Fuck Casper.

pir/src/main/java/dk/alexandra/fresco/framework/builder/numeric/field/BigIntegerFieldElement.java

@@ -1,86 +0,0 @@
-package dk.alexandra.fresco.framework.builder.numeric.field;
-
-import dk.alexandra.fresco.framework.util.MathUtils;
-import java.math.BigInteger;
-
-/**
- * An element in a field defined by a {@link BigIntegerModulus}.
- */
-final public class BigIntegerFieldElement implements FieldElement {
-
-    private static final long serialVersionUID = -6786266947587799652L;
-
-    private final BigInteger value;
-
-    private final BigIntegerModulus modulus;
-    private BigIntegerFieldElement(BigInteger value, BigIntegerModulus modulus) {
-        this.value = modulus.reduceModThis(value);
-        this.modulus = modulus;
-    }
-
-    private FieldElement create(BigInteger value) {
-        return create(value, this.modulus);
-    }
-
-    static FieldElement create(BigInteger value, BigIntegerModulus modulus) {
-        return new BigIntegerFieldElement(value, modulus);
-    }
-
-    static FieldElement create(long value, BigIntegerModulus modulus) {
-        return create(BigInteger.valueOf(value), modulus);
-    }
-
-    static FieldElement create(String string, BigIntegerModulus modulus) {
-        return create(new BigInteger(string), modulus);
-    }
-
-    @Override
-    public FieldElement add(FieldElement operand) {
-        return create(value.add(extractValue(operand)));
-    }
-
-    @Override
-    public FieldElement subtract(FieldElement operand) {
-        return create(value.subtract(extractValue(operand)));
-    }
-
-    @Override
-    public FieldElement negate() {
-        return create(getModulus().subtract(value));
-    }
-
-    @Override
-    public FieldElement multiply(FieldElement operand) {
-        return create(value.multiply(extractValue(operand)));
-    }
-
-    @Override
-    public FieldElement sqrt() {
-        return create(MathUtils.modularSqrt(value, getModulus()));
-    }
-
-    @Override
-    public FieldElement modInverse() {
-        return create(value.modInverse(getModulus()));
-    }
-
-    static BigInteger extractValue(FieldElement element) {
-        return ((BigIntegerFieldElement) element).value;
-    }
-
-    public BigInteger getValue() {
-        return value;
-    }
-
-    private BigInteger getModulus() {
-        return modulus.getBigInteger();
-    }
-
-    @Override
-    public String toString() {
-        return "BigIntegerFieldElement{"
-                + "value=" + value
-                + ", modulus=" + modulus
-                + '}';
-    }
-}

pir/src/main/java/dk/au/pir/BigIntegerField.java

@@ -0,0 +1,38 @@
+package dk.au.pir;
+
+import java.math.BigInteger;
+import java.security.SecureRandom;
+
+public class BigIntegerField {
+
+    private final BigInteger groupOrder;
+    private final SecureRandom rand;
+
+    private static final BigInteger TWO = BigInteger.valueOf(2);
+    private static final BigInteger THREE = BigInteger.valueOf(3);
+
+    public BigIntegerField(){
+        this.groupOrder = new BigInteger("65519");
+        this.rand = new SecureRandom();
+    }
+
+    public BigInteger getElement(){
+        // TODO: Consider how to make random BigIntegers
+        byte bytes[] = new byte[20];
+        rand.nextBytes(bytes);
+        return new BigInteger(bytes).mod(groupOrder);
+    }
+
+    public BigInteger multiply(BigInteger elem1, BigInteger elem2){
+        return elem1.multiply(elem2).mod(groupOrder);
+    }
+
+    public BigInteger add(BigInteger elem1, BigInteger elem2){
+        return elem1.add(elem2).mod(groupOrder);
+    }
+
+    public BigInteger getGroupOrder(){
+        return groupOrder;
+    }
+
+}

pir/src/main/java/dk/au/pir/Driver.java

@@ -2,12 +2,31 @@ package dk.au.pir;
 
 import dk.alexandra.fresco.framework.builder.numeric.field.FieldElement;
 import dk.au.pir.protocols.interpoly.InterPolyClient;
+import dk.au.pir.protocols.interpoly.InterPolyServer;
+import dk.au.pir.settings.PIRSettings;
+
+import java.math.BigInteger;
+import java.util.ArrayList;
 
 public class Driver {
     public static void main(String[] args) {
-        InterPolyClient client = new InterPolyClient();
+        InterPolyClient client = new InterPolyClient(5);
-        for (FieldElement elem: client.getSRandomFieldElements()) {
+        InterPolyServer[] servers = new InterPolyServer[PIRSettings.MOD_BIT_LENGTH + 1];
-            System.out.println(elem);
+        
+        client.generateSRandomFieldElements();
+        // Perhaps randomize values
+
+        BigInteger[] results = new BigInteger[PIRSettings.MOD_BIT_LENGTH + 1];
+
+        int[] database = new int[PIRSettings.DATABASE_SIZE];
+        database[5] = 1;
+
+        for (int z = 0; z < PIRSettings.MOD_BIT_LENGTH+1; z++) {
+            servers[z] = new InterPolyServer(database);
+            servers[z].receiveGs(client.sendGs(z));
+            results[z] = servers[z].F();
         }
+        BigInteger res = client.receiveResults(results);
+        System.out.println(res);
     }
 }

pir/src/main/java/dk/au/pir/protocols/interpoly/InterPolyClient.java

@@ -1,35 +1,62 @@
 package dk.au.pir.protocols.interpoly;
 
