Re: Prepared Statements

That's, then, even simpler that I originally thought. The only thing to
be done is to make using "real" prepared statements the default
behaviour of the PreparedStatement instances, is not it?

Fernando Nasser wrote:

> Peter Kovacs wrote:> I think that the simplest thing would be to have
> an option in the
>
>> backend to disable processing of multiple statements in one query --
>> i.e. disallow the use of ';' as a separator of statements. I am not
>> sure why this feature (multiple statments in one query) is there
>> anyway. "Reduce network roundtrips" is the usual reply, but, then,
>> what is the purpose of stored procedures (functions in PostgreSQL)?
>>
>
> I don't think the backend maintainers will like that. And btw we
> don't need this at all.
>
> 1) There is no risk of SQL injection with "real" (or "server side")
> prepared statements.
>
> 2) With the proper implementation of the client side prepared
> statements emulation the injected statements will not go through,
> because:
>
> a) all non-string results are properly quoted and generated from
> primary types.
>
> b) String type contents are quoted and have its quotes escaped.
>
>> In my perception, JDBC is meant to be a client side extension of the
>> server - bridge for Java clients to use the server (which in our case
>> is the right and honorable PostgreSQL). Prepared statements is a
>> mechanism to indicate the server that more query of this kind is
>> likely to come so the plan of the query should be kept ready to be
>> used again. That is what meant by PreparedStatement in the JDBC
>> driver. I find the concept of "client side prepared statements"
>> pretty weird.
>>
>
> It was added before the server had prepared statements so the
> applications could still use PreparedStatements and the getXXX and
> setXXX methods instead of recreating strings with queries all the
> time. Some of the applications run with other databases as well.
>
>> From this perspective, the whole wrestling with "drop table..." and
>> similar risks seem farily vain to me. At least, the driver is not the
>> place to solve this kind of security problems which basically exist
>> due to the wya the server behaves. Instead, the question should be
>> asked: is the behaviour of the server optimal?. Do we need this
>> feature (processing multiple, semi-colon separated statements)?
>> Should not this feature be eventually optional?
>>
>
> No SQL injection is possible with the backend implementation of
> prepared statements (with the V3 protocol, at least).
>
>
>