windows 8 - How do we know SymmetricAlgorithmNames::AesCbc is 128 bit or 256 bit in WinRT? -

i using symmetricalgorithmnames::aescbc , symmetricalgorithmnames::descbc algorithms in data encryption implementation in winrt.

i need ensure these algorithms @ least 128 bit algorithms not evident algorithm names. same evident if using opensll (eg. evp_aes_128_cfb128()).

can tell me whether symmetricalgorithmnames::aescbc 128-bit or 256-bit or other?

thanks in advance.

the algorithm automatically uses whatever size key provide it. when call symmetrickeyalgorithmprovider.createsymmetrickey , pass in ibuffer keymaterial, whatever contained in `ibuffer determine bit length of encryption. if pass in 16 randomly-generated bytes, (16*8) 128-bit, symmetric encryption. if pass in 32 bytes, give 256.

as says in spec, can use cryptographicbuffer.generaterandom secure, random bytes.

happy coding!