/// <summary>
/// Updates the request where the metadata contains encryption information
/// and the input stream contains the encrypted object contents.
/// </summary>
/// <param name="putObjectRequest">
/// The request whose contents are to be encrypted.
/// </param>
private void GenerateEncryptedObjectRequestUsingMetadata(PutObjectRequest putObjectRequest)
{
// Create instruction
EncryptionInstructions instructions = EncryptionUtils.GenerateInstructions(this.encryptionMaterials);
EncryptionUtils.AddUnencryptedContentLengthToMetadata(putObjectRequest);
// Encrypt the object data with the instruction
putObjectRequest.InputStream = EncryptionUtils.EncryptRequestUsingInstruction(putObjectRequest.InputStream, instructions);
// Update the metadata
EncryptionUtils.UpdateMetadataWithEncryptionInstructions(putObjectRequest, instructions);
}
/// <summary>
/// Updates the request where the instruction file contains encryption information
/// and the input stream contains the encrypted object contents.
/// </summary>
/// <param name="putObjectRequest"></param>
private void GenerateEncryptedObjectRequestUsingInstructionFile(PutObjectRequest putObjectRequest)
{
// Create instruction
EncryptionInstructions instructions = EncryptionUtils.GenerateInstructions(this.encryptionMaterials);
EncryptionUtils.AddUnencryptedContentLengthToMetadata(putObjectRequest);
// Encrypt the object data with the instruction
putObjectRequest.InputStream = EncryptionUtils.EncryptRequestUsingInstruction(putObjectRequest.InputStream, instructions);
// Create request for uploading instruction file
PutObjectRequest instructionFileRequest = EncryptionUtils.CreateInstructionFileRequest(putObjectRequest, instructions);
S3ClientForInstructionFile.PutObject(instructionFileRequest);
}
/// <summary>
/// Performs encryption for PutObject and MultiPartUpload,
/// also adding encryption information to object metadata or
/// instruction file
/// </summary>
/// <param name="request">AmazonWebServiceRequest on which encryption is performed </param>
protected override void ProcessPreRequestHandlers(AmazonWebServiceRequest request)
{
base.ProcessPreRequestHandlers(request);
var putObjectRequest = request as PutObjectRequest;
if (putObjectRequest != null)
{
if (this.amazonS3CryptoConfig.StorageMode == CryptoStorageMode.InstructionFile)
{
GenerateEncryptedObjectRequestUsingInstructionFile(putObjectRequest);
}
else
{
GenerateEncryptedObjectRequestUsingMetadata(putObjectRequest);
}
}
var initiateMultiPartRequest = request as InitiateMultipartUploadRequest;
if (initiateMultiPartRequest != null)
{
EncryptionInstructions instructions = EncryptionUtils.GenerateInstructions(this.encryptionMaterials);
if (this.amazonS3CryptoConfig.StorageMode == CryptoStorageMode.ObjectMetadata)
{
EncryptionUtils.UpdateMetadataWithEncryptionInstructions(initiateMultiPartRequest, instructions);
}
initiateMultiPartRequest.EnvelopeKey = instructions.EnvelopeKey;
initiateMultiPartRequest.IV = instructions.InitializationVector;
}
var uploadPartRequest = request as UploadPartRequest;
if (uploadPartRequest != null)
{
GenerateEncryptedUploadPartRequest(uploadPartRequest);
}
}
/// <summary>
/// Performs decryption of data by getting encryption information
/// from object metadata or instruction file.
