Changeset 18342 for gsdl

Timestamp:

2009-01-09T18:16:31+13:00 (15 years ago)

Author:

ak19

Message:

Added some base64 related methods (moved the call to MIME::base64 previously made in util.pm to here). The wrapper base64_encode method now helps to prevent re-encoding filenames using base64 several times over which was a little troubling before.

File:

• gsdl/trunk/perllib/unicode.pm (modified) (2 diffs)

gsdl/trunk/perllib/unicode.pm

@@ -36 +36 @@
 use strict;
 use util;
+use MIME::Base64; # for base64 encoding
 
 no strict 'refs';
@@ -629 +630 @@
 }
 
+sub base64_encode {
+    my ($text) = @_;
+    if(!is_safe_filename_chars($text)) {  #if(!&is_base64_or_alphanumeric($text)) { # a subset
+    $text = &MIME::Base64::encode_base64($text);
+    }
+    return $text;
+}
+
+sub base64_decode {
+    my ($text) = @_;
+    # If the input fits the base64 pattern, this will try decoding it.
+    # Still, this does not guarantee the return value is the 'original'
+    if(&is_base64_or_alphanumeric($text)) {
+    $text = &MIME::Base64::decode_base64($text);
+    }
+    return $text;
+}
+
+# Returns through if the given string is compatible with base64 (which 
+# includes regular ASCII alphanumeric values). This method does not 
+# guarantee that base64_decoding will return anything meanigful, since 
+# this will return true for any simple alphanumeric ASCII string as well.
+sub is_base64_or_alphanumeric {
+    my ($text) = @_;
+    # base 64 takes alphanumeric and [+/=] 
+    # (note that in some cases - and _ replace + and /)
+    return ($text =~ m/^[A-Za-z0-9\+\/\=]+$/);
+}
+
+# Returns true if the text is base64 chars or additionally contains - and/or _
+sub is_safe_filename_chars {
+    my ($text) = @_;
+    return ($text =~ m/^[A-Za-z0-9\+\/\=\-\_]+$/); #alphanumeric,[+/=-_]
+}
 
 sub substr