private void WriteFirstEncryptedBlock(MemoryStream bufferedOutputStream)
{
// Create the encryptor that will be used to transform the data. This will use the key and IV
// that were generated when the aes object was created, and will only be used for this stream.
this.cryptoTransform = this.aes.CreateEncryptor();
RSAPKCS1KeyExchangeFormatter keyFormatter = new RSAPKCS1KeyExchangeFormatter(this.rsa);
byte[] keyEncrypted = keyFormatter.CreateKeyExchange(this.aes.Key, this.aes.GetType());
EncryptedFileHeader header = new EncryptedFileHeader
{
EncryptedKey = keyEncrypted,
IV = this.aes.IV,
CertificateThumbprint = AdapterBase.HexToBytes(this.encryptionCertificate.Thumbprint)
};
short padding;
if (this.Mode == EncryptionMode.Encrypt)
{
header.OriginalFileLength = this.sourceFileSize;
header.EncryptedFileLength = CalculateEncryptedFileSize(this.sourceFileSize, out padding);
header.PaddingLength = padding;
}
else
{
header.EncryptedFileLength = this.sourceFileSize;
header.OriginalFileLength = CalculateDecryptedFileSize(this.sourceFileSize, out padding);
header.PaddingLength = padding;
}
header.WriteToStream(bufferedOutputStream);
this.firstBlockTransformed = true;
}
