1 files changed, 158 insertions, 0 deletions
diff --git a/core/src/main/java/org/spongycastle/pqc/math/linearalgebra/GFElement.java b/core/src/main/java/org/spongycastle/pqc/math/linearalgebra/GFElement.java
new file mode 100644
index 00000000..c33f1956
--- /dev/null
+++ b/core/src/main/java/org/spongycastle/pqc/math/linearalgebra/GFElement.java
@@ -0,0 +1,158 @@
+package org.spongycastle.pqc.math.linearalgebra;
+
+import java.math.BigInteger;
+
+
+/**
+ * This interface defines a finite field element. It is implemented by the
+ * classes {@link GFPElement} and {@link GF2nElement}.
+ *
+ * @see GFPElement
+ * @see GF2nElement
+ */
+public interface GFElement
+{
+
+    /**
+     * @return a copy of this GFElement
+     */
+    Object clone();
+
+    // /////////////////////////////////////////////////////////////////
+    // comparison
+    // /////////////////////////////////////////////////////////////////
+
+    /**
+     * Compare this curve with another object.
+     *
+     * @param other the other object
+     * @return the result of the comparison
+     */
+    boolean equals(Object other);
+
+    /**
+     * @return the hash code of this element
+     */
+    int hashCode();
+
+    /**
+     * Checks whether this element is zero.
+     *
+     * @return <tt>true</tt> if <tt>this</tt> is the zero element
+     */
+    boolean isZero();
+
+    /**
+     * Checks whether this element is one.
+     *
+     * @return <tt>true</tt> if <tt>this</tt> is the one element
+     */
+    boolean isOne();
+
+    // /////////////////////////////////////////////////////////////////////
+    // arithmetic
+    // /////////////////////////////////////////////////////////////////////
+
+    /**
+     * Compute the sum of this element and the addend.
+     *
+     * @param addend the addend
+     * @return <tt>this + other</tt> (newly created)
+     * @throws DifferentFieldsException if the elements are of different fields.
+     */
+    GFElement add(GFElement addend)
+        throws RuntimeException;
+
+    /**
+     * Compute the sum of this element and the addend, overwriting this element.
+     *
+     * @param addend the addend
+     * @throws DifferentFieldsException if the elements are of different fields.
+     */
+    void addToThis(GFElement addend)
+        throws RuntimeException;
+
+    /**
+     * Compute the difference of this element and <tt>minuend</tt>.
+     *
+     * @param minuend the minuend
+     * @return <tt>this - minuend</tt> (newly created)
+     * @throws DifferentFieldsException if the elements are of different fields.
+     */
+    GFElement subtract(GFElement minuend)
+        throws RuntimeException;
+
+    /**
+     * Compute the difference of this element and <tt>minuend</tt>,
+     * overwriting this element.
+     *
+     * @param minuend the minuend
+     * @throws DifferentFieldsException if the elements are of different fields.
+     */
+    void subtractFromThis(GFElement minuend);
+
+    /**
+     * Compute the product of this element and <tt>factor</tt>.
+     *
+     * @param factor the factor
+     * @return <tt>this * factor</tt> (newly created)
+     * @throws DifferentFieldsException if the elements are of different fields.
+     */
+    GFElement multiply(GFElement factor)
+        throws RuntimeException;
+
+    /**
+     * Compute <tt>this * factor</tt> (overwrite <tt>this</tt>).
+     *
+     * @param factor the factor
+     * @throws DifferentFieldsException if the elements are of different fields.
+     */
+    void multiplyThisBy(GFElement factor)
+        throws RuntimeException;
+
+    /**
+     * Compute the multiplicative inverse of this element.
+     *
+     * @return <tt>this<sup>-1</sup></tt> (newly created)
+     * @throws ArithmeticException if <tt>this</tt> is the zero element.
+     */
+    GFElement invert()
+        throws ArithmeticException;
+
+    // /////////////////////////////////////////////////////////////////////
+    // conversion
+    // /////////////////////////////////////////////////////////////////////
+
+    /**
+     * Returns this element as FlexiBigInt. The conversion is <a
+     * href="http://grouper.ieee.org/groups/1363/">P1363</a>-conform.
+     *
+     * @return this element as BigInt
+     */
+    BigInteger toFlexiBigInt();
+
+    /**
+     * Returns this element as byte array. The conversion is <a href =
+     * "http://grouper.ieee.org/groups/1363/">P1363</a>-conform.
+     *
+     * @return this element as byte array
+     */
+    byte[] toByteArray();
+
+    /**
+     * Return a String representation of this element.
+     *
+     * @return String representation of this element
+     */
+    String toString();
+
+    /**
+     * Return a String representation of this element. <tt>radix</tt>
+     * specifies the radix of the String representation.
+     *
+     * @param radix specifies the radix of the String representation
+     * @return String representation of this element with the specified radix
+     */
+    String toString(int radix);
+
+}