AWS KMS支持使用ECDH。下面是一个使用Java SDK的示例代码：

import com.amazonaws.services.kms.AWSKMS;
import com.amazonaws.services.kms.AWSKMSClientBuilder;
import com.amazonaws.services.kms.model.DecryptRequest;
import com.amazonaws.services.kms.model.EncryptRequest;
import com.amazonaws.services.kms.model.GenerateDataKeyPairRequest;
import com.amazonaws.services.kms.model.GenerateDataKeyPairResult;
import com.amazonaws.util.Base64;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.security.InvalidAlgorithmParameterException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.spec.ECGenParameterSpec;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.KeySpec;

public class ECDHExample {

    public static void main(String[] args) throws NoSuchAlgorithmException, InvalidKeySpecException, InvalidAlgorithmParameterException {
        String keyId = "arn:aws:kms:us-west-2:123456789012:key/abcd1234-abcd-1234-abcd-1234abcd5678";

        AWSKMS client = AWSKMSClientBuilder.standard().withRegion("us-west-2").build();

        // Generate ECDH Key Pair using AWS KMS
        ECGenParameterSpec ecGenSpec = new ECGenParameterSpec("secp384r1");
        KeySpec keySpec = new ECGenParameterSpec("secp384r1");
        GenerateDataKeyPairRequest generateDataKeyPairRequest = new GenerateDataKeyPairRequest().withKeyId(keyId).withKeySpec(keySpec);
        GenerateDataKeyPairResult generateDataKeyPairResult = client.generateDataKeyPair(generateDataKeyPairRequest);
        byte[] publicKey = generateDataKeyPairResult.getPublicKey().array();
        byte[] privateKey = generateDataKeyPairResult.getPrivateKey().array();

        // Encrypt Data with ECDH Public Key
        SecureRandom random = new SecureRandom();
        byte[] data = "Hello World".getBytes();
        byte[] iv = new byte[16];
        random.nextBytes(iv);

        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        SecretKeySpec secretKeySpec = new SecretKeySpec(publicKey, "AES");
        cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec);
        byte[] encryptedData = cipher.doFinal(data);

        // Decrypt Data with ECDH Private Key
        DecryptRequest decryptRequest = new DecryptRequest().withCiphertextBlob(generateDataKeyPairResult.getCiphertextBlob()).withEncryptionAlgorithm("RSAES_OAEP_SHA_256");
        byte[] decryptedPrivateKey = client.decrypt(decryptRequest).getPlaintext().array();

        SecretKey secretKey = new SecretKeySpec(privateKey, "AES