Specified key is not a valid size for this algorithm

Question

I have with this code:

RijndaelManaged rijndaelCipher = new RijndaelManaged();

            // Set key and IV
            rijndaelCipher.Key = Convert.FromBa         


        

Answer 1

Use the random number generator class (RNGCryptoServiceProvider) to fill a specified buffer with random bytes as follows:

var numberOfBits = 256; // or 192 or 128, however using a larger bit size renders the encrypted data harder to decipher

var ivBytes = new byte[numberOfBits / 8]; // 8 bits per byte

new RNGCryptoServiceProvider().GetBytes(ivBytes);

var rijndaelManagedCipher = new RijndaelManaged();

//Don't forget to set the explicitly set the block size for the IV if you're not using the default of 128

rijndaelManagedCipher.BlockSize = 256;

rijndaelManagedCipher.IV = ivBytes;

Note the same process could be used to derive a key. Hope this helps.