private static Map<String, Parameters> namedParameters() throws GeneralSecurityException {
        Map<String, Parameters> result = new HashMap<>();

        result.put("AES128_CTR_HMAC_SHA256", PredefinedAeadParameters.AES128_CTR_HMAC_SHA256);
        result.put(
            "AES128_CTR_HMAC_SHA256_RAW",
            AesCtrHmacAeadParameters.builder()
                .setAesKeySizeBytes(16)
                .setHmacKeySizeBytes(32)
                .setTagSizeBytes(16)
                .setIvSizeBytes(16)
                .setHashType(AesCtrHmacAeadParameters.HashType.SHA256)
                .setVariant(AesCtrHmacAeadParameters.Variant.NO_PREFIX)
                .build());

        result.put("AES256_CTR_HMAC_SHA256", PredefinedAeadParameters.AES256_CTR_HMAC_SHA256);
        result.put(
            "AES256_CTR_HMAC_SHA256_RAW",
            AesCtrHmacAeadParameters.builder()
                .setAesKeySizeBytes(32)
                .setHmacKeySizeBytes(32)
                .setTagSizeBytes(32)
                .setIvSizeBytes(16)
                .setHashType(AesCtrHmacAeadParameters.HashType.SHA256)
                .setVariant(AesCtrHmacAeadParameters.Variant.NO_PREFIX)
                .build());

        return Collections.unmodifiableMap(result);
  }
This key manager generates new {@link AesCtrHmacAeadKey} keys and produces new instances of
{@link EncryptThenAuthenticate}.
java_src/src/main/java/com/google/crypto/tink/aead/AesCtrHmacAeadKeyManager.java