/**
* {@inheritDoc}
*
* <p><b>NOTE:</b> Because the encryption process requires context from block N-1 in order to
* encrypt block N, parts uploaded with the AmazonS3EncryptionClient (as opposed to the normal
* AmazonS3Client) must be uploaded serially, and in order. Otherwise, the previous encryption
* context isn't available to use when encrypting the current part.
*/
@Override
public UploadPartResult uploadPart(UploadPartRequest uploadPartRequest)
throws AmazonClientException, AmazonServiceException {
appendUserAgent(uploadPartRequest, USER_AGENT);
boolean isLastPart = uploadPartRequest.isLastPart();
String uploadId = uploadPartRequest.getUploadId();
boolean partSizeMultipleOfCipherBlockSize =
uploadPartRequest.getPartSize() % JceEncryptionConstants.SYMMETRIC_CIPHER_BLOCK_SIZE == 0;
if (!isLastPart && !partSizeMultipleOfCipherBlockSize) {
throw new AmazonClientException(
"Invalid part size: part sizes for encrypted multipart uploads must be multiples "
+ "of the cipher block size ("
+ JceEncryptionConstants.SYMMETRIC_CIPHER_BLOCK_SIZE
+ ") with the exception of the last part. "
+ "Otherwise encryption adds extra padding that will corrupt the final object.");
}
// Generate the envelope symmetric key and initialize a cipher to encrypt the object's data
EncryptedUploadContext encryptedUploadContext = currentMultipartUploadSecretKeys.get(uploadId);
if (encryptedUploadContext == null)
throw new AmazonClientException(
"No client-side information available on upload ID " + uploadId);
SecretKey envelopeSymmetricKey = encryptedUploadContext.getEnvelopeEncryptionKey();
byte[] iv = encryptedUploadContext.getNextInitializationVector();
CipherFactory cipherFactory =
new CipherFactory(
envelopeSymmetricKey, Cipher.ENCRYPT_MODE, iv, this.cryptoConfig.getCryptoProvider());
// Create encrypted input stream
InputStream encryptedInputStream =
EncryptionUtils.getEncryptedInputStream(uploadPartRequest, cipherFactory);
uploadPartRequest.setInputStream(encryptedInputStream);
// The last part of the multipart upload will contain extra padding from the encryption process,
// which
// changes the
if (uploadPartRequest.isLastPart()) {
// We only change the size of the last part
long cryptoContentLength =
EncryptionUtils.calculateCryptoContentLength(
cipherFactory.createCipher(), uploadPartRequest);
if (cryptoContentLength > 0) uploadPartRequest.setPartSize(cryptoContentLength);
if (encryptedUploadContext.hasFinalPartBeenSeen()) {
throw new AmazonClientException(
"This part was specified as the last part in a multipart upload, but a previous part was already marked as the last part. "
+ "Only the last part of the upload should be marked as the last part, otherwise it will cause the encrypted data to be corrupted.");
}
encryptedUploadContext.setHasFinalPartBeenSeen(true);
}
// Treat all encryption requests as input stream upload requests, not as file upload requests.
uploadPartRequest.setFile(null);
uploadPartRequest.setFileOffset(0);
UploadPartResult result = super.uploadPart(uploadPartRequest);
if (encryptedInputStream instanceof ByteRangeCapturingInputStream) {
ByteRangeCapturingInputStream bris = (ByteRangeCapturingInputStream) encryptedInputStream;
encryptedUploadContext.setNextInitializationVector(bris.getBlock());
} else {
throw new AmazonClientException("Unable to access last block of encrypted data");
}
return result;
}
private static CipherInputStream createCipherInputStream(
InputStream input, CipherFactory cipherFactory) {
Cipher cipher = cipherFactory.createCipher();
return new CipherInputStream(input, cipher);
}