/// <summary>
/// Unpacks from bytes.
/// </summary>
/// <param name="requestBytes">The request bytes.</param>
/// <param name="rsaProvider">The RSA provider.</param>
/// <param name="aesProvider">The aes provider.</param>
/// <returns></returns>
public static VirtualSecuredRequestRawMessage UnpackRequestFromBytes(this byte[] requestBytes, RSACryptoServiceProvider rsaProvider, out RijndaelProvider aesProvider)
{
// Byte[] composition: [Schema Version]{1}[UTC Stamp]{4}[Encrypted Security Key Length Indication]{2+2}[Encrypted Security Key]{M+N}[Encrypted Body]{L}.
aesProvider = null;
try
{
rsaProvider.CheckNullObject(nameof(rsaProvider));
requestBytes.CheckNullOrEmptyCollection(nameof(requestBytes));
var result = new VirtualSecuredRequestRawMessage
{
// Index1
SchemaVersion = Convert.ToInt32(requestBytes[0])
};
var currentIndex = 1;
// Index2
var stampBytes = requestBytes.Read(_stampIndicationByteLength, ref currentIndex);
result.Stamp = GetUtcStampFromOffsetBytes(stampBytes);
ValidateStamp(result.Stamp);
// Index3
var primaryKeyLengthBytes = requestBytes.Read(_securityKeyIndicationByteLength, ref currentIndex);
var primaryKeyLength = BitConverter.ToUInt16(primaryKeyLengthBytes, 0);
var secondaryKeyLengthBytes = requestBytes.Read(_securityKeyIndicationByteLength, ref currentIndex);
var secondaryKeyLength = BitConverter.ToUInt16(secondaryKeyLengthBytes, 0);
// Index4
var primaryKeyBytes = requestBytes.Read(primaryKeyLength, ref currentIndex);
result.SymmetricPrimaryKey = rsaProvider.Decrypt(primaryKeyBytes, true);
var secondaryKeyBytes = requestBytes.Read(secondaryKeyLength, ref currentIndex);
result.SymmetricSecondaryKey = secondaryKeyBytes == null ? null : rsaProvider.Decrypt(secondaryKeyBytes, true);
aesProvider = new AesKeys {
KeySize = dwKeySize, InitializationVector = result.SymmetricSecondaryKey, Key = result.SymmetricPrimaryKey
}.CreateAesProvider();
// Index5
var dataBytes = requestBytes.SubArray(currentIndex);
result.Data = aesProvider.DecryptAes(dataBytes);
return(result);
}
catch (Exception ex)
{
throw ex.Handle();
}
}
