从S3读取加密数据

Question

我必须从S3存储桶下载数据，数据已加密，我有kms密钥来解密数据。代码在EC2实例中运行，EC2实例具有从S3读取的IAM角色。 我在此链接中看到了示例代码，但我无法读取内容。我收到以下异常

Exception in thread "main" com.amazonaws.SdkClientException: Unable to load credentials into profile [default]: AWS Access Key ID is not specified.
        at com.amazonaws.auth.profile.internal.ProfileStaticCredentialsProvider.fromStaticCredentials(ProfileStaticCredentialsProvider.java:55)
        at com.amazonaws.auth.profile.internal.ProfileStaticCredentialsProvider.<init>(ProfileStaticCredentialsProvider.java:40)
        at com.amazonaws.auth.profile.ProfilesConfigFile.fromProfile(ProfilesConfigFile.java:207)
        at com.amazonaws.auth.profile.ProfilesConfigFile.getCredentials(ProfilesConfigFile.java:160)

有人可以建议我出错的地方，或者提供一些如何在没有凭据的情况下从S3存储桶读取加密数据的指导

Answer 1

我通过提供InstanceProfileCredentialsProvider找到了解决方案.Below是代码。

 String kms_key = Constants.KMS_key;
        String inputString = null;
        KMSEncryptionMaterialsProvider materialProvider = new KMSEncryptionMaterialsProvider(kms_key);
        AmazonS3EncryptionClient client = new AmazonS3EncryptionClient(InstanceProfileCredentialsProvider.getInstance(),
                materialProvider);
        S3Object downloadedObject = client.getObject(bucketName, filePath);
        if (null != downloadedObject) {
            inputString = convertToString(downloadedObject.getObjectContent());
        }