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ISAAC fast cryptographic random number generator
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// ================ | |
// ISAAC fast cryptographic random number generator | |
// ================ | |
// Author: McTwist | |
// Description: Generates cryptographic safe random numbers | |
// License: Free to use | |
// Source: http://www.burtleburtle.net/bob/rand/isaacafa.html | |
// ================ | |
// Init vars | |
$ISAAC::aa = 0; | |
$ISAAC::bb = 0; | |
$ISAAC::cc = 0; | |
$ISAAC::gnt = 0; | |
// Get a random cryptographic number | |
function randc() | |
{ | |
if (!$ISAAC::gnt--) | |
{ | |
isaac(); | |
$ISAAC::gnt = 255; | |
} | |
return $ISAAC::rands[$ISAAC::gnt]; | |
} | |
// Generate a new list of random numbers | |
function isaac() | |
{ | |
$ISAAC::cc = safe_add($ISAAC::cc, 1); | |
$ISAAC::bb = safe_add($ISAAC::bb, $ISAAC::cc); | |
for (%i = 0; %i < 256; %i++) | |
{ | |
%x = $ISAAC::mm[%i]; | |
switch (%i % 4) | |
{ | |
case 0: $ISAAC::aa ^= ($ISAAC::aa << 13); | |
case 1: $ISAAC::aa ^= ($ISAAC::aa >> 6); | |
case 2: $ISAAC::aa ^= ($ISAAC::aa << 2); | |
case 3: $ISAAC::aa ^= ($ISAAC::aa >> 16); | |
} | |
$ISAAC::aa = safe_add($ISAAC::mm[(%i + 128) % 256], $ISAAC::aa); | |
$ISAAC::mm[%i] = %y = safe_add($ISAAC::mm[(%x >> 2) % 256], safe_add($ISAAC::aa, $ISAAC::bb)); | |
$ISAAC::rands[%i] = $ISAAC::bb = safe_add($ISAAC::mm[(%y >> 10) % 256], %x); | |
} | |
} | |
// Initialize the randomizer | |
function isaac_init(%flag) | |
{ | |
$ISAAC::aa = $ISAAC::bb = $ISAAC::cc = 0; | |
%a = %b = %c = %d = %e = %f = %g = %h = 0x9e3779b9; | |
// Generate seed | |
if (%flag && $ISAAC::rands[0] $= "") | |
{ | |
for (%i = 0; %i < 256; %i++) | |
{ | |
$ISAAC::rands[%i] = getRandom(0, 0x7fffffff) | 0; | |
} | |
} | |
// Scrambled eggs | |
for (%i = 0; %i < 4; %i++) | |
{ | |
// Mix | |
%a ^= %b << 11; %d = safe_add(%d, %a); %b = safe_add(%b, %c); | |
%b ^= %c >> 2; %e = safe_add(%e, %b); %c = safe_add(%c, %d); | |
%c ^= %d << 8; %f = safe_add(%f, %c); %d = safe_add(%d, %e); | |
%d ^= %e >> 16; %g = safe_add(%g, %d); %e = safe_add(%e, %f); | |
%e ^= %f << 10; %h = safe_add(%h, %e); %f = safe_add(%f, %g); | |
%f ^= %g >> 4; %a = safe_add(%a, %f); %g = safe_add(%g, %h); | |
%g ^= %h << 8; %b = safe_add(%b, %g); %h = safe_add(%h, %a); | |
%h ^= %a >> 9; %c = safe_add(%c, %h); %a = safe_add(%a, %b); | |
} | |
// Fill in mm with messy stuff | |
for (%i = 0; %i < 256; %i++) | |
{ | |
if (%flag) | |
{ | |
%a = safe_add(%a, $ISAAC::rands[%i]); | |
%b = safe_add(%b, $ISAAC::rands[%i + 1]); | |
%c = safe_add(%c, $ISAAC::rands[%i + 2]); | |
%d = safe_add(%d, $ISAAC::rands[%i + 3]); | |
%e = safe_add(%e, $ISAAC::rands[%i + 4]); | |
%f = safe_add(%f, $ISAAC::rands[%i + 5]); | |
%g = safe_add(%g, $ISAAC::rands[%i + 6]); | |
%h = safe_add(%h, $ISAAC::rands[%i + 7]); | |
} | |
// Mix | |
%a ^= %b << 11; %d = safe_add(%d, %a); %b = safe_add(%b, %c); | |
%b ^= %c >> 2; %e = safe_add(%e, %b); %c = safe_add(%c, %d); | |
%c ^= %d << 8; %f = safe_add(%f, %c); %d = safe_add(%d, %e); | |
%d ^= %e >> 16; %g = safe_add(%g, %d); %e = safe_add(%e, %f); | |
%e ^= %f << 10; %h = safe_add(%h, %e); %f = safe_add(%f, %g); | |
%f ^= %g >> 4; %a = safe_add(%a, %f); %g = safe_add(%g, %h); | |
%g ^= %h << 8; %b = safe_add(%b, %g); %h = safe_add(%h, %a); | |
%h ^= %a >> 9; %c = safe_add(%c, %h); %a = safe_add(%a, %b); | |
$ISAAC::mm[%i] = %a; | |
$ISAAC::mm[%i + 1] = %b; | |
$ISAAC::mm[%i + 2] = %c; | |
$ISAAC::mm[%i + 3] = %d; | |
$ISAAC::mm[%i + 4] = %e; | |
$ISAAC::mm[%i + 5] = %f; | |
$ISAAC::mm[%i + 6] = %g; | |
$ISAAC::mm[%i + 7] = %h; | |
} | |
// An another round to make merry go round | |
if (%flag) | |
{ | |
for (%i = 0; %i < 256; %i++) | |
{ | |
%a = safe_add(%a, $ISAAC::mm[%i]); | |
%b = safe_add(%b, $ISAAC::mm[%i + 1]); | |
%c = safe_add(%c, $ISAAC::mm[%i + 2]); | |
%d = safe_add(%d, $ISAAC::mm[%i + 3]); | |
%e = safe_add(%e, $ISAAC::mm[%i + 4]); | |
%f = safe_add(%f, $ISAAC::mm[%i + 5]); | |
%g = safe_add(%g, $ISAAC::mm[%i + 6]); | |
%h = safe_add(%h, $ISAAC::mm[%i + 7]); | |
// Mix | |
%a ^= %b << 11; %d = safe_add(%d, %a); %b = safe_add(%b, %c); | |
%b ^= %c >> 2; %e = safe_add(%e, %b); %c = safe_add(%c, %d); | |
%c ^= %d << 8; %f = safe_add(%f, %c); %d = safe_add(%d, %e); | |
%d ^= %e >> 16; %g = safe_add(%g, %d); %e = safe_add(%e, %f); | |
%e ^= %f << 10; %h = safe_add(%h, %e); %f = safe_add(%f, %g); | |
%f ^= %g >> 4; %a = safe_add(%a, %f); %g = safe_add(%g, %h); | |
%g ^= %h << 8; %b = safe_add(%b, %g); %h = safe_add(%h, %a); | |
%h ^= %a >> 9; %c = safe_add(%c, %h); %a = safe_add(%a, %b); | |
$ISAAC::mm[%i] = %a; | |
$ISAAC::mm[%i + 1] = %b; | |
$ISAAC::mm[%i + 2] = %c; | |
$ISAAC::mm[%i + 3] = %d; | |
$ISAAC::mm[%i + 4] = %e; | |
$ISAAC::mm[%i + 5] = %f; | |
$ISAAC::mm[%i + 6] = %g; | |
$ISAAC::mm[%i + 7] = %h; | |
} | |
} | |
// Generate first batch | |
isaac(); | |
$ISAAC::gnt = 256; | |
} | |
// Safely add two values together like they are unsigned | |
// Algorithm: https://github.com/rubycon/isaac.js/blob/master/isaac.js#L106 | |
function safe_add(%a, %b) | |
{ | |
%lsb = (%a & 0xffff) + (%b & 0xffff); | |
%msb = (%a >> 16) + (%b >> 16) + (%lsb >> 16); | |
return (%msb << 16) | (%lsb & 0xffff); | |
} | |
// Initialize the first time | |
isaac_init(1); |
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