1 files changed, 169 insertions, 0 deletions
diff --git a/bcprov/src/main/java/org/bouncycastle/math/ec/custom/sec/SecP521R1FieldElement.java b/bcprov/src/main/java/org/bouncycastle/math/ec/custom/sec/SecP521R1FieldElement.java
new file mode 100644
index 0000000..ce9b639
--- /dev/null
+++ b/bcprov/src/main/java/org/bouncycastle/math/ec/custom/sec/SecP521R1FieldElement.java
@@ -0,0 +1,169 @@
+package org.bouncycastle.math.ec.custom.sec;
+
+import java.math.BigInteger;
+
+import org.bouncycastle.math.ec.ECFieldElement;
+import org.bouncycastle.math.raw.Mod;
+import org.bouncycastle.math.raw.Nat;
+import org.bouncycastle.util.Arrays;
+
+public class SecP521R1FieldElement extends ECFieldElement
+{
+    public static final BigInteger Q = SecP521R1Curve.q;
+
+    protected int[] x;
+
+    public SecP521R1FieldElement(BigInteger x)
+    {
+        if (x == null || x.signum() < 0 || x.compareTo(Q) >= 0)
+        {
+            throw new IllegalArgumentException("x value invalid for SecP521R1FieldElement");
+        }
+
+        this.x = SecP521R1Field.fromBigInteger(x);
+    }
+
+    public SecP521R1FieldElement()
+    {
+        this.x = Nat.create(17);
+    }
+
+    protected SecP521R1FieldElement(int[] x)
+    {
+        this.x = x;
+    }
+
+    public boolean isZero()
+    {
+        return Nat.isZero(17, x);
+    }
+
+    public boolean isOne()
+    {
+        return Nat.isOne(17, x);
+    }
+
+    public boolean testBitZero()
+    {
+        return Nat.getBit(x, 0) == 1;
+    }
+
+    public BigInteger toBigInteger()
+    {
+        return Nat.toBigInteger(17, x);
+    }
+
+    public String getFieldName()
+    {
+        return "SecP521R1Field";
+    }
+
+    public int getFieldSize()
+    {
+        return Q.bitLength();
+    }
+
+    public ECFieldElement add(ECFieldElement b)
+    {
+        int[] z = Nat.create(17);
+        SecP521R1Field.add(x, ((SecP521R1FieldElement)b).x, z);
+        return new SecP521R1FieldElement(z);
+    }
+
+    public ECFieldElement addOne()
+    {
+        int[] z = Nat.create(17);
+        SecP521R1Field.addOne(x, z);
+        return new SecP521R1FieldElement(z);
+    }
+
+    public ECFieldElement subtract(ECFieldElement b)
+    {
+        int[] z = Nat.create(17);
+        SecP521R1Field.subtract(x, ((SecP521R1FieldElement)b).x, z);
+        return new SecP521R1FieldElement(z);
+    }
+
+    public ECFieldElement multiply(ECFieldElement b)
+    {
+        int[] z = Nat.create(17);
+        SecP521R1Field.multiply(x, ((SecP521R1FieldElement)b).x, z);
+        return new SecP521R1FieldElement(z);
+    }
+
+    public ECFieldElement divide(ECFieldElement b)
+    {
+//        return multiply(b.invert());
+        int[] z = Nat.create(17);
+        Mod.invert(SecP521R1Field.P, ((SecP521R1FieldElement)b).x, z);
+        SecP521R1Field.multiply(z, x, z);
+        return new SecP521R1FieldElement(z);
+    }
+
+    public ECFieldElement negate()
+    {
+        int[] z = Nat.create(17);
+        SecP521R1Field.negate(x, z);
+        return new SecP521R1FieldElement(z);
+    }
+
+    public ECFieldElement square()
+    {
+        int[] z = Nat.create(17);
+        SecP521R1Field.square(x, z);
+        return new SecP521R1FieldElement(z);
+    }
+
+    public ECFieldElement invert()
+    {
+//        return new SecP521R1FieldElement(toBigInteger().modInverse(Q));
+        int[] z = Nat.create(17);
+        Mod.invert(SecP521R1Field.P, x, z);
+        return new SecP521R1FieldElement(z);
+    }
+
+    // D.1.4 91
+    /**
+     * return a sqrt root - the routine verifies that the calculation returns the right value - if
+     * none exists it returns null.
+     */
+    public ECFieldElement sqrt()
+    {
+        // Raise this element to the exponent 2^519
+
+        int[] x1 = this.x;
+        if (Nat.isZero(17, x1) || Nat.isOne(17, x1))
+        {
+            return this;
+        }
+
+        int[] t1 = Nat.create(17);
+        int[] t2 = Nat.create(17);
+
+        SecP521R1Field.squareN(x1, 519, t1);
+        SecP521R1Field.square(t1, t2);
+
+        return Nat.eq(17, x1, t2) ? new SecP521R1FieldElement(t1) : null;
+    }
+
+    public boolean equals(Object other)
+    {
+        if (other == this)
+        {
+            return true;
+        }
+
+        if (!(other instanceof SecP521R1FieldElement))
+        {
+            return false;
+        }
+
+        SecP521R1FieldElement o = (SecP521R1FieldElement)other;
+        return Nat.eq(17, x, o.x);
+    }
+
+    public int hashCode()
+    {
+        return Q.hashCode() ^ Arrays.hashCode(x, 0, 17);
+    }
+}