public override void Write(byte[] buffer, int offset, int count)
{
// Keep buffering until we have 16 bytes of IV.
if (this.bufferIV && this.position < 16)
{
int bytesToCopy = 16 - (int)this.position;
bytesToCopy = count > bytesToCopy ? bytesToCopy : count;
Array.Copy(buffer, offset, this.iv, (int)this.position, bytesToCopy);
this.position += bytesToCopy;
offset += bytesToCopy;
count -= bytesToCopy;
if (this.position < 16)
{
return;
}
}
// Wrap user stream with LengthLimitingStream. This stream will be used to discard the extra bytes we downloaded in order to deal with AES block size.
// Create crypto stream around the length limiting stream once per download and start writing to it. During retries, the state is maintained and
// new crypto streams will not be created each time.
if (this.cryptoStream == null)
{
LengthLimitingStream lengthLimitingStream = new LengthLimitingStream(this.userStream, this.discardFirst, this.userProvidedLength);
this.cryptoStream = this.encryptionPolicy.DecryptBlob(lengthLimitingStream, this.metadata, out this.transform, this.requireEncryption, iv: !this.bufferIV ? null : this.iv, noPadding: this.noPadding);
}
// Route the remaining data through the crypto stream.
if (count > 0)
{
this.cryptoStream.Write(buffer, offset, count);
this.position += count;
}
}
public override IAsyncResult BeginWrite(byte[] buffer, int offset, int count, AsyncCallback callback, object state)
{
StorageAsyncResult <NullType> storageAsyncResult = new StorageAsyncResult <NullType>(callback, state);
// Keep buffering until we have 16 bytes of IV.
if (this.bufferIV && this.position < 16)
{
int bytesToCopy = 16 - (int)this.position;
bytesToCopy = count > bytesToCopy ? bytesToCopy : count;
Array.Copy(buffer, offset, this.iv, (int)this.position, bytesToCopy);
this.position += bytesToCopy;
offset += bytesToCopy;
count -= bytesToCopy;
if (this.position < 16)
{
storageAsyncResult.OnComplete();
return(storageAsyncResult);
}
}
// Wrap user stream with LengthLimitingStream. This stream will be used to discard the extra bytes we downloaded in order to deal with AES block size.
// Create crypto stream around the length limiting stream once per download and start writing to it. During retries, the state is maintained and
// new crypto streams will not be created each time.
if (this.cryptoStream == null)
{
LengthLimitingStream lengthLimitingStream = new LengthLimitingStream(this.userStream, this.discardFirst, this.userProvidedLength);
this.cryptoStream = this.encryptionPolicy.DecryptBlob(lengthLimitingStream, this.metadata, out this.transform, this.requireEncryption, iv: !this.bufferIV ? null : this.iv, noPadding: this.noPadding);
}
if (count <= 0)
{
storageAsyncResult.OnComplete();
}
else
{
// Route the remaining data through the crypto stream.
storageAsyncResult.OperationState = count;
this.cryptoStream.BeginWrite(buffer, offset, count, this.WriteStreamCallback, storageAsyncResult);
}
return(storageAsyncResult);
}
