RE: UTL_RAW and slowness

Ah, I see. The business folks are happy that whoever wrote the previous bit has successfully 'encrypted' their data, and your job is to make that bit perform.

A familiar refrain. ;)

Jared

On Fri, 2003-10-24 at 06:34, Jamadagni, Rajendra wrote:
> Jared, I know, but this is a legacy code that is attached to a hardware ticker tape that scrolls message that it received. The code I supplied has couple of other operations removed (for obvious reasons) but these steps are required because the hardware chip in the ticker box won't recognize it.
>
> BTW, I have successfully used RC4 from your site in past to implement encryption.
>
> HTH Some
> Raj
>
> -----Original Message-----
> Sent: Thursday, October 23, 2003 7:06 PM
> To: ORACLE-L_at_fatcity.com
> Cc: Jamadagni, Rajendra
> Importance: High
>
>
>
> Raj,
>
> I'll try to be tactful here, but that isn't encryption. It only looks like
> encryption, and is in fact very easy to break.
>
> Check out the article at http://www.cybcon.com/~jkstill/util/encryption/encryption.html
>
> There are PL/SQL implementations of RC4 and Blowfish there. RC4 is a stream cipher
> and Blowfish is a block cipher. Either would suit your purpose.
>
> Blowfish is there courtesy of Craig Munday.
>
> RC4 is there courtesy of a leak at RSA, but it's in the public domain now, so that
> doesn't matter anymore.
>
> Also check Pete Finnigans site: http://www.petefinnigan.com/
>
> HTH
>
> Jared
>
>
>
>
>
> "Jamadagni, Rajendra" <Rajendra.Jamadagni_at_espn.com>
> Sent by: ml-errors_at_fatcity.com
>
>
> 10/23/2003 02:54 PM
> Please respond to ORACLE-L
>
>
>
> To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
> cc:
> Subject: UTL_RAW and slowness
>
>
>
> Hi all,
>
> I am experimenting with a block of pl/sql code (wrote myself) that uses utl_raw to perform xor operation. (Note to Jared and Mladan, I can't use Perl on production boxes, so don't even go there).
>
>
> I take a message, encrypt 1 character send it out on a wire using utl_tcp. After every 128 bytes, I flush the tcp connection. While this works fine and within our acceptable range for smallish messages (up to 20-25K in size), it nearly kills itself when working with larger messages (80k+).
>
>
> Initially I could encrypt 128 characters (including conversion from/to utl_raw) in about 50ms. Bt this increase progressively. When I reach about 98000 to 99000 range, it takes about 16 seconds to encrypt 128 characters.
>
>
> I have logged tar with Oracle, but does anyone know if one could do a block encryption (can't use standard algorithms, this is custom) like encrypt 128 characters at a time instead of 1 ...
>
>
> The skeleton code looks like this ...
>
>
> msglen := LENGTH (msg_text);
> nCharsSent := 0;
> p('Encrypting data...');
> FOR i IN 1 .. msglen
> LOOP
> ntcpchar := ASCII (SUBSTR (msg_text, i, 1));
> r_chr := utl_raw.cast_to_raw(CHR(ntcpchar));
> nenctcpchar := TO_NUMBER(utl_raw.bit_xor(r_chr,r_key),'xxxx');
> tcpmsglen := UTL_TCP.write_text (gv_tcp_conn, CHR(nenctcpchar), NULL);
> nCharsSent := nCharssent + 1;
> IF MOD(ncharssent,128) = 0 THEN
> p('Before Flush ...');
> UTL_TCP.FLUSH (gv_tcp_conn);
> p('Connection Flushed at ' || ncharssent);
> END IF;
> --
> END LOOP; -- FOR i IN 1 .. msglen
>
>
> where p is a procedure that dumps supplied text to a trace file with a timestamp that is up to 1 ms resolution. BTW this is a 9202 box. Also when it starts getting slow, using "nmon" I can see that this process is hogging a CUP at 99-100%. Of course this is a dev box, but my SA will not like this on a production box.
>
>
> Any ideas?
> Thanks in advance
> Raj
> --------------------------------------------------------------------------------
> Rajendra dot Jamadagni at nospamespn dot com
> All Views expressed in this email are strictly personal.
> QOTD: Any clod can have facts, having an opinion is an art !
>
>
>
>
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Author: Jared Still
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