added modifyMaterials() method to RawKeyring since common functionality between sub-classes AES + RSA Keyrings

Author: Anirav Kareddy

src/main/java/software/amazon/encryption/s3/materials/RawKeyring.java

@@ -20,13 +20,17 @@ public MaterialsDescription materialsDescription() {
   public boolean reEncryptInstructionFile() {
     return _reEncryptInstructionFile;
   }
+  public EncryptionMaterials modifyMaterials(EncryptionMaterials materials) {
+    warnIfEncryptionContextIsPresent(materials);
+
+    return materials;
+  }
   public void warnIfEncryptionContextIsPresent(EncryptionMaterials materials) {
     materials.s3Request().overrideConfiguration()
       .flatMap(overrideConfiguration ->
         overrideConfiguration.executionAttributes()
           .getOptionalAttribute(S3EncryptionClient.ENCRYPTION_CONTEXT))
       .ifPresent(ctx -> LogFactory.getLog(getClass()).warn("Usage of Encryption Context provides no security benefit in " + getClass().getSimpleName()));
-
   }
   public static abstract class Builder<KeyringT extends RawKeyring, BuilderT extends Builder<KeyringT, BuilderT>>
       extends S3Keyring.Builder<KeyringT, BuilderT> {