问JavaScript中的“密码破解”

EN

/**
 * Math Assignment Decoding w/o Equation
 * 
 * A simple decoder.
 * 
 * @author      RepeaterCreeper
 * @since       03/21/2018 18:08:00
 * @site        https://repeatercreeper.me
 */

var codes = [142, 92, 152, 102, 122, 62, 42, 107, 92, 152, 117, 22, 32, 92, 152, 27, 42, 77, 77, 157],
    tempA = [],
    tempB = [];

// Assigning of Letters to key
var letters = {
    1: 'A',
    2: 'B',
    3: 'C',
    4: 'D',
    5: 'E',
    6: 'F',
    7: 'G',
    8: 'H',
    9: 'I',
    10: 'J',
    11: 'K',
    12: 'L',
    13: 'M',
    14: 'N',
    15: 'O',
    16: 'P',
    17: 'Q',
    18: 'R',
    19: 'S',
    20: 'T',
    21: 'U',
    22: 'V',
    23: 'W',
    24: 'X',
    25: 'Y',
    26: 'Z',
    27: ' ',
    28: '!',
    29: '?',
    30: '@',
};

/**
 * All the equations are provided by the checkPossibleEquations function.
 * 
 * @param   {arrays}    equations       This parameter is a multidimensional array, contains pair of values.
 */
function bruteForce(equations) {
    var decodedMessage = "",
        currentEquation = 0;

    equations.forEach(function(data){
        decodedMessage += "(" + data[0] + ", " + data[1] +")[";
        for (var letterCode = 0; letterCode < codes.length; letterCode++) {
            for (var letter = 1; letter <= 30; letter++) {
                var solved = (data[0] * letter) + data[1];
                if (codes[letterCode] == solved) {
                    decodedMessage += letters[letter];
                }
            }
        }
        decodedMessage += "]";
        currentEquation += 1;
    });

    console.log(decodedMessage);
}


/**
 * Will check all possible equations, that works for AT LEAST two
 * values.
 * 
 * @return  array   Returns all equations that seem to work for TWO values.
 */
function checkPossibleEquations() {
    var possibleEquations = [];
    for (var i = 0; i < tempA.length; i++) {
        for (var j = 0; j < tempB.length; j++) {
            if (JSON.stringify(tempA[i]) == JSON.stringify(tempB[j])) {
                possibleEquations.push(tempA[i]);
            }
        }
    }

    return possibleEquations;
}

/**
 * Tries all possible combinations in the range of 1-50 and stores
 * in temporary array variable.
 * 
 * Equation: (i * letter) + k
 */
for (var i = 1; i <= 50; i++) {
    for (var k = 1; k <= 50; k++) {
        for (var letter = 0; letter < 30; letter++) {
            var encValPos = (i * letter) + k;
            // var encValNeg = i * letter - k;

            if (encValPos == codes[0]) {
                var temp = [];
                temp.push(i);
                temp.push(k);
                tempA.push(temp);
            }

            if (encValPos == codes[1]) {
                var temp2 = [];
                temp2.push(i);
                temp2.push(k);
                tempB.push(temp2);
            }
        }
    }
}

bruteForce(checkPossibleEquations());