Merge "Cherrypick BigIntegers code from BouncyCastle v1.62."android-o-mr1-iot-release-1.0.14

1 files changed, 16 insertions, 0 deletions

diff --git a/repackaged/bcprov/src/main/java/com/android/org/bouncycastle/util/BigIntegers.java b/repackaged/bcprov/src/main/java/com/android/org/bouncycastle/util/BigIntegers.java
index fe7dbb8c..93e1a779 100644
--- a/repackaged/bcprov/src/main/java/com/android/org/bouncycastle/util/BigIntegers.java
+++ b/repackaged/bcprov/src/main/java/com/android/org/bouncycastle/util/BigIntegers.java
@@ -143,6 +143,15 @@ public final class BigIntegers
         return new BigInteger(1, createRandom(bitLength, random));
     }
 
+    // Hexadecimal value of the product of the 131 smallest odd primes from 3 to 743
+    private static final BigInteger SMALL_PRIMES_PRODUCT = new BigInteger(
+              "8138e8a0fcf3a4e84a771d40fd305d7f4aa59306d7251de54d98af8fe95729a1f"
+            + "73d893fa424cd2edc8636a6c3285e022b0e3866a565ae8108eed8591cd4fe8d2"
+            + "ce86165a978d719ebf647f362d33fca29cd179fb42401cbaf3df0c614056f9c8"
+            + "f3cfd51e474afb6bc6974f78db8aba8e9e517fded658591ab7502bd41849462f",
+        16);
+    private static final int SQR_MAX_SMALL = 20; // bitlength of 743 * 743
+
     /**
      * Return a prime number candidate of the specified bit length.
      *
@@ -176,6 +185,13 @@ public final class BigIntegers
             base[base.length - 1] |= 0x01;
 
             rv = new BigInteger(1, base);
+            if (bitLength > SQR_MAX_SMALL)
+            {
+                while (!rv.gcd(SMALL_PRIMES_PRODUCT).equals(ONE))
+                {
+                    rv = rv.add(TWO);
+                }
+            }
         }
         while (!rv.isProbablePrime(certainty));