Recommit

Author: Rishi

src/AES.java

@@ -1,5 +1,7 @@
-
-import java.io.*;
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.FileWriter;
+import java.io.IOException;
 
 /**
  * @author Patrick Lu
@@ -10,8 +12,7 @@ public class AES {
     /**
      * S-BOX table used for Key Expansion and Sub-Bytes.
      */
-
-    public static final String newline = System.getProperty("line.separator");
+    public static final String newline = System.getProperty("line.separator"); //The newline for whatever system you choose to run in.
     public static enum Mode { ECB,CBC };
     public static final int[][] sbox = {{0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76}, {0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0}, {0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15}, {0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75}, {0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84}, {0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf}, {0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8}, {0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2}, {0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73}, {0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb}, {0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79}, {0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08}, {0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a}, {0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e}, {0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf}, {0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16}};
     /**
@@ -62,7 +63,7 @@ public static enum Mode { ECB,CBC };
     static BufferedReader input;
     static Mode mode;
     static FileWriter out;
-    static int keyFileIndex = 1;
+    static int keyFileIndex = 1; //Index where the keyFile argument should be. Used to determines the index of other arguments.
 
     /**
      * Empty AES constructor.
@@ -91,11 +92,11 @@ public static void main(String args[]) throws IOException
         try 
         {
             int keysizecheck = 128; //User's intended key size.
-            if (!args[1].equals("-length")) //defaults to 128-bit
+            if (!args[1].equals("-length")) //No optional length argument given.
             {
-                if(!args[1].equals("-mode")) //No optional arguments given;
+                if(!args[1].equals("-mode")) //No optional mode given either;
                 {
-                    
+                    //Defaults to 128-bit key size and ECB.
                 }
                 else //Mode option was given;
                 {
@@ -116,7 +117,7 @@ public static void main(String args[]) throws IOException
             }
             keyreader = new BufferedReader(new FileReader(args[keyFileIndex]));
             key = keyreader.readLine();
-            if(key.length() *4 != keysizecheck)
+            if(key.length() *4 != keysizecheck) //Check to see if user's intended key size matches the size of key in file.
             {
                 throw new Exception("Error: Attemping to use a " + key.length() * 4 + "-bit key with AES-"+keysizecheck);
             }           
@@ -159,7 +160,7 @@ else if(iv.length() != 32)
                 }
             }
             while (line != null) {
-                if (aes.validline(line)) //If line is valid (i.e. contains valid hex characters, encrpyt. Otherwise, skip line. 
+                if (line.matches("[0-9A-F]+")) //If line is valid (i.e. contains valid hex characters, encrpyt. Otherwise, skip line. 
                 {
                     if (line.length() < 32) {
                         line = String.format("%032x",Integer.parseInt(line, 16));
@@ -268,23 +269,6 @@ private void deepCopy2DArray(int[][] destination, int[][] source)
         }
     }
 
-    /**
-     * Checks the validity of the input line.
-     * @param line  The line who's validity we check
-     * @return A boolean to determine validity
-     */
-    private boolean validline(String line)
-    {
-        for (int i = 0; i < line.length(); i++) {
-            int c = (int) line.charAt(i);
-            if ((c >= 48 && c <= 57) || (c >= 65 && c <= 70)) {
-            } else {
-                return false;
-            }
-        }
-        return true;
-    }
-
     /**
      * Pulls out the subkey from the key formed from the keySchedule method
      * @param km key formed from AES.keySchedule()