adjusted comments and changed prime size to 1024

src/ch/fhnw/mada/bonus/FileEncryptor.java

@@ -5,13 +5,13 @@ import java.math.BigInteger;
 public class FileEncryptor {
 	
 	/**
-	 * 
+	 * Decrypts a file.
 	 * @param keyFile
-	 * 			file with cryption key-values stored
+	 * 			file path with private key
 	 * @param inputFile
 	 * 			file to be decrypted
 	 * @param outputFile
-	 * 			decyrpted content
+	 * 			Here the decrypted output will be generated
 	 */
  
 	public static void decryptFile(String keyFile, String inputFile, String outputFile) {
@@ -36,13 +36,13 @@ public class FileEncryptor {
 	}
 	
 	/**
-	 * 
+	 *  Encrypts a file.
 	 * @param keyFile
-	 * 			file with cryption key-values stored
+	 * 			file with public key
 	 * @param inputFile
 	 * 			file to be encrypted
 	 * @param outputFile
-	 * 			encrypted content
+	 * 			Here the encrypted output will be generated
 	 */
 
 	public static void encryptFile(String keyFile, String inputFile, String outputFile) {

src/ch/fhnw/mada/bonus/FileHandler.java

@@ -9,13 +9,13 @@ import java.math.BigInteger;
 public class FileHandler {
 	
 	/**
-	 * 
+	 * Creates a serialized string of a key pair
 	 * @param n 
 	 * 			the first number of the public or private key (n)
 	 * @param key
-	 * 			secret or private key
+	 * 			public or private key
 	 * @return
-	 * 			StringBuilder in the form of: '(n,key)'
+	 * 			String in the form of: '(n,key)'
 	 */
 	
     public static String serializeKeyPair(BigInteger n, BigInteger key) {
@@ -29,11 +29,12 @@ public class FileHandler {
     }
     
     /**
-     * 
+     * Deserializes a key file content.
      * @param filecontent
      * 			Key-Value to be de-serialized
      * @return
-     * 			Array consisting of n and the key
+     * 			Array[0] = n (modulus)
+     * 		    Array[1] = private or public key
      */
     
     public static BigInteger[] deserializeKeyPair(String filecontent) {
@@ -46,9 +47,9 @@ public class FileHandler {
     }
     
     /**
-     * 
+     * Serializes an array of bigintegers to a string.
      * @param numbers
-     * 			Array of content to be serialized
+     * 			Array of bigintegers to be serialized
      * @return
      * 			a String that separates every number with a comma ','
      */
@@ -68,11 +69,11 @@ public class FileHandler {
     }
     
     /**
-     * 
+     * Deserializes the string of bigintegers to a biginterger array
      * @param content
      * 			Content to be de-serialized
      * @return
-     * 			Array consisting of a number
+     * 			Array consisting of bigintegers
      */
     
     public static BigInteger[] deserializeEncryptedContent(String content) {
@@ -88,9 +89,9 @@ public class FileHandler {
     
     
     /**
-     * 
+     * Writes a string to a file.
      * @param path
-     * 			the directory of the file
+     * 			the file path
      * @param content
      * 			the serialized content
      * @return
@@ -121,9 +122,9 @@ public class FileHandler {
     }
     
     /**
-     * 
+     * Reads a string from a file
      * @param path
-     * 			directory of the file, that should be read
+     * 			Path of the file, that should be read
      * @return
      * 			the content of the file
      */
@@ -155,7 +156,7 @@ public class FileHandler {
     }
     
     /**
-     * 
+     * Checks if directory exists.
      * @param dirPath
      * 			directory to be checked
      * @return
@@ -168,7 +169,7 @@ public class FileHandler {
     }
     
     /**
-     * 
+     * Checks if file exists.
      * @param filePath
      * 			directory to file to be checked
      * @return

src/ch/fhnw/mada/bonus/RSAHandler.java

@@ -4,20 +4,28 @@ import java.math.BigInteger;
 import java.util.Random;
 
 public class RSAHandler {
-    static final int PRIME_BIT_LENGTH = 128;
+    static final int PRIME_BIT_LENGTH = 1024;
 
+    /**
+     * Returns phi of (p*q)=n
+     * @param p first prime of the prime factorisation of n
+     * @param q second prime of the prime factorisation of n
+     * @return returns the size of the set Z* (phi of n)
+     */
     public static BigInteger eulersTotientFunction(BigInteger p, BigInteger q) {
         return p.subtract(BigInteger.ONE).multiply(q.subtract(BigInteger.ONE)); // (p-1) * (q-1)
     }
 
     /**
-     *
+     * This is an implementation of the extended euclidean algorithm.
+     * This is primarily used to compute the gcd of a and b.
      * @param a
-     * 			public modulus n
+     * 			First number
      * @param b
-     * 			public key
+     * 			Second number
      * @return
-     * 			Array with p and q for the private key
+     * 			Array[0] = gcd of a and b
+     * 		    gcd(a,b) = Array[1]*a + Array[2]*b
      */
     public static BigInteger[] extendedEuclideanAlgorithm(BigInteger a, BigInteger b) {
         BigInteger[] out = new BigInteger[3];
@@ -57,9 +65,9 @@ public class RSAHandler {
     }
     
     /**
-     *
+     * Creats a prime with the the bit length PRIME_BIT_LENGTH
      * @return
-     * 			a random BigInteger
+     * 			a random BigInteger prime
      */
 
     public static BigInteger createPrime() {
@@ -68,7 +76,7 @@ public class RSAHandler {
     
 
     /**
-     *
+     * Here the magic of creating a rsa key pair happens.
      * @param directory
      * 			directory to store the sk.txt and pk.txt
      * @return
@@ -111,12 +119,13 @@ public class RSAHandler {
     }
 
     /**
+     * Here the en-/decryption takes place. (x^exp mod n)
      * @param x
-     *            the Number on which the action is perfomed on
+     *            the message number
      * @param n
-     *            the first number of the public or private key (n)
+     *            the modulus
      * @param exp
-     *            the second number of the public or private key (e or d)
+     *            the exponent
      * 
      * @return x ^ exp mod n
      */

src/ch/fhnw/mada/bonus/RSAHandlerTest.java

@@ -17,7 +17,7 @@ public class RSAHandlerTest {
         expected[1] = new BigInteger("8");
         expected[2] = new BigInteger("-13");
 
-        BigInteger[] result = RSAHandler.extendedEucleadeanAlgorithm(a, b);
+        BigInteger[] result = RSAHandler.extendedEuclideanAlgorithm(a, b);
 
         assertArrayEquals(expected, result);
     }
@@ -31,7 +31,7 @@ public class RSAHandlerTest {
         expected[1] = new BigInteger("40147");
         expected[2] = new BigInteger("-86215");
 
-        BigInteger[] result = RSAHandler.extendedEucleadeanAlgorithm(a, b);
+        BigInteger[] result = RSAHandler.extendedEuclideanAlgorithm(a, b);
 
         assertArrayEquals(expected, result);
     }
@@ -45,7 +45,7 @@ public class RSAHandlerTest {
         expected[1] = new BigInteger("193");
         expected[2] = new BigInteger("-5506");
 
-        BigInteger[] result = RSAHandler.extendedEucleadeanAlgorithm(a, b);
+        BigInteger[] result = RSAHandler.extendedEuclideanAlgorithm(a, b);
 
         assertArrayEquals(expected, result);
     }