somepassword <at> server/path/repo.git co <HEAD_name>

git-cvsserver.perl

@@ -189,24 +189,25 @@ if ($state->{method} eq 'pserver') {
 
     unless ($user eq 'anonymous') {
         # Trying to authenticate a user
-        if (not exists $cfg->{gitcvs}->{users}) {
-            print "E the repo config file needs a [gitcvs.users] section with user/password key-value pairs\n";
+        if (not exists $cfg->{gitcvs}->{authdb}) {
+            print "E the repo config file needs a [gitcvs.authdb] section with a filename\n";
             print "I HATE YOU\n";
             exit 1;
-        } elsif (exists $cfg->{gitcvs}->{users} and not exists $cfg->{gitcvs}->{users}->{$user}) {
-            #print "E the repo config file has a [gitcvs.users] section but the user $user is not defined in it\n";
+        }
+	my $auth_ok;
+	open PASSWD, "<$cfg->{gitcvs}->{authdb}" or die $!;
+	while(<PASSWD>) {
+	    if (m{^\Q$user\E:(.*)}) {
+		if (crypt($user, $1) eq $1) {
+		    $auth_ok = 1;
+		}
+	    };
+	}
+	unless ($auth_ok) {
             print "I HATE YOU\n";
             exit 1;
-        } else {
-            my $descrambled_password = descramble($password);
-            my $cleartext_password = $cfg->{gitcvs}->{users}->{$user};
-            if ($descrambled_password ne $cleartext_password) {
-                #print "E The password supplied for user $user was incorrect\n";
-                print "I HATE YOU\n";
-                exit 1;
-            }
-            # else fall through to LOVE
         }
+        # else fall through to LOVE
     }
 
     # For checking whether the user is anonymous on commit
@@ -337,7 +338,7 @@ sub req_Root
     }
     foreach my $line ( @gitvars )
     {
-        next unless ( $line =~ /^(gitcvs)\.(?:(ext|pserver|users)\.)?([\w-]+)=(.*)$/ );
+        next unless ( $line =~ /^(gitcvs)\.(?:(ext|pserver)\.)?([\w-]+)=(.*)$/ );
         unless ($2) {
             $cfg->{$1}{$3} = $4;
         } else {