Arcfour
class
class Arcfour {
var i;
var j;
Map S;
Arcfour() {
this.i = 0;
this.j = 0;
this.S = new Map();
}
// Initialize arcfour context from key, an array of ints, each from [0..255]
init(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;
}
next() {
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];
}
}
Constructors
new Arcfour() #
Arcfour() {
this.i = 0;
this.j = 0;
this.S = new Map();
}
Methods
init(key) #
init(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;
}
next() #
next() {
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];
}