[exim-cvs] Docs: tidy more uses of tainted variables

Gitweb: https://git.exim.org/exim.git/commitdiff/6e2400bf8b3c728f5bf8af52054fcab4e2351e21

Commit:     6e2400bf8b3c728f5bf8af52054fcab4e2351e21
Parent:     c1433919b200eebe16811dd27977c8a57fd2547e
Author:     Jeremy Harris <jgh146exb@???>
AuthorDate: Thu Jun 18 20:27:52 2020 +0100
Committer:  Jeremy Harris <jgh146exb@???>
CommitDate: Thu Jun 18 20:27:52 2020 +0100

    Docs: tidy more uses of tainted variables
---
 doc/doc-docbook/spec.xfpt | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index 874ef31..e29f133 100644
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -12472,7 +12472,8 @@ the complete argument of the ETRN command (see section &<<SECTETRN>>&).

.cindex "tainted data"
If the origin of the data is an incoming message,
-the result of expanding this variable is tainted.
+the result of expanding this variable is tainted and may not
+be further expanded or used as a filename.
When an untainted version is needed, one should be obtained from
looking up the value in a local (therefore trusted) database.
Often &$domain_data$& is usable in this role.
@@ -12672,7 +12673,8 @@ once.

.cindex "tainted data"
If the origin of the data is an incoming message,
-the result of expanding this variable is tainted.
+the result of expanding this variable is tainted and
+may not be further expanded or used as a filename.

&*Warning*&: the content of this variable is usually provided by a potential
attacker.
@@ -35474,14 +35476,14 @@ address if its delivery failed.


.section "Per-address filtering" "SECTperaddfil"
-.vindex "&$domain$&"
-.vindex "&$local_part$&"
+.vindex "&$domain_data$&"
+.vindex "&$local_part_data$&"
In contrast to the system filter, which is run just once per message for each
delivery attempt, it is also possible to set up a system-wide filtering
operation that runs once for each recipient address. In this case, variables
-such as &$local_part$& and &$domain$& can be used, and indeed, the choice of
-filter file could be made dependent on them. This is an example of a router
-which implements such a filter:
+such as &$local_part_data$& and &$domain_data$& can be used,
+and indeed, the choice of filter file could be made dependent on them.
+This is an example of a router which implements such a filter:
.code
central_filter:
check_local_user
@@ -37302,7 +37304,7 @@ follows:
.code
my_mailboxes:
driver = appendfile
- file = /var/mail/$domain/$local_part_data
+ file = /var/mail/$domain_data/$local_part_data
user = mail
.endd
This uses a directory of mailboxes for each domain. The &%user%& setting is
@@ -37342,7 +37344,7 @@ It runs a user's &_.forward_& file for all local parts of the form
cases by testing the variable &$local_part_suffix$&. For example:
.code
if $local_part_suffix contains -special then
-save /home/$local_part/Mail/special
+save /home/$local_part_data/Mail/special
endif
.endd
If the filter file does not exist, or does not deal with such addresses, they