/// </summary>
/// <param name="response">AmazonWebServiceResponse on which decryption is performed</param>
/// <param name="request">IRequest</param>
/// <param name="webResponseData">IWebResponseData</param>
protected override void ProcessResponseHandlers(AmazonWebServiceResponse response, IRequest request, IWebResponseData webResponseData)
{
base.ProcessResponseHandlers(response, request, webResponseData);
var initiateMultiPartUploadRequest = request.OriginalRequest as InitiateMultipartUploadRequest;
var initiateMultiPartResponse = response as InitiateMultipartUploadResponse;
if (initiateMultiPartResponse != null)
{
byte[] envelopeKey = initiateMultiPartUploadRequest.EnvelopeKey;
byte[] iv = initiateMultiPartUploadRequest.IV;
UploadPartEncryptionContext contextForEncryption = new UploadPartEncryptionContext();
contextForEncryption.EnvelopeKey = envelopeKey;
contextForEncryption.NextIV = iv;
contextForEncryption.FirstIV = iv;
contextForEncryption.PartNumber = 0;
//Add context for encryption of next part
currentMultiPartUploadKeys.Add(initiateMultiPartResponse.UploadId, contextForEncryption);
}
var uploadPartRequest = request.OriginalRequest as UploadPartRequest;
var uploadPartResponse = response as UploadPartResponse;
if (uploadPartResponse != null)
{
string uploadID = uploadPartRequest.UploadId;
UploadPartEncryptionContext encryptedUploadedContext = null;
if (!currentMultiPartUploadKeys.TryGetValue(uploadID, out encryptedUploadedContext))
{
throw new AmazonS3Exception("encryption context for multi part upload not found");
}
if (uploadPartRequest.IsLastPart == false)
{
object stream = null;
if (!uploadPartRequest.RequestState.TryGetValue(S3CryptoStream, out stream))
{
throw new AmazonS3Exception("cannot retrieve S3 crypto stream from request state, hence cannot get Initialization vector for next uploadPart ");
}
var encryptionStream = stream as AESEncryptionUploadPartStream;
encryptedUploadedContext.NextIV = encryptionStream.InitializationVector;
}
}
var getObjectResponse = response as GetObjectResponse;
if (getObjectResponse != null)
{
if (EncryptionUtils.IsEncryptionInfoInMetadata(getObjectResponse) == true)
{
DecryptObjectUsingMetadata(getObjectResponse);
}
else
{
GetObjectResponse instructionFileResponse = null;
try
{
GetObjectRequest instructionFileRequest = EncryptionUtils.GetInstructionFileRequest(getObjectResponse);
instructionFileResponse = S3ClientForInstructionFile.GetObject(instructionFileRequest);
}
catch (AmazonServiceException ace)
{
throw new AmazonServiceException(string.Format(CultureInfo.InvariantCulture, "Unable to decrypt data for object {0} in bucket {1}",
getObjectResponse.Key, getObjectResponse.BucketName), ace);
}
if (EncryptionUtils.IsEncryptionInfoInInstructionFile(instructionFileResponse) == true)
{
DecryptObjectUsingInstructionFile(getObjectResponse, instructionFileResponse);
}
}
}
var completeMultiPartUploadRequest = request.OriginalRequest as CompleteMultipartUploadRequest;
var completeMultipartUploadResponse = response as CompleteMultipartUploadResponse;
if (completeMultipartUploadResponse != null)
{
if (amazonS3CryptoConfig.StorageMode == CryptoStorageMode.InstructionFile)
{
UploadPartEncryptionContext context = currentMultiPartUploadKeys[completeMultiPartUploadRequest.UploadId];
byte[] envelopeKey = context.EnvelopeKey;
byte[] iv = context.FirstIV;
byte[] encryptedEnvelopeKey = EncryptionUtils.EncryptEnvelopeKey(envelopeKey, this.encryptionMaterials);
EncryptionInstructions instructions = new EncryptionInstructions(EncryptionMaterials.EmptyMaterialsDescription, envelopeKey, encryptedEnvelopeKey, iv);
PutObjectRequest instructionFileRequest = EncryptionUtils.CreateInstructionFileRequest(completeMultiPartUploadRequest, instructions);
S3ClientForInstructionFile.PutObject(instructionFileRequest);
}
//Clear Context data since encryption is completed
currentMultiPartUploadKeys.Clear();
}
}
