реализация атак грубой силы на хэш-значения в Javascript

Функция стиля грубой силы над алфавитом. Вероятно, есть более простые способы сделать это.

function brute(alphabet, match, int_start, int_stop){
    var a = alphabet, al = 0,                     // for alphabet
        m = match.toString(), ml = m.length,      // for our compare
        i = int_start || 0, j = int_stop || 0,    // range of numbers to test
        k = 0, l = 0, add = 0, sub = 0, diff = 0, // for building test string
        test = '', found = false;                 // test string and result

    if(i < 0) throw 'int_start must be at least 0';

    if(a.constructor !== undefined){           // We need a string or array as
        if( a.constructor.name !== 'String' && // our alphabet so we check for
            a.constructor.name !== 'Array' )   // correct input and modify if
                a = a.toString();              // necessary, or if we can't, 
    }
    else throw 'Bad alphabet type';            // we throw an error

    al = a.length;    // shorthand length

    add = al;                             // when i=0, we start prefix here
    while(add <= i - sub) sub += add,     // then work out what we have to
                          add = add * al; // prefix our number with

    diff = add - sub; // shorthand to save calculations

    while( i < j ){   // actual brute force loop starts here
        test = '';       // empty any previous string
        k = diff + i;    // convert our number from "x" to "1x"

        while(k > 0){           // build it as a string
            l = k % al;         // get index of digit
            test = a[l] + test; // add digit to string
            k = ( k - l ) / al; // move digits along
        }

        test = test.substring(1); // cut off the initial "1" we added

        if(test.length === ml && test === m){ // compare test to what you want
            found = true;
            break;
        }

        i++;                  // prepare for our next loop
        if(i - sub === add)   // and if we need another digit
            sub += add,       // then recalculate our prefix
            add = add * al,   // and then
            diff = add - sub; // update the shorthand 
    }

    // brute force ended, let's see what we've got

    if(found === false) i = -1; // if not found, return -1 as index

    return [i, test, m]; // index found, string found with, what we were looking for
}

Затем используйте через, например.

brute('0123abcd', '0c', 0, 20); // [14, "0c", "0c"]