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Cleaned up the Vigenere cipher operations so that they conform with the coding conventions.

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n1474335 2016-12-08 00:34:41 +00:00
parent e5854b6f86
commit 55c1626d41
7 changed files with 95 additions and 100 deletions
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121
src/js/operations/Cipher.js
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@ -387,101 +387,94 @@ var Cipher = {
/**
* @constant
* @default
*/
VIG_ENC_KEY: "cipher",
/**
* Vigenere cipher encode.
* Vigenère Encode operation.
*
* @author Matt C [matt@artemisbot.pw]
* @param {string} input
* @param {Object[]} args
* @returns {string}
*/
run_vigenc: function (input, args) {
run_vigenere_enc: function (input, args) {
var alphabet = "abcdefghijklmnopqrstuvwxyz",
keyword = args[0].toLowerCase(),
key = args[0].toLowerCase(),
output = "",
fail = 0,
keyIndex,
msgIndex,
key_index,
msg_index,
chr;
if (keyword) {
if (/^[a-zA-Z]+$/.test(keyword)) {
for (var i = 0; i < input.length; i++) {
if (alphabet.indexOf(input[i]) >= 0) {
chr = keyword[(i - fail) % keyword.length]; //Gets the corresponding character of keyword for current letter, accounting for chars not in alphabet
keyIndex = alphabet.indexOf(chr); //Gets location in vigenere square of keyword char
msgIndex = alphabet.indexOf(input[i]); //Gets location in vigenere square of message char
output += alphabet[(keyIndex + msgIndex) % 26]; //Gets encoded letter by finding sum of indexes modulo 26 and finding the letter corresponding to that
} else if (alphabet.indexOf(input[i].toLowerCase()) >= 0) {
chr = keyword[(i - fail) % keyword.length].toLowerCase();
keyIndex = alphabet.indexOf(chr);
msgIndex = alphabet.indexOf(input[i].toLowerCase());
output += alphabet[(keyIndex + msgIndex) % 26].toUpperCase();
} else {
output += input[i];
fail++;
}
}
if (!key) return "No key entered";
if (!/^[a-zA-Z]+$/.test(key)) return "The key must consist only of letters";
for (var i = 0; i < input.length; i++) {
if (alphabet.indexOf(input[i]) >= 0) {
// Get the corresponding character of key for the current letter, accounting
// for chars not in alphabet
chr = key[(i - fail) % key.length];
// Get the location in the vigenere square of the key char
key_index = alphabet.indexOf(chr);
// Get the location in the vigenere square of the message char
msg_index = alphabet.indexOf(input[i]);
// Get the encoded letter by finding the sum of indexes modulo 26 and finding
// the letter corresponding to that
output += alphabet[(key_index + msg_index) % 26];
} else if (alphabet.indexOf(input[i].toLowerCase()) >= 0) {
chr = key[(i - fail) % key.length].toLowerCase();
key_index = alphabet.indexOf(chr);
msg_index = alphabet.indexOf(input[i].toLowerCase());
output += alphabet[(key_index + msg_index) % 26].toUpperCase();
} else {
throw "Keyword can only consist of letters.";
output += input[i];
fail++;
}
} else {
throw "A keyword is required.";
}
return output;
},
/**
* @constant
* @default
*/
VIG_DEC_KEY: "cipher",
/**
* Vigenere cipher decode.
* Vigenère Decode operation.
*
* @author Matt C [matt@artemisbot.pw]
* @param {string} input
* @param {Object[]} args
* @returns {string}
*/
run_vigdec: function (input, args) {
run_vigenere_dec: function (input, args) {
var alphabet = "abcdefghijklmnopqrstuvwxyz",
keyword = args[0].toLowerCase(),
key = args[0].toLowerCase(),
output = "",
fail = 0,
keyIndex,
msgIndex,
key_index,
msg_index,
chr;
if (keyword) {
if (/^[a-zA-Z]+$/.test(keyword)) {
for (var i = 0; i < input.length; i++) {
if (alphabet.indexOf(input[i]) >= 0) {
chr = keyword[(i - fail) % keyword.length];
keyIndex = alphabet.indexOf(chr);
msgIndex = alphabet.indexOf(input[i]);
output += alphabet[(msgIndex - keyIndex + alphabet.length ) % 26]; //subtract indexes from each other, add 26 just in case the value is negative, modulo to remove if neccessary
} else if (alphabet.indexOf(input[i].toLowerCase()) >= 0) {
chr = keyword[(i - fail) % keyword.length].toLowerCase();
keyIndex = alphabet.indexOf(chr);
msgIndex = alphabet.indexOf(input[i].toLowerCase());
output += alphabet[(msgIndex + alphabet.length - keyIndex) % 26].toUpperCase();
} else {
output += input[i];
fail++;
}
}
if (!key) return "No key entered";
if (!/^[a-zA-Z]+$/.test(key)) return "The key must consist only of letters";
for (var i = 0; i < input.length; i++) {
if (alphabet.indexOf(input[i]) >= 0) {
chr = key[(i - fail) % key.length];
key_index = alphabet.indexOf(chr);
msg_index = alphabet.indexOf(input[i]);
// Subtract indexes from each other, add 26 just in case the value is negative,
// modulo to remove if neccessary
output += alphabet[(msg_index - key_index + alphabet.length ) % 26];
} else if (alphabet.indexOf(input[i].toLowerCase()) >= 0) {
chr = key[(i - fail) % key.length].toLowerCase();
key_index = alphabet.indexOf(chr);
msg_index = alphabet.indexOf(input[i].toLowerCase());
output += alphabet[(msg_index + alphabet.length - key_index) % 26].toUpperCase();
} else {
throw "Keyword can only consist of letters.";
output += input[i];
fail++;
}
} else {
throw "A keyword is required.";
}
return output;
}
},
};