-import dk.alexandra.fresco.framework.builder.numeric.field.BigIntegerFieldElement;
+import dk.au.pir.BigIntegerField;
-import dk.alexandra.fresco.framework.builder.numeric.field.FieldElement;
 import dk.au.pir.settings.PIRSettings;
+import dk.au.pir.utils.BigIntegerLagrangeInterpolation;
 
 import java.math.BigInteger;
+import java.util.ArrayList;
 import java.util.Random;
+import java.util.concurrent.ThreadLocalRandom;
 
 public class InterPolyClient {
+
     private final int i;
     private Random random = new Random();
-    private BigIntegerFieldElement[] fieldElements = new BigIntegerFieldElement[PIRSettings.MOD_BIT_LENGTH];
+    private BigIntegerField field;
+
+
+    private BigInteger[] fieldElements = new BigInteger[PIRSettings.MOD_BIT_LENGTH];
 
     public InterPolyClient(int i) {
         this.i = i;
+        this.field = new BigIntegerField();
     }
 
     public void generateSRandomFieldElements() {
         for (int i = 0; i < fieldElements.length; i++) {
-            this.fieldElements[i] = (BigIntegerFieldElement) PIRSettings.FIELD_DEFINITION.createElement(new BigInteger(PIRSettings.MAX_BIT_LENGTH, random));
+            this.fieldElements[i] = field.getElement();
         }
     }
 
-    public FieldElement g(int l, BigIntegerFieldElement z) {
+    public BigInteger g(int l, int z) {
         String iString = Integer.toBinaryString(i);
+        String pads = new String(new char[PIRSettings.MOD_BIT_LENGTH - iString.length()]).replace("\0", "0");
+        iString = pads + iString;
         char lChar = iString.charAt(iString.length() - 1 - l);  // lol
-        BigIntegerFieldElement il = (BigIntegerFieldElement) PIRSettings.FIELD_DEFINITION.createElement(Character.toString(lChar));
+        String ilString = Character.toString(lChar);
-        return fieldElements[l].multiply(z).add(il);
+        BigInteger il = new BigInteger(ilString).mod(field.getGroupOrder());
+        return field.add(field.multiply(fieldElements[l], (BigInteger.valueOf(z))), il);
     }
 
-    public FieldElement[] getFieldElements() {
+    public BigInteger[] sendGs(int z){
+        BigInteger[] gs = new BigInteger[PIRSettings.MOD_BIT_LENGTH];
+        for (int l = 0; l < PIRSettings.MOD_BIT_LENGTH; l++) {
+            gs[l] = g(l, z);
+        }
+        return gs;
+    }
+
+    public BigInteger[] getFieldElements() {
         return fieldElements;
     }
+
+
+    public BigInteger receiveResults(BigInteger[] results) {
+        BigInteger[] fuckingXs = new BigInteger[PIRSettings.MOD_BIT_LENGTH + 1];
+        for (int i = 0; i < PIRSettings.MOD_BIT_LENGTH + 1; i++) {
+            fuckingXs[i] = BigInteger.valueOf(i);
+        }
+       return BigIntegerLagrangeInterpolation.doIt(fuckingXs, results);
+    }
 }

pir/src/main/java/dk/au/pir/protocols/interpoly/InterPolyServer.java

@@ -1,5 +1,45 @@
 package dk.au.pir.protocols.interpoly;
 
+import dk.au.pir.settings.PIRSettings;
+
+import java.math.BigInteger;
+
 public class InterPolyServer {
 
+    private BigInteger[] gs;
+    private int[] database;
+
+    public InterPolyServer(int[] database) {
+        this.database = database;
+    }
+
+    public void receiveGs(BigInteger[] gs){
+        this.gs = gs;
+    }
+
+    public BigInteger f(int j){
+        BigInteger product = BigInteger.ONE;
+        for (int l = 0; l < PIRSettings.MOD_BIT_LENGTH; l++) {
+            String iString = Integer.toBinaryString(j);
+            String pads = new String(new char[PIRSettings.MOD_BIT_LENGTH - iString.length()]).replace("\0", "0");
+            iString = pads + iString;
+            char lChar = iString.charAt(iString.length() - 1 - l);  // lol
+            String jlString = Character.toString(lChar);
+
+            if (jlString.equals("1")){
+                product = product.multiply(gs[l]);
+            } else {
+                product = product.multiply(BigInteger.ONE.subtract(gs[l]));
+            }
+        }
+        return product;
+    }
+    public BigInteger F() {
+        BigInteger sum = BigInteger.ZERO;
+        for (int j = 0; j < PIRSettings.DATABASE_SIZE; j++) {
+            // Database consist of 0's or 1'
+            sum = sum.add(f(j).multiply(BigInteger.valueOf(database[j])));
+        }
+        return sum;
+    }
 }

pir/src/main/java/dk/au/pir/utils/BigIntegerLagrangeInterpolation.java

@@ -0,0 +1,24 @@
+package dk.au.pir.utils;
+
+import java.math.BigInteger;
+
+public class BigIntegerLagrangeInterpolation {
+    public static BigInteger doIt(BigInteger[] x, BigInteger[] y) {
+        // https://stackoverflow.com/questions/16375163/lagrange-interpolation-in-java
+        BigInteger xPoint = BigInteger.ZERO;  // we want to find f(0), so xpoint=0
+        BigInteger sum = BigInteger.ZERO;
+        BigInteger product = BigInteger.ONE;
+        for (int i = 0; i < x.length; i++) {
+            for (int j = 0; j < x.length; j++) {
+                if (j != i) {
+                    BigInteger a = xPoint.subtract(x[j]);
+                    BigInteger b = x[i].subtract(x[j]);
+                    product = product.multiply(a.divide(b));
+                }
+            }
+            sum = sum.add(product.multiply(y[i]));
+            product = BigInteger.ONE;
+        }
+        return sum;
+    }
+}