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"Drunk Bishop" RandomArt algorithm (from SSH), implemented as Javascript. Only demo code here, but can be trivially changed to give some return value to do something with the randomart.
<html>
<body>
<div id="renderDiv" style='font-family:"Lucida Console", Monaco, monospace' />
<script type="text/javascript">
// ENTER YOUR FINGERPRINT HERE
var fp = "d4:d3:fd:ca:c4:d3:e9:94:97:cc:52:21:3b:e4:ba:e9";
//Useful Functions
function checkHex(n){return/^[0-9A-Fa-f]{1,64}$/.test(n)}
function pad(s,z){s=""+s;return s.length<z?pad("0"+s,z):s}
//Hexadecimal Operations
function Hex2Bin(n){if(!checkHex(n))return 0;return parseInt(n,16).toString(2)}
function reverse(s) {
return s.split("").reverse().join("");
}
function isValidMove(x, y) {
return (0 <= x && x <= 16 && 0 <= y && y <= 8);
}
var map = [
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
];
var x = 8;
var y = 4;
var arr = fp.split(":"); // Split fingerprint into 8-bit words
for (var i = 0; i < 16; i++) { // Iterate through words
var bin = reverse(pad(Hex2Bin(arr[i]), 8)); // Convert to binary
for (var c = 0; c < 8; c = c + 2) { // Iterate through the bit-pairs in the words
var move = reverse(bin.substring(c, c + 2)); // determine the move
switch (move) {
case "00":
if (isValidMove(x - 1, y - 1)) {
x--;
y--;
} else if (isValidMove(x - 1, y)) {
x--;
} else if (isValidMove(x, y - 1)) {
y--;
}
break;
case "01":
if (isValidMove(x + 1, y - 1)) {
x++;
y--;
} else if (isValidMove(x + 1, y)) {
x++;
} else if (isValidMove(x, y - 1)) {
y--;
}
break;
case "10":
if (isValidMove(x - 1, y + 1)) {
x--;
y++;
} else if (isValidMove(x - 1, y)) {
x--;
} else if (isValidMove(x, y + 1)) {
y++;
}
break;
case "11":
if (isValidMove(x + 1, y + 1)) {
x++;
y++;
} else if (isValidMove(x + 1, y)) {
x++;
} else if (isValidMove(x, y + 1)) {
y++;
}
break;
default:
alert("WTF!");
}
map[y][x]++; // increment the value at the new position
}
}
map[y][x] = -1; // Set end position
map[4][8] = 255; // Re-set start position
// The following will render the visual fingerprint
var div = document.getElementById('renderDiv');
div.innerHTML = "+--[ RSA 2048]----+<br>";
for (var i = 0; i <= 8; i++) {
div.innerHTML = div.innerHTML + "|";
for (var j = 0; j <= 16; j++) {
var char = "&nbsp;";
switch (map[i][j]) {
case 1:
char = ".";
break;
case 2:
char = "o";
break;
case 3:
char = "+";
break;
case 4:
char = "=";
break;
case 5:
char = "*";
break;
case 6:
char = "B";
break;
case 7:
char = "O";
break;
case 8:
char = "X";
break;
case 9:
char = "@";
break;
case 10:
char = "%";
break;
case 11:
char = "&";
break;
case 12:
char = "#";
break;
case 13:
char = "/";
break;
case 14:
char = "^";
break;
case 255:
char = "S";
break;
case -1:
char = "E";
break;
default:
char = "&nbsp;";
}
div.innerHTML = div.innerHTML + char;
}
div.innerHTML = div.innerHTML + "|<br>";
}
div.innerHTML = div.innerHTML + "+-----------------+";
</script>
</body>
</html>
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