1 files changed, 21 insertions, 0 deletions
diff --git a/bcprov/src/main/java/org/bouncycastle/jcajce/provider/asymmetric/util/ECUtil.java b/bcprov/src/main/java/org/bouncycastle/jcajce/provider/asymmetric/util/ECUtil.java
index 06a93e5..b8ef398 100644
--- a/bcprov/src/main/java/org/bouncycastle/jcajce/provider/asymmetric/util/ECUtil.java
+++ b/bcprov/src/main/java/org/bouncycastle/jcajce/provider/asymmetric/util/ECUtil.java
@@ -1,5 +1,6 @@
 package org.bouncycastle.jcajce.provider.asymmetric.util;
 
+import java.math.BigInteger;
 import java.security.InvalidKeyException;
 import java.security.PrivateKey;
 import java.security.PublicKey;
@@ -16,6 +17,7 @@ import org.bouncycastle.asn1.sec.SECNamedCurves;
 // END android-removed
 import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo;
 import org.bouncycastle.asn1.x9.X962NamedCurves;
+import org.bouncycastle.asn1.x9.X962Parameters;
 import org.bouncycastle.asn1.x9.X9ECParameters;
 import org.bouncycastle.crypto.ec.CustomNamedCurves;
 import org.bouncycastle.crypto.params.AsymmetricKeyParameter;
@@ -218,6 +220,25 @@ public class ECUtil
         throw new InvalidKeyException("can't identify EC private key.");
     }
 
+    public static int getOrderBitLength(BigInteger order, BigInteger privateValue)
+    {
+        if (order == null)     // implicitly CA
+        {
+            ECParameterSpec implicitCA = BouncyCastleProvider.CONFIGURATION.getEcImplicitlyCa();
+
+            if (implicitCA == null)
+            {
+                return privateValue.bitLength();   // a guess but better than an exception!
+            }
+
+            return implicitCA.getN().bitLength();
+        }
+        else
+        {
+            return order.bitLength();
+        }
+    }
+
     public static ASN1ObjectIdentifier getNamedCurveOid(
         String name)
     {