Bug #15835 Updated: Problem on function gmp_invert ()

ID: 15835 Updated by: jimw@php.net Reported By: sama@inf.ufsc.br -Status: Open +Status: Closed Bug Type: *Math Functions Operating System: Linux - Red Hat 7.2 PHP Version: 4.1.2 New Comment: This bug has been fixed in CVS. it was a minor (but obviously crippling) typo. instead of doing gmp_invert(a,b), it was doing gmp_invert(a,a). oops! Previous Comments: ------------------------------------------------------------------------ [2002-03-04 10:50:41] sama@inf.ufsc.br Yes, I'm sure. The "Euclidean Algorithm" computes the greatest common divisor but, the "Extended Euclidean Algorithm" give you the multiplicative inverse. The multiplicative inverse of 7 module 13 is 2 so, if I use gmp_invert(7,13) it should return 2. Ok ? ------------------------------------------------------------------------ [2002-03-04 09:12:30] sander@php.net Are you sure that the extended Euclidean Algorithm does the same as gmp_invert? The Euclidean Algorithm computes the greatest common divisor, gmp_invert doesn't seem to do that... Anyway, gmp_invert seems to be broken. I can't get it to return anything else than false. So I ask you again: can you give me some human understandable data that works or should work? ------------------------------------------------------------------------ [2002-03-04 07:30:06] sama@inf.ufsc.br gmp_invert() should return the multiplicative inverse (if exist) of a number, module something. It's the extended Euclidean algorithm. I wrote this code and I can give you. I think there is something wrong to gmp_invert. ------------------------------------------------------------------------ [2002-03-03 06:42:28] sander@php.net I can't get gmp_invert() return anything other than false, but that might be because I have no idea what gmp_invert() does :) Can you supply some (human understandable) data that does work? ------------------------------------------------------------------------ [2002-03-02 14:20:49] sama@inf.ufsc.br Example: $x = gmp_init("0x00d2d025ec7e1dbb6d778a52394c988594c57b47d7327a3e676d3a5ca7a5af87c4153c80994cf781f6a9d4a2f0e66d04baffb0059853a8937a895f6d17e76950e1"); // mod $y = gmp_init("6211846575289879599"); // value $w = gmp_invert($y,$x); The $w value should be : 6673516182899846998314488146047624198500176381239637064622226136275029334435034698239463153441869117173460635003602664197747901516108936488872273669129832 ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at http://bugs.php.net/15835 -- Edit this bug report at http://bugs.php.net/?id=15835&edit=1