@Override
        protected Signature initialValue() {
            try {
                return Signature.getInstance("SHA256withRSA");
            } catch (NoSuchAlgorithmException e) {
                throw new SdkClientException("Could not create RSA Signature", e);
            }
        }
Utility for validating signatures on a Simple Notification Service JSON message.

@deprecated Use {@link SnsMessageManager} instead for both message unmarshalling and verification.
aws-java-sdk-sns/src/main/java/com/amazonaws/services/sns/util/SignatureChecker.java