using Org.BouncyCastle.Crypto.Parameters; using Org.BouncyCastle.Crypto.Utilities; using System; namespace Org.BouncyCastle.Crypto.Fpe { public class FpeFf3_1Engine : FpeEngine { public FpeFf3_1Engine() : this(AesUtilities.CreateEngine()) { } public FpeFf3_1Engine(IBlockCipher baseCipher) : base(baseCipher) { if (FpeEngine.IsOverrideSet(SP80038G.FPE_DISABLED)) throw new InvalidOperationException("FPE disabled"); } public override void Init(bool forEncryption, ICipherParameters parameters) { base.forEncryption = forEncryption; fpeParameters = (FpeParameters)parameters; baseCipher.Init(!fpeParameters.UseInverseFunction, fpeParameters.Key.Reverse()); if (fpeParameters.GetTweak().Length != 7) throw new ArgumentException("tweak should be 56 bits"); } protected override int EncryptBlock(byte[] inBuf, int inOff, int length, byte[] outBuf, int outOff) { byte[] sourceArray; if (fpeParameters.Radix > 256) { if ((length & 1) != 0) throw new ArgumentException("input must be an even number of bytes for a wide radix"); ushort[] array = Pack.BE_To_UInt16(inBuf, inOff, length / 2); ushort[] array2 = SP80038G.EncryptFF3_1w(baseCipher, fpeParameters.Radix, fpeParameters.GetTweak(), array, 0, array.Length); sourceArray = Pack.UInt16_To_BE(array2, 0, array2.Length); } else sourceArray = SP80038G.EncryptFF3_1(baseCipher, fpeParameters.Radix, fpeParameters.GetTweak(), inBuf, inOff, length); Array.Copy(sourceArray, 0, outBuf, outOff, length); return length; } protected override int DecryptBlock(byte[] inBuf, int inOff, int length, byte[] outBuf, int outOff) { byte[] sourceArray; if (fpeParameters.Radix > 256) { if ((length & 1) != 0) throw new ArgumentException("input must be an even number of bytes for a wide radix"); ushort[] array = Pack.BE_To_UInt16(inBuf, inOff, length / 2); ushort[] array2 = SP80038G.DecryptFF3_1w(baseCipher, fpeParameters.Radix, fpeParameters.GetTweak(), array, 0, array.Length); sourceArray = Pack.UInt16_To_BE(array2, 0, array2.Length); } else sourceArray = SP80038G.DecryptFF3_1(baseCipher, fpeParameters.Radix, fpeParameters.GetTweak(), inBuf, inOff, length); Array.Copy(sourceArray, 0, outBuf, outOff, length); return length; } } }