1 files changed, 90 insertions, 0 deletions
diff --git a/core/src/test/java/org/spongycastle/util/utiltest/BigIntegersTest.java b/core/src/test/java/org/spongycastle/util/utiltest/BigIntegersTest.java
new file mode 100644
index 00000000..f17745ee
--- /dev/null
+++ b/core/src/test/java/org/spongycastle/util/utiltest/BigIntegersTest.java
@@ -0,0 +1,90 @@
+package org.spongycastle.util.utiltest;
+
+import java.math.BigInteger;
+
+import junit.framework.Assert;
+import junit.framework.TestCase;
+import org.spongycastle.util.Arrays;
+import org.spongycastle.util.BigIntegers;
+import org.spongycastle.util.IPAddress;
+import org.spongycastle.util.encoders.Hex;
+
+public class BigIntegersTest
+    extends TestCase
+{
+    public String getName()
+    {
+        return "BigIntegers";
+    }
+
+    public void testAsUnsignedByteArray()
+    {
+        BigInteger a = new BigInteger(1, Hex.decode("ff12345678"));
+
+        byte[] a5 = BigIntegers.asUnsignedByteArray(a);
+
+        Assert.assertEquals(5, a5.length);
+        Assert.assertTrue(Arrays.areEqual(a5, Hex.decode("ff12345678")));
+
+        BigInteger b = new BigInteger(1, Hex.decode("0f12345678"));
+
+        byte[] b5 = BigIntegers.asUnsignedByteArray(b);
+
+        Assert.assertEquals(5, b5.length);
+        Assert.assertTrue(Arrays.areEqual(b5, Hex.decode("0f12345678")));
+    }
+
+    public void testFixedLengthUnsignedByteArray()
+    {
+        BigInteger a = new BigInteger(1, Hex.decode("ff12345678"));
+
+        byte[] a5 = BigIntegers.asUnsignedByteArray(5, a);
+
+        Assert.assertEquals(5, a5.length);
+        Assert.assertTrue(Arrays.areEqual(a5, Hex.decode("ff12345678")));
+
+        byte[] a6 = BigIntegers.asUnsignedByteArray(6, a);
+
+        Assert.assertEquals(6, a6.length);
+        Assert.assertEquals(0, a6[0]);
+        Assert.assertTrue(Arrays.areEqual(a6, Hex.decode("00ff12345678")));
+
+        BigInteger b = new BigInteger(1, Hex.decode("0f12345678"));
+
+        byte[] b5 = BigIntegers.asUnsignedByteArray(5, b);
+
+        Assert.assertEquals(5, b5.length);
+        Assert.assertTrue(Arrays.areEqual(b5, Hex.decode("0f12345678")));
+
+        byte[] b6 = BigIntegers.asUnsignedByteArray(6, b);
+
+        Assert.assertEquals(6, b6.length);
+        Assert.assertEquals(0, b6[0]);
+        Assert.assertTrue(Arrays.areEqual(b6, Hex.decode("000f12345678")));
+
+        BigInteger c = new BigInteger(1, Hex.decode("ff123456789a"));
+
+        try
+        {
+            byte[] c5 = BigIntegers.asUnsignedByteArray(5, c);
+
+            fail("no exception thrown");
+        }
+        catch (IllegalArgumentException e)
+        {
+            // ignore
+        }
+
+        BigInteger d = new BigInteger(1, Hex.decode("0f123456789a"));
+        try
+        {
+            byte[] c5 = BigIntegers.asUnsignedByteArray(5, d);
+
+            fail("no exception thrown");
+        }
+        catch (IllegalArgumentException e)
+        {
+            // ignore
+        }
+    }
+}