Created an abstract class with an abstract builder method that AES + RSA Keyrings will extend from and I also moved the warnIfEncryptionContextIsPresent() method from S3Keyring to RawKeyring since the method really only targets AES + RSA keyrings which will extend this class

Author: Anirav Kareddy

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

@@ -0,0 +1,51 @@
+// Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+package software.amazon.encryption.s3.materials;
+
+import org.apache.commons.logging.LogFactory;
+import software.amazon.encryption.s3.S3EncryptionClient;
+
+public abstract class RawKeyring extends S3Keyring {
+  protected final MaterialsDescription _materialsDescription;
+  protected final boolean _reEncryptInstructionFile;
+
+  protected RawKeyring(Builder<?, ?> builder) {
+    super(builder);
+    _materialsDescription = builder._materialsDescription;
+    _reEncryptInstructionFile = builder._reEncryptInstructionFile;
+  }
+  public MaterialsDescription materialsDescription() {
+    return _materialsDescription;
+  }
+  public boolean reEncryptInstructionFile() {
+    return _reEncryptInstructionFile;
+  }
+  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> {
+
+    protected MaterialsDescription _materialsDescription;
+    protected boolean _reEncryptInstructionFile = false;
+
+    protected Builder() {
+      super();
+    }
+
+    public BuilderT materialsDescription(MaterialsDescription materialsDescription) {
+      _materialsDescription = materialsDescription;
+      return builder();
+    }
+
+    public BuilderT reEncryptInstructionFile(boolean reEncryptInstructionFile) {
+      _reEncryptInstructionFile = reEncryptInstructionFile;
+      return builder();
+    }
+  }
+}