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Rijndael BlockSize vs GetBytes?

What's the difference between using BlockSize or GetBytes?

var keyGen = new Rfc2898DeriveBytes(pass, 8)
var aes = Rijndael.Create(); //Rijndael
aes.Padding = PaddingMode.PKCS7;
aes.IV = keyGen.GetBytes(aes.BlockSize / 8);
aes.Key = keyGen.GetBytes(aes.KeySize / 8);

- VS -
aes.IV = keyGen.GetBytes(16);
aes.Key = keyGen.GetBytes(32);

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mlan

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pointeman

ASKER

Okay, so BlockSize is measured in bits and / 8 converts to needed bytes for GetBytes. I fine most postings on the Internet using BlockSize. It gets a little confusing when I find two ways of returning the same result.
[IV]
aes.IV = keyGen.GetBytes(aes.BlockSize / 8); // BlockSize(default 128) / 8 = 16
- OR -
aes.IV = keyGen.GetBytes(16);
[Key]
aes.Key = keyGen.GetBytes(aes.KeySize / 8); // BlockSize(default 256) / 8 = 32
- OR -
aes.Key = keyGen.GetBytes(32);

Note: I experimented by encrypting a string message using aes.KeySize/8 and successfully decrypted using GetBytes(32)...
I wasn't sure if there is an advantage....

SOLUTION