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Diffstat (limited to 'thirdparty/prng4.js')
-rw-r--r-- | thirdparty/prng4.js | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/thirdparty/prng4.js b/thirdparty/prng4.js new file mode 100644 index 0000000..4715372 --- /dev/null +++ b/thirdparty/prng4.js @@ -0,0 +1,79 @@ +// Downloaded from http://www-cs-students.stanford.edu/~tjw/jsbn/ by Jeremy White on 6/1/2012 + +/* + * Copyright (c) 2003-2005 Tom Wu + * All Rights Reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining + * a copy of this software and associated documentation files (the + * "Software"), to deal in the Software without restriction, including + * without limitation the rights to use, copy, modify, merge, publish, + * distribute, sublicense, and/or sell copies of the Software, and to + * permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, + * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY + * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. + * + * IN NO EVENT SHALL TOM WU BE LIABLE FOR ANY SPECIAL, INCIDENTAL, + * INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND, OR ANY DAMAGES WHATSOEVER + * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER OR NOT ADVISED OF + * THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF LIABILITY, ARISING OUT + * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + * + * In addition, the following condition applies: + * + * All redistributions must retain an intact copy of this copyright notice + * and disclaimer. + */ + + +// prng4.js - uses Arcfour as a PRNG + +function Arcfour() { + this.i = 0; + this.j = 0; + this.S = new Array(); +} + +// Initialize arcfour context from key, an array of ints, each from [0..255] +function ARC4init(key) { + var i, j, t; + for(i = 0; i < 256; ++i) + this.S[i] = i; + j = 0; + for(i = 0; i < 256; ++i) { + j = (j + this.S[i] + key[i % key.length]) & 255; + t = this.S[i]; + this.S[i] = this.S[j]; + this.S[j] = t; + } + this.i = 0; + this.j = 0; +} + +function ARC4next() { + var t; + this.i = (this.i + 1) & 255; + this.j = (this.j + this.S[this.i]) & 255; + t = this.S[this.i]; + this.S[this.i] = this.S[this.j]; + this.S[this.j] = t; + return this.S[(t + this.S[this.i]) & 255]; +} + +Arcfour.prototype.init = ARC4init; +Arcfour.prototype.next = ARC4next; + +// Plug in your RNG constructor here +function prng_newstate() { + return new Arcfour(); +} + +// Pool size must be a multiple of 4 and greater than 32. +// An array of bytes the size of the pool will be passed to init() +var rng_psize = 256; |