Allow breaking Vigenere without brute force

Author: paul-ion

trainingportal/qna.js

@@ -79,9 +79,10 @@ let caesarEnc = (mes, key) => {
   return getRes(mes, shifted);
 }
 
-let vigenereEnc = (mes, key) => {
+let vigenereEnc = (m, key) => {
   let keyArray = [];
   let keyLen = 3;
+  let mes = "LOREM " + m;
 
   if(util.isNullOrUndefined(key)){
     for(let i = 0; i<keyLen; i++){

trainingportal/static/lessons/cryptoBreaker/definitions.json

@@ -16,7 +16,7 @@
                 "name":"Vigenère Cipher",
                 "description": "crypto_vigenere.md",
                 "type":"quiz",
-                "mission":"Decrypt the cipher below. As before, the plain text is in Latin.",
+                "mission":"Decrypt the cipher below knowing that the first word is 'LOREM'.",
                 "codeBlockIds":[]
             },
             {

trainingportal/test/qna.test.js

@@ -21,22 +21,14 @@ describe("qna", () => {
       let text = "PLAIN TEXT";
       for(let alg in qna.DEFS){
         if(alg === "crypto_analysis") continue;
-        let res = qna.getCode(alg,text);
+        let res = qna.getCode(alg,text);        
+        if(alg === "crypto_vigenere") text = "LOREM " + text;
         let check = qna.checkCode(text, res.digest);
         assert(check === true, `Validation failed for correct text using ${alg}`);
       }
     });
 
 
-    test("vigenere should return plain text for 'AAA'",()=>{
-      let text = "PLAIN TEXT";
-      let expected = "BYOUA HQKH"
-      let key = "MNO"
-      let res = qna.getCode("crypto_vigenere",text,key);
-      assert.strictEqual(res.code, expected, "Did not result in the same cipher for key: 'MNO'");
-
-    });
-
     test("xorOp should return plain text for '0x0'",()=>{
       let text = "PLAIN TEXT";
       let expected = "50 4C 41 49 4E 20 54 45 58 54";