> From: Andrew Arnott [mailto:andrewarn...@gmail.com] > > I want to programmatically enumerate the allowed key sizes for a given > Cipher. Is there an API to do this?
If it's a .NET cipher, you can use the LegalKeySizes property https://msdn.microsoft.com/en-us/library/system.security.cryptography.symmetricalgorithm.legalkeysizes(v=vs.110).aspx If it's a BouncyCastle derivative of IBlockCipher, there is no such analogous property of IBlockCipher. In fact, by looking at AESFastEngine, the only time the key size seems to be checked is during GenerateWorkingKey(), which is called by Init(). There, it's hard-coded in a private method, to check the Key length, must be 128, 192, or 256. Based on this, I'd say there is no programmatic way, nor even an enum you could use.
