1 files changed, 209 insertions, 0 deletions
diff --git a/src/share/classes/sun/security/util/math/intpoly/IntegerPolynomial1305.java b/src/share/classes/sun/security/util/math/intpoly/IntegerPolynomial1305.java
new file mode 100644
index 0000000000..794f44fb99
--- /dev/null
+++ b/src/share/classes/sun/security/util/math/intpoly/IntegerPolynomial1305.java
@@ -0,0 +1,209 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package sun.security.util.math.intpoly;
+
+import java.lang.invoke.MethodHandles;
+import java.math.BigInteger;
+import java.nio.*;
+
+/**
+ * An IntegerFieldModuloP designed for use with the Poly1305 authenticator.
+ * The representation uses 5 signed long values.
+ */
+
+public class IntegerPolynomial1305 extends IntegerPolynomial {
+
+    protected static final int SUBTRAHEND = 5;
+    protected static final int NUM_LIMBS = 5;
+    private static final int POWER = 130;
+    private static final int BITS_PER_LIMB = 26;
+    private static final BigInteger MODULUS
+        = TWO.pow(POWER).subtract(BigInteger.valueOf(SUBTRAHEND));
+
+    public IntegerPolynomial1305() {
+        super(BITS_PER_LIMB, NUM_LIMBS, 1, MODULUS);
+    }
+
+    protected void mult(long[] a, long[] b, long[] r) {
+
+        // Use grade-school multiplication into primitives to avoid the
+        // temporary array allocation. This is equivalent to the following
+        // code:
+        //  long[] c = new long[2 * NUM_LIMBS - 1];
+        //  for(int i = 0; i < NUM_LIMBS; i++) {
+        //      for(int j - 0; j < NUM_LIMBS; j++) {
+        //          c[i + j] += a[i] * b[j]
+        //      }
+        //  }
+
+        long c0 = (a[0] * b[0]);
+        long c1 = (a[0] * b[1]) + (a[1] * b[0]);
+        long c2 = (a[0] * b[2]) + (a[1] * b[1]) + (a[2] * b[0]);
+        long c3 = (a[0] * b[3]) + (a[1] * b[2]) + (a[2] * b[1]) + (a[3] * b[0]);
+        long c4 = (a[0] * b[4]) + (a[1] * b[3]) + (a[2] * b[2]) + (a[3] * b[1]) + (a[4] * b[0]);
+        long c5 = (a[1] * b[4]) + (a[2] * b[3]) + (a[3] * b[2]) + (a[4] * b[1]);
+        long c6 = (a[2] * b[4]) + (a[3] * b[3]) + (a[4] * b[2]);
+        long c7 = (a[3] * b[4]) + (a[4] * b[3]);
+        long c8 = (a[4] * b[4]);
+
+        carryReduce(r, c0, c1, c2, c3, c4, c5, c6, c7, c8);
+    }
+
+    private void carryReduce(long[] r, long c0, long c1, long c2, long c3,
+                             long c4, long c5, long c6, long c7, long c8) {
+        //reduce(2, 2)
+        r[2] = c2 + (c7 * SUBTRAHEND);
+        c3 += (c8 * SUBTRAHEND);
+
+        // carry(3, 2)
+        long carry3 = carryValue(c3);
+        r[3] = c3 - (carry3 << BITS_PER_LIMB);
+        c4 += carry3;
+
+        long carry4 = carryValue(c4);
+        r[4] = c4 - (carry4 << BITS_PER_LIMB);
+        c5 += carry4;
+
+        // reduce(0, 2)
+        r[0] = c0 + (c5 * SUBTRAHEND);
+        r[1] = c1 + (c6 * SUBTRAHEND);
+
+        // carry(0, 4)
+        carry(r);
+    }
+
+    @Override
+    protected void square(long[] a, long[] r) {
+        // Use grade-school multiplication with a simple squaring optimization.
+        // Multiply into primitives to avoid the temporary array allocation.
+        // This is equivalent to the following code:
+        //  long[] c = new long[2 * NUM_LIMBS - 1];
+        //  for(int i = 0; i < NUM_LIMBS; i++) {
+        //      c[2 * i] = a[i] * a[i];
+        //      for(int j = i + 1; j < NUM_LIMBS; j++) {
+        //          c[i + j] += 2 * a[i] * a[j]
+        //      }
+        //  }
+
+        long c0 = (a[0] * a[0]);
+        long c1 = 2 * (a[0] * a[1]);
+        long c2 = 2 * (a[0] * a[2]) + (a[1] * a[1]);
+        long c3 = 2 * (a[0] * a[3] + a[1] * a[2]);
+        long c4 = 2 * (a[0] * a[4] + a[1] * a[3]) + (a[2] * a[2]);
+        long c5 = 2 * (a[1] * a[4] + a[2] * a[3]);
+        long c6 = 2 * (a[2] * a[4]) + (a[3] * a[3]);
+        long c7 = 2 * (a[3] * a[4]);
+        long c8 = (a[4] * a[4]);
+
+        carryReduce(r, c0, c1, c2, c3, c4, c5, c6, c7, c8);
+    }
+
+    @Override
+    protected void encode(ByteBuffer buf, int length, byte highByte,
+                          long[] result) {
+        if (length == 16) {
+            long low = buf.getLong();
+            long high = buf.getLong();
+            encode(high, low, highByte, result);
+        } else {
+            super.encode(buf, length, highByte, result);
+        }
+    }
+
+    protected void encode(long high, long low, byte highByte, long[] result) {
+        result[0] = low & 0x3FFFFFFL;
+        result[1] = (low >>> 26) & 0x3FFFFFFL;
+        result[2] = (low >>> 52) + ((high & 0x3FFFL) << 12);
+        result[3] = (high >>> 14) & 0x3FFFFFFL;
+        result[4] = (high >>> 40) + (highByte << 24L);
+    }
+
+    protected void encode(byte[] v, int offset, int length, byte highByte,
+                          long[] result) {
+        if (length == 16) {
+            ByteBuffer asLongLEBuffer = ByteBuffer.wrap(v, offset, length)
+                    .order(ByteOrder.LITTLE_ENDIAN);
+            long low = asLongLEBuffer.getLong();
+            long high = asLongLEBuffer.getLong();
+            encode(high, low, highByte, result);
+        } else {
+            super.encode(v, offset, length, highByte, result);
+        }
+    }
+
+    private void modReduceIn(long[] limbs, int index, long x) {
+        // this only works when BITS_PER_LIMB * NUM_LIMBS = POWER exactly
+        long reducedValue = (x * SUBTRAHEND);
+        limbs[index - NUM_LIMBS] += reducedValue;
+    }
+
+    @Override
+    protected void finalCarryReduceLast(long[] limbs) {
+        long carry = limbs[numLimbs - 1] >> bitsPerLimb;
+        limbs[numLimbs - 1] -= carry << bitsPerLimb;
+        modReduceIn(limbs, numLimbs, carry);
+    }
+
+    protected final void modReduce(long[] limbs, int start, int end) {
+
+        for (int i = start; i < end; i++) {
+            modReduceIn(limbs, i, limbs[i]);
+            limbs[i] = 0;
+        }
+    }
+
+    protected void modReduce(long[] limbs) {
+
+        modReduce(limbs, NUM_LIMBS, NUM_LIMBS - 1);
+    }
+
+    @Override
+    protected long carryValue(long x) {
+        // This representation has plenty of extra space, so we can afford to
+        // do a simplified carry operation that is more time-efficient.
+
+        return x >> BITS_PER_LIMB;
+    }
+
+    @Override
+    protected void postEncodeCarry(long[] v) {
+        // not needed because carry is unsigned
+    }
+
+    @Override
+    protected void reduce(long[] limbs) {
+        long carry3 = carryOut(limbs, 3);
+        long new4 = carry3 + limbs[4];
+
+        long carry4 = carryValue(new4);
+        limbs[4] = new4 - (carry4 << BITS_PER_LIMB);
+
+        modReduceIn(limbs, 5, carry4);
+        carry(limbs);
+    }
+
+}
+