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authorDominic Dunlop <domo@slipper.ip.lu>1996-12-28 10:56:41 +0100
committerChip Salzenberg <chip@atlantic.net>1997-01-01 08:59:00 +1200
commita034a98d8bfd0fd904012bd5227ce209aaaa0b26 (patch)
treee2afccfa1b455a13bf9d8e0ec521987c49b5c07c /pod/perlsec.pod
parente38874e2f3f61264e6d7b5d69540cdd51724e623 (diff)
downloadperl-a034a98d8bfd0fd904012bd5227ce209aaaa0b26.tar.gz
Locale-related pod patches, take 2
[Ahem. Had the wrong thing in the scratch-pad, didn't I? Please ignore my previous full posting of a slightly-tweaked perllocale.pod. This mail contains what I really meant to send.] Herewith (quick, before _18 appears) locale-related patches to the documentation in perl5.003_17/pod. The main effect is to add locale-related information to pods other than perllocale.pod, although there are some tiny tweaks to that pod too. Produces no complaints from pod2man; not checked for layout since 5.003_13. p5p-msgid: <v03007800aeea9e488b36@[194.51.248.77]>
Diffstat (limited to 'pod/perlsec.pod')
-rw-r--r--pod/perlsec.pod32
1 files changed, 20 insertions, 12 deletions
diff --git a/pod/perlsec.pod b/pod/perlsec.pod
index 2b6972701f..69de8592b6 100644
--- a/pod/perlsec.pod
+++ b/pod/perlsec.pod
@@ -30,14 +30,14 @@ program more secure than the corresponding C program.
You may not use data derived from outside your program to affect something
else outside your program--at least, not by accident. All command-line
-arguments, environment variables, and file input are marked as "tainted".
-Tainted data may not be used directly or indirectly in any command that
-invokes a sub-shell, nor in any command that modifies files, directories,
-or processes. Any variable set within an expression that has previously
-referenced a tainted value itself becomes tainted, even if it is logically
-impossible for the tainted value to influence the variable. Because
-taintedness is associated with each scalar value, some elements of an
-array can be tainted and others not.
+arguments, environment variables, locale information (see L<perllocale>),
+and file input are marked as "tainted". Tainted data may not be used
+directly or indirectly in any command that invokes a sub-shell, nor in any
+command that modifies files, directories, or processes. Any variable set
+within an expression that has previously referenced a tainted value itself
+becomes tainted, even if it is logically impossible for the tainted value
+to influence the variable. Because taintedness is associated with each
+scalar value, some elements of an array can be tainted and others not.
For example:
@@ -107,10 +107,10 @@ mechanism is by referencing sub-patterns from a regular expression match.
Perl presumes that if you reference a substring using $1, $2, etc., that
you knew what you were doing when you wrote the pattern. That means using
a bit of thought--don't just blindly untaint anything, or you defeat the
-entire mechanism. It's better to verify that the variable has only
-good characters (for certain values of "good") rather than checking
-whether it has any bad characters. That's because it's far too easy to
-miss bad characters that you never thought of.
+entire mechanism. It's better to verify that the variable has only good
+characters (for certain values of "good") rather than checking whether it
+has any bad characters. That's because it's far too easy to miss bad
+characters that you never thought of.
Here's a test to make sure that the data contains nothing but "word"
characters (alphabetics, numerics, and underscores), a hyphen, an at sign,
@@ -131,6 +131,14 @@ Laundering data using regular expression is the I<ONLY> mechanism for
untainting dirty data, unless you use the strategy detailed below to fork
a child of lesser privilege.
+The example does not untaint $data if C<use locale> is in effect,
+because the characters matched by C<\w> are determined by the locale.
+Perl considers that locale definitions are untrustworthy because they
+contain data from outside the program. If you are writing a
+locale-aware program, and want to launder data with a regular expression
+containing C<\w>, put C<no locale> ahead of the expression in the same
+block. See L<perllocale/SECURITY> for further discussion and examples.
+
=head2 Cleaning Up Your Path
For "Insecure C<$ENV{PATH}>" messages, you need to set C<$ENV{'PATH'}> to a