System.Security.Cryptography.RC2CryptoServiceProvider.CreateTransform C# (CSharp) Method

        private ICryptoTransform CreateTransform(byte[] rgbKey, byte[] rgbIV, bool encrypting)
        {
            // note: rgbIV is guaranteed to be cloned before this method, so no need to clone it again

            long keySize = rgbKey.Length * (long)BitsPerByte;
            if (keySize > int.MaxValue || !((int)keySize).IsLegalSize(this.LegalKeySizes))
                throw new ArgumentException(SR.Cryptography_InvalidKeySize, nameof(rgbKey));

            if (rgbIV == null)
            {
                if (Mode.UsesIv())
                {
                    rgbIV = new byte[8];
                    s_rng.GetBytes(rgbIV);
                }
            }
            else
            {
                // We truncate IV's that are longer than the block size to 8 bytes : this is
                // done to maintain backward desktop compatibility with the behavior shipped in V1.x.
                // The call to set the IV in CryptoAPI will ignore any bytes after the first 8
                // bytes. We'll still reject IV's that are shorter than the block size though.
                if (rgbIV.Length < 8)
                    throw new CryptographicException(SR.Cryptography_InvalidIVSize);
            }

            int effectiveKeySize = EffectiveKeySizeValue == 0 ? (int)keySize : EffectiveKeySize;
            BasicSymmetricCipher cipher = new BasicSymmetricCipherCsp(CapiHelper.CALG_RC2, Mode, BlockSize / BitsPerByte, rgbKey, effectiveKeySize, !UseSalt, rgbIV, encrypting);
            return UniversalCryptoTransform.Create(Padding, cipher, encrypting);
        }