如何创建GeneratePreSignedUrlRequest以下载加密文件

Question

我尝试使用服务器端加密来加密和解密文件。我正在使用Amazon Aws Sdk和Java。我想用客户提供的加密密钥进行服务器端加密。

我遵循本指南： http://docs.aws.amazon.com/AmazonS3/latest/dev/sse-c-using-java-sdk.html

我收到此错误：

The request signature we calculated does not match the signature you provided. Check your key and signing method

此操作有两种方法：encryptAndUpload()和decryptAndDownload()。

这是我的encryptAndUpload()方法。我使用的是签名版本4.我认为这种方法很好用。

    public void encryptAndUpload(byte[] salt, char[] password, InputStream stream, String key, String bucket){
       SecretKey secretKey = deriveKey(password, salt);
       SSECustomerKey sseCustomerKey = new SSECustomerKey(secretKey);

       ClientConfiguration clientConfiguration = new ClientConfiguration().withSignerOverride("AWSS3V4SignerType");
       AWSCredentials awsCredentials = new PropertiesCredentials(AmazonS3Uploader.class.getResourceAsStream("AwsCredentials.properties"));
       AmazonS3 amazonS3EncryptionClient = new AmazonS3Client(awsCredentials, clientConfiguration);
       amazonS3EncryptionClient.setRegion(Region.getRegion(Regions.EU_WEST_1));

       PutObjectRequest putObjectRequest = new PutObjectRequest(bucket, key, stream, new ObjectMetadata()).withSSECustomerKey(sseCustomerKey);
       PutObjectResult response = amazonS3EncryptionClient.putObject(putObjectRequest);
}

这是我的decryptAndDownload()方法。如您所见，创建键和amazonS3部件是完全相同的。

    public URL decryptAndDownload(byte[] salt, char[] password, String key, String bucket) throws InvalidKeySpecException, NoSuchAlgorithmException, IOException{
       SecretKey secretKey = deriveKey(password, salt);
       SSECustomerKey sseCustomerKey = new SSECustomerKey(secretKey);

       ClientConfiguration clientConfiguration = new ClientConfiguration().withSignerOverride("AWSS3V4SignerType");
       AWSCredentials awsCredentials = new PropertiesCredentials(AmazonS3Uploader.class.getResourceAsStream("AwsCredentials.properties"));
       AmazonS3 amazonS3EncryptionClient = new AmazonS3Client(awsCredentials, clientConfiguration);
       amazonS3EncryptionClient.setRegion(Region.getRegion(Regions.EU_WEST_1));

       GetObjectRequest getObjectRequest = new GetObjectRequest(bucket, key).withSSECustomerKey(sseCustomerKey);
       S3Object s3Object = amazonS3EncryptionClient.getObject(getObjectRequest);

       GeneratePresignedUrlRequest generatePresignedUrlRequest = new GeneratePresignedUrlRequest(s3Object.getBucketName(), s3Object.getKey(), HttpMethod.GET).withSSECustomerKey(sseCustomerKey);

       URL url = amazonS3EncryptionClient.generatePresignedUrl(generatePresignedUrlRequest);

       return url;
}

现在，我想创建generatePresignedUrlRequest是个问题。但我不知道如何解决它。我感谢任何帮助。我可以添加deriveKey方法，但我认为我的参数和deriveKey方法是正确的。

修改：为清晰起见，我添加了deriveKey方法：

    private SecretKey deriveKey(char[] password, byte[] salt) throws InvalidKeySpecException, NoSuchAlgorithmException {

       SecretKeyFactory secretKeyFactory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256");
       KeySpec keySpec = new PBEKeySpec(password, salt, 65536, 256);
       SecretKey tempSecretKey = secretKeyFactory.generateSecret(keySpec);
       SecretKey secretKey = new SecretKeySpec(tempSecretKey.getEncoded(), "AES");

       return secretKey;
}