Util.pm: extend ldap_explode_dn() for RFC 4514

Extend ldap_explode_dn() to also parse DNs that conform to RFC 4514.

This way ldap_explode_dn() is rather lax in checking what it allows or not,
but tries to make sense of as much DNs as possible.

Changes:
  - only spaces ignored around attribute value instead of \s
  - NUL (U+0000) not allowed unquoted in attribute value
  - sharp/square/octothorpe (U+0023) allowed unquoted unless at first position
  - equal sign (U+003D) allowed unquoted in attribute value
  - space (U+0020) allowed to be quoted by \\ in a quoted pair

Test cases adapted accordingly.

lib/Net/LDAP/Util.pm

@@ -427,28 +427,32 @@ sub ldap_explode_dn($%) {
   return undef unless defined $dn;
   return [] if $dn eq '';
 
+  my $pair = qr/\\(?:[\\"+,;<> #=]|[0-9A-F]{2})/i;
+
   my (@dn, %rdn);
   while (
   $dn =~ /\G(?:
     \s*
-    ([a-zA-Z][-a-zA-Z0-9]*|(?:[Oo][Ii][Dd]\.)?\d+(?:\.\d+)*)
+    ((?i)[A-Z][-A-Z0-9]*|(?:oid\.)?\d+(?:\.\d+)*)	# attribute type
     \s*
     =
-    \s*
-    (
-      (?:[^\\",=+<>\#;]*[^\\",=+<>\#;\s]|\s*\\(?:[\\ ",=+<>#;]|[0-9a-fA-F]{2}))*
+    [ ]*
+    (							# attribute value
+      (?:(?:[^\x00 "\#+,;<>\\\x80-\xBF]|$pair)		# string
+         (?:(?:[^\x00"+,;<>\\]|$pair)*
+            (?:[^\x00 "+,;<>\\]|$pair))?)?
       |
-      \#(?:[0-9a-fA-F]{2})+
+      \#(?:[0-9a-fA-F]{2})+				# hex string
       |
-      "(?:[^\\"]+|\\(?:[\\",=+<>#;]|[0-9a-fA-F]{2}))*"
+      "(?:[^\\"]+|$pair)*"				# "-quoted string, only for v2
     )
-    \s*
-    (?:([;,+])\s*(?=\S)|$)
+    [ ]*
+    (?:([;,+])\s*(?=\S)|$)				# separator
     )\s*/gcx)
   {
     my($type,$val,$sep) = ($1,$2,$3);
 
-    $type =~ s/^oid\.(\d+(\.\d+)*)$/$1/i; #remove leading "oid."
+    $type =~ s/^oid\.//i;	#remove leading "oid."
 
     if ( !$opt{casefold} || $opt{casefold} eq 'upper' ) {
       $type = uc $type;

t/01canon_dn.t

@@ -69,7 +69,9 @@ same	OU = Sales+CN =J. Smith,O= Widget Inc.,C=US
 same	OU="Sales"+CN=J. Smith,O=Widget Inc.,C=US
 diff	OU="Sales+CN=J. Smith",O=Widget Inc.,C=US
 
-bad	cn=J.\20Smith\+ou=Sales,O=Widget\20Inc.,C=US
+ref	cn=J.\20Smith\+ou=Sales,O=Widget\20Inc.,C=US
+
+ref	cn=Clerk #1\+ou=Sales,O=Widget\20Inc.,C=US
 
 ref	CN=Babs Jensen,O=Widget Inc.,C=US
 same	cn=Babs Jensen,o=Widget Inc.,c=US