refinement on GCD sieve, added bounds test

bcgit · Apr 4, 2019 · a34ea0e · a34ea0e
1 parent 522f6de
commit a34ea0e
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Showing 3 changed files with 38 additions and 3 deletions.
diff --git a/core/src/main/java/org/bouncycastle/util/BigIntegers.java b/core/src/main/java/org/bouncycastle/util/BigIntegers.java
@@ -148,7 +148,7 @@ public static BigInteger createRandomBigInteger(int bitLength, SecureRandom rand
             + "ce86165a978d719ebf647f362d33fca29cd179fb42401cbaf3df0c614056f9c8"
             + "f3cfd51e474afb6bc6974f78db8aba8e9e517fded658591ab7502bd41849462f",
         16);
-    private static final int SQR_MAX_SMALL = 20; // bitlength of 743 * 743
+    private static final int MAX_SMALL = BigInteger.valueOf(743).bitLength(); // bitlength of 743 * 743
 
     /**
      * Return a prime number candidate of the specified bit length.
@@ -183,7 +183,7 @@ public static BigInteger createRandomPrime(int bitLength, int certainty, SecureR
             base[base.length - 1] |= 0x01;
 
             rv = new BigInteger(1, base);
-            if (bitLength > SQR_MAX_SMALL)
+            if (bitLength > MAX_SMALL)
             {
                 while (!rv.gcd(SMALL_PRIMES_PRODUCT).equals(ONE))
                 {

diff --git a/core/src/test/java/org/bouncycastle/crypto/test/BigIntegersTest.java b/core/src/test/java/org/bouncycastle/crypto/test/BigIntegersTest.java
@@ -0,0 +1,34 @@
+package org.bouncycastle.crypto.test;
+
+import java.math.BigInteger;
+
+import org.bouncycastle.util.BigIntegers;
+import org.bouncycastle.util.test.SimpleTest;
+import org.bouncycastle.util.test.TestRandomData;
+
+public class BigIntegersTest
+    extends SimpleTest
+{
+    public String getName()
+    {
+        return "BigIntegers";
+    }
+
+    public void performTest()
+        throws Exception
+    {
+        BigInteger min = BigInteger.valueOf(5);
+        isTrue(min.equals(BigIntegers.createRandomPrime(min.bitLength(), 1,
+            new TestRandomData(BigIntegers.asUnsignedByteArray(min)))));
+
+        BigInteger max = BigInteger.valueOf(743);
+        isTrue(max.equals(BigIntegers.createRandomPrime(max.bitLength(), 1,
+            new TestRandomData(BigIntegers.asUnsignedByteArray(max)))));
+    }
+
+    public static void main(String[] args)
+        throws Exception
+    {
+        runTest(new BigIntegersTest());
+    }
+}
diff --git a/core/src/test/java/org/bouncycastle/crypto/test/RegressionTest.java b/core/src/test/java/org/bouncycastle/crypto/test/RegressionTest.java
@@ -166,7 +166,8 @@ public class RegressionTest
             new CSHAKETest(),
             new Argon2Test(),
             new OpenSSHKeyParsingTests(),
-            new EthereumIESTest()
+            new EthereumIESTest(),
+            new BigIntegersTest()
         };
 
     public static void main(