20 Feb
2006
20 Feb
'06
11:55 a.m.
Hello Klaus,
On 02/20/06 12:31, Klaus Darilion wrote:
Daniel-Constantin Mierla wrote:
I am not sure I got what you want to achieve with this statement. Do you
want to forbid messages which have quotes or some other "dangerous"
characters in some pseudo-variables? Or you want to escape the quotes?
You can do quoting and escaping from the script, as you already
mentioned, using avp_subst(). Checks for special characters like quotes
or double dash can be done via avp_check().
Cheers,
Daniel
Hello Klaus,
On 02/17/06 14:59, Klaus Darilion wrote:
AFAIK there are 2 ways to prevent SQL injection.
1. quoting and escaping
2. Do not provide the user input in the SQL query, but explicit as
parameter. This way, the DB client library prevents SQL injection.
I've checked the postgresql module, which supports both version. If
"params" are defined, the safe version is used. But, when raw queries
are used, there is no protection through the API, thus, checks must
done before. Does this query work?
if (avp_subst("s:foo","/\"//")) {
sl_send_reply("403","bad syntax");
} Is the query SQL-injection save?
Depending
of what you do and how :-). Authenticating the user should
prevent bad values in From header and credentials, some character
sequences are not allowed to be part of user or domain names. Using
values from custom headers is quite risky, you have to use other
technics to ensure a trusted value. So, I am sure that someone can
get some examples of doing sql-injections even without using
avp_db_query() , there are many other modules doing SQL queries using
parts of SIP message, but these situations can be avoided if you know
what you are doing in the script. I do not know a technique to
prevent 100% SQL-injections, are you aware of?
regards
klaus