Add keys generation code in SAES

iamrohitsuthar · Mar 16, 2021 · 0536b4d · 0536b4d
1 parent eaf17cd
commit 0536b4d
Showing 1 changed file with 54 additions and 2 deletions.
diff --git a/ICS/Assignment2/SAES.java b/ICS/Assignment2/SAES.java
@@ -5,6 +5,52 @@
 
 public class SAES {
 
+	private static final String[][] SBOX = { {"1001","0100","1010","1011"},{"1101","0001","1000","0101"},{"0110","0010","0000","0011"},{"1100","1110","1111","0111"} };
+	private static String key0 = null, key1 = null, key2 = null;
+
+	public SAES(String key) {
+		generateKeys(key);
+	}
+
+	private String rotateNibble(int word) {
+		String str = String.format("%8s", Integer.toBinaryString(word & 0xFF)).replace(' ', '0');
+		return str.substring(4,8) + str.substring(0,4);
+	}
+
+	private int binToDec(String binary) {
+		if(binary.equals("00")) return 0;
+		else if(binary.equals("01")) return 1;
+		else if(binary.equals("10")) return 2;
+		else return 3;
+	}
+
+	private String subNibble(String word) {
+		String s1 = word.substring(0,4);
+		String s2 = word.substring(4,8);
+		return SBOX[binToDec(s1.substring(0,2))][binToDec(s1.substring(2,4))] + SBOX[binToDec(s2.substring(0,2))][binToDec(s2.substring(2,4))];	
+	}
+
+	private void generateKeys(String key) {
+		int w0 = Integer.parseInt(key.substring(0,8),2);
+		int w1 = Integer.parseInt(key.substring(8,16),2);
+		int w2 = w0 ^ 0b10000000 ^ Integer.parseInt(subNibble(rotateNibble(w1)),2);
+		int w3 = w2 ^ w1;
+		int w4 = w2 ^ 0b00110000 ^ Integer.parseInt(subNibble(rotateNibble(w3)),2);
+		int w5 = w4 ^ w3;
+
+		key0 = String.format("%8s", Integer.toBinaryString(w0 & 0xFF)).replace(' ', '0') + String.format("%8s", Integer.toBinaryString(w1 & 0xFF)).replace(' ', '0');
+		key1 = String.format("%8s", Integer.toBinaryString(w2 & 0xFF)).replace(' ', '0') + String.format("%8s", Integer.toBinaryString(w3 & 0xFF)).replace(' ', '0');
+		key2 = String.format("%8s", Integer.toBinaryString(w4 & 0xFF)).replace(' ', '0') + String.format("%8s", Integer.toBinaryString(w5 & 0xFF)).replace(' ', '0');
+	}
+
+	private String getKeys() {
+		StringBuilder sb = new StringBuilder();
+		sb.append("Key0: "+key0 + "\n");
+		sb.append("Key1: "+key1 + "\n");
+		sb.append("Key2: "+key2 + "\n");
+		return sb.toString();
+	}
+
 	private int gfMul(int a, int b) {
         int product = 0; //the product of the multiplication
 
@@ -23,9 +69,15 @@ private int gfMul(int a, int b) {
         return product;
     }
 
+
+
+
 	public static void main(String[] args) {
-		SAES saes = new SAES();
-		System.out.println(saes.gfMul(3,3));
+		String key = "0100101011110101";
+		String msg = "1101011100101000";
+		SAES saes = new SAES(key);
+		System.out.println(saes.getKeys());
+		// System.out.println(saes.gfMul(3,3));
 	}
